PT J
AU TAYLOR, R
   LANGLEY, GJ
   KROTO, HW
   WALTON, DRM
AF TAYLOR, R
   LANGLEY, GJ
   KROTO, HW
   WALTON, DRM
TI FORMATION OF C60 BY PYROLYSIS OF NAPHTHALENE
SO NATURE
LA English
DT Article
ID fullerenes c60; carbon; c-60; buckminsterfullerene; spectra; flames; form; c-70; ions; c70
AB THE formation of bulk quantities of C60 by arc discharge between carbon electrodes in an atmosphere of helium1 or argon2,3 has led to an explosion in fullerene research. Methods for improving the rate of fullerene production have included increasing the reactor size and the diameter of the carbon rods, and varying the rate of rod consumption and helium pressure4. Systems using several rods have also been employed5,6. The ideal method, however, would involve a continuous process that does not require rod replacement. Approaches using carbon granules6 and powders7 have been reported, as well as combustion methods using hydrocarbons8,9. Here we report the formation of C60 and C70 by pyrolysis of naphthalene at approximately 1,000-degrees-C. C60 and C70 are formed by the 'patching together' of six and seven naphthalene molecules respectively, as demonstrated by mass-spectrometric analysis of intermediate products. These results point to a continuous method of fullerene formation, and also show that closed fullerene cages can be built from well defined aromatic fragments.
C1 UNIV SOUTHAMPTON,DEPT CHEM,SOUTHAMPTON SO9 5NH,HANTS,ENGLAND.
C3 University of Southampton
RP TAYLOR, R (corresponding author), UNIV SUSSEX,SCH CHEM & MOLEC SCI,BRIGHTON BN1 9QJ,E SUSSEX,ENGLAND.
NR 35
TC 172
Z9 186
U1 1
U2 115
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 23
PY 1993
VL 366
IS 6457
BP 728
EP 731
DI 10.1038/366728a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MN264
UT WOS:A1993MN26400023
DA 2026-03-10
ER

PT J
AU OLIVERA, A
   SPIEGEL, S
AF OLIVERA, A
   SPIEGEL, S
TI SPHINGOSINE-1-PHOSPHATE AS 2ND MESSENGER IN CELL-PROLIFERATION INDUCED BY PDGF AND FCS MITOGENS
SO NATURE
LA English
DT Article
ID protein-kinase-c; endogenous ganglioside; signal transduction; phosphatidic-acid; free sphingosine; activation; hydrolysis; receptor; liver
AB GROWTH signalling networks that use glycerophospholipid metabolites as second messengers have been well characterized1,2, but less is known of the second messengers derived from sphingolipids3,4, another major class of membrane lipids. A tantalizing fink between sphingolipids and cellular proliferation has emerged from the discovery that the sphingolipid metabolites sphingosine and sphingosine-1-phosphate stimulate growth of quiescent Swiss 3T3 fibroblasts by a pathway that is independent of protein kinase C5,6. Sphingosine-1-phosphate is rapidly produced from sphingosine and may mediate its biological effects6. Furthermore, sphingosine-1-phosphate triggers the dual signal transduction pathways of calcium mobilization6,7 and activation of phospholipase D8, prominent events in the control of cellular proliferation. Here we report that activation of sphingosine kinase and the formation of sphingosine-1-phosphate are important in the signal transduction pathways activated by the potent mitogens platelet-derived growth factor (PDGF) and fetal calf serum (FCS).
C1 GEORGETOWN UNIV,MED CTR,DEPT BIOCHEM & MOLEC BIOL,WASHINGTON,DC 20007.
C3 Georgetown University
NR 29
TC 840
Z9 925
U1 1
U2 26
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 557
EP 560
DI 10.1038/365557a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100058
PM 8413613
DA 2026-03-10
ER

PT J
AU UTZ, U
   BIDDISON, WE
   MCFARLAND, HF
   MCFARLIN, DE
   FLERLAGE, M
   MARTIN, R
AF UTZ, U
   BIDDISON, WE
   MCFARLAND, HF
   MCFARLIN, DE
   FLERLAGE, M
   MARTIN, R
TI SKEWED T-CELL RECEPTOR REPERTOIRE IN GENETICALLY IDENTICAL-TWINS CORRELATES WITH MULTIPLE-SCLEROSIS
SO NATURE
LA English
DT Article
ID myelin basic-protein; genes; glycoprotein; individuals; disease; clones; usage; acid
AB ALTHOUGH the cause of multiple sclerosis (MS) is unknown, it is thought to involve a T cell-mediated autoimmune mechanism. Susceptibility to the disease is influenced by genetic factors such as genes of the HLA and T-cell receptor (TCR) complex1-6. Other evidence for a genetic influence includes the low incidence in certain ethnic groups7, the increased risk if there are affected family members8 and the increased concordance rate for disease in monozygotic twin pairs (26%)9, compared to dizygotic twins. Epidemiological studies indicate that there may be an additional role for envirommental factors. Although the target antigen(s) are not yet identified, several myelin or myelin-associated proteins have been suspected10-12, among them myelin basic protein. A lack of genetically comparable controls has impaired the analysis of the T-cell response in MS patients and caused disagreement on TCR usage in the disease13-15. Here we analyse the role of TCR genes in MS by comparing TCR usage in discordant versus concordant monozygotic twins in response to-self and foreign antigens. We find that after stimulation with myelin basic protein or tetanus toxoid, control twin sets as well as concordant twin sets select similar Valpha chains. Only the discordant twin sets select different TCRs after stimulation with antigens. Thus exogenous factors or the disease shape the TCR repertoire in MS patients, as seen by comparison with unaffected genetically identical individuals. This skewing of the TCR repertoire could contribute to the pathogenesis of MS and other T-cell-mediated diseases.
C1 UNIV TUBINGEN,SCH MED,DEPT NEUROL,W-7400 TUBINGEN 1,GERMANY.
C3 Eberhard Karls University of Tubingen
RP UTZ, U (corresponding author), NINCDS,NEUROIMMUNOL BRANCH,BLDG 10,RM 5B-16,BETHESDA,MD 20892, USA.
NR 22
TC 124
Z9 132
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 243
EP 247
DI 10.1038/364243a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300059
PM 7686632
DA 2026-03-10
ER

PT J
AU HORANYI, M
   MORFILL, G
   GRUN, E
AF HORANYI, M
   MORFILL, G
   GRUN, E
TI MECHANISM FOR THE ACCELERATION AND EJECTION OF DUST GRAINS FROM JUPITER MAGNETOSPHERE
SO NATURE
LA English
DT Article
AB PERHAPS the most unexpected finding of the Ulysses mission so far has been the detection of quasi-periodic streams of high-velocity, submicrometre-sized dust particles during the spacecraft's encounter with Jupiter1. The impact geometry clearly shows that these small grains originate in the jovian system, but it is surprising that any dust can escape Jupiter's gravitational influence. Here we show how the Ulysses dust events could result from the acceleration and subsequent ejection of small grains by Jupiter's magnetosphere. Dust grains entering the plasma environment of the magnetosphere become charged, with the result that their motion is then determined by both electromagnetic and gravitational forces. We have modelled this process and find that only those particles in a certain size range gain sufficient energy to escape the jovian system. Moreover, if Io is assumed to be the source of the dust grains, its location in geographic and geomagnetic coordinates determines the exit direction of the escaping particles, providing a possible explanation for the observed periodicities. The calculated mass and velocity ranges of the escaping dust grains are consistent with the Ulysses findings.
C1 MAX PLANCK INST EXTRATERR PHYS,W-8046 GARCHING,GERMANY.
   MAX PLANCK INST NUCL PHYS,W-6900 HEIDELBERG 1,GERMANY.
C3 Max Planck Society; Max Planck Society
RP HORANYI, M (corresponding author), UNIV COLORADO,ATMOSPHER & SPACE PHYS LAB,BOULDER,CO 80309, USA.
NR 5
TC 261
Z9 269
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 144
EP 146
DI 10.1038/363144a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100041
DA 2026-03-10
ER

PT J
AU IIJIMA, S
   ICHIHASHI, T
AF IIJIMA, S
   ICHIHASHI, T
TI SINGLE-SHELL CARBON NANOTUBES OF 1-NM DIAMETER
SO NATURE
LA English
DT Article
AB CARBON nanotubes1 are expected to have a wide variety of interesting properties. Capillarity in open tubes has already been demonstrated2-5, while predictions regarding their electronic structure6-8 and mechanical strength9 remain to be tested. To examine the properties of these structures, one needs tubes with well defined morphologies, length, thickness and a number of concentric shells; but the normal carbon-arc synthesis10,11 yields a range of tube types. In particular, most calculations have been concerned with single-shell tubes, whereas the carbon-arc synthesis produces almost entirely multi-shell tubes. Here we report the synthesis of abundant single-shell tubes with diameters of about one nanometre. Whereas the multi-shell nanotubes are formed on the carbon cathode, these single-shell tubes grow in the gas phase. Electron diffraction from a single tube allows us to confirm the helical arrangement of carbon hexagons deduced previously for multi-shell tubes1.
RP IIJIMA, S (corresponding author), NEC CORP LTD, FUNDAMENTAL RES LABS, 34 MIYUKIGAOKA, TSUKUBA, IBARAKI 305, JAPAN.
NR 18
TC 7567
Z9 8849
U1 21
U2 2044
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 603
EP 605
DI 10.1038/363603a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900046
DA 2026-03-10
ER

PT J
AU OGASAWARA, J
   WATANABEFUKUNAGA, R
   ADACHI, M
   MATSUZAWA, A
   KASUGAI, T
   KITAMURA, Y
   ITOH, N
   SUDA, T
   NAGATA, S
AF OGASAWARA, J
   WATANABEFUKUNAGA, R
   ADACHI, M
   MATSUZAWA, A
   KASUGAI, T
   KITAMURA, Y
   ITOH, N
   SUDA, T
   NAGATA, S
TI LETHAL EFFECT OF THE ANTI-FAS ANTIBODY IN MICE
SO NATURE
LA English
DT Article
ID tumor-necrosis-factor; cell-surface antigen; monoclonal-antibody; apoptosis; expression; receptor; cachectin; death; cdna
AB DURING mammalian development, many cells are programmed to die1,2 most mediated by apoptosis3. The Fas antigen4 coded by the structural gene for mouse lymphoproliferation mutation (lpr)5,6, is a cell surface protein belonging to the tumour necrosis factor/nerve growth factor receptor family7,8, and mediates apoptosis7. The Fas antigen messenger RNA is expressed in the thymus, liver, heart, lung and ovary8. We prepared a monoclonal antibody against mouse Fas antigen, which immunoprecipitated the antigen (M(r) 45K) and had cytolytic activity against cell lines expressing mouse Fas antigen. We report here that staining of mouse thymocytes with the antibody indicated that thymocytes from the wild-type and lpr(cg) mice expressed the Fas antigen, whereas little expression of the Fas antigen was found in lpr mice. Intraperitoneal administration of the anti-Fas antibody into mice rapidly killed the wild-type mice but neither lpr nor lpr(cg) mice. Biochemical, histological and electron microscope analyses indicated severe damage of the liver by apoptosis. These findings suggest that the Fas antigen is important in programmed cell death in the liver, and may be involved in fulminant hepatitis in some cases.
C1 OSAKA BIOSCI INST, 6-2-4 FURUEDAI, SUITA, OSAKA 565, JAPAN.
   OSAKA CITY INST PUBL HLTH & ENVIRONM SCI, TENNOJI KU, OSAKA 543, JAPAN.
   UNIV TOKYO, INST MED SCI, LAB ANIM RES CTR, TOKYO 108, JAPAN.
   OSAKA UNIV, SCH MED, DEPT PATHOL, SUITA, OSAKA 565, JAPAN.
C3 University of Tokyo; University of Osaka
NR 27
TC 1829
Z9 1950
U1 0
U2 29
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 806
EP 809
DI 10.1038/364806a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100057
PM 7689176
DA 2026-03-10
ER

PT J
AU MARKEVITCH, M
   SUNYAEV, RA
   PAVLINSKY, M
AF MARKEVITCH, M
   SUNYAEV, RA
   PAVLINSKY, M
TI 2 SOURCES OF DIFFUSE-X-RAY EMISSION FROM THE GALACTIC-CENTER
SO NATURE
LA English
DT Article
AB THE weak extended X-ray source at the Galactic Centre has so far lacked a reasonable explanation. Measurements of this roughly elliptical source from the Ginga satellite revealed1 emission in the 6.7-keV line of ionized iron, indicating that the X-rays originate in an optically thin plasma. But to account for the hard X-ray spectrum, this plasma needs to be very hot - too hot, in fact, to be confined by the gravitational potential of the Galactic Centre2. We have recently shown3 that the morphology of the emitting region changes at energies above 11 keV: the source becomes extended in the galactic plane, resembling the distribution of the molecular gas clouds in this region. Here we report the detection of a pronounced absorption feature in the emission spectrum in the energy range 8-11 keV. This result, combined with the changing spatial distribution, suggests that the high-energy emissions arise from the scattering of X-rays from the nearby compact sources by the dense molecular clouds. As no comparable absorption feature is seen at lower energies, the softer X-ray emissions may still be understood in terms of thermal emission from a plasma, but the required temperature is no longer unreasonably high.
RP MARKEVITCH, M (corresponding author), MOSCOW SPACE RES INST,PROFSOYUZNAVA 84-32,MOSCOW 117810,RUSSIA.
NR 14
TC 31
Z9 31
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 40
EP 42
DI 
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800049
DA 2026-03-10
ER

PT J
AU WETZEL, LR
   WIENS, DA
   KLEINROCK, MC
AF WETZEL, LR
   WIENS, DA
   KLEINROCK, MC
TI EVIDENCE FROM EARTHQUAKES FOR BOOKSHELF FAULTING AT LARGE NON-TRANSFORM RIDGE OFFSETS
SO NATURE
LA English
DT Article
ID propagating rift; galapagos 95.5-degrees-w; reflectivity method; block rotations; plate motions; deep-tow; pacific; kinematics; seismicity; tectonics
AB MIGRATING non-transform offsets, which occur along mid-ocean ridges when a propagating segment gradually elongates and takes over spreading from a neighbouring 'doomed' rift segment1-3, represent a significant modification of the plate tectonic paradigm4. The migrating offset zone between the two spreading segments is clearly a locus of significant deformation, but the mechanism of this deformation has been controversial. Here we use the source parameters and locations of earthquakes at such offsets to discriminate between previously proposed models2,4-7 . Earthquakes at large non-transform offsets at medium and fast spreading rates show strike-slip mechanisms, with nodal planes rotated relative to the expected transform fault orientation. One set of nodal planes (presumably corresponding to the fault planes) is parallel to curved sea-floor lineaments which show increased rotation as a function of position in the deforming zone. A bookshelf faulting model in which initially ridge-parallel faults are rotated by simple shear is consistent with the observed lineament orientations, focal mechanisms and earthquake distributions.
C1 WOODS HOLE OCEANOG INST,DEPT GEOL & GEOPHYS,WOODS HOLE,MA 02543.
C3 Woods Hole Oceanographic Institution
RP WETZEL, LR (corresponding author), WASHINGTON UNIV,DEPT EARTH & PLANETARY SCI,ST LOUIS,MO 63130, USA.
NR 34
TC 48
Z9 50
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 235
EP 237
DI 10.1038/362235a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600052
DA 2026-03-10
ER

PT J
AU ORCI, L
   PALMER, DJ
   RAVAZZOLA, M
   PERRELET, A
   AMHERDT, M
   ROTHMAN, JE
AF ORCI, L
   PALMER, DJ
   RAVAZZOLA, M
   PERRELET, A
   AMHERDT, M
   ROTHMAN, JE
TI BUDDING FROM GOLGI MEMBRANES REQUIRES THE COATOMER COMPLEX OF NON-CLATHRIN COAT PROTEINS
SO NATURE
LA English
DT Article
ID brefeldin-a; binding protein; beta-cop; transport; vesicles; stack; apparatus; cells; pits
AB DO the coats on vesicles budded from the Golgi apparatus actually cause the budding, or do they simply coat buds (Fig. 1)? One view (the membrane-mediated budding hypothesis1) is that budding is an intrinsic property of Golgi membranes not requiring extrinsic coat proteins. Assembly of coats from dispersed subunits is superimposed upon the intrinsic budding process and is proposed to convert the tips of tubules into vesicles. The alternative view (the coat-mediated budding hypothesis1) is that coat formation provides the essential driving force for budding. The membrane-mediated budding hypothesis was inspired by the microtubule-dependent extension of apparently uncoated, 90-nm-diameter membrane tubules from the Golgi apparatus2 and other organelles3-5 in vivo after treatment with brefeldin A, a drug that inhibits the assembly of coat proteins onto Golgi membranes6-9. This hypothesis predicts that tubules will be extended when coat proteins are unavailable to convert tubule-derived membrane into vesicles. Here we use a cell-free system in which coated vesicles are formed from Golgi cisternae to show that, on the contrary, when budding diminishes as a result of immunodepletion of coat protein pools, tubules are not formed at the expense of vesicles. We conclude that coat proteins are required for budding from Golgi membranes.
C1 SLOAN KETTERING INST CANC RES, PROGRAM CELLULAR BIOCHEM & BIOPHYS, NEW YORK, NY 10021 USA.
C3 Memorial Sloan Kettering Cancer Center
RP ORCI, L (corresponding author), UNIV GENEVA, SCH MED, INST HISTOL & EMBRYOL, 1 RUE MICHEL SERVET, CH-1211 GENEVA 4, SWITZERLAND.
NR 30
TC 150
Z9 163
U1 1
U2 14
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 648
EP 652
DI 10.1038/362648a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800054
PM 8464517
DA 2026-03-10
ER

PT J
AU ROSTEK, F
   RUHLAND, G
   BASSINOT, FC
   MULLER, PJ
   LABEYRIE, LD
   LANCELOT, Y
   BARD, E
AF ROSTEK, F
   RUHLAND, G
   BASSINOT, FC
   MULLER, PJ
   LABEYRIE, LD
   LANCELOT, Y
   BARD, E
TI RECONSTRUCTING SEA-SURFACE TEMPERATURE AND SALINITY USING DELTA-O-18 AND ALKENONE RECORDS
SO NATURE
LA English
DT Article
ID indian-ocean; circulation; monsoon
AB THE oxygen isotope (deltaO-18) composition of foraminiferal tests from deep-sea sediments is widely used as a palaeoclimate proxy, but it includes contributions from sea surface temperature, global ice volume and local salinity, which are difficult to separate. Recently a new technique for deriving palaeotemperatures has been developed which is based on the abundance ratios of unsaturated alkenones in phytoplankton algae1,2. Here we use a combination of oxygen isotope and alkenone records in a deep-sea core from the juncture of the Arabian Sea and the Bay of Bengal to extract the salinity signal from the former record. Variations in salinity are related to the balance between evaporation and precipitation3, and are thus a sensitive indicator of climate change. Our 170-kyr salinity record enables us to reconstruct changes in the Indian monsoon over this period, considerably extending  earlier studies (which reached back to 18 kyr ago)4-8. Like these previous studies, we find that large variations in the monsoon occurred during the transition from the last glacial period to the present interglacial, but our results also provide a view of the monsoon throughout the last glacial and demonstrate the potential of this approach for reconstructing palaeosalinity.
C1 UNIV BREMEN,FB GEOWISSENSCH,W-2800 BREMEN 33,GERMANY.
   UNIV AIX MARSEILLE 3,GEOSCI ENVIRONNEMENT LAB,F-13628 AIX EN PROVENCE,FRANCE.
   CEA,CNRS,CTR FAIBLES RADIOACT,F-91190 GIF SUR YVETTE,FRANCE.
C3 University of Bremen; Aix-Marseille Universite; Universite Paris Saclay; Centre National de la Recherche Scientifique (CNRS); CEA
RP ROSTEK, F (corresponding author), CNRS,GEOL QUATERNAIRE LAB,MARSEILLE,FRANCE.
NR 31
TC 238
Z9 259
U1 0
U2 89
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 319
EP 321
DI 10.1038/364319a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000051
DA 2026-03-10
ER

PT J
AU GODIN, IE
   GARCIAPORRERO, JA
   COUTINHO, A
   DIETERLENLIEVRE, F
   MARCOS, MAR
AF GODIN, IE
   GARCIAPORRERO, JA
   COUTINHO, A
   DIETERLENLIEVRE, F
   MARCOS, MAR
TI PARAAORTIC SPLANCHNOPLEURA FROM EARLY MOUSE EMBRYOS CONTAINS B1A CELL PROGENITORS
SO NATURE
LA English
DT Article
ID yolk-sac; b-cells; monoclonal-antibody; stem-cells; origin; lymphopoiesis; ontogeny; system; mice
AB DEFINITIVE erythropoiesis in birds originates from stem cells that emerge in the splanchnopleural mesoderm near the embryonic aorta1-4. The yolk sac is still generally held to be the unique provider of haematopoietic stem cells during mammalian ontogeny5, although there may be an alternative intraembryonic source of stem cells in the mouse fetus6,7. Here we search for a possible non-yolk-sac source of stem cells by grafting intraembryonic splanchnopleura from 10- to 18-somite mouse embryos into adult immunodeficient SCID mice. We find significant amounts of donor-derived serum IgM, normal numbers of IgM-secreting plasma cells, and the B1a (IgM(bright)(a)B220(dull)CD5+) cell subset to be fully reconstituted by donor progenitors 3 to 6 months after engraftment. The haematogenic capacity revealed in our experiments is present in a previously unrecognized site, the earliest described in the embryo, 12 hours before fetal liver colonization.
C1 COLL FRANCE, F-94130 NOGENT SUR MARNE, FRANCE.
   UNIV CANTABRIA, DEPT ANAT & CELL BIOL, E-39011 SANTANDER, SPAIN.
   INST PASTEUR, CNRS, UNITE IMMUNOBIOL 357, F-75724 PARIS 15, FRANCE.
   UNIV SALAMANCA, DEPT MED, E-37007 SALAMANCA, SPAIN.
C3 Universite PSL; College de France; Universidad de Cantabria; Centre National de la Recherche Scientifique (CNRS); Pasteur Network; Universite Paris Cite; Institut Pasteur Paris; University of Salamanca
RP GODIN, IE (corresponding author), CNRS, INST EMBRYOL CELLULAIRE, F-94130 NOGENT SUR MARNE, FRANCE.
NR 22
TC 325
Z9 376
U1 0
U2 3
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 67
EP 70
DI 10.1038/364067a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800059
PM 8316299
DA 2026-03-10
ER

PT J
AU JIAO, SS
   GUREVICH, V
   WOLFF, JA
AF JIAO, SS
   GUREVICH, V
   WOLFF, JA
TI RETRACTED: LONG-TERM CORRECTION OF RAT MODEL OF PARKINSONS-DISEASE BY GENE-THERAPY (Retracted Article)
SO NATURE
LA English
DT Article; Retracted Publication
ID performance liquid-chromatography; genetically engineered cells; produce l-dopa; brain; catecholamines; grafts; skin
AB THE implantation of cells genetically modified to express tyrosine hydroxylase has been proposed for the treatment of Parkinson's disease1. Tyrosine hydroxylase converts tyrosine to L-DOPA and endogenous decarboxylase activity then converts L-DOPA to the neurotransmitter dopamine, which alleviates the symptoms of Parkinson's disease. Immortalized cells have been successfully used as intracerebral vehicles for transgene expression of tyrosine hydroxylase, but the tumorigenic potential of these cells prevents their application in humans1-4. Intracerebral expression of this enzyme has also been achieved using primary cells like skin fibroblasts5-7, but the ameliorating effect on a rat model for Parkinson's disease lasted for only a few weeks. We have found that co-transplantation of cultured myoblasts and myotubes enabled reporter genes to be expressed intracerebrally at high and stable levels8-10. Here we show that the intracerebral transplantation of plasmid-transfected primary muscle cells can substantially reduce for the long-term the asymmetric rotational behaviour in the rat model.
C1 UNIV WISCONSIN, WAISMAN CTR, DEPT PEDIAT, MADISON, WI 53705 USA.
   UNIV WISCONSIN, WAISMAN CTR, DEPT MED GENET, MADISON, WI 53705 USA.
C3 University of Wisconsin System; University of Wisconsin Madison; University of Wisconsin System; University of Wisconsin Madison
NR 24
TC 150
Z9 189
U1 0
U2 12
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 450
EP 453
DI 10.1038/362450a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400084
PM 8096625
DA 2026-03-10
ER

PT J
AU GERSTEIN, RM
   LIEBER, MR
AF GERSTEIN, RM
   LIEBER, MR
TI EXTENT TO WHICH HOMOLOGY CAN CONSTRAIN CODING EXON JUNCTIONAL DIVERSITY IN V(D)J RECOMBINATION
SO NATURE
LA English
DT Article
ID streptococcus-pneumoniae; gene rearrangement; joining signals; immune-system; antibody; phosphorylcholine; phosphocholine; cell; insertion; sequences
AB AMONG site-directed DNA recombination systems, V(D)J recombination is noteworthy in that identical reactants yield different recombination products at the junction of joined segments. This variation is the basis for diversity at the base of antigen receptor binding pockets and corresponds to V-(D)-J DNA junctions. An abundance of certain junctions has been noted1-5. It has been proposed that these junctions are favoured because they occur where short regions of homology in participating coding ends might align preferentially1. Here we use a system that is entirely free from cellular selection to show that the diversity of coding joints can be severely restricted when the coding ends participating in the reaction have short regions of homology. This constraint on diversity is diminished but not eliminated by terminal deoxynucleotidyl transferase, a mechanistic feature that has implications for the establishment of the immune repertoire.
C1 STANFORD UNIV,MED CTR,SCH MED,DEPT PATHOL,EXPTL ONCOL LAB,STANFORD,CA 94305.
C3 Stanford University
NR 29
TC 100
Z9 103
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 625
EP 627
DI 10.1038/363625a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900055
PM 8510753
DA 2026-03-10
ER

PT J
AU FENIMORE, EE
   EPSTEIN, RI
   HO, C
   KLEBESADEL, RW
   LACEY, C
   LAROS, JG
   MEIER, M
   STROHMAYER, T
   PENDLETON, G
   FISHMAN, G
   KOUVELIOTOU, C
   MEEGAN, C
AF FENIMORE, EE
   EPSTEIN, RI
   HO, C
   KLEBESADEL, RW
   LACEY, C
   LAROS, JG
   MEIER, M
   STROHMAYER, T
   PENDLETON, G
   FISHMAN, G
   KOUVELIOTOU, C
   MEEGAN, C
TI THE INTRINSIC LUMINOSITY OF GAMMA-RAY BURSTS AND THEIR HOST GALAXIES
SO NATURE
LA English
DT Article
ID evolution; models
AB THE Burst and Transient Source Experiment (BATSE) on the Compton Gamma-Ray Observatory has shown that, although gamma-ray bursts are distributed isotropically on the sky, there is an apparent dearth of weak events compared to those expected from a homogeneous distribution of sources1,2. This suggests that the bursts originate either in an extended galactic halo3 (that is, locally) or at cosmological distances4,5. The intensity distribution of the bursts can be used to constrain their source properties and spatial distribution, and here we address this question by considering the BATSE data with those from the Pioneer Venus Orbiter, correcting for the different reponse of the two instruments. We show that the composite intensity distribution can after all be fitted by a simple, homogeneous model of gamma-ray burst sources with identical intrinsic luminosities where the faintest BATSE events are at a redshift of z approximately 0.80+/-0.05. We obtain an upper limit of about -18 on the absolute magnitude of the host galaxies by assigning model-derived distances to the brightest extragalactic objects found15 within the error boxes of eight well localized gamma-ray bursts. All but the faintest active galaxies are excluded as the source of the bursts. The bursts may instead be associated with normal galaxies, but only if the host-galaxy magnitudes are close to our upper limit.
C1 NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,HUNTSVILLE,AL 35812.
C3 National Aeronautics & Space Administration (NASA); NASA Marshall Space Flight Center
RP FENIMORE, EE (corresponding author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA.
NR 22
TC 153
Z9 158
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 40
EP 42
DI 10.1038/366040a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700046
DA 2026-03-10
ER

PT J
AU LAWSON, CL
AF LAWSON, CL
TI TANDEM BINDING IN CRYSTALS OF A TRP REPRESSOR-OPERATOR HALF-SITE COMPLEX
SO NATURE
LA English
DT Article
ID escherichia-coli; dna; crystallography; detector
AB THE crystal structure of trp repressor tandemly bound in a 2:1 complex to a 16-base-pair palindromic DNA containing a central trp operator half-site has been determined and refined to 2.4 angstrom resolution. Despite dramatically different DNA sequence contexts and crystallization conditions, the protein/DNA interface is essentially identical to that seen in the original trp repressor/operator complex structure1. Water-mediated sequence recognition by trp repressor is likely to be related to the unusual end-on approach of the recognition helix (E), which allows sharing of the major groove by tandem dimers. The tandem complex model accounts for the mutational sensitivity of all trp operator base pairs. The structure also provides the first detailed view of the tandem interaction, revealing a key role for the amino-terminal arms.
C1 PRINCETON UNIV,DEPT CHEM,PRINCETON,NJ 08544.
C3 Princeton University
RP LAWSON, CL (corresponding author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA.
NR 29
TC 152
Z9 160
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 178
EP 182
DI 10.1038/366178a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600064
PM 8232559
DA 2026-03-10
ER

PT J
AU MUNRO, S
   THOMAS, KL
   ABUSHAAR, M
AF MUNRO, S
   THOMAS, KL
   ABUSHAAR, M
TI MOLECULAR CHARACTERIZATION OF A PERIPHERAL RECEPTOR FOR CANNABINOIDS
SO NATURE
LA English
DT Article
ID rat-brain; insitu hybridization; cloning; invitro; cdna
AB THE major active ingredient of marijuana, DELTA9-tetrahydrocannabinol (DELTA9-THC), has been used as a psychoactive agent for thousands of years. Marijuana, and DELTA9-THC, also exert a wide range of other effects including analgesia, anti-inflammation, immunosuppression, anticonvulsion, alleviation of intraocular pressure in glaucoma, and attenuation of vomiting1. The clinical application of cannabinoids has, however, been limited by their psychoactive effects, and this has led to interest in the biochemical bases of their action. Progress stemmed initially from the synthesis of potent derivatives of DELTA9-THC4,5, and more recently from the cloning of a gene encoding a G-protein-coupled receptor for cannabinoids6. This receptor is expressed in the brain but not in the periphery, except for a low level in testes.  It has been proposed that the non-psychoactive effects of cannabinoids are either mediated centrally or through direct interaction with other, non-receptor proteins1,7,8. Here we report the cloning of a receptor for cannabinoids that is not expressed in the brain but rather in macrophages in the marginal zone of spleen.
RP MUNRO, S (corresponding author), MRC,MOLEC BIOL LAB,HILLS RD,CAMBRIDGE CB2 2QH,ENGLAND.
NR 34
TC 4158
Z9 4894
U1 2
U2 267
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 61
EP 65
DI 10.1038/365061a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600054
PM 7689702
DA 2026-03-10
ER

PT J
AU LINDE, AT
   AGUSTSSON, K
   SACKS, IS
   STEFANSSON, R
AF LINDE, AT
   AGUSTSSON, K
   SACKS, IS
   STEFANSSON, R
TI MECHANISM OF THE 1991 ERUPTION OF HEKLA FROM CONTINUOUS BOREHOLE STRAIN MONITORING
SO NATURE
LA English
DT Article
ID global positioning system; japan
AB VOLCANOES erupt when the pressure in a magma chamber several kilometres below the edifice overcomes the strength of the intervening rock. Seismic activity may accompany and precede eruptions, allowing (in favourable circumstances) the location and movement of magma to be traced. Ground deformation near volcanoes can provide more direct evidence for magma movement, but continuous monitoring is necessary to ensure that all the essential aspects of an eruption are recorded. Here we report dilatational strain data collected continuously during the January 1991 eruption of Hekla volcano by five borehole strainmeters located 15-45 km from the volcano. The data record the upward propagation of magma, as well as the deflation of a deep reservoir. In only 30. minutes the magma forced open a conduit to the surface from a depth of approximately 4 km. Although other volcanoes might behave differently, our results suggest the possibility of using continuous deformation measurements to monitor conduit formation at other sites, perhaps providing short-term warnings of impending eruptions.
C1 ICELAND METEOROL OFF,IS-150 REYKJAVIK,ICELAND.
RP LINDE, AT (corresponding author), CARNEGIE INST WASHINGTON,DEPT TERR MAGNETISM,5241 BROAD BRANCH RD NW,WASHINGTON,DC 20015, USA.
NR 15
TC 115
Z9 125
U1 0
U2 14
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 737
EP 740
DI 10.1038/365737a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200057
DA 2026-03-10
ER

PT J
AU EGAN, SE
   GIDDINGS, BW
   BROOKS, MW
   BUDAY, L
   SIZELAND, AM
   WEINBERG, RA
AF EGAN, SE
   GIDDINGS, BW
   BROOKS, MW
   BUDAY, L
   SIZELAND, AM
   WEINBERG, RA
TI ASSOCIATION OF SOS RAS EXCHANGE PROTEIN WITH GRB2 IS IMPLICATED IN TYROSINE KINASE SIGNAL TRANSDUCTION AND TRANSFORMATION
SO NATURE
LA English
DT Article
ID elegans vulvar induction; gene-transfer; oncogene; receptor; sevenless; encodes; drosophila; pathway; domain; let-60
AB The proteins Grb2-Sem-5, Shc and Sos have been implicated in the signalling pathway from tyrosine kinase receptors to Ras. Grb2-Sem-5 binds directly to murine Sos1, a Ras exchange factor, through two SH3 domains. Sos is also associated with ligand-activated tyrosine kinase receptors which bind Grb2-Sem-5, and with the Grb2-Sem-5 binding protein, Shc. Ectopic expression of Drosophila Sos stimulates morphological transformation of rodent fibroblasts. These data define a pathway by which tyrosine kinases act through Ras to control cell growth and differentiation.
C1 MIT,WHITEHEAD INST BIOMED RES,9 CAMBRIDGE CTR,CAMBRIDGE,MA 02142.
   MIT,DEPT BIOL,CAMBRIDGE,MA 02142.
   IMPERIAL CANC RES FUND,LONDON WC2A 3PX,ENGLAND.
C3 Massachusetts Institute of Technology (MIT); Whitehead Institute; Massachusetts Institute of Technology (MIT); Cancer Research UK
NR 46
TC 1197
Z9 1343
U1 1
U2 50
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 45
EP 51
DI 10.1038/363045a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200051
PM 8479536
DA 2026-03-10
ER

PT J
AU MCKIM, KS
   JANG, JK
   THEURKAUF, WE
   HAWLEY, RS
AF MCKIM, KS
   JANG, JK
   THEURKAUF, WE
   HAWLEY, RS
TI MECHANICAL BASIS OF MEIOTIC METAPHASE ARREST
SO NATURE
LA English
DT Article
ID drosophila-melanogaster; segregation
AB CONTROL of the metaphase to anaphase transition is a central component of cell-cycle regulation. Arrest at either metaphase I or II before fertilization is a common component of oogenesis in many organisms1. In Drosophila melanogaster females, this arrest occurs at meiosis I with the chiasmate bivalents tightly massed at the metaphase plate and the nonexchange chromosomes positioned between the plate and the poles on long tapered spindles2.  Meiosis resumes only after passage through the oviduct 3,4. Thus, metaphase arrest defines an important checkpoint in the meiotic cell cycle'. We report here that this arrest results from the balancing of chiasmate bivalents at the metaphase plate. Two meiotic mutations, mei-9b and mei-218a4, both of which greatly reduce the frequency of chiasma formation, bypass the metaphase block and allow stage 14 oocytes to finish both meiotic divisions without arrest. We conclude that metaphase arrest results from the balancing of kinetochore forces due to chiasmata.
C1 UNIV CALIF DAVIS,DEPT GENET,DAVIS,CA 95616.
   SUNY STONY BROOK,DEPT BIOCHEM & CELL BIOL,STONY BROOK,NY 11794.
C3 University of California System; University of California Davis; State University of New York (SUNY) System; Stony Brook University
NR 14
TC 73
Z9 84
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 364
EP 366
DI 10.1038/362364a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600068
PM 8455723
DA 2026-03-10
ER

PT J
AU SVERJENSKY, DA
AF SVERJENSKY, DA
TI PHYSICAL SURFACE-COMPLEXATION MODELS FOR SORPTION AT THE MINERAL-WATER INTERFACE
SO NATURE
LA English
DT Article
ID high-pressures; metal-ions; adsorption; temperatures; equation; solids; state
AB NONE of the traditional models of surface complexation of ions at oxide-water interfaces, such as the constant-capacitance, double-diffuse-layer and triple-layer models1-5, provides an explicit, quantitative treatment of ion solvation. Here I show that this process can be included quantitatively in surface-complexation theory by describing it using the Born theory of ion solvation6,7. In this way, the standard Gibbs free energy of sorption can be decomposed into three terms: the standard coulombic term, a Born solvation contribution and a term intrinsic to the ion alone. Consideration of the Born solvation term shows that the equilibrium constant for sorption depends linearly on the inverse of the dielectric constant of the solid. By this means, all three contributions to the free energy can be estimated empirically or calculated theoretically. Inclusion of this physical description of ion solvation should facilitate the application of the theory of ion sorption to complex natural oxide and silicate minerals.
RP SVERJENSKY, DA (corresponding author), JOHNS HOPKINS UNIV,DEPT EARTH & PLANETARY SCI,BALTIMORE,MD 21218, USA.
NR 19
TC 105
Z9 117
U1 1
U2 62
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 776
EP 780
DI 10.1038/364776a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100047
DA 2026-03-10
ER

PT J
AU HEYDUK, T
   LEE, JC
   EBRIGHT, YW
   BLATTER, EE
   ZHOU, YH
   EBRIGHT, RH
AF HEYDUK, T
   LEE, JC
   EBRIGHT, YW
   BLATTER, EE
   ZHOU, YH
   EBRIGHT, RH
TI CAP INTERACTS WITH RNA-POLYMERASE IN SOLUTION IN THE ABSENCE OF PROMOTER DNA
SO NATURE
LA English
DT Article
ID amp receptor protein; escherichia-coli; transcription factor; lac promoter; fluorescence polarization; ribosomal-subunits; binding; activator; mutants; region
AB PROTEIN-PROTEIN interactions between transcription activator proteins and RNA polymerase or basal transcription factors have been suggested to be important for transcription activation1-8. Interactions between catabolite gene activator protein (CAP)9,10 and RNA polymerase have been proposed based on face-of-helix-dependent transcription activation by CAP11-13 and based on face-of-helix-dependent cooperative binding of CAP and RNA polymerase to promoter DNA14,15. Mutants of CAP specifically defective in transcription activation have been isolated (mutants defective in transcription activation, but not defective in DNA binding and DNA bending16-19). All such mutants contain amino-acid substitutions within a surface loop consisting of amino acids 152 to 166 of CAP16-19. Here we use the thermodynamically rigorous technique of fluorescence polarization20-23 to show that CAP interacts with RNA polymerase in solution in the absence of promoter DNA (K(D,app) = 2.8 x 10(-7) M), whereas [Ala158]CAP, a mutant of CAP specifically defective in transcription activation, does not.
C1 RUTGERS UNIV,DEPT CHEM,NEW BRUNSWICK,NJ 08855.
   RUTGERS UNIV,WAKSMAN INST,NEW BRUNSWICK,NJ 08855.
   UNIV TEXAS,MED BRANCH,DEPT HUMAN BIOL CHEM & GENET,GALVESTON,TX 77550.
C3 Rutgers University System; Rutgers University New Brunswick; Rutgers University System; Rutgers University New Brunswick; University of Texas System; University of Texas Medical Branch Galveston
NR 30
TC 77
Z9 82
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 548
EP 549
DI 10.1038/364548a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700061
PM 8393148
DA 2026-03-10
ER

PT J
AU DETOLEDO, GA
   FERNANDEZCHACON, R
   FERNANDEZ, JM
AF DETOLEDO, GA
   FERNANDEZCHACON, R
   FERNANDEZ, JM
TI RELEASE OF SECRETORY PRODUCTS DURING TRANSIENT VESICLE FUSION
SO NATURE
LA English
DT Article
ID nuclear magnetic-resonance; mouse mast-cells; capacitance measurements; chromaffin cells; exocytosis; granules; voltammetry; invitro; matrix; pore
AB PATCH-CLAMP experiments have shown that fusion of secretory granules with the plasma membrane does not always occur as an all-or-none event, but can develop slowly in a fluctuating manner or can be transient1-5. These observations suggested that release could be detected during such incomplete fusion events. To test this hypothesis we have combined patch-clamp measurements of the activity of single exocytotic fusion pores in beige mouse mast cells with the electrochemical detection of serotonin released during the exocytotic events. We report here that on fusion pore opening there is a small release of serotonin which is directly proportional to the pore conductance. We also show that a significant release occurs during transient fusion events. These results demonstrate, to our knowledge for the first time, release of a neurotransmitter from a secretory vesicle that did not undergo complete fusion.
C1 MAYO CLIN & MAYO FDN,DEPT PHYSIOL & BIOPHYS,ROCHESTER,MN 55905.
C3 Mayo Clinic
RP DETOLEDO, GA (corresponding author), UNIV SEVILLA,FAC MED,DEPT FISIOL MED & BIOFIS,AVDA SANCHEZ PIZJUAN 4,E-41009 SEVILLE,SPAIN.
NR 21
TC 508
Z9 558
U1 0
U2 34
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 554
EP 558
DI 10.1038/363554a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900054
PM 8505984
DA 2026-03-10
ER

PT J
AU GOULDING, EH
   TIBBS, GR
   LIU, D
   SIEGELBAUM, SA
AF GOULDING, EH
   TIBBS, GR
   LIU, D
   SIEGELBAUM, SA
TI ROLE OF H5 DOMAIN IN DETERMINING PORE DIAMETER AND ION PERMEATION THROUGH CYCLIC NUCLEOTIDE-GATED CHANNELS
SO NATURE
LA English
DT Article
ID k+ channel; tea blockade; charybdotoxin; inhibitor; receptor; region; muscle; site
AB ION permeation through membrane channels is thought to be governed by a narrow region of the channel pore termed the selectivity filter1, which has been proposed to discriminate among ions by both specific binding and molecular sieving, as determined by pore diameter. Recent evidence suggests that a conserved domain (known as H5, P or SS1-SS2) in voltage-gated potassium2-8, sodium9-13 and calcium12channels contributes to the lining of the pore. Here we investigate whether the H5 domain determines pore diameter and examine the role of pore diameter in controlling ion permeation. These studies rely on differences in single channel conductance, ion selectivity and apparent pore diameter between cyclic nucleotide-gated channels cloned from bovine retina14 and catfish olfactory neurons15. Using chimaeric retinal-olfactory channels, we find that the H5 domain determines these differences in permeation properties, providing structural evidence that the cyclic nucleotide-gated channels are indeed members of the voltage-gated channel family15-17. Moreover, these results show directly that the H5 domain helps form the selectivity filter and that molecular sieving is important in controlling ion permeation.
C1 COLUMBIA UNIV,DEPT PHARMACOL,NEW YORK,NY 10032.
   COLUMBIA UNIV,HOWARD HUGHES MED INST,NEW YORK,NY 10032.
C3 Columbia University; Columbia University; Howard Hughes Medical Institute
RP GOULDING, EH (corresponding author), COLUMBIA UNIV,DEPT PHYSIOL,CTR NEUROBIOL & BEHAV,722 W 168 ST,NEW YORK,NY 10032, USA.
NR 22
TC 110
Z9 113
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 61
EP 64
DI 10.1038/364061a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800057
PM 7686276
DA 2026-03-10
ER

PT J
AU MASSUNG, RF
   ESPOSITO, JJ
   LIU, LI
   QI, J
   UTTERBACK, TR
   KNIGHT, JC
   AUBIN, L
   YURAN, TE
   PARSONS, JM
   LOPAREV, VN
   SELIVANOV, NA
   CAVALLARO, KF
   KERLAVAGE, AR
   MAHY, BWJ
   VENTER, JC
AF MASSUNG, RF
   ESPOSITO, JJ
   LIU, LI
   QI, J
   UTTERBACK, TR
   KNIGHT, JC
   AUBIN, L
   YURAN, TE
   PARSONS, JM
   LOPAREV, VN
   SELIVANOV, NA
   CAVALLARO, KF
   KERLAVAGE, AR
   MAHY, BWJ
   VENTER, JC
TI POTENTIAL VIRULENCE DETERMINANTS IN TERMINAL REGIONS OF VARIOLA SMALLPOX VIRUS GENOME
SO NATURE
LA English
DT Article
AB SMALLPox eradication culminated the most successful antimicrobial campaign in medical history1. To characterize further the linear double-stranded DNA genome of the aetiological agent of smallpox, we have determined the entire nucleotide sequence of the highly virulent variola major virus, strain Bangladesh-1975 (VA R-BSH; 186,102 base pairs, 33.7% G + C; Genbank accession number, L22579). Here we highlight features of the molecule and focus on a few of the 187 putative proteins that probably contribute to pathogenicity and virus host-range properties. One hundred and fifty proteins were markedly similar to those of vaccinia virus (smallpox vaccine), for which a complete sequence has been reported2,3 for strain Copenhagen (VAC-CPN; 191,636 base pairs, 33.3% G + C). The remaining 37 proteins reflected variola-specific sequences or open reading frame divergences for variant proteins, which are often truncated or elongated compared with their vaccinia counterparts.
C1 CTR DIS CONTROL & PREVENT, NATL CTR INFECT DIS, DIV VIRAL & RICKETTSIAL DIS, ATLANTA, GA 30333 USA.
   NINCDS, BETHESDA, MD 20892 USA.
   INST GENOM RES, GAITHERSBURG, MD 20878 USA.
C3 Centers for Disease Control & Prevention - USA; National Center for Infectious Diseases (NCID); National Institutes of Health (NIH) - USA; NIH National Institute of Neurological Disorders & Stroke (NINDS); J. Craig Venter Institute
NR 27
TC 154
Z9 398
U1 0
U2 13
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 23
PY 1993
VL 366
IS 6457
BP 748
EP 751
DI 10.1038/366748a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MN264
UT WOS:A1993MN26400030
PM 8264798
DA 2026-03-10
ER

PT J
AU CASANOVA, J
   STRUHL, G
AF CASANOVA, J
   STRUHL, G
TI THE TORSO RECEPTOR LOCALIZES AS WELL AS TRANSDUCES THE SPATIAL SIGNAL SPECIFYING TERMINAL BODY PATTERN IN DROSOPHILA
SO NATURE
LA English
DT Article
ID tyrosine kinase; vulvar induction; gene torso; embryo; expression; mutations; elements; anlagen; encodes; let-23
AB SPECIFICATION of the end portions of the Drosophila body depends on the torso (tor) protein, a receptor tyrosine kinase that accumulates uniformly along the entire surface of the embryo but is activated only in the vicinity of the poles1-6. Several genes are normally required for activating tor and appear to define a system in which a gene product tethered to the extracellular vitelline membrane at each end of the egg provides a local source for an extracellular tor ligand2,5-7. This ligand would have to diffuse from the membrane to the cell surface of the embryo without losing its spatial localization. Here we report that the failure to accumulate tor protein at one or both poles leads to spatially inappropriate activity of more centrally located receptor. This ectopic activity depends on the same gene functions normally required for activating tor; thus we infer that it reflects inappropriate diffusion of the ligand to more central regions of the body. We conclude that the receptor not only transduces the spatial signal imparted by the tor ligand, but also ensures its correct localization by sequestering the ligand. Ligand trapping by receptor, may also localize spatial signals in other patterning systems, including specification of the dorsal-ventral axis in Drosophila and of vulval cell fates in Caenorhabditis elegans.
C1 CSIC,CTR INVESTIGACIO & DESENVOLUPAMENT,E-08034 BARCELONA,SPAIN.
C3 Consejo Superior de Investigaciones Cientificas (CSIC)
RP CASANOVA, J (corresponding author), COLUMBIA UNIV COLL PHYS & SURG,HOWARD HUGHES MED INST,701 W 168TH ST,NEW YORK,NY 10032, USA.
NR 17
TC 83
Z9 92
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 152
EP 155
DI 10.1038/362152a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800058
PM 8450886
DA 2026-03-10
ER

PT J
AU LEHMAN, N
   JOYCE, GF
AF LEHMAN, N
   JOYCE, GF
TI EVOLUTION INVITRO OF AN RNA ENZYME WITH ALTERED METAL DEPENDENCE
SO NATURE
LA English
DT Article
ID group-i introns; secondary structure; catalytic rna; active-site; tetrahymena; requirements; amplification; ribozyme
AB THE Tetrahymena group I ribozyme catalyses a sequence-specific phosphodiester cleavage reaction on an external RNA oligonucleotide substrate in the presence of a divalent metal cation cofactor1. This reaction proceeds readily with either Mg2+ or Mn2+, but no detectable reaction has been reported when other divalent cations are used as the sole cofactor2-5. Cations such as Ca2+, Sr2+ and Ba2+ can stabilize the correct folded conformation of the ribozyme, thereby partially alleviating the Mg2+ or Mn2+ requirement2. But catalysis by the ribozyme involves coordination of either Mg2+ or Mn2+ at the active site, resulting in an overall requirement for one of these two cations5. Here we use an in vitro evolution process6,7 to obtain variants of the Tetrahymena ribozyme that are capable of cleaving an RNA substrate in reaction mixtures containing Ca2+ as the divalent cation. These findings extend the range of different chemical environments available to RNA enzymes and illustrate the power of in vitro evolution in generating macromolecular catalysts with desired properties.
C1 SCRIPPS RES INST, DEPT MOLEC BIOL, LA JOLLA, CA 92037 USA.
C3 Scripps Research Institute
RP LEHMAN, N (corresponding author), SCRIPPS RES INST, DEPT CHEM, 10666 N TORREY PINES RD, LA JOLLA, CA 92037 USA.
NR 22
TC 168
Z9 202
U1 1
U2 17
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 182
EP 185
DI 10.1038/361182a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600069
PM 8421526
DA 2026-03-10
ER

PT J
AU OECHEL, WC
   HASTINGS, SJ
   VOURLITIS, G
   JENKINS, M
   RIECHERS, G
   GRULKE, N
AF OECHEL, WC
   HASTINGS, SJ
   VOURLITIS, G
   JENKINS, M
   RIECHERS, G
   GRULKE, N
TI RECENT CHANGE OF ARCTIC TUNDRA ECOSYSTEMS FROM A NET CARBON-DIOXIDE SINK TO A SOURCE
SO NATURE
LA English
DT Article
ID temperature; climate; trends; peat; co2
AB ARCTIC tundra has been a net sink for carbon dioxide during historic and recent geological times1-4, and large amounts of carbon are stored in the soils of northern ecosystems. Many regions of the Arctic are warmer now than they have been in the past5-10, and this warming may cause the soil to change from a carbon dioxide sink to a source by lowering the water table11,12, thereby accelerating the rate of soil decomposition (CO2 source)3,13-15 so that this dominates over photosynthesis (CO2 sink). Here we present data indicating that the tundra on the North Slope of Alaska has indeed become a source of carbon dioxide to the atmosphere. This change coincides with recent warming in the Arctic, whether this is due to increases in greenhouse gas concentrations in the atmosphere or to some other cause. Our results suggest that tundra ecosystems may exert a positive feedback on atmospheric carbon dioxide and greenhouse warming.
C1 SAN DIEGO STATE UNIV,DEPT BIOL,SAN DIEGO,CA 92182.
   UNIV CALIF RIVERSIDE,STATEWIDE AIR POLLUT RES CTR,RIVERSIDE,CA 92521.
   US FOREST SERV,CORVALLIS,OR 97331.
C3 California State University System; San Diego State University; University of California System; University of California Riverside; United States Department of Agriculture (USDA); United States Forest Service
RP OECHEL, WC (corresponding author), SAN DIEGO STATE UNIV,SYST ECOL RES GRP,SAN DIEGO,CA 92182, USA.
NR 36
TC 712
Z9 825
U1 2
U2 234
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 520
EP 523
DI 10.1038/361520a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400054
DA 2026-03-10
ER

PT J
AU PAGEL, M
AF PAGEL, M
TI HONEST SIGNALING AMONG GAMETES
SO NATURE
LA English
DT Article
ID saccharomyces-cerevisiae; a-factor; alpha-factor; yeast; courtship; selection; induction; partners; gene
AB THE gametes of many lower eukaryotic organisms emit pheromones that attract gametes of the opposite mating type or sex1-4. Gametes move or grow in the direction of the highest pheromone concentration, suggesting that the strength of the pheromonal signal is used to infer proximity, or that the strongest signal is most likely to be noticed. Here I offer a new explanation of pheromonal signalling and chemotaxis in gametes. I show that pheromonal signals can be interpreted as sexually selected traits that honestly advertise variation in quality among gametes, given that signals are costly to produce and that gametes compete; by 'quality' I refer to some aspect of a gamete's fitness. A gamete's preference for a mating partner, then, is predicted to vary with the quality of a prospective partner as inferred from the strength of its signal. This view can explain characteristics of the signalling and mate selection behaviours of gametes that are not predicted by models of mate choice based on proximity or 'passive attraction' to the strongest signal5. These include repeated partner exchanges2, escalated exchanges of mating pheromones6-9, and rejection of gametes that signal at low levels8,9.
RP PAGEL, M (corresponding author), UNIV LONDON, QUEEN MARY & WESTFIELD COLL, SCH MATH SCI, LONDON E1 4NS, ENGLAND.
NR 23
TC 30
Z9 33
U1 0
U2 8
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 539
EP 541
DI 10.1038/363539a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900048
PM 8505979
DA 2026-03-10
ER

PT J
AU HONEA, EC
   OGURA, A
   MURRAY, CA
   RAGHAVACHARI, K
   SPRENGER, WO
   JARROLD, MF
   BROWN, WL
AF HONEA, EC
   OGURA, A
   MURRAY, CA
   RAGHAVACHARI, K
   SPRENGER, WO
   JARROLD, MF
   BROWN, WL
TI RAMAN-SPECTRA OF SIZE-SELECTED SILICON CLUSTERS AND COMPARISON WITH CALCULATED STRUCTURES
SO NATURE
LA English
DT Article
ID attenuated-total-reflection; equilibrium structures; photoelectron-spectra; electronic-structures; scattering; metals
AB SMALL clusters of silicon, containing between 2 and 100 atoms, have been studied extensively both because of their intrinsic interest from the point of view of chemical structure and bonding and because of the potential technological applications of cluster-assembled materials1-3. Ab initio quantum-chemical calculations predict that very small clusters should have structures markedly different from that of the crystalline phase4-12. Experiments on two- (ref. 13), three- (ref. 14) and four-atom15 clusters have allowed some comparison with theoretical predictions, but structural information on larger clusters has been only indirect16. Here we report on structural studies of size-selected Si4, Si6 and Si7 clusters prepared and isolated by low-energy deposition into a solid nitrogen matrix. Surface plasmon-polariton enhanced Raman spectroscopy17-20 yields well resolved vibrational spectra for each of these clusters in which the vibrational frequencies agree well with those predicted for optimized structures calculated by ab initio methods. We confirm that Si4 is a planar rhombus, and find that Si6 is a distorted octahedron and Si7 a pentagonal bipyramid.
C1 NORTHWESTERN UNIV, DEPT CHEM, EVANSTON, IL 60208 USA.
   NEC CORP LTD, MICROELECTR RES LABS, TSUKUBA, JAPAN.
C3 Northwestern University; NEC Corporation
RP HONEA, EC (corresponding author), AT&T BELL LABS, MURRAY HILL, NJ 07974 USA.
NR 30
TC 381
Z9 393
U1 0
U2 98
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 42
EP 44
DI 10.1038/366042a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700047
DA 2026-03-10
ER

PT J
AU NAKATSU, Y
   TYNDALE, RF
   DELOREY, TM
   DURHAMPIERRE, D
   GARDNER, JM
   MCDANEL, HJ
   NGUYEN, Q
   WAGSTAFF, J
   LALANDE, M
   SIKELA, JM
   OLSEN, RW
   TOBIN, AJ
   BRILLIANT, MH
AF NAKATSU, Y
   TYNDALE, RF
   DELOREY, TM
   DURHAMPIERRE, D
   GARDNER, JM
   MCDANEL, HJ
   NGUYEN, Q
   WAGSTAFF, J
   LALANDE, M
   SIKELA, JM
   OLSEN, RW
   TOBIN, AJ
   BRILLIANT, MH
TI A CLUSTER OF 3 GABA(A) RECEPTOR SUBUNIT GENES IS DELETED IN A NEUROLOGICAL MUTANT OF THE MOUSE P-LOCUS
SO NATURE
LA English
DT Article
ID prader-willi syndrome; angelman syndrm; region; localization; benzodiazepine; chromosome-7; expression; beta-3; alpha; model
AB THE mouse pink-eyed cleft-palate (p(cp)) mutation is characterized by hypopigmentation associated with cleft palate, neurological disorders and runting1,2. Most p(cp) homozygotes are born with cleft palate and die shortly after birth, presumably as a result of feeding problems3. A few exceptional p(cp) mutants live beyond this stage but display tremor and jerky gait2. We report here that the genes encoding the gamma-aminobutyric acid type A (GABA(A)) receptor subunits alpha5 (originally described as alpha4; ref. 4), beta3 and gamma3 are disrupted by a deletion in p(cp) mice. We also show that the alpha5 and gamma3 genes are located between the p and beta3 genes on mouse chromosome 7. The p(cp) deletion leads to alterations of binding properties of the GABA(A) receptors in the brain, providing an in vivo model system for studying GABA(A) receptor function. The human homologue of the region deleted in p(cp) mice is associated with Angelman syndrome5-9. Thus, p(cp) mice may be useful in defining the region containing the gene(s) for this syndrome.
C1 FOX CHASE CANC CTR,INST CANC RES,7701 BURHOLME AVE,PHILADELPHIA,PA 19111.
   UNIV CALIF LOS ANGELES,SCH MED,DEPT PHARMACOL,LOS ANGELES,CA 90024.
   UNIV CALIF LOS ANGELES,DEPT BIOL,LOS ANGELES,CA 90024.
   CHILDRENS HOSP MED CTR,DIV GENET,BOSTON,MA 02115.
   HARVARD UNIV,SCH MED,DEPT PEDIAT,BOSTON,MA 02115.
   HOWARD HUGHES MED INST,BOSTON,MA 02115.
   UNIV COLORADO,HLTH SCI CTR,DEPT PHARMACOL,DENVER,CO 80262.
C3 Fox Chase Cancer Center; University of California System; University of California Los Angeles; University of California Los Angeles Medical Center; David Geffen School of Medicine at UCLA; University of California System; University of California Los Angeles; Harvard University; Harvard University Medical Affiliates; Boston Children's Hospital; Harvard University; Harvard Medical School; Howard Hughes Medical Institute; University of Colorado System; University of Colorado Anschutz Medical Campus; University of Colorado Denver
NR 32
TC 94
Z9 98
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 448
EP 450
DI 10.1038/364448a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000056
PM 8392662
DA 2026-03-10
ER

PT J
AU CHYBA, CF
AF CHYBA, CF
TI EXPLOSIONS OF SMALL SPACEWATCH OBJECTS IN THE EARTHS ATMOSPHERE
SO NATURE
LA English
DT Article
AB RECENT observations with the Spacewatch telescope indicate that the flux of Earth-crossing objects with diameters below about 50 m is some 10-100 times higher than predicted by simple extrapolation from the known main-belt asteroid population1,2. This might seem to imply3 a significantly greater terrestrial hazard from atmospheric explosions such as those that occurred over Revelstoke or Tunguska4,5. Here I show that explosions due to Spacewatch objects with diameters less than 50 m (having kinetic energies below about 10 megatonnes high-explosive equivalent) typically occur too high in the atmosphere to cause substantial surface damage. Exclusive of relatively rare iron objects, no comet or asteroid with an energy below approximately 2 megatonnes threatens the Earth's surface. The high flux of small Earth-crossing objects identified by Spacewatch therefore does not imply a greater terrestrial hazard.
RP CHYBA, CF (corresponding author), NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,CODE 693,GREENBELT,MD 20771, USA.
NR 21
TC 28
Z9 29
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 701
EP 703
DI 10.1038/363701a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900049
DA 2026-03-10
ER

PT J
AU QIAN, YW
   WANG, YCJ
   HOLLINGSWORTH, RE
   JONES, D
   LING, N
   LEE, EYHP
AF QIAN, YW
   WANG, YCJ
   HOLLINGSWORTH, RE
   JONES, D
   LING, N
   LEE, EYHP
TI A RETINOBLASTOMA-BINDING PROTEIN RELATED TO A NEGATIVE REGULATOR OF RAS IN YEAST
SO NATURE
LA English
DT Article
ID sv40 t-antigen; gene-product; susceptibility gene; cellular proteins; messenger-rnas; identification; transcription; cloning; translation; region
AB THE growth suppression function of the retinoblastoma protein (Rb) is thought to be mediated by Rb binding to cellular proteins1. p48 is one of the major proteins that binds to a putative functional domain at the carboxy terminus of the Rb protein2. Here we report the isolation of a full-length complementary DNA (RbAp48) encoding p48. Complex formation between p48 and Rb occurs in vitro and in vivo, and apparently involves direct interaction between the proteins. Like Rb, p48 is a ubiquitously expressed nuclear protein. RbAp48 share sequence homology with MSI1, a negative regulator of the Ras-cyclic AMP pathway in the yeast Saccharomyces cerevisiae3. Furthermore, like MSI1, human RbAp48 suppresses the heat-shock sensitivity of the yeast ira1 strains and RAS2val19 strains. Interaction with p48 may be one of the mechanisms for suppression of growth mediated by Rb.
C1 UNIV TEXAS,HLTH SCI CTR,INST BIOTECHNOL,CTR MOLEC MED,15355 LAMBDA DR,SAN ANTONIO,TX 78245.
   WHITTIER INST,LA JOLLA,CA 92037.
C3 University of Texas System; University of Texas at San Antonio
NR 22
TC 259
Z9 307
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 648
EP 652
DI 10.1038/364648a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100059
PM 8350924
DA 2026-03-10
ER

PT J
AU MIKI, T
   SMITH, CL
   LONG, JE
   EVA, A
   FLEMING, TP
AF MIKI, T
   SMITH, CL
   LONG, JE
   EVA, A
   FLEMING, TP
TI ONCOGENE ECT2 IS RELATED TO REGULATORS OF SMALL GTP-BINDING PROTEINS
SO NATURE
LA English
DT Article
ID expression cdna cloning; cell-division-cycle; saccharomyces-cerevisiae; nucleotide-sequence; molecular-cloning; human homolog; abl-oncogene; gene; yeast; bcr
AB WE have developed an efficient expression cloning system that allows rapid isolation of complementary DNAs able to induce the transformed phenotype1,2. We searched for molecules expressed in epithelial cells and possessing transforming potential to fibroblasts, and cloned a cDNA for the normal receptor of a growth factor secreted by NIH/3T3 cells3,4. Here we report a second novel transforming gene, ect2. The isolated cDNA is activated by amino-terminal truncation of the normal product. The Ect2 protein has sequence similarity within a central core of 255 amino acids with the products of the breakpoint cluster gene, bcr (ref. 5), the yeast cell cycle gene, CDC24 (ref. 6), and the dbl oncogene7. Each of these genes encodes regulatory molecules or effectors for Rho-like small GTP-binding proteins8-10. The baculovirus-expressed Ect2 protein could bind highly specifically to Rho and Rac proteins, whereas the dbl product showed broader binding specificity to Rho family proteins. Thus ect2 is a new member of an expanding family, whose products have transforming properties and interact with Rho-like proteins of the Ras superfamily.
RP MIKI, T (corresponding author), NCI,CELLULAR & MOLEC BIOL LAB,BLDG 37-1E24,9000 ROCKVILLE PIKE,BETHESDA,MD 20892, USA.
NR 27
TC 269
Z9 307
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 462
EP 465
DI 10.1038/362462a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400088
PM 8464478
DA 2026-03-10
ER

PT J
AU HAWKINS, MRS
AF HAWKINS, MRS
TI GRAVITATIONAL MICROLENSING, QUASAR VARIABILITY AND MISSING MATTER
SO NATURE
LA English
DT Article
ID cosmological density; objects
AB QUASARs have long been known to vary in magnitude1, and it now appears that all quasars are to some extent variable2.  In a few extreme cases, quasar luminosities have varied over several magnitudes on a timescale of months; this behaviour is normally accompanied by other phenomena (such as radio emission or enhanced polarization) indicative of processes intrinsic to the quasars. Long-term luminosity variations, while less dramatic, are much more common, but their origin remains poorly understood. Here I investigate this longer-term behaviour for a sample of approximately 300 quasars at redshifts ranging from 1 to 3, whose optical magnitudes have been measured periodically for 17 years.  I show that there is a positive correlation between the timescale of variability and the average luminosity, but little evidence for an increase in timescale due to redshift (and hence time dilation). These findings are inconsistent with any known variability mechanism intrinsic to quasars, but can be explained by gravitational lensing of the quasar images by compact substellar objects along the lines of sight. If this interpretation is correct, the population of lensing objects must have a density of at least 0.1 of the critical cosmological density.
RP HAWKINS, MRS (corresponding author), ROYAL OBSERV,BLACKFORD HILL,EDINBURGH EH9 3HJ,MIDLOTHIAN,SCOTLAND.
NR 14
TC 137
Z9 147
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 242
EP 245
DI 10.1038/366242a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500055
DA 2026-03-10
ER

PT J
AU MADEJSKI, GM
   DONE, C
   TURNER, TJ
   MUSHOTZKY, RF
   SERLEMITSOS, P
   FIORE, F
   SIKORA, M
   BEGELMAN, MC
AF MADEJSKI, GM
   DONE, C
   TURNER, TJ
   MUSHOTZKY, RF
   SERLEMITSOS, P
   FIORE, F
   SIKORA, M
   BEGELMAN, MC
TI SOLVING THE MYSTERY OF THE X-RAY PERIODICITY IN THE SEYFERT-GALAXY NGC6814
SO NATURE
LA English
DT Article
ID variability; ngc-6814; line
AB ACTIVE galaxies, of which Seyfert galaxies are a subgroup, are thought to be powered by the accretion of gas onto a massive black hole at the galaxy centre; the X-rays emitted by active galactic nuclei arise from the heated, infalling gas. The observed rapid variability of this X-ray emission requires a compact source, providing additional support for the black-hole hypothesis. The Seyfert galaxy NGC6814 has been thought to be unique among active galaxies, in exhibiting not simply variability but a periodicity of approximately 12,100 s in its X-ray luminosity1-4. Many exotic theories have been proposed to explain this periodicity, including, gravitational lensing of hotspots on the accretion disk by the central black hole5-7 or the effects of a captured star orbiting the black hole4,8-10. Here we show, using data from the Rosat X-ray telescope, that although the 12,100 s period is indeed real and stable, it is not associated with NGC6814. Instead, the periodic emission arises from another source, 37 arcmin away from NGC6814, which is probably an object in our Galaxy-for example, a white dwarf accreting gas (from a giant companion) onto its poles.
C1 UNIV SPACE RES ASSOC,GREENBELT,MD 20771.
   CTR ASTROPHYS,CAMBRIDGE,MA 02138.
   COPERNICUS ASTRON CTR,PL-00716 WARSAW,POLAND.
   UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309.
   UNIV COLORADO,DEPT ASTROPHYS PLANETARY & ATMOSPHER SCI,BOULDER,CO 80309.
C3 Universities Space Research Association (USRA); University of Colorado System; University of Colorado Boulder; University of Colorado System; University of Colorado Boulder
RP MADEJSKI, GM (corresponding author), NASA,GODDARD SPACE FLIGHT CTR,HIGH ENERGY ASTROPHYS LAB,CODE 666,GREENBELT,MD 20771, USA.
NR 25
TC 57
Z9 59
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 626
EP 628
DI 10.1038/365626a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600051
DA 2026-03-10
ER

PT J
AU WILSON, MVH
   CALDWELL, MW
AF WILSON, MVH
   CALDWELL, MW
TI NEW SILURIAN AND DEVONIAN FORK-TAILED THELODONTS ARE JAWLESS VERTEBRATES WITH STOMACHS AND DEEP BODIES
SO NATURE
LA English
DT Article
AB ALL agnathans (jawless vertebrates) are generally considered to have lacked a stomach, as do the living lampreys. Thelodonts are agnathans of Silurian and Devonian age whose bodies were covered by tiny, hollow, tooth-like scales which are useful for correlating rocks. We have discovered a new group of agnathans with 'thelodont' scales but with a body plan very different from that of previously known thelodonts. Sediment infillings reveal gut morphology that includes a probable stomach, suggesting that stomachs arose before jaws in vertebrate evolution. These new fork-tailed 'thelodonts' are also the first agnathans known to have deep, compressed bodies. They represent an important new clade of early vertebrates and are potential close relatives of gnathostomes (jawed vertebrates).
C1 UNIV ALBERTA,VERTEBRATE PALEONTOL LAB,EDMONTON T6G 2E9,ALBERTA,CANADA.
C3 University of Alberta
RP WILSON, MVH (corresponding author), UNIV ALBERTA,DEPT ZOOL,EDMONTON T6G 2E9,ALBERTA,CANADA.
NR 30
TC 44
Z9 50
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 442
EP 444
DI 10.1038/361442a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300057
DA 2026-03-10
ER

PT J
AU SIGURDSSON, S
   HERNQUIST, L
AF SIGURDSSON, S
   HERNQUIST, L
TI PRIMORDIAL BLACK-HOLES IN GLOBULAR-CLUSTERS
SO NATURE
LA English
DT Article
ID binary; pulsars; systems; mass
AB IT HAS recently been recognized1 that significant numbers of medium-mass black holes (of order 10 solar masses) should form in globular clusters during the early stages of their evolution. Here we explore the dynamical and observational consequences of the presence of such a primordial black-hole population in a globular cluster. The holes initially segregate to the cluster cores, where they form binary and multiple black-hole systems. The subsequent dynamical evolution of the black-hole population ejects most of the holes on a relatively short timescale: a typical cluster will retain between zero and four black holes in its core, and possibly a few black holes in its halo. The presence of binary, triple and quadruple black-hole systems in cluster cores will disrupt main-sequence and giant stellar binaries; this may account for the observed2 anomalies in the distribution of binaries in globular clusters. Furthermore, tidal interactions between a multiple black-hole system and a red-giant giant star can remove much of the red giant's stellar envelope, which may explain the puzzling absence3 of larger red giants in the cores of some very dense clusters.
RP SIGURDSSON, S (corresponding author), UNIV CALIF SANTA CRUZ,BOARD STUDIES ASTRON & ASTROPHYS,SANTA CRUZ,CA 95064, USA.
NR 27
TC 339
Z9 378
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 423
EP 425
DI 10.1038/364423a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000047
DA 2026-03-10
ER

PT J
AU BERCHTOLD, H
   RESHETNIKOVA, L
   REISER, COA
   SCHIRMER, NK
   SPRINZL, M
   HILGENFELD, R
AF BERCHTOLD, H
   RESHETNIKOVA, L
   REISER, COA
   SCHIRMER, NK
   SPRINZL, M
   HILGENFELD, R
TI CRYSTAL-STRUCTURE OF ACTIVE ELONGATION-FACTOR TU REVEALS MAJOR DOMAIN REARRANGEMENTS
SO NATURE
LA English
DT Article
ID polypeptide-chain-elongation; aminoacyl-transfer rna; factor-ef-tu; thermus-thermophilus hb8; escherichia-coli; binding-site; protein-biosynthesis; extreme thermophile; nucleotide binding; gtp hydrolysis
AB The crystal structure of intact elongation factor Tu (EF-Tu) from Thermus thermophilus has been determined and refined at an effective resolution of 1.7 angstrom, with incorporation of data extending to 1.45 angstrom. The effector region, including interaction sites for the ribosome and for transfer RNA, is well defined. Molecular mechanisms are proposed for transduction and amplification of the signal induced by GTP binding as well as for the intrinsic and effector-enhanced GTPase activity of EF-Tu. Comparison of the structure with that of EF-Tu-GDP reveals major mutual rearrangements of the three domains of the molecule.
C1 HOECHST AKT GESELL,CENT RES G865A,PROT CRYSTALLOG,D-65926 FRANKFURT,GERMANY.
   UNIV BAYREUTH,BIOCHEM LAB,D-95440 BAYREUTH,GERMANY.
   VA ENGELHARDT MOLEC BIOL INST,MOSCOW 117984,RUSSIA.
C3 Sanofi-Aventis; Sanofi Germany; University of Bayreuth; Russian Academy of Sciences; Engelhardt Institute of Molecular Biology, RAS
NR 50
TC 517
Z9 556
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 126
EP 132
DI 10.1038/365126a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200038
PM 8371755
DA 2026-03-10
ER

PT J
AU BRUNET, AP
   HUANG, ES
   HUFFINE, ME
   LOEB, JE
   WELTMAN, RJ
   HECHT, MH
AF BRUNET, AP
   HUANG, ES
   HUFFINE, ME
   LOEB, JE
   WELTMAN, RJ
   HECHT, MH
TI THE ROLE OF TURNS IN THE STRUCTURE OF AN ALPHA-HELICAL PROTEIN
SO NATURE
LA English
DT Article
ID folding unfolding pathways; monte-carlo simulations; peptide-fragments; escherichia-coli; denovo design; mutagenesis; sequence; cytochrome-b562; conformation; pentapeptides
AB THE turns joining segments of secondary structure have been proposed to be key elements in dictating the folded structures of native proteins1-9. An alternative view assumes that turns play a passive role and are merely default structures that occur as a consequence of interactions between antiparallel segments of secondary structure, with chain reversal being dictated by the context surrounding the turn and not by the sequence of the turn itself10,11. The solvent-exposure of turns and their tolerance to evolutionary variance suggests that they may have little or no effect on the formation of native structures. Previous investigations have focused on various types of beta-turns that connect antiparallel beta-strands1-3,12,13, with comparatively little reported on the structural role of interhelical turns. Here we probe the structural importance of such a turn in an antiparallel 4-helix bundle by randomly substituting an interhelical tripeptide in cytochrome b-562 with many different amino-acid sequences. Thirty-one of the resulting substituted proteins were characterized and all of them were shown to fold into stable, native-like structures. These results suggest that this interhelical turn does not does not play a dominant role in determining the folded structure of this antiparallel 4-helix bundle.
C1 PRINCETON UNIV, DEPT CHEM, PRINCETON, NJ 08544 USA.
   PRINCETON UNIV, DEPT MOLEC BIOL, PRINCETON, NJ 08544 USA.
C3 Princeton University; Princeton University
NR 37
TC 105
Z9 114
U1 0
U2 7
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 355
EP 358
DI 10.1038/364355a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000063
PM 8332196
DA 2026-03-10
ER

PT J
AU MULLER, DA
   TZOU, Y
   RAJ, R
   SILCOX, J
AF MULLER, DA
   TZOU, Y
   RAJ, R
   SILCOX, J
TI MAPPING SP(2) AND SP(3) STATES OF CARBON AT SUBNANOMETER SPATIAL-RESOLUTION
SO NATURE
LA English
DT Article
ID electron-energy-loss; vapor-deposition; diamond; silicon; nucleation; microscope; image
AB THE potential for diverse applications of diamond1 has been enhanced by the discovery of the chemical vapour deposition process2,3 for film formation. The growth of hetero-epitaxial diamond films on silicon is a particularly attractive goal, but only polycrystalline films have so far been prepared in this way4. Because of the large lattice mismatch, thin intermediate layers (interlayers5) are formed between the diamond and silicon phases, which may contain crystalline SiC (refs 6, 7) or amorphous compounds (SiC, carbon8 and SiO2). An understanding of how diamond nucleates5,9-11, and the role of these interlayers, requires a detailed knowledge of the nature of carbon bonding (sp2 or sp3) at the interface. Here we report the use of transmission electron energy-loss spectroscopy (EELS) to obtain a map of sp2  and sp3 carbon at a spatial resolution of less than a nanometre across the silicon-diamond interface. We find that diamond nucleates on an amorphous carbon layer, with the transition from sp2 to sp3 carbon occurring over less than one nanometre.
C1 CORNELL UNIV,DEPT MAT SCI & ENGN,ITHACA,NY 14853.
   CORNELL UNIV,SCH APPL & ENGN PHYS,ITHACA,NY 14853.
C3 Cornell University; Cornell University
RP MULLER, DA (corresponding author), CORNELL UNIV,DEPT PHYS,ITHACA,NY 14853, USA.
NR 34
TC 220
Z9 238
U1 0
U2 87
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 23
PY 1993
VL 366
IS 6457
BP 725
EP 727
DI 10.1038/366725a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MN264
UT WOS:A1993MN26400021
DA 2026-03-10
ER

PT J
AU FRAM, MS
   LESHER, CE
AF FRAM, MS
   LESHER, CE
TI GEOCHEMICAL CONSTRAINTS ON MANTLE MELTING DURING CREATION OF THE NORTH-ATLANTIC BASIN
SO NATURE
LA English
DT Article
ID continental margins; iceland plume; flood basalts; genesis; ridge; peridotite; magmatism
AB THE compositions of magmas produced by decompression melting of upwelling mantle rocks are sensitive to the extent and mean pressure of melting; these, in turn, depend respectively on the depth at which the solidus is encountered1,2 and on the thickness of the lithosphere, which provides a barrier to upwelling mantle2,3. Here we report major- and trace-element data for lavas erupted during rifting of the Greenland-European continent approximately 60 Myr ago, which show a trend to higher extents of melting at lower pressures as rifting proceeded. We attribute these changes to progressive thinning of the continental lithosphere during the initial phase of magmatism. Our analysis also shows that mantle melting began well within the garnet stability field, supporting previous suggestions4-8 that anomalously hot mantle was present beneath the region at the time of rifting. The modest extents of melting that we infer for the earliest rift lavas can largely account for their high contents of incompatible elements, thus reducing the degree of geochemical enrichment ('plume-like' character) required in the mantle source region.
C1 COLUMBIA UNIV, LAMONT DOHERTY GEOL OBSERV, PALISADES, NY 10964 USA.
   COLUMBIA UNIV, DEPT GEOL SCI, PALISADES, NY 10964 USA.
C3 Columbia University; Columbia University
RP FRAM, MS (corresponding author), UNIV CALIF DAVIS, DEPT GEOL, DAVIS, CA 95616 USA.
NR 36
TC 96
Z9 105
U1 1
U2 16
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 712
EP 715
DI 10.1038/363712a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900053
DA 2026-03-10
ER

PT J
AU ROTHE, J
   LESSLAUER, W
   LOTSCHER, H
   LANG, Y
   KOEBEL, P
   KONTGEN, F
   ALTHAGE, A
   ZINKERNAGEL, R
   STEINMETZ, M
   BLUETHMANN, H
AF ROTHE, J
   LESSLAUER, W
   LOTSCHER, H
   LANG, Y
   KOEBEL, P
   KONTGEN, F
   ALTHAGE, A
   ZINKERNAGEL, R
   STEINMETZ, M
   BLUETHMANN, H
TI MICE LACKING THE TUMOR-NECROSIS-FACTOR RECEPTOR-1 ARE RESISTANT TO TNF-MEDIATED TOXICITY BUT HIGHLY SUSCEPTIBLE TO INFECTION BY LISTERIA-MONOCYTOGENES
SO NATURE
LA English
DT Article
ID virus-replication; gamma interferon; factor-alpha; mouse; expression; cloning; interleukin-1; endotoxin; cachectin; invivo
AB TUMOUR necrosis factor (TNF), jointly referring to TNFalpha and TNFbeta, is a central mediator of immune and inflammatory responses; its activities are mediated by two distinct receptors, TNFR1 (p55) and TNFR2 (p75) (reviewed in refs 1-3). The cytoplasmic domains of the TNFRs are unrelated, suggesting that they link to different intracellular signalling pathways4. Although most TNF responses have been assigned to one or the other of the TNF receptors (mostly TNFR1), there is no generally accepted model for the physiological role of the two receptor types. To investigate the role of TNFR1 in beneficial and detrimental activities of TNF, we generated TNFR1-deficient mice by gene targeting. We report here that mice homozygous for a disrupted Tnfr1 allele (Tnfr1(0)) are resistant to the lethal effect of low doses of lipopolysaccharide after sensitization with D-galactosamine, but remain sensitive to high doses of lipopolysaccharide. The increased susceptibility of Tnfr1(0)/Tnfr1(0) mutant mice to infection with the facultative intracellular bacterium Listeria monocytogenes indicates an essential role of TNF in nonspecific immunity.
C1 F HOFFMANN LA ROCHE & CO LTD, DEPT BIOL, PHARMACEUT RES NEW TECHNOL, CH-4002 BASEL, SWITZERLAND.
   UNIV ZURICH, INST EXPTL IMMUNOL, CH-8057 ZURICH, SWITZERLAND.
C3 Roche Holding; University of Zurich
NR 32
TC 1159
Z9 1250
U1 1
U2 28
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 798
EP 802
DI 10.1038/364798a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100055
PM 8395024
DA 2026-03-10
ER

PT J
AU SCHMID, MF
   ROBINSON, JP
   DASGUPTA, BR
AF SCHMID, MF
   ROBINSON, JP
   DASGUPTA, BR
TI DIRECT VISUALIZATION OF BOTULINUM NEUROTOXIN-INDUCED CHANNELS IN PHOSPHOLIPID-VESICLES
SO NATURE
LA English
DT Article
ID tetanus toxin; electron; membranes; images
AB THE seven botulinum neurotoxin (NT) serotypes produced by strains of Clostridium botulinum inhibit neurotransmitter release from synaptic vesicles. Neurotoxin is synthesized as a roughly 150K single-chain protein. Proteolysis produces two fragments, the 50K L-chain and 100K H-chain, that remain linked by a disulphide bond. Intoxication involves membrane attachment by the C-terminal half of the H-chain, endocytotic/lysosomal internalization, vesicle channel formation mediated by the 50K N-terminal half of the H-chain at low pH, and finally blockade of synaptic vesicle fusion after the L-chain reaches the cytosol1-4 . We report here the visualization of the neurotoxin-membrane complex by electron cryomicroscopy and image processing. Three-dimensional reconstructions show the neurotoxin bound to the exterior of ganglioside/PC lipid vesicles and show channels entirely perforating the vesicle wall. Each channel appears to arise from the interaction of four neurotoxin molecules.
C1 BAYLOR COLL MED,WM KECK CTR COMPUTAT BIOL,HOUSTON,TX 77030.
   UNIV WISCONSIN,DEPT FOOD MICROBIOL & TOXICOL,MADISON,WI 53706.
C3 Baylor College of Medicine; University of Wisconsin System; University of Wisconsin Madison
RP SCHMID, MF (corresponding author), BAYLOR COLL MED,VERNA & MARRS MCLEAN DEPT BIOCHEM,HOUSTON,TX 77030, USA.
NR 16
TC 77
Z9 83
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 827
EP 830
DI 10.1038/364827a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100063
PM 7689178
DA 2026-03-10
ER

PT J
AU PAULESU, E
   FRITH, CD
   FRACKOWIAK, RSJ
AF PAULESU, E
   FRITH, CD
   FRACKOWIAK, RSJ
TI THE NEURAL CORRELATES OF THE VERBAL COMPONENT OF WORKING MEMORY
SO NATURE
LA English
DT Article
ID short-term-memory; pet images; speech; comprehension; store
AB BY repeating words 'in our head', verbal material (such as telephone numbers) can be kept in working memory1 almost indefinitely. This 'articulatory loop' includes a subvocal rehearsal system2-6 and a phonological store3,6-10. Little is known about neural correlates of this model of verbal short-term memory. We therefore measured regional cerebral blood flow, an index of neuronal activity, in volunteers performing a task engaging both components of the articulatory loop (short-term memory for letters)5-10 and a task which engages only the subvocal rehearsal system (rhyming judgement for letters)4,11. Stimuli were presented visually and the subjects did not speak. We report here that comparisons of distribution of cerebral blood flow in these conditions localized the phonological store to the left supramarginal gyrus whereas the subvocal rehearsal system was associated with Broca's area. This is, to our knowledge, the first demonstration of the normal anatomy of the components of the 'articulatory loop'.
C1 HAMMERSMITH HOSP, MRC, CYCLOTRON UNIT, DUCANE RD, LONDON W12 0HS, ENGLAND.
   IST SCI SAN RAFFAELE, I-20132 MILAN, ITALY.
   UCL, DEPT PSYCHOL, LONDON WC1E 6TB, ENGLAND.
C3 Imperial College London; Vita-Salute San Raffaele University; IRCCS Ospedale San Raffaele; University of London; University College London
NR 24
TC 1827
Z9 2008
U1 1
U2 129
PU NATURE RESEARCH
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 342
EP 345
DI 10.1038/362342a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600060
PM 8455719
DA 2026-03-10
ER

PT J
AU ROTZSCHKE, O
   FALK, K
   STEVANOVIC, S
   GRAHOVAC, B
   SOLOSKI, MJ
   JUNG, G
   RAMMENSEE, HG
AF ROTZSCHKE, O
   FALK, K
   STEVANOVIC, S
   GRAHOVAC, B
   SOLOSKI, MJ
   JUNG, G
   RAMMENSEE, HG
TI QA-2 MOLECULES ARE PEPTIDE RECEPTORS OF HIGHER STRINGENCY THAN ORDINARY CLASS-I MOLECULES
SO NATURE
LA English
DT Article
ID histocompatibility antigen; monoclonal-antibody; mhc molecules; expression; region; mouse; cells; identification; hla-b27; hla-a2
AB CLASS I molecules of the major histocompatibility complex (MHC) transport peptides to the cell surface for surveillance by T cells1. Ligand specificity is stringent and differs from allele to allele2-4. Here we report analysis of natural ligands of 'unconventional' glycophosphatidyl-anchored mouse class I molecules, Qa-2. The function of these molecules is unclear5,6; they can serve as recognition structures for 'unrestricted' cytotoxic T cells but have not been found to present peptides to T cells, although the DNA sequence suggests a similar peptide binding groove to that of 'conventional' class I molecules7, and other unconventional class I molecules can present antigens in a few cases8-10. Pool sequencing of natural Qa-2 ligands shows that Qa-2 molecules are indeed peptide receptors, having ligand specificity similar to that of conventional class I molecules, that is, a predominant length of nine amino acids, anchor positions, and hydrophobic termination of peptides. But ligand specificity is much more stringent than with other class I molecules: of the nine positions, two are anchors and four have rather limited occupancy.
C1 MAX PLANCK INST BIOL,IMMUNGENET ABT,CORRENSSTR 42,W-7400 TUBINGEN,GERMANY.
   UNIV TUBINGEN,INST ORGAN CHEM,W-7400 TUBINGEN 1,GERMANY.
   JOHNS HOPKINS UNIV MED,DIV MOLEC & CLIN RHEUMATOL,BALTIMORE,MD 21205.
C3 Max Planck Society; Eberhard Karls University of Tubingen; Johns Hopkins University
NR 27
TC 108
Z9 112
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 642
EP 644
DI 10.1038/361642a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600065
PM 8437623
DA 2026-03-10
ER

PT J
AU SCHUTT, CE
   MYSLIK, JC
   ROZYCKI, MD
   GOONESEKERE, NCW
   LINDBERG, U
AF SCHUTT, CE
   MYSLIK, JC
   ROZYCKI, MD
   GOONESEKERE, NCW
   LINDBERG, U
TI THE STRUCTURE OF CRYSTALLINE PROFILIN BETA-ACTIN
SO NATURE
LA English
DT Article
AB The three-dimensional structure of bovine profilin-beta-actin has been solved to 2.55 angstrom resolution by X-ray crystallography. There are several significant local changes in the structure of beta-actin compared with alpha-actin as well as an overall 5-degrees rotation between its two major domains. Actin molecules in the crystal are organized into ribbons through intermolecular contacts like those found in oligomeric protein assemblies. Profilin forms two extensive contacts with the actin ribbon, one of which appears to correspond to the solution contact in vitro.
C1 UNIV STOCKHOLM,ARRHENIUS LABS NAT SCI,WGI,DEPT ZOOL CELL BIOL,S-10691 STOCKHOLM,SWEDEN.
C3 Stockholm University
RP SCHUTT, CE (corresponding author), PRINCETON UNIV,HENRY H HOYT LAB,DEPT CHEM,PRINCETON,NJ 08544, USA.
NR 51
TC 636
Z9 735
U1 1
U2 26
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 810
EP 816
DI 10.1038/365810a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100041
PM 8413665
DA 2026-03-10
ER

PT J
AU KRAUSS, N
   HINRICHS, W
   WITT, I
   FROMME, P
   PRITZKOW, W
   DAUTER, Z
   BETZEL, C
   WILSON, KS
   WITT, HT
   SAENGER, W
AF KRAUSS, N
   HINRICHS, W
   WITT, I
   FROMME, P
   PRITZKOW, W
   DAUTER, Z
   BETZEL, C
   WILSON, KS
   WITT, HT
   SAENGER, W
TI 3-DIMENSIONAL STRUCTURE OF SYSTEM-I OF PHOTOSYNTHESIS AT 6 ANGSTROM RESOLUTION
SO NATURE
LA English
DT Article
ID cyanobacterium synechococcus-sp; pigment-protein complexes; primary electron-donor; photosystem-i; rhodopseudomonas-viridis; thylakoid membrane; crystallization; identification; orientation; crystallography
AB X-ray structure analysis shows that the monomer of trimeric photosystem I (PS I) of Synechococcus sp. consists of a catalytic domain and a smaller domain that connects the monomers. The 4Fe-4S clusters F(X), F(A) and F(B), 28 alpha-helices and 45 chlorophyll a molecules were located. The two large subunits of PS I are represented by nine alpha-helices each; they are related by a local 2-fold rotation axis passing through F(X). Electron densities close to this axis are interpreted as carriers of the electron transfer chain.
C1 TECH UNIV BERLIN, MAX VOLMER INST BIOPHYS & PHYS CHEM, W-1000 BERLIN 12, GERMANY.
   DESY, EUROPEAN MOLEC BIOL LAB OUTSTN, W-2000 HAMBURG 52, GERMANY.
C3 Technical University of Berlin; Helmholtz Association; Deutsches Elektronen-Synchrotron (DESY); European Molecular Biology Laboratory (EMBL)
RP KRAUSS, N (corresponding author), FREE UNIV BERLIN, INST KRISTALLOG, TAKUSTR 6, W-1000 BERLIN 33, GERMANY.
NR 52
TC 338
Z9 358
U1 0
U2 15
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 326
EP 331
DI 10.1038/361326a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000047
DA 2026-03-10
ER

PT J
AU KULKARNI, SR
   PREDEHL, P
   HASINGER, G
   ASCHENBACH, B
AF KULKARNI, SR
   PREDEHL, P
   HASINGER, G
   ASCHENBACH, B
TI AN ASSOCIATION BETWEEN A LONG-PERIOD PULSAR AND AN OLD SUPERNOVA REMNANT
SO NATURE
LA English
DT Article
ID emission
AB THE birth of neutron stars is expected to be accompanied by supernovae of types Ib and II (which constitute the majority). But only a few associations between neutron stars and supernova remnants are known1; most involve young pulsars with short periods. Older supernova remnants should also be accompanied by pulsars, but these would be less luminous and, because they would have spun down to longer periods, they would beam to a much smaller fraction of the sky2. This may explain why no associations of this sort have been detected previously3. Here we report a possible such association: between pulsar 2334 + 61, with a relatively long period of 0.5 s, and G114.3 + 0.3, a fairly old supernova remnant. The flat spectral index of -0.36 +/- 0.03 (refs 4, 5) and large fractional polarization suggest that the radio emission is powered by the pulsar. If so, the pulsar must have been born with a relatively short period of less than 100 ms. As the remnant is not particularly unusual morphologically, there might be many more such remnants containing pulsars that are not beamed towards us.
C1 MAX PLANCK INST EXTRATERR PHYS,W-8046 GARCHING,GERMANY.
C3 Max Planck Society
RP KULKARNI, SR (corresponding author), CALTECH,OWENS VALLEY RADIO OBSERV 10524,PASADENA,CA 91125, USA.
NR 21
TC 28
Z9 29
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 135
EP 137
DI 10.1038/362135a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800051
DA 2026-03-10
ER

PT J
AU SCHNEIDER, W
   NOLL, DC
   COHEN, JD
AF SCHNEIDER, W
   NOLL, DC
   COHEN, JD
TI FUNCTIONAL TOPOGRAPHIC MAPPING OF THE CORTICAL RIBBON IN HUMAN VISION WITH CONVENTIONAL MRI SCANNERS
SO NATURE
LA English
DT Article
ID striate cortex; brain; organization; dependence; areas; blood; time
AB THE human brain has anatomically distinct areas in which processing is laid out in space at the millimetre level with substantial variation across individuals. Activity occurs along a cortical ribbon 1.5-3 mm thick1 in response to specific stimuli2,3. Here we report the first use of cortical ribbon analysis on humans using non-invasive functional magnetic resonance imaging techniques performed with a conventional 1.5 T MRI scanner. Changes in activation were detected using T2*-weighted, gradient echo imaging sequences. Subjects observed partial field, flashing checkerboard patterns (left-right, top-bottom, half rings, and wedges). Stimuli produced magnetic resonance signal changes in the 1-8% range, varying at the millimetre scale, which showed contralateral vertically reflected patterns of activation in the visual cortex. To compare the spatial topographies across subjects, computer algorithms were used to control for the subject-unique folding of cortex, providing a flattened cortical ribbon identifying four topographically distinct areas.
C1 PITTSBURGH NMR INST, PITTSBURGH, PA 15213 USA.
   CARNEGIE MELLON UNIV, DEPT PSYCHOL, PITTSBURGH, PA 15213 USA.
C3 Carnegie Mellon University
RP SCHNEIDER, W (corresponding author), UNIV PITTSBURGH, 3939 O HARA ST, PITTSBURGH, PA 15260 USA.
NR 19
TC 172
Z9 183
U1 0
U2 8
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 150
EP 152
DI 10.1038/365150a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200045
PM 8371756
DA 2026-03-10
ER

PT J
AU PEUNOVA, N
   ENIKOLOPOV, G
AF PEUNOVA, N
   ENIKOLOPOV, G
TI AMPLIFICATION OF CALCIUM-INDUCED GENE-TRANSCRIPTION BY NITRIC-OXIDE IN NEURONAL CELLS
SO NATURE
LA English
DT Article
ID long-term potentiation; cyclic-amp; c-fos; nervous-system; factor creb; binding-protein; phosphorylation; messenger; sequence; kinases
AB NITRIC oxide (NO) is a short-lived, highly reactive gas, which has been identified as a mediator in vasodilation, an active agent in macrophage cytotoxicity and neurotoxicity, and a neurotransmitter in the central and peripheral nervous systems1-5. Production of NO by neurons is critical for facilitated synaptic transmission in models of synaptic plasticity such as long-term potentiation and long-term depression, suggesting a role for NO as a retrograde messenger that could complete a hypothetical feed-back loop by strengthening the connection between postsynaptic and presynaptic cells6-10. We report here that although alone NO has no evident effect on transcription, it can act as an amplifier of calcium signals in neuronal cells. NO and Ca2+ action have to coincide in time for amplification to occur. Experiments with a series of simplified reporter genes in combination with specific recombinant protein kinase inhibitors suggest that induction of gene activity following NO-amplified calcium action involves protein kinase A-dependent activation of the transcription factor CREB.
C1 COLD SPRING HARBOR LAB, POB 100, COLD SPRING HARBOR, NY 11724 USA.
C3 Cold Spring Harbor Laboratory
NR 29
TC 286
Z9 309
U1 0
U2 7
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 450
EP 453
DI 10.1038/364450a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000057
PM 8392663
DA 2026-03-10
ER

PT J
AU HESS, DT
   PATTERSON, SI
   SMITH, DS
   SKENE, JHP
AF HESS, DT
   PATTERSON, SI
   SMITH, DS
   SKENE, JHP
TI NEURONAL GROWTH CONE COLLAPSE AND INHIBITION OF PROTEIN FATTY ACYLATION BY NITRIC-OXIDE
SO NATURE
LA English
DT Article
ID long-term potentiation; synaptosomal-associated protein; soluble guanylate-cyclase; intercellular messenger; nervous-system; nmda receptors; complex; stimulation; cerebellum; glutamate
AB NITRIC oxide, a free-radical gas produced endogenously by several mammalian cell types1-6, has been implicated as a diffusible intercellular messenger subserving use-dependent modification of synaptic efficacy in the mature central nervous system7-10. It has been suggested on theoretical grounds that nitric oxide might play an analogous role during the establishment of ordered connections by developing neurons11. We report here that nitric oxide rapidly and reversibly inhibits growth of neurites of rat dorsal root ganglion neurons in vitro. In addition, we show that exposure to nitric oxide inhibits thioester-linked long-chain fatty acylation of neuronal proteins, possibly through a direct modification of substrate cysteine thiols. Our results demonstrate a potential role for nitric oxide in the regulation of process outgrowth and remodelling during neuronal development, which may be effected at least in part through modulation of dynamic protein fatty acylation in neuronal growth cones.
C1 DUKE UNIV,MED CTR,DEPT NEUROBIOL,DURHAM,NC 27710.
C3 Duke University
RP HESS, DT (corresponding author), VANDERBILT UNIV,MED CTR,SCH MED,DEPT CELL BIOL,NASHVILLE,TN 37232, USA.
NR 31
TC 296
Z9 307
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 562
EP 565
DI 10.1038/366562a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800069
PM 8255294
DA 2026-03-10
ER

PT J
AU CLEMENS, JD
AF CLEMENS, JD
TI EXPERIMENTAL-EVIDENCE AGAINST CO2-PROMOTED DEEP CRUSTAL MELTING
SO NATURE
LA English
DT Article
ID aluminosilicate melts; carbon-dioxide; southern india; system; solubility; pressure; co2; rocks
AB THERE has been considerable controversy regarding the role of carbon dioxide in the metamorphism and melting of the Earth's crust, fuelled principally by reports of experimental evidence for CO2-enhanced partial melting of the assemblage phlogopite mica + quartz in the model system KAlO2-MgO-SiO2-H2O-CO2(1,2). The analogous process in the crust would lead to the formation of granulite-facies rocks at temperatures characteristic of amphibolite-facies metamorphism; the granulite facies3-5 would thus be indicative not of unusually high temperatures, but of the influx of carbonic fluids''. Moreover, the similarity of their low-temperature melts to the compositions of some calc-alkaline lamprophyres led Peterson and Newton2 to suggest that such magmas might be generated by the introduction of CO2-rich fluids, providing a means of large-scale mass transfer in the deep crust. These ideas have been highly influential6, but there are aspects of Peterson and Newton's results that are hard to reconcile with other available data. I have accordingly tried to replicate the results of refs 1 and 2 but, as I report here, have been unable to do so. The present results thus cast doubt on the general idea of melt fluxing by CO2, and the formation of magnesium- and CO2-rich magmas at crustal pressures.
RP CLEMENS, JD (corresponding author), UNIV MANCHESTER,DEPT GEOL,MANCHESTER M13 9PL,LANCS,ENGLAND.
NR 24
TC 31
Z9 32
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 336
EP 338
DI 10.1038/363336a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700048
DA 2026-03-10
ER

PT J
AU ZHANG, XF
   SETTLEMAN, J
   KYRIAKIS, JM
   TAKEUCHISUZUKI, E
   ELLEDGE, SJ
   MARSHALL, MS
   BRUDER, JT
   RAPP, UR
   AVRUCH, J
AF ZHANG, XF
   SETTLEMAN, J
   KYRIAKIS, JM
   TAKEUCHISUZUKI, E
   ELLEDGE, SJ
   MARSHALL, MS
   BRUDER, JT
   RAPP, UR
   AVRUCH, J
TI NORMAL AND ONCOGENIC P21(RAS) PROTEINS BIND TO THE AMINO-TERMINAL REGULATORY DOMAIN OF C-RAF-1
SO NATURE
LA English
DT Article
ID s6 kinase-ii; xenopus oocytes; signal transduction; suppressor activity; ras-p21 gtpase; ras; activation; serine; raf-1; growth
AB In higher eukaryotes, the Ras and Raf-1 proto-oncoproteins transduce growth and differentiation signals initiated by tyrosine kinases. The Ras polypeptide and the amino-terminal regulatory domain of Raf-1(residues 1-257) are shown to interact, directly in vitro and in a yeast expression system. Raf-1(1-257) binds GTP-Ras in preference to GDP-Ras, and inhibits Ras-GAP activity. Mutations in and around the Ras effector domain impair Ras binding to Raf-1(1-257) and Ras transforming activity in parallel.
C1 HARVARD UNIV, SCH MED, DIABET UNIT, 149 13TH ST, BOSTON, MA 02129 USA.
   HARVARD UNIV, SCH MED, MED SERV, BOSTON, MA 02129 USA.
   HARVARD UNIV, SCH MED, DEPT MED, BOSTON, MA 02129 USA.
   MASSACHUSETTS GEN HOSP E, CTR CANC, BOSTON, MA 02129 USA.
   BAYLOR COLL MED, DEPT BIOCHEM, HOUSTON, TX 77030 USA.
   NCI, FREDERICK CANC RES & DEV CTR, VIRAL CARCINOGENESIS LAB, FREDERICK, MD 21702 USA.
   INDIANA UNIV, SCH MED, DEPT MED, HEMATOL ONCOL SECT, INDIANAPOLIS, IN 46202 USA.
   INDIANA UNIV, SCH MED, WALTHER ONCOL CTR, INDIANAPOLIS, IN 46202 USA.
C3 Harvard University; Harvard Medical School; Harvard University; Harvard Medical School; Harvard University; Harvard Medical School; Baylor College of Medicine; National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI); Science Applications International Corporation (SAIC); SAIC-Frederick; Indiana University System; Indiana University Indianapolis; Indiana University System; Indiana University Indianapolis; Walther Cancer Foundation
NR 48
TC 827
Z9 933
U1 0
U2 15
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 308
EP 313
DI 10.1038/364308a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000047
PM 8332187
DA 2026-03-10
ER

PT J
AU ELLINOR, PT
   ZHANG, JF
   RANDALL, AD
   ZHOU, M
   SCHWARZ, TL
   TSIEN, RW
   HORNE, WA
AF ELLINOR, PT
   ZHANG, JF
   RANDALL, AD
   ZHOU, M
   SCHWARZ, TL
   TSIEN, RW
   HORNE, WA
TI FUNCTIONAL EXPRESSION OF A RAPIDLY INACTIVATING NEURONAL CALCIUM-CHANNEL
SO NATURE
LA English
DT Article
ID chick sensory neurons; electric organ; omega-conotoxin; nerve-terminals; cells; receptor; currents; binding
AB DIVERSE types of calcium channels in vertebrate neurons are important in linking electrical activity to transmitter release, gene expression and modulation of membrane excitability1. Four classes of Ca2+ channels (T, N, L and P-type) have been distinguished2-6 on the basis of their electrophysiological and pharmacological properties. Most of the recently cloned Ca2+ channels7-16 fit within this functional classification. But one major branch of the Ca2+ channel gene family, including BII (ref. 15) and doe-1 (ref. 16), has not been functionally characterized. We report here the expression of doe-1 and show that it is a high-voltage-activated (HVA) Ca2+ channel that inactivates more rapidly than previously expressed calcium channels. Unlike L-type or P-type channels, doe-1 is not blocked by dihydropyridine antagonists or the peptide toxin omega-Aga-IVA, respectively. In contrast to a previously cloned N-type channel14, doe-I block by omega-CTx-GVIA requires micromolar toxin and is readily reversible. Unlike most HVA channels, doe-1 also shows unusual sensitivity to block by Ni2+. Thus, doe-1 is an HVA Ca2+ channel with novel functional properties. We have identified a Ca2+ channel current in rat cerebellar granule neurons that resembles doe-1 in many kinetic and pharmacological features.
C1 STANFORD UNIV,MED CTR,DEPT MOLEC & CELLULAR PHYSIOL,STANFORD,CA 94305.
   CORNELL UNIV,COLL VET MED,DEPT PHARMACOL,ITHACA,NY 14853.
C3 Stanford University; Cornell University
NR 33
TC 250
Z9 272
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 455
EP 458
DI 10.1038/363455a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800060
PM 8389006
DA 2026-03-10
ER

PT J
AU FRANK, S
   LAUTERBUR, PC
AF FRANK, S
   LAUTERBUR, PC
TI VOLTAGE-SENSITIVE MAGNETIC GELS AS MAGNETIC-RESONANCE MONITORING AGENTS
SO NATURE
LA English
DT Article
ID phase-transition; electric-field; systems
AB MANY polymer gels undergo a volume phase transition in electric fields1-5. We  report here the synthesis of a Polyelectrolyte gel that incorporates magnetic particles of iron oxide into the polymer network; these particles couple the gel volume transition to the NMR relaxation times of the surrounding water. We find that the water proton relaxation rates (T2(-1)) in aqueous suspensions of particles of the magnetic gel increase significantly in an electric field. Such changes can also be induced by the hyperpolarization of red blood cells in the suspension, presumably as a result of the electric fields at the cell membrane surfaces. These gels may play a part in magnetic resonance imaging analogous to that of voltage-sensitive dyes in optical imaging6-9.
C1 UNIV ILLINOIS,BIOMED MAGNET RESONANCE LAB,1307 W PK ST,URBANA,IL 61801.
C3 University of Illinois System; University of Illinois Urbana-Champaign
NR 23
TC 71
Z9 75
U1 0
U2 19
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 334
EP 336
DI 10.1038/363334a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700047
PM 8497316
DA 2026-03-10
ER

PT J
AU MAEKAWA, H
   SHOZUL, M
   ISHII, T
   FRYER, P
   PEARCE, JA
AF MAEKAWA, H
   SHOZUL, M
   ISHII, T
   FRYER, P
   PEARCE, JA
TI BLUESCHIST METAMORPHISM IN AN ACTIVE SUBDUCTION ZONE
SO NATURE
LA English
DT Article
ID california; origin; emplacement; japan
AB THE high-pressure, low-temperature metamorphic rocks known as blueschists have long been considered to form in subduction zones, where the descent of a relatively cold slab leads to the occurrence of unusually low temperatures at mantle pressures. Until now, however, the link between blueschist-facies rocks and subduction zones has been indirect, relying on a spatial association of blueschists with old subduction complexes, and estimates of the geothermal gradients likely to exist in subduction zones. Here we strengthen this link, by reporting the discovery of blueschist-facies minerals (lawsonite, aragonite, sodic pyroxene and blue amphibole) in clasts from a serpentinite seamount in the forearc of the active Mariana subduction zone. The metamorphic conditions estimated from the mineral compositions are 150-250-degrees-C and 5-6 kbar (16-20 km depth). The rocks must have been entrained in rising serpentine mud diapirs, and extruded from mud volcanoes onto the sea floor. Further study of these rocks may provide new insight into the tectonics of trench-forearc systems, and in particular, the processes by which blueschist-facies clasts come to be associated with forearc sediments in ancient subduction complexes.
C1 UNIV HAWAII MANOA,DEPT GEOL & GEOPHYS,HONOLULU,HI 96822.
   UNIV TOKYO,OCEAN RES INST,NAKANO,TOKYO 164,JAPAN.
   UNIV DURHAM,DEPT GEOL SCI,DURHAM DH1 3LE,ENGLAND.
C3 University of Hawaii System; University of Hawaii Manoa; University of Tokyo; Durham University
RP MAEKAWA, H (corresponding author), KOBE UNIV,FAC SCI,DEPT EARTH & PLANETARY SCI,KOBE 657,JAPAN.
NR 30
TC 132
Z9 144
U1 2
U2 32
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 520
EP 523
DI 10.1038/364520a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700051
DA 2026-03-10
ER

PT J
AU ENQUIST, M
   ARAK, A
AF ENQUIST, M
   ARAK, A
TI SELECTION OF EXAGGERATED MALE TRAITS BY FEMALE AESTHETIC SENSES
SO NATURE
LA English
DT Article
ID sexual selection; preferences; evolution
AB DARWIN1 suggested that many apparently deleterious secondary sexual characters in males, such as bright colours, elaborate ornaments and conspicuous displays, evolved as a result of female choice. Darwin never tried to explain the crucial agent of selection, that females have preferences for exaggerated male traits. Rather, he took it for granted that females of many species possess a 'sense of the beautiful', akin to the aesthetic sense in humans. The question of why such preferences evolve remains a controversial issue2,3 . Here we report that mechanisms concerned with signal recognition possess inevitable biases in response that act as important agents of selection on signal form. The existence of such biases may be sufficient to explain the evolution of exaggerated male secondary sexual traits, and elaborate signals in general.
RP ENQUIST, M (corresponding author), UNIV STOCKHOLM,DEPT ZOOL,S-10691 STOCKHOLM,SWEDEN.
NR 13
TC 155
Z9 167
U1 0
U2 51
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 446
EP 448
DI 10.1038/361446a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300059
PM 8429883
DA 2026-03-10
ER

PT J
AU HARDIE, RC
   PERETZ, A
   SUSSTOBY, E
   ROMGLAS, A
   BISHOP, SA
   SELINGER, Z
   MINKE, B
AF HARDIE, RC
   PERETZ, A
   SUSSTOBY, E
   ROMGLAS, A
   BISHOP, SA
   SELINGER, Z
   MINKE, B
TI PROTEIN-KINASE-C IS REQUIRED FOR LIGHT ADAPTATION IN DROSOPHILA PHOTORECEPTORS
SO NATURE
LA English
DT Article
ID limulus photoreceptors; invertebrate photoreceptors; inositol trisphosphate; ventral photoreceptors; fly photoreceptors; mutant; phototransduction; excitation; polyphosphate; deactivation
AB PROTEIN kinase C (PKC) is a key enzyme for many cellular processes1,2 but its physiological roles are poorly understood. An excellent opportunity to investigate the function of PKC has been provided by the identification of an eye-specific PKC in Drosophila3-5 and a null PKC mutant, inaC(P209) (refs 5,6). Bright conditioning lights delivered to inaC photoreceptors lead to an abnormal loss of sensitivity in whole cell recordings from dissociated ommatidia; this has been interpreted as 'hyperadaptation' and PKC's role has been suggested to be distinct from light adaptation5. A presumably related finding is that during intense light, the response of inaC declines to baseline6. Invertebrate photoreceptors use the phosphoinositide signalling cascade7-12, responding to single photons with so-called quantum bumps13 which sum to form the macroscopic response to light14-16. Light adaptation allows photoreceptors to adjust their sensitivity over the enormous range of ambient intensities14,17. Although the molecular mechanism of light adaptation remains obscure, it is a negative-feedback process12 mediated by a rise in cytosolic calcium12,18 and a decrease in bump size12,14-16. We now show that under physiological conditions light adaptation is severely reduced in inaC, suggesting that eye-specific PKC, itself activated by a rise in cytosolic calcium4,5 and diacylglycerol, is required for adaptation. Furthermore, we show that in the absence of PKC individual bumps fail to terminate normally, an effect that can account for the pleiotropic manifestations of the inaC phenotype.
C1 HEBREW UNIV JERUSALEM,MINERVA CTR STUDIES VISUAL TRANSDUCT,DEPT PHYSIOL,IL-91010 JERUSALEM,ISRAEL.
   UNIV CAMBRIDGE,DEPT ZOOL,CAMBRIDGE CB2 3EJ,ENGLAND.
   HEBREW UNIV JERUSALEM,MINERVA CTR STUDIES VISUAL TRANSDUCT,DEPT BIOL CHEM,IL-91010 JERUSALEM,ISRAEL.
C3 Hebrew University of Jerusalem; University of Cambridge; Hebrew University of Jerusalem
NR 34
TC 135
Z9 149
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 634
EP 637
DI 10.1038/363634a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900058
PM 8510756
DA 2026-03-10
ER

PT J
AU NOEL, JP
   HAMM, HE
   SIGLER, PB
AF NOEL, JP
   HAMM, HE
   SIGLER, PB
TI THE 2.2-ANGSTROM CRYSTAL-STRUCTURE OF TRANSDUCIN-ALPHA COMPLEXED WITH GTP-GAMMA-S
SO NATURE
LA English
DT Article
ID amino-acid-sequence; rod outer segments; g-protein; biochemical-property; adenylate-cyclase; binding proteins; cdna sequence; ras p21; subunit; identification
AB The 2.2 angstrom crystal structure of activated rod transducin, G(talpha) . GTPgammaS, shows the bound GTPgammaS molecule occluded deep in a cleft between a domain structurally homologous to small GTPases and a helical domain unique to heterotrimeric G proteins. The structure, when combined with biochemical and genetic studies, suggests: how an activated receptor might open this cleft to allow nucleotide exchange; a mechanism for GTP-induced changes in effector and receptor binding surfaces; and a mechanism for GTPase activity not evident from previous data.
C1 YALE UNIV, BOYER CTR MOLEC MED, DEPT MOLEC BIOPHYS & BIOCHEM, 295 CONGRESS AVE, NEW HAVEN, CT 06510 USA.
   YALE UNIV, BOYER CTR MOLEC MED, HOWARD HUGHES MED INST, NEW HAVEN, CT 06510 USA.
   UNIV ILLINOIS, DEPT PHYSIOL & BIOPHYS, CHICAGO, IL 60680 USA.
   UNIV SASSARI, IST FISIOL GEN & CHIM BIOL, I-07100 SASSARI, ITALY.
C3 Yale University; Howard Hughes Medical Institute; Yale University; University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital; University of Sassari
NR 52
TC 741
Z9 837
U1 0
U2 21
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 654
EP 663
DI 10.1038/366654a0
PG 10
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500060
PM 8259210
DA 2026-03-10
ER

PT J
AU ORR, HA
AF ORR, HA
TI HALDANE RULE HAS MULTIPLE GENETIC CAUSES
SO NATURE
LA English
DT Article
AB HALDANE'S rule states that ''When in the F1 offspring of two different animal races one sex is absent, rare, or sterile, that sex is the heterozygous [heterogametic or XY] sex''1. This rule represents one of the few patterns characterizing animal speciation2,3. Traditional explanations of Haldane's rule1,4-6 claim that heterogametic hybrids are unfit because they lack an X chromosome that is 'compatible' with the autosomes of one species. Recent work2,7 shows that this explanation is incorrect for hybrid sterility: contrary to prediction, homogametic hybrids carrying both X chromosomes from the same species remain fertile. Until now, similar tests have not been performed for hybrid inviability. Here I show that homogametic hybrids who carry both X chromosomes from the same species are inviable. These results show that the genetic causes of Haldane's rule differ for hybrid sterility versus inviability. Haldane's rule does not, therefore, have a single genetic basis.
RP ORR, HA (corresponding author), UNIV CALIF DAVIS,CTR POPULAT BIOL,DAVIS,CA 95616, USA.
NR 15
TC 94
Z9 105
U1 0
U2 20
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 532
EP 533
DI 10.1038/361532a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400058
PM 8429905
DA 2026-03-10
ER

PT J
AU ROBERTS, WM
AF ROBERTS, WM
TI SPATIAL CALCIUM BUFFERING IN SACCULAR HAIR-CELLS
SO NATURE
LA English
DT Article
ID binding protein; transmitter release; rana-catesbeiana; active zones; bull-frog; diffusion; localization; selectivity; transport; ions
AB THE potential importance of intracellular calcium-binding proteins in rapid and highly localized Ca2+ signalling is poorly understood. During fast synaptic transmission, which occurs at specialized active zones where Ca2+ diffuses only a few tens of nanometres from channels to neurotransmitter release sites1, a cytoplasmic Ca2+ buffer would have to be extremely fast or present in millimolar concentrations to intercept a significant fraction of the calcium ions en route to their targets2-5. Therefore, Ca2+ buffers have been presumed to be unimportant in fast exocytosis1,6,7 and another fast calcium-mediated process, electrical resonance in hair cells4,8. Here I present evidence to the contrary by showing that hair cells in the frog sacculus contain millimolar concentrations of a mobile cytoplasmic calcium buffer that captures Ca2+ within a few microseconds after it enters through presynaptic Ca2+ channels and carries it away from the point of entry. This spatial buffering reduces the presynaptic free Ca2+ by up to 60 per cent and probably restricts the region in which the internal calcium ion concentration exceeds 1 muM to within <250 nm of each synaptic site. The buffer can thus influence both electrical resonance and synaptic transmission. Calbindin-D28K or a related protein may serve as the mobile calcium buffer, an action similar to its function in transporting Ca2+ across intestinal epithelial cells.
RP ROBERTS, WM (corresponding author), UNIV OREGON, INST NEUROSCI, EUGENE, OR 97403 USA.
NR 28
TC 238
Z9 249
U1 0
U2 4
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 74
EP 76
DI 10.1038/363074a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200062
PM 8479539
DA 2026-03-10
ER

PT J
AU SLATER, SJ
   COX, KJA
   LOMBARDI, JV
   HO, C
   KELLY, MB
   RUBIN, E
   STUBBS, CD
AF SLATER, SJ
   COX, KJA
   LOMBARDI, JV
   HO, C
   KELLY, MB
   RUBIN, E
   STUBBS, CD
TI INHIBITION OF PROTEIN-KINASE-C BY ALCOHOLS AND ANESTHETICS
SO NATURE
LA English
DT Article
ID general-anesthetics; local-anesthetics; molecular mechanisms; activation; site; membranes; alkanols; torpedo; binding
AB DESPITE almost a century of research, the mechanism of anaesthesia remains obscure and there is still no agreement on the location of the site(s) of action1-7. Because the potencies of general anaesthetics increase in proportion to their solubility in olive oil, this led to a consensus that the site is within the cell membrane 8-10. This led to theories that lipid bilayer perturbation was the primary event, which was then transmitted to a membrane protein11. But at the concentrations used clinically, such perturbations are small3. A plausible site would be in or on ion channels at the synapse, where a number of modulatory effects have been described6. A possible location for such a site would be at the protein-lipid interface5,12,13. We report here that anaesthetics inhibit protein kinase C, a key component in signal transduction. The potency is a linear function of the octanol-water partition coefficient (the Meyer-Overton rule of anaesthesia). The effect was obtained in a lipid-free assay, implicating a hydrophobic site in the protein, supporting the contention that a (membrane) protein may be a target for anaesthetic interactions14-17. In a lipid-dependent assay, a potential role of lipids in the protein-site model was demonstrated. The inhibition was absent in the isolated catalytic domain, suggesting that the site of inhibition is on the regulatory subunit, which is unique to protein kinase C.
C1 THOMAS JEFFERSON UNIV,DEPT PATHOL & CELL BIOL,PHILADELPHIA,PA 19107.
C3 Thomas Jefferson University
NR 29
TC 220
Z9 227
U1 1
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 82
EP 84
DI 10.1038/364082a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800064
PM 8316305
DA 2026-03-10
ER

PT J
AU FEANY, MB
   BUCKLEY, KM
AF FEANY, MB
   BUCKLEY, KM
TI THE SYNAPTIC VESICLE PROTEIN SYNAPTOTAGMIN PROMOTES FORMATION OF FILOPODIA IN FIBROBLASTS
SO NATURE
LA English
DT Article
ID alpha-latrotoxin receptor; synapsin-i; synaptophysin; expression; neurons; binding; cells; identification; pc12-cells; biogenesis
AB NEURONAL filopodia are actin-rich cytoplasmic extensions that are involved in motility and recognition in growth cones and maturing axonal endings. A detailed understanding of neuronal growth will depend on clarification of the membrane fusion events occurring during filopodial extension. The synaptic vesicle protein synaptotagmin seems to be intimately involved in exocytotic membrane fusion1-3. Here we show that fibroblast cell lines transfected with synaptotagmin form long, highly branched, actin-rich filopodial processes, with the expressed synaptotagmin being incorporated into the plasma membrane. In contrast, cell lines expressing either of two other synaptic vesicle proteins, SV2 or synaptophysin, generate only rudimentary processes, and, like neurons, sort SV2 and synaptophysin to small intracellular vesicles. As presynaptic calcium entry regulates synaptic vesicle fusion, our results indicate that synaptotagmin might link neuronal activity with synaptic growth.
RP FEANY, MB (corresponding author), HARVARD UNIV,SCH MED,DEPT NEUROBIOL,220 LONGWOOD AVE,BOSTON,MA 02115, USA.
NR 33
TC 62
Z9 66
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 537
EP 540
DI 10.1038/364537a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700058
PM 8166886
DA 2026-03-10
ER

PT J
AU TITTIGER, C
   WHYARD, S
   WALKER, VK
AF TITTIGER, C
   WHYARD, S
   WALKER, VK
TI A NOVEL INTRON SITE IN THE TRIOSEPHOSPHATE ISOMERASE GENE FROM THE MOSQUITO CULEX-TARSALIS
SO NATURE
LA English
DT Article
ID acid sequence data; drosophila-melanogaster; structural units; pieces; tpi
AB THE origin and function of introns in eukaryotic genes has provoked considerable debate since their discovery in 1977. Central to this issue are studies on the highly conserved enzyme, triosephosphate isomerase (TPI, EC 5.3.1.1). The 'introns early' argument suggests that introns are as old as the genes themselves and that the apparent correlation of many of the intron sites in plant, animal and fungal TPI genes with the boundaries of modules1 is evidence of the assembly of ancient proteins by exon shuffling2-4. In contrast, the 'introns late' view holds that ancient genomes contained few if any introns; introns were inserted into pre-existing genes during the last billion years5,6. We have found that the TPI gene from the mosquito, Culex tarsalis, contains an intron in a unique position that was predicted by W. Gilbert2 and the exon shuffling hypothesis.
RP TITTIGER, C (corresponding author), QUEENS UNIV,DEPT BIOL,KINGSTON K7L 3N6,ONTARIO,CANADA.
NR 24
TC 51
Z9 54
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 470
EP 472
DI 10.1038/361470a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300067
PM 8429888
DA 2026-03-10
ER

PT J
AU SILVENNOINEN, O
   IHLE, JN
   SCHLESSINGER, J
   LEVY, DE
AF SILVENNOINEN, O
   IHLE, JN
   SCHLESSINGER, J
   LEVY, DE
TI INTERFERON-INDUCED NUCLEAR SIGNALING BY JAK PROTEIN-TYROSINE KINASES
SO NATURE
LA English
DT Article
AB INTERFERONS IFN-alpha/beta and IFN-gamma act through independent cell-surface receptors, inducing gene expression through tyrosine phosphorylation of cytoplasmic transcription factors1-5. IFN-alpha stimulates phosphorylation and nuclear localization of the 84/91K and 113K subunits of latent ISGF3 (interferon-stimulated gene factor 3), which combine with the 48K DNA-binding subunit6,7 to bind regulatory elements of IFN-alpha-responsive genes8-10. IFN-gamma activates p91 alone2, inducing IFN-gamma-responsive genes through a distinct DNA element11,12. Genetic complementation studies implicated the tyrosine kinase Tyk2 in IFN-alpha signalling13 and, more recently, the related Jak2 kinase in IFN-gamma signalling14. We now present biochemical evidence for Jak-family kinase involvement in IFN signal transduction. Jak1 was activated in response to IFN-alpha and IFN-gamma; Jak2 responded exclusively to IFN-gamma. Overexpression of either Jak1 or Jak2 stimulated p91 DNA-binding activity and p91-dependent transcription. Overexpression also activated endogenous Jak kinases, suggesting that interactions between Jak kinases are required during interferon signalling.
C1 NYU, SCH MED, KAPLAN COMPREHENS, CANC CTR, NEW YORK, NY 10016 USA.
   NYU, SCH MED, DEPT PHARMACOL, NEW YORK, NY 10016 USA.
   NYU, SCH MED, DEPT PATHOL, NEW YORK, NY 10016 USA.
   ST JUDE CHILDRENS RES HOSP, DEPT BIOCHEM, MEMPHIS, TN 38105 USA.
C3 New York University; New York University; New York University; St Jude Children's Research Hospital
NR 28
TC 341
Z9 390
U1 0
U2 11
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 583
EP 585
DI 10.1038/366583a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800075
PM 7504785
DA 2026-03-10
ER

PT J
AU PLANK, T
   LANGMUIR, CH
AF PLANK, T
   LANGMUIR, CH
TI TRACING TRACE-ELEMENTS FROM SEDIMENT INPUT TO VOLCANIC OUTPUT AT SUBDUCTION ZONES
SO NATURE
LA English
DT Article
ID convergent margins; isotopic evidence; sr-isotopes; arc; plate; rocks; constraints; chemistry; magmatism; genesis
AB AT ocean trenches, sea-floor sediments may either be scraped off the subducting plate, or accompany it into the mantle. Some of the subducted sediment may then be recycled to the arc crust by magmatism1; the rest may be recycled into the mantle, and contribute to mantle heterogeneity2. Strong evidence for sediment contributions to are volcanism has come from isotope tracers, such as Pb-297 and Be-10 (refs 3-5), but a global mass balance requires consideration of element fluxes6. Here we report the sedimentary fluxes into eight trenches around the globe of trace elements that are enriched in are volcanics (Ba, Sr, K, Rb, Cs, La, Th and U)7. We show that the volcanic outputs clearly reflect the sediment inputs, once the effects of melting are taken into account8. Where the sediment flux into a trench is high for a particular element, the associated volcanics are enriched in this same element. Thus, some of the geochemical characteristics of arc volcanics can be traced back to the sediments at the trench. A mass balance of the inputs and outputs will ultimately provide estimates for how much sediment is recycled to the arc, and how much to the deeper mantle.
C1 COLUMBIA UNIV, LAMONT DOHERTY GEOL OBSERV, PALISADES, NY 10964 USA.
   COLUMBIA UNIV, DEPT GEOL SCI, PALISADES, NY 10964 USA.
C3 Columbia University; Columbia University
NR 38
TC 663
Z9 756
U1 2
U2 125
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 739
EP 743
DI 10.1038/362739a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000052
DA 2026-03-10
ER

PT J
AU LIU, QL
   WANG, JK
   ZEWAIL, AH
AF LIU, QL
   WANG, JK
   ZEWAIL, AH
TI FEMTOSECOND DYNAMICS OF DISSOCIATION AND RECOMBINATION IN SOLVENT CAGES
SO NATURE
LA English
DT Article
ID i2-(co2)n cluster ions; geminate recombination; photo-dissociation; b-state; photodissociation; i2; spectroscopy; iodine; fragmentation; transitions
AB FOR chemical reactions in solution, the solvent exerts an important influence on the elementary processes of bond making and breaking. The solvent may, for example, enhance bond formation by trapping reactive species in a 'solvent cage' on the reaction timescale1, or it may act as a 'chaperone' that stabilizes energetic species2. Ultrafast reaction dynamics in solvent shells can be probed using laser spectroscopic techniques developed to resolve atomic motion on the femtosecond (fs) timescale3. Here we report on a study of the femtosecond dynamics of the dissociation of neutral iodine molecules encaged in clusters of around 40-150 argon atoms, which form a solvent shell4-6. We find that, when dissociation occurs from the A-type excited electronic state of I2, the iodine atoms exhibit coherent motion on a sub-picosecond (<10(-12) s) timescale, rebounding from the 'frozen' solvent cage and recombining. The 'hot' I2 molecule is then cooled over by collisions with the argon atoms. We provide support for these interpretations using molecular-dynamics simulations. Dissociation from the B state, meanwhile, involves slower bond-breaking and slower recombination of the fragments-there is no coherent 'rebound' from the solvent cage. The dissociation pathway therefore depends critically on the timescale of bond breaking relative to that of solvent rearrangement.
RP LIU, QL (corresponding author), CALTECH,ARTHUR AMOS NOYES LAB CHEM PHYS,PASADENA,CA 91125, USA.
NR 32
TC 160
Z9 177
U1 0
U2 40
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 427
EP 430
DI 10.1038/364427a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000049
DA 2026-03-10
ER

PT J
AU HENDRICK, RL
   PREGITZER, KS
AF HENDRICK, RL
   PREGITZER, KS
TI PATTERNS OF FINE ROOT MORTALITY IN 2 SUGAR MAPLE FORESTS
SO NATURE
LA English
DT Article
ID carbon allocation; deciduous forest; nitrogen budgets; soil-temperature; organic-matter; ecosystems; turnover; biomass; productivity; respiration
AB MUCH of the carbon assimilated by plants is allocated to fine root production1-5, and the amount of carbon and nutrients subsequently returned to the soil from fine root turnover equals or surpasses that returned through leaf litter in many forests6-9. Unfortunately, limitations in traditional methods of studying roots have prevented us from thoroughly understanding the dynamic nature of fine root mortality in most forests, and better measurements of fine root longevity are needed to quantify and model more accurately ecosystem carbon and nutrient budgets8-11. We used minirhizotrons12,13 to follow the mortality of contemporaneous fine root cohorts in two sugar maple (Acer saccharum Marsh.) forests located 80 km apart (north-south) during 1989 and 1990. We report here that roots in the northern forest consistently lived the longest, principally owing to greater rates of mortality early in the life of roots at the southern site. Differences in site factors suggest that warmer soil temperatures seem to be associated with the more rapid death of roots at the southern site.
C1 MICHIGAN STATE UNIV, DEPT FORESTRY, E LANSING, MI 48824 USA.
C3 Michigan State University
NR 29
TC 217
Z9 293
U1 1
U2 88
PU NATURE RESEARCH
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 59
EP 61
DI 10.1038/361059a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800046
DA 2026-03-10
ER

PT J
AU NICOLAOU, KC
   RIEMER, C
   KERR, MA
   RIDEOUT, D
   WRASIDLO, W
AF NICOLAOU, KC
   RIEMER, C
   KERR, MA
   RIDEOUT, D
   WRASIDLO, W
TI DESIGN, SYNTHESIS AND BIOLOGICAL-ACTIVITY OF PROTAXOLS
SO NATURE
LA English
DT Article
ID water-soluble prodrugs; antitumor-activity; taxol; cells; microtubules; agents; assay
AB TAXOL1-6 is a product isolated from the Pacific yew tree (Taxus brevifolia) and is a potent microtubule-stabilizing agent which has recently been approved for treatment of otherwise intractable ovarian cancer. Despite taxol's therapeutic promise, its aqueous insolubility (<0.004 mg ml-1) hampers its clinical application. Here we report the design, synthesis and biological activity of a series of taxol-releasing compounds (protaxols) with improved pharmacological properties. These prodrugs were designed to increase their aqueous solubility and allow for taxol release under basic or physiological conditions. We demonstrate the stability of these prodrugs at pH less-than-or-equal-to 7 and their ability to release taxol in a basic medium. Taxol-like microtubule-stabilizing activity7-9 appears after the release of taxol. In vitro these prodrugs have cytotoxic properties against tumour cell lines comparable to those of taxol; moreover, human plasma catalyses the release of active taxol. These protaxols have greater potential as anticancer agents than the parent compounds taxol and taxotere (Fig. 1a).
C1 UNIV CALIF SAN DIEGO, DEPT CHEM, LA JOLLA, CA 92093 USA.
   SCRIPPS RES INST, DEPT MOLEC BIOL, LA JOLLA, CA 92037 USA.
   SCRIPPS RES INST, DRUG DISCOVERY UNIT, LA JOLLA, CA 92037 USA.
C3 University of California System; University of California San Diego; Scripps Research Institute; Scripps Research Institute
RP NICOLAOU, KC (corresponding author), SCRIPPS RES INST, DEPT CHEM, 10666 N TORREY PINES RD, LA JOLLA, CA 92037 USA.
NR 17
TC 123
Z9 169
U1 0
U2 39
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 464
EP 466
DI 10.1038/364464a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000061
PM 8101355
DA 2026-03-10
ER

PT J
AU OU, WJ
   CAMERON, PH
   THOMAS, DY
   BERGERON, JJM
AF OU, WJ
   CAMERON, PH
   THOMAS, DY
   BERGERON, JJM
TI ASSOCIATION OF FOLDING INTERMEDIATES OF GLYCOPROTEINS WITH CALNEXIN DURING PROTEIN MATURATION
SO NATURE
LA English
DT Article
ID rough endoplasmic-reticulum; newly synthesized proteins; influenza hemagglutinin; intracellular-transport; linked oligosaccharides; molecular chaperone; alpha-subunit; complex; glycosylation; secretion
AB Calnexin, an endoplasmic reticulum transmembrane protein, represents a new type of molecular chaperone that selectively associates in a transient fashion with newly synthesized monomeric glycoproteins in HepG2 cells. Calnexin only recognizes glycoproteins when they are incompletely folded. Dissociation of glycoproteins from calnexin occurs at different rates and is related to the time taken for their folding, which may then initiate their differential transport rates from the endoplasmic reticulum.
C1 MCGILL UNIV,DEPT BIOL,MONTREAL H3A 2B2,QUEBEC,CANADA.
   NATL RES COUNCIL CANADA,BIOTECHNOL RES INST,EUKARYOT GENET GRP,MONTREAL H4P 2R2,PQ,CANADA.
C3 McGill University; National Research Council Canada
RP OU, WJ (corresponding author), MCGILL UNIV,DEPT ANAT & CELL BIOL,MONTREAL H3A 2B2,QUEBEC,CANADA.
NR 35
TC 532
Z9 582
U1 1
U2 19
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 771
EP 776
DI 10.1038/364771a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100046
PM 8102790
DA 2026-03-10
ER

PT J
AU GUBBINS, D
   KELLY, P
AF GUBBINS, D
   KELLY, P
TI PERSISTENT PATTERNS IN THE GEOMAGNETIC-FIELD OVER THE PAST 2.5 MYR
SO NATURE
LA English
DT Article
AB HISTORICAL geomagnetic measurements covering the past 400 years reveal a symmetrical pattern of four relatively stationary flux concentrations ('lobes') at the surface of the liquid core and regions of rapid change extending from the Atlantic to the Indian Ocean1. Palaeomagnetic data define a time-average over several thousand years2 which might reflect the stationary parts of the present field, but unfortunately the historical record is too short to provide a satisfactory average3. Here we model palaeomagnetic directions from the past 2.5 Myr using the same methods as for modern data4, and find the two northern lobes in the same position as today, over Arctic Canada and Siberia. In southern regions, by contrast, the field appears to have been smoothed out, as might be expected from the current rapid secular variation1. We propose that the present geomagnetic field morphology and pattern of secular variation have persisted for several million years, as would occur if the solid mantle controls flow at the top of the core.
RP GUBBINS, D (corresponding author), UNIV LEEDS,DEPT EARTH SCI,LEEDS LS2 9JT,W YORKSHIRE,ENGLAND.
NR 15
TC 119
Z9 122
U1 1
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 829
EP 832
DI 10.1038/365829a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100047
DA 2026-03-10
ER

PT J
AU HARADA, A
   LI, J
   KAMACHI, M
AF HARADA, A
   LI, J
   KAMACHI, M
TI SYNTHESIS OF A TUBULAR POLYMER FROM THREADED CYCLODEXTRINS
SO NATURE
LA English
DT Article
AB MUCH attention has been focused recently on the design and fabrication of large-scale molecular structures1. Carbon nanotubes formed by an arc-discharge method2,3 have attracted particular attention. These tubes range from about 1 to 30 nanometres in diameter and a micrometre or so in length. To construct smaller tubes, direct chemical synthesis may be a more convenient approach. The cyclic oligomers of glucose known as cyclodextrins (CDs) would seem to be ideal candidates for the components of a molecular tube: they contain cylindrical cavities about 0.7 nm deep, with diameters of 0.45 nm, 0.7 nm and 0.85 nm for alpha-CD, beta-CD and gamma-CD respectively4. Lehn has recently reported the use of 'bouquet molecules' built from beta-CD with long side chains as artificial ion channels5. We have previously prepared rotaxane super-molecules in which CDs are threaded on a polymer chain, and we6 and others7,8, have reported polyrotaxanes with many threaded CDs. Here we report the crosslinking of adjacent CD units in a polyrotaxane to create a molecular tube. By removing the bulky ends of the polymer thread, the tube can be unthreaded and can act as a host for reversible binding of small molecules.
RP HARADA, A (corresponding author), OSAKA UNIV,FAC SCI,DEPT MACROMOLEC SCI,TOYONAKA,OSAKA 560,JAPAN.
NR 8
TC 593
Z9 636
U1 3
U2 128
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 516
EP 518
DI 10.1038/364516a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700049
DA 2026-03-10
ER

PT J
AU TIITINEN, H
   SINKKONEN, J
   REINIKAINEN, K
   ALHO, K
   LAVIKAINEN, J
   NAATANEN, R
AF TIITINEN, H
   SINKKONEN, J
   REINIKAINEN, K
   ALHO, K
   LAVIKAINEN, J
   NAATANEN, R
TI SELECTIVE ATTENTION ENHANCES THE AUDITORY 40-HZ TRANSIENT-RESPONSE IN HUMANS
SO NATURE
LA English
DT Article
ID evoked-potentials
AB STUDIES of human auditory1-3 and somatosensory3 modalities have shown that there is an oscillatory response in the gamma-band (at about 40 Hz) frequency which is elicited by either steady state1-3 or transient4 stimulation. The auditory 40-Hz response is generated at least partially in the auditory cortex4,5 as a result of thalamocortical interaction6 and may serve perceptual integration7,8 and conscious perception9. A connection to selective attention has been implied in human10 and animal11 studies, although the evidence is inconclusive12. Moreover, fundamental differences between the human and animal 40-Hz responses13 prohibit generalization. Furthermore, most experiments have used steady-state stimulation during which the brain does not regain its resting state between stimuli as it does when transient stimulation is used14. Here we study the effect of selective attention on the auditory gamma-band (40-Hz) transient response using subjects listening to tone pips presented in one ear while ignoring a concurrent sequence of tone pips in the other ear. The 40-Hz response was larger when subjects paid attention to stimuli rather than ignored them. This attention effect was most pronounced over the frontal and central scalp areas. Our results demonstrate a physiological correlate of selective attention in the 40-Hz transient response in humans.
RP TIITINEN, H (corresponding author), UNIV HELSINKI,DEPT PSYCHOL,COGNIT PSYCHOPHYSIOL RES UNIT,RITARIKATU 5,SF-00170 HELSINKI 17,FINLAND.
NR 22
TC 514
Z9 574
U1 0
U2 28
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 59
EP 60
DI 10.1038/364059a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800056
PM 8316297
DA 2026-03-10
ER

PT J
AU OLSEN, B
   JAENSON, TGT
   NOPPA, L
   BUNIKIS, J
   BERGSTROM, S
AF OLSEN, B
   JAENSON, TGT
   NOPPA, L
   BUNIKIS, J
   BERGSTROM, S
TI A LYME BORRELIOSIS CYCLE IN SEABIRDS AND IXODES-URIAE TICKS
SO NATURE
LA English
DT Article
ID monoclonal-antibody; burgdorferi
AB THE Lyme disease spirochaete, Borrelia burgdorferi s.l., is the only Borrelia known to infect both mammals and birds1. The main vertebrate reservoirs of B. burgdorferi are thought to be various small and intermediate size mammals2, but the importance of birds as a reservoir has not been thoroughly explored. In the Northern and Southern Hemispheres the seabird tick, Ixodes uriae, is prevalent and closely associated with many species of colony-nesting marine birds3. Here we report the presence of spirochaetes, demonstrated by immunofluorescent assay, by polymerase chain reaction and in culture. in I. uriae infesting razorbills on an island in the Baltic Sea. This island is free from mammals. The protein profile of the spirochaetes and the sequences of their flagellin and ospA genes are identical to those of the Lyme disease spirochaete, Borrelia burgdorferi s.l., previously isolated from I. ricinus on a nearby island. In biopsies from the foot web of razorbills, B. burgdorferi-specific DNA was detected after amplification by polymerase chain reaction. Our results suggest that birds play an important part in the maintenance of B. burgdorferi and that mammals may not be a prerequisite for its life cycle.
C1 UMEA UNIV,DEPT MICROBIOL,S-90187 UMEA,SWEDEN.
   UMEA UNIV,DEPT INFECT DIS,S-90187 UMEA,SWEDEN.
   UNIV UPPSALA,DEPT ZOOL,S-75122 UPPSALA,SWEDEN.
C3 Umea University; Umea University; Uppsala University
NR 16
TC 174
Z9 190
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 340
EP 342
DI 10.1038/362340a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600059
PM 8455718
DA 2026-03-10
ER

PT J
AU BRUGGEMANN, A
   PARDO, LA
   STUHMER, W
   PONGS, O
AF BRUGGEMANN, A
   PARDO, LA
   STUHMER, W
   PONGS, O
TI ETHER-A-GO-GO ENCODES A VOLTAGE-GATED CHANNEL PERMEABLE TO K+ AND CA2+ AND MODULATED BY CAMP
SO NATURE
LA English
DT Article
ID potassium channel; xenopus oocytes; drosophila-eag; ion channels; expression; mutations; currents; system
AB THE Drosophila ether-a-go-go (eag) mutant is responsible for altered potassium currents in excitable tissue1. These mutants exhibit spontaneous, repetitive firing of action potentials in the motor axons of larval neuromuscular junctions2. The eag gene encodes a polypeptide3 that shares sequence similarities with several different ionic channel proteins, including voltage-gated potassium channels-, an inward rectifier4,5 as well as cyclic-nucleotide-gated channels6. These formal similarities in the derived primary sequences indicate that eag polypeptides might express a new type of ion channel. Here we report the expression by eag RNA in Xenopus oocytes of such a channel which incorporates properties of both voltage- and ligand-gated channels. The permeability of these eag channels to potassium and calcium is dependent on voltage and cyclic AMP. The ability to mediate potassium-outward and calcium-inward currents endows this channel with properties likely to be important in the modulation of synaptic efficiency in both central and peripheral nervous systems.
C1 MAX PLANCK INST EXPTL MED, HERMANN REIN STR 3, D-37075 GOTTINGEN, GERMANY.
   ZMNH, INST NEURONALE SIGNALVERARBEITUNG, D-20246 HAMBURG, GERMANY.
   UNIV OVIEDO, DEPT BIOL FUNCT, E-33006 OVIEDO, SPAIN.
C3 Max Planck Society; University of Oviedo
NR 23
TC 199
Z9 221
U1 0
U2 7
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 445
EP 448
DI 10.1038/365445a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300057
PM 7692301
DA 2026-03-10
ER

PT J
AU MOSHCHALKOV, VV
   GIELEN, L
   DHALLE, M
   VANHAESENDONCK, C
   BRUYNSERAEDE, Y
AF MOSHCHALKOV, VV
   GIELEN, L
   DHALLE, M
   VANHAESENDONCK, C
   BRUYNSERAEDE, Y
TI QUANTUM INTERFERENCE IN A MESOSCOPIC SUPERCONDUCTING LOOP
SO NATURE
LA English
DT Article
ID networks
AB THE classical superconducting quantum interference device (SQUID) is based on the Josephson effect1, and usually consists of a macroscopic superconducting loop with two artificial weak links (Josephson junctions) through which the supercurrent passes by quantum-mechanical tunnelling. Fink et al.2 proposed a new type of SQUID based on a homogeneous mesoscopic superconducting loop, in which interference between the supercurrents passing through the two halves of the ring results in a critical current that varies with the applied magnetic field in an oscillatory manner. Here we describe the experimental observation of these oscillations in a mesoscopic superconducting aluminum loop without artificial weak links. In this new type of quantum interferometer, 'weak-link' regions with a strongly reduced superconducting order parameter appear periodically at half-integer magnetic flux quanta owing to the interplay between the shielding and transport currents in the loop.
RP MOSHCHALKOV, VV (corresponding author), KATHOLIEKE UNIV LEUVEN, VASTE STOF FYS MAGNETISME LAB, B-3001 LOUVAIN, BELGIUM.
NR 12
TC 56
Z9 59
U1 0
U2 21
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 617
EP 620
DI 10.1038/361617a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600057
DA 2026-03-10
ER

PT J
AU HISATAKE, K
   ROEDER, RG
   HORIKOSHI, M
AF HISATAKE, K
   ROEDER, RG
   HORIKOSHI, M
TI FUNCTIONAL DISSECTION OF TFIIB DOMAINS REQUIRED FOR TFIIB-TFIID-PROMOTER COMPLEX-FORMATION AND BASAL TRANSCRIPTION ACTIVITY
SO NATURE
LA English
DT Article
ID rna polymerase-ii; preinitiation complex; tata factor; factor atf; initiation; mutations; subunit
AB THE protein TFIIB is a general transcription initiation factor1 that interacts with a promoter complex (D.DNA) containing the TATA-binding subunit (TFIIDtau, or TBP) of TFIID to facilitate subsequent interaction with RNA polymerase II (ref. 2) through the associated TFIIF (ref. 3). The potential bridging function2,4 of TFIIB raises the possibility of two structural domains and emphasizes the importance of TFIIB structure-function studies for a further understanding of preinitiation complex assembly and function1. Here we show that human TFIIB (refs 5,6) is comprised of functionally distinct N- and C-terminal domains. The C-terminal domain, containing the direct repeats and associated bask regions, is necessary and sufficient for interaction with the D.DNA complex. By contrast, the N-terminal domain that is dispensable for formation of the TFIIDtau-TFIIB-promoter (D.B.DNA) complex is required for subsequent events leading to basal transcription initiation. On the basis of these results, we discuss structural and functional similarities between TFIIB and TFIIDtau, which have similar structural organization and motifs5.
C1 ROCKEFELLER UNIV, BIOCHEM & MOLEC BIOL LAB, NEW YORK, NY 10021 USA.
   UNIV TOKYO, INST MOLEC & CELLULAR BIOSCI, BUNKYO KU, TOKYO 113, JAPAN.
C3 Rockefeller University; University of Tokyo
NR 27
TC 72
Z9 73
U1 0
U2 2
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 744
EP 747
DI 10.1038/363744a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900063
PM 8515820
DA 2026-03-10
ER

PT J
AU CLEMENS, SC
   FARRELL, JW
   GROMET, LP
AF CLEMENS, SC
   FARRELL, JW
   GROMET, LP
TI SYNCHRONOUS CHANGES IN SEAWATER STRONTIUM ISOTOPE COMPOSITION AND GLOBAL CLIMATE
SO NATURE
LA English
DT Article
ID ice ages; stratigraphy; ocean; rates
AB THE Sr-87/Sr-86 ratio of sea water has increased gradually over the Past 40 Myr, suggesting a concomitant increase in global chemical weathering rates1-6. Recently, Dia et al.7 analysed a 250-kyr Sr-87/Sr-86 record, and found superimposed on this gradual increase higher-frequency Sr-87/Sr-86 variations which appeared to follow a 100-kyr cycle; this periodicity corresponds to one of the prominent cycles in the Earth's orbital parameters, which are known to modulate the patterns of solar insolation and hence climate8-10. The resolution of this record was, however, insufficient to establish the phase relationship between the Sr-87/Sr-86 variations and global climate cycles. Here we present a high-resolution seawater Sr-87/Sr-86 record spanning the past 450 kyr. We rind that maxima and minima in Sr-87/Sr-86 coincide with minima and maxima, respectively, in continental ice volume (from the SPECMAP oxygen isotope record20), apparently suggesting that there was less chemical weathering in arid glacial periods than in the more humid interglacials. During glacial-interglacial transitions, however, seawater Sr-87/Sr-86 changes at a rate of approximately 1 p.p.m. kyr-1, approximately three times that evaluated by Dia et al.7. Mass-balance calculations illustrate that simple changes in modern chemical weathering regimes cannot fully account for such rapid changes, suggesting that we need to revise current ideas about strontium reservoirs and the mechanisms for exchange between them.
RP CLEMENS, SC (corresponding author), BROWN UNIV,PROVIDENCE,RI 02912, USA.
NR 33
TC 54
Z9 61
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 607
EP 610
DI 10.1038/363607a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900048
DA 2026-03-10
ER

PT J
AU VANTILBEURGH, H
   EGLOFF, MP
   MARTINEZ, C
   RUGANI, N
   VERGER, R
   CAMBILLAU, C
AF VANTILBEURGH, H
   EGLOFF, MP
   MARTINEZ, C
   RUGANI, N
   VERGER, R
   CAMBILLAU, C
TI INTERFACIAL ACTIVATION OF THE LIPASE PROCOLIPASE COMPLEX BY MIXED MICELLES REVEALED BY X-RAY CRYSTALLOGRAPHY
SO NATURE
LA English
DT Article
ID human lipoprotein-lipase; inhibitor complex; catalysis; family; model; site
AB The three-dimensional structure of the lipase-procolipase complex, co-crystallized with mixed micelles of phosphatidylcholine and bile salt, has been determined at 3 angstrom resolution by X-ray crystallography. The lid, a surface helix covering the catalytic triad of lipase, adopts a totally different conformation which allows phospholipid to bind to the enzyme's active site. The open lid is an essential component of the active site and interacts with procolipase. Together they form the lipid-water interface binding site. This reorganization of the lid structure provokes a second drastic conformational change in an active site loop, which in its turn creates the oxyanion hole (induced fit).
C1 FAC SCI ST CHARLES, INST CHIM BIOL, F-13331 MARSEILLE, FRANCE.
   CNRS, GDR1000, LIPOLYSE ENZYMAT LAB, F-13402 MARSEILLE 9, FRANCE.
C3 Centre National de la Recherche Scientifique (CNRS)
RP VANTILBEURGH, H (corresponding author), FAC MED NORD, CNRS, LCCMB, BLVD P DRAMARD, F-13326 MARSEILLE 15, FRANCE.
NR 26
TC 653
Z9 690
U1 0
U2 107
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 814
EP 820
DI 10.1038/362814a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300047
PM 8479519
DA 2026-03-10
ER

PT J
AU GEHRING, K
   LEROY, JL
   GUERON, M
AF GEHRING, K
   LEROY, JL
   GUERON, M
TI A TETRAMERIC DNA-STRUCTURE WITH PROTONATED CYTOSINE.CYTOSINE BASE-PAIRS
SO NATURE
LA English
DT Article
ID acid
AB OLIGOMERS containing tracts of-cytidine form hemiprotonated base pairs at acid pH and have been considered to be double-stranded. We have solved the structure of the DNA oligomer 5'-d(TCCCCC) at acid pH and find that it is a four-stranded complex in which two base-paired parallel-stranded duplexes are intimately associated, with their base pairs fully intercalated. The relative orientation of the duplexes is antiparallel, so that each base pair is face-to-face with its neighbours. The NMR spectrum displays only six spin systems, showing that the structure is highly symmetrical on the NMR timescale; the four strands are equivalent. A model derived by energy minimization and constrained molecular dynamics shows excellent compatibility with the observed nuclear Overhauser effects (NOEs) particularly for the very unusual inter-residue sugar-sugar NOEs H1'-H1', H1'-H2'' and H1'-H4'. These NOEs are probably diagnostic for such tetrameric structures.
C1 CNRS, URA D1254, F-91128 PALAISEAU, FRANCE.
   ECOLE POLYTECH, BIOPHYS GRP, F-91128 PALAISEAU, FRANCE.
C3 Centre National de la Recherche Scientifique (CNRS); Institut Polytechnique de Paris; Ecole Polytechnique; Institut Polytechnique de Paris; Ecole Polytechnique
NR 28
TC 1082
Z9 1205
U1 3
U2 256
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 561
EP 565
DI 10.1038/363561a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900056
PM 8389423
DA 2026-03-10
ER

PT J
AU SMITH, WC
   KNECHT, AK
   WU, M
   HARLAND, RM
AF SMITH, WC
   KNECHT, AK
   WU, M
   HARLAND, RM
TI SECRETED NOGGIN PROTEIN MIMICS THE SPEMANN ORGANIZER IN DORSALIZING XENOPUS MESODERM
SO NATURE
LA English
DT Article
ID messenger-rna; insitu hybridization; laevis embryos; localization; expression; axis
AB A DORSALIZING signal acts during gastrulation to change the specification of lateral mesodermal tissues from ventral (blood, mesenchyme) to more dorsal fates (muscle, heart, pronephros)1-3. This signal, from Spemann's organizer, cannot be mimicked by the mesoderm inducers activin and fibroblast growth factor2. The gene noggin is expressed in the organizer 4, and could be the dorsalizing signal. Here we show that soluble noggin protein added to ventral marginal zones during gastrulation induces muscle, but that activin does not. Dorsal pattern can be partially rescued in ventralized embryos by injection of a plasmid that expresses noggin during gastrulation. The results suggest that the noggin product may be the dorsalizing signal from the organizer.
C1 UNIV CALIF BERKELEY,DEPT MOLEC & CELL BIOL,DIV BIOCHEM & MOLEC BIOL,401 BARKER HALL,BERKELEY,CA 94720.
C3 University of California System; University of California Berkeley
NR 20
TC 338
Z9 378
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 547
EP 549
DI 10.1038/361547a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400064
PM 8429909
DA 2026-03-10
ER

PT J
AU BOCK, Y
   AGNEW, DC
   FANG, P
   GENRICH, JF
   HAGER, BH
   HERRING, TA
   HUDNUT, KW
   KING, RW
   LARSEN, S
   MINSTER, JB
   STARK, K
   WDOWINSKI, S
   WYATT, FK
AF BOCK, Y
   AGNEW, DC
   FANG, P
   GENRICH, JF
   HAGER, BH
   HERRING, TA
   HUDNUT, KW
   KING, RW
   LARSEN, S
   MINSTER, JB
   STARK, K
   WDOWINSKI, S
   WYATT, FK
TI DETECTION OF CRUSTAL DEFORMATION FROM THE LANDERS EARTHQUAKE SEQUENCE USING CONTINUOUS GEODETIC MEASUREMENTS
SO NATURE
LA English
DT Article
ID global positioning system; phase ambiguity resolution; california; faults; shear
AB THE measurement of crustal motions in tectonically active regions is being performed increasingly by the satellite-based Global Positioning System (GPS)1,2, which offers considerable advantages over conventional geodetic techniques3,4. Continuously operating GPS arrays with ground-based receivers spaced tens of kilometres apart have been established in central Japan5,6 and southern California to monitor the spatial and temporal details of crustal deformation. Here we report the first measurements for a major earthquake by a continuously operating GPS network, the Permanent GPS Geodetic Array (PGGA)7-9 in southern California. The Landers (magnitude M(w) of 7.3) and Big Bear (M(w) 6.2) earthquakes of 28 June 1992 were monitored by daily observations. Ten weeks of measurements, centred on the earthquake events, indicate significant coseismic motion at all PGGA sites, significant post-seismic motion at one site for two weeks after the earthquakes, and no significant preseismic motion. These measurements demonstrate the potential of GPS monitoring for precise detection of precursory and aftershock seismic deformation in the near and far field.
C1 MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139.
   US GEOL SURVEY,PASADENA,CA 91106.
   LAWRENCE LIVERMORE NATL LAB,DIV SCI SOFTWARE,LIVERMORE,CA 94550.
C3 Massachusetts Institute of Technology (MIT); United States Department of the Interior; United States Geological Survey; United States Department of Energy (DOE); Lawrence Livermore National Laboratory
RP BOCK, Y (corresponding author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,INST GEOPHYS & PLANETARY PHYS,LA JOLLA,CA 92093, USA.
NR 24
TC 95
Z9 108
U1 1
U2 14
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 337
EP 340
DI 10.1038/361337a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000051
DA 2026-03-10
ER

PT J
AU ALDROVANDI, GM
   FEUER, G
   GAO, LY
   JAMIESON, B
   KRISTEVA, M
   CHEN, ISY
   ZACK, JA
AF ALDROVANDI, GM
   FEUER, G
   GAO, LY
   JAMIESON, B
   KRISTEVA, M
   CHEN, ISY
   ZACK, JA
TI THE SCID-HU MOUSE AS A MODEL FOR HIV-1 INFECTION
SO NATURE
LA English
DT Article
ID acquired immunodeficiency syndrome; lymphocytes
AB DURING normal fetal ontogeny, one of the first organs to harbour CD4-positive cells is the thymus1. This organ could therefore be one of the earliest targets infected by human immunodeficiency virus type 1 (HIV-1) in utero. HIV-1-infected cells and pathological abnormalities of the thymus have been seen in HIV-1-infected adults and children, and in some fetuses aborted from infected women2-5. Studies of HIV-1 pathogenesis have been hampered by lack of a suitable animal model system. Here we use the SCID-hu mouse6 as a model to investigate the effect of virus infection on human tissue. The mouse is homozygous for the severe combined immunodeficiency (SCID) defect7,8. The model is constructed by implanting human fetal fiver and thymus under the mouse kidney capsule. A conjoint human organ develops, which allows normal maturation of human thymocytes. After direct inoculation of HIV-1 into these implants, we observed severe depletion of human CD4-bearing cells within a few weeks of infection. This correlated with increasing virus load in the implants. Thus the SCID-hu mouse may be a useful in vivo system for the study of HIV-1-induced pathology.
C1 UNIV CALIF LOS ANGELES, SCH MED, DEPT MED, DIV HEMATOL ONCOL, LOS ANGELES, CA 90024 USA.
   JONSSON COMPREHENS CANC CTR, LOS ANGELES, CA 90024 USA.
   UNIV CALIF LOS ANGELES, HARBOR MED CTR, DEPT PEDIAT, DIV INFECT DIS, TORRANCE, CA 90509 USA.
   UNIV CALIF LOS ANGELES, SCH MED, DEPT MICROBIOL & IMMUNOL, LOS ANGELES, CA 90024 USA.
C3 University of California System; University of California Los Angeles; University of California Los Angeles Medical Center; David Geffen School of Medicine at UCLA; UCLA Jonsson Comprehensive Cancer Center; University of California System; University of California Los Angeles; University of California Los Angeles Medical Center; University of California System; University of California Los Angeles; University of California Los Angeles Medical Center; David Geffen School of Medicine at UCLA
NR 19
TC 271
Z9 296
U1 1
U2 7
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 732
EP 736
DI 10.1038/363732a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900059
PM 8515816
DA 2026-03-10
ER

PT J
AU SENGOR, AMC
   NATALIN, BA
   BURTMAN, VS
AF SENGOR, AMC
   NATALIN, BA
   BURTMAN, VS
TI EVOLUTION OF THE ALTAID TECTONIC COLLAGE AND PALEOZOIC CRUSTAL GROWTH IN EURASIA
SO NATURE
LA English
DT Article
ID continental growth; tien-shan; pacific
AB A new tectonic model, postulating the growth of giant subduction-accretion complexes along a single magmatic arc now found contorted between Siberia and Baltica, shows that Asia grew by 5.3 million square kilometres during the Palaeozoic era. Half of this growth may have occurred by the addition of juvenile crust newly extracted from the mantle, supporting models of considerable continental growth continuing throughout the Phanerozoic eon.
RP SENGOR, AMC (corresponding author), ITU,MADEN FAK,JEOLOJI BOLUMU,80626 ISTANBUL,TURKEY.
NR 83
TC 3868
Z9 4737
U1 12
U2 378
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 299
EP 307
DI 10.1038/364299a0
PG 9
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000046
DA 2026-03-10
ER

PT J
AU CRAIG, VSJ
   NINHAM, BW
   PASHLEY, RM
AF CRAIG, VSJ
   NINHAM, BW
   PASHLEY, RM
TI EFFECT OF ELECTROLYTES ON BUBBLE COALESCENCE
SO NATURE
LA English
DT Article
ID hydrophobic interaction; liquid-films; surfaces; drainage
AB THE foaminess of ocean waves, relative to fresh water, has long been attributed to the effect of salts in reducing bubble coalescence9. This phenomenon is exploited in extraction processes using froth flotation1, in which the extraction efficiency increases as the bubble size gets smaller. But whereas the bubble-stabilizing effect of surfactants is well understood, the effect of salts is not; the fact that salts decrease the surface tension of water and that they are desorbed from the air-water interface would, if anything, be expected to destabilize bubbles. Here we report the results of experiments conducted to study the stabilization of bubbles by salts. We find that bubble coalescence is inhibited by some salts whereas others have no effect and that this inhibition occurs only upon the 'matching' of a two-valued empirical property assigned to each anion and cation. We believe these observations can be explained only by the local influence of the ions on water structure, possibly in a way related to the hydrophobic interaction2-8.
C1 AUSTRALIAN NATL UNIV,DEPT APPL MATH,CANBERRA,ACT 2601,AUSTRALIA.
C3 Australian National University
RP CRAIG, VSJ (corresponding author), AUSTRALIAN NATL UNIV,DEPT CHEM,POB 4,CANBERRA,ACT 2601,AUSTRALIA.
NR 13
TC 292
Z9 325
U1 0
U2 71
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 317
EP 319
DI 10.1038/364317a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000050
DA 2026-03-10
ER

PT J
AU ALCOCK, C
   AKERLOF, CW
   ALLSMAN, RA
   AXELROD, TS
   BENNETT, DP
   CHAN, S
   COOK, KH
   FREEMAN, KC
   GRIEST, K
   MARSHALL, SL
   PARK, HS
   PERLMUTTER, S
   PETERSON, BA
   PRATT, MR
   QUINN, PJ
   RODGERS, AW
   STUBBS, CW
   SUTHERLAND, W
AF ALCOCK, C
   AKERLOF, CW
   ALLSMAN, RA
   AXELROD, TS
   BENNETT, DP
   CHAN, S
   COOK, KH
   FREEMAN, KC
   GRIEST, K
   MARSHALL, SL
   PARK, HS
   PERLMUTTER, S
   PETERSON, BA
   PRATT, MR
   QUINN, PJ
   RODGERS, AW
   STUBBS, CW
   SUTHERLAND, W
TI POSSIBLE GRAVITATIONAL MICROLENSING OF A STAR IN THE LARGE MAGELLANIC CLOUD
SO NATURE
LA English
DT Article
ID dark matter; galaxy; mass; halo
AB THERE is now abundant evidence for the presence of large quantities of unseen matter surrounding normal galaxies, including our own1,2. The nature of this 'dark matter' is unknown, except that it cannot be made of normal stars, dust or gas, as they would be easily detected. Exotic particles such as axions, massive neutrinos or other weakly interacting massive particles (collectively known as WIMPs) have been proposed3,4, but have yet to be detected. A less exotic alternative is normal matter in the form of bodies with masses ranging from that of a large planet to a few solar masses. Such objects, known collectively as massive compact halo objects5 (MACHOs), might be brown dwarfs or 'jupiters' (bodies too small to produce their own energy by fusion), neutron stars, old white dwarfs or black holes. Paczynski6 suggested that MACHOs might act as gravitational microlenses, temporarily amplifying the apparent brightness of background stars in nearby galaxies. We are conducting a microlensing experiment to determine whether the dark matter halo of our Galaxy is made up of MACHOs. Here we report a candidate for such a microlensing event, detected by monitoring the light curves of 1.8 million stars in the Large Magellanic Cloud for one year. The light curve shows no variation for most of the year of data taking, and an upward excursion lasting over 1 month, with a maximum increase of approximately 2 mag. The most probable lens mass, inferred from the duration of the candidate lensing event, is approximately 0.1 solar mass.
C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720.
   AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,WESTON,ACT 2611,AUSTRALIA.
   UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106.
   UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093.
   UNIV MICHIGAN,DEPT PHYS,ANN ARBOR,MI 48109.
C3 University of California System; University of California Berkeley; Australian National University; University of California System; University of California Santa Barbara; University of California System; University of California San Diego; University of Michigan System; University of Michigan
RP ALCOCK, C (corresponding author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA.
NR 14
TC 735
Z9 764
U1 0
U2 23
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 621
EP 623
DI 10.1038/365621a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600049
DA 2026-03-10
ER

PT J
AU BARLOWE, C
   SCHEKMAN, R
AF BARLOWE, C
   SCHEKMAN, R
TI SEC12 ENCODES A GUANINE-NUCLEOTIDE-EXCHANGE FACTOR ESSENTIAL FOR TRANSPORT VESICLE BUDDING FROM THE ER
SO NATURE
LA English
DT Article
ID gtp-binding protein; adp-ribosylation factor; endoplasmic-reticulum; saccharomyces-cerevisiae; membrane glycoprotein; golgi-apparatus; brefeldin-a; yeast; ras; arf
AB IN yeast a type II integral membrane glycoprotein that is essential for transport vesicle budding from the endoplasmic reticulum (ER) is encoded by SEC12 (refs 1-3). SAR1 was discovered as a multi-copy copy suppressor of the sec12-1ts strain and encodes a GTPase of M(r) 21,000 (21K) also essential for vesicle budding from the ER4,5. Sar1 is a peripherally associated membrane protein which shows enhanced membrane binding in cells containing elevated levels of Sec12 protein (refs 6, 7). We show here that a purified fragment of Sec12 promotes guanine-nucleotide dissociation from Sar1 whereas the purified mutant Sec12-1 has only 15% of the wild-type activity. GTP hydrolysis by Sar1 is not enhanced by Sec12, but is stimulated more than 50-fold by a mixture of Sec12 and Sec23, a GTPase-activating protein specific for Sar1 (ref. 8). We propose that Sec12 catalyses Sar1 guanine-nucleotide exchange in a process that recruits Sar1 to a vesicle formation site on the ER membrane.
C1 UNIV CALIF BERKELEY,HOWARD HUGHES MED INST,DEPT MOLEC & CELL BIOL,BERKELEY,CA 94720.
C3 University of California System; University of California Berkeley; Howard Hughes Medical Institute
NR 28
TC 397
Z9 472
U1 0
U2 35
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 347
EP 349
DI 10.1038/365347a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600054
PM 8377826
DA 2026-03-10
ER

PT J
AU SELLEM, CH
   LECELLIER, G
   BELCOUR, L
AF SELLEM, CH
   LECELLIER, G
   BELCOUR, L
TI TRANSPOSITION OF A GROUP-II INTRON
SO NATURE
LA English
DT Article
ID podospora-anserina; mitochondrial plasmid; rna; dna; senescence; gene; protein; invitro
AB AMONG mobile genetic elements, self-splicing introns are of particular interest. They belong to either group I or group II depending on their three-dimensional structure1-3. Homing, the systematic intron invasion of an intronless gene when it encounters its homologous intron-bearing allele, is the only means for intron mobility so far demonstrated4. It depends on the activity of the intron-encoded protein and is very specific for the acceptor site4-7. Intron transposition, the transfer of an intron to a novel site, predicted on the basis of phylogenetic studies8,9 and in vitro reverse-splicing experiments, has been proposed to be responsible for evolutionary intron spreading2,10-14. Here we present results from polymerase chain reaction experiments consistent with transposition of a group II intron. This event is proposed to account for the site-specific deletion in the mitochondrial chromosome of the fungus Podospora anserina that is associated with the premature death syndrome15 and might also be involved in the senescence process16 affecting this species.
RP BELCOUR, L (corresponding author), CNRS,CTR GENET MOLEC,F-91198 GIF SUR YVETTE,FRANCE.
NR 30
TC 105
Z9 113
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 176
EP 178
DI 10.1038/366176a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600063
PM 8232558
DA 2026-03-10
ER

PT J
AU SIMON, L
   BOUSQUET, J
   LEVESQUE, RC
   LALONDE, M
AF SIMON, L
   BOUSQUET, J
   LEVESQUE, RC
   LALONDE, M
TI ORIGIN AND DIVERSIFICATION OF ENDOMYCORRHIZAL FUNGI AND COINCIDENCE WITH VASCULAR LAND PLANTS
SO NATURE
LA English
DT Article
ID arbuscular mycorrhizal fungi; glomaceae; glomales
AB AMONG the Eukaryota, the true fungi comprise four divisions (Chytridiomycota, Zymogomycota, Ascomycota and Basidiomycota) that constitute a natural group which is thought to have diverged about 1 billion (10(9)) years ago, believed also to be the time of divergence between metaphyta and metazoa lineages1. The endosymbionts responsible for the most prevalent plant root symbiosis, the vesicular-arbuscular mycorrhizae (VAM) or, more appropriately, arbuscular mycorrhizae, comprise 130 species of fungi classified in the Zygomycotina, order Glomales2-4. The arbuscular endomycorrhizae are considered to be ecologically important for most vascular plants5-8 in view of their beneficial effects on plant growth and survival. They are one of the few plant-fungus associations with a fossil record and may even have facilitated the origin of land flora. But the biochemical and genetic characterization of these microsymbionts has been hampered by the inability to grow them in pure culture. To investigate the origin and clarify the phylogenetic relationships of these organisms, we have sequenced ribosomal DNA genes from twelve species. Our phylogenetic analyses confirm the existence of three families within arbuscular fungi on the basis of morphological characters. We obtain approximate dates for the divergence of major branches on the phylogenetic tree. These include an estimate for the origin of VAM-like fungi of 353-462 Myr ago, which is consistent with the hypothesis that VAM were instrumental in the colonization of land by ancient plants.
C1 UNIV LAVAL, FAC MED, DEPT MICROBIOL, Ste Foy G1K 7P4, PQ, CANADA.
C3 Laval University
RP SIMON, L (corresponding author), UNIV LAVAL, FAC FORESTERIE & GEOMAT, CTR RECH BIOL FORESTIERE, Ste Foy G1K 7P4, PQ, CANADA.
NR 20
TC 495
Z9 588
U1 4
U2 173
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 67
EP 69
DI 10.1038/363067a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200059
DA 2026-03-10
ER

PT J
AU SCULPTOREANU, A
   SCHEUER, T
   CATTERALL, WA
AF SCULPTOREANU, A
   SCHEUER, T
   CATTERALL, WA
TI VOLTAGE-DEPENDENT POTENTIATION OF L-TYPE CA2+ CHANNELS DUE TO PHOSPHORYLATION BY CAMP-DEPENDENT PROTEIN-KINASE
SO NATURE
LA English
DT Article
ID skeletal-muscle fibers; calcium channels; ca-2+ current; contraction; frog; twitches; cells
AB THE force of contraction of motor units in skeletal muscle is graded by changing the discharge rate of motor neurons1, and cytosolic calcium transients are similarly increased2. During single twitches, contraction is not dependent on extracellular calcium3, and L-type Ca2+ channels may only function as voltage sensors for initiating Ca2+ release from the sarcoplasmic reticulum4-6. In contrast, forceful tetanic contractions triggered by action potentials at high frequency (20 to 200 Hz) are dependent on extracellular Ca2+ concentration and sensitive to L-type Ca2+ channel antagonists7-9, but the mechanism of regulation of contractile force is unknown. Here we report a large, voltage- and frequency-dependent potentiation of skeletal muscle L-type Ca2+ currents by trains of high-frequency depolarizing prepulses, which is caused by a shift in the voltage-dependence of channel activation to more negative membrane potentials and requires phosphorylation by cyclic AMP-dependent protein kinase in a voltage-dependent manner. This potentiation would substantially increase Ca2+ influx and contractile force in skeletal muscle fibres in response to tetanic stimuli.
RP SCULPTOREANU, A (corresponding author), UNIV WASHINGTON,DEPT PHARMACOL,SJ-30,SEATTLE,WA 98195, USA.
NR 21
TC 234
Z9 250
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 240
EP 243
DI 10.1038/364240a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300058
PM 8391648
DA 2026-03-10
ER

PT J
AU PAPADAKIS, IE
   LAWRENCE, A
AF PAPADAKIS, IE
   LAWRENCE, A
TI QUASI-PERIODIC OSCILLATIONS IN X-RAY-EMISSION FROM THE SEYFERT-GALAXY NGC5548
SO NATURE
LA English
DT Article
ID optical observations; accretion disk; variability; ngc-5548; spectrum; mass
AB EFFORTS to use the variability of X-ray emission from active galactic nuclei (AGNs) as a diagnostic of physical processes in the unresolvable cores have been hampered by the discovery1,2 that the variable emission has a 'red noise' character, which seems to indicate the absence of any preferred timescale. The only exception is the claim of a precise periodicity in emission from NGC6814 3. Here we analyse archival Exosat observations of the bright Seyfert galaxy NGC5548, and find in the power spectrum a broad peak corresponding to quasi-periodic oscillations (QPOs) with period of approximately 500 s. Both the frequency and magnitude of the QPOs vary systematically with total X-ray luminosity. Similar behaviour has been seen in compact galactic X-ray binaries, and we suggest that intensity-correlated QPOs may be a generic feature of accretion onto a compact object. If the QPOs in NGC5548 derive from instability or variability in an accretion disc around a black hole, the black hole mass can be only a few hundred thousand solar masses, an uncomfortably small number for most AGN models.
RP PAPADAKIS, IE (corresponding author), QUEEN MARY & WESTFIELD COLL,DEPT PHYS,MILE END RD,LONDON E1 4NS,ENGLAND.
NR 20
TC 34
Z9 35
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 233
EP 236
DI 10.1038/361233a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400049
DA 2026-03-10
ER

PT J
AU SCHEDL, A
   MONTOLIU, L
   KELSEY, G
   SCHUTZ, G
AF SCHEDL, A
   MONTOLIU, L
   KELSEY, G
   SCHUTZ, G
TI A YEAST ARTIFICIAL CHROMOSOME COVERING THE TYROSINASE GENE CONFERS COPY NUMBER-DEPENDENT EXPRESSION IN TRANSGENIC MICE
SO NATURE
LA English
DT Article
ID mouse tyrosinase; albino mutation; large inserts; human dna; library; cloning; cells
AB EXPRESSION of transgenes in mice often fails to follow the normal temporal and spatial pattern and to reach the same level as the endogenous copies1,2. Only in exceptional cases has position-independent and copy number-dependent expression been reproduced3. The size constraint of standard constructs may prevent the inclusion of important remote regulatory elements. Yeast artificial chromosomes (YACs)4 provide a means of cloning large DNA fragments and the transfer of YAC DNA into somatic cells has been reported5-9. We have previously produced transgenic mice carrying a 35 kilobase YAC construct10.  Here we report the transfer of a 250 kilobase YAC covering the mouse tyrosinase gene into mice by pronuclear injection of gel-purified YAC DNA. The YAC was inserted into the mouse genome without major rearrangements and expression of the YAC-borne tyrosinase gene resulted in complete rescue of the albino phenotype of the recipient mice. Expression from the transgene reached levels comparable to that of the endogenous gene and showed copy number dependence and position independence.
C1 GERMAN CANC RES CTR,DIV MOLEC BIOL CELL 1,NEUENHEIMER FELD 280,W-6900 HEIDELBERG,GERMANY.
C3 Helmholtz Association; German Cancer Research Center (DKFZ)
NR 31
TC 233
Z9 278
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 258
EP 261
DI 10.1038/362258a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600060
PM 8459851
DA 2026-03-10
ER

PT J
AU MARTIKAINEN, PJ
   NYKANEN, H
   CRILL, P
   SILVOLA, J
AF MARTIKAINEN, PJ
   NYKANEN, H
   CRILL, P
   SILVOLA, J
TI EFFECT OF A LOWERED WATER-TABLE ON NITROUS-OXIDE FLUXES FROM NORTHERN PEATLANDS
SO NATURE
LA English
DT Article
ID carbon-dioxide; climate change; methane flux; fens
AB NORTHERN peatlands contain 20-30% of the total organic nitrogen and carbon in the world's soils1,2, and thus they apparently have the potential to exert a significant influence on the global atmospheric budget of the greenhouse gases carbon dioxide, methane and nitrous oxide (N2O). In the drier, warmer summer conditions predicted at high latitudes by some climate models3,4 as a result of greenhouse-gas forcing, northern peatlands would become drier, increasing the rate of mineralization of organic matter1,5 and of the microbial processes that produce N2O. These regions might therefore be expected to exert a strong feedback on climate. But whereas methane emissions have been well studied6,7, little is known about the effect on N2O fluxes of changes in the level of peatland water tables. Here we present a comparison of present-day N2O fluxes from virgin peatlands in Finland with those from sites in the same regions that were drained by ditching 30 and 50 years ago. The lowered water table had no effect on N2O emissions from nutrient-poor peat but enhanced those from nutrient-rich peat. We estimate that equivalent drying caused by climate change would increase the total emissions of N2O from northern peatlands by 0.03-0.1 teragrams of nitrogen per year, which is just 0.3-1% of the present global annual emissions. Thus northern peatlands are unlikely to exert a significant climate feedback from N2O emissions.
C1 UNIV JOENSUU, DEPT BIOL, SF-80101 JOENSUU, FINLAND.
   UNIV NEW HAMPSHIRE, EOS, COMPLEX SYST RES CTR, DURHAM, NH 03824 USA.
C3 University of Eastern Finland; University System Of New Hampshire; University of New Hampshire
RP MARTIKAINEN, PJ (corresponding author), NATL PUBL HLTH INST, DEPT ENVIRONM MICROBIOL, POB 95, SF-70701 KUOPIO, FINLAND.
NR 29
TC 300
Z9 340
U1 1
U2 134
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 51
EP 53
DI 10.1038/366051a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700050
DA 2026-03-10
ER

PT J
AU ANDREWS, NC
   ERDJUMENTBROMAGE, H
   DAVIDSON, MB
   TEMPST, P
   ORKIN, SH
AF ANDREWS, NC
   ERDJUMENTBROMAGE, H
   DAVIDSON, MB
   TEMPST, P
   ORKIN, SH
TI ERYTHROID TRANSCRIPTION FACTOR NF-E2 IS A HEMATOPOIETIC-SPECIFIC BASIC LEUCINE ZIPPER PROTEIN
SO NATURE
LA English
DT Article
ID beta-globin gene; dominant control region; dna-binding protein; porphobilinogen deaminase gene; locus-control region; amino-acid-sequence; transgenic mice; developmental regulation; functional-property; mammalian-cells
AB Expression of globin genes in developing erythroid cells is controlled by upstream locus control regions. Activity of these regions in vivo requires an erythroid-specific nuclear factor (NF-E2) that binds AP-1-like recognition sites. Its tissue-specific component (p45 NF-E2) has been characterized by complementary DNA cloning as a new basic region-leucine zipper protein which dimerizes with a ubiquitous partner to form native NF-E2.
C1 HARVARD UNIV, CHILDRENS HOSP,SCH MED,DANA FARBER CANC INST, DEPT PEDIAT,DIV HEMATOL ONCOL, BOSTON, MA 02115 USA.
   MEM SLOAN KETTERING CANC CTR, MOLEC BIOL PROGRAM, NEW YORK, NY 10021 USA.
   HOWARD HUGHES MED INST, BOSTON, MA 02115 USA.
C3 Harvard University; Harvard University Medical Affiliates; Dana-Farber Cancer Institute; Boston Children's Hospital; Harvard Medical School; Memorial Sloan Kettering Cancer Center; Howard Hughes Medical Institute
NR 56
TC 602
Z9 657
U1 0
U2 11
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 722
EP 728
DI 10.1038/362722a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000046
PM 8469283
DA 2026-03-10
ER

PT J
AU JIANG, Y
   ROSSI, G
   FERRONOVICK, S
AF JIANG, Y
   ROSSI, G
   FERRONOVICK, S
TI BET2P AND MAD2P ARE COMPONENTS OF A PRENYLTRANSFERASE THAT ADDS GERANYLGERANYL ONTO YPT1P AND SEC4P
SO NATURE
LA English
DT Article
ID gtp-binding protein; saccharomyces-cerevisiae; vesicular transport; gene-product; yeast; farnesyltransferase; transferase; cys; dependence; secretion
AB THREE different prenyltransferases have been identified in yeast and higher cells1-6, the farnesyltransferase and the type I and type II geranylgeranyltransferases (GGTase). The farnesyltransferase and GGTase-I modify peptides in vitro with the CAAX (C, Cys; A, aliphatic residue; X, terminal amino acid) consensus motif2,7. These enzymes are heterodimers that have different beta-subunits and a shared alpha-subunit8.  In yeast, the RAM2 gene encodes this alpha-subunit9. RAM2 is also homologous to MAD2, a yeast gene whose product has been implicated in the feedback control of mitosis10,11. We have shown that Bet2p is a component of the yeast GGTase-II (refs 6, 12) that geranylgeranylates Ypt1p, a small GTP-binding protein that mediates transport from the endoplasmic reticulum to the Golgi complex13-15.  Here we report that Mad2p is a component of this enzyme. Bet2p forms a complex with Mad2p that appears to bind geranylgeranyl pyrophosphate, but not farnesyl pyrophosphate. The efficient transfer of geranylgeranyl onto small GTP-binding proteins requires the presence of an additional activity.
C1 YALE UNIV,SCH MED,DEPT CELL BIOL,333 CEDAR ST,NEW HAVEN,CT 06510.
C3 Yale University
NR 27
TC 55
Z9 63
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 84
EP 86
DI 10.1038/366084a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700061
PM 8232542
DA 2026-03-10
ER

PT J
AU MELILLO, JM
   MCGUIRE, AD
   KICKLIGHTER, DW
   MOORE, B
   VOROSMARTY, CJ
   SCHLOSS, AL
AF MELILLO, JM
   MCGUIRE, AD
   KICKLIGHTER, DW
   MOORE, B
   VOROSMARTY, CJ
   SCHLOSS, AL
TI GLOBAL CLIMATE-CHANGE AND TERRESTRIAL NET PRIMARY PRODUCTION
SO NATURE
LA English
DT Article
ID co2 enrichment; elevated co2; nitrogen; growth; sensitivity; limitation; allocation; responses; nutrition; forests
AB A process-based model was used to estimate global patterns of net primary production and soil nitrogen cycling for contemporary climate conditions and current atmospheric CO2 concentration. Over half of the global annual net primary production was estimated to occur in the tropics, with most of the production attributable to tropical evergreen forest. The effects of CO2 doubling and associated climate changes were also explored. The responses in tropical and dry temperate ecosystems were dominated by CO2, but those in northern and moist temperate ecosystems reflected the effects of temperature on nitrogen availability.
C1 UNIV NEW HAMPSHIRE,INST STUDY EARTH OCEANS & SPACE,COMPLEX SYST RES CTR,DURHAM,NH 03824.
C3 University System Of New Hampshire; University of New Hampshire
RP MELILLO, JM (corresponding author), MARINE BIOL LAB,CTR ECOSYST,WOODS HOLE,MA 02543, USA.
NR 56
TC 1498
Z9 1883
U1 4
U2 705
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 234
EP 240
DI 10.1038/363234a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600042
DA 2026-03-10
ER

PT J
AU ARSUAGA, JL
   MARTINEZ, I
   GRACIA, A
   CARRETERO, JM
   CARBONELL, E
AF ARSUAGA, JL
   MARTINEZ, I
   GRACIA, A
   CARRETERO, JM
   CARBONELL, E
TI 3 NEW HUMAN SKULLS FROM THE SIMA-DE-LOS-HUESOS MIDDLE-PLEISTOCENE SITE IN SIERRA-DE-ATAPUERCA, SPAIN
SO NATURE
LA English
DT Article
ID dental remains; ibeas spain; evolution; region; sample; homo
AB THREE important fossil hominids were found in July 1992 in the Middle Pleistocene cave site called Sima de los Huesos (Sierra de Atapuerca, Burgos, Northern Spain). One is a complete calvaria (cranium 4), the second a virtually complete cranium (cranium 5), the third represents a more fragmentary cranium of an immature individual (cranium 6). There is a large difference in size between the two adult specimens (for example endocranial volume 1,125 cm3 versus 1,390 cm3). The Atapuerca human remains are dated to >300,000 years. The Atapuerca cranial sample fits within the 'archaic Homo sapiens' group, but is well differentiated from the Asian Homo erectus group. The extensive Atapuerca human collection is the most complete sample of Middle Pleistocene humans yet discovered from one site, and appears to document an early stage in Neanderthal evolution.
C1 UNIV ROVIRA & VIRGILI,ARQUEOL LAB,TARRAGONA,SPAIN.
C3 Universitat Rovira i Virgili
RP ARSUAGA, JL (corresponding author), UNIV COMPLUTENSE MADRID,DEPT PALEONTOL,E-28040 MADRID,SPAIN.
NR 26
TC 207
Z9 224
U1 0
U2 30
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 534
EP 537
DI 10.1038/362534a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300051
PM 8464493
DA 2026-03-10
ER

PT J
AU BIEGLER, R
   MORRIS, RGM
AF BIEGLER, R
   MORRIS, RGM
TI LANDMARK STABILITY IS A PREREQUISITE FOR SPATIAL BUT NOT DISCRIMINATION-LEARNING
SO NATURE
LA English
DT Article
ID memory; hippocampus; rats
AB NEURONS sensitive to both place and direction from distinct regions of the hippocampal formation1,2, allometric relationships between spatial learning and hippocampal structure3,4 and pronounced impairments in spatial learning after lesions in this area5-8, indicate that the hippocampal formation subserves allocentric spatial learning9,10. To learn more about the process of spatial representation, we have developed a task that provides independent control of both landmark and directional cues. On the basis of physiological11 and behavioural12 work, this task also makes it possible to investigate the relevance of associative learning principles, such as predictability13, to the spatial domain. We report here that although rats learn to discriminate between landmarks on the basis of their proximity to a reliably predicted food reward, they will only learn to use them to represent its location if they maintain stable locations within a geometric frame of reference.
C1 UNIV EDINBURGH,SCH MED,DEPT PHARMACOL,NEUROSCI LAB,1 GEORGE SQ,EDINBURGH EH8 9JZ,MIDLOTHIAN,SCOTLAND.
C3 University of Edinburgh
FU Wellcome Trust Funding Source: Medline
NR 22
TC 127
Z9 146
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 631
EP 633
DI 10.1038/361631a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600062
PM 8437622
DA 2026-03-10
ER

PT J
AU GRUN, E
   ZOOK, HA
   BAGUHL, M
   BALOGH, A
   BAME, SJ
   FECHTIG, H
   FORSYTH, R
   HANNER, MS
   HORANYI, M
   KISSEL, J
   LINDBLAD, BA
   LINKERT, D
   LINKERT, G
   MANN, I
   MCDONNELL, JAM
   MORFILL, GE
   PHILLIPS, JL
   POLANSKEY, C
   SCHWEHM, G
   SIDDIQUE, N
   STAUBACH, P
   SVESTKA, J
   TAYLOR, A
AF GRUN, E
   ZOOK, HA
   BAGUHL, M
   BALOGH, A
   BAME, SJ
   FECHTIG, H
   FORSYTH, R
   HANNER, MS
   HORANYI, M
   KISSEL, J
   LINDBLAD, BA
   LINKERT, D
   LINKERT, G
   MANN, I
   MCDONNELL, JAM
   MORFILL, GE
   PHILLIPS, JL
   POLANSKEY, C
   SCHWEHM, G
   SIDDIQUE, N
   STAUBACH, P
   SVESTKA, J
   TAYLOR, A
TI DISCOVERY OF JOVIAN DUST STREAMS AND INTERSTELLAR GRAINS BY THE ULYSSES SPACECRAFT
SO NATURE
LA English
DT Article
ID inter-stellar grains; ring; origin
AB ON 8 February 1992, the Ulysses spacecraft flew by Jupiter at a distance of 5.4 AU from the Sun. During the encounter, the spacecraft was deflected into a new orbit, inclined at about 80-degrees to the ecliptic plane, which will ultimately lead Ulysses over the polar regions of the Sun1. Within 1 AU from Jupiter, the onboard dust detector2 recorded periodic bursts of submicrometre dust particles, with durations ranging from several hours to two days, and occurring at approximately monthly intervals (28 +/- 3 days). These particles arrived at Ulysses in collimated streams radiating from close to the line-of-sight direction to Jupiter, suggesting a jovian origin for the periodic bursts. Ulysses also detected a flux of micrometre-sized dust particles moving in high-velocity (greater-than-or-equal-to 26 km s-1) retrograde orbits (opposite to the motion of the planets); we identify these grains as being of interstellar origin.
C1 NASA, LYNDON B JOHNSON SPACE CTR, HOUSTON, TX 77058 USA.
   UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, BLACKETT LAB, LONDON SW7 2BZ, ENGLAND.
   LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA.
   JET PROP LAB, PASADENA, CA 91109 USA.
   UNIV COLORADO, ATMOSPHER & SPACE PHYS LAB, BOULDER, CO 80309 USA.
   LUND OBSERV, S-221 LUND, SWEDEN.
   MAX PLANCK INST AERON, W-3411 KATLENBURG DUHM, GERMANY.
   UNIV KENT, CANTERBURY CT2 7NR, ENGLAND.
   MAX PLANCK INST EXTRATERR PHYS, W-8046 GARCHING, GERMANY.
   EUROPEAN SPACE TECHNOL CTR, 2200 AG NOORDWIJK, NETHERLANDS.
   PRAGUE OBSERV, CS-11846 PRAGUE 1, CZECHOSLOVAKIA.
C3 National Aeronautics & Space Administration (NASA); NASA Johnson Space Center; Imperial College London; United States Department of Energy (DOE); Los Alamos National Laboratory; National Aeronautics & Space Administration (NASA); NASA Jet Propulsion Laboratory (JPL); University of Colorado System; University of Colorado Boulder; Max Planck Society; University of Kent; Max Planck Society; European Space Agency; European Space Research & Technology Centre
RP GRUN, E (corresponding author), MAX PLANCK INST NUCL PHYS, W-6900 HEIDELBERG 1, GERMANY.
NR 23
TC 333
Z9 348
U1 0
U2 10
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 428
EP 430
DI 10.1038/362428a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400075
DA 2026-03-10
ER

PT J
AU MALMQVIST, M
AF MALMQVIST, M
TI BIOSPECIFIC INTERACTION ANALYSIS USING BIOSENSOR TECHNOLOGY
SO NATURE
LA English
DT Article
ID surface-plasmon resonance; proteins
RP MALMQVIST, M (corresponding author), PHARMACIA BIOSENSOR AB,S-75182 UPPSALA,SWEDEN.
NR 24
TC 538
Z9 689
U1 0
U2 124
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 186
EP 187
DI 10.1038/361186a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600070
PM 7678451
DA 2026-03-10
ER

PT J
AU DEMATTEIS, MA
   SANTINI, G
   KAHN, RA
   DITULLIO, G
   LUINI, A
AF DEMATTEIS, MA
   SANTINI, G
   KAHN, RA
   DITULLIO, G
   LUINI, A
TI RECEPTOR AND PROTEIN KINASE-C-MEDIATED REGULATION OF ARF BINDING TO THE GOLGI-COMPLEX
SO NATURE
LA English
DT Article
ID adp-ribosylation factor; brefeldin-a; guanine-nucleotide; coated vesicles; cell-surface; beta-cop; secretion; inhibition; transport; membranes
AB THE formation of constitutive transport vesicles involves the association of non-clathrin coat proteins to transport organelles1,2 . Here we report that IgE receptors and protein kinase C (PKC) regulate the GTP-dependent binding of the two coat proteins ADP-ribosylation factor (ARF) and beta-COP3-5 to Golgi membranes in rat basophilic leukaemia cells. Activation of IgE receptors and PKC prevented the ARF and beta-COP dissociation from Golgi membranes that occurs in permeabilized cells in the absence of GTP and potentiated the association-promoting effects of GTP and the G protein activator fluoroaluminate. In contrast, PKC downregulation and PKC inhibition abolished the activity of GTP and fluoro-luminate in promoting ARF binding to the Golgi complex. Studies of ARF binding to isolated Golgi membranes gave similiar results. These findings suggest that coat assembly on Golgi membranes, and thus possibly constitutive secretory traffic, is modulated by membrane receptors and second messengers.
C1 IST RIC FARMACOL MARIO NEGRI,CONSORZIO MARIO NEGRI SUD,MOLEC NEUROBIOL LAB,I-66030 SANTA MARIA IMBAR,ITALY.
   NCI,DIV CANC TREATMENT,BIOL CHEM LAB,BETHESDA,MD 20892.
C3 Istituto di Ricerche Farmacologiche Mario Negri IRCCS; Consorzio Mario Negri Sud; National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI)
RP DEMATTEIS, MA (corresponding author), IST RIC FARMACOL MARIO NEGRI,CONSORZIO MARIO NEGRI SUD,PHYSIOPATHOL SECRET UNIT,I-66030 SANTA MARIA IMBAR,ITALY.
NR 36
TC 140
Z9 149
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 818
EP 821
DI 10.1038/364818a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100060
PM 7689177
DA 2026-03-10
ER

PT J
AU BATSON, PE
AF BATSON, PE
TI SIMULTANEOUS STEM IMAGING AND ELECTRON-ENERGY-LOSS SPECTROSCOPY WITH ATOMIC-COLUMN SENSITIVITY
SO NATURE
LA English
DT Article
AB IMAGING with the scanning transmission electron microscope (STEM) has recently gained in resolution from the use of the annular dark-field (ADF) method1,2, which produces a signal that is highly sensitive to atomic number. There is a possibility that electrons from the probe beam that are scattered inelastically might be collected to provide a spectroscopic signal containing information about atomic bonding and electronic structure-this is the basis of the standard electron energy-loss spectroscopy (EELS) technique. Browning et al.3,4 have shown recently that an EELS signal from absorption of atomic core levels can be used, in conjunction with ADF imaging, to obtain information about chemical composition at atomic resolution. Here I report the use of a similar approach to resolve the different bonding states of silicon atoms (Si0, Si2+, Si4+) across a Si-SiO2 interface. The oxidation state of individual columns of unit cells, containing pairs of silicon atoms, can be resolved with this method, allowing the structure of the interface to be characterized in great detail.
RP BATSON, PE (corresponding author), IBM CORP,THOMAS J WATSON RES CTR,YORKTOWN HTS,NY 10598, USA.
NR 10
TC 314
Z9 342
U1 1
U2 118
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 23
PY 1993
VL 366
IS 6457
BP 727
EP 728
DI 10.1038/366727a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MN264
UT WOS:A1993MN26400022
DA 2026-03-10
ER

PT J
AU TAO, WC
   OCONNELL, RJ
AF TAO, WC
   OCONNELL, RJ
TI DEFORMATION OF A WEAK SUBDUCTED SLAB AND VARIATION OF SEISMICITY WITH DEPTH
SO NATURE
LA English
DT Article
ID deep-focus earthquakes; mantle beneath; tonga; intermediate; convection; plates; zone; flow
AB OCEANIC lithosphere is assumed to possess platelike properties whether it is lying at the Earth's surface or descending deep into the mantle; yet the geometries of subducting slabs indicate significant deformation as they descend through the mantle1-4, suggesting that lithospheric plates might be so weakened during subduction as to act not as a rigid solid, but as a viscous fluid. Numerical and laboratory experiments have shown that fluid 'slabs' can indeed take on realistic profiles5-7 ;however, it has not been clear whether a fluid or 'weak' model of slab dynamics can account for deep earthquakes, which are usually ascribed to the deformation of a rigid or 'strong' slab. Here we show, using numerical simulations of slab evolution, that a weak slab model is in fact consistent with seismic observations. Assuming that earthquakes occur at a rate proportional to deformation rate, we reproduce the observed variation with depth of seismicity rate and focal mechanisms, and the cessation of seismicity at 670 km depth. Provided that sinking material encounters resistance at depth (here modelled as a viscosity jump at 670 km), the pattern of seismicity can be explained by any mechanism for deep earthquakes in which the rate of seismicity is proportional to strain rate in the slab.
RP TAO, WC (corresponding author), HARVARD UNIV,DEPT EARTH & PLANETARY SCI,20 OXFORD ST,CAMBRIDGE,MA 02138, USA.
NR 20
TC 39
Z9 44
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 626
EP 628
DI 10.1038/361626a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600060
DA 2026-03-10
ER

PT J
AU BLEWITT, G
   HEFLIN, MB
   HURST, KJ
   JEFFERSON, DC
   WEBB, FH
   ZUMBERGE, JF
AF BLEWITT, G
   HEFLIN, MB
   HURST, KJ
   JEFFERSON, DC
   WEBB, FH
   ZUMBERGE, JF
TI ABSOLUTE FAR-FIELD DISPLACEMENTS FROM THE 28 JUNE 1992 LANDERS EARTHQUAKE SEQUENCE
SO NATURE
LA English
DT Article
ID global positioning system; california; precision; orbit
AB ON 28 June 1992, the largest earthquake in California in 40 years (surface-wave magnitude M(s) = 7.5) occurred near the small town of Landers, in southeastern California, and was followed three hours later by the nearby M(s) 6.5 Big Bear earthquake1. Fortuitously, the Landers earthquake sequence coincided with the first week of the official three-month test period of the International Global Positioning System and Geodynamics Service2 (IGS), giving us an unprecendented opportunity to detect absolute pre-, co- and post-seismic displacements at a distance of 50-200 km from the main rupture with millimetre-level precision. Mutual and independent confirmation of some of our geodetic results are demonstrated by Bock et al. in this issue3. For the Landers earthquake, the observed displacements indicate that the depth of the bottom of the rupture is shallower towards the northern end, displacements were dominantly symmetric, and the rupture extended further south on the Johnson Valley fault than has been mapped on the basis of surface ground offsets. The combined geodetic moment for the Landers and Big Bear earthquakes (1.1 x 10(20) N m-1) agrees well with teleseismic estimates.
RP BLEWITT, G (corresponding author), JET PROP LAB,PASADENA,CA 91109, USA.
NR 17
TC 58
Z9 64
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 340
EP 342
DI 10.1038/361340a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000052
DA 2026-03-10
ER

PT J
AU TSANG, SC
   HARRIS, PJF
   GREEN, MLH
AF TSANG, SC
   HARRIS, PJF
   GREEN, MLH
TI THINNING AND OPENING OF CARBON NANOTUBES BY OXIDATION USING CARBON-DIOXIDE
SO NATURE
LA English
DT Article
AB THE discovery1 and bulk synthesis2 of carbon nanotubes has stimulated great interest. It has been suggested that these structures may have useful electronic3-5 and mechanical6 properties, and these might be modified by introducing foreign materials into the nanotubes. But the tubes are invariably capped at the ends. Ajayan and Iijima7 have succeeded in drawing molten material (lead or one of its compounds) into the tubes by heating them in the presence of lead and oxygen; less than 1% of the tubes in the sample studied could be filled in this way. Here we report that heating in carbon dioxide gas can result in the partial or complete destruction of the tube caps and stripping of the outer layers to produce thinner tubes. In some cases, we have thinned the extremity of tubes to a single layer. The opened tubes can be regarded as nanoscale test-tubes for adsorption of other molecules, and this controlled method of thinning may allow studies of the properties of single tubes.
C1 UNIV OXFORD,INORGAN CHEM LAB,S PARKS RD,OXFORD OX1 3QR,ENGLAND.
   UNIV OXFORD,CHEM CRYSTALLOG LAB,OXFORD OX1 3PD,ENGLAND.
C3 University of Oxford; University of Oxford
NR 15
TC 543
Z9 607
U1 0
U2 148
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 520
EP 522
DI 10.1038/362520a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300046
DA 2026-03-10
ER

PT J
AU KLEIN, D
   ONO, H
   OHUIGIN, C
   VINCEK, V
   GOLDSCHMIDT, T
   KLEIN, J
AF KLEIN, D
   ONO, H
   OHUIGIN, C
   VINCEK, V
   GOLDSCHMIDT, T
   KLEIN, J
TI EXTENSIVE MHC VARIABILITY IN CICHLID FISHES OF LAKE MALAWI
SO NATURE
LA English
DT Article
ID major histocompatibility complex; evolution; genes
AB LAKE Malawi in East Africa harbours 500-1,000 endemic species of cichlid fishes, all presumably derived by adaptive radiation from a single founding population within the past two million years1-3. The species of this 'flock' differ strikingly in their ecology and behaviour4, moderately in their external morphology1 and very little in their molecular characteristics5,6. Here we describe high sequence variability of class II major histocompatibility complex genes in a sample of species from Lake Malawi. The variability provides a set of molecular markers for studying adaptive radiation and should be useful for estimating the size of the population that founded the species flock.
C1 MAX PLANCK INST BIOL,IMMUNGENET ABT,W-7400 TUBINGEN,GERMANY.
   LEIDEN UNIV,ZOOL LAB,ECOL MORPHOL RES GRP,2300 RA LEIDEN,NETHERLANDS.
   YOKOHAMA CITY UNIV,SCH MED,DEPT DERMATOL,KANAZAWA KU,YOKOHAMA 236,JAPAN.
C3 Max Planck Society; Leiden University - Excl LUMC; Leiden University; Yokohama City University
RP KLEIN, D (corresponding author), UNIV MIAMI,DEPT MICROBIOL & IMMUNOL,MIAMI,FL 33101, USA.
NR 14
TC 126
Z9 135
U1 0
U2 14
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 330
EP 334
DI 10.1038/364330a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000055
PM 8332189
DA 2026-03-10
ER

PT J
AU EALES, S
   RAWLINGS, S
   PUXLEY, P
   ROCCAVOLMERANGE, B
   KUNTZ, K
AF EALES, S
   RAWLINGS, S
   PUXLEY, P
   ROCCAVOLMERANGE, B
   KUNTZ, K
TI EVIDENCE THAT THE Z = 3.4 RADIO GALAXY B2-0902+34 MAY BE A PROTOGALAXY
SO NATURE
LA English
DT Article
ID high-redshift; stellar population; emission
AB THE monochromatic luminosities of high-redshift (z > 3) radio galaxies rise steeply between wavelengths of about 2,000 and 5,000 angstrom, to form a characteristic 'red bump'1-6. It is usually assumed that this bump arises from the photospheric emission of red, post-main-sequence stars. For a sufficient number of stars of this type to have evolved, however, these galaxies must be at least 0.4-2 Gyr old; yet z = 3 corresponds to only 1.7 Gyr after the Big Bang (assuming a Hubble constant of 50 km s-1 Mpc-1 and that OMEGA0 = 1), bringing the larger age estimates uncomfortably close to the beginning of the Universe. Here we show that, at least in the case of the high-redshift radio galaxy B2 0902 + 34, the basic assumption is incorrect: the red bump is caused not by photospheric emission from post-main-sequence stars, but by the presence of bright emission lines from doubly ionized oxygen. Both the spectrum and the luminosity of the underlying continuum suggest that B2 0902 + 34 is a galaxy observed during its initial burst of star formation.
C1 ROYAL OBSERV, EDINBURGH EH9 3HJ, MIDLOTHIAN, SCOTLAND.
   INST ASTROPHYS, F-75014 PARIS, FRANCE.
   UNIV OXFORD, DEPT ASTROPHYS, NUCL & ASTROPHYS LAB, OXFORD OX1 3RH, ENGLAND.
   SPACE TELESCOPE SCI INST, BALTIMORE, MD 21218 USA.
C3 University of Edinburgh; Sorbonne Universite; University of Oxford; Space Telescope Science Institute
RP EALES, S (corresponding author), UNIV TORONTO, DEPT ASTRON, 60 ST GEORGE ST, TORONTO M5S 1A1, ONTARIO, CANADA.
NR 27
TC 40
Z9 41
U1 0
U2 0
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 140
EP 142
DI 10.1038/363140a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100039
DA 2026-03-10
ER

PT J
AU BLUM, ML
   DOWN, JA
   GURNETT, AM
   CARRINGTON, M
   TURNER, MJ
   WILEY, DC
AF BLUM, ML
   DOWN, JA
   GURNETT, AM
   CARRINGTON, M
   TURNER, MJ
   WILEY, DC
TI A STRUCTURAL MOTIF IN THE VARIANT SURFACE GLYCOPROTEINS OF TRYPANOSOMA-BRUCEI
SO NATURE
LA English
DT Article
ID amino-acid sequences; antigenic variation; point mutations; proteins; domains; genes; virus; purification; recognition; rhodesiense
AB The variable domain of the trypanosome variant surface glycoprotein (VSG) ILTat 1.24 has been shown by X-ray crystallography to resemble closely the structures of VSG MITat 1.2, despite their low sequence similarity. Specific structural features of these VSGs, including substitution of carbohydrate for an alpha-helix, can be found in other VSG sequences. Thus antigenic variation in trypanosomes is accomplished by sequence variation, not gross structural alteration; the extensive sequence differences among VSGs may be required for another reason, such as the avoidance of recognition by helper T cells. Additionally, VSG sequences are found to define families, within a VSG superfamily, which have evolved in the trypanosome genome.
C1 HARVARD UNIV,HOWARD HUGHES MED INST,CAMBRIDGE,MA 02138.
   HARVARD UNIV,DEPT BIOCHEM & MOLEC BIOL,CAMBRIDGE,MA 02138.
   MERCK SHARP & DOHME LTD,RAHWAY,NJ 07065.
   UNIV CAMBRIDGE,DEPT BIOCHEM,CAMBRIDGE CB2 1QW,ENGLAND.
C3 Harvard University; Howard Hughes Medical Institute; Harvard University; Merck & Company; University of Cambridge
NR 53
TC 186
Z9 207
U1 0
U2 13
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 603
EP 609
DI 10.1038/362603a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800037
PM 8464512
DA 2026-03-10
ER

PT J
AU LI, E
   BEARD, C
   JAENISCH, R
AF LI, E
   BEARD, C
   JAENISCH, R
TI ROLE FOR DNA METHYLATION IN GENOMIC IMPRINTING
SO NATURE
LA English
DT Article
ID determines methylation; transgenic mice; gene; gametogenesis; embryogenesis; expression; rna
AB THE paternal and maternal genomes are not equivalent and both are required for mammalian development1,2. The difference between the parental genomes is believed to be due to gamete-specific differential modification, a process known as genomic imprinting. The study of transgene methylation has shown that methylation patterns can be inherited in a parent-of-origin-specific manner3-7, suggesting that DNA methylation may play a role in genomic imprinting. The functional significance of DNA methylation in genomic imprinting was strengthened by the recent finding that CpG islands (or sites) in three imprinted genes, H19, insulin-like growth factor 2 (Igf-2), and Igf-2 receptor (Igf-2r), are differentially methylated depending on their parental origin8-12. We have examined the expression of these three imprinted genes in mutant mice that are deficient in DNA methyltransferase activity13. We report here that expression of all three genes was affected in mutant embryos: the normally silent paternal allele of the H19 gene was activated, whereas the normally active paternal allele of die Igf-2 gene and the active maternal allele of the Igf-2r gene were repressed. Our results demonstrate that a normal level of DNA methylation is required for controlling differential expression of the paternal and maternal alleles of imprinted genes.
C1 MIT,WHITEHEAD INST BIOMED RES,9 CAMBRIDGE CTR,CAMBRIDGE,MA 02142.
   MIT,DEPT BIOL,CAMBRIDGE,MA 02142.
C3 Massachusetts Institute of Technology (MIT); Whitehead Institute; Massachusetts Institute of Technology (MIT)
NR 21
TC 1832
Z9 2154
U1 2
U2 195
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 362
EP 365
DI 10.1038/366362a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500054
PM 8247133
DA 2026-03-10
ER

PT J
AU BAILEY, B
   FARKAS, DL
   TAYLOR, DL
   LANNI, F
AF BAILEY, B
   FARKAS, DL
   TAYLOR, DL
   LANNI, F
TI ENHANCEMENT OF AXIAL RESOLUTION IN FLUORESCENCE MICROSCOPY BY STANDING-WAVE EXCITATION
SO NATURE
LA English
DT Article
ID leading-edge; 3 dimensions; fibroblasts; actin; cells; organization; transport
AB THE use of fluorescence microscopy for investigating the three-dimensional structure of cells and tissue is of growing importance in cell biology, biophysics and biomedicine. Three-dimensional data are obtained by recording a series of images of the specimen as it is stepped through the focal plane of the microscope1-3. Whether by direct imaging or by confocal scanning4,5, diffraction effects and noise generally limit axial resolution to about 0.5 mum. Here we describe a fluorescence microscope in which axial resolution is increased to better than 0.05 mum by using the principle of standing-wave excitation of fluorescence. Standing waves formed by interference in laser illumination create an excitation field with closely spaced nodes and antinodes, allowing optical sectioning of the specimen at very high resolution. We use this technique to obtain images of actin fibres and filaments in fixed cells, actin single filaments in vitro and myosin II in a living cell.
C1 CARNEGIE MELLON UNIV, CTR LIGHT MICROSCOPE IMAGING & BIOTECHNOL, 4400 5TH AVE, PITTSBURGH, PA 15213 USA.
   CARNEGIE MELLON UNIV, DEPT BIOL SCI, PITTSBURGH, PA 15213 USA.
   CARNEGIE MELLON UNIV, DEPT PHYS, PITTSBURGH, PA 15213 USA.
C3 Carnegie Mellon University; Carnegie Mellon University; Carnegie Mellon University
NR 27
TC 249
Z9 339
U1 2
U2 98
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 44
EP 48
DI 10.1038/366044a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700048
PM 8232536
DA 2026-03-10
ER

PT J
AU QIAN, Z
   GILBERT, ME
   COLICOS, MA
   KANDEL, ER
   KUHL, D
AF QIAN, Z
   GILBERT, ME
   COLICOS, MA
   KANDEL, ER
   KUHL, D
TI TISSUE-PLASMINOGEN ACTIVATOR IS INDUCED AS AN IMMEDIATE EARLY GENE DURING SEIZURE, KINDLING AND LONG-TERM POTENTIATION
SO NATURE
LA English
DT Article
ID nerve growth-factor; neurite outgrowth; messenger-rna; expression; hippocampus; receptor; protein; memory; cells; rat
AB THE requirement of protein and messenger RNA synthesis for long-term memory1,2 suggests that neural activity induced by learning initiates a cascade of gene expression3. Here we use differential screening to identify five immediate-early genes induced by neuronal activity. One of these is tissue-plasminogen activator (tPA), an extracellular serine protease, which is induced with different spatial patterns in the brain by three activity-dependent events: (1) convulsive seizure increases expression of tPA in the whole brain; (2) stimulation of the perforant path produces an epileptiform after-discharge that ultimately leads to kindling increases the levels of tPA throughout the hippocampus bilaterally; and (3) brief high-frequency stimulation of the perforant path that produces long-term potentiation (LTP) causes an NMDA (N-methyl-D-aspartate) receptor-mediated increase in the levels of tPA mRNA which is restricted to the granule cells of the ipsilateral dentate gyrus. As release of tPA is correlated with morphological differentiation4-6, the increased expression of tPA may play a role in the structural changes that accompany activity-dependent plasticity7-10.
C1 COLUMBIA UNIV COLL PHYS & SURG,HOWARD HUGHES MED INST,NEW YORK,NY 10032.
   MANTECH ENVIRONM TECHNOL INC,RES TRIANGLE PK,NC 27709.
C3 Howard Hughes Medical Institute; Columbia University
RP QIAN, Z (corresponding author), COLUMBIA UNIV COLL PHYS & SURG,CTR NEUROBIOL & BEHAV,722 W 168TH ST,NEW YORK,NY 10032, USA.
NR 29
TC 665
Z9 711
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 453
EP 457
DI 10.1038/361453a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300062
PM 8429885
DA 2026-03-10
ER

PT J
AU ALLEN, DA
   BURTON, MG
AF ALLEN, DA
   BURTON, MG
TI EXPLOSIVE EJECTION OF MATTER ASSOCIATED WITH STAR FORMATION IN THE ORION NEBULA
SO NATURE
LA English
DT Article
ID herbig-haro objects; molecular-hydrogen emission; m42; clouds; line
AB TIGHTLY collimated outflows of gas are often associated with regions of star formation; they interact with the ambient interstellar medium to produce the knots of shock-excited emission known as Herbig-Haro (HH) objects1,2. Two interpretations have been suggested for these objects: they may represent either the shocking of dense clumps of material that have been ejected into the surrounding molecular cloud3, or the interaction of stationary knots with fast, low-density jets4,5. Here we report the discovery of a complex of HH objects and associated wakes that require compact knots of material to have been ejected over a wide opening angle in a seemingly explosive event. Our observations suggest that, at least in this case, the former interpretation is correct, and they highlight the need to search other stay-forming regions in order to establish the frequency of such events.
RP ALLEN, DA (corresponding author), ANGLO AUSTRALIAN OBSERV,POB 296,EPPING,NSW 2121,AUSTRALIA.
NR 34
TC 236
Z9 240
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 54
EP 56
DI 10.1038/363054a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200053
DA 2026-03-10
ER

PT J
AU GOTT, JR
AF GOTT, JR
TI IMPLICATIONS OF THE COPERNICAN PRINCIPLE FOR OUR FUTURE-PROSPECTS
SO NATURE
LA English
DT Article
ID evolution; universe; world; end
AB Making only the assumption that you are a random intelligent observer, limits for the total longevity of our species of 0.2 million to 8 million years can be derived at the 95% confidence level. Further consideration indicates that we are unlikely to colonize the Galaxy, and that we are likely to have a higher population than the median for intelligent species.
RP GOTT, JR (corresponding author), PRINCETON UNIV,DEPT ASTROPHYS SCI,PRINCETON,NJ 08544, USA.
NR 48
TC 186
Z9 194
U1 0
U2 30
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 315
EP 319
DI 10.1038/363315a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700042
DA 2026-03-10
ER

PT J
AU MULLIGAN, MS
   PAULSON, JC
   DEFREES, S
   ZHENG, ZL
   LOWE, JB
   WARD, PA
AF MULLIGAN, MS
   PAULSON, JC
   DEFREES, S
   ZHENG, ZL
   LOWE, JB
   WARD, PA
TI PROTECTIVE EFFECTS OF OLIGOSACCHARIDES IN P-SELECTIN-DEPENDENT LUNG INJURY
SO NATURE
LA English
DT Article
ID adhesion; neutrophils; gmp-140; activation
AB NEUTROPHIL recruitment into tissues is a multistep process involving sequential engagement of adhesion molecules, including selectins (E,P,L), which are reactive with oligosaccharides, and the family of beta2 integrins which are reactive with endothelial intercellular adhesion molecules1-3. These processes result in the initial rolling of leukocytes along the endothelial surfaces, followed by the firm attachment of leukocytes to the endothelium. The intravenous infusion of cobra venom factor into rats results in acute lung injury that is neutrophil-dependent, oxygen radical mediated and P-selectin-dependent4,5. Here we report that infusion of sialyl-Lewis X, a ligand for P-selectin6-9, dramatically reduced lung injury and diminished the tissue accumulation of neutrophils, whereas irrelevant oligosaccharides had no such effects. These results suggest that sialyl-Lewis X carbohydrates maybe used as a new strategy for anti-inflammatory therapy.
C1 UNIV MICHIGAN,SCH MED,DEPT PATHOL,1301 CATHERINE RD,ANN ARBOR,MI 48109.
   CYTEL CORP,SAN DIEGO,CA 92121.
   UNIV MICHIGAN,SCH MED,HOWARD HUGHES MED INST,ANN ARBOR,MI 48109.
C3 University of Michigan System; University of Michigan; Cytel; University of Michigan System; University of Michigan; Howard Hughes Medical Institute
NR 14
TC 323
Z9 367
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 149
EP 151
DI 10.1038/364149a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700050
PM 7686631
DA 2026-03-10
ER

PT J
AU MADDOX, J
AF MADDOX, J
TI INDIA GREAT AMBITION TO SUCCEED
SO NATURE
LA English
DT Article
NR 2
TC 5
Z9 5
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 611
EP 614
DI 
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500023
DA 2026-03-10
ER

PT J
AU FUSHIMI, K
   UCHIDA, S
   HARA, Y
   HIRATA, Y
   MARUMO, F
   SASAKI, S
AF FUSHIMI, K
   UCHIDA, S
   HARA, Y
   HIRATA, Y
   MARUMO, F
   SASAKI, S
TI CLONING AND EXPRESSION OF APICAL MEMBRANE WATER CHANNEL OF RAT-KIDNEY COLLECTING TUBULE
SO NATURE
LA English
DT Article
ID major intrinsic protein; xenopus oocytes; sequence; polymerase; nucleotide; family; lens; mip
AB CONCENTRATING urine is mandatory for most mammals to prevent water loss from the body. Concentrated urine is produced in response to vasopressin by the transepithelial recovery of water from the lumen of the kidney collecting tubule through highly water-permeable membranes1,2. In this nephron segment, vasopressin regulates water permeability by endo- and exocytosis of water channels from or to the apical membrane3,4. CHIP28 is a water channel in red blood cells and the kidney proximal tubule5, but it is not expressed in the collecting tubule6. Here we report the cloning of the complementary DNA for WCH-CD, a water channel of the apical membrane of the kidney collecting tubule. WCH-CD is 42% identical in amino-acid sequence to CHIP28. WCH-CD transcripts are detected only in the collecting tubule of the kidney. Immunohistochemically, WCH-CD is localized to the apical region of the kidney collecting tubule cells. Expression of WCH-CD in Xenopus oocytes markedly increases osmotic water permeability. The functional expression and the limited localization of WCH-CD to the apical region of the kidney collecting tubule suggest that WCH-CD is the vasopressin-regulated water channel.
C1 TOKYO MED & DENT UNIV,DEPT BIOCHEM,TOKYO 113,JAPAN.
C3 Institute of Science Tokyo; Tokyo Medical & Dental University (TMDU)
RP FUSHIMI, K (corresponding author), TOKYO MED & DENT UNIV,DEPT INTERNAL MED 2,1-5-45 YUSHIMA,BUNKYO KU,TOKYO 113,JAPAN.
NR 24
TC 926
Z9 965
U1 0
U2 33
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 549
EP 552
DI 10.1038/361549a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400065
PM 8429910
DA 2026-03-10
ER

PT J
AU MILBURN, MV
   HASSELL, AM
   LAMBERT, MH
   JORDAN, SR
   PROUDFOOT, AEI
   GRABER, P
   WELLS, TNC
AF MILBURN, MV
   HASSELL, AM
   LAMBERT, MH
   JORDAN, SR
   PROUDFOOT, AEI
   GRABER, P
   WELLS, TNC
TI A NOVEL DIMER CONFIGURATION REVEALED BY THE CRYSTAL-STRUCTURE AT 2.4 ANGSTROM RESOLUTION OF HUMAN INTERLEUKIN-5
SO NATURE
LA English
DT Article
ID amino-acid sequence; 3-dimensional structure; receptor
AB INTERLEUKIN-5 (IL-5) is a lineage-specific cytokine for eosinophilpoiesis and plays an important part in diseases associated with increased eosinophils, such as asthma1,2. Human IL-5 is a disulphide-linked homodimer with 115 amino-acid residues in each chain 2. The crystal structure at 2.4 angstrom resolution reveals a novel two-domain structure, with each domain showing a striking similarity to the cytokine fold found in granulocyte macrophage3 and macrophage4 colony-stimulating factors, IL-2 (ref. 5), IL-4 (ref. 6), and human7 and porcine8 growth hormones. IL-5 is unique in that each domain requires the participation of two chains. The IL-5 structure consists of two left-handed bundles of four helices laid end to end and two short beta-sheets on opposite sides of the molecule. Surprisingly, the C-terminal strand and helix of one chain complete a bundle of four helices and a beta-sheet with the N-terminal three helices and one strand of the other chain. The structure of IL-5 provides a molecular basis for the design of antagonists and agonists that would delineate receptor recognition determinants critical in signal transduction. This structure determination extends the family of the cytokine bundle of four helices and emphasizes its fundamental significance and versatility in recognizing its receptor.
C1 GLAXO RES INST,DEPT STRUCT & BIOPHYS CHEM,RES TRIANGLE PK,NC 27709.
   GLAXO INST MOLEC BIOL,CH-1228 PLAN LES OUATES,SWITZERLAND.
C3 GlaxoSmithKline; Glaxosmithkline USA; GlaxoSmithKline; GlaxoSmithKline Switzerland
RP MILBURN, MV (corresponding author), CHILDRENS HOSP MED CTR,MOLEC MED LAB,ENDERS 673,300 LONGWOOD AVE,BOSTON,MA 02115, USA.
NR 35
TC 241
Z9 269
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 172
EP 176
DI 10.1038/363172a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100051
PM 8483502
DA 2026-03-10
ER

PT J
AU ITO, E
   TOKI, T
   ISHIHARA, H
   OHTANI, H
   GU, L
   YOKOYAMA, M
   ENGEL, JD
   YAMAMOTO, M
AF ITO, E
   TOKI, T
   ISHIHARA, H
   OHTANI, H
   GU, L
   YOKOYAMA, M
   ENGEL, JD
   YAMAMOTO, M
TI ERYTHROID TRANSCRIPTION FACTOR GATA-1 IS ABUNDANTLY TRANSCRIBED IN MOUSE TESTIS
SO NATURE
LA English
DT Article
ID restriction endonuclease fragments; targeted mutation; binding protein; gene; expression; promoter; differentiation; enhancer; lineages; cells
AB THE transcription factor GATA-1 is a fundamental regulator of genes in haematopoietic cell lineages1,2 and belongs to a family of factors that bind to the consensus sequence WGATAR3-5. The GATA motif was originally identified in cis-regulatory regions of globin and other erythroid-specific genes6,7, but the range of genes controlled by the GATA factors has since expanded1,7-10. Members of the GATA transcription factor family share a conserved zinc-finger DNA-binding domain, but the expression profile of each GATA factor is distinct11-13 . Here we show that a testis form of murine (m)GATA-1 messenger RNA is transcribed from a promoter located 5' to the erythroid first exon, and the remaining exons (which encode the mGATA-1 protein) are used in common by both testis and erythroid transcripts. We use an anti-mGATA-1 monoclonal antibody to show that the factor expressed in erythroid cells is the same as that found in the seminiferous tubules of murine testis. The GATA-1-expressing cells in 10-week-old testis were found only in contact with the basement membrane of seminiferous tubules, suggesting that GATA-1 regulates genes during the earliest stages of spermatogenesis.
C1 TOHOKU UNIV,SCH MED,DEPT BIOCHEM,SEIRYOMACHI,AOBA KU,SENDAI,MIYAGI 980,JAPAN.
   TOHOKU UNIV,SCH MED,DEPT PATHOL,AOBA KU,SENDAI,MIYAGI 980,JAPAN.
   HIROSAKI UNIV,SCH MED,DEPT PEDIAT,HIROSAKI,AOMORI 036,JAPAN.
   NORTHWESTERN UNIV,DEPT BIOCHEM MOLEC BIOL & CELL BIOL,EVANSTON,IL 60208.
C3 Tohoku University; Tohoku University; Hirosaki University; Northwestern University
NR 23
TC 274
Z9 290
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 466
EP 468
DI 10.1038/362466a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400089
PM 8464479
DA 2026-03-10
ER

PT J
AU MANSER, E
   LEUNG, T
   SALIHUDDIN, H
   TAN, L
   LIM, L
AF MANSER, E
   LEUNG, T
   SALIHUDDIN, H
   TAN, L
   LIM, L
TI A NONRECEPTOR TYROSINE KINASE THAT INHIBITS THE GTPASE ACTIVITY OF P21(CDC42)
SO NATURE
LA English
DT Article
ID molecular-cloning; protein; gene; product; yeast; bcr; ras
AB THE Ras-related Rho subfamily of GTP-binding proteins (p21s), which includes Rho, Rac and Cdc42Hs, is implicated in different aspects of cytoskeletal organization1,2. These proteins behave like Ras (p21ras) in that their active GTP-bound form is inactivated by intrinsic hydrolysis of the nucleotide gamma-phosphate, which can be stimulated by GTPase-activating proteins (GAPs). We have previously shown that there is a diversity of GAPs that recognize this subfamily3, including n-chimaerin, which is enriched in the hippocampus4; we also detected proteins that bind these p21 proteins and seem to inhibit GTP hydrolysis. We now report the characterization of a hippocampal complementary DNA encoding a tyrosine kinase that specifically binds Cdc42Hs in its GTP-bound form. This binding is mediated by a unique sequence of 47 amino acids C-terminal to an SH3 domain and inhibits both the intrinsic and GAP-stimulated GTPase activity of Cdc42Hs. Our findings indicate that there may be a regulatory mechanism that sustains the GTP-bound active form of Cdc42Hs and which is directly linked to a tyrosine phosphorylation pathway.
C1 INST NEUROL,LONDON WC1N 1PJ,ENGLAND.
C3 University of London; University College London
RP MANSER, E (corresponding author), NATL UNIV SINGAPORE,INST MOLEC & CELL BIOL,10 KENT RIDGE CRESCENT,SINGAPORE 0511,SINGAPORE.
NR 22
TC 291
Z9 333
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 364
EP 367
DI 10.1038/363364a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700058
PM 8497321
DA 2026-03-10
ER

PT J
AU KUMAR, N
   GWIAZDA, R
   ANDERSON, RF
   FROELICH, PN
AF KUMAR, N
   GWIAZDA, R
   ANDERSON, RF
   FROELICH, PN
TI PA-231/TH-230 RATIOS IN SEDIMENTS AS A PROXY FOR PAST CHANGES IN SOUTHERN-OCEAN PRODUCTIVITY
SO NATURE
LA English
DT Article
ID high-latitude; chemical fractionation; atmospheric co2; th-230; pa-231; removal; pacific; atlantic; record; sea
AB THE biological productivity of the oceans is sensitive to changes in climate, which can affect essential factors such as nutrient and light availability. In turn, ocean productivity may influence climate by regulating the partitioning of carbon dioxide, a greenhouse gas, between the ocean and the atmosphere. Investigators have attempted to link variations in atmospheric CO2 content, recorded in ice cores1,2, to the productivity of the Southern Ocean3-6, but an unambiguous means of assessing past changes in ocean productivity has been lacking. Here we exploit established relationships between Pa-231/Th-230 ratios and particle flux7-12 to infer, from the analysis of dated sediment cores, variability through time of fluxes of particulate biogenic material exported from surface waters. Records from two cores in the Atlantic sector of the Southern Ocean indicate that ocean productivity during glacial periods was lower than at present south of the Antarctic polar front, and support earlier conclusions13-16 that the zone of maximum productivity migrated northwards during glacial conditions. Although further work at other sites is needed for an assessment of changes in total Antarctic productivity, our technique has the potential to provide this information while avoiding some of the limitations of other productivity proxies.
C1 COLUMBIA UNIV,DEPT GEOL SCI,NEW YORK,NY 10027.
C3 Columbia University
RP KUMAR, N (corresponding author), COLUMBIA UNIV,LAMONT DOHERTY EARTH OBSERV,PALISADES,NY 10964, USA.
NR 37
TC 124
Z9 132
U1 0
U2 23
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 45
EP 48
DI 10.1038/362045a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600054
DA 2026-03-10
ER

PT J
AU YAWO, H
   CHUHMA, N
AF YAWO, H
   CHUHMA, N
TI PREFERENTIAL INHIBITION OF OMEGA-CONOTOXIN-SENSITIVE PRESYNAPTIC CA2+ CHANNELS BY ADENOSINE AUTORECEPTORS
SO NATURE
LA English
DT Article
ID central-nervous-system; transmitter release; calcium currents; cells; receptor; rat; hippocampus; bradykinin; neurons; absence
AB ADENOSINE is a potent modulator of transmitter release at a variety of synapses. The adenosine A1 receptor is assumed to reside in presynaptic terminals and to function as a negative autoreceptor1. How adenosine reduces transmitter release is uncertain2; it may reduce the calcium influx during nerve terminal depolarization by either activating K+ currents3,4 or inhibiting Ca2+, currents5,6, although other mechanisms have been proposed7-9. We have directly measured intracellular Ca2+ concentrations of giant presynaptic terminals in the chick ciliary ganglion. We report here that adenosine inhibited the nerve-evoked Ca2+ influx in the terminal by activating A1 receptors. Reduced Ca2+   influx was due largely to inhibition of omega-conotoxin GVIA-sensitive Ca2+ channels in the presynaptic terminal.
RP YAWO, H (corresponding author), KYOTO UNIV,FAC MED,DEPT PHYSIOL,KYOTO 60601,JAPAN.
NR 22
TC 148
Z9 162
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 256
EP 258
DI 10.1038/365256a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100055
PM 8396730
DA 2026-03-10
ER

PT J
AU WHITE, TD
   SUWA, G
   HART, WK
   WALTER, RC
   WOLDEGABRIEL, G
   DEHEINZELIN, J
   CLARK, JD
   ASFAW, B
   VRBA, E
AF WHITE, TD
   SUWA, G
   HART, WK
   WALTER, RC
   WOLDEGABRIEL, G
   DEHEINZELIN, J
   CLARK, JD
   ASFAW, B
   VRBA, E
TI NEW DISCOVERIES OF AUSTRALOPITHECUS AT MAKA IN ETHIOPIA
SO NATURE
LA English
DT Article
ID middle awash valley; afarensis; morphology; evolution; stratigraphy; hominids; age
AB THE taxonomy of Australopithecus afarensis, the oldest known hominid species, has been a matter of debate since its description in 1978 (ref. 1). Some authorities regard all specimens assigned to A. afarensis as belonging to a single taxon2-4 whereas others regard the Tanzanian and Ethiopian specimens as each representing a different species5,6. Further controversy surrounds the issues of sexual dimorphism and locomotion among these hominids. Resolution of these problems would shed light on hominid phylogeny in general and on the ancestry of later Australopithecus and Homo. Fossils discovered in the Afar of Ethiopia in 1990 constitute the first major addition to the 3-4 million year (Myr) hominid record since the 1970s. We report here the discovery of new fossils from Maka, dated to 3.4 Myr ago, which provide powerful support for the interpretation of A. afarensis as a single, ecologically diverse, sexually dimorphic, bipedal Pliocene primate species whose known range encompassed Ethiopia and Tanzania.
C1 UNIV TOKYO,DEPT ANTHROPOL,BUNKYO KU,TOKYO 113,JAPAN.
   MIAMI UNIV,DEPT GEOL,OXFORD,OH 45056.
   INST HUMAN ORIGINS,CTR GEOCHRONOL,BERKELEY,CA 94709.
   LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545.
   INST ROYAL SCI NAT BELGIQUE,B-1040 BRUSSELS,BELGIUM.
   UNIV CALIF BERKELEY,DEPT ANTHROPOL,BERKELEY,CA 94720.
   PALEOANTHROPOL LAB,ADDIS ABABA,ETHIOPIA.
   YALE UNIV,DEPT GEOL & GEOPHYS,NEW HAVEN,CT 06511.
C3 University of Tokyo; University System of Ohio; Miami University; United States Department of Energy (DOE); Los Alamos National Laboratory; University of California System; University of California Berkeley; Yale University
RP WHITE, TD (corresponding author), UNIV CALIF BERKELEY,DEPT ANTHROPOL,HUMAN EVOLUT STUDIES LAB,BERKELEY,CA 94720, USA.
NR 43
TC 145
Z9 157
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 261
EP 265
DI 10.1038/366261a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500062
PM 8232584
DA 2026-03-10
ER

PT J
AU HARRISON, BC
   MARCHESERAGONA, SP
   GILBERT, SP
   CHENG, NQ
   STEVEN, AC
   JOHNSON, KA
AF HARRISON, BC
   MARCHESERAGONA, SP
   GILBERT, SP
   CHENG, NQ
   STEVEN, AC
   JOHNSON, KA
TI DECORATION OF THE MICROTUBULE SURFACE BY ONE KINESIN HEAD PER TUBULIN HETERODIMER
SO NATURE
LA English
DT Article
ID motility; atpase; identification
AB KINESIN, a microtubule-dependent ATPase, is believed to be involved in anterograde axonal transport. The kinesin head, which contains both microtubule and ATP binding sites, has the necessary components for the generation of force and motility1. We have used saturation binding and electron microscopy to examine the interaction of the kinesin motor domain with the microtubule surface and found that binding saturated at one kinesin head per tubulin heterodimer. Both negative staining and cryo-electron microscopy revealed a regular pattern of kinesin bound to the microtubule surface, with an axial repeat of 8 nm. Optical diffraction analysis of decorated microtubules showed a strong layer-line at this spacing, confirming that one kinesin head binds per tubulin heterodimer. The addition of Mg-ATP to the microtubule-kinesin complex resulted in the complete dissociation of kinesin from the microtubule surface.
C1 PENN STATE UNIV,DEPT MOLEC & CELL BIOL,UNIV PK,PA 16802.
   NIAMSD,STRUCT BIOL LAB,BETHESDA,MD 20892.
C3 Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; National Institutes of Health (NIH) - USA; NIH National Institute of Arthritis & Musculoskeletal & Skin Diseases (NIAMS)
NR 13
TC 77
Z9 80
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 73
EP 75
DI 10.1038/362073a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600064
PM 8095324
DA 2026-03-10
ER

PT J
AU ROZAKISADCOCK, M
   FERNLEY, R
   WADE, J
   PAWSON, T
   BOWTELL, D
AF ROZAKISADCOCK, M
   FERNLEY, R
   WADE, J
   PAWSON, T
   BOWTELL, D
TI THE SH2 AND SH3 DOMAINS OF MAMMALIAN GRB2 COUPLE THE EGF RECEPTOR TO THE RAS ACTIVATOR MSOS1
SO NATURE
LA English
DT Article
ID tyrosine kinase; protein; growth; requirement; stimulation; exchange; cells
AB MANY tyrosine kinases, including the receptors for hormones such as epidermal growth factor (EGF), nerve growth factor and insulin, transmit intracellular signals through Ras proteins1-4. Ligand binding to such receptors stimulates Ras guanine-nucleotide-exchange activity5-9 and increases the level of GTP-bound Ras10-12, suggesting that these tyrosine kinases may activate a guanine-nucleotide releasing protein (GNRP). In Caenorhabditis elegans and Drosophila, genetic studies have shown that Ras activation by tyrosine kinases requires the protein Sem-5/drk, which contains a single Src-homology (SH) 2 domain and two flanking SH3 domains13-15. Sem-5 is homologous to the mammallian protein Grb2, which binds the autophosphorylated EGF receptor and other phosphotyrosine-containing proteins such as Shc through its SH2 domain16-17. Here we show that in rodent fibroblasts, the SH3 domains of Grb2 are bound to the proline-rich carboxy-terminal tail of mSos1, a protein homologous to Drosophila Sos. Sos is required for Ras signalling18-20 and contains a central domain related to known Ras-GNRPs21-23. EGF stimulation induces binding of the Grb2-mSos1 complex to the autophosphorylated EGF receptor, and mSos1 phosphorylation. Grb2 therefore appears to link tyrosine kinases to a Ras-GNRP in mammalian cells.
C1 UNIV MELBOURNE,HOWARD FLOREY INST EXPTL PHYSIOL & MED,PARKVILLE,VIC 3052,AUSTRALIA.
   MT SINAI HOSP,SAMUEL LUNENFELD RES INST,DIV MOLEC & DEV BIOL,TORONTO M5G 1X5,ONTARIO,CANADA.
   UNIV TORONTO,DEPT MOLEC & MED GENET,TORONTO M5S 1A8,ONTARIO,CANADA.
C3 Florey Institute of Neuroscience & Mental Health; University of Melbourne; University of Toronto; Sinai Health System Toronto; Lunenfeld Tanenbaum Research Institute; University of Toronto
FU Wellcome Trust Funding Source: Medline
NR 32
TC 979
Z9 1077
U1 0
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 83
EP 85
DI 10.1038/363083a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200065
PM 8479540
DA 2026-03-10
ER

PT J
AU RABINOWITZ, DL
   GEHRELS, T
   SCOTTI, JV
   MCMILLAN, RS
   PERRY, ML
   WISNIEWSKI, W
   LARSON, SM
   HOWELL, ES
   MUELLER, BEA
AF RABINOWITZ, DL
   GEHRELS, T
   SCOTTI, JV
   MCMILLAN, RS
   PERRY, ML
   WISNIEWSKI, W
   LARSON, SM
   HOWELL, ES
   MUELLER, BEA
TI EVIDENCE FOR A NEAR-EARTH ASTEROID BELT
SO NATURE
LA English
DT Article
ID standard stars
AB IN January 1991, the 0.9-m Spacewatch telescope made the first observation1 of an asteroid outside Earth's atmosphere but in the neighbourhood of the Earth-Moon system. Since then, more than 40 Earth-approaching asteroids (defined as objects with perihelia of less than 1.3 AU) have been discovered, including 13 smaller than 50 m. Using these data, one of us (D.L.R.) has shown2 that there is an excess of Earth-approaching asteroids with diameters less than 50 m, relative to the population inferred from the distribution of larger objects. Here we argue that these smaller objects-characterized by low eccentricities, widely ranging inclinations and unusual spectral properties-form a previously undetected asteroid belt concentrated near Earth. The recent discovery of additional small Earth-approaching asteroids supports this conclusion.
C1 KITT PEAK NATL OBSERV,TUCSON,AZ 85726.
C3 National Optical Astronomy Observatory
RP RABINOWITZ, DL (corresponding author), UNIV ARIZONA,LUNAR & PLANETARY LAB,TUCSON,AZ 85721, USA.
NR 10
TC 87
Z9 91
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 704
EP 706
DI 10.1038/363704a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900050
DA 2026-03-10
ER

PT J
AU RINCHIK, EM
   BULTMAN, SJ
   HORSTHEMKE, B
   LEE, ST
   STRUNK, KM
   SPRITZ, RA
   AVIDANO, KM
   JONG, MTC
   NICHOLLS, RD
AF RINCHIK, EM
   BULTMAN, SJ
   HORSTHEMKE, B
   LEE, ST
   STRUNK, KM
   SPRITZ, RA
   AVIDANO, KM
   JONG, MTC
   NICHOLLS, RD
TI A GENE FOR THE MOUSE PINK-EYED DILUTION LOCUS AND FOR HUMAN TYPE-II OCULOCUTANEOUS ALBINISM
SO NATURE
LA English
DT Article
ID prader-willi syndrome; receptor; proteins
AB THE mouse pink-eyed dilution (p) locus on chromosome 7 is associated with defects of skin, eye and coat pigmentation1. Mutations at p cause a reduction of eumelanin (black-brown) pigment and altered morphology of black pigment granules (eumelanosomes), but have little effect on pheomelanin (yellow-red) pigment2. We show here that the human complementary DNA DN10, linked to the p locus in mice3-5, identifies the human homologue (P) of the mouse p gene, and appears to encode an integral membrane transporter protein. The expression pattern of this gene in various p mutant mice correlates with the pigmentation phenotype; moreover, an abnormally sized messenger RNA is detected in one mutant, p(un), which reverts to the normal size in p(un) revertants. The human P gene corresponds to the D15S12 locus within the chromosome segment 15q11-q13, which is typically deleted in patients with Prader-Willi and Angelman syndrome (see ref. 5 for review). These disorders are phenotypically distinct, depending on the parent of origin of the deleted chromosome5-7, but both syndromes are often associated with hypopigmentation of the skin, hair and eyes (see ref. 8 for review), and deletion of the P gene may be responsible for this hypopigmentation. In addition, we report a mutation in both copies of the human P gene in one case of tyrosinase-positive (type II) oculocutaneous albinism, recently linked to 15q11-q13 (ref. 9).
C1 UNIV FLORIDA,COLL MED,DEPT NEUROSCI,BOX 100244 JHMHC,GAINESVILLE,FL 32610.
   OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831.
   UNIV TENNESSEE,OAK RIDGE NATL LAB,OAK RIDGE GRAD SCH BIOMED SCI,OAK RIDGE,TN 37831.
   UNIV ESSEN GESAMTHSCH KLINIKUM,INST HUMANGENET,W-4300 ESSEN 1,GERMANY.
   UNIV WISCONSIN,DEPT MED GENET,MADISON,WI 53706.
C3 State University System of Florida; University of Florida; United States Department of Energy (DOE); Oak Ridge National Laboratory; United States Department of Energy (DOE); Oak Ridge National Laboratory; University of Tennessee System; University of Tennessee Knoxville; University of Duisburg Essen; University of Wisconsin System; University of Wisconsin Madison
NR 32
TC 328
Z9 355
U1 0
U2 25
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 72
EP 76
DI 10.1038/361072a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800051
PM 8421497
DA 2026-03-10
ER

PT J
AU KUBO, Y
   REUVENY, E
   SLESINGER, PA
   JAN, YN
   JAN, LY
AF KUBO, Y
   REUVENY, E
   SLESINGER, PA
   JAN, YN
   JAN, LY
TI PRIMARY STRUCTURE AND FUNCTIONAL EXPRESSION OF A RAT G-PROTEIN-COUPLED MUSCARINIC POTASSIUM CHANNEL
SO NATURE
LA English
DT Article
ID sensitive k+-channel; gamma-subunit; ion channels; inward rectification; xenopus oocytes; beta-subunit; activation; receptor; neurons; conductance
AB PARASYMPATHETIC nerve stimulation causes slowing of the heart rate by activation of muscarinic receptors and the subsequent opening of muscarinic K+ channels in the sinoatrial node and atrium1-4. This inwardly rectifying K- channel is coupled directly with G protein5-10.  Based on sequence homology with cloned inwardly rectifying K+ channels, ROMK1 (ref. 11) and IRK1 (ref. 12), we have isolated a complementary DNA for a G-protein-coupled inwardly rectifying K+ channel (GIRK1) from rat heart. The GIRK1 channel probably corresponds to the muscarinic K+ channel because (1) its functional properties resemble those of the atrial muscarinic K+ channel and (2) its messenger RNA is much more abundant in the atrium than in the ventricle. In addition, GIRK1 mRNA is expressed not only in the heart but also in the brain.
C1 UNIV CALIF SAN FRANCISCO,HOWARD HUGHES MED INST,SAN FRANCISCO,CA 94143.
   UNIV CALIF SAN FRANCISCO,DEPT PHYSIOL,SAN FRANCISCO,CA 94143.
   UNIV CALIF SAN FRANCISCO,DEPT BIOCHEM,SAN FRANCISCO,CA 94143.
C3 Howard Hughes Medical Institute; University of California System; University of California San Francisco; University of California System; University of California San Francisco; University of California System; University of California San Francisco
NR 35
TC 601
Z9 642
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 802
EP 806
DI 10.1038/364802a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100056
PM 8355805
DA 2026-03-10
ER

PT J
AU LEDWELL, JR
   WATSON, AJ
   LAW, CS
AF LEDWELL, JR
   WATSON, AJ
   LAW, CS
TI EVIDENCE FOR SLOW MIXING ACROSS THE PYCNOCLINE FROM AN OPEN-OCEAN TRACER-RELEASE EXPERIMENT
SO NATURE
LA English
DT Article
ID sulfur-hexafluoride; thermocline; basin; flow; flux; sea
AB THE distributions of heat, salt and trace substances in the ocean thermocline depend on mixing along and across surfaces of equal density (isopycnal and diapycnal mixing, respectively). Measurements of the invasion of anthropogenic tracers, such as bomb tritium and He-3 (see, for example, refs 1 and 2), have indicated that isopycnal processes dominate diapycnal mixing, and turbulence measurements have suggested that diapycnal mixing is small3,4, but it has not been possible to measure accurately the diapycnal diffusivity. Here we report such a measurement, obtained from the vertical dispersal of a patch of the inert compound SF6 released in the open ocean. The diapycnal diffusivity, averaged over hundreds of kilometres and five months, was 0.11 +/- 0.02 cm2 S-1, confirming previous estimates1-4. Such a low diffusivity can support only a rather small diapycnal flux of nitrate into the euphotic zone; it justifies the neglect of diapycnal mixing in dynamic models of the thermocline25-27, and implies that heat, salt and tracers must penetrate the thermocline mostly by transport along, rather than across, density surfaces.
C1 PLYMOUTH MARINE LAB, PLYMOUTH PL1 3DH, ENGLAND.
C3 Plymouth Marine Laboratory
RP LEDWELL, JR (corresponding author), WOODS HOLE OCEANOG INST, WOODS HOLE, MA 02543 USA.
NR 27
TC 846
Z9 911
U1 0
U2 96
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 701
EP 703
DI 10.1038/364701a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700051
DA 2026-03-10
ER

PT J
AU BURNOL, AF
   MARGOTTIN, F
   HUET, J
   ALMOUZNI, G
   PRIOLEAU, MN
   MECHALI, M
   SENTENAC, A
AF BURNOL, AF
   MARGOTTIN, F
   HUET, J
   ALMOUZNI, G
   PRIOLEAU, MN
   MECHALI, M
   SENTENAC, A
TI TFIIIC RELIEVES REPRESSION OF U6 SNRNA TRANSCRIPTION BY CHROMATIN
SO NATURE
LA English
DT Article
ID rna polymerase-c; saccharomyces-cerevisiae; yeast; dna; gene; invitro
AB THE U6 small nuclear (sn)RNA gene (SNR6) from the yeast Saccharomyces cerevisiae is transcribed by RNA polymerase III in vivo1. This gene is unusual in having a TATA box at position -30, and an essential B-block element located downstream of the T-rich termination signal2,3. The B block is one of the two intragenic promoter elements of transfer RNA genes that are recognized by transcription factor (TF)IIIC (ref. 4). But accurate in vitro transcription of yeast U6 snRNA gene by PolIII in a purified system requires only TFIIIB components, including the TATA-box binding protein TBP5. Here we report that, after nucleosome reconstitution or chromatin assembly, U6 snRNA synthesis becomes dependent on TFIIIC and on the integrity of the B-block element. This observation resolves an apparent paradox between in vitro and in vivo results concerning the necessity of the downstream B-block element3,5 and sheds light on a new role of TFIIIC in gene activation.
C1 INST JACQUES MONOD,EMBRYOL MOLEC LAB,F-75251 PARIS,FRANCE.
C3 Universite Paris Cite
RP BURNOL, AF (corresponding author), CTR ETUD SACLAY,DEPT BIOL CELLULAIRE & MOLEC,SERV BIOCHIM & GENET MOLEC,F-91191 GIF SUR YVETTE,FRANCE.
NR 20
TC 95
Z9 99
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 475
EP 477
DI 10.1038/362475a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400092
PM 8464480
DA 2026-03-10
ER

PT J
AU VERHEIJ, C
   BAKKER, CE
   DEGRAAFF, E
   KEULEMANS, J
   WILLEMSEN, R
   VERKERK, AJMH
   GALJAARD, H
   REUSER, AJJ
   HOOGEVEEN, AT
   OOSTRA, BA
AF VERHEIJ, C
   BAKKER, CE
   DEGRAAFF, E
   KEULEMANS, J
   WILLEMSEN, R
   VERKERK, AJMH
   GALJAARD, H
   REUSER, AJJ
   HOOGEVEEN, AT
   OOSTRA, BA
TI CHARACTERIZATION AND LOCALIZATION OF THE FMR-1 GENE-PRODUCT ASSOCIATED WITH FRAGILE-X SYNDROME
SO NATURE
LA English
DT Article
ID expression; purification; cells
AB THE fragile X syndrome is the most frequent form of inherited mental retardation after Down's syndrome, having an incidence of one in 1,250 males1,2. The fragile X syndrome results from amplification of the CGG repeat found in the FMR-1 gene3-6. This CGG repeat shows length variation in normal individuals and is increased significantly in both carriers and patients3-6; it is located 250 base pairs distal to a CpG island6 which is hypermethylated in fragile X patients4-7. The methylation probably results in downregulation of FMR-1 gene expression8. No information can be deduced about the function of the FMR-1 protein from its predicted sequence. Here we investigate the nature and function of the protein encoded by the FMR-1 gene using polyclonal antibodies raised against the predicted amino-acid sequences. Four different protein products, possibly resulting from alternative splicing, have been identified by immunoblotting in lymphoblastoid cell lines of healthy individuals. All these proteins were missing in cell lines from patients not expressing FMR-1 messenger RNA. The intracellular localization of the FMR-1 gene products was investigated by transient expression in COS-1 cells and found to be cytoplasmic. Localization was also predominantly cytoplasmic in the epithelium of the oesophagus, but in some cells was obviously nuclear.
C1 ERASMUS UNIV ROTTERDAM,MGC DEPT CLIN GENET,POB 1738,3000 DR ROTTERDAM,NETHERLANDS.
C3 Erasmus University Rotterdam; Erasmus University Rotterdam - Excl Erasmus MC
NR 17
TC 296
Z9 330
U1 0
U2 14
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 722
EP 724
DI 10.1038/363722a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900056
PM 8515814
DA 2026-03-10
ER

PT J
AU BLUTH, GJS
   SCHNETZLER, CC
   KRUEGER, AJ
   WALTER, LS
AF BLUTH, GJS
   SCHNETZLER, CC
   KRUEGER, AJ
   WALTER, LS
TI THE CONTRIBUTION OF EXPLOSIVE VOLCANISM TO GLOBAL ATMOSPHERIC SULFUR-DIOXIDE CONCENTRATIONS
SO NATURE
LA English
DT Article
ID sulfur-dioxide; ice-sheet; eruptions; clouds; so2
AB SULPHUR dioxide from volcanic eruptions may have a significant effect on the Earth's climate and atmospheric chemistry, and it is therefore important to quantify outgassing rates for all types of volcanic activity. Non-explosive volcanoes (for example, Mount Etna) outgas at relatively constant rates, providing an annual flux of about 9 million tons (Mt) SO2 (ref. 1). By contrast, the outgassing from volcanoes prone to explosive eruptions (such as Mount Pinatubo) is sporadic and much more difficult to quantify. The total annual volcanic SO2 flux is therefore poorly constrained, with ground-based estimates1-8 ranging from 1.5 to 50 Mt-up to one-quarter of the estimated current anthropogenic contribution. The Total Ozone Mapping Spectrometer aboard the NASA satellite Nimbus 7 recorded SO2 emissions from explosive eruptions from November 1978 to May 1993. We use these data to show that the annual flux from explosive volcanism is of the order of 4 Mt SO2, less than half of the non-explosive output. Thus it seems that the total volcanic emission of SO2 to the Earth's atmosphere is about 13 Mt yr-1, which is only 5-10% of the current anthropogenic flux.
C1 UNIV MARYLAND,DEPT GEOG,COLL PK,MD 20742.
   NASA,GODDARD SPACE FLIGHT CTR,EARTH SCI DIRECTORATE,GREENBELT,MD 20771.
C3 University System of Maryland; University of Maryland College Park; National Aeronautics & Space Administration (NASA); NASA Goddard Space Flight Center
RP BLUTH, GJS (corresponding author), NASA,GODDARD SPACE FLIGHT CTR,UNIV SPACE RES ASSOC,CODE 921,GREENBELT,MD 20771, USA.
NR 18
TC 176
Z9 186
U1 0
U2 26
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 327
EP 329
DI 10.1038/366327a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500043
DA 2026-03-10
ER

PT J
AU FEIGENSPAN, A
   WASSLE, H
   BORMANN, J
AF FEIGENSPAN, A
   WASSLE, H
   BORMANN, J
TI PHARMACOLOGY OF GABA RECEPTOR CL- CHANNELS IN RAT RETINAL BIPOLAR CELLS
SO NATURE
LA English
DT Article
ID gamma-aminobutyric-acid; glycine receptor; patch-clamp; functional expression; membrane patches; xenopus oocytes; subunit; currents; bicuculline; strychnine
AB Gamma-AMINOBUTYRIC acid (GABA), a major inhibitory neurotransmitter in the mammalian nervous system, is known to operate bicuculline-sensitive Cl- channels through GABA(A) receptors and bicuculline-insensitive cation channels through GABA(B) receptors1,2. Recent observations indicate that the retina may contain GABA receptors with unusual pharmacological properties3-5. Here we report that GABA gates bicuculline-insensitive Cl- channels in rod bipolar cells of the rat retina, which were not modulated by flunitrazepam, pentobarbital and alphaxalone and were only slightly blocked by picrotoxinin. Moreover, the GABA(B) receptor agonist baclofen, and the antagonist 2-hydroxysaclofen had no effect. The underlying single-channel conductance was 7 pS and the open time 150 ms. These values are clearly different from those obtained for GABA(A) receptor channels recorded in other neurons of the same preparation, and in other parts of the brain1,6-8. The bicuculline- and baclofen-insensitive GABA receptors were activated selectively by the GABA analogue cis-4-aminocrotonic acid (CACA)9. Hence they may be similar to those receptors termed GABA(C) receptors10.
C1 MAX PLANCK INST HIRNFORSCH,DEUTSCHORDENSTR 46,W-6000 FRANKFURT 71,GERMANY.
C3 Max Planck Society
NR 26
TC 365
Z9 392
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 159
EP 162
DI 10.1038/361159a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600061
PM 7678450
DA 2026-03-10
ER

PT J
AU LI, JC
   ROSS, DK
AF LI, JC
   ROSS, DK
TI EVIDENCE FOR 2 KINDS OF HYDROGEN-BOND IN ICE
SO NATURE
LA English
DT Article
ID incoherent neutron-scattering; water; ih; model; ix; vi
AB DESPITE its simplicity at the molecular level, water is a complex and poorly understood liquid1. The reasons for this centre around the existence of a dynamic hydrogen-bonded network throughout the liquid. Attempts to describe the structure of liquid water have tended to invoke either continuum models such as the 'distorted-bond' model2, which assumes that the hydrogen-bonded structure relaxes on a timescale similar to that in other liquids, and mixture models, such as the 'flickering-cluster' model3, which postulate the coexistence of two or more long-lived structures in the liquid. Here we analyse inelastic neutron-scattering spectra for the ice I solid phase of water, which provide evidence for the existence of two different kinds of hydrogen-bond, of different strengths, in the solid. A model in which strong and weak hydrogen-bonds in the ratio of about 2:1 are randomly distributed throughout the network is able to reproduce the neutron spectra. If we can assume that the same kind of bimodal hydrogen-bonding exists in the liquid state, our model may be able to explain several of the anomalous properties of liquid water, such as the large specific heat and the unusual behaviour of water in thin films and clusters.
C1 UNIV BIRMINGHAM,SCH PHYS & SPACE RES,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND.
C3 University of Birmingham
RP LI, JC (corresponding author), UNIV SALFORD,DEPT PURE & APPL PHYS,SALFORD M6 4WT,ENGLAND.
NR 24
TC 175
Z9 186
U1 1
U2 29
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 327
EP 329
DI 10.1038/365327a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600047
DA 2026-03-10
ER

PT J
AU ROBERTSON, HM
AF ROBERTSON, HM
TI THE MARINER TRANSPOSABLE ELEMENT IS WIDESPREAD IN INSECTS
SO NATURE
LA English
DT Article
ID drosophila-melanogaster; dna
AB THE mariner transposable element is a small member of the short inverted terminal repeat class thought to transpose through a DNA intermediate1. Originally described in Drosophila mauritiana2, it is now known in several species of the family Drosophilidae3,4, and in a moth Hyalophora cecropia5. Here I use primers designed to represent regions of amino-acid conservation between the putative transposase genes of the D. mauritiana and H. cecropia elements to amplify equivalent regions of presumed mariner elements from ten other insects representing six additional orders, including the malaria-vector mosquito, Anopheles gambiae. Sequences of multiple clones from each species reveal a diverse array of mariner elements, with multiple subfamilies in the genomes of some insects, indicating both vertical inheritance and horizontal transfers. An intact open reading frame in at least one clone from each species suggests each may carry functional transposable elements. Therefore the mariner element is an excellent candidate for development of genetic transformation systems for non-drosophilid insects, and possibly other arthropods.
RP ROBERTSON, HM (corresponding author), UNIV ILLINOIS,DEPT ENTOMOL,505 S GOODWIN AVE,URBANA,IL 61801, USA.
NR 25
TC 344
Z9 370
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 241
EP 245
DI 10.1038/362241a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600055
PM 8384700
DA 2026-03-10
ER

PT J
AU WALSH, C
   CEPKO, CL
AF WALSH, C
   CEPKO, CL
TI CLONAL DISPERSION IN PROLIFERATIVE LAYERS OF DEVELOPING CEREBRAL-CORTEX
SO NATURE
LA English
DT Article
ID migration patterns
AB IN the adult cerebral cortex, many retrovirally labelled clones are widely dispersed1, though the mechanisms of this dispersion are not well understood. Here we investigate the temporal sequence of clonal dispersion after labelling progenitors of rat cortical cells with replication-incompetent retroviruses at early stages of cortical neurogenesis, 14-15 days after conception (E14/15). The location of labelled daughter cells was determined 3, 6 or 10 days later. Labelled sibling cells were radially arrayed three days after infection (E18). In contrast, by six days after infection (E20/21), 43% of cortical clones were dispersed non-radially by at least 500 mum. Four of these widespread clones were dispersed longitudinally by greater-than-or-equal-to 2 mm, implying sustained rates of dispersion of > 15 mum per hour. Dispersed sibling cells occurred within proliferative zones of the forebrain in 35% of widely dispersed clones, suggesting that some dispersion reflects movement of dividing cells. Some clones dispersed beyond the neocortex into the olfactory bulb. Progenitor cell dispersion represents a previously unrecognized mode of migration by which sibling cells become widely dispersed in the developing forebrain.
C1 HARVARD UNIV,SCH MED,DEPT GENET,BOSTON,MA 02115.
   MASSACHUSETTS GEN HOSP,DEPT NEUROL,BOSTON,MA 02114.
C3 Harvard University; Harvard Medical School; Harvard University; Harvard University Medical Affiliates; Massachusetts General Hospital
NR 17
TC 206
Z9 228
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 632
EP 635
DI 10.1038/362632a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800048
PM 8464513
DA 2026-03-10
ER

PT J
AU GOGUEN, B
   KEDERSHA, N
AF GOGUEN, B
   KEDERSHA, N
TI CLONOGENIC CYTOTOXICITY TESTING BY MICRODROP ENCAPSULATION
SO NATURE
LA English
DT Article
ID cell
C1 IMMUNOGEN INC,CAMBRIDGE,MA 02139.
C3 ImmunoGen, Inc.
RP GOGUEN, B (corresponding author), ONE CELL SYST INC,100 INMAN ST,CAMBRIDGE,MA 02139, USA.
NR 7
TC 10
Z9 13
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 189
EP 190
DI 10.1038/363189a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100058
PM 8483506
DA 2026-03-10
ER

PT J
AU HARRISON, JF
   HALL, HG
AF HARRISON, JF
   HALL, HG
TI AFRICAN EUROPEAN HONEYBEE HYBRIDS HAVE LOW NONINTERMEDIATE METABOLIC CAPACITIES
SO NATURE
LA English
DT Article
ID apis-mellifera; mitochondrial-dna; bees; hybridization; races
AB BECAUSE of a number of behavioural, ecological and physiological factors, African honeybees (Apis mellifera scutellata) are better adapted to tropical environments than European bees. African bees achieve higher rates of reproduction and colony growth partly by collecting more pollen relative to nectar1 and by allocating more nutrients to brood rearing2. African colonies generate more swarms3,4 which travel far greater distances5. These adaptive traits have been dramatically manifested in the neotropics: African bees have formed large expanding feral populations, whereas few European bees have survived outside apiaries6. The feral populations consist of African matrilines7-9 that have not hybridized extensively with European drones from apiaries10. Perhaps because of their European heritage, hybrids are poorly adapted to the tropics and thus do not survive. European matrilines, however, do not become part of the feral population, even after repeated backcrossing with feral African drones7-10. Conceivably, negative heterosis could further reduce hybrid survival, where European maternal factors are particularly detrimental7. We report here physiological findings consistent with these possibilities. Mass-specific metabolic capacities were higher in African bees than in European bees and were low and nonintermediate in hybrids. Thus, higher metabolic and flight capacities may contribute to African bees' competitive advantages in the tropics.
C1 UNIV FLORIDA,DEPT ENTOMOL & NEMATOL,GAINESVILLE,FL 32611.
C3 State University System of Florida; University of Florida
RP HARRISON, JF (corresponding author), ARIZONA STATE UNIV,DEPT ZOOL,TEMPE,AZ 85287, USA.
NR 30
TC 90
Z9 96
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 258
EP 260
DI 10.1038/363258a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600051
DA 2026-03-10
ER

PT J
AU KITSBERG, D
   SELIG, S
   BRANDEIS, M
   SIMON, I
   KESHET, I
   DRISCOLL, DJ
   NICHOLLS, RD
   CEDAR, H
AF KITSBERG, D
   SELIG, S
   BRANDEIS, M
   SIMON, I
   KESHET, I
   DRISCOLL, DJ
   NICHOLLS, RD
   CEDAR, H
TI ALLELE-SPECIFIC REPLICATION TIMING OF IMPRINTED GENE REGIONS
SO NATURE
LA English
DT Article
ID growth factor-ii; human h19 gene; prader-willi; insitu hybridization; dna methylation; x-chromosome; tme locus; mouse; expression; angelman
AB SEVERAL lines of evidence suggest that the paternal and maternal genomes may have different expression patterns in the developing organism1 and this has been confirmed by the identification of endogenous genes that are parentally imprinted in the mouse2-5. little is known about the precise mechanisms involved in the process, but structural differences between the two alleles must somehow provide cis-acting signals for directing parental-specific transcription. Cell-cycle replication time is one parameter that has been shown to be associated with both tissue-specific gene expression6,7 and the allele-specific transcription patterns of the X chromosomes in female cells8. For this reason we have examined the replication timing patterns for the chromosomal regions containing the imprinted genes Igf2, Igf2r, Hl9 and Snrpn in the mouse. At all of these sites, and their corresponding positions in the human genome, the two homologous alleles replicate asynchronously and it is always the paternal allele that is early-replicating. Thus imprinted genes appear to be embedded in large DNA domains with differential replication patterns, which may provide a structural imprint for parental identity.
C1 UNIV FLORIDA,COLL MED,DIV GENET,GAINESVILLE,FL 32610.
   UNIV FLORIDA,COLL MED,DEPT NEUROSCI,GAINESVILLE,FL 32610.
   UNIV FLORIDA,COLL MED,DEPT PEDIAT,GAINESVILLE,FL 32610.
C3 State University System of Florida; University of Florida; State University System of Florida; University of Florida; State University System of Florida; University of Florida
RP KITSBERG, D (corresponding author), HEBREW UNIV JERUSALEM,SCH MED,DEPT CELLULAR BIOCHEM,IL-91010 JERUSALEM,ISRAEL.
NR 39
TC 346
Z9 378
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 459
EP 463
DI 10.1038/364459a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000060
PM 8332218
DA 2026-03-10
ER

PT J
AU FARQUHAR, GD
   LLOYD, J
   TAYLOR, JA
   FLANAGAN, LB
   SYVERTSEN, JP
   HUBICK, KT
   WONG, SC
   EHLERINGER, JR
AF FARQUHAR, GD
   LLOYD, J
   TAYLOR, JA
   FLANAGAN, LB
   SYVERTSEN, JP
   HUBICK, KT
   WONG, SC
   EHLERINGER, JR
TI VEGETATION EFFECTS ON THE ISOTOPE COMPOSITION OF OXYGEN IN ATMOSPHERIC CO2
SO NATURE
LA English
DT Article
ID carbon; water; soil; economy; growth; model
AB THE O-18/O-16 ratio in atmospheric CO2 is a signal dominated by CO2 exchange with the terrestrial biosphere and it has considerable potential to resolve the current importance of the oceans and individual terrestrial biomes as net sinks for anthropogenic CO2. Fractionation of the oxygen isotopes of CO2 occurs in plants owing to differential diffusion of (COO)-O-18-O-16 and (CO2)-O-16 and to isotope effects in oxygen exchange with chloroplast water. Here we investigate the consequences of these effects for the global distribution of oxygen isotopes in CO2. We predict that O-18 isotopic exchange fluxes, especially between the atmosphere and terrestrial biosphere, are large, with considerable spatial variation. Near 70-degrees-N, where precipitation (and soil water) is most depleted in O-18, photosynthesis and respiration both deplete the atmospheric CO2 of O-18. This provides an explanation for the depletion of O-18 in atmospheric CO2 at high northern latitudes1.
C1 AUSTRALIAN NATL UNIV,INST ADV STUDIES,CTR RESOURCE & ENVIRONM STUDIES,CANBERRA,ACT 2601,AUSTRALIA.
   CARLETON UNIV,DEPT BIOL,OTTAWA K1S 5B6,ONTARIO,CANADA.
   UNIV FLORIDA,CTR AGR RES & EDUC,CTR CITRUS RES & EDUC,LAKE ALFRED,FL 33850.
   UNIV UTAH,DEPT BIOL,SALT LAKE CITY,UT 84112.
C3 Australian National University; Carleton University; State University System of Florida; University of Florida; Utah System of Higher Education; University of Utah
RP FARQUHAR, GD (corresponding author), AUSTRALIAN NATL UNIV,RES SCH BIOL SCI,INST ADV STUDIES,PLANT ENVIRONM BIOL GRP,GPO BOX 475,CANBERRA,ACT 2601,AUSTRALIA.
NR 39
TC 342
Z9 381
U1 2
U2 104
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 439
EP 443
DI 10.1038/363439a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800055
DA 2026-03-10
ER

PT J
AU DUNG, VV
   GIAO, PM
   CHINH, NN
   TUOC, D
   ARCTANDER, P
   MACKINNON, J
AF DUNG, VV
   GIAO, PM
   CHINH, NN
   TUOC, D
   ARCTANDER, P
   MACKINNON, J
TI A NEW SPECIES OF LIVING BOVID FROM VIETNAM
SO NATURE
LA English
DT Article
AB IN May 1992 a joint survey by the Ministry of Forestry and World Wide Fund for Nature of the Vu Quang Nature Reserve, Ha tinh province, found three sets of long straight horns of a new bovid (Mammalia, Artiodactyla) in hunters' houses1. None of the specimens had dentition. On four follow-up visits by Vietnamese scientists new specimens were discovered and surveys of forests in neighbouring Nghe an province revealed more localities and some partial specimens. In all, we have examined more than 20 specimens. Three have complete upper skulls and dentitions, two have lower jaws and dentitions. Three complete skins have been collected. The specimens are distinct in appearance, morphology and DNA sequence and cannot be ascribed to any known genus. Only two bovid genera are known from this part of Asia, Bos and Naemorhedus = Capricornis2,3. A new genus and species are therefore described. Such a discovery is of great significance. It has been more than 50 years since any comparable find of a large mammal species has been made; the last being the kouprey Bos = Novibos sauveli, another Indochinese bovid (Urbain, 1937). Moreover, the bovids (cattle, goats and antelopes) are a mammal family of great value to mankind. Many species have proven or potential value for domestication or cross-breeding. A three-month field study is planned to observe the living animal.
C1 ASIAN BUR CONSERVAT, 18-E CAPITAL BLDG, 175-191 LOCKHART RD, WANCHAI, HONG KONG SAR.
   MINIST FORESTRY, INST FOREST INVENTORY & PLANNING, HANOI, VIETNAM.
NR 10
TC 94
Z9 101
U1 1
U2 29
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 443
EP 445
DI 10.1038/363443a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800056
DA 2026-03-10
ER

PT J
AU LYNE, AG
   BIGGS, JD
   HARRISON, PA
   BAILES, M
AF LYNE, AG
   BIGGS, JD
   HARRISON, PA
   BAILES, M
TI A LONG-PERIOD GLOBULAR-CLUSTER PULSAR IN AN ECLIPSING BINARY-SYSTEM
SO NATURE
LA English
DT Article
ID x-ray binary; millisecond pulsar; radio pulsars; origin
AB PULSARS that are members of binary systems in globular clusters are all rapidly rotating, and it is assumed that they have been spun up by accretion from binary companions. Here we report an exception: PSR1718-19, in the globular cluster NGC6342, is in a 6.2-hour eclipsing binary system, but has the relatively long period of 1 s. Its magnetic field is strong, approximately 10(12) G, and its spin-down age is small, approximately 10 Myr. Furthermore, the mass of its companion is only 0.1-0.2 solar masses (M.). The eclipses show that the binary system is embedded in a cloud of material which must have been ejected from the companion star, although calculations suggest that the companion is well inside its Roche lobe. The pulsar's radiation may be causing expulsion of material beyond the Roche lobe, as in the ablating binary systems containing PSR-1744 - 24A and PSR1957 + 20, even though the incident flux at the companion is orders of magnitude smaller than in these cases. Pulsars may therefore have a much greater influence on their companions than has been supposed.
RP LYNE, AG (corresponding author), UNIV MANCHESTER,NUFFIELD RADIO ASTRON LABS,JODRELL BANK,MACCLESFIELD SK11 9DL,CHESHIRE,ENGLAND.
NR 20
TC 65
Z9 73
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 47
EP 49
DI 10.1038/361047a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800041
DA 2026-03-10
ER

PT J
AU SETO, E
   LEWIS, B
   SHENK, T
AF SETO, E
   LEWIS, B
   SHENK, T
TI INTERACTION BETWEEN TRANSCRIPTION FACTORS SP1 AND YY1
SO NATURE
LA English
DT Article
ID synergistic activation; initiator; enhancer; protein; domains; transactivator; repression; expression; elements; invitro
AB A BASAL level of transcription is usually observed when all but a small region of DNA has been deleted from a eukaryotic gene promoter. These promoter elements, which are necessary and sufficient for specific transcription initiation, are referred to as minimal or core promoter elements. One element that is commonly present in a core promoter is the initiator. It has been demonstrated that the presence of Sp1 binding sites can greatly enhance the level of transcription initiation at initiator elements1-4. A binding site for the YY1 transcription factor, located at the initiation site of the adeno-associated virus P5 promoter, functions as an initiator element; a synergistic enhancement of its activity is observed in vitro when upstream Sp1 binding sites are present3. Here we report that this synergistic activation probably occurs through protein-protein interactions.
C1 PRINCETON UNIV,HOWARD HUGHES MED INST,DEPT MOLEC BIOL,PRINCETON,NJ 08544.
C3 Howard Hughes Medical Institute; Princeton University
RP SETO, E (corresponding author), UNIV TEXAS,HLTH SCI CTR,CTR MOLEC MED,INST BIOTECHNOL,DEPT CELLULAR & STRUCT BIOL,SAN ANTONIO,TX 78245, USA.
NR 20
TC 268
Z9 293
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 462
EP 464
DI 10.1038/365462a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300063
PM 8003102
DA 2026-03-10
ER

PT J
AU MELOSH, HJ
   SCHENK, P
AF MELOSH, HJ
   SCHENK, P
TI SPLIT COMETS AND THE ORIGIN OF CRATER CHAINS ON GANYMEDE AND CALLISTO
SO NATURE
LA English
DT Article
ID body
AB WHEN the Voyager 1 spacecraft flew through the jovian system in January 1979, it returned images of several prominent chains of impact craters on the surface of the moon Callisto (Fig. 1). These impressively straight chains, or catenae, are composed of between 4 and 25 craters, and are up to 620 km long. They were initially thought to be secondary craters produced by debris from a larger primary impact1, but detailed searches for source craters have been largely unsuccessful: a satisfactory explanation for the crater chains has yet to be found. Inspired by the recent observations of comet Shoemaker-Levy 9, which split into a line of about 20 fragments as it swept past Jupiter2, we suggest that the impact of previous split comets might be responsible for at least some of the catenae on Callisto. In support of this hypothesis, we find that nearly all of Callisto's crater chains are on the Jupiter-facing hemisphere, as are an additional three catenae that we have found on Ganymede. We present a simple model of tidal breakup which both reproduces the range of observed chain lengths and indicates that the parent comets responsible for the Callisto catenae were typically no more than about 10 km in diameter.
C1 LUNAR & PLANETARY INST,HOUSTON,TX 77058.
RP MELOSH, HJ (corresponding author), UNIV ARIZONA,LUNAR & PLANETARY LAB,TUCSON,AZ 85721, USA.
NR 10
TC 49
Z9 55
U1 1
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 731
EP 733
DI 10.1038/365731a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200054
DA 2026-03-10
ER

PT J
AU JACOBS, DK
   SAHAGIAN, DL
AF JACOBS, DK
   SAHAGIAN, DL
TI CLIMATE-INDUCED FLUCTUATIONS IN SEA-LEVEL DURING NON-GLACIAL TIMES
SO NATURE
LA English
DT Article
ID triassic platform carbonates; eastern sahara; holocene; lakes; bp; remains; cycle; niger; state
AB DURING periods of time when the Earth supports ice caps, sea level fluctuates periodically at intervals of 10(4)-10(5) yr, with amplitudes of tens to more than 100 metres. These fluctuations result from expansions and contractions of continental ice sheets that occur in phase with the Milankovitch periodicities of the Earth's orbit1,2.  Smaller-amplitude sea-level fluctuations associated with Milankovitch periodicities are also evident during warm periods, such as the Late Triassic3-5, which lack strong evidence for continental glaciation6. We argue here that, in times of limited ice volume, periodic climate-induced changes in lake and groundwater storage have the potential to produce small fluctuations in sea level. This mechanism could contribute a small component of the sea-level change observed in the Quaternary period, and may dominate the Milankovitch eustatic sea-level signal during earlier periods with limited ice volume6. We present evidence of contemporaneous Milankovitch periodicities in Late Triassic lake sediments7 and sea-level fluctuation3-5 which support the causal link between lake water storage and eustasy.
C1 OHIO STATE UNIV,DEPT GEOL SCI,COLUMBUS,OH 43210.
   OHIO STATE UNIV,BYRD POLAR RES CTR,COLUMBUS,OH 43210.
C3 University System of Ohio; Ohio State University; University System of Ohio; Ohio State University
RP JACOBS, DK (corresponding author), AMER MUSEUM NAT HIST,DEPT INVERTEBRATES,CENT PK W & 79TH ST,NEW YORK,NY 10024, USA.
NR 39
TC 137
Z9 152
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 710
EP 712
DI 10.1038/361710a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900050
DA 2026-03-10
ER

PT J
AU KILLEEN, N
   LITTMAN, DR
AF KILLEEN, N
   LITTMAN, DR
TI HELPER T-CELL DEVELOPMENT IN THE ABSENCE OF CD4-P56(LCK) ASSOCIATION
SO NATURE
LA English
DT Article
ID major histocompatibility complex; protein-tyrosine kinase; antigen receptor; transgenic mice; physical association; signal transduction; cytoplasmic domains; positive selection; alpha-3 domain; lymphocytes-t
AB THE CD4 and CD8 glycoproteins are expressed on helper and cytoxic T lymphocytes, respectively, and have important functions in the differentiation and activation of these cells1-8. These molecules are thought to participate in signal transduction by binding to the same class II or class I major histocompatibility complex molecules that are engaged by the T-cell antigen receptor9-13. The cytoplasmic domains of both CD4 and CD8 interact with the protein tyrosine kinase p56lck (refs 14-17), an essential participant in thymocyte maturation18 and T-cell activation19. This interaction is required for effective in vitro responses to antigen5-8, suggesting that signalling through p56lck is a major function of CD4 and CD8. Here we investigate the role of the CD4-p56lck interaction during T-lymphocyte development by expressing wild-type and truncated products of CD4 transgenes in mice that lack endogenous CD4 and hence have defective helper-cell development3,4. We find that transgenic CD4, which cannot associate with p56lck, can nevertheless rescue the helper-cell lineage when overexpressed. This result indicates that the contribution of CD4 to lineage development need not involve signalling through p56lck, and provides insight into the general function of CD4 and CD8.
C1 UNIV CALIF SAN FRANCISCO, DEPT MICROBIOL & IMMUNOL, SAN FRANCISCO, CA 94143 USA.
   UNIV CALIF SAN FRANCISCO, DEPT BIOCHEM & BIOPHYS, SAN FRANCISCO, CA 94143 USA.
C3 University of California System; University of California San Francisco; University of California System; University of California San Francisco
RP KILLEEN, N (corresponding author), UNIV CALIF SAN FRANCISCO, HOWARD HUGHES MED INST, SAN FRANCISCO, CA 94143 USA.
NR 37
TC 126
Z9 131
U1 0
U2 0
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 729
EP 732
DI 10.1038/364729a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700062
PM 8355789
DA 2026-03-10
ER

PT J
AU SOLESSIO, E
   ENGBRETSON, GA
AF SOLESSIO, E
   ENGBRETSON, GA
TI ANTAGONISTIC CHROMATIC MECHANISMS IN PHOTORECEPTORS OF THE PARIETAL EYE OF LIZARDS
SO NATURE
LA English
DT Article
ID pineal organ; cells
AB PHOTORECEPTORS are the first in the chain of neurons that process visual information. In lateral eyes of vertebrates, light hyperpolarizes rod and cone photoreceptors that synapse onto bipolar and horizontal cells in the first synaptic layer of the retina. The sign of the photoreceptor signal is either conserved or inverted in bipolar cells, resulting in chromatically dependent depolarizing and hyperpolarizing responses to visual stimuli. Visual information is then conveyed to the second synaptic layer for encoding and transmission to the brain by ganglion cells. The parietal (third) eve of lizards does not contain bipolar cells or other interneurons. Photoreceptors synapse directly onto ganglion cells1-4 and yet, even in the absence of interneurons, antagonistic chromatic mechanisms modulate the ganglion cell responses5,6. We report here that chromatic antagonism in the third eye originates in the chromatically dependent hyperpolarizing and depolarizing response of the photoreceptors to light. We also suggest that the antagonistic nature of these photoresponses may provide lizards with a mechanism for the enhanced detection of dawn and dusk.
C1 SYRACUSE UNIV,DEPT BIOENGN & NEUROSCI,SYRACUSE,NY 13244.
C3 Syracuse University
RP SOLESSIO, E (corresponding author), SYRACUSE UNIV,INST SENSORY RES,SYRACUSE,NY 13244, USA.
NR 21
TC 99
Z9 110
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 442
EP 445
DI 10.1038/364442a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000054
PM 8332214
DA 2026-03-10
ER

PT J
AU CROZAT, A
   AMAN, P
   MANDAHL, N
   RON, D
AF CROZAT, A
   AMAN, P
   MANDAHL, N
   RON, D
TI FUSION OF CHOP TO A NOVEL RNA-BINDING PROTEIN IN HUMAN MYXOID LIPOSARCOMA
SO NATURE
LA English
DT Article
ID single gene; expression; sequence; domain; cells
AB HUMAN myxoid liposarcomas contain a characteristic chromosomal translocation, t(12;16)(q13;p11)1,2, that is associated with a structural rearrangement of the gene encoding CHOP 3, a growth arrest and DNA-damage inducible member of the C/EBP family of transcription factors4,5 residing on 12q13.1 6. Using a CHOP-specific complementary probe and antiserum we report here the presence of an abnormal CHOP transcript and protein in these tumours. Cloning of the translocation-associated CHOP gene product revealed a fusion between CHOP and a gene provisionally named TLS (translocated in liposarcoma). TLS is a novel nuclear RNA-binding protein with extensive sequence similarity to EWS7, the product of a gene commonly translocated in Ewing's sarcoma. In TLS-CHOP the RNA-binding domain of TLS is replaced by the DNA-binding and leucine zipper dimerization domain of CHOP. Targeting of a conserved effector domain of RNA-binding proteins to DNA may play a role in tumour formation.
C1 NYU MED CTR,DEPT CELL BIOL,NEW YORK,NY 10016.
   NYU MED CTR,KAPLAN CANC CTR,NEW YORK,NY 10016.
   UNIV LUND HOSP,DEPT CLIN GENET,S-22185 LUND,SWEDEN.
C3 New York University; New York University; Lund University; Skane University Hospital
RP CROZAT, A (corresponding author), NYU MED CTR,DEPT MED,NEW YORK,NY 10016, USA.
NR 18
TC 787
Z9 863
U1 1
U2 24
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 640
EP 644
DI 10.1038/363640a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900060
PM 8510758
DA 2026-03-10
ER

PT J
AU VIDALE, JE
   HOUSTON, H
AF VIDALE, JE
   HOUSTON, H
TI THE DEPTH DEPENDENCE OF EARTHQUAKE DURATION AND IMPLICATIONS FOR RUPTURE MECHANISMS
SO NATURE
LA English
DT Article
ID subduction-zone earthquakes; deep-focus earthquakes; source parameters; upper-mantle; region; waves
AB THE duration of rupture is a fundamental characteristic of earthquakes, and is important for understanding the mechanics of faulting1,2. The complexity of the seismic source and the incoherence of the high-frequency seismic wavefield often inhibit the identification, location and timing of features in the later part of earthquake rupture. Here we sum many teleseismic records from regional seismic arrays, producing an unusually clear depiction of the earthquake source at short periods by suppressing background noise and coda generated near the receivers. The ending, as well as the beginning, of rupture is clearly identifiable for most earthquakes examined. Measurements of 130 large earthquakes show that near 100 km depth, rupture duration averages 11 s when scaled to a moment of 10(26) dyn cm; this decreases to 5.5 s at 650 km depth. Models of faulting suggest that duration should be inversely proportional to the shear-wave velocity and the cube root of stress drop. Thus, to explain the observed twofold decrease in duration with depth, stress drops would have to increase by a factor of four, as shear velocity increases with depth by only about 20%. However, observed stress drops show no strong trend with depth3,4, suggesting that the faulting process changes with depth.
C1 UNIV CALIF SANTA CRUZ,INST TECTON,EARTH SCI BOARD,SANTA CRUZ,CA 95064.
C3 University of California System; University of California Santa Cruz
RP VIDALE, JE (corresponding author), US GEOL SURVEY,MS 977,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA.
NR 22
TC 59
Z9 66
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 45
EP 47
DI 10.1038/365045a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600049
DA 2026-03-10
ER

PT J
AU KEAVENEY, M
   BERKENSTAM, A
   FEIGENBUTZ, M
   VRIEND, G
   STUNNENBERG, HG
AF KEAVENEY, M
   BERKENSTAM, A
   FEIGENBUTZ, M
   VRIEND, G
   STUNNENBERG, HG
TI RESIDUES IN THE TATA-BINDING PROTEIN REQUIRED TO MEDIATE A TRANSCRIPTIONAL RESPONSE TO RETINOIC ACID IN EC CELLS
SO NATURE
LA English
DT Article
ID activation domain; stem-cells; gene; e1a; coactivators; specificity; promoter; receptor; invivo; yeast
AB THE eukaryotic TATA-binding protein TBP, which is required for transcription by RNA polymerase II, is tightly associated with a particular set of factors in the TFIID complex1-5, and as such provides a target for transcriptional regulation exerted by upstream factors. An embryonic carcinoma (EC) cell-specific activity like that of the viral factor E1A has been implicated in the mediation of transactivation from the retinoic acid receptor to human TBP, but yeast TBP cannot perform this function6. Using TBP mutants with an altered TATA-box-binding specificity7, we show here that yeast TBP can mediate transcriptional activation in mammalian cells and that its inability to convey retinoic acid-dependent transactivation in EC cells is due to specific residues in its core region. These residues preclude a functional association with the cellular E1A-like activity. TBP is thus a target for retinoic acid-dependent transactivation in EC cells by providing a surface for interaction with the EC cell-specific E1A-like activity.
C1 EMBL,GENE EXPRESS PROGRAM,MEYERHOFSTR 1,W-6900 HEIDELBERG,GERMANY.
   EMBL,BIOL STRUCT PROGRAM,W-6900 HEIDELBERG,GERMANY.
C3 European Molecular Biology Laboratory (EMBL); European Molecular Biology Laboratory (EMBL)
NR 31
TC 59
Z9 59
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 562
EP 566
DI 10.1038/365562a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100060
PM 8413615
DA 2026-03-10
ER

PT J
AU AMARI, S
   HOPPE, P
   ZINNER, E
   LEWIS, RS
AF AMARI, S
   HOPPE, P
   ZINNER, E
   LEWIS, RS
TI THE ISOTOPIC COMPOSITIONS AND STELLAR SOURCES OF METEORITIC GRAPHITE GRAINS
SO NATURE
LA English
DT Article
AB The isotopic compositions of interstellar graphite grains in meteorites provide a record of the stellar environments in which they formed.The grains have C-12/C-13 ratios that range far from the terrestrial value, as well as large variations in N-14/N-15 and O-16/O-18, and pronounced Mg-29 excesses from the decay of extinct Al-26. This isotopic variability indicates several types of stellar source, including asymptotic giant branch stars, Wolf-Rayet stars and novae.
C1 UNIV CHICAGO,ENRICO FERMI INST,CHICAGO,IL 60637.
   WASHINGTON UNIV,DEPT PHYS,ST LOUIS,MO 63130.
C3 University of Chicago; Washington University (WUSTL)
RP AMARI, S (corresponding author), WASHINGTON UNIV,MCDONNELL CTR SPACE SCI,ST LOUIS,MO 63130, USA.
NR 20
TC 53
Z9 54
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 806
EP 809
DI 10.1038/365806a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100040
DA 2026-03-10
ER

PT J
AU WOO, R
   GAZIS, P
AF WOO, R
   GAZIS, P
TI LARGE-SCALE SOLAR-WIND STRUCTURE NEAR THE SUN DETECTED BY DOPPLER SCINTILLATION
SO NATURE
LA English
DT Article
AB STUDIES of the solar wind in the inner heliosphere (between the solar-wind source surface at approximately 0.01 AU and 0.3 AU are hampered by the lack of in situ spacecraft measurements. Radio propagation measurements-using both natural1-7 and spacecraft8-14 radio signals-have provided many insights, but information on large-scale solar-wind structure inside 0.3 AU that can be related to coronal features or direct spacecraft measurements at larger distances has nevertheless remained elusive. Here we report the detection of solar-wind structure between 0.08 and 0.53 AU, based on the response of the 13-cm radio signals from the Pioneer Venus Orbiter to electron-density fluctuations and solar-wind speed within this region. These Doppler scintillation measurements were made during the late declining phase of the most recent cycle of solar activity, when the solar wind exhibited recurrent high-speed streams. Near 0.5 AU, we find narrow regions of enhanced scintillation which appear to be associated with compressed plasma at the leading edges of these streams, consistent with previous scintillation measurements15,16. Inside 0.2 AU, however, scintillation enhancements are conspicuously absent from the fast streams, and instead occur in regions where the average solar wind is slow. They exhibit high variability, and appear to be the interplanetary manifestation of coronal mass ejections. The plasma structures giving rise to these enhanced scintillations apparently undergo significant evolution inside 0.3 AU.
C1 NASA, AMES RES CTR, SAN JOSE STATE UNIV FDN, MOFFETT FIELD, CA 94035 USA.
C3 California State University System; San Jose State University; National Aeronautics & Space Administration (NASA); NASA Ames Research Center
RP WOO, R (corresponding author), JET PROP LAB, PASADENA, CA 91109 USA.
NR 41
TC 22
Z9 22
U1 0
U2 2
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 543
EP 545
DI 10.1038/366543a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800062
DA 2026-03-10
ER

PT J
AU CHOY, B
   GREEN, MR
AF CHOY, B
   GREEN, MR
TI EUKARYOTIC ACTIVATORS FUNCTION DURING MULTIPLE STEPS OF PREINITIATION COMPLEX ASSEMBLY
SO NATURE
LA English
DT Article
ID rna polymerase-ii; transcription factor atf; tata-binding-protein; gal4 derivatives; tfiid complex; invitro; mechanism; dna; domain; promoters
AB Eukaryotic activator proteins (activators) stimulate transcription by increasing assembly of the preinitiation complex. We have developed methods to quantify the stable assembly of general transcription factors into transcriptional complexes in response to activators. We show that activators function during at least two stages of preinitiation complex assembly: first, to recruit the general transcription factor TFIIB, and then at a second step, after TFIIB entry. It is at this second step that the TATA-box binding protein associated factors act. This step also seems to be critical for activators to stimulate transcription synergistically.
RP CHOY, B (corresponding author), UNIV MASSACHUSETTS,MED CTR,PROGRAM MOLEC MED,373 PLANTAT ST,WORCESTER,MA 01605, USA.
NR 50
TC 266
Z9 288
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 531
EP 536
DI 10.1038/366531a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800060
PM 8255291
DA 2026-03-10
ER

PT J
AU ROY, AL
   MALIK, S
   MEISTERERNST, M
   ROEDER, RG
AF ROY, AL
   MALIK, S
   MEISTERERNST, M
   ROEDER, RG
TI AN ALTERNATIVE PATHWAY FOR TRANSCRIPTION INITIATION INVOLVING TFII-I
SO NATURE
LA English
DT Article
ID rna polymerase-ii; tata-binding protein; gene-transcription; complex; activation; promoter
AB THE minimal promoter elements required for initiation by RNA polymerase II include the TATA box and/or an initiator element (Inr) at or near the transcription start site1-4. Studies of the adeno-virus major late core promoter (containing both elements) have demonstrated an initiation pathway that involves binding of the transcription factor TFIID (or the derived subunit, the TATA-binding protein TBP (TFIIDtau)) to the TATA element, which is facilitated by transcription factor TFIIA, followed by sequential interactions of other general factors4-8. Here we describe a novel pathway that requires an intact Inr and the Inr-binding factor TFII-I (ref. 3). Sequential addition of the general factors generated TFII-I-dependent preinitiation complexes different from those formed with TFIIA. Furthermore, TBP bound cooperatively (with only TFII-I) to an Inr-containing TATA-less promoter, suggesting a means for activation of TATA-less promoters, which nonetheless require TFIID (refs 9-11). These observations provide support for functionally distinct pathways which could be subject to differential regulation by specific activators or repressors.
RP ROY, AL (corresponding author), ROCKEFELLER UNIV,BIOCHEM & MOLEC BIOL LAB,1230 YORK AVE,NEW YORK,NY 10021, USA.
NR 20
TC 153
Z9 165
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 355
EP 359
DI 10.1038/365355a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600057
PM 8377828
DA 2026-03-10
ER

PT J
AU KURAHASHI, T
   YAU, KW
AF KURAHASHI, T
   YAU, KW
TI COEXISTENCE OF CATIONIC AND CHLORIDE COMPONENTS IN ODORANT-INDUCED CURRENT OF VERTEBRATE OLFACTORY RECEPTOR-CELLS
SO NATURE
LA English
DT Article
ID cyclic-nucleotides; adenylate-cyclase; gated channels; neurons; cilia; activation; membrane; conductance; newt; transduction
AB ODORANT stimulation leads to a depolarization of olfactory receptor neurons1-3. A mechanism underlying this transduction, which occurs in the sensory cilia3-6, involves a G-protein-mediated increase in adenylyl cyclase activity7-10, and therefore a rise in internal cyclic AMP and consequent opening of a cAMP-gated cation channel on the plasma membrane11-22. Another mechanism, not as well established, involves the opening of an inositol trisphosphate-activated cation channel on the plasma membrane23 as a result of phospholipase C activity24,25. In both cases, an influx of cations is thought to generate the depolarizing receptor potential. We now report, however, that the mechanism is actually more complex. The odorant-induced current appears to contain an inward chloride component also, which is triggered by calcium influx through the cation-selective channel. This newly found chloride component can be as large as the cationic component. The co-existence of cationic and chloride components in the odorant response, possibly unique among sensory transduction mechanisms, may serve to reduce variations in the transduction current resulting from changes in external ionic concentrations around the olfactory cilia. Our finding can explain the long-standing puzzle of why removal of most mucosal cations still does not diminish the amplitude of the olfactory receptor cell response26-28.
C1 JOHNS HOPKINS UNIV,SCH MED,HOWARD HUGHES MED INST,BALTIMORE,MD 21205.
   JOHNS HOPKINS UNIV,SCH MED,DEPT NEUROSCI,BALTIMORE,MD 21205.
C3 Johns Hopkins University; Howard Hughes Medical Institute; Johns Hopkins University
NR 33
TC 277
Z9 300
U1 2
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 71
EP 74
DI 10.1038/363071a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200061
PM 7683113
DA 2026-03-10
ER

PT J
AU IVINSON, AJ
AF IVINSON, AJ
TI INHIBITION AND OVER-REACTION
SO NATURE
LA English
DT Article
NR 5
TC 1
Z9 1
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 488
EP 488
DI 10.1038/366488a0
PG 1
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800071
DA 2026-03-10
ER

PT J
AU NAMBA, T
   SUGIMOTO, Y
   NEGISHI, M
   IRIE, A
   USHIKUBI, F
   KAKIZUKA, A
   ITO, S
   ICHIKAWA, A
   NARUMIYA, S
AF NAMBA, T
   SUGIMOTO, Y
   NEGISHI, M
   IRIE, A
   USHIKUBI, F
   KAKIZUKA, A
   ITO, S
   ICHIKAWA, A
   NARUMIYA, S
TI ALTERNATIVE SPLICING OF C-TERMINAL TAIL OF PROSTAGLANDIN-E RECEPTOR SUBTYPE-EP3 DETERMINES G-PROTEIN SPECIFICITY
SO NATURE
LA English
DT Article
ID human beta-2-adrenergic receptor; bovine adrenal-medulla; pertussis toxin; thromboxane-a2 receptor; signal transduction; adenylyl cyclase; expression; cloning; regions; cdna
AB PEPTIDE hormones, neurotransmitters, and autacoids activate a family of seven-transmembrane-domain receptors1. Each of these receptors specifically couples to one of several G proteins, G(s), G(i), G(o) and G(p), to activate a specific second messenger system2. Cell surface receptors for prostanoids have been characterized pharmacologically3 and the complementary DNAs for thromboxane A2 receptor4,5 and the EP3 subtype of the prostaglandin (PG)E receptor6 reveal that they belong to the seven-transmembrane-domain receptor family. The EP3 receptor mediates the diverse physiological actions of PGE2 (ref. 3). Although most of them occur through coupling of the EP3 receptor to G(i) and inhibition of adenylyl cyclase, the EP3-mediated contraction of uterine muscle can only occur by activation of another second messenger pathway7. In chromaffin cells, two different second messenger pathways are activated by PGE2 binding to an apparently single EP3 receptor class8. Here we show that at least four isoforms of the EP3 receptor, which differ only at their C-terminal tails and are produced by alternative splicing, couple to different G proteins to activate different second messenger systems.
C1 KYOTO UNIV,FAC MED,DEPT PHARMACOL,SAKYO KU,KYOTO 606,JAPAN.
   KYOTO UNIV,FAC MED,DEPT ANAESTHESIA,SAKYO KU,KYOTO 606,JAPAN.
   KYOTO UNIV,FAC PHARMACEUT SCI,DEPT PHYSIOL CHEM,SAKYO KU,KYOTO 606,JAPAN.
   OSAKA BIOSCI INST,SUITA,OSAKA 565,JAPAN.
C3 Kyoto University; Kyoto University; Kyoto University
NR 30
TC 541
Z9 591
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 166
EP 170
DI 10.1038/365166a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200050
PM 8396726
DA 2026-03-10
ER

PT J
AU FUNAHASHI, S
   CHAFEE, MV
   GOLDMANRAKIC, PS
AF FUNAHASHI, S
   CHAFEE, MV
   GOLDMANRAKIC, PS
TI PREFRONTAL NEURONAL-ACTIVITY IN RHESUS-MONKEYS PERFORMING A DELAYED ANTI-SACCADE TASK
SO NATURE
LA English
DT Article
ID posterior parietal cortex; superior colliculus; eye-movements; frontal-lobe; projections; responses; macaque; areas; goal
AB PATIENTS with damage to the dorsolateral prefrontal cortex are impaired on cognitive tasks such as the Wisconsin Card Sort Test1, the Stroop Test2 and an anti-saccade paradigm3, in which sensory-guided habitual responses must be suppressed in favour of conceptually or memory-guided responses. We report here recordings from prefrontal neurons in rhesus monkeys trained to perform a delayed anti-saccade task based on tests that have been used with humans3. Activity in the same prefrontal neurons was recorded across conditions when saccades were made toward a remembered target, and also when this prepotent response was suppressed and a saccade in the opposite direction required. Our findings show that most prefrontal neurons code the location of the visual stimulus in working memory, and that this memory can be engaged to suppress as well as prescribe a response. These results establish, in a subset of prefrontal neurons, the iconic nature of the memory code, and suggest a role for visual memory in response suppression.
C1 YALE UNIV,SCH MED,NEUROBIOL SECT,NEW HAVEN,CT 06510.
C3 Yale University
NR 23
TC 548
Z9 642
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 753
EP 756
DI 10.1038/365753a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200063
PM 8413653
DA 2026-03-10
ER

PT J
AU AUBOURG, E
   BAREYRE, P
   BREHIN, S
   GROS, M
   LACHIEZEREY, M
   LAURENT, B
   LESQUOY, E
   MAGNEVILLE, C
   MILSZTAJN, A
   MOSCOSO, L
   QUEINNEC, F
   RICH, J
   SPIRO, M
   VIGROUX, L
   ZYLBERAJCH, S
   ANSARI, R
   CAVALIER, F
   MONIEZ, M
   BEAULIEU, JP
   FERLET, R
   GRISON, P
   VIDALMADJAR, A
   GUIBERT, J
   MOREAU, O
   TAJAHMADY, F
   MAURICE, E
   PREVOT, L
   GRY, C
AF AUBOURG, E
   BAREYRE, P
   BREHIN, S
   GROS, M
   LACHIEZEREY, M
   LAURENT, B
   LESQUOY, E
   MAGNEVILLE, C
   MILSZTAJN, A
   MOSCOSO, L
   QUEINNEC, F
   RICH, J
   SPIRO, M
   VIGROUX, L
   ZYLBERAJCH, S
   ANSARI, R
   CAVALIER, F
   MONIEZ, M
   BEAULIEU, JP
   FERLET, R
   GRISON, P
   VIDALMADJAR, A
   GUIBERT, J
   MOREAU, O
   TAJAHMADY, F
   MAURICE, E
   PREVOT, L
   GRY, C
TI EVIDENCE FOR GRAVITATIONAL MICROLENSING BY DARK OBJECTS IN THE GALACTIC HALO
SO NATURE
LA English
DT Article
ID matter
AB THE flat rotation curves of spiral galaxies, including our own, indicate that they are surrounded by unseen haloes of 'dark matter'1,2. In the absence of a massive halo, stars and gas in the outer portions of a galaxy would orbit the centre more slowly, just as the outer planets in the Solar System circle the Sun more slowly than the inner ones. So far, however, there has been no direct observational evidence for the dark matter, or its characteristics. Paczynski3 suggested that dark bodies in the halo of our Galaxy can be detected when they act as gravitational 'microlenses', amplifying the light from stars in nearby galaxies. The duration of such an event depends on the mass, distance and velocity of the dark object. We have been monitoring the brightness of three million stars in the Large Magellanic Cloud for over three years, and here report the detection of two possible microlensing events. The brightening of the stars was symmetrical in time, achromatic and not repeated during the monitoring period. The timescales of the two events are about thirty days and imply that the masses of the lensing objects lie between a few hundredths and one solar mass. The number of events observed is consistent with the number expected if the halo is dominated by objects with masses in this range.
C1 CTR ORSAY,ACCELERATEUR LINEAIRE LAB,F-91405 ORSAY,FRANCE.
   INST ASTROPHYS,F-75014 PARIS,FRANCE.
   OBSERV PARIS,INST NATL SCI UNIVERS,CTR ANALYSE IMAGES,F-75014 PARIS,FRANCE.
   OBSERV MARSEILLE,F-13248 MARSEILLE 04,FRANCE.
   LAB ASTRON SPATIALE MARSEILLE,F-13120 MARSEILLE,FRANCE.
C3 Sorbonne Universite; Universite PSL; Observatoire de Paris; Aix-Marseille Universite
RP AUBOURG, E (corresponding author), CTR ETUD SACLAY,DAPNIA,F-91191 GIF SUR YVETTE,FRANCE.
NR 8
TC 696
Z9 717
U1 0
U2 16
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 623
EP 625
DI 10.1038/365623a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600050
DA 2026-03-10
ER

PT J
AU LOHOF, AM
   IP, NY
   POO, MM
AF LOHOF, AM
   IP, NY
   POO, MM
TI POTENTIATION OF DEVELOPING NEUROMUSCULAR SYNAPSES BY THE NEUROTROPHINS NT-3 AND BDNF
SO NATURE
LA English
DT Article
ID nerve growth-factor; neurons; expression; ngf; receptor; culture; induction; patterns; invitro
AB THE neurotrophins are a family of neurotrophic factors that promote survival and differentiation of various neuronal populations1,2. Although the long-term effects of neurotrophins on neuronal survival and differentiation have been intensively studied, nothing is known about their effects on synaptic function. Here we report that acute exposure to neurotrophin-3 (NT-3)3,4 or brain-derived neurotrophic factor (BDNF)5, but not nerve growth factor (NGF)6, rapidly potentiates the spontaneous and impulse-evoked synaptic activity of developing neuromuscular synapses in culture. The effect appears to be presynaptic in origin and to be mediated by the Trk family of receptor tyrosine kinases7. These results provide evidence for the regulation of the function of developing synapses by neurotrophins.
C1 COLUMBIA UNIV,DEPT BIOL SCI,NEW YORK,NY 10027.
   REGENERON PHARMACEUT INC,TARRYTOWN,NY 10591.
C3 Columbia University; Regeneron
NR 35
TC 705
Z9 778
U1 1
U2 26
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 350
EP 353
DI 10.1038/363350a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700053
PM 8497318
DA 2026-03-10
ER

PT J
AU CANESSA, CM
   HORISBERGER, JD
   ROSSIER, BC
AF CANESSA, CM
   HORISBERGER, JD
   ROSSIER, BC
TI EPITHELIAL SODIUM-CHANNEL RELATED TO PROTEINS INVOLVED IN NEURODEGENERATION
SO NATURE
LA English
DT Article
ID ion channel; caenorhabditis-elegans; hair cell; currents; chick
AB THE epithelial amiloride-sensitive sodium channel constitutes the rate limiting step for sodium reabsorbtion by the epithelia lining the distal part of the kidney tubule, the urinary bladder and the distal colon. Reabsorbtion of sodium through this channel, which is regulated by hormones such as aldosterone and vasopressin, is one of the essential mechanisms involved in the regulation of sodium balance, blood volume and blood pressure1-6. Here we isolate a DNA from epithelial cells of rat distal colon and identify it by functional expression of an amiloride-sensitive sodium current in Xenopus oocyte. The deduced polypeptide (698 amino acids) has at least two putative transmembrane segments. Expression of this protein in Xenopus oocytes reconstitutes the functional properties of the highly selective amiloride-sensitive, epithelial sodium channel. The gene encoding this rat sodium channel subunit shares significant sequence similarity with mec-4 and deg-1, members of a family of Caenorhabditis elegans genes involved in sensory touch transduction and, when mutated, neuronal degeneration. We propose that the gene products of these three genes are members of a gene family coding for cation channels.
C1 UNIV LAUSANNE,INST PHARMACOL & TOXICOL,RUE BUGNON 27,CH-1005 LAUSANNE,SWITZERLAND.
C3 University of Lausanne
NR 22
TC 854
Z9 916
U1 0
U2 18
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 467
EP 470
DI 10.1038/361467a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300066
PM 8381523
DA 2026-03-10
ER

PT J
AU HOLTON, TA
   BRUGLIERA, F
   LESTER, DR
   TANAKA, Y
   HYLAND, CD
   MENTING, JGT
   LU, CY
   FARCY, E
   STEVENSON, TW
   CORNISH, EC
AF HOLTON, TA
   BRUGLIERA, F
   LESTER, DR
   TANAKA, Y
   HYLAND, CD
   MENTING, JGT
   LU, CY
   FARCY, E
   STEVENSON, TW
   CORNISH, EC
TI CLONING AND EXPRESSION OF CYTOCHROME-P450 GENES-CONTROLLING FLOWER COLOR
SO NATURE
LA English
DT Article
ID saccharomyces-cerevisiae; flavonoids; hybrida
AB BLUE and violet flowers generally contain derivatives of delphinidin; red and pink flowers generally contain derivatives of cyanidin or pelargonidin1. Differences in hydroxylation patterns of these three major classes of anthocyanidins are controlled by the cytochrome P450 enzymes flavonoid 3'-hydroxylase and flavonoid 3',5'-hydroxylase. Here we report on the isolation of complementary DNA clones of two different flavonoid 3',5'-hydroxylase genes that are expressed in petunia flowers. Restriction-fragment length polymorphism mapping and complementation of mutant petunia lines showed that the flavonoid 3',5'-hydroxylase genes correspond to the genetic loci Hf1 and Hf2.
C1 SUNTORY LTD,SHIMAMOTO,OSAKA 618,JAPAN.
   INRA,GENET & AMELIORAT PLANTES STN,F-21034 DIJON,FRANCE.
C3 Suntory Holdings Ltd; INRAE
RP HOLTON, TA (corresponding author), CALGENE PACIFIC PTY LTD,16 GIPPS ST,COLLINGWOOD,VIC 3066,AUSTRALIA.
NR 21
TC 280
Z9 363
U1 6
U2 99
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 276
EP 279
DI 10.1038/366276a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500067
PM 8232589
DA 2026-03-10
ER

PT J
AU WATLING, D
   GUSCHIN, D
   MULLER, M
   SILVENNOINEN, O
   WITTHUHN, BA
   QUELLE, FW
   ROGERS, NC
   SCHINDLER, C
   STARK, GR
   IHLE, JN
   KERR, IM
AF WATLING, D
   GUSCHIN, D
   MULLER, M
   SILVENNOINEN, O
   WITTHUHN, BA
   QUELLE, FW
   ROGERS, NC
   SCHINDLER, C
   STARK, GR
   IHLE, JN
   KERR, IM
TI COMPLEMENTATION BY THE PROTEIN-TYROSINE KINASE JAK2 OF A MUTANT-CELL LINE DEFECTIVE IN THE INTERFERON-GAMMA SIGNAL-TRANSDUCTION PATHWAY
SO NATURE
LA English
DT Article
ID ifn-gamma; phosphorylation; transcription; activation; receptor; antigen; domain
AB INTERFERONS (IFNs) alpha/beta (type I) and gamma (type II) bind to distinct cell surface receptors1, inducing transcription of overlapping sets of genes by intracellular pathways that have recently attracted much attention2,3. Previous studies using cell lines selected for their inability to respond to IFN-alpha (ref. 4) have shown that the protein kinase Tyk2 plays a central role in the IFN alpha/beta response5. Here we report the isolation of the cell line gamma1A, selected for its inability to express IFN-gamma-inducible cell-surface markers, that is deficient in all aspects of the IFN-gamma response tested, but responds normally to IFNs alpha and beta. The mutant cells can be complemented by the expression of another member of the JAK family of protein tyrosine kinases, JAK2 (refs 6-9). Unlike IFNs alpha and beta, IFN-gamma induces rapid tyrosine phosphorylation of JAK2 in wild-type cells, and JAK2 immunoprecipitates from these cells show tyrosine kinase activity. These responses are absent in gamma1A cells. JAK2 is therefore required for the response to IFN-gamma but not to IFNs alpha and beta.
C1 NYU MED CTR, DEPT PHARMACOL, NEW YORK, NY 10016 USA.
   ST JUDE CHILDRENS RES HOSP, DEPT BIOCHEM, MEMPHIS, TN 38101 USA.
   COLUMBIA UNIV, MED CTR, DEPT MOLEC MED, NEW YORK, NY 10032 USA.
   CLEVELAND CLIN FDN, RES INST, DEPT MOLEC BIOL, CLEVELAND, OH 44195 USA.
C3 New York University; St Jude Children's Research Hospital; Columbia University; Cleveland Clinic Foundation
RP WATLING, D (corresponding author), IMPERIAL CANC RES FUND, 44 LINCOLNS INN FIELDS, LONDON WC2A 3PX, ENGLAND.
NR 27
TC 479
Z9 516
U1 0
U2 4
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 166
EP 170
DI 10.1038/366166a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600060
PM 7901766
DA 2026-03-10
ER

PT J
AU UMEZAWA, A
   ZHANG, W
   GUREVICH, A
   FENG, Y
   HELLSTROM, EE
   LARBALESTIER, DC
AF UMEZAWA, A
   ZHANG, W
   GUREVICH, A
   FENG, Y
   HELLSTROM, EE
   LARBALESTIER, DC
TI FLUX-PINNING, GRANULARITY AND THE IRREVERSIBILITY LINE OF THE HIGH-T(C) SUPERCONDUCTOR HGBA2CUO4+X
SO NATURE
LA English
DT Article
ID currents
AB THE recent discoveries of superconductivity at 94 K in the single-CuO2-layer compound HgBa2CuO4+x (Hg-1201)1 and at 133 K in its two- and three-copper-layer analogues 2(Hg-1212 and Hg-1223) have renewed interest in the search for new high-transition-temperature (high-T(c)) superconductors. But whatever the T(c), high values of intergrain critical current density are required for large-scale applications; thus, the material must have good electromagnetic connectivity between grains (it must not be electromagnetically granular) and it should be able to maintain its current-carrying capacity in high magnetic fields (it should have a high irreversibility field, H*(T)). Putilin et al.1 surmised that the small CuO2 layer spacing of Hg-1201 might yield a high H*(T). We report here that H*(T) is indeed significantly higher than for the two- and three-copper-layer Bi-Sr-Ca-Cu-O compounds (Bi-2212 and Bi-2223), but lower than for YBa2Cu3O7 (Y-123). The low-temperature flux pinning is also strong. Like Y-123, however, Hg-1201 is electromagnetically granular. A high degree of grain alignment will probably be necessary to remove this granularity; by analogy with the bismuth compounds, this is likely to be easier if the two-mercury-layer counterparts of Bi-22XY (Hg-2201, -2212 or -2223) can be synthesized.
C1 UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706.
C3 University of Wisconsin System; University of Wisconsin Madison
RP UMEZAWA, A (corresponding author), UNIV WISCONSIN,DEPT MAT SCI & ENGN,APPL SUPERCOND CTR,MADISON,WI 53706, USA.
NR 10
TC 64
Z9 64
U1 0
U2 73
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 129
EP 131
DI 10.1038/364129a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700042
DA 2026-03-10
ER

PT J
AU QIAN, XQ
   JEON, CJ
   YOON, HS
   AGARWAL, K
   WEISS, MA
AF QIAN, XQ
   JEON, CJ
   YOON, HS
   AGARWAL, K
   WEISS, MA
TI STRUCTURE OF A NEW NUCLEIC-ACID-BINDING MOTIF IN EUKARYOTIC TRANSCRIPTIONAL ELONGATION-FACTOR TFIIS
SO NATURE
LA English
DT Article
ID rna polymerase-ii; zinc finger; crystal-structure; glucocorticoid receptor; dna recognition; domains; protein; complex; subunit; block
AB TRANSCRIPTIONAL elongation involves dynamic interactions among RNA polymerase and single-stranded and double-stranded nucleic acids in the ternary complex1-4. In prokaryotes its regulation provides an important mechanism of genetic control1. Analogous eukaryotic mechanisms are not well understood5, but may control expression of proto-oncogenes6,7 and viruses, including the human immunodeficiency virus HIV-1 (ref. 8). The highly conserved eukaryotic transcriptional elongation factor TFIIS9 enables RNA polymerase II (RNAPII) to read though pause or termination sites, nucleosomes and sequence-specific DNA-binding proteins10-14                . Two distinct domains of human TFIIS, which bind RNAPII and nucleic acids, regulate read-through10 and possibly nascent transcript cleavage11-15. Here we describe the three-dimensional NMR16 structure of a Cys4 nucleic-acid-binding domain from human TFIIS9,10. Unlike previously characterized zinc modules17-21, which contain an alpha-helix, this structure consists of a three-stranded beta-sheet. Analogous Cys4, structural motifs may occur in other proteins involved in DNA or RNA transactions22-24, including RNAPII itself25. This new structure, designated the Zn ribbon, extends the repertoire of Zn-mediated peptide architectures26 and highlights the growing recognition of the beta-sheet as a motif of nucleic-acid recognition27,28.
C1 UNIV CHICAGO,DEPT BIOCHEM & MOLEC BIOL,CHICAGO,IL 60637.
   UNIV CHICAGO,DEPT CHEM,CHICAGO,IL 60637.
   MASSACHUSETTS GEN HOSP,DEPT MED,BOSTON,MA 02114.
C3 University of Chicago; University of Chicago; Harvard University; Harvard University Medical Affiliates; Massachusetts General Hospital
RP QIAN, XQ (corresponding author), HARVARD UNIV,SCH MED,DEPT BIOL CHEM & MOLEC PHARMACOL,BOSTON,MA 02115, USA.
NR 30
TC 114
Z9 129
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 277
EP 279
DI 10.1038/365277a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100062
PM 7626141
DA 2026-03-10
ER

PT J
AU PAPA, FR
   HOCHSTRASSER, M
AF PAPA, FR
   HOCHSTRASSER, M
TI THE YEAST DOA4 GENE ENCODES A DEUBIQUITINATING ENZYME RELATED TO A PRODUCT OF THE HUMAN TRE-2 ONCOGENE
SO NATURE
LA English
DT Article
ID n-end rule; ubiquitin-conjugating enzyme; saccharomyces-cerevisiae; transcriptional regulator; functional-analysis; protein; invivo; cells; transformation; degradation
AB Modification of specific intracellular proteins by ubiquitin targets them for degradation. We describe a yeast enzyme, Doa4, that is integral to the degradation of ubiquitinated proteins and is required in diverse physiological processes. Doa4 appears to function late in the proteolytic pathway by cleaving ubiquitin from substrate remnants still bound to protease. The human tre-2 oncogene encodes a deubiquitinating enzyme similar to Doa4, indicating a role for the ubiquitin system in mammalian growth control.
RP PAPA, FR (corresponding author), UNIV CHICAGO,DEPT BIOCHEM & MOLEC BIOL,920 E 58TH ST,CHICAGO,IL 60637, USA.
NR 45
TC 349
Z9 382
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 313
EP 319
DI 10.1038/366313a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500039
PM 8247125
DA 2026-03-10
ER

PT J
AU GALIONE, A
   WHITE, A
   WILLMOTT, N
   TURNER, M
   POTTER, BVL
   WATSON, SP
AF GALIONE, A
   WHITE, A
   WILLMOTT, N
   TURNER, M
   POTTER, BVL
   WATSON, SP
TI CGMP MOBILIZES INTRACELLULAR CA2+ IN SEA-URCHIN EGGS BY STIMULATING CYCLIC ADP-RIBOSE SYNTHESIS
SO NATURE
LA English
DT Article
ID dependent protein-kinase; calcium; activation; release; enzyme
AB MANY hormones or neurotransmitters act at cell surface receptors to increase the intracellular free calcium concentration, triggering a wide range of cellular responses1. As the source of this Ca2+ is often internal stores, additional messengers are required to convey the hormonal message from the plasma membrane. Cyclic ADP-ribose (cADPR) has been proposed as the endogenous activator of Ca2+-induced Ca2+ release by the ryanodine receptor in sea urchin eggs and in several mammalian cell types2-8,22. A second messenger role for cADPR requires that its intracellular levels be under the control of extracellular stimuli. Here we demonstrate a novel action of 3',5'-cyclic guanosine monophosphate (cGMP) in stimulating the synthesis of cADPR from beta-NAD+ by activating its synthetic enzyme ADP-ribosyl cyclase9-11 in sea urchin eggs and egg homogenates. We suggest that cADPR may transduce signals generated by cell surface receptors or gaseous transmitters linked to cGMP production.
C1 UNIV BATH,SCH PHARM & PHARMACOL,BATH BA2 7AY,AVON,ENGLAND.
   UNIV BATH,INST LIFE SCI,BATH BA2 7AY,AVON,ENGLAND.
C3 University of Bath; University of Bath
RP GALIONE, A (corresponding author), UNIV OXFORD,DEPT PHARMACOL,MANSFIELD RD,OXFORD OX1 3QT,ENGLAND.
NR 22
TC 273
Z9 285
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 456
EP 459
DI 10.1038/365456a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300061
PM 7692303
DA 2026-03-10
ER

PT J
AU DOUGLASS, JK
   WILKENS, L
   PANTAZELOU, E
   MOSS, F
AF DOUGLASS, JK
   WILKENS, L
   PANTAZELOU, E
   MOSS, F
TI NOISE ENHANCEMENT OF INFORMATION-TRANSFER IN CRAYFISH MECHANORECEPTORS BY STOCHASTIC RESONANCE
SO NATURE
LA English
DT Article
ID bistable systems; phase locking; dynamics; neurons; population
AB IN linear information theory, electrical engineering and neurobiology, random noise has traditionally been viewed as a detriment to information transmission. Stochastic resonance (SR) is a nonlinear, statistical dynamics whereby information flow in a multistate system is enhanced by the presence of optimized, random noise1-4. A major consequence of SR for signal reception is that it makes possible substantial improvements in the detection of weak periodic signals. Although SR has recently been demonstrated in several artificial physical systems5,6, it may also occur naturally, and an intriguing possibility is that biological systems have evolved the capability to exploit SR by optimizing endogenous sources of noise. Sensory systems are an obvious place to look for SR, as they excel at detecting weak signals in a noisy environment. Here we demonstrate SR using external noise applied to crayfish mechanoreceptor cells. Our results show that individual neurons can provide a physiological substrate for SR in sensory systems.
C1 UNIV MISSOURI, DEPT BIOL, ST LOUIS, MO 63121 USA.
   UNIV MISSOURI, DEPT PHYS, ST LOUIS, MO 63121 USA.
C3 University of Missouri System; University of Missouri Saint Louis; University of Missouri System; University of Missouri Saint Louis
NR 29
TC 1303
Z9 1408
U1 0
U2 122
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 337
EP 340
DI 10.1038/365337a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600051
PM 8377824
DA 2026-03-10
ER

PT J
AU BONYHADI, ML
   RABIN, L
   SALIMI, S
   BROWN, DA
   KOSEK, J
   MCCUNE, JM
   KANESHIMA, H
AF BONYHADI, ML
   RABIN, L
   SALIMI, S
   BROWN, DA
   KOSEK, J
   MCCUNE, JM
   KANESHIMA, H
TI HIV INDUCES THYMUS DEPLETION INVIVO
SO NATURE
LA English
DT Article
ID scid-hu mouse; human immunodeficiency virus; t-cells; infection; apoptosis; differentiation; model; death
AB HUMAN immunodeficiency virus (HIV) disease is typified by declining CD4+ T lymphocyte counts in the peripheral circulation, a loss which may be secondary to accelerated destruction, to suppressed differentiation, and/or to sequestration of circulating cells into tissue spaces. As it is hard to distinguish between these possibilities in human subjects, the pathogenic mechanisms associated with HIV infection are unclear. In particular, little is known about the events that occur within infected lymphoid organs in which most CD4 T lymphocytes mature and function1,2. To obtain a better description of HIV pathogenesis in vivo, we have implanted human haematolymphoid organs into the immunodeficient SCID mouse to create the SCID-hu mouse3,4. We have previously shown that these organ systems promote long-term multilineage human haematopoiesis and are permissive for infection with HIV5,6. Here we report that human thymopoiesis is suppressed by HIV infection, thereby precluding regeneration of the peripheral T-cell compartment.
C1 VET ADM MED CTR, PALO ALTO, CA 94304 USA.
C3 US Department of Veterans Affairs; Veterans Health Administration (VHA)
RP BONYHADI, ML (corresponding author), SYSTEMIX INC, DIV NEW ENTERPRISE RES, 3155 PORTER DR, PALO ALTO, CA 94304 USA.
NR 31
TC 366
Z9 384
U1 0
U2 3
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 728
EP 732
DI 10.1038/363728a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900058
PM 8100043
DA 2026-03-10
ER

PT J
AU WILSON, GF
   KACZMAREK, LK
AF WILSON, GF
   KACZMAREK, LK
TI MODE-SWITCHING OF A VOLTAGE-GATED CATION CHANNEL IS MEDIATED BY A PROTEIN KINASE-A REGULATED TYROSINE PHOSPHATASE
SO NATURE
LA English
DT Article
ID nicotinic acetylcholine-receptor; bag cell neurons; ion channels; abdominal-ganglion; aplysia; phosphorylation; expression; afterdischarge; modulation; cd45
AB Tyrosine kinases and tyrosine phosphatases are abundant in central nervous system tissue, yet the role of these enzymes in the modulation of neuronal excitability is unknown. Patch-clamp studies of an Aplysia voltage-gated cation channel now demonstrate that a tyrosine phosphatase endogenous to excised patches determines both the gating mode of the channel and the response of the channel to protein kinase A. Moreover, a switch in gating modes similar to that triggered by the phosphatase occurs at the onset of a prolonged change in the excitability of Aplysia bag cell neurons.
C1 YALE UNIV,DEPT PHARMACOL,NEW HAVEN,CT 06510.
C3 Yale University
NR 40
TC 112
Z9 123
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 433
EP 438
DI 10.1038/366433a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800054
PM 8247151
DA 2026-03-10
ER

PT J
AU GRIFFITH, CA
AF GRIFFITH, CA
TI EVIDENCE FOR SURFACE HETEROGENEITY ON TITAN
SO NATURE
LA English
DT Article
ID voyager-1 radio-occultation; infrared observations; atmosphere; aerosols; ocean; model
AB UNLIKE all other planetary satellites, Saturn's moon Titan has a massive atmosphere1-8. At visible wavelengths, a thick stratospheric haze hides the surface from view. The emission from Titan in the infrared is largely from methane, nitrogen and hydrogen also in the stratosphere4. In the near-infrared, however, the extinction from haze decreases, and narrow windows exist in which the atmosphere absorbs only weakly9-14, and through which we might therefore catch a glimpse of the surface. Within two of these windows, Lemmon et al.15,16 recently observed a difference in Titan's albedo when the satellite was at eastern and western elongation with respect to Saturn. Although these observations could be taken to imply that Titan's surface is heterogeneous (and therefore is not covered by a global methane-ethane ocean as predicted previously7), they could also be explained by transient clouds. Here I present observations from two more rotational periods which record the same albedo difference, indicating that the heterogeneity is most unlikely to be associated with transient features and must be intrinsic to the surface. These results also imply that Titan is locked in a synchronous orbit about Saturn.
RP GRIFFITH, CA (corresponding author), NASA,AMES RES CTR,MS 245-3,MOFFETT FIELD,CA 94035, USA.
NR 29
TC 71
Z9 73
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 511
EP 514
DI 10.1038/364511a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700047
DA 2026-03-10
ER

PT J
AU KIM, JL
   NIKOLOV, DB
   BURLEY, SK
AF KIM, JL
   NIKOLOV, DB
   BURLEY, SK
TI CO-CRYSTAL STRUCTURE OF TBP RECOGNIZING THE MINOR-GROOVE OF A TATA ELEMENT
SO NATURE
LA English
DT Article
ID rna polymerase-ii; nucleic-acid interaction; binding-protein; transcription factor; tfiid binds; dna; yeast; complex; box; initiation
AB The three-dimensional structure of a TATA-box binding polypeptide complexed with the TATA element of the adenovirus major late promoter ha's been determined by X-ray crystallography at 2.25 angstrom resolution. Binding of the saddle-shaped protein induces a conformational change in the DNA, inducing sharp kinks at either end of the sequence TATAAAAG. Between the kinks, the right-handed double helix is smoothly curved and partially unwound, presenting a widened minor groove to TBP's concave, antiparallel beta-sheet. Side-chain/base interactions are restricted to the minor groove, and include hydrogen bonds, van der Waals contacts and phenylalanine-base stacking interactions.
C1 ROCKEFELLER UNIV, MOLEC BIOPHYS LABS, 1230 YORK AVE, NEW YORK, NY 10021 USA.
C3 Rockefeller University
NR 56
TC 1042
Z9 1164
U1 0
U2 61
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 520
EP 527
DI 10.1038/365520a0
PG 8
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100045
PM 8413605
DA 2026-03-10
ER

PT J
AU ROY, BA
AF ROY, BA
TI FLORAL MIMICRY BY A PLANT PATHOGEN
SO NATURE
LA English
DT Article
ID anther-smut infection; ustilago-violacea; reproduction; pollinators; vectors
AB INSECTS can effect sexual reproduction in some plant pathogens, such as the rust fungi, by carrying spermatia (gametes) between different mating types1-5. This function of insects is analogous to their role as pollinators of plants, and contrasts with their more widely known5-9 role as vectors of plant pathogens' infectious spores. Here I report an extraordinary case of pathogen-mediated floral mimicry that contributes to fungal reproduction. The rust fungus Puccinia monoica inhibits flowering in its host plants (Arabis species) and radically transforms host morphology, creating elevated clusters of infected leaves that mimic true flowers of unrelated species in shape, size, colour and nectar production. These fungal pseudoflowers attract insects which fertilize the rust. Because the pseudoflowers are highly successful in attracting pollinating insects, they may also affect the reproductive success of nearby flowering plants.
C1 RANCHO SANTA ANA BOT GARDEN,CLAREMONT,CA 91711.
   ROCKY MT BIOL LABS,GOTHIC,CO 81224.
RP ROY, BA (corresponding author), UNIV CALIF DAVIS,DEPT BOT,DAVIS,CA 95616, USA.
NR 30
TC 130
Z9 139
U1 0
U2 68
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 56
EP 58
DI 10.1038/362056a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600058
DA 2026-03-10
ER

PT J
AU BROCKE, S
   GAUR, A
   PIERCY, C
   GAUTAM, A
   GIJBELS, K
   FATHMAN, CG
   STEINMAN, L
AF BROCKE, S
   GAUR, A
   PIERCY, C
   GAUTAM, A
   GIJBELS, K
   FATHMAN, CG
   STEINMAN, L
TI INDUCTION OF RELAPSING PARALYSIS IN EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS BY BACTERIAL SUPERANTIGEN
SO NATURE
LA English
DT Article
ID experimental allergic encephalomyelitis; staphylococcal enterotoxin-b; myelin basic-protein; t-cells; mice; anergy; invivo
AB THE role of infection in the pathogenesis of clinical relapses that occur in most autoimmune diseases, including multiple sclerosis, remains to be established1,2. Experimental autoimmune encephalomyelitis (EAE) serves as a model for multiple sclerosis, with episodes of relapsing paralysis3-9. In certain strains of mice, T-lymphocytes expressing the Vbeta8 T-cell receptor (TCR)6-8 engage the amino-terminal epitope Ac1-11 of myelin basic protein, leading to EAE. The bacterial superantigen staphylococcal enterotoxin B (SEB) activates Vbeta8-expressing T cells. Here we show that after immunization with Ac1-11, or after transfer of encephalitogenic T-cell lines or clones reactive to Ac1-11, SEB induces exacerbation or relapses of paralytic disease in mice that are in clinical remission following an initial episode of paralysis, and triggers paralysis in mice with subclinical disease. Tumour necrosis factor has a critical role in the mechanism underlying SEB-induced exacerbation of disease, because anti-tumour necrosis factor antibody given in vivo delays the onset of paralysis triggered by SEB. On reactivation of autoaggressive cells through their T-cell receptor, superantigens may induce clinical relapses of autoimmune disease.
C1 STANFORD UNIV,MED CTR,SCH MED,DEPT MED,STANFORD,CA 94305.
C3 Stanford University
RP BROCKE, S (corresponding author), STANFORD UNIV,MED CTR,SCH MED,DEPT NEUROL & NEUROL SCI,STANFORD,CA 94305, USA.
NR 23
TC 237
Z9 267
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 642
EP 644
DI 10.1038/365642a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600057
PM 7692305
DA 2026-03-10
ER

PT J
AU BOEHLER, R
AF BOEHLER, R
TI TEMPERATURES IN THE EARTHS CORE FROM MELTING-POINT MEASUREMENTS OF IRON AT HIGH STATIC PRESSURES
SO NATURE
LA English
DT Article
ID gruneisen-parameter; phase-transitions; diagram; feo
AB THE temperature distribution in the Earth's core places important constraints on the Earth's internal heat budget and on models of the geodynamo. The solid inner core crystallizes from a liquid outer core, consisting mainly of iron alloyed with a lighter element, at a depth of about 5,100 km (corresponding to a pressure of about 3.3 Mbar). Thus, the most reliable means of determining the temperature gradient in the core is to estimate the melting temperature of iron and iron-rich compounds at the pressure of the inner core boundary. Current estimates range from about 4,000 to 8,000 K; but these estimates, obtained from shock compression1-3, theory (discussed in ref. 4) and extrapolation of static pressure data2,3,5 are poorly constrained. Here I present melting-point measurements on iron and iron-oxygen compounds at static pressures of up to 2 Mbar. Extrapolation of these results to 3.3 Mbar yields a temperature at the inner-core boundary of 4,850+/-200 K. A weak change in optical absorption observed above 2,000 K may correspond to the solid-solid phase transition found in shock experiments at 2 Mbar (ref. 1).
RP BOEHLER, R (corresponding author), MAX PLANCK INST CHEM,POSTFACH 3060,W-6500 MAINZ,GERMANY.
NR 19
TC 557
Z9 600
U1 2
U2 91
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 534
EP 536
DI 10.1038/363534a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900046
DA 2026-03-10
ER

PT J
AU LAFARGE, P
   JOYEZ, P
   ESTEVE, D
   URBINA, C
   DEVORET, MH
AF LAFARGE, P
   JOYEZ, P
   ESTEVE, D
   URBINA, C
   DEVORET, MH
TI 2-ELECTRON QUANTIZATION OF THE CHARGE ON A SUPERCONDUCTOR
SO NATURE
LA English
DT Article
ID electron
AB THE theoretical understanding of superconductors is based on the notion of electron pairing into Cooper pairs1. The first direct evidence for electron pairing was the observation that the flux threading a superconducting ring is always a multiple of the flux quantum, given by the ratio of Planck's constant to the Cooper-pair charge 2e (refs 2, 3). Here we report a direct measurement of the total charge on a superconducting electrode which is free to exchange electrons with a metallic reservoir through a tunnel junction. The total charge on a non-superconducting metal electrode has been shown previously4 to increase in jumps of 1e, corresponding to the addition of single electrons. We have also observed steps of 1e, with an even-odd asymmetry, for a superconducting electrode when the charging energy exceeds the energy gap between the ground and first excited superconducting state5. Our present measurements, with the charging energy below the gap, reveal charging steps strictly quantized in units of 2e, corresponding to the simultaneous tunnelling of two electrons. The 2e steps break into 1e steps when the temperature and magnetic field are increased above threshold values, corresponding to the electrostatic breaking of a single Cooper pair. Our results indicate that Cooper pairs can be manipulated in the same way as single electrons in turnstile and pump devices4.
RP LAFARGE, P (corresponding author), CENS, SERV PHYS ETAT CONDENSE, F-91191 GIF SUR YVETTE, FRANCE.
NR 19
TC 81
Z9 87
U1 1
U2 15
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 422
EP 424
DI 10.1038/365422a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300049
DA 2026-03-10
ER

PT J
AU MOCHKOVITCH, R
   HERNANZ, M
   ISERN, J
   MARTIN, X
AF MOCHKOVITCH, R
   HERNANZ, M
   ISERN, J
   MARTIN, X
TI GAMMA-RAY BURSTS AS COLLIMATED JETS FROM NEUTRON-STAR BLACK-HOLE MERGERS
SO NATURE
LA English
DT Article
ID optically thick; binary; winds
AB THE distribution of more than 150 gamma-ray bursts detected by the BATSE experiment is isotropic on the sky but radially nonuniform1,2. This raises the possibility that bursts are cosmological (at z less than or similar 1) and therefore very energetic events, releasing approximately 10(50) erg sr-1 on a timescale of seconds. The coalescence of two neutron stars 3-7 or the accretion-induced collapse of a white dwarf8 can release up to 10(53) erg in the form of neutrino-antineutrino pairs, so that the conversion of < 1% into gamma-rays by annihilation9 could generate gamma-ray bursts, but in all such models an optically thick wind tends to form10,11, preventing the gamma-rays from escaping and converting their energy into kinetic energy of the ejected material. We present here a possible solution to this difficulty. When a stellar-mass neutron star is disrupted by a black hole, it forms a thick disk which emits nunuBAR pairs. These neutrinos expel a wind from the disk, but angular momentum conservation means that a clear funnel forms along the rotation axis. Neutrino annihilation within the matter-free funnel can then create gamma-rays which escape to the distant observer.
C1 CSIC,CTR ESTUDIS AVANCATS BLANES,E-17300 BLANES,SPAIN.
   UNIV BARCELONA,INST ESTUDIS CATALANS,ASTROFIS LAB,E-08028 BARCELONA,SPAIN.
C3 Consejo Superior de Investigaciones Cientificas (CSIC); CSIC - Centre d'Estudis Avancats de Blanes (CEAB); University of Barcelona
RP MOCHKOVITCH, R (corresponding author), INST ASTROPHYS PARIS,98BIS BLVD ARAGO,F-75014 PARIS,FRANCE.
NR 24
TC 211
Z9 225
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 236
EP 238
DI 10.1038/361236a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400050
DA 2026-03-10
ER

PT J
AU GLATT, CE
   SNYDER, SH
AF GLATT, CE
   SNYDER, SH
TI CLONING AND EXPRESSION OF AN ADENYLYL CYCLASE LOCALIZED TO THE CORPUS STRIATUM
SO NATURE
LA English
DT Article
ID messenger-rna; rat-brain; insitu hybridization; localizations
AB THE neurotransmitter dopamine acts through various receptor subtypes that are largely associated with enhancement or inhibition of adenylyl cyclases1,2. These dopamine-sensitive adenylyl cyclases are highly concentrated in the corpus striatum and associated limbic structures of the brain, where their levels exceed by orders of magnitude 3,4 those in other areas of the brain. Here we use in situ hybridization to show that messenger RNA for three of these adenylyl cyclases5-7 is not found in the corpus striatum. We have isolated and expressed a complementary DNA encoding new adenylyl cyclase whose selective concentration in the corpus striatum indicates that it may be responsible for the synaptic actions of dopamine.
C1 JOHNS HOPKINS UNIV,SCH MED,DEPT PSYCHIAT,BALTIMORE,MD 21205.
   JOHNS HOPKINS UNIV,SCH MED,DEPT PHARMACOL & MOLEC SCI,BALTIMORE,MD 21205.
C3 Johns Hopkins University; Johns Hopkins University
RP GLATT, CE (corresponding author), JOHNS HOPKINS UNIV,SCH MED,DEPT NEUROSCI,725 N WOLFE ST,BALTIMORE,MD 21205, USA.
NR 18
TC 188
Z9 203
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 536
EP 538
DI 10.1038/361536a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400060
PM 8429907
DA 2026-03-10
ER

PT J
AU LIU, B
   WONG, ML
   TINKER, RL
   GEIDUSCHEK, EP
   ALBERTS, BM
AF LIU, B
   WONG, ML
   TINKER, RL
   GEIDUSCHEK, EP
   ALBERTS, BM
TI THE DNA-REPLICATION FORK CAN PASS RNA-POLYMERASE WITHOUT DISPLACING THE NASCENT TRANSCRIPT
SO NATURE
LA English
DT Article
ID escherichia-coli; magnetic-resonance; ternary complexes; late promoters; bacteriophage-t4; protein; initiation; elongation; site; termination
AB Replication proteins encoded by bacteriophage T4 generate DNA replication forks that can pass a molecule of Escherichia coli RNA polymerase moving in the same direction as the fork in vitro. The RNA polymerase ternary transcription complex remains bound to the DNA and retains a transcription bubble after the fork passes. The by-passed ternary complex can resume faithful RNA synthesis, suggesting that the multisubunit RNA polymerase of E. coli has evolved to retain its transcript after DNA replication, allowing partially completed transcripts to be elongated into full-length RNA molecules.
C1 UNIV CALIF SAN DIEGO,DEPT BIOL,LA JOLLA,CA 92093.
   UNIV CALIF SAN FRANCISCO,DEPT BIOCHEM & BIOPHYS,SAN FRANCISCO,CA 94143.
C3 University of California System; University of California San Diego; University of California System; University of California San Francisco
NR 47
TC 92
Z9 103
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 33
EP 39
DI 10.1038/366033a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700045
PM 8232535
DA 2026-03-10
ER

PT J
AU RICE, WG
   SCHAEFFER, CA
   HARTEN, B
   VILLINGER, F
   SOUTH, TL
   SUMMERS, MF
   HENDERSON, LE
   BESS, JW
   ARTHUR, LO
   MCDOUGAL, JS
   ORLOFF, SL
   MENDELEYEV, J
   KUN, E
AF RICE, WG
   SCHAEFFER, CA
   HARTEN, B
   VILLINGER, F
   SOUTH, TL
   SUMMERS, MF
   HENDERSON, LE
   BESS, JW
   ARTHUR, LO
   MCDOUGAL, JS
   ORLOFF, SL
   MENDELEYEV, J
   KUN, E
TI INHIBITION OF HIV-1 INFECTIVITY BY ZINC-EJECTING AROMATIC C-NITROSO COMPOUNDS
SO NATURE
LA English
DT Article
ID murine leukemia-virus; stranded nucleic-acids; nucleocapsid protein; dimer formation; finger domain; metal-ions; viral-rna; binding; polymerase; sequence
AB RETROVIRAL nucleocapsid and gag-precursor proteins from all known strains of retroviruses contain one or two copies of an invariant sequence, Cys-X2-Cys-X4-His-X4-Cys1,2, that is populated with zinc in mature particles3. Modification of cysteine or histidine residues results in defective packaging of genomic viral RNA and formation of non-infectious particles4-8, making these structures potentially attractive targets for antiviral therapy3,8. We recently reported that aromatic C-nitroso ligands of poly(ADP-ribose) polymerase preferentially destabilize one of the two (CYS-X2-CYS-X28-His-X2-Cys) zinc-fingers with concomitant loss of enzymatic activity9,10, coincidental with selective cytocidal action of the C-nitroso substituted ligands on cancer cells11. Based on the occurrence of (3Cys, 1His) zinc-binding sites in both retroviral nucleocapsid and gag proteins and in poly(ADP-ribose) polymerase12, we reasoned that the C-nitroso compounds may also have antiretroviral effects. We show here that two such compounds, 3-nitrosobenzamide and 6-nitroso-1,2-benzopyrone, inhibit infection of human immunodeficiency virus HIV-1 in human lymphocytes and also eject zinc from isolated HIV-1 nucleocapsid zinc fingers and from intact HIV-1 virions. Thus the design of zinc-ejecting agents that target retroviral zinc fingers represents a new approach to the chemotherapy of AIDS.
C1 NCI,FREDERICK CANC RES & DEV CTR,PROGRAM RESOURCES INC DYNCORP,AIDS VACCINE PROGRAM,FREDERICK,MD 21702.
   EMORY UNIV,SCH MED,DEPT PATHOL & LAB MED,ATLANTA,GA 30322.
   CTR DIS CONTROL,NCID,DHA,IMMUNOL BRANCH,ATLANTA,GA 30333.
   OCTAMER INC,TIBURON,CA 94920.
   SAN FRANCISCO STATE UNIV,ROMBERG TIBURON CTR,ENVIRONM TOXICOL & CHEM LAB,TIBURON,CA 94920.
C3 National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI); Science Applications International Corporation (SAIC); SAIC-Frederick; Emory University; Centers for Disease Control & Prevention - USA; California State University System; San Francisco State University
RP RICE, WG (corresponding author), NCI,FREDERICK CANC RES & DEV CTR,ANTIVIRAL DRUG MECHANISMS LAB,FREDERICK,MD 21702, USA.
NR 34
TC 212
Z9 245
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 473
EP 475
DI 10.1038/361473a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300068
PM 8429889
DA 2026-03-10
ER

PT J
AU CLAPHAM, DE
   NEER, EJ
AF CLAPHAM, DE
   NEER, EJ
TI NEW ROLES FOR G-PROTEIN BETA-GAMMA-DIMERS IN TRANSMEMBRANE SIGNALING
SO NATURE
LA English
DT Article
ID muscarinic k+-channel; gtp-binding proteins; phospholipase-c; adenylyl cyclase; regulatory proteins; subunit activation; transduction; receptors; membrane; kinase
AB When a membrane-bound receptor acts on a G protein, the GTP-binding or G(alpha) subunit dissociates from the G(betagamma) dimer. Until recently, the G(alpha) subunit alone was thought to act on the enzymes and ion channels controlled by these proteins. Newer evidence indicates that the G(betagamma) dimer also plays a major part in signal transmission, enhancing the complexity of the possible interactions between the G proteins and their targets.
C1 HARVARD UNIV, SCH MED, BOSTON, MA 02115 USA.
   BRIGHAM & WOMENS HOSP, DEPT MED, BOSTON, MA 02115 USA.
C3 Harvard University; Harvard Medical School; Harvard University; Harvard University Medical Affiliates; Brigham & Women's Hospital
RP CLAPHAM, DE (corresponding author), MAYO CLIN & MAYO FDN, DEPT PHARMACOL, GUGGENHEIM 7, ROCHESTER, MN 55905 USA.
NR 71
TC 627
Z9 679
U1 0
U2 15
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 403
EP 406
DI 10.1038/365403a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300045
PM 8413584
DA 2026-03-10
ER

PT J
AU ANDERSON, RS
   BUNAS, KL
AF ANDERSON, RS
   BUNAS, KL
TI GRAIN-SIZE SEGREGATION AND STRATIGRAPHY IN AEOLIAN RIPPLES MODELED WITH A CELLULAR-AUTOMATON
SO NATURE
LA English
DT Article
ID self-organization
AB AEOLIAN ripples are distinguished by coarse-grained crests, fine-grained troughs, and thin veneers of coarse grains on the upwind (stoss) slopes. Migration of these sorted bedforms during periods of net deposition results in a characteristic inversely graded stratigraphy that distinguishes aeolian sandstones from those of fluvial origin1. Here we investigate the formation and evolution of aeolian ripples using a cellular automaton model of a sandbed which incorporates two grain sizes and is subject to the impacts of episodically hopping (saltating) grains. Using this model, we identify the physical processes responsible for both the spatial sorting and the stratigraphic signature of the ripples. High-energy saltating grains are found to eject small grains preferentially from the impact site, leading to a coarsening of the heavily bombarded stoss slopes. Coarse grains do not in general leap far enough to escape the shadow zones on the downwind (lee) slopes, and therefore tend to accumulate and cycle around the ripple crests. Small grains, on the other hand, are ejected at higher velocities, enabling them to hop further. Incorporating net deposition into the model results in a stratigraphy closely resembling thin planar laminae ('pinstriping') found in aeolian sandstones: the inverse grading of grain sizes is a direct consequence of their different hop lengths.
C1 UNIV CALIF SANTA CRUZ,COMPUTAT MATH PROGRAM,SANTA CRUZ,CA 95064.
C3 University of California System; University of California Santa Cruz
RP ANDERSON, RS (corresponding author), UNIV CALIF SANTA CRUZ,DEPT EARTH SCI,SANTA CRUZ,CA 95064, USA.
NR 10
TC 107
Z9 133
U1 0
U2 43
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 740
EP 743
DI 10.1038/365740a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200058
DA 2026-03-10
ER

PT J
AU CRAWLEY, MJ
   HAILS, RS
   REES, M
   KOHN, D
   BUXTON, J
AF CRAWLEY, MJ
   HAILS, RS
   REES, M
   KOHN, D
   BUXTON, J
TI ECOLOGY OF TRANSGENIC OILSEED RAPE IN NATURAL HABITATS
SO NATURE
LA English
DT Article
AB CONCERNS about genetically engineered crop plants centre on three conjectural risks: that transgenic crop plants will become weeds of agriculture or invasive of natural habitats; that their engineered genes will be transferred by pollen to wild relatives whose hybrid offspring will then become more weedy or more invasive; or that the engineered plants will be a direct hazard to humans, domestic animals or beneficial wild organisms (toxic or allergenic, for example). Here we describe an experimental protocol for assessing the invasiveness of plants. The object is to determine whether genetic engineering for herbicide tolerance affects the likelihood of oilseed rape becoming invasive of natural habitats. By estimating the demographic parameters of transgenic and conventional oilseed rape growing in a variety of habitats and under a range of climatic conditions, we obtain a direct comparison of the ecological performance of three different genetic lines (control, kanamycin-tolerant transgenics and herbicide-tolerant transgenic lines). Despite substantial variation in seed survival, lines were less invasive and less persistent than their conventional counter arts.
C1 INST VIROL & ENVIRONM MICROBIOL,OXFORD OX1 3SR,ENGLAND.
C3 UK Centre for Ecology & Hydrology (UKCEH)
RP CRAWLEY, MJ (corresponding author), UNIV LONDON IMPERIAL COLL SCI & TECHNOL,DEPT BIOL,SILWOOD PK,ASCOT SL5 7PY,BERKS,ENGLAND.
NR 9
TC 233
Z9 262
U1 0
U2 35
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 620
EP 623
DI 10.1038/363620a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900053
DA 2026-03-10
ER

PT J
AU AJAYAN, PM
   IIJIMA, S
AF AJAYAN, PM
   IIJIMA, S
TI CAPILLARITY-INDUCED FILLING OF CARBON NANOTUBES
SO NATURE
LA English
DT Article
AB THE recent discovery1 and bulk synthesis2 of nanometre-scale carbon tubules has led to much speculation about possible uses of these graphitic structures3-5. Broughton and Pederson predicted on the basis of computer simulations that open nanotubes may be filled with liquid by capillary suction6. Here we describe experiments in which annealing of the tubules in the presence of liquid lead results in opening of the capped tube ends and subsequent filling of the tubes with molten material through capillary action. The nanotubes thus act as moulds for the fabrication of (possibly metallic) wires, some of which are less than two nanometres in diameter.
RP AJAYAN, PM (corresponding author), NEC CORP LTD,FUNDAMENTAL RES LAB,34 MIYUKIGAOKA,TSUKUBA,IBARAKI 305,JAPAN.
NR 7
TC 1411
Z9 1555
U1 3
U2 338
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 333
EP 334
DI 10.1038/361333a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000049
DA 2026-03-10
ER

PT J
AU CURTIS, R
   ADRYAN, KM
   ZHU, Y
   HARKNESS, PJ
   LINDSAY, RM
   DISTEFANO, PS
AF CURTIS, R
   ADRYAN, KM
   ZHU, Y
   HARKNESS, PJ
   LINDSAY, RM
   DISTEFANO, PS
TI RETROGRADE AXONAL-TRANSPORT OF CILIARY NEUROTROPHIC FACTOR IS INCREASED BY PERIPHERAL-NERVE INJURY
SO NATURE
LA English
DT Article
ID factor prevents; sciatic-nerve; motor neurons; growth-factor; rat; degeneration; expression; receptor; invivo; bdnf
AB CILIARY neurotrophic factor (CNTF) promotes the survival of several populations of neurons. including sensory and motor neurons1-4. Although CNTF is abundant in adult sciatic nerve, the mature protein lacks a signal sequence and is not secreted; therefore, it has been proposed to act as a lesion factor3. The identification of a functional CNTF receptor revealed ligand-specific phosphorylation cascades and gene induction5. However, it is not clear how these signal-transducing events are elicited in neuronal cell bodies that may be distant from the source of CNTF. We report here that CNTF can be retrogradely transported by adult sensory neurons. More importantly, sensory and motor neurons both show greatly increased transport of CnTF following peripheral nerve lesion. Axotomy-induced increases in retrograde transport of neurotrophic factors may be an important response of neuronal cell bodies during regeneration.
RP CURTIS, R (corresponding author), REGENERON PHARMACEUT INC,777 OLD SAW MILL RIVER RD,TARRYTOWN,NY 10591, USA.
NR 27
TC 225
Z9 244
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 253
EP 255
DI 10.1038/365253a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100054
PM 8371780
DA 2026-03-10
ER

PT J
AU KULKARNI, SR
   HUT, P
   MCMILLAN, S
AF KULKARNI, SR
   HUT, P
   MCMILLAN, S
TI STELLAR BLACK-HOLES IN GLOBULAR-CLUSTERS
SO NATURE
LA English
DT Article
ID binary-systems; neutron-stars; pulsars; mass; evolution; collapse
AB FOLLOWING the discovery of X-ray sources in globular clusters, the accretion of matter onto a central massive black hole was suggested1-3 as a possible explanation. Subsequently, it was found4,5 that these sources could be readily explained by thermonuclear instabilities on neutron-star surfaces and the black-hole models were abandoned. We show here, however, that the recent discovery6 of large populations of millisecond pulsars-and hence neutron stars-in globular clusters implies that several hundred stellar black holes (of about ten solar masses) should form within a typical cluster. In clusters of high central density, we find that the rapid dynamical evolution of the black-hole population will cause ejection of nearly all of the holes on a relatively short timescale. But in systems of intermediate density, some of the surviving holes may capture a normal star to form a low-mass X-rav binary. We suggest that there may be one or more such binaries in the globular clusters surrounding our Galaxy. These systems will be quiescent most of the time-with only occasional X-ray outbursts-but future observations of the hard X-ray spectrum may indirectly establish their existence.
C1 INST ADV STUDY,PRINCETON,NJ 08540.
   DREXEL UNIV,DEPT PHYS & ATMOSPHER SCI,PHILADELPHIA,PA 19104.
C3 Institute for Advanced Study - USA; Drexel University
RP KULKARNI, SR (corresponding author), CALTECH,DIV PHYS MATH & ASTRON,105-24,PASADENA,CA 91125, USA.
NR 30
TC 252
Z9 280
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 421
EP 423
DI 10.1038/364421a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000046
DA 2026-03-10
ER

PT J
AU SMITH, TB
AF SMITH, TB
TI DISRUPTIVE SELECTION AND THE GENETIC-BASIS OF BILL SIZE POLYMORPHISM IN THE AFRICAN FINCH PYRENESTES
SO NATURE
LA English
DT Article
ID natural-selection; morphs; ostrinus
AB MECHANISMS producing and maintaining discrete polymorphisms have long fascinated evolutionary biologists1,2. Despite the ubiquity of non-sex-limited polymorphisms in vertebrates, the evolutionary factors maintaining them are well understood in only a few instances3. The African finch Pyrenestes is unique among birds in exhibiting a non-sex-determined polymorphism in bill size4,5. Morphs breed randomly with respect to bill size and differ in diet and feeding performance on soft and hard seeds4,6. I present here: (1) new data showing that the polymorphism appears to result from a single genetic factor; (2) support from long-term field studies for earlier suggestions that disruptive selection is acting on bill size; and (3) data revealing the presence of a possible third, much larger morph. Results suggest that the polymorphism may have arisen through single mutations, where morphs occupy distinct adaptive peaks through differences in feeding performance on seeds differing in hardness.
RP SMITH, TB (corresponding author), SAN FRANCISCO STATE UNIV,DEPT BIOL,1600 HOLLOWAY AVE,SAN FRANCISCO,CA 94132, USA.
NR 18
TC 162
Z9 183
U1 0
U2 69
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 618
EP 620
DI 10.1038/363618a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900052
DA 2026-03-10
ER

PT J
AU LOWEY, S
   WALLER, GS
   TRYBUS, KM
AF LOWEY, S
   WALLER, GS
   TRYBUS, KM
TI SKELETAL-MUSCLE MYOSIN LIGHT-CHAINS ARE ESSENTIAL FOR PHYSIOLOGICAL SPEEDS OF SHORTENING
SO NATURE
LA English
DT Article
ID scallop myosin; heavy-chains; actin; subfragment-1; microscopy; antibody; velocity; binding; invitro; fibers
AB IN muscle each myosin head contains a regulatory light chain (LC2) that is wrapped around the head/rod junction, and an alkali light chain that is distal to LC2 (ref. 1). The role of these light chains in vertebrate skeletal muscle myosin has remained obscure2,3. Here we prepare heavy chains that are free of both light chains in order to determine by a motility assay4 whether the light chains are necessary for movement. We find that removal of light chains from myosin reduces the velocity of actin filaments from 8.8 mum s-1 to 0.8 mum s-1 without significantly decreasing the ATPase activity. Reconstitution of myosin with LC2 or alkali light chain increases filament velocity to intermediate rates, and readdition of both classes of light chains fully restores the original sliding velocity. We conclude that even though the light chains are not essential for enzymatic activity, light-chain/heavy-chain interactions play an important part in the conversion of chemical energy into movement.
RP LOWEY, S (corresponding author), BRANDEIS UNIV,ROSENSTIEL BASIC MED SCI RES CTR,WALTHAM,MA 02254, USA.
NR 19
TC 287
Z9 312
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 454
EP 456
DI 10.1038/365454a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300060
PM 8413589
DA 2026-03-10
ER

PT J
AU SHUAL, K
   ZIEMIECKI, A
   WILKS, AF
   HARPUR, AG
   SADOWSKI, HB
   GILMAN, MZ
   DARNELL, JE
AF SHUAL, K
   ZIEMIECKI, A
   WILKS, AF
   HARPUR, AG
   SADOWSKI, HB
   GILMAN, MZ
   DARNELL, JE
TI POLYPEPTIDE SIGNALING TO THE NUCLEUS THROUGH TYROSINE PHOSPHORYLATION OF JAK AND STAT PROTEINS
SO NATURE
LA English
DT Article
AB BINDING of interferons IFN-alpha and IFN-gamma to their cell surface receptors promptly induces tyrosine phosphorylation of latent cytoplasmic transcriptional activators1-4 (or Stat proteins, for signal transducers and activators of transcription). Interferon-alpha activates both Stat91 (M(r) 91,000; ref. 1) and Stat113 (M(r) 113,000; ref. 2) whereas IFN-gamma activates only Stat91 (refs 3, 4). The activated proteins then move into the nucleus and directly activate genes induced by IFN-alpha and IFN-gamma. Somatic cell genetics experiments have demonstrated a requirement for tyrosine kinase-2 (Tyk2) in the IFN-alpha response pathway5 and for Jak2 (ref. 6), a kinase with similar sequence7, in the IFN-gamma response pathway. Here we investigate the tyrosine phosphorylation events on Stat and Jak proteins after treatment of cells with IFNs alpha and gamma and with epidermal growth factor (EGF). Stat91 is phosphorylated on Tyr 701 after cells are treated with IFN-alpha and EGF, as it was after treatment with IFN-gamma (ref. 8). We find that Jak1 also becomes phosphorylated on tyrosine after cells are treated with these same three ligands, although each ligand is shown to activate at least one other different kinase. Jak1 may therefore be the enzyme that phosphorylates Tyr 701 in Stat91.
C1 UNIV BERN, INST CLIN & EXPTL CANC RES, CH-3004 BERN, SWITZERLAND.
   ROYAL MELBOURNE HOSP, LUDWIG INST CANC RES, PARKVILLE, VIC 3050, AUSTRALIA.
   COLD SPRING HARBOR LAB, COLD SPRING HARBOR, NY 11724 USA.
C3 University of Bern; Melbourne Health; Royal Melbourne Hospital; Ludwig Institute for Cancer Research; Cold Spring Harbor Laboratory
RP SHUAL, K (corresponding author), ROCKEFELLER UNIV, MOLEC CELL BIOL LAB, 1230 YORK AVE, NEW YORK, NY 10021 USA.
NR 28
TC 470
Z9 529
U1 2
U2 13
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 580
EP 583
DI 10.1038/366580a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800074
PM 7504784
DA 2026-03-10
ER

PT J
AU MOMBAERTS, P
   ARNOLDI, J
   RUSS, F
   TONEGAWA, S
   KAUFMANN, SHE
AF MOMBAERTS, P
   ARNOLDI, J
   RUSS, F
   TONEGAWA, S
   KAUFMANN, SHE
TI DIFFERENT ROLES OF ALPHA-BETA AND GAMMA-DELTA T-CELLS IN IMMUNITY AGAINST AN INTRACELLULAR BACTERIAL PATHOGEN
SO NATURE
LA English
DT Article
ID delayed-type hypersensitivity; listeria-monocytogenes; mediated-immunity; infection; mice; protection; interferon; lymphocytes; expression; resolution
AB SEVERAL bacterial pathogens of medical importance are able to persist and replicate inside host mononuclear phagocytes. Protective immunity depends on specific T lymphocytes that induce granulomatous lesions at the sites of bacterial multiplication1,2. Listeria monocytogenes is an intracellular pathogen that replicates inside mononuclear phagocytes and hepatocytes of mice1-4.  Invasion from the phagosomal compartment into the cytoplasmic compartment is the principal mechanism of intracellular survival5. Early in infection, resistance against L. monocytogenes is mediated by polymorphonuclear phagocytes which destroy infected liver cells, followed by natural killer cells which activate macrophages by means of interferon-gamma (refs 6, 7). A specific immune response by T cells then develops which leads to sterile eradication of the microbes1,2,8. T cells are also responsible for the highly effective protection in vaccinated mice against secondary infections1,2.  Although the role of alphabeta T cells has been demonstrated in these immune responses, that of gammadelta T cells is unclear2,9,10. Here we use mice that selectively lack either alphabeta or gammadelta T cells as a result of targeted germ-line mutations in their T-cell receptor genes11,12 to investigate the relative roles of these T-cell populations during experimental infection with L. monocytogenes. We find that in primary listeriosis, either alphabeta or gammadelta T cells are sufficient for early protection. Resistance to secondary infection is mediated mainly by alphabeta T cells but also involves gammadelta T cells. Thus alphabeta T-cell-deficient mice can be rendered partially resistant by vaccination, and gammadelta T cells are shown to be responsible for this protective effect. In infected gammadelta T-cell-deficient mice we noticed the appearance of unusual liver lesions, indicating that gammadelta T cells have a unique regulatory role in this bacterial infection.
C1 UNIV ULM,DEPT IMMUNOL,ALBERT EINSTEIN ALLEE 11,D-89070 ULM,GERMANY.
   MIT,DEPT BIOL,CTR CANC RES,HOWARD HUGHES MED INST,CAMBRIDGE,MA 02139.
C3 Ulm University; Howard Hughes Medical Institute; Massachusetts Institute of Technology (MIT)
NR 25
TC 416
Z9 437
U1 0
U2 18
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 53
EP 56
DI 10.1038/365053a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600052
PM 8361537
DA 2026-03-10
ER

PT J
AU CHIBA, T
   NAGATA, Y
   MACHIDE, M
   KISHI, A
   AMANUMA, H
   SUGIYAMA, M
   TODOKORO, K
AF CHIBA, T
   NAGATA, Y
   MACHIDE, M
   KISHI, A
   AMANUMA, H
   SUGIYAMA, M
   TODOKORO, K
TI TYROSINE KINASE ACTIVATION THROUGH THE EXTRACELLULAR DOMAINS OF CYTOKINE RECEPTORS
SO NATURE
LA English
DT Article
ID cell-lines; phosphorylation; erythropoietin; proteins; genes
AB INTERACTION of cytokines with their membrane receptors induces the proliferation and differentiation of a specific lineage of haematopoietic progenitors1. The molecular mechanism of cytokine receptor-mediated signal transduction is unclear because these receptors do not have tyrosine kinase activity1-2. Interleukin-3 and erythropoietin, however, induce transient tyrosine phosphorylation of a common set of proteins as a growth signal3-6 and interleukin-2 induces phosphorylation of an overlapping but distinct set of proteins6-8. Here we show that chimaeric receptors consisting of the extracellular domains of the erythropoietin receptor and the cytoplasmic domains of the interleukin-2 (or interleukin-3) receptor induce an erythropoietin-dependent tyrosine phosphorylation in interleukin-3-dependent Ba/F3 cells; however, chimaeric receptors composed of the extracellular domains of the interleukin-2 receptor and the cytoplasmic domains of the erythropoietin (or interleukin-3) receptor apparently transmit an interleukin-2-dependent signal. Our results indicate that these cytokines transmit distinct signals for activation of specific tyrosine kinases through the extracellular rather than cytoplasmic domains of the receptors.
C1 INST PHYS & CHEM RES,TSUKUBA LIFE SCI CTR,3-1 KOYADAI,TSUKUBA,IBARAKI 305,JAPAN.
C3 RIKEN
NR 17
TC 76
Z9 78
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 646
EP 648
DI 10.1038/362646a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800053
PM 8464516
DA 2026-03-10
ER

PT J
AU LEVINE, B
   HUANG, Q
   ISAACS, JT
   REED, JC
   GRIFFIN, DE
   HARDWICK, JM
AF LEVINE, B
   HUANG, Q
   ISAACS, JT
   REED, JC
   GRIFFIN, DE
   HARDWICK, JM
TI CONVERSION OF LYTIC TO PERSISTENT ALPHAVIRUS INFECTION BY THE BCL-2 CELLULAR ONCOGENE
SO NATURE
LA English
DT Article
ID follicular lymphoma; b-cells; death; apoptosis; gene; expression; virus; protein; lines
AB LITTLE is known about virus-host cell interactions that regulate the lytic potential of viruses during productive replication. Sindbis virus (SV), a single-stranded positive-sense RNA virus in the alphavirus genus (family Togaviridae), results in lytic infection in most vertebrate cell lines, but persistent productive infection in post-mitotic neurons1. The cellular oncogene bcl-2, which encodes an inner mitochondrial membrane protein of M(r) 26,000 (ref. 2), blocks programmed cell death (apoptosis) in neurons3. We therefore investigated whether SV infection induces programmed cell death in non-neuronal cells, and if so, whether virus-induced programmed cell death can be blocked by transfection with bcl-2. We demonstrate that SV infection of baby hamster kidney (BHK-2), mouse neuroblastoma (N18), and rat prostatic adenocarcinoma (AT-3) cells results in programmed cell death, whereas SV infection of bcl-2-transfected AT-3 cells results in long-term persistent productive infection. Thus cellular bcl-2 oncogene expression plays a role in the establishment of persistent viral infection by blocking virus-induced programmed cell death.
C1 JOHNS HOPKINS UNIV, SCH MED, DEPT PHARMACOL & MOLEC SCI, BALTIMORE, MD 21287 USA.
   JOHNS HOPKINS UNIV, SCH MED, DEPT MED, BALTIMORE, MD 21287 USA.
   JOHNS HOPKINS UNIV, SCH MED, DEPT ONCOL, BALTIMORE, MD 21287 USA.
   JOHNS HOPKINS UNIV, SCH MED, DEPT UROL, BALTIMORE, MD 21287 USA.
   JOHNS HOPKINS UNIV, SCH MED, DEPT NEUROL, BALTIMORE, MD 21287 USA.
   LA JOLLA CANC RES FDN, CANC RES INST, LA JOLLA, CA 92037 USA.
C3 Johns Hopkins University; Johns Hopkins University; Johns Hopkins University; Johns Hopkins University; Johns Hopkins University; Sanford Burnham Prebys Medical Discovery Institute
NR 28
TC 451
Z9 506
U1 0
U2 19
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 739
EP 742
DI 10.1038/361739a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900061
PM 8441470
DA 2026-03-10
ER

PT J
AU ZOBACK, MD
   APEL, R
   BAUMGARTNER, J
   BRUDY, M
   EMMERMANN, R
   ENGESER, B
   FUCHS, K
   KESSELS, W
   RISCHMULLER, H
   RUMMEL, F
   VERNIK, L
AF ZOBACK, MD
   APEL, R
   BAUMGARTNER, J
   BRUDY, M
   EMMERMANN, R
   ENGESER, B
   FUCHS, K
   KESSELS, W
   RISCHMULLER, H
   RUMMEL, F
   VERNIK, L
TI UPPER-CRUSTAL STRENGTH INFERRED FROM STRESS MEASUREMENTS TO 6 KM DEPTH IN THE KTB BOREHOLE
SO NATURE
LA English
DT Article
ID continental lithosphere; tectonic stresses; deformation; constraints; magnitude; patterns; model; rates; plate; rocks
AB IT has been suggested1-6 that in many cases the average strength of the continental crust is quite low (tens of megapascals), so that the crust has little effect on the large-scale deformation of the lithosphere. But laboratory friction studies7,8, combined with simple faulting theory9,10 (as well as extrapolation of in situ stress measurements from the upper 3 km of the crust11), imply that if pore pressure is approximately hydrostatic at mid-crustal depth, crustal strength is appreciable (hundreds of megapascals) and would markedly constrain the nature of lithospheric deformation12-15. Here we report estimates of the magnitude of in situ stresses to 6 km depth in the KTB borehole in southern Germany. Our results indicate a high-strength upper crust, in which the state of stress is in equilibrium with its frictional strength. We suggest that plate-driving forces in the continental lithosphere in this part of western Europe are transmitted principally through the upper crust, and that this may also be the case in other continental areas of moderate to elevated heat flow.
C1 UNIV KARLSRUHE, INST GEOPHYS, D-76187 KARLSRUHE, GERMANY.
   SOCOMINE, F-67250 Soultz Sous Forets, FRANCE.
   GEOL SURVEY LOWER SAXONY, KTB PROJECT, D-30655 HANNOVER, GERMANY.
   RUHR UNIV BOCHUM, DEPT GEOPHYS, D-44780 BOCHUM, GERMANY.
C3 Helmholtz Association; Karlsruhe Institute of Technology; Ruhr University Bochum
RP ZOBACK, MD (corresponding author), STANFORD UNIV, DEPT GEOPHYS, STANFORD, CA 94305 USA.
NR 37
TC 133
Z9 154
U1 0
U2 17
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 633
EP 635
DI 10.1038/365633a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600054
DA 2026-03-10
ER

PT J
AU HABRAKEN, Y
   SUNG, P
   PRAKASH, L
   PRAKASH, S
AF HABRAKEN, Y
   SUNG, P
   PRAKASH, L
   PRAKASH, S
TI YEAST EXCISION-REPAIR GENE RAD2 ENCODES A SINGLE-STRANDED-DNA ENDONUCLEASE
SO NATURE
LA English
DT Article
ID saccharomyces-cerevisiae; complex; protein; homolog; ssl2
AB IN eukaryotes nucleotide excision repair of DNA damaged by ultraviolet radiation requires several gene products; defects in this process result in the cancer-prone syndrome xeroderma pigmentosum (XP) in humans1,2. The RAD2 gene is one of at least seven genes indispensable for excision repair in the yeast Saccharomyces cerevisiae2, and its encoded protein shares remarkable homology with the XP group-G gene product3. Here we overproduce the RAD2-encoded protein in S. cerevisiae, purify it to near homogeneity, and show that RAD2 protein in the presence of magnesium degrades circular single-stranded DNA. The RAD2 endonuclease is specific for single-stranded DNA as it does not act on double-stranded DNA. Given the absolute requirement for RAD2 in the incision step of excision repair, our findings directly implicate RAD2 protein and its human homologue XPG protein as a catalytic component that incises the damaged DNA strand during excision repair. Furthermore, our results indicate that eukaryotes probably employ two distinct endonuclease activities to mediate the dual incision at the damage site.
C1 UTMB,SEALY CTR MOLEC SCI,MED RES BLDG,ROUTE J61,11TH ST & MECH,GALVESTON,TX 77555.
C3 University of Texas System; University of Texas Medical Branch Galveston
NR 16
TC 125
Z9 143
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 365
EP 368
DI 10.1038/366365a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500055
PM 8247134
DA 2026-03-10
ER

PT J
AU SERRANO, M
   HANNON, GJ
   BEACH, D
AF SERRANO, M
   HANNON, GJ
   BEACH, D
TI A NEW REGULATORY MOTIF IN CELL-CYCLE CONTROL CAUSING SPECIFIC-INHIBITION OF CYCLIN-D/CDK4
SO NATURE
LA English
DT Article
ID protein-kinases
AB THE division cycle of eukaryotic cells is regulated by a family of protein kinases known as the cyclin-dependent kinases (CDKs)1,2. The sequential activation of individual members of this family and their consequent phosphorylation of critical substrates promotes orderly progression through the cell cycle3,4. The complexes formed by CDK4 and the D-type cyclins have been strongly implicated in the control of cell proliferation during the G1 phase3-6. CDK4 exists, in part, as a multi-protein complex with a D-type cyclin, proliferating cell nuclear antigen and a protein, p21 (refs 7-9). CDK4 associates separately with a protein of M(r) 16K, particularly in cells lacking a functional retinoblastoma protein9. Here we report the isolation of a human p16 complementary DNA and demonstrate that p16 binds to CDK4 and inhibits the catalytic activity of the CDK4/cyclin D enzymes. p16 seems to act in a regulatory feedback circuit with CDK4, D-type cyclins and retino-blastoma protein.
C1 COLD SPRING HARBOR LAB, HOWARD HUGHES MED INST, POB 100, COLD SPRING HARBOR, NY 11724 USA.
C3 Howard Hughes Medical Institute; Cold Spring Harbor Laboratory
NR 23
TC 3525
Z9 4015
U1 1
U2 169
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 704
EP 707
DI 10.1038/366704a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500075
PM 8259215
DA 2026-03-10
ER

PT J
AU ODOR, RK
   FORSYTHE, J
   WEBBER, DM
   WELLS, J
   WELLS, MJ
AF ODOR, RK
   FORSYTHE, J
   WEBBER, DM
   WELLS, J
   WELLS, MJ
TI ACTIVITY LEVELS OF NAUTILUS IN THE WILD
SO NATURE
LA English
DT Article
AB WHILE ammonites and all other ectocochleate cephalopods became extinct, nautiloids survived relatively unchanged from the Ordovician, suggesting that they are unusually well adapted to their niche. Here we obtain high-resolution tracks of Nautilus positions and depths, combined with telemetered jet pressures, which clarify both its lifestyle and economics. Nautilus is more active in nature than in captivity1, but its energy costs are lower than projected2,3. Viewing Nautilus as 'vertic', rather than benthic, resolves this contradiction. Records show that the cost of transport is the same in any direction within a vertical plane. Living on a reef face swept by a lateral current means that vertical movements4,5 sample large areas for chemical trails. A detected trail can be followed upcurrent in the slow-moving boundary layer, but no effort is wasted on horizontal movement without good prospects for food; long-range movements are downcurrent and made by drifting. Once fed, a Nautilus can reduce its energy costs by moving to deeper, cooler waters, where a sin le meal can last for months.
C1 UNIV TEXAS,INST MARINE BIOMED,GALVESTON,TX 77555.
   UNIV CAMBRIDGE,DEPT ZOOL,CAMBRIDGE CB2 3EJ,ENGLAND.
C3 University of Texas System; University of Texas Medical Branch Galveston; University of Cambridge
RP ODOR, RK (corresponding author), DALHOUSIE UNIV,DEPT BIOL,HALIFAX B3H 4J1,NS,CANADA.
NR 10
TC 61
Z9 63
U1 1
U2 18
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 626
EP 628
DI 10.1038/362626a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800045
DA 2026-03-10
ER

PT J
AU MOORE, EDW
   ETTER, EF
   PHILIPSON, KD
   CARRINGTON, WA
   FOGARTY, KE
   LIFSHITZ, LM
   FAY, FS
AF MOORE, EDW
   ETTER, EF
   PHILIPSON, KD
   CARRINGTON, WA
   FOGARTY, KE
   LIFSHITZ, LM
   FAY, FS
TI COUPLING OF THE NA+/CA2+ EXCHANGER, NA+/K+ PUMP AND SARCOPLASMIC-RETICULUM IN SMOOTH-MUSCLE
SO NATURE
LA English
DT Article
ID sodium calcium exchange; endoplasmic-reticulum; cells; activation; release; calsequestrin; contraction; mechanism; protein
AB THE Na+/Ca2+ exchanger, driven by a transmembrane Na+ gradient, plays a key role in regulating Ca2+ concentration in many cells1,2. Although the exchanger influences Ca2+ concentration, its activity in smooth muscle appears to be closely coupled to Ca2+ availability from intracellular stores3. This linkage might result if the exchanger were positioned close to Ca2+ storage sites within the sarcoplasmic reticulum. To test this hypothesis we have developed methods to assess the relative three-dimensional distribution of proteins involved in Na+/K+ pumping, Na+/Ca2+ exchange, Ca2+ storage within the sarcoplasmic reticulum, and attachment of contractile filaments to the membrane in smooth muscle. Here we report that the Na+/Ca2+ exchanger is largely co-distributed with the Na+/K+ pump on unique regions, of the plasma membrane in register with, and close to, calsequestrin-containing regions of the sarcoplasmic reticulum in sites distinct from the sites where contractile filaments attach to the membrane. This molecular organization suggests that the plasma membrane is divided into at least two functional domains, and appear to provide a mechanism for the strong linkage seen in smooth muscle between Na+/K+ pumping and Na+/Ca2+ exchange, and between Na+/Ca2+ exchange and Ca2+ release from the sarcoplasmic reticulum4-7.
C1 UNIV MASSACHUSETTS, SCH MED, BIOMED IMAGING GRP, WORCESTER, MA 01605 USA.
   UNIV CALIF LOS ANGELES, SCH MED, DEPT MED, CARDIOVASC RES LAB, LOS ANGELES, CA 90024 USA.
   UNIV CALIF LOS ANGELES, SCH MED, DEPT PHYSIOL, CARDIOVASC RES LAB, LOS ANGELES, CA 90024 USA.
C3 University of Massachusetts System; University of Massachusetts Worcester; University of California System; University of California Los Angeles; University of California Los Angeles Medical Center; David Geffen School of Medicine at UCLA; University of California System; University of California Los Angeles; University of California Los Angeles Medical Center; David Geffen School of Medicine at UCLA
RP MOORE, EDW (corresponding author), UNIV MASSACHUSETTS, SCH MED, PROGRAM MOLEC MED, WORCESTER, MA 01605 USA.
NR 32
TC 205
Z9 222
U1 0
U2 7
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 657
EP 660
DI 10.1038/365657a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600062
PM 8413629
DA 2026-03-10
ER

PT J
AU CHEN, TY
   PENG, YW
   DHALLAN, RS
   AHAMED, B
   REED, RR
   YAU, KW
AF CHEN, TY
   PENG, YW
   DHALLAN, RS
   AHAMED, B
   REED, RR
   YAU, KW
TI A NEW SUBUNIT OF THE CYCLIC NUCLEOTIDE-GATED CATION CHANNEL IN RETINAL RODS
SO NATURE
LA English
DT Article
ID vertebrate photoreceptors; activated conductance; functional expression; ion channels; tea blockade; k+ channels; gmp; excitation; segments; calcium
AB RETINAL rods respond to light with a membrane hyperpolarization produced by a G-protein-mediated signalling cascade that leads to cyclic GMP hydrolysis and the consequent closure of a cGMP-gated channel that is open in darkness1-7. A protein that forms this channel has recently been purified from bovine retina8 and molecularly cloned9, suggesting that the native cGMP-gated channel might be a homo-oligomer10. Here we report the cloning of another protein from human retina which has only about 30% overall identity to the rod channel subunit. This protein, immunocytochemically localized to rod outer segments, does not form functional channels by itself. However, when co-expressed with the cloned human rod channel protein'', it introduces rapid flickers to the channel openings that are characteristic of the native channel12-16. The hetero-oligomeric channel is also highly sensitive to the blocker L-CiS-diltiazem, like the native channel15,17,18. This new protein thus seems to be another subunit of the native rod channel. The hetero-oligomeric nature of the rod channel means that it is no exception to a common motif shared by other ligand-gated channels.
C1 JOHNS HOPKINS UNIV, SCH MED, HOWARD HUGHES MED INST, 725 N WOLFE ST, BALTIMORE, MD 21205 USA.
   JOHNS HOPKINS UNIV, SCH MED, DEPT NEUROSCI, BALTIMORE, MD 21205 USA.
   JOHNS HOPKINS UNIV, SCH MED, DEPT BIOMED ENGN, BALTIMORE, MD 21205 USA.
   JOHNS HOPKINS UNIV, SCH MED, DEPT MOLEC BIOL & GENET, BALTIMORE, MD 21205 USA.
C3 Howard Hughes Medical Institute; Johns Hopkins University; Johns Hopkins University; Johns Hopkins University; Johns Hopkins University
NR 38
TC 306
Z9 327
U1 0
U2 3
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 764
EP 767
DI 10.1038/362764a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000061
PM 7682292
DA 2026-03-10
ER

PT J
AU NISWANDER, L
   MARTIN, GR
AF NISWANDER, L
   MARTIN, GR
TI FGF-4 AND BMP-2 HAVE OPPOSITE EFFECTS ON LIMB GROWTH
SO NATURE
LA English
DT Article
ID pattern-formation; containing genes; mouse; expression; family; embryogenesis; receptors; multiple; suggests; fetal
AB LIMB development is dependent on epithelial-mesenchymal interactions. The apical ectodermal ridge (AER), a specialized epithelium at the limb tip, stimulates proliferation of underlying mesenchyme, causing directed limb outgrowth1 (for review see ref. 2). Several genes are expressed in the mouse AER3-10, including Fgf-4 (fibroblast growth factor-4)11,12 and Bmp-2 (bone morphogenetic protein-2)13, both of which encode secreted signalling molecules. Using a culture system developed to explore the function of molecules produced by the AER, we have shown that FGF-4 protein stimulates proliferation of mesenchyme in the early mouse limb-bud. This suggests that FGF-4 serves that major function of the AER. In contrast, BMP-2 inhibits limb growth, suggesting that as a result the AER may serve a hitherto unrecognized inhibitory function. Furthermore, the extent of limb outgrowth can be modulated by mixing the two signalling molecules, suggesting that limb growth is regulated by a combination of stimulatory and inhibitory signals from the AER.
C1 UNIV CALIF SAN FRANCISCO,SCH MED,PROGRAM DEV BIOL,SAN FRANCISCO,CA 94143.
C3 University of California System; University of California San Francisco
RP NISWANDER, L (corresponding author), UNIV CALIF SAN FRANCISCO,SCH MED,DEPT ANAT,SAN FRANCISCO,CA 94143, USA.
NR 32
TC 369
Z9 411
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 68
EP 71
DI 10.1038/361068a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800050
PM 8421496
DA 2026-03-10
ER

PT J
AU BROWN, EM
   GAMBA, G
   RICCARDI, D
   LOMBARDI, M
   BUTTERS, R
   KIFOR, O
   SUN, A
   HEDIGER, MA
   LYTTON, J
   HEBERT, SC
AF BROWN, EM
   GAMBA, G
   RICCARDI, D
   LOMBARDI, M
   BUTTERS, R
   KIFOR, O
   SUN, A
   HEDIGER, MA
   LYTTON, J
   HEBERT, SC
TI CLONING AND CHARACTERIZATION OF AN EXTRACELLULAR CA2+-SENSING RECEPTOR FROM BOVINE PARATHYROID
SO NATURE
LA English
DT Article
ID metabotropic glutamate receptor; calcium concentrations; divalent-cations; xenopus oocytes; cells; sequence; expression; ca-2+; proteins; hormone
AB MAINTENANCE of a stable internal environment within complex organisms requires specialized cells that sense changes in the extracellular concentration of specific ions (such as Ca2+). Although the molecular nature of such ion sensors is unknown, parathyroid cells possess a cell surface Ca2+-sensing mechanism that also recognizes trivalent and polyvalent cations (such as neomycin) and couples by changes in phosphoinositide turnover and cytosolic Ca2+ to regulation of parathyroid hormone secretion1-4. The latter restores normocalcaemia by acting on kidney and bone2. We now report the cloning of complementary DNA encoding an extracellular Ca2+-sensing receptor from bovine parathyroid with pharmacological and functional properties nearly identical to those of the native receptor. The novel approximately 120K receptor shares limited similarity with the metabotropic glutamate receptors5 and features a large extracellular domain, containing clusters of acidic amino-acid residues possibly involved in calcium binding, coupled to a seven-membrane-spanning domain like those in the G-protein-coupled receptor superfamily.
C1 HARVARD UNIV,SCH MED,CTR STUDY KIDNEY DIS,BOSTON,MA 02115.
   BRIGHAM & WOMENS HOSP,DEPT MED,DIV RENAL,MOLEC PHYSIOL & BIOPHYS LAB,BOSTON,MA 02115.
C3 Harvard University; Harvard Medical School; Harvard University; Harvard University Medical Affiliates; Brigham & Women's Hospital
RP BROWN, EM (corresponding author), BRIGHAM & WOMENS HOSP,DEPT MED,DIV ENDOCRINE HYPERTENS,BOSTON,MA 02115, USA.
NR 30
TC 2271
Z9 2535
U1 1
U2 150
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 575
EP 580
DI 10.1038/366575a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800073
PM 8255296
DA 2026-03-10
ER

PT J
AU ROSE, GA
AF ROSE, GA
TI COD SPAWNING ON A MIGRATION HIGHWAY IN THE NORTH-WEST ATLANTIC
SO NATURE
LA English
DT Article
AB FIVE hundred years of fishing and fifty years of research have produced only vague accounts of the spawning and migrations of Atlantic cod (Gadus morhua) off Newfoundland in the north-west Atlantic1. Here I report the discovery of 'spawning columns' and a 'highway' used by cod to traverse the northeastern Newfoundland Shelf during annual springtime feeding migrations. Sea research using echosounders2,3 showed that cod spawned in dense shoals (to one fish per m3) that featured midwater spawning columns comprised of pairs of fish. Immature joined mature post-spawning cod to migrate in large (scales of tens of kilometres and hundreds of millions of fish) size-structured aggregations led by larger 'scouts'. Cod traversed the cold waters of the shelf along a deep highway of warm oceanic water (2-2.5-degrees-C). During migration, fish spacing appeared to maximize search volumes while maintaining visual contact. Aggregations fragmented when prey (capelin Mallotus villosus; shrimp, Pandalus spp.) were encountered.
RP ROSE, GA (corresponding author), FISHERIES & OCEANS CANADA,SCI BRANCH,POB 5667,ST JOHNS A1C 5X1,NF,CANADA.
NR 20
TC 299
Z9 314
U1 0
U2 32
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 458
EP 461
DI 10.1038/366458a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800062
DA 2026-03-10
ER

PT J
AU SCHINDELIN, H
   MARAHIEL, MA
   HEINEMANN, U
AF SCHINDELIN, H
   MARAHIEL, MA
   HEINEMANN, U
TI UNIVERSAL NUCLEIC ACID-BINDING DOMAIN REVEALED BY CRYSTAL-STRUCTURE OF THE BACILLUS-SUBTILIS MAJOR COLD-SHOCK PROTEIN
SO NATURE
LA English
DT Article
ID escherichia-coli; dna-binding; secondary structure; ribonucleoprotein; resolution; sequence
AB THE cold-shock response in both Escherichia coli and Bacillus subtilis is induced by an abrupt downshift in growth temperature. It leads to the increased production of the major cold-shock proteins, CS7.4 and CspB, respectively1-3. CS7.4 is a transcriptional activator of two genes4,5. CS7.4 and CspB share 43 per cent sequence identity with the nucleic acid-binding domain of the eukaryotic gene-regulatory Y-box factors6. This cold-shock domain is conserved from bacteria to man7 and contains the RNA-binding RNP1 sequence motif8. As a prototype of the cold-shock domain, the structure of CspB has been determined here from two crystal forms. In both, CspB is present as an antiparallel five-stranded beta-barrel. Three consecutive beta-strands, the central one containing the RNP1 motif, create a surface rich in aromatic and basic residues that are presumably involved in nucleic acid binding. Preferential binding of CspB to single-stranded DNA is observed in gel retardation experiments.
C1 PHILIPPS UNIV MARBURG,BIOCHEMIE FB CHEM,D-35043 MARBURG,GERMANY.
C3 Philipps University Marburg
RP SCHINDELIN, H (corresponding author), FREE UNIV BERLIN,INST KRISTALLOG,TAKUSTR 6,D-14195 BERLIN,GERMANY.
NR 30
TC 333
Z9 359
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 164
EP 168
DI 10.1038/364164a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700055
PM 8321288
DA 2026-03-10
ER

PT J
AU GROVES, AK
   BARNETT, SC
   FRANKLIN, RJM
   CRANG, AJ
   MAYER, M
   BLAKEMORE, WF
   NOBLE, M
AF GROVES, AK
   BARNETT, SC
   FRANKLIN, RJM
   CRANG, AJ
   MAYER, M
   BLAKEMORE, WF
   NOBLE, M
TI REPAIR OF DEMYELINATED LESIONS BY TRANSPLANTATION OF PURIFIED 0-2A PROGENITOR CELLS
SO NATURE
LA English
DT Article
ID rat spinal-cord; myelin-deficient rat; schwann-cells; type-1 astrocytes; growth-hormone; nervous-system; oligodendrocytes; differentiation; galactocerebroside; injection
AB THE transplantation of well defined populations of precursor cells offers a means of repairing damaged tissue and of delivering therapeutic compounds to sites of injury or degeneration. For example, a functional immune system can be reconstituted by transplantation of purified haematopoietic stem cells1, and transplanted skeletal myoblasts and keratinocytes can participate in the formation of normal tissue in host animals2-4. Cell transplantation in the central nervous system (CNS) has been proposed as a means of correcting neuronal dysfunction in diseases associated with neuronal loss5-7; it might also rectify glial cell dysfunction, with transplanted oligodendrocyte precursor cells eventually allowing repair of demyelinating damage in the CNS. Here we use co-operating growth factors to expand purified populations of oligodendrocyte type-2 astrocyte (O-2A) progenitor cells for several weeks in vitro. When injected into demyelinating lesions in spinal cords of adult rats, created in such a way as to preclude host-mediated remyelination, these expanded populations are capable of producing extensive remyelination. In addition, transplantation of O-2A progenitor cells genetically modified to express the bacterial beta-galactosidase gene gives rise to beta-galactosidase-positive oligodendrocytes which remyelinate demyelinated axons within the lesion. These results offer a viable strategy for the manipulation of neural precursor cells which is compatible with attempts to repair damaged CNS tissue by precursor transplantation.
C1 UNIV CAMBRIDGE,MRC,CAMBRIDGE CTR BRAIN REPAIR,CAMBRIDGE CB3 0ES,ENGLAND.
   LUDWIG INST CANC RES,CELLULAR NEUROBIOL LAB,LONDON W1P 8BT,ENGLAND.
   CRC BEATSON LABS,DEPT MED ONCOL & NEUROBIOL,GLASGOW G61 1BD,SCOTLAND.
   UNIV CAMBRIDGE,DEPT CLIN VET MED,CAMBRIDGE CB3 0ES,ENGLAND.
C3 University of Cambridge; Ludwig Institute for Cancer Research; Beatson Institute; University of Cambridge
FU Wellcome Trust Funding Source: Medline
NR 27
TC 326
Z9 364
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 453
EP 455
DI 10.1038/362453a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400085
PM 8464477
DA 2026-03-10
ER

PT J
AU CLARK, KL
   HALAY, ED
   LAI, ES
   BURLEY, SK
AF CLARK, KL
   HALAY, ED
   LAI, ES
   BURLEY, SK
TI CO-CRYSTAL STRUCTURE OF THE HNF-3/FORK HEAD DNA-RECOGNITION MOTIF RESEMBLES HISTONE-H5
SO NATURE
LA English
DT Article
ID gene fork-head; transcription factors; protein structures; operator complex; binding domains; trp repressor; refinement; resolution; homology; sequence
AB The three-dimensional structure of an HNF-3/fork head DNA-recognition motif complexed with DNA has been determined by X-ray crystallography at 2.5 angstrom resolution. This alpha/beta protein binds B-DNA as a monomer, through interactions with the DNA backbone and through both direct and water-mediated major and minor groove base contacts, inducing a 13-degrees bend. The transcription factor fold is very similar to the structure of histone H5. In its amino-terminal half, three alpha-helices adopt a compact structure that presents the third helix to the major groove. The remainder of the protein includes a twisted, antiparallel beta-structure and random coil that interacts with the minor groove.
C1 ROCKEFELLER UNIV, MOLEC BIOPHYS LABS, 1230 YORK AVE, NEW YORK, NY 10021 USA.
   ROCKEFELLER UNIV, HOWARD HUGHES MED INST, NEW YORK, NY 10021 USA.
   MEM SLOAN KETTERING CANC CTR, CELL BIOL & GENET PROGRAM, NEW YORK, NY 10021 USA.
   MEM SLOAN KETTERING CANC CTR, ENDOCRINOL SERV, NEW YORK, NY 10021 USA.
C3 Rockefeller University; Howard Hughes Medical Institute; Rockefeller University; Memorial Sloan Kettering Cancer Center; Memorial Sloan Kettering Cancer Center
NR 49
TC 1159
Z9 1354
U1 0
U2 57
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 412
EP 420
DI 10.1038/364412a0
PG 9
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000045
PM 8332212
DA 2026-03-10
ER

PT J
AU CHEN, CH
   DEPAOLO, DJ
   NAKADA, S
   SHIEH, YN
AF CHEN, CH
   DEPAOLO, DJ
   NAKADA, S
   SHIEH, YN
TI RELATIONSHIP BETWEEN ERUPTION VOLUME AND NEODYMIUM ISOTOPIC COMPOSITION AT UNZEN VOLCANO
SO NATURE
LA English
DT Article
ID rhyolitic magma; japan; intrusion; chambers; rocks; area
AB SILICA-rich lavas, erupted at island-arc or continental volcanoes, are often produced by a complex process involving the assimilation of crust into a crystallizing, mantle-derived basaltic magma1. The different strontium, neodymium and oxygen isotopic compositions of mantle-derived magmas and continental crust provide a powerful method for tracing the different contributions to continental silicic magmas, and for understanding the parameters controlling the composition and volume of erupted magma1-4. In the large rhyolite eruptive centres of the western United States, the largest-volume, explosive rhyolite eruptions have more mantle-like Nd isotope ratios than other silicic lavas from the same centre2-4, a relationship that has been interpreted as reflecting increased influx of mantle-derived basaltic magma to a crustal magma chamber before large-volume eruptions1. Here we report isotope data for lavas from Unzen volcano, which suggest a similar relationship: the Nd isotope composition is more mantle-like in three larger-volume dacite eruptions (>0.1 km3) than in one small-volume (0.02 km3) eruption. We accordingly suggest that, in small-volume systems like Unzen, where the timescales for magma-chamber evolution are of the order of decades, isotope data such as those presented here might be used in volcanic hazard evaluation.
C1 LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720.
   ACAD SINICA,INST EARTH SCI,TAIPEI 10764,TAIWAN.
   KYUSHU UNIV,DEPT EARTH & PLANETARY SCI,FUKUOKA 812,JAPAN.
   PURDUE UNIV,DEPT EARTH & ATMOSPHER SCI,W LAFAYETTE,IN 47907.
C3 United States Department of Energy (DOE); Lawrence Berkeley National Laboratory; Academia Sinica - Taiwan; Kyushu University; Purdue University System; Purdue University
RP CHEN, CH (corresponding author), UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,CTR ISOTOPE GEOCHEM,BERKELEY,CA 94720, USA.
NR 23
TC 28
Z9 30
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 831
EP 834
DI 10.1038/362831a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300053
DA 2026-03-10
ER

PT J
AU YAO, TP
   FORMAN, BM
   JIANG, ZY
   CHERBAS, L
   CHEN, JD
   MCKEOWN, M
   CHERBAS, P
   EVANS, RM
AF YAO, TP
   FORMAN, BM
   JIANG, ZY
   CHERBAS, L
   CHEN, JD
   MCKEOWN, M
   CHERBAS, P
   EVANS, RM
TI FUNCTIONAL ECDYSONE RECEPTOR IS THE PRODUCT OF ECR AND ULTRASPIRACLE GENES
SO NATURE
LA English
DT Article
ID retinoic acid; response elements; inducible gene; dna-binding; early puff; encodes 2; drosophila; transcription; superfamily; activation
AB ALTHOUGH the biological activity of the insect moulting hormone ecdysone, is manifested through a hormonally regulated transcriptional cascade associated with chromosomal puffing1-3, a direct association of the receptor with the puff has yet to be established. The cloned ecdysone receptor4 (EcR) is by itself incapable of high-affinity DNA binding or transcriptional activation. Rather, these activities are dependent on heterodimer formation with Ultraspiracle5 (USP) the insect homologue of vertebrate retinoid X receptor6. Here we report that native EcR and USP are co-localized on ecdysone-responsive loci of polytene chromosomes. Moreover, we show that natural ecdysones selectively promote physical association between EcR and USP, and conversely, that high-affinity hormone binding requires both EcR and USP. Replacement of USP with retinoid X receptor produces heterodimers with distinct pharmacological and functional properties. These results redefine the ecdysone receptor as a dynamic complex whose activity may be altered by combinatorial interactions among subunits and ligand.
C1 UNIV CALIF SAN DIEGO,GRAD PROGRAM BIOMED SCI,LA JOLLA,CA 92037.
   INDIANA UNIV,DEPT BIOL,BLOOMINGTON,IN 47405.
C3 University of California System; University of California San Diego; Indiana University System; Indiana University Bloomington
RP YAO, TP (corresponding author), SALK INST BIOL STUDIES,HOWARD HUGHES MED INST,LA JOLLA,CA 92037, USA.
NR 22
TC 784
Z9 926
U1 1
U2 80
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 476
EP 479
DI 10.1038/366476a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800068
PM 8247157
DA 2026-03-10
ER

PT J
AU COGNARD, I
   BOURGOIS, G
   LESTRADE, JF
   BIRAUD, F
   AUBRY, D
   DARCHY, B
   DROUHIN, JP
AF COGNARD, I
   BOURGOIS, G
   LESTRADE, JF
   BIRAUD, F
   AUBRY, D
   DARCHY, B
   DROUHIN, JP
TI AN EXTREME SCATTERING EVENT IN THE DIRECTION OF THE MILLISECOND PULSAR 1937+21
SO NATURE
LA English
DT Article
ID interstellar-medium; caustics
AB LARGE fluctuations in the radio emissions from the quasar 0954+658 (ref. 1) attest to the existence of large-scale inhomogeneities in the ionized interstellar medium. These fluctuations, termed extreme scattering events, are caused by the refractive focusing of the radio waves by discrete plasma structures. In principle, the radio emissions of pulsars should also be a sensitive probe of such phenomena2-5, which should be manifest as fluctuations in the flux density and increased delays in the timing measurements. Here we report the detection of an extreme scattering event, lasting about 15 days, in timing observations of the millisecond pulsar 1937+21. This event provides independent evidence for the existence of large-scale structure in the interstellar medium, and allows us to constrain the properties of the lensing structure (distance, velocity, linear dimension and electron density) more tightly than has been possible from detections of lensed extragalactic radio sources. Of more practical importance, such events could be the dominant source of timing noise in millisecond pulsars at approximately 1 GHz, and will need to be considered when searching for the subtle signature of gravitational waves in pulsar timing measurements.
RP COGNARD, I (corresponding author), OBSERV PARIS,F-92195 MEUDON,FRANCE.
NR 12
TC 49
Z9 52
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 320
EP 322
DI 10.1038/366320a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500040
DA 2026-03-10
ER

PT J
AU GUBBINS, D
   COE, RS
AF GUBBINS, D
   COE, RS
TI LONGITUDINALLY CONFINED GEOMAGNETIC REVERSAL PATHS FROM NONDIPOLAR TRANSITION FIELDS
SO NATURE
LA English
DT Article
AB IT has long been thought that conditions at the boundary between the core and mantle influence the Earth's magnetic field, but the supporting evidence is rather indirect1-3. Recent palaeomagnetic results, suggesting that there are persistent preferred longitudinal paths for the virtual geomagnetic pole (VGP) during reversals4, would provide the first direct evidence of the solid mantle's influence on the core, although their statistical significance has been disputed5,6. The results are potentially exciting because the preferred paths lie close to the Pacific rim, where the present geomagnetic secular variation changes character2,7. Here we present a simple model, based on an extension of a previous theory8, that produces reversals with VGP paths confined within relatively narrow longitude bands despite the transition field having a substantially non-dipolar structure. Thus, although longitude bias of the VGP paths is definitive evidence for core-mantle interaction, simple VGP paths are not evidence of near-dipolar transition fields.
C1 UNIV CALIF SANTA CRUZ,EARTH SCI BOARD,SANTA CRUZ,CA 95064.
C3 University of California System; University of California Santa Cruz
RP GUBBINS, D (corresponding author), UNIV LEEDS,DEPT EARTH SCI,LEEDS LS2 9JT,W YORKSHIRE,ENGLAND.
NR 16
TC 44
Z9 44
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 51
EP 53
DI 10.1038/362051a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600056
DA 2026-03-10
ER

PT J
AU BOMMERT, K
   CHARLTON, MP
   DEBELLO, WM
   CHIN, GJ
   BETZ, H
   AUGUSTINE, GJ
AF BOMMERT, K
   CHARLTON, MP
   DEBELLO, WM
   CHIN, GJ
   BETZ, H
   AUGUSTINE, GJ
TI INHIBITION OF NEUROTRANSMITTER RELEASE BY C2-DOMAIN PEPTIDES IMPLICATES SYNAPTOTAGMIN IN EXOCYTOSIS
SO NATURE
LA English
DT Article
ID squid giant synapse; protein kinase-c; transmitter release; binding; family; p65; dna
AB NEUROTRANSMITTER release is triggered by Ca2+ ions binding to an unknown Ca2+ receptor within presynaptic terminals1,2. Synaptotagmin, a Ca2+-binding protein of synaptic and other secretory vesicles3, has been proposed to mediate vesicle-plasma membrane interactions during neurotransmitter release4-9. Here we test this hypothesis using the giant synapse of the squid Loligo pealei, which because of its unusually large size and well established physiology is uniquely suited for dissecting presynaptic events10. We find that injection of peptides from the C2 domains of synaptotagmin into squid giant presynaptic terminals rapidly and reversibly inhibits neurotransmitter release. Our data are consistent with these peptides competitively blocking release after synaptic vesicle docking and indicate that Ca2+ probably initiates neurotransmitter release by regulating the interaction of synaptotagmin with an acceptor protein.
C1 MAX PLANCK INST BRAIN RES,DEPT NEUROCHEM,W-6000 FRANKFURT 71,GERMANY.
   UNIV TORONTO,DEPT PHYSIOL,TORONTO M5S 1A8,ONTARIO,CANADA.
   DUKE UNIV,MED CTR,DEPT NEUROBIOL,DURHAM,NC 27710.
   NIH,DEV NEUROBIOL LAB,BETHESDA,MD 20892.
C3 Max Planck Society; University of Toronto; Duke University; National Institutes of Health (NIH) - USA
RP BOMMERT, K (corresponding author), MARINE BIOL LAB,WOODS HOLE,MA 02543, USA.
NR 31
TC 284
Z9 298
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 163
EP 165
DI 10.1038/363163a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100048
PM 8097867
DA 2026-03-10
ER

PT J
AU VLATAKIS, G
   ANDERSSON, LI
   MULLER, R
   MOSBACH, K
AF VLATAKIS, G
   ANDERSSON, LI
   MULLER, R
   MOSBACH, K
TI DRUG ASSAY USING ANTIBODY MIMICS MADE BY MOLECULAR IMPRINTING
SO NATURE
LA English
DT Article
ID performance liquid-chromatography; amino-acid derivatives; enzyme-immunoassay; enantiomeric resolution; polymers; theophylline; recognition; serum; specificity; noncovalent
AB LIGAND-BINDING assays are used for determination of minute amounts of substances in the bloodstream. Such assays require a receptor that specifically binds the substance of interest. The receptor used is often an antibody1-5, but antibodies require special handling and a costly production procedure5. We have used molecular imprinting, a method for creating selective recognition sites in synthetic polymers6-8, to prepare polymers that mimic antibody combining sites. Molecular imprints made against theophylline9 and diazepam10 showed strong binding and cross-reactivity profiles similar to those of antibodies. Here we describe a new radiolabelled ligand-binding assay, the molecularly imprinted sorbent assay, which uses antibody mimics. This assay accurately measures drug levels in human serum, with results comparable to those obtained using a well established immunoassay technique. Antibody mimics, which are stable and readily prepared by molecular imprinting, may provide a useful general alternative to antibodies.
C1 UNIV LUND,CTR CHEM,DEPT PURE & APPL BIOCHEM,POB 124,S-22100 LUND,SWEDEN.
C3 Lund University
NR 30
TC 1602
Z9 1846
U1 7
U2 801
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 645
EP 647
DI 10.1038/361645a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600066
PM 8437624
DA 2026-03-10
ER

PT J
AU WHITE, RE
   LEE, AB
   SHCHERBATKO, AD
   LINCOLN, TM
   SCHONBRUNN, A
   ARMSTRONG, DL
AF WHITE, RE
   LEE, AB
   SHCHERBATKO, AD
   LINCOLN, TM
   SCHONBRUNN, A
   ARMSTRONG, DL
TI POTASSIUM CHANNEL STIMULATION BY NATRIURETIC PEPTIDES THROUGH CGMP-DEPENDENT DEPHOSPHORYLATION
SO NATURE
LA English
DT Article
ID ca-2+-activated k+ channels; anterior-pituitary-cells; smooth-muscle cells; protein-kinase; calcium channels; cyclic-gmp; modulation; phosphatases; receptor; cyclase
AB NATRIURETIC peptides inhibit the release and action of many hormones through cyclic guanosine monophosphate (cGMp)1,2, but the mechanism of cGMP action is unclear3. In frog ventricular muscle and guinea-pig hippocampal neurons, cGMP inhibits voltage-activated Ca2+ currents by stimulating phosphodiesterase activity and reducing intracellular cyclic AMP4,5; however, this mechanism is not involved in the action of cGMP on other channels6 or on Ca2+ channels in other cells7,8. Natriuretic peptide receptors in the rat pituitary also stimulate guanylyl cyclase activity but inhibit secretion by increasing membrane conductance to potassium9,10. In an electrophysiological study on rat pituitary tumour cells11, we identified the large-conductance, calcium- and voltage-activated potassium channels (BK) as the primary target of another inhibitory neuropeptide, somatostatin. Here we report that atrial natriuretic peptide also stimulates BK channel activity in GH4C1 cells through protein dephosphorylation. Unlike somatostatin, however, the effect of atrial natriuretic peptide on BK channel activity is preceded by a rapid and potent stimulation of cGMP production and requires cGMP-dependent protein kinase activity. Protein phosphatase activation by cGMP-dependent kinase could explain the inhibitory effects of natriuretic peptides on electrical excitability and the antagonism of cGMP and cAMP in many systems12.
C1 NIEHS, CELLULAR & MOLEC PHARMACOL LAB, RES TRIANGLE PK, NC 27709 USA.
   UNIV ALABAMA, DEPT PATHOL, BIRMINGHAM, AL 35294 USA.
   UNIV TEXAS, SCH MED, DEPT PHARMACOL, HOUSTON, TX 77225 USA.
C3 National Institutes of Health (NIH) - USA; NIH National Institute of Environmental Health Sciences (NIEHS); University of Alabama System; University of Alabama Birmingham; University of Texas System
NR 31
TC 242
Z9 263
U1 0
U2 5
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 263
EP 266
DI 10.1038/361263a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400061
PM 7678699
DA 2026-03-10
ER

PT J
AU WEISSKOPF, MG
   ZALUTSKY, RA
   NICOLL, RA
AF WEISSKOPF, MG
   ZALUTSKY, RA
   NICOLL, RA
TI THE OPIOID PEPTIDE DYNORPHIN MEDIATES HETEROSYNAPTIC DEPRESSION OF HIPPOCAMPAL MOSSY FIBER SYNAPSES AND MODULATES LONG-TERM POTENTIATION
SO NATURE
LA English
DT Article
ID ca3 pyramidal cells; guinea-pig; rat hippocampus; n-type; calcium channels; dentate gyrus; binding-sites; paired-pulse; receptor; neurons
AB The mossy fibre pathway in the hippocampus uses glutamate as a neurotransmitter, but also contains the opioid peptide dynorphin. Synaptic release of dynorphin causes a presynaptic inhibition of neighbouring mossy fibres and inhibits the induction and expression of mossy fibre long-term potentiation. These findings demonstrate a physiological role for a neuropeptide in the central nervous system, provide a functional basis for the coexistence of a neuropeptide with classic neurotransmitters and demonstrate the very different roles played by these two classes of signalling molecules.
C1 UNIV CALIF SAN FRANCISCO, GRAD PROGRAM NEUROSCI, SAN FRANCISCO, CA 94143 USA.
   UNIV CALIF SAN FRANCISCO, DEPT PHARMACOL, SAN FRANCISCO, CA 94143 USA.
   UNIV CALIF SAN FRANCISCO, DEPT PHYSIOL, SAN FRANCISCO, CA 94143 USA.
C3 University of California System; University of California San Francisco; University of California System; University of California San Francisco; University of California System; University of California San Francisco
NR 49
TC 255
Z9 272
U1 0
U2 3
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 423
EP 427
DI 10.1038/362423a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400074
PM 8096624
DA 2026-03-10
ER

PT J
AU HORN, RG
   SMITH, DT
   GRABBE, A
AF HORN, RG
   SMITH, DT
   GRABBE, A
TI CONTACT ELECTRIFICATION INDUCED BY MONOLAYER MODIFICATION OF A SURFACE AND RELATION TO ACID-BASE INTERACTIONS
SO NATURE
LA English
DT Article
ID forces
AB ELECTRICAL charge separation following contact between two materials (contact electrification or the triboelectric effect) is well known to occur between different materials as a consequence of their different electronic structures1,2. Here we show that the phenomenon occurs between two surfaces of the same material if one is coated with a single chemisorbed monolayer. We use the surface force apparatus3 to study contact electrification4 and adhesion between two silica surfaces, one coated with an amino-silane. The presence of this monolayer results in significantly enhanced adhesion between the surfaces, owing to electrostatic attraction following contact electrification, in accord with Derjaguin's electrostatic theory of adhesion5. At the same time, the observed increase in adhesion is consistent with Fowkes' acid-base model6 (in which acid-base interactions between surface groups are considered to be the predominant factor determining adhesion), as the monolayer converts the originally acidic silica surface to a basic (amine-terminated) one. These observations demonstrate a link between acid-base interactions and contact electrification.
C1 NATL STANDARDS & TECHNOL,DIV CERAM,GAITHERSBURG,MD 20899.
C3 National Institute of Standards & Technology (NIST) - USA
NR 13
TC 193
Z9 214
U1 2
U2 112
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 442
EP 443
DI 10.1038/366442a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800056
DA 2026-03-10
ER

PT J
AU LILLEY, MD
   BUTTERFIELD, DA
   OLSON, EJ
   LUPTON, JE
   MACKO, SA
   MCDUFF, RE
AF LILLEY, MD
   BUTTERFIELD, DA
   OLSON, EJ
   LUPTON, JE
   MACKO, SA
   MCDUFF, RE
TI ANOMALOUS CH4 AND NH4+ CONCENTRATIONS AT AN UNSEDIMENTED MID-OCEAN-RIDGE HYDROTHERMAL SYSTEM
SO NATURE
LA English
DT Article
ID de-fuca-ridge; massive sulfides; guaymas basin; vent field; fluids; geochemistry; chemistry; methane; juan; origins
AB SINCE the discovery in 1977 of sea-floor hydrothermal systems, the study of the chemistry of the venting fluids has transformed our understanding of the geochemical cycles that influence the composition of sea water and the ocean crust. With few exceptions (Guaymas basin being the most notable), the vent systems studied so far are free of sedimentary influence and the chemistry of the fluids can be explained on the basis of interactions between sea water and basalt. Such fluids typically contain low methane concentrations, ranging from 50 to 120 muM (refs 1-7), and ammonium concentrations less than 10 muM (ref. 8). Here we report CH4 and NH4+ concentrations from the Endeavour segment of the Juan de Fuca Ridge which are many times greater than those measured previously at any unsedimented mid-ocean ridge. The C-13/C-12 ratio of this CH4 is the lowest yet found in any hydrothermal environment, implying an unusual source. We attribute these high CH4 and NH4+ concentrations to the decomposition of sub-sea-floor organic matter associated with sediments buried at an earlier stage of the ridge's evolution. These data illustrate that the organic geochemistry of unsedimented ridges may be more complex than suspected hitherto.
C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115.
   NOAA,PACIFIC MARINE ENVIRONM LAB,HATFIELD MARINE SCI CTR,NEWPORT,OR 97365.
   UNIV VIRGINIA,DEPT ENVIRONM SCI,CHARLOTTESVILLE,VA 22903.
C3 National Oceanic Atmospheric Admin (NOAA) - USA; National Oceanic Atmospheric Admin (NOAA) - USA; University of Virginia
RP LILLEY, MD (corresponding author), UNIV WASHINGTON,SCH OCEANOG WB-10,SEATTLE,WA 98195, USA.
NR 32
TC 275
Z9 297
U1 0
U2 55
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 45
EP 47
DI 10.1038/364045a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800051
DA 2026-03-10
ER

PT J
AU SUKUMAR, R
   RAMESH, R
   PANT, RK
   RAJAGOPALAN, G
AF SUKUMAR, R
   RAMESH, R
   PANT, RK
   RAJAGOPALAN, G
TI A DELTA-C-13 RECORD OF LATE QUATERNARY CLIMATE-CHANGE FROM TROPICAL PEATS IN SOUTHERN INDIA
SO NATURE
LA English
DT Article
ID carbon isotope discrimination; ice-age; holocene; ratios; calibration; plants; pollen; kenya
AB STABLE-ISOTOPE ratios of carbon in soils or lake sediments1-3 and of oxygen and hydrogen in peats4,5 have been found to reflect past moisture variations and hence to provide valuable palaeoclimate records. Previous applications of the technique to peat have been restricted to temperate regions, largely because tropical climate variations are less pronounced, making them harder to resolve. Here we present a deltaC-13 record spanning the past 20 kyr from peats in the Nilgiri hills, southern India. Because the site is at high altitude (>2,000 m above sea level), it is possible to resolve a clear climate signal. We observe the key climate shifts that are already known to have occurred during the last glacial maximum (18 kyr ago) and the subsequent deglaciation. In addition, we observe an arid phase from 6 to 3.5 kyr ago, and a short, wet phase about 600 years ago. The latter appears to correspond to the Mediaeval Warm Period, which previously was believed to be confined to Europe and North America6,7. Our results therefore suggest that this event may have extended over the entire Northern Hemisphere.
C1 PHYS RES LAB,AHMEDABAD 380009,GUJARAT,INDIA.
   BIRBAL SAHNI INST PALEOBOT,LUCKNOW 226007,INDIA.
C3 Department of Space (DoS), Government of India; Physical Research Laboratory - India; Department of Science & Technology (India); Birbal Sahni Institute of Palaeobotany (BSIP)
RP SUKUMAR, R (corresponding author), INDIAN INST SCI,CTR ECOL SCI,BANGALORE 560012,KARNATAKA,INDIA.
NR 31
TC 231
Z9 270
U1 0
U2 34
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 703
EP 706
DI 10.1038/364703a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700052
DA 2026-03-10
ER

PT J
AU NOWAK, M
   SIGMUND, K
AF NOWAK, M
   SIGMUND, K
TI A STRATEGY OF WIN STAY, LOSE SHIFT THAT OUTPERFORMS TIT-FOR-TAT IN THE PRISONERS-DILEMMA GAME
SO NATURE
LA English
DT Article
ID evolution; cooperation
AB THE Prisoner's Dilemma is the leading metaphor for the evolution of cooperative behaviour in populations of selfish agents, especially since the well-known computer tournaments of Axelrod1 and their application to biological communities2,3. In Axelrod's simulations, the simple strategy tit-for-tat did outstandingly well and subsequently became the major paradigm for reciprocal altruism4-12. Here we present extended evolutionary simulations of heterogeneous ensembles of probabilistic strategies including mutation and selection, and report the unexpected success of another protagonist: Pavlov. This strategy is as simple as tit-for-tat and embodies the fundamental behavioural mechanism win-stay, lose-shift, which seems to be a widespread rule13. Pavlov's success is based on two important advantages over tit-for-tat: it can correct occasional mistakes and exploit unconditional cooperators. This second feature prevents Pavlov populations from being undermined by unconditional cooperators, which in turn invite defectors. Pavlov seems to be more robust than tit-for-tat, suggesting that cooperative behaviour in natural situations may often be based on win-stay, lose-shift.
C1 UNIV VIENNA, INST MATH, A-1090 VIENNA, AUSTRIA.
C3 University of Vienna
RP NOWAK, M (corresponding author), UNIV OXFORD, DEPT ZOOL, S PARKS RD, OXFORD OX1 3PS, ENGLAND.
NR 27
TC 1268
Z9 1444
U1 3
U2 253
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 56
EP 58
DI 10.1038/364056a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800055
PM 8316296
DA 2026-03-10
ER

PT J
AU HANNA, S
   ROMOURIBE, A
   WINDLE, AH
AF HANNA, S
   ROMOURIBE, A
   WINDLE, AH
TI SEQUENCE SEGREGATION IN MOLTEN LIQUID-CRYSTALLINE RANDOM COPOLYMERS
SO NATURE
LA English
DT Article
ID 2-hydroxy-6-naphthoic acid; 4-hydroxybenzoic acid; chain; transesterification; diffraction; randomization; copolyesters; temperature; polymer; order
AB THE polymerization of two or more types of monomer to form random copolymer molecules yields commercially important thermotropic liquid-crystalline polymeric materials1. The limited degree of crystallization observed for these random copolymers is thought to occur through a process of segregation: random but similar sequences of the different monomer units on adjacent chains come into register to form a layered structure with crystalline periodicity perpendicular to the chain axes but with aperiodicity parallel to the chains, giving 'non-periodic layer' crystals2,3. If, as has been believed, the melt is a nematic liquid crystal4, the question of how the necessary large-scale molecular rearrangements can occur even when crystallization is rapid is puzzling. Here we report the results of a wide-angle X-ray scattering study of a series of oriented molten samples of a class of these materials known as B-N random copolymers, which show that segregated, layered structures are already present in the melt. In other words, the melt contains smectic-type regions within a nematic matrix. The presence of these regions of sequence matching opens up the possibility of controlling the microstructure, and thus the properties, of thermoplastics through the introduction of specifically synthesized non-random sequences into the molecular chains.
RP HANNA, S (corresponding author), UNIV CAMBRIDGE,DEPT MAT SCI & MET,PEMBROKE ST,CAMBRIDGE CB2 3QZ,ENGLAND.
NR 26
TC 69
Z9 70
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 546
EP 549
DI 10.1038/366546a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800063
DA 2026-03-10
ER

PT J
AU DUTTA, A
   RUPPERT, JM
   ASTER, JC
   WINCHESTER, E
AF DUTTA, A
   RUPPERT, JM
   ASTER, JC
   WINCHESTER, E
TI INHIBITION OF DNA-REPLICATION FACTOR RPA BY P53
SO NATURE
LA English
DT Article
ID protein-a; sv40 origin; t-antigen; invitro; binding; initiation; mutations; subunit; gene
AB THE tumour suppressor p53 specifically interferes with the onset of S phase. The mechanism of the growth suppression action of the protein is unclear, though recent evidence points to transcriptional activation and repression functions of the protein1. A competing hypothesis suggests that p53 interacts with the DNA replication apparatus and directly interferes with DNA replication. The major evidence for this hypothesis is that p53 interacts with the simian virus 40 (SV40)-encoded protein T antigen and interferes with the ability of T antigen to unwind the SV40 origin of DNA replication, and recruit DNA polymerase alpha to the replication initiation complex2,3. Here we report that p53 physically interacts with and inhibits the function of a cellular DNA replication factor, the single-stranded DNA-binding protein complex RPA.
C1 JOHNS HOPKINS UNIV,SCH MED,DEPT OTOLARYNGOL & HEAD & NECK SURG,BALTIMORE,MD 21205.
C3 Johns Hopkins University
RP DUTTA, A (corresponding author), HARVARD UNIV,BRIGHAM & WOMENS HOSP,SCH MED,DEPT PATHOL,DIV MOLEC ONCOL,20 SHATTUCK ST,BOSTON,MA 02115, USA.
NR 22
TC 386
Z9 411
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 79
EP 82
DI 10.1038/365079a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600059
PM 8361542
DA 2026-03-10
ER

PT J
AU KAHL, JD
   CHARLEVOIX, DJ
   ZAITSEVA, NA
   SCHNELL, RC
   SERREZE, MC
AF KAHL, JD
   CHARLEVOIX, DJ
   ZAITSEVA, NA
   SCHNELL, RC
   SERREZE, MC
TI ABSENCE OF EVIDENCE FOR GREENHOUSE WARMING OVER THE ARCTIC-OCEAN IN THE PAST 40 YEARS
SO NATURE
LA English
DT Article
ID temperature; troposphere; climate; stratosphere; variability; trends; space
AB ATMOSPHERIC general circulation models predict enhanced greenhouse warming at high latitudes1 owing to positive feedbacks between air temperature, ice extent and surface albedo2-4. Previous analyses of Arctic temperature trends have been restricted to land-based measurements on the periphery of the Arctic Ocean5,6. Here we present temperatures measured in the lower troposphere over the Arctic Ocean during the period 1950-90. We have analysed more than 27,000 temperature profiles, measured by radiosonde at Russian drifting ice stations and by dropsonde from US 'Ptarmigan' weather reconnaissance aircraft, for trends as a function of season and altitude. Most of the trends are not statistically significant. In particular, we do not observe the large surface warming trends predicted by models; indeed, we detect significant surface cooling trends over the western Arctic Ocean during winter and autumn. This discrepancy suggests that present climate models do not adequately incorporate the physical processes that affect the polar regions.
C1 STATE COMM HYDROMETEOROL,CENT AEROL OBSERV,DOLGOPRUDNYI 141700,RUSSIA.
   NOAA,CLIMATE MONITORING & DIAGNOST LAB,MAUNA LOA OBSERV,HILO,HI 96721.
   UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,DIV CRYOSPHER & POLAR PROC,BOULDER,CO 80309.
C3 National Oceanic Atmospheric Admin (NOAA) - USA; University of Colorado System; University of Colorado Boulder; National Oceanic Atmospheric Admin (NOAA) - USA
RP KAHL, JD (corresponding author), UNIV WISCONSIN,DEPT GEOSCI,POB 413,MILWAUKEE,WI 53201, USA.
NR 22
TC 93
Z9 96
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 335
EP 337
DI 10.1038/361335a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000050
DA 2026-03-10
ER

PT J
AU ZHAO, WJ
   NELSON, KD
AF ZHAO, WJ
   NELSON, KD
TI DEEP SEISMIC-REFLECTION EVIDENCE FOR CONTINENTAL UNDERTHRUSTING BENEATH SOUTHERN TIBET
SO NATURE
LA English
DT Article
ID eastern nepal himalaya; collision; constraints; plateau
AB THE Himalaya and adjacent Tibetan plateau, constituting Earth's largest region of elevated topography and anomalously thick crust, formed as a consequence of Cenozoic collision between India and Asia-itself considered the archetypal continent-continent collision1-3. Here we report the first results from an attempt to image the structure of the crust beneath this region using deep seismic reflection profiling. Our approximately 100-km-long profile, acquired in the Tethyan Himalaya, shows a mid-crustal reflection that probably marks the active thrust fault along which the Indian plate is underthrusting southern Tibet; upper-crustal reflections with geometries suggestive of large-scale structural imbrication of the upper crust; and Moho reflections from the base of the double-normal-thickness crust underlying the region. These results lend substantial support to the view that crustal thickening beneath southernmost Tibet was accomplished by wholesale underthrusting of Indian continental crust beneath the structurally imbricated upper crust comprising the Tethyan Himalaya.
C1 SYRACUSE UNIV,DEPT GEOL,SYRACUSE,NY 13244.
C3 Syracuse University
RP ZHAO, WJ (corresponding author), CHINESE ACAD GEOL SCI,MINIST GEOL & MINERAL RESOURCES,BEIJING,PEOPLES R CHINA.
NR 16
TC 672
Z9 867
U1 2
U2 111
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 557
EP 559
DI 10.1038/366557a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800067
DA 2026-03-10
ER

PT J
AU DRATZ, EA
   FURSTENAU, JE
   LAMBERT, CG
   THIREAULT, DL
   RARICK, H
   SCHEPERS, T
   PAKHLEVANIANTS, S
   HAMM, HE
AF DRATZ, EA
   FURSTENAU, JE
   LAMBERT, CG
   THIREAULT, DL
   RARICK, H
   SCHEPERS, T
   PAKHLEVANIANTS, S
   HAMM, HE
TI NMR STRUCTURE OF A RECEPTOR-BOUND G-PROTEIN PEPTIDE
SO NATURE
LA English
DT Article
ID signal transduction; pertussis toxin; alpha-subunit; binding; determinants; mutation
AB HETEROTRIMERIC GTP-binding proteins (G proteins) regulate cellular activity by coupling to hormone or sensory receptors. Stimulated receptors catalyse the release of GDP from G protein alpha-subunits1-4 and GTP bound to the empty alpha-subunits provides signals that control effectors such as adenylyl cyclases, phosphodiesterases, phospholipases and ion channels4. Three cytoplasmic loops of the activated receptor are thought to interact with three sites on the heterotrimeric G protein to provide high-affinity interaction and catalyse G-protein activation5-8. The carboxyl terminus of the alpha-subunit is particularly important for interaction with the receptor9-14. Here we study the structure of part of the active interface between the photon receptor rhodopsin and the G protein transducin, or G(t), using nuclear magnetic resonance. An 11-amino-acid peptide from the C terminus of the alpha-subunit of G(t) (alpha(t) (340-350)) binds to rhodopsin and mimics the G protein in stabilizing its active form, metarhodopsin II. The peptide alpha(t) (340-350) binds to both excited and unexcited rhodopsin and conformational differences between the two bound forms suggest a mechanism for activation of G proteins by agonist-stimulated receptors. Insight into receptor-catalysed GDP release will have broad application because the GTP/GDP exchange and the intrinsic GTPase activity of GTP-binding proteins constitute a widespread regulatory mechanism15.
C1 UNIV ILLINOIS, COLL MED, DEPT PHYSIOL & BIOPHYS, CHICAGO, IL 60680 USA.
   UNIV ILLINOIS, COLL MED, DEPT OPHTHALMOL, CHICAGO, IL 60680 USA.
   UNIV SASSARI, IST FISIOL GEN & CHIM BIOL, I-07100 SASSARI, ITALY.
C3 University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital; University of Illinois System; University of Illinois Chicago; University of Illinois Chicago Hospital; University of Sassari
RP DRATZ, EA (corresponding author), MONTANA STATE UNIV, DEPT CHEM & BIOCHEM, BOZEMAN, MT 59717 USA.
NR 33
TC 163
Z9 176
U1 0
U2 6
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 276
EP 281
DI 10.1038/363276a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600057
PM 8487866
DA 2026-03-10
ER

PT J
AU HAMMER, M
AF HAMMER, M
TI AN IDENTIFIED NEURON MEDIATES THE UNCONDITIONED STIMULUS IN ASSOCIATIVE OLFACTORY LEARNING IN HONEYBEES
SO NATURE
LA English
DT Article
ID apis-mellifera; mushroom body; term-memory; bee; mutants; brain; gene
AB DURING classical conditioning, animals learn to associate a neutral stimulus with a meaningful, or unconditioned, stimulus. The unconditioned stimulus is essential for forming associations, and modifications in the processing of the unconditioned stimulus are thought to underlie more complex learning forms1-4. Information on the neuronal representation of the unconditioned stimulus is therefore required for understanding both basic and higher-order features of conditioning. In honeybees, conditioning of the proboscis extension reflex occurs after a single pairing of an odour (conditioned stimulus) with food (unconditioned stimulus)5,6 and shows several higher-order features of conditioning6-8.  I report here the identification of an interneuron that mediates the unconditioned stimulus in this associative learning. Its physiology is also compatible with a function in complex forms of associative learning. This neuron provides the first direct access to the cellular mechanisms underlying the reinforcing properties of the unconditioned stimulus pathway.
RP HAMMER, M (corresponding author), FREE UNIV BERLIN,INST NEUROBIOL,KONIGIN LUISE STR 28-30,D-14195 BERLIN,GERMANY.
NR 25
TC 508
Z9 548
U1 1
U2 65
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 59
EP 63
DI 10.1038/366059a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700053
PM 24308080
DA 2026-03-10
ER

PT J
AU RUEL, L
   BOUROUIS, M
   HEITZLER, P
   PANTESCO, V
   SIMPSON, P
AF RUEL, L
   BOUROUIS, M
   HEITZLER, P
   PANTESCO, V
   SIMPSON, P
TI DROSOPHILA SHAGGY KINASE AND RAT GLYCOGEN-SYNTHASE KINASE-3 HAVE CONSERVED ACTIVITIES AND ACT DOWNSTREAM OF NOTCH
SO NATURE
LA English
DT Article
ID proneural clusters; gene; protein; expression; product; homolog; locus; sequence; repeats; cells
AB DURING neurogenesis in Drosophila, groups of equipotential, neurally competent cells choose between epidermal and neural fates1-4. Notch, a phylogenetically conserved transmembrane protein5-9, may act as a receptor4,10 in a lateral signalling pathway in which a single neural precursor is chosen from each group and the neural fate of the other cells is inhibited, causing them to differentiate into epidermis11-13.  Possible intracellular trans duction events mediating signals from Notch are, however, unknown. shaggy is also required for the lateral signal4,14  and encodes serine/threonine protein kinases15,16 with homology to the glycogen synthase kinase-3 (GSK-3) enzymes17 that act in signal transduction pathways in vertebrates17. We report here that, in transgenic flies, GSK-3beta can substitute for shaggy, and we also present a study of epistatic relationships between shaggy and gain and loss of function alleles of Notch. The results indicate that shaggy/GSK-3 is part of a signalling pathway downstream of Notch.
C1 FAC MED STRASBOURG,CNRS,GENET MOLEC EUCARYOTES LAB,INSERM,U184,F-67085 STRASBOURG,FRANCE.
C3 Universites de Strasbourg Etablissements Associes; Universite de Strasbourg; Centre National de la Recherche Scientifique (CNRS); Institut National de la Sante et de la Recherche Medicale (Inserm)
NR 28
TC 188
Z9 198
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 557
EP 560
DI 10.1038/362557a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300059
PM 8385271
DA 2026-03-10
ER

PT J
AU ELIOT, LS
   KANDEL, ER
   SIEGELBAUM, SA
   BLUMENFELD, H
AF ELIOT, LS
   KANDEL, ER
   SIEGELBAUM, SA
   BLUMENFELD, H
TI IMAGING TERMINALS OF APLYSIA SENSORY NEURONS DEMONSTRATES ROLE OF ENHANCED CA2+ INFLUX IN PRESYNAPTIC FACILITATION
SO NATURE
LA English
DT Article
ID long-term potentiation; gill-withdrawal reflex; behavioral sensitization; transmitter release; synaptic transmission; calcium; modulation; mechanism; serotonin; channels
AB MODULATION of transmitter release underlies several forms of learning-related synaptic plasticity, including presynaptic facilitation and long-term potentiation1-4. Although the presynaptic terminals of most neurons are not accessible for direct study, it has often been possible to correlate changes in calcium influx in the cell body, owing to modulation of K+ or Ca2+ channels, with changes in release5-7. Some forms of presynaptic plasticity, however, do not involve changes in Ca2+ influx8-12. Moreover, the presence of multiple types of K+ and Ca2+ channels with different subcellular distributions makes the direct measurement of Ca2+ influx into presynaptic terminals essential. Using synapses reconstituted in culture between Aplysia sensory and motor neurons13, we have imaged Ca2+ influx in presynaptic terminal regions in response to action potentials, and demonstrate that presynaptic facilitation produced by 5-hydroxytryptamine involves enhanced Ca2+ influx through dihydropyridine (DHP)-insensitive Ca2+ channels14 present near release sites. This increased influx is attributable to spike broadening and is significantly correlated with the magnitude of presynaptic facilitation. By contrast, DHP-sensitive channels appear to aid the recovery from depression due to high-frequency stimulation.
C1 COLUMBIA UNIV COLL PHYS & SURG,CTR NEUROL & BEHAV,722 W 168TH ST,NEW YORK,NY 10032.
   HOWARD HUGHES MED INST,NEW YORK,NY 10032.
C3 Columbia University; Howard Hughes Medical Institute
NR 30
TC 66
Z9 72
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 634
EP 637
DI 10.1038/361634a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600063
PM 8382344
DA 2026-03-10
ER

PT J
AU DAVIES, K
AF DAVIES, K
TI CLONING THE MENKES DISEASE GENE
SO NATURE
LA English
DT Article
NR 9
TC 13
Z9 14
U1 1
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 98
EP 98
DI 10.1038/361098a0
PG 1
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800059
PM 8421503
DA 2026-03-10
ER

PT J
AU THOMSON, RC
   MACKAY, CD
   WRIGHT, AE
AF THOMSON, RC
   MACKAY, CD
   WRIGHT, AE
TI INTERNAL STRUCTURE AND POLARIZATION OF THE OPTICAL JET OF THE QUASAR-3C273
SO NATURE
LA English
DT Article
ID 3c-273; 3c273; deconvolution; images; light
AB THE extragalactic radio source 3C273 was the first quasar to be identified1, and remains one of the nearest and most luminous quasars known. In radio images2-4, it appears as a bright, point-like nucleus from which emerges a single large jet; the jet is also apparent in optical images5-8, but the relatively poor resolution of ground-based optical data has hampered detailed comparisons with the radio maps. Here we present high-resolution intensity and polarization maps of the optical jet of 3C273 obtained using the Faint Object Camera on the Hubble Space Telescope. The optical emission is tightly confined to the core of the radio jet, and is resolved into a number of highly polarized knot structures. Both the optical and radio emission can be explained by synchrotron radiation from a stream of energetic particles burrowing into the surrounding medium. Comparison with the radio maps also reveals asymmetry in the emission across the jet, indicating significant lateral motion of the jet relative to the ambient medium. The onset of optical emission from the jet some distance from the nucleus of 3C273 could arise from the interaction of the jet with a shell of gaseous material surrounding the host galaxy.
C1 AUSTRALIA TELESCOPE NATL FACIL,PARKES,NSW 2870,AUSTRALIA.
C3 Commonwealth Scientific & Industrial Research Organisation (CSIRO); Australia Telescope National Facility
RP THOMSON, RC (corresponding author), UNIV CAMBRIDGE,INST ASTRON,MADINGLEY RD,CAMBRIDGE CB3 0HA,ENGLAND.
NR 23
TC 55
Z9 57
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 133
EP 135
DI 10.1038/365133a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200039
DA 2026-03-10
ER

PT J
AU OLIET, SHR
   BOURQUE, CW
AF OLIET, SHR
   BOURQUE, CW
TI MECHANOSENSITIVE CHANNELS TRANSDUCE OSMOSENSITIVITY IN SUPRAOPTIC NEURONS
SO NATURE
LA English
DT Article
ID ion channels; rat; vasopressin; oxytocin; activation; nucleus; stimuli
AB VASOPRESSIN is a peptide hormone synthesized by neurons of the supraoptic and paraventricular nuclei, which project axon terminals to the neurohypophysis. Consistent with its antidiuretic properties, vasopressin release rises as a function of plasma osmolality1-3, a response that results from accelerated action potential discharge4-6. Previous studies have shown that increases in fluid osmolality depolarize supraoptic neurons in the absence of synaptic transmission7-9, suggesting that these cells behave as intrinsic osmoreceptors. The mechanism by which changes in osmolality are transduced into an electrical signal is unknown, however. Here we report that changes in cell volume accompany physiological variations in fluid osmolality and that these modulate the activity of mechanosensitive cation channels in a way that is consistent with the macroscopic regulation of membrane voltage and action potential discharge. These findings define a function for stretch-inactivated channels in mammalian central neurons.
C1 MONTREAL GEN HOSP,CTR RES NEUROSCI,1650 CEDAR AVE,MONTREAL H3G 1A4,QUEBEC,CANADA.
   MCGILL UNIV,MONTREAL H3G 1A4,PQ,CANADA.
C3 McGill University; McGill University
NR 19
TC 287
Z9 317
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 341
EP 343
DI 10.1038/364341a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000058
PM 7687327
DA 2026-03-10
ER

PT J
AU VONITZSTEIN, M
   WU, WY
   KOK, GB
   PEGG, MS
   DYASON, JC
   JIN, B
   PHAN, TV
   SMYTHE, ML
   WHITE, HF
   OLIVER, SW
   COLMAN, PM
   VARGHESE, JN
   RYAN, DM
   WOODS, JM
   BETHELL, RC
   HOTHAM, VJ
   CAMERON, JM
   PENN, CR
AF VONITZSTEIN, M
   WU, WY
   KOK, GB
   PEGG, MS
   DYASON, JC
   JIN, B
   PHAN, TV
   SMYTHE, ML
   WHITE, HF
   OLIVER, SW
   COLMAN, PM
   VARGHESE, JN
   RYAN, DM
   WOODS, JM
   BETHELL, RC
   HOTHAM, VJ
   CAMERON, JM
   PENN, CR
TI RATIONAL DESIGN OF POTENT SIALIDASE-BASED INHIBITORS OF INFLUENZA-VIRUS REPLICATION
SO NATURE
LA English
DT Article
ID 2-deoxy-2,3-dehydro-n-acetylneuraminic acid; binding-sites; neuraminidase; resolution; hemagglutinin; glycoprotein; assay
AB Two potent inhibitors based on the crystal structure of influenza virus sialidase have been designed. These compounds are effective inhibitors not only of the enzyme, but also of the virus In cell culture and in animal models. The results provide an example of the power of rational, computer-assisted drug design, as well as indicating significant progress in the development of a new therapeutic or prophylactic treatment for influenza infection.
C1 CSIRO,DIV BIOMOLEC ENGN,PARKVILLE,VIC 3052,AUSTRALIA.
   GLAXO GRP RES LTD,GREENFORD UB6 0HE,MIDDX,ENGLAND.
C3 Commonwealth Scientific & Industrial Research Organisation (CSIRO); GlaxoSmithKline; Glaxosmithkline United Kingdom
RP VONITZSTEIN, M (corresponding author), MONASH UNIV,VICTORIAN COLL PHARM,DEPT PHARMACEUT CHEM,381 ROYAL PARADE,PARKVILLE,VIC 3052,AUSTRALIA.
NR 41
TC 1604
Z9 1829
U1 5
U2 289
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 418
EP 423
DI 10.1038/363418a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800048
PM 8502295
DA 2026-03-10
ER

PT J
AU DERR, LK
   STRATHERN, JN
AF DERR, LK
   STRATHERN, JN
TI A ROLE FOR REVERSE TRANSCRIPTS IN GENE CONVERSION
SO NATURE
LA English
DT Article
ID mitotic recombination; yeast; selection
AB RECOMBINATION between a diffusible reverse transcript and its homologous chromosomal allele has been proposed as a mechanism for the precise removal of introns from DNA and gene conversion of dispersed repeated sequences1,2. We have reported that RNA-mediated recombination occurs in the yeast Saccharomyces cerevisiae3. This recombination requires expression of the retro-transposon Ty, and results in intron loss from a plasmid-borne marker gene and the formation of pseudogenes. Because the pseudogenes are embedded in Ty sequences, chromosomal insertion could have been mediated by Ty integrase or by homologous recombination with endogenous Ty sequences. The structure of the chromosomal recombinants and the fact that plasmid and chromosomal recombination can have different requirements demanded a direct demonstration of RNA-mediated gene conversion of a chromosomal allele. Here we report the first demonstration, to our knowledge, of recombination between a reverse transcript and its chromosomal homologue and describe an assay that specifically detects this novel recombination pathway.
RP DERR, LK (corresponding author), NCI,FREDERICK CANC RES & DEV CTR,EUKARYOT GENE EXPRESS LAB,FREDERICK,MD 21701, USA.
NR 13
TC 133
Z9 145
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 170
EP 173
DI 10.1038/361170a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600065
PM 8380627
DA 2026-03-10
ER

PT J
AU BURTON, J
   ROBERTS, D
   MONTALDI, M
   NOVICK, P
   DECAMILLI, P
AF BURTON, J
   ROBERTS, D
   MONTALDI, M
   NOVICK, P
   DECAMILLI, P
TI A MAMMALIAN GUANINE-NUCLEOTIDE-RELEASING PROTEIN ENHANCES FUNCTION OF YEAST SECRETORY PROTEIN SEC4
SO NATURE
LA English
DT Article
ID gtp-binding proteins; exchange factor; transformation; bud5; gene
AB SMALL GTP-binding proteins of the ras superfamily are important for exocytosis from eukaryotic cells1-5. GTP-binding proteins can exist in two different conformations depending on whether they are bound to GDP or GTP, and are thought to function as molecular switches that regulate a variety of cellular processes1,3. The GTP-GDP cycle is controlled by accessory proteins that promote the exchange of bound GDP or the hydrolysis of GTP. The protein Sec4, a member of the Sec4/Ypt1/Rab branch of the Ras superfamily, is involved in a late stage of the secretory pathway in yeast6. Here we report the isolation of a mammalian complementary DNA, mss4, encoding a GDP-releasing protein that enhances Sec4 function. The Mss4 protein also stimulates GDP release from Ypt1 and from the mammalian protein Rab3a, but not from Ras2. Mss4 shows sequence similarity to Dss4, a yeast protein with similar biochemical properties.7
C1 YALE UNIV,SCH MED,DEPT CELL BIOL,NEW HAVEN,CT 06510.
C3 Yale University
RP BURTON, J (corresponding author), YALE UNIV,SCH MED,HOWARD HUGHES MED INST,333 CEDAR ST,NEW HAVEN,CT 06510, USA.
NR 22
TC 115
Z9 123
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 464
EP 467
DI 10.1038/361464a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300065
PM 8429887
DA 2026-03-10
ER

PT J
AU SINGH, DJ
   KRAKAUER, H
   HAAS, C
   PICKETT, WE
AF SINGH, DJ
   KRAKAUER, H
   HAAS, C
   PICKETT, WE
TI THEORETICAL DETERMINATION THAT ELECTRONS ACT AS ANIONS IN THE ELECTRIDE CS+(15-CROWN-5)2.E-
SO NATURE
LA English
DT Article
ID alkalides
AB ELECTRIDES are crystalline salts formed from complexed alkali-metal cations. There has been some dispute as to whether the valence electron from the alkali ion becomes a trapped interstitial anion1,2 or resides at or near the alkali-metal nucleus3.  If the former description holds, electrides would represent stoichiometric counterparts of ionic insulators containing 'F-centre' electronic defects. Experiments1,2 have so far failed to resolve the question. Here we present ab initio self-consistent density-functional calculations4 of the electron distribution in the electride Cs+(15-crown-5)2.e-. We find that a spatially localized electron is located at the anion site, in accord with the F-centre model. Although the potential is in fact repulsive in this region, the electron is apparently forced to reside here by the need to lower its kinetic energy. We suggest that this picture may hold for other electrides as well.
C1 COLL WILLIAM & MARY,DEPT PHYS,WILLIAMSBURG,VA 23187.
C3 William & Mary
RP SINGH, DJ (corresponding author), USN,RES LAB,COMPLEX SYST THEORY BRANCH,WASHINGTON,DC 20375, USA.
NR 11
TC 104
Z9 110
U1 1
U2 34
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 39
EP 42
DI 10.1038/365039a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600047
DA 2026-03-10
ER

PT J
AU FRAIL, DA
   KULKARNI, SR
   VASISHT, G
AF FRAIL, DA
   KULKARNI, SR
   VASISHT, G
TI IDENTIFICATION OF PSR1758-23 AS A RUNAWAY PULSAR FROM THE SUPERNOVA REMNANT W28
SO NATURE
LA English
DT Article
ID absorption-measurements; inner galaxy; ionized-gas; scattering
AB THE discovery1 of the pulsar 1758 - 23 in the vicinity of the radio supernova remnant W28 has prompted speculation that the two might be physically associated. Although the brightening of the supernova remnant in the direction of the pulsar suggests such an association 2, the large column density of electrons in the interstellar medium towards PSR1758 - 23 (evident from the pronounced dispersion of the radio signal) and the anomalously large scattering observed in the pulses seem to indicate1,3 a distance much greater than that to W28. Here we present new observations which indicate that the large dispersion and scattering of the pulses is instead caused by a dense screen of ionized material located along the line of sight, and thus the distances to the pulsar and W28 can be reconciled. Similar scattering screens have been reported previously4,5 and appear to be associated with H II regions; the properties of these screens seem, however, to be inconsistent with current models6 of turbulent structure in the interstellar medium.
C1 CALTECH,DIV PHYS MATH & ASTRON 10524,PASADENA,CA 91125.
C3 California Institute of Technology
RP FRAIL, DA (corresponding author), NATL RADIO ASTRON OBSERV,SOCORRO,NM 87801, USA.
NR 24
TC 52
Z9 52
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 136
EP 138
DI 10.1038/365136a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200040
DA 2026-03-10
ER

PT J
AU STIXRUDE, L
   COHEN, RE
AF STIXRUDE, L
   COHEN, RE
TI STABILITY OF ORTHORHOMBIC MGSIO3 PEROVSKITE IN THE EARTHS LOWER MANTLE
SO NATURE
LA English
DT Article
ID (mg,fe)sio3 perovskite; phase-transitions; melting curve; high-pressure; state; equation; elasticity; simulation; dynamics; density
AB MAGNESIUM-rich silicate perovskite is thought to be the primary constituent of the Earth's lower mantle: experiments have shown1 MgSiO3 perovskite to be stable at lower-mantle pressures, and the elastic properties of perovskite-dominated assemblages agree well with seismological observations2-4. It has also been suggested5-8 that the observed orthorhombic structure will undergo displacive phase transitions to higher-symmetry structures at lower-mantle conditions. The presence of such transitions would have important consequences for mantle convection9, and could provide an explanation for some of the weak seismic discontinuities observed10-12 in the lower mantle. However, the determination of the phase behaviour Of MgSiO3 perovskite at lower-mantle conditions has so far eluded both experimental and theoretical efforts. Here we report the results of electronic-structure calculations of the energetics of displacive phase transitions in MgSiO3 perovskite, and demonstrate that the lower-symmetry orthorhombic phase should be highly favoured throughout the lower mantle. Our results are consistent with recent experiments13 on MgSiO3 perovskite encompassing the temperatures and pressures of the uppermost regions of the lower mantle.
C1 CARNEGIE INST WASHINGTON,GEOPHYS LAB,WASHINGTON,DC 20015.
   CARNEGIE INST WASHINGTON,CTR HIGH PRESSURE RES,WASHINGTON,DC 20015.
C3 Carnegie Institution for Science; Carnegie Institution for Science
RP STIXRUDE, L (corresponding author), GEORGIA INST TECHNOL,SCH EARTH & ATMOSPHER SCI,ATLANTA,GA 30332, USA.
NR 43
TC 100
Z9 110
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 613
EP 616
DI 10.1038/364613a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100048
DA 2026-03-10
ER

PT J
AU BLASI, J
   CHAPMAN, ER
   LINK, E
   BINZ, T
   YAMASAKI, S
   DECAMILLI, P
   SUDHOF, TC
   NIEMANN, H
   JAHN, R
AF BLASI, J
   CHAPMAN, ER
   LINK, E
   BINZ, T
   YAMASAKI, S
   DECAMILLI, P
   SUDHOF, TC
   NIEMANN, H
   JAHN, R
TI BOTULINUM NEUROTOXIN-A SELECTIVELY CLEAVES THE SYNAPTIC PROTEIN SNAP-25
SO NATURE
LA English
DT Article
ID synaptosomal-associated protein; motor-nerve terminals; membrane-protein; clostridial neurotoxins; secretory pathway; vesicles; identification; synaptobrevin; exocytosis; receptor
AB NEUROTRANSMITTER release is potently blocked by a group of structurally related toxin proteins produced by Clostridium botulinum1. Botulinum neurotoxin type B (BoNT/B) and tetanus toxin (TeTx) are zinc-dependent proteases that specifically cleave synaptobrevin (VAMP), a membrane protein of synaptic vesicles2,3. Here we report that inhibition of transmitter release from synaptosomes caused by botulinum neurotoxin A (BoNT/A) is associated with the selective proteolysis of the synaptic protein SNAP-25. Furthermore, isolated or recombinant L chain of BoNT/A cleaves SNAP-25 in vitro. Cleavage occurred near the carboxyterminus and was sensitive to divalent cation chelators. In addition, a glutamate residue in the BoNT/A L chain, presumably required to stabilize a water molecule in the zinc-containing catalytic centre, was required for proteolytic activity. These findings demonstrate that BoNT/A acts as a zinc-dependent protease that selectively cleaves SNAP-25. Thus, a second component of the putative fusion complex mediating synaptic vesicle exocytosis is targeted by a clostridial neurotoxin.
C1 FED RES CTR VIRUS DIS ANIM,INST MICROBIOL,W-7400 TUBINGEN,GERMANY.
   UNIV TEXAS,SW MED CTR,DEPT MOLEC GENET,DALLAS,TX 75235.
   UNIV TEXAS,SW MED CTR,HOWARD HUGHES MED CTR,DALLAS,TX 75235.
   YALE UNIV,SCH MED,HOWARD HUGHES MED INST,NEW HAVEN,CT 06510.
   YALE UNIV,SCH MED,DEPT PHARMACOL,NEW HAVEN,CT 06510.
   YALE UNIV,SCH MED,DEPT CELL BIOL,NEW HAVEN,CT 06510.
   UNIV BARCELONA,SCH MED,DEPT CELL BIOL & PATHOL,BARCELONA 7,SPAIN.
C3 University of Texas System; University of Texas Dallas; University of Texas Southwestern Medical Center; University of Texas System; University of Texas Dallas; University of Texas Southwestern Medical Center; Howard Hughes Medical Institute; Yale University; Yale University; Yale University; University of Barcelona
NR 30
TC 1012
Z9 1167
U1 2
U2 99
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 160
EP 163
DI 10.1038/365160a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200048
PM 8103915
DA 2026-03-10
ER

PT J
AU MCLACHLAN, EM
   JANIG, W
   DEVOR, M
   MICHAELIS, M
AF MCLACHLAN, EM
   JANIG, W
   DEVOR, M
   MICHAELIS, M
TI PERIPHERAL-NERVE INJURY TRIGGERS NORADRENERGIC SPROUTING WITHIN DORSAL-ROOT GANGLIA
SO NATURE
LA English
DT Article
ID sensory neurons; rat; noradrenaline; modes; cat
AB IN humans, trauma to a peripheral nerve may be followed by chronic pain syndromes which are only relieved by blockade of the effects of sympathetic impulse traffic1-4. It is presumed that, after the lesion, noradrenaline released by activity of sympathetic postganglionic axons excites primary afferent neurons by activating alpha-adrenoceptors2,5, generating signals that enter the 'pain pathways' of the central nervous system. The site of coupling is unclear. In some patients local anaesthesia of the relevant peripheral nerve6  does not alleviate pain, implying that ectopic impulses arise either within the central nervous system, or in proximal parts of the primary afferent neurons. In experimentally lesioned rats, activity can originate within the dorsal root ganglia7,8. Here we report that, after sciatic nerve ligation, noradrenergic perivascular axons in rats sprout into dorsal root ganglia and form basket-like structures around large-diameter axotomized sensory neurons; sympathetic stimulation can activate such neurons repetitively. These unusual connections provide a possible origin for abnormal discharge following peripheral nerve damage. Further, in contrast to the sprouting of intact nerve terminals into nearby denervated effector tissues in skin9,10, muscle11, sympathetic ganglia12 and sweat glands13, the axons sprout into a target which has not been-partially denervated.
C1 CHRISTIAN ALBRECHTS UNIV KIEL,INST PHYSIOL,W-2300 KIEL 1,GERMANY.
   HEBREW UNIV JERUSALEM,INST ORAL HLTH RES,DEPT CELL & ANIM BIOL,IL-91904 JERUSALEM,ISRAEL.
C3 University of Kiel; Hebrew University of Jerusalem
RP MCLACHLAN, EM (corresponding author), UNIV QUEENSLAND,DEPT PHYSIOL & PHARMACOL,BRISBANE,QLD 4072,AUSTRALIA.
NR 30
TC 604
Z9 674
U1 2
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 543
EP 546
DI 10.1038/363543a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900050
PM 8505981
DA 2026-03-10
ER

PT J
AU KELLER, M
   VELDKAMP, E
   WEITZ, AM
   REINERS, WA
AF KELLER, M
   VELDKAMP, E
   WEITZ, AM
   REINERS, WA
TI EFFECT OF PASTURE AGE ON SOIL TRACE-GAS EMISSIONS FROM A DEFORESTED AREA OF COSTA-RICA
SO NATURE
LA English
DT Article
ID tropical forest; nitrous-oxide
AB MEASUREMENTS of the flux of nitrous oxide-an important greenhouse gas-from recently formed pasture in the Amazon basin have shown a threefold increase relative to the flux from the original forest soil1. Based on these measurements, Luizao et al.1 estimated that present rates of conversion from forest to pasture supply up to 1 Tg of N2O-N to the atmosphere each year, corresponding to less-than-or-equal-to 25% of the current imbalance between sources and sinks of this gas. But this estimate assumes that such conversion produces elevated fluxes that remain constant in time. To assess the validity of this assumption, we present measurements of trace-gas fluxes from Costa Rican pastures of varying ages. Nitrogen oxide fluxes peak during the first ten years after conversion, but decline thereafter to values that are even lower than the original forest fluxes. We conclude that previous studies have overestimated the contribution of pastures to the global budget of nitrous oxide, and that accurate predictions of soil-atmosphere trace-gas fluxes will require a detailed knowledge not only of current land use, but also of land-use history.
C1 AGR UNIV WAGENINGEN,DEPT SOIL SCI & GEOL,6700 AA WAGENINGEN,NETHERLANDS.
   UNIV WYOMING,DEPT BOT,LARAMIE,WY 82071.
C3 Wageningen University & Research; University of Wyoming
RP KELLER, M (corresponding author), US FOREST SERV,INT INST TROP FORESTRY,CALL BOX 25000,RIO PIEDRAS,PR 00928, USA.
NR 19
TC 194
Z9 205
U1 0
U2 27
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 244
EP 246
DI 10.1038/365244a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100051
DA 2026-03-10
ER

PT J
AU JONES, IL
   HUNTER, FM
AF JONES, IL
   HUNTER, FM
TI MUTUAL SEXUAL SELECTION IN A MONOGAMOUS SEABIRD
SO NATURE
LA English
DT Article
ID guppy poecilia-reticulata; female choice; tail length; dimorphism; evolution; auklets; males; least
AB DARWIN1 believed that elaborate ornamental traits expressed in both sexes might be favoured by mutual sexual selection driven by both female and male mate choice. Experimental studies on birds2-5 and fish6-9 have shown that male ornaments can be favoured by female mating preferences. But the concept of mutual mate choice has remained untested experimentally, although it has been supported by recent modelling10. Here we report the results of a study of mate preferences of the crested auklet Aethia cristatella, a monogamous seabird in which both sexes are ornamented. In two experiments we recorded the sexual response of male and female auklets to realistic opposite-sex models with crest ornaments experimentally shortened and lengthened within the range of natural variation. Males responded to accentuated female models with more frequent sexual displays, as did females to accentuated male models, confirming the idea that ornaments expressed in both sexes could be favoured by mutual mating preferences.
C1 UNIV CAMBRIDGE,DEPT ZOOL,CAMBRIDGE CB2 3EJ,ENGLAND.
C3 University of Cambridge
NR 23
TC 285
Z9 319
U1 1
U2 96
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 238
EP 239
DI 10.1038/362238a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600053
DA 2026-03-10
ER

PT J
AU MCGLADEMCCULLOH, E
   YAMAMOTO, H
   TAN, SE
   BRICKEY, DA
   SODERLING, TR
AF MCGLADEMCCULLOH, E
   YAMAMOTO, H
   TAN, SE
   BRICKEY, DA
   SODERLING, TR
TI PHOSPHORYLATION AND REGULATION OF GLUTAMATE RECEPTORS BY CALCIUM CALMODULIN-DEPENDENT PROTEIN KINASE-II
SO NATURE
LA English
DT Article
ID postsynaptic density protein; molecular-cloning; subunit; expression; brain; binding; kainate; system; ampa
AB THE major postsynaptic density (PSD) protein1,2 at glutaminergic synapses is calcium/calmodulin-dependent protein kinase II (CaM-K II), but its function in the PSD is not known. We have examined glutamate receptors (GluRs) as substrates for CaM-K II because (1) they are colocalized in the PSD3, (2) cloned GluRs4-7 contain consensus phosphorylation sites for protein kinases including CaM-K II, and (3) several GluRs are regulated by other protein kinases8-12. Regulation of GluRs, which are involved in excitatory synaptic transmission and in mechanisms of learning and memory13, by CaM-K II is of interest because of the postulated role of CaM-K II in synaptic plasticity14,15 and its known involvement in induction of long-term potentiation16. Furthermore, mice lacking the major neural isoform of CaM-K II exhibit deficits in models of learning and memory that require hippocampal input17,18. We report here that CaM-K II phosphorylates GluR in several in vitro systems, including the PSD, and that activated CaM-K II enhances kainate-induced ion current three- to fourfold in cultured hippocampal neurons. These results are consistent with a role for PSD CaM-K II in strengthening postsynaptic GluR responses in synaptic plasticity.
C1 OREGON HLTH SCI UNIV,VOLLUM INST,3181 SW SAM JACKSON PK RD,PORTLAND,OR 97201.
C3 Oregon Health & Science University
NR 30
TC 353
Z9 387
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 640
EP 642
DI 10.1038/362640a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800051
PM 8385275
DA 2026-03-10
ER

PT J
AU STREHLOW, D
   GILBERT, W
AF STREHLOW, D
   GILBERT, W
TI A FATE MAP FOR THE 1ST CLEAVAGES OF THE ZEBRAFISH
SO NATURE
LA English
DT Article
ID cell lineage; blastomeres; gastrula; embryo
AB A FATE map depicts how lineages from a defined blastomere will be restricted to particular tissues. In the amphibian Xenopus laevis, the early blastomeres of the embryo have traceable lineages1-4. However, it has been thought that mixing of the blastomeres of Brachydanio rerio prevents them from giving rise to a fate map5-10. For this reason the zebrafish has been used as an example of a class of embryos, including mammals, which apparently exhibit little fate until later in embryogenesis. The amphibia were the exception. We report here the use of fluorescent dyes on very-high-molecular-mass carriers to trace a fate map from the first three cleavages of the zebrafish embryo to the three principal adult body axes: the first cleavage defines dorsal-ventral; the second cleavage, left-right; and the third, anterior-posterior.
C1 HARVARD UNIV,DEPT CELLULAR & DEV BIOL,BIOL LABS,CAMBRIDGE,MA 02138.
C3 Harvard University
RP STREHLOW, D (corresponding author), BOSTON UNIV HOSP,DEPT BIOMOLEC MED,88 E NEWTON ST,BOSTON,MA 02118, USA.
NR 12
TC 53
Z9 56
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 451
EP 453
DI 10.1038/361451a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300061
DA 2026-03-10
ER

PT J
AU OGAWA, O
   ECCLES, MR
   SZETO, J
   MCNOE, LA
   YUN, K
   MAW, MA
   SMITH, PJ
   REEVE, AE
AF OGAWA, O
   ECCLES, MR
   SZETO, J
   MCNOE, LA
   YUN, K
   MAW, MA
   SMITH, PJ
   REEVE, AE
TI RELAXATION OF INSULIN-LIKE GROWTH FACTOR-II GENE IMPRINTING IMPLICATED IN WILMS-TUMOR
SO NATURE
LA English
DT Article
ID wiedemann-beckwith syndrome; carcinogenesis; disomy
AB GENOMIC imprinting has been implicated in the onset of several embryonal tumours but the mechanism is not well understood1-3. Maternal chromosome 11p15 loss of heterozygosity4 and paternal chromosome 11 isodisomy 5,6 suggest that imprinted genes are involved in the onset of Wilms' tumour and the Beckwith-Wiedemann syndrome. The insulin-like growth factor II (IGF2) gene located at 11p15.5 has been put forward as a candidate gene as it is maternally imprinted (paternally expressed) in the mouse7, and is expressed at high levels in Wilms' tumours8,9. We report here that the IGF2 gene is expressed from the paternal allele in human fetal tissue, but that in Wilms' tumour expression can occur biallelically. These results provide, to our knowledge, the first evidence that relaxation of imprinting may play a role in the onset of disease and suggest a new genetic mechanism involved in the development of cancer.
C1 UNIV OTAGO, DEPT BIOCHEM, CANC GENET LAB, DUNEDIN, NEW ZEALAND.
   UNIV OTAGO, DEPT PATHOL, DUNEDIN, NEW ZEALAND.
   UNIV QUEENSLAND, DEPT PATHOL, HERSTON, QLD 4006, AUSTRALIA.
C3 University of Otago; University of Otago; University of Queensland
NR 21
TC 691
Z9 741
U1 0
U2 12
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 749
EP 751
DI 10.1038/362749a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000056
PM 8097018
DA 2026-03-10
ER

PT J
AU ZAKANY, J
   DUBOULE, D
AF ZAKANY, J
   DUBOULE, D
TI CORRELATION OF EXPRESSION OF WNT-1 IN DEVELOPING LIMBS WITH ABNORMALITIES IN GROWTH AND SKELETAL PATTERNING
SO NATURE
LA English
DT Article
ID int-1 protooncogene; transgenic mice; gene; organization
AB THE Wnt genes are members of a family of vertebrate genes related to the Drosophila gene wingless (wg)1,2. They encode secreted molecules3,4 that are thought to be important in patterning and growth control during ontogenesis5-7. Several such genes are transcribed in localized domains during limb budding and morphogenesis2,8. We report here a congenital limb malformation in a mouse transgenic line that ectopically expresses Wnt-1 in the developing limbs. The hemizygote phenotype, which is inherited as an autosomal dominant trait, presents extensive distal truncations of skeletal elements, skeletal fusions and interdigital webbing. The data shown here demonstrate that abnormal Wnt-1 expression is correlated with retarded mesenchymal condensations replaced by highly proliferative cells in the limb bud. This seems to lead to an inability of the affected cells to participate in normal skeletal development leading to the adult defects.
RP ZAKANY, J (corresponding author), EUROPEAN MOLEC BIOL LAB,MEYERHOFSTR 1,POSTFACH 10-2209,W-6900 HEIDELBERG,GERMANY.
NR 23
TC 55
Z9 62
U1 2
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 546
EP 549
DI 10.1038/362546a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300056
PM 8464495
DA 2026-03-10
ER

PT J
AU LERNBECHER, T
   MULLER, U
   WIRTH, T
AF LERNBECHER, T
   MULLER, U
   WIRTH, T
TI DISTINCT NF-KAPPA-B REL TRANSCRIPTION FACTORS ARE RESPONSIBLE FOR TISSUE-SPECIFIC AND INDUCIBLE GENE ACTIVATION
SO NATURE
LA English
DT Article
ID dna-binding activity; kappa-b; proto-oncogene; p65 subunit; c-rel; enhancer; interact; cloning; sequences; promoter
AB THE NF-kappaB/Rel family is a growing class of transcriptional regulators1-11 whose members share the conserved Rel-homology domain, involved in specific DNA binding and dimerization. They interact with the regulatory elements of many different genes and are involved in the regulation of lymphoid-specific and inducible transcription12. We tested whether these factors could alone activate a gene in transgenic mice. We report here that a minimal promoter containing three copies of a binding site for these proteins allows tissue-specific and inducible transgene activation. In lymphoid tissues constitutive transgene expression correlates with the presence of a constitutively active p50/RelB heterodimer. Other organs that only contain the p50 homodimer do not express the transgene. In contrast to this constitutive activity mediated by p50/RelB, the p50/p65 heterodimer (which is NF-kappaB) could confer inducible transgene activation in embryo fibroblasts. Thus two different members of the NF-kappaB/Rel family of transcriptional activators are involved in tissue-specific and inducible gene activation in transgenic mice.
C1 ZENTRUM MOLEK BIOL HEIDELBERG,NEUENHEIMER FELD 282,W-6900 HEIDELBERG,GERMANY.
   BASEL INST IMMUNOL,CH-4005 BASEL,SWITZERLAND.
C3 Ruprecht Karls University Heidelberg
NR 29
TC 197
Z9 204
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 767
EP 770
DI 10.1038/365767a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200068
PM 7692309
DA 2026-03-10
ER

PT J
AU CHYBA, CF
   THOMAS, PJ
   ZAHNLE, KJ
AF CHYBA, CF
   THOMAS, PJ
   ZAHNLE, KJ
TI THE 1908 TUNGUSKA EXPLOSION - ATMOSPHERIC DISRUPTION OF A STONY ASTEROID
SO NATURE
LA English
DT Article
ID meteor fall; comet; event; breakup; earth
AB The explosion over Tunguska, Central Siberia, in 1908 released 10 to 20 megatons (high explosive equivalent) of energy at an altitude of about 10 km. This event represents a typical fate for stony asteroids tens of metres in radius entering the Earth's atmosphere at common hypersonic velocities. Comets and carbonaceous asteroids of the appropriate energy disrupt too high, whereas typical iron objects reach and crater the terrestrial surface.
C1 NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035.
   UNIV WISCONSIN,DEPT PHYS & ASTRON,EAU CLAIRE,WI 54702.
C3 National Aeronautics & Space Administration (NASA); NASA Ames Research Center; University of Wisconsin System
NR 45
TC 391
Z9 439
U1 0
U2 61
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 40
EP 44
DI 10.1038/361040a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800039
DA 2026-03-10
ER

PT J
AU MCMAHON, HT
   USHKARYOV, YA
   EDELMANN, L
   LINK, E
   BINZ, T
   NIEMANN, H
   JAHN, R
   SUDHOF, TC
AF MCMAHON, HT
   USHKARYOV, YA
   EDELMANN, L
   LINK, E
   BINZ, T
   NIEMANN, H
   JAHN, R
   SUDHOF, TC
TI CELLUBREVIN IS A UBIQUITOUS TETANUS-TOXIN SUBSTRATE HOMOLOGOUS TO A PUTATIVE SYNAPTIC VESICLE FUSION PROTEIN
SO NATURE
LA English
DT Article
ID membrane-protein; synaptophysin; microvesicles; pc12-cells; genes
AB TETANUS toxin inhibits neurotransmitter release by selectively blocking fusion of synaptic vesicles1,2. Recently tetanus toxin was shown to proteolytically degrade synaptobrevin II (also named VAMP-2), a synaptic vesicle-specific protein3,4, in vitro and in nerve terminals5,6. As targets of tetanus toxin, synaptobrevins probably function in the exocytotic fusion of synaptic vesicles. Here we describe a new synaptobrevin homologue, cellubrevin, that is present in all cells and tissues tested and demonstrate that it is a membrane trafficking protein of a constitutively recycling pathway. Like synaptobrevin II, cellubrevin is proteolysed by tetanus toxin light chain in vitro and after transfection. Our results suggest that constitutive and regulated vesicular pathways use homologous proteins for membrane trafficking, probably for membrane fusion at the plasma membrane, indicating a greater mechanistic and evolutionary similarity between these pathways than previously thought.
C1 UNIV TEXAS,SW MED CTR,HOWARD HUGHES MED INST,DALLAS,TX 75235.
   UNIV TEXAS,SW MED CTR,DEPT MED GENET,DALLAS,TX 75235.
   YALE UNIV,HOWARD HUGHES MED INST,NEW HAVEN,CT 06510.
   YALE UNIV,DEPT CELL BIOL,NEW HAVEN,CT 06510.
   YALE UNIV,DEPT PHARMACOL,NEW HAVEN,CT 06510.
   FED RES CTR VIRUS DIS ANIM,W-7400 TUBINGEN,GERMANY.
C3 Howard Hughes Medical Institute; University of Texas System; University of Texas Southwestern Medical Center; University of Texas Dallas; University of Texas System; University of Texas Dallas; University of Texas Southwestern Medical Center; Yale University; Howard Hughes Medical Institute; Yale University; Yale University
NR 29
TC 443
Z9 476
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 346
EP 349
DI 10.1038/364346a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000060
PM 8332193
DA 2026-03-10
ER

PT J
AU GROSOF, DH
   SHAPLEY, RM
   HAWKEN, MJ
AF GROSOF, DH
   SHAPLEY, RM
   HAWKEN, MJ
TI MACAQUE-V1 NEURONS CAN SIGNAL ILLUSORY CONTOURS
SO NATURE
LA English
DT Article
ID monkey visual-cortex; subjective contours; perception; sensitivity; organization; mechanisms; elements; contrast; motion; cues
AB WE describe here a new view of primary visual cortex (V1) based on measurements of neural responses in V1 to patterns called 'illusory contours' (Fig. 1a, b). Detection of an object's boundary contours is a fundamental visual task. Boundary contours are defined by discontinuities not only in luminance and colour, but also in texture1-3, disparity4 and motion5-7. Two theoretical approaches can account for illusory contour perception. The cognitive approach emphasizes top-down processes8,9. An alternative emphasizes bottom-up processing. This latter view is supported by (1) stimulus constraints for illusory contour perception10-14 and (2) the discovery by von der Heydt and Peterhans15-17 of neurons in extrastriate visual area V2 (but not in V1) of macaque monkeys that respond to illusory contours. Using stimuli different from those used previously15,16, we found illusory contour responses in about half the neurons studied in V1 of macaque monkeys. Therefore, there are neurons as early as V1 with the computational power to detect illusory contours and to help distinguish figure from ground.
C1 NYU,CTR NEURAL SCI,4 WASHINGTON PL,NEW YORK,NY 10003.
C3 New York University
NR 27
TC 318
Z9 348
U1 0
U2 32
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 550
EP 552
DI 10.1038/365550a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100055
PM 8413610
DA 2026-03-10
ER

PT J
AU ROY, AL
   CARRUTHERS, C
   GUTJAHR, T
   ROEDER, RG
AF ROY, AL
   CARRUTHERS, C
   GUTJAHR, T
   ROEDER, RG
TI DIRECT ROLE FOR MYC IN TRANSCRIPTION INITIATION MEDIATED BY INTERACTIONS WITH TFII-I
SO NATURE
LA English
DT Article
ID c-myc; dna-binding; proteins; max; dimerization; activation; oncogene; sequence; myod; usf
AB THE nuclear proto-oncoprotein Myc has been implicated in the control of cell proliferation and differentiation1-3. Myc participates in transcription4,5 and belongs to the basic-helix-loop-helix (bHLH) family of regulatory proteins2,3. Here we show that Myc interacts with TFII-I, a transcription initiation factor that activates core promoters through an initiator element (Inr)6. As previously observed for the bHLH activator USF6, Myc was found to interact cooperatively with TFII-I at both Inr and upstream E-box promoter elements. However, in this case Myc interactions with TFII-I at the Inr lead to an inhibition of transcription initiation. This inhibition is selective for a TFII-I-dependent (as opposed to TFIIA-dependent) initiation pathway and correlates with the prevention of complex formation between the TATA-binding protein TBP (TFIIDtau), TFII-I and the promoter. TBP probably interacts with Myc, but only slowly. These observations indicate that Myc has the potential to interact physically and functionally with components of the general transcription machinery.
RP ROY, AL (corresponding author), ROCKEFELLER UNIV,BIOCHEM & MOLEC BIOL LAB,1230 YORK AVE,NEW YORK,NY 10021, USA.
NR 27
TC 251
Z9 267
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 359
EP 361
DI 10.1038/365359a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600058
PM 8377829
DA 2026-03-10
ER

PT J
AU NAKAMURA, M
   KITAMORI, T
   SAWADA, T
AF NAKAMURA, M
   KITAMORI, T
   SAWADA, T
TI HIGHLY ANISOTROPIC LIGHT-EMISSION FROM LASER BREAKDOWN OF MICROPARTICLES IN WATER
SO NATURE
LA English
DT Article
ID stimulated raman-scattering; spectrochemical analysis; droplets; plasmas; liquids; time
AB LASER breakdown, in which a substance is transformed explosively to a plasma by a focused pulsed laser beam, has been much studied1-8. Light emission from the plasma formed by breakdown of liquid media or suspended microparticles is generally observed lateral to the laser beam, and can be used for spectrochemical analysis4,8,9. Here we report the observation of highly anisotropic emission of hydrogen Balmer-alpha (Halpha) radiation from the laser breakdown of polystyrene particles in water. The emission was strong and spectrally narrow in the forward and backward directions (with respect to the beam), and weak and broad in others. The incorporation of a single-mirror cavity in the optical arrangement and the observed nonlinear dependence of intensity on the focal-length of the focusing lens suggest that the plasma may induce gain in the emitted radiation. The exact mechanism of the anisotropic emission is not yet known.
C1 UNIV TOKYO,FAC ENGN,DEPT IND CHEM,7-3-1 HONGO,BUNKYO KU,TOKYO 113,JAPAN.
C3 University of Tokyo
NR 13
TC 3
Z9 3
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 138
EP 141
DI 10.1038/366138a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600050
DA 2026-03-10
ER

PT J
AU IONOV, Y
   PEINADO, MA
   MALKHOSYAN, S
   SHIBATA, D
   PERUCHO, M
AF IONOV, Y
   PEINADO, MA
   MALKHOSYAN, S
   SHIBATA, D
   PERUCHO, M
TI UBIQUITOUS SOMATIC MUTATIONS IN SIMPLE REPEATED SEQUENCES REVEAL A NEW MECHANISM FOR COLONIC CARCINOGENESIS
SO NATURE
LA English
DT Article
ID arbitrary primers; chain-reaction; dna; polymorphisms; mutagenesis; invitro; cancer
AB SPONTANEOUS errors in DNA replication have been suggested to play a significant role in neoplastic transformation and to explain the chromosomal alterations seen in cancer cells1. A defective replication factor could increase the mutation rate in clonal variants arising during tumour progression, but despite intensive efforts, increases in tumour cell mutation rates have not been unambiguously shown2. Here we use an unbiased genomic fingerprinting technique3 to show that 12 per cent of colorectal carcinomas carry somatic deletions in poly(dA . dT) sequences and other simple repeats. We estimate that cells from these tumours can carry more than 100,000 such mutations. Only tumours with affected poly(dA . dT) sequences carry mutations in the other simple repeats examined, and such mutations can be found in all neoplastic regions of multiple tumours from the same patient, including adenomas. Tumours with these mutations show distinctive genotypic and phenotypic features. We conclude that these mutations reflect a previously undescribed form of carcinogenesis in the colon (predisposition to which may be inherited) mediated by a mutation in a DNA replication factor resulting in reduced fidelity for replication or repair (a 'mutator mutation').
C1 CALIF INST BIOL RES,11099 N TORREY PINES RD,LA JOLLA,CA 92037.
   UNIV SO CALIF,SCH MED,DEPT PATHOL,LOS ANGELES,CA 90033.
C3 University of Southern California
NR 23
TC 2422
Z9 2616
U1 0
U2 94
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 558
EP 561
DI 10.1038/363558a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900055
PM 8505985
DA 2026-03-10
ER

PT J
AU GAO, GQ
AF GAO, GQ
TI THE TEMPERATURES AND OXYGEN-ISOTOPE COMPOSITION OF EARLY DEVONIAN OCEANS
SO NATURE
LA English
DT Article
ID abiotic marine calcite; brachiopods; geochemistry; sr-87/sr-86; indicators; delta-c-13; oklahoma; seawater; records; ratios
AB THE oxygen isotope composition of pre-Carboniferous (>360 Myr old) marine carbonates, cherts and phosphates has been reported1-8 to be lower than that of later (post-Devonian) samples. According to one explanation1,3, this is a reflection of warmer (generally greater-than-or-equal-to 40-degrees-C) pre-Carboniferous oceans relative to modern oceans. Alternatively, it has been proposed5,7 that the pre-Carboniferous oceans were depleted in O-18 (by 2 parts per thousand SMOW) relative to modern oceans. Here I report high deltaO-18 values (-1.9 to -2.9 parts per thousand PDB) in normal, shallow-marine limestones (and three brachiopod shells) from the Lower Devonian Haragan and Bois d'Arc formations in south-central Oklahoma. I interpret these values as near-primary, and therefore constraining the temperature and oxygen isotope composition of early Devonian sea water to 25+/-7-degrees-C and 0+/-1 parts per thousand SMOW respectively. In conjunction with similarly high deltaO-18 values obtained from older (Ordovician and Silurian) samples8, these results imply that the temperature and oxygen isotope composition of pre-Carboniferous oceans may, at least during some time intervals, have been similar to those of modern oceans.
RP GAO, GQ (corresponding author), UNIV TEXAS,DEPT GEOL SCI,AUSTIN,TX 78712, USA.
NR 29
TC 17
Z9 18
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 712
EP 714
DI 10.1038/361712a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900051
DA 2026-03-10
ER

PT J
AU TACKLEY, PJ
   STEVENSON, DJ
   GLATZMAIER, GA
   SCHUBERT, G
AF TACKLEY, PJ
   STEVENSON, DJ
   GLATZMAIER, GA
   SCHUBERT, G
TI EFFECTS OF AN ENDOTHERMIC PHASE-TRANSITION AT 670 KM DEPTH IN A SPHERICAL MODEL OF CONVECTION IN THE EARTHS MANTLE
SO NATURE
LA English
DT Article
ID long-wavelength heterogeneity; northwest pacific; island arcs; mgsio3 perovskite; slab; lithosphere; predominance; generation
AB Numerical modelling of mantle convection in a spherical shell with an endothermic phase change at 670 km depth reveals an inherently three-dimensional flow pattern, containing cylindrical plumes and linear sheets which behave differently in their ability to penetrate the phase change. The dynamics are dominated by accumulation of downwelling cold material above 670 km depth, resulting in frequent avalanches of upper-mantle material into the lower mantle. This process generates long-wavelength lateral heterogeneity, helping to resolve the contradiction between seismic tomographic observations and expectations from mantle convection simulations.
C1 CALTECH,DIV GEOL & PLANETARY SCI,PASADENA,CA 91125.
   LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,LOS ALAMOS,NM 87545.
   LOS ALAMOS NATL LAB,INST GEOPHYS & PLANETARY PHYS,LOS ALAMOS,NM 87545.
   UNIV CALIF LOS ANGELES,DEPT EARTH & SPACE SCI,LOS ANGELES,CA 90024.
   UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024.
C3 California Institute of Technology; United States Department of Energy (DOE); Los Alamos National Laboratory; United States Department of Energy (DOE); Los Alamos National Laboratory; University of California System; University of California Los Angeles; University of California System; University of California Los Angeles
RP TACKLEY, PJ (corresponding author), CALTECH,SEISMOL LAB,PASADENA,CA 91125, USA.
NR 49
TC 504
Z9 532
U1 1
U2 61
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 699
EP 704
DI 10.1038/361699a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900046
DA 2026-03-10
ER

PT J
AU BAKER, A
   SMART, PL
   EDWARDS, RL
   RICHARDS, DA
AF BAKER, A
   SMART, PL
   EDWARDS, RL
   RICHARDS, DA
TI ANNUAL GROWTH BANDING IN A CAVE STALAGMITE
SO NATURE
LA English
DT Article
AB THE presence of microscopic luminescence banding in cave calcite deposits (speleothems) has recently been reported1-3. The luminescence seems to be caused by excitation of humic and fulvic acids derived from the overlying soil and subsequently incorporated into the calcite3,4. We have tested whether such luminescence corresponds to annual growth layers, using high-precision thermal-ionization mass-spectrometric U-238-U-234-U-Th-230 ages from banded sections of a Holocene stalagmite. We report here that the timespans yielded by counting bands, on the assumption that they are annual, agree within error limits with those obtained by our uranium-thorium dating. This demonstration that the banding is annual should make banded speleothems valuable resources for providing high-resolution records of past climate (in which precipitation can be estimated from growth rates5,6 and temperatures from stable-isotope measurements7) and solar-terrestrial correlations (as the luminescence intensity can be related to the solar sunspot cycle1-3).
C1 UNIV MINNESOTA, DEPT GEOL & GEOPHYS, MINNESOTA ISOTOPE LAB, MINNEAPOLIS, MN 55455 USA.
C3 University of Minnesota System; University of Minnesota Twin Cities
RP BAKER, A (corresponding author), UNIV BRISTOL, DEPT GEOG, BRISTOL BS8 1SS, ENGLAND.
NR 19
TC 221
Z9 289
U1 0
U2 38
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 518
EP 520
DI 10.1038/364518a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700050
DA 2026-03-10
ER

PT J
AU MCKENNALAWLOR, SMP
   DALY, PW
   KIRSCH, E
   OSULLIVAN, D
   THOMPSON, A
   WENZEL, KP
   AFONIN, V
AF MCKENNALAWLOR, SMP
   DALY, PW
   KIRSCH, E
   OSULLIVAN, D
   THOMPSON, A
   WENZEL, KP
   AFONIN, V
TI ENERGETIC IONS AT COMET GRIGG-SKJELLERUP MEASURED FROM THE GIOTTO SPACECRAFT
SO NATURE
LA English
DT Article
AB ON 10 July 1992, the Giotto spacecraft flew within about 200 km of the nucleus of comet Grigg-Skjellerup; this is only the third comet at which in situ measurements have been made, and the encounter constituted the closest approach so far of a spacecraft to a cometary nucleus. Here we report the detection by the EPONA instrument on Giotto of charged, energetic particles deep within the inner coma of Grigg-Skjellerup. In contrast to previous spacecraft encounters with comets Giacobini-Zinner (in 1985) and Halley (in 1986), well defined, periodic intensity variations recorded in the particle fluxes suggest that the ions close to the nucleus were strongly coupled to the ambient magnetic field. The present data indicate that Giotto new on the nightside of the nucleus.
C1 MAX PLANCK INST AERON,W-3411 KATLENBURG DUHM,GERMANY.
   DUBLIN INST ADV STUDIES,DUBLIN 4,IRELAND.
   ESA,ESTEC,DEPT SPACE SCI,2200 AG NOORDWIJK,NETHERLANDS.
   MOSCOW SPACE RES INST,MOSCOW 117810,RUSSIA.
C3 Max Planck Society; Dublin Institute for Advanced Studies; European Space Agency; European Space Research & Technology Centre; Russian Academy of Sciences; Space Research Institute of the Russian Academy of Sciences
RP MCKENNALAWLOR, SMP (corresponding author), ST PATRICKS COLL,MAYNOOTH,KILDARE,IRELAND.
NR 7
TC 16
Z9 16
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 326
EP 329
DI 10.1038/363326a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700044
DA 2026-03-10
ER

PT J
AU WU, XC
   BRINKMAN, DB
   RUSSELL, AP
   DONG, ZM
   CURRIE, PJ
   HOU, LH
   CUI, GH
AF WU, XC
   BRINKMAN, DB
   RUSSELL, AP
   DONG, ZM
   CURRIE, PJ
   HOU, LH
   CUI, GH
TI OLDEST KNOWN AMPHISBAENIAN FROM THE UPPER CRETACEOUS OF CHINESE INNER-MONGOLIA
SO NATURE
LA English
DT Article
ID lizard
AB THE amphisbaenians, lizards and snakes constitute a monophyletic group, the Squamata. Although amphisbaenians are known to have occurred in the Mesozoic1,2, their remains are rare and fragmentary. The oldest and most primitive known skull of an amphisbaenian is from the Eocene of North America3 and differs little from that of modern taxa4-9. A substantial structural map exists between this skull and that of the several possible sister groups8,10. No derived features uniquely linking amphisbaenians to any other group of the Squamata have been recognized, so the relationship of amphisbaenians is uncertain11,12. We report here on the late Cretaceous lizard-like amphisbaenian represented by well-preserved cranial and postcranial material from the Bayan Mandahu redbeds of the Gobi Desert, Inner Mongolia, China. This material documents the oldest and most primitive amphisbaenian yet known, and permits a re-evaluation of the relationship between the amphisbaenians and other squamates.
C1 UNIV CALGARY,DEPT BIOL SCI,CALGARY T2N 1N4,ALBERTA,CANADA.
   ACAD SINICA,INST VERTEBRATE PALEONTOL & PALEOANTHROPOL,BEIJING 10044,PEOPLES R CHINA.
C3 University of Calgary; Chinese Academy of Sciences; Institute of Vertebrate Paleontology & Paleoanthropology, CAS
RP WU, XC (corresponding author), ROYAL TYRRELL MUSEUM PALAEONTOL,BOX 7500,DRUMHELLER T0J 0Y0,AB,CANADA.
NR 26
TC 26
Z9 33
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 57
EP 59
DI 10.1038/366057a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700052
DA 2026-03-10
ER

PT J
AU GRESSENS, P
   HILL, JM
   GOZES, I
   FRIDKIN, M
   BRENNEMAN, DE
AF GRESSENS, P
   HILL, JM
   GOZES, I
   FRIDKIN, M
   BRENNEMAN, DE
TI GROWTH-FACTOR FUNCTION OF VASOACTIVE-INTESTINAL-PEPTIDE IN WHOLE CULTURED MOUSE EMBRYOS
SO NATURE
LA English
DT Article
ID sympathetic neuroblasts; neurotrophic action; regulates mitosis; rat-brain; polypeptide; antagonist; survival; vip; differentiation; quantitation
AB FACTORS controlling central nervous system (CNS) growth immediately after neurulation are mostly unknown. Vasoactive intestinal peptide (VIP) receptors are widely distributed in the embryonic nervous system1,2, and VIP has trophic and mitogenic properties3,4 on embryonic neural tissues but inhibits growth5 and mitosis in certain tumours6. To address the potential effects of VIP on embryonic growth, we used whole postimplantation embryo cultures7,8. After a 4-h incubation, VIP stimulated growth, increasing somite number, embryonic volume, DNA and protein content, and number of cells in S-phase. A VIP antagonist9,10 substantially inhibited these VIP-mediated increments in growth. The VIP antagonist completely suppressed VIP-stimulated mitosis in the CNS while decreasing the same. in non-neuronal tissues by 38%. In vitro autoradiography revealed GTP-sensitive and GTP-insensitive VIP receptors which were differentially regulated in VIP antagonist-treated embryos. The present study suggests that VIP acts as a growth factor on early postimplantation embryos through multiple VIP receptors that exhibit tissue-specific responses.
C1 NICHHD, DEV NEUROBIOL LAB, BETHESDA, MD 20892 USA.
   TEL AVIV UNIV, DEPT CHEM PATHOL, IL-69978 TEL AVIV, ISRAEL.
   WEIZMANN INST SCI, DEPT ORGAN CHEM, IL-76100 REHOVOT, ISRAEL.
C3 National Institutes of Health (NIH) - USA; NIH Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD); Tel Aviv University; Weizmann Institute of Science
RP GRESSENS, P (corresponding author), NINCDS, EXPTL NEUROPATHOL LAB, BETHESDA, MD 20892 USA.
NR 33
TC 269
Z9 285
U1 0
U2 9
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 155
EP 158
DI 10.1038/362155a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800059
PM 8383805
DA 2026-03-10
ER

PT J
AU MCFADDEN, PL
   BARTON, CE
   MERRILL, RT
AF MCFADDEN, PL
   BARTON, CE
   MERRILL, RT
TI DO VIRTUAL GEOMAGNETIC-POLES FOLLOW PREFERRED PATHS DURING GEOMAGNETIC REVERSALS
SO NATURE
LA English
DT Article
ID record
AB VIRTUAL geomagnetic poles (VGPs) recorded in sediments during reversals of the Earth's magnetic field show an apparent preference for two antipodal sectors of longitude1-3, not only in records of the same reversal from different sites, but also in records of different reversals. If preferred bands really have persisted from one reversal to the next, this would imply that the mantle exerts a significant control over the reversal process4. Here we analyse the available database of reversal records from the past 12 Myr, using a statistical test specifically designed to test the hypothesis of two preferred antipodal longitudinal bands. Our analysis shows that the records, taken as a group of independent observations, do show an overall preference for two antipodal longitudinal bands. However, the site longitudes are also strongly grouped5, and a comparison of the transitional VGP longitudes with site longitudes shows an unlikely grouping under the hypothesis of a genuine geographical preference for transitional VGPs. We conclude that it is premature to accept the hypothesis of mantle control over the core during geomagnetic reversals.
C1 UNIV WASHINGTON,GEOPHYS PROGRAM AK50,SEATTLE,WA 98195.
C3 University of Washington; University of Washington Seattle
RP MCFADDEN, PL (corresponding author), AUSTRALIAN GEOL SURVEY ORG,GPO BOX 378,CANBERRA,ACT,AUSTRALIA.
NR 13
TC 65
Z9 66
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 342
EP 344
DI 10.1038/361342a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000053
DA 2026-03-10
ER

PT J
AU MEDVINSKY, AL
   SAMOYLINA, NL
   MULLER, AM
   DZIERZAK, EA
AF MEDVINSKY, AL
   SAMOYLINA, NL
   MULLER, AM
   DZIERZAK, EA
TI AN EARLY PRE-LIVER INTRA-EMBRYONIC SOURCE OF CFU-S IN THE DEVELOPING MOUSE
SO NATURE
LA English
DT Article
ID hematopoietic stem-cells; colony-forming cells; yolk-sac; growth-factor; c-kit; ontogeny; origin; ligand; precursors; expression
AB IT is widely accepted that during murine embryogenesis, totipotent haematopoietic stem cells first originate in the yolk sac, then migrate to the fetal liver and finally colonize the bone marrow shortly before birth1,2. This view is based on in vitro studies showing that yolk sac cells can differentiate into various haematopoietic lineages1,3-7 and in vivo studies showing that yolk sac contains spleen colony-forming units (CFU-S) beginning at day 8 of gestation1. However, some investigators have failed to find statistically significant numbers of CFU-S arising from day 9 yolk sac3,8-11 and, although one group reported that yolk sac could repopulate the haematopoietic system of W mutant mice2, others have failed to confirm yolk sac-derived repopulation of adults3,12. In the avian and amphibian systems, the yolk sac gives rise only to early, transitory haematopoiesis whereas the definitive adult haematopoietic stem cells in these vertebrates are derived from the mesodermal region containing the dorsal aorta13-17. Because this analogous area of the mouse embryo has not been previously examined for haematopoietic activity, we directly compared the CFU-S activity of the aorta, gonad, mesonephros (AGM) region with the yolk sac and fetal liver during embryogenesis. Here we report that this intra-embryonic AGM region contains CFU-S activity at a higher frequency than that in embryonic yolk sac and that such activity appears in the AGM region before the fetal liver.
C1 NATL INST MED RES,LONDON NW7 1AA,ENGLAND.
C3 MRC National Institute for Medical Research
RP MEDVINSKY, AL (corresponding author), NATL RES CTR HEMATOL,PHYSIOL HEMATOPOIESIS LAB,NOVOZYKOVSKY PR 4A,MOSCOW 125167,RUSSIA.
NR 33
TC 408
Z9 472
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 64
EP 67
DI 10.1038/364064a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800058
PM 8316298
DA 2026-03-10
ER

PT J
AU FORCADA, ML
   MATE, CM
AF FORCADA, ML
   MATE, CM
TI MOLECULAR LAYERING DURING EVAPORATION OF ULTRATHIN LIQUID-FILMS
SO NATURE
LA English
DT Article
ID dynamics; surface; scale; drops
AB DYNAMICAL processes in very thin liquid films play a critical role in phenomena such as lubrication, wetting, spreading and emulsions, but these dynamics remain poorly understood at the molecular level. Heslot et al.1-5 observed molecular layering effects in a spreading liquid droplet, which they interpreted in terms of flow anomalies. Here we report that evaporation dynamics can also lead to the formation of distinct molecular layers in a thin liquid film. We use ellipsometry to follow the evolution in time of the thickness profile of a film of tetrakis(2-ethylhexoxy)silane deposited on silicon wafers. From an initially smooth gradient, we observe the formation of molecular steps 10 angstrom in height. The evaporation rate shows an oscillatory dependence on film thickness, leading us to conclude that layering results from faster evaporation of incomplete layers relative to complete layers.
C1 UNIV ALACANT,DEPT FIS APLICADA,E-03071 ALACANT,SPAIN.
C3 Universitat d'Alacant
RP FORCADA, ML (corresponding author), IBM CORP,ALMADEN RES CTR,DIV RES,650 HARRY RD,SAN JOSE,CA 95120, USA.
NR 13
TC 31
Z9 34
U1 0
U2 16
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 527
EP 529
DI 10.1038/363527a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900043
DA 2026-03-10
ER

PT J
AU TROUCHE, D
   GRIGORIEV, M
   LENORMAND, JL
   ROBIN, P
   LEIBOVITCH, SA
   SASSONECORSI, P
   HARELBELLAN, A
AF TROUCHE, D
   GRIGORIEV, M
   LENORMAND, JL
   ROBIN, P
   LEIBOVITCH, SA
   SASSONECORSI, P
   HARELBELLAN, A
TI REPRESSION OF C-FOS PROMOTER BY MYOD ON MUSCLE-CELL DIFFERENTIATION
SO NATURE
LA English
DT Article
ID epidermal growth-factor; serum response element; dna-binding; 12-o-tetradecanoyl phorbol-13-acetate; myogenic differentiation; transcription factor; myc homology; fibroblasts; expression; myoblasts
AB TERMINAL differentiation and cell proliferation are in many cases, as in muscle cells1, mutually exclusive processes. While differentiating myoblasts are withdrawn from the cell cycle2, myogenesis is inhibited by some mitogens and overexpression of some oncogenes3,4, including proto-oncogene c-fos5 (which expresses a growth-associated protein constituting the regulatory factor AP-1 in conjunction with c-Jun6,7).  MyoD, a muscle-specific transcription factor of the basic helix-loop-helix family8,9, acts at both levels because it triggers a muscle differentiation programme in non-muscle cells10-12, and induces a complete block of cell proliferation13,14. Antagonistic interaction between MyoD and c-Jun has been demonstrated15. We here show that c-fos expression greatly decreases upon muscle cell differentiation, concomitant with MyoD-induced activity. We have identified a MyoD-binding site overlapping with the serum-responsive element in the c-fos promoter. We demonstrate that MyoD can act as a negative regulator for c-fos transcription by blocking serum responsiveness through this binding site. These data suggest that the MyoD negative effect on cell growth could be partly mediated by transcriptional inactivation of growth-responsive genes.
C1 INST GUSTAVE ROUSSY,ONCOL MOLEC LAB,CNRS,URA 1158,F-94805 VILLEJUIF,FRANCE.
   INST CHIM BIOL,GENET MOLEC EUCARYOTES LAB,STRASBOURG,FRANCE.
C3 Centre National de la Recherche Scientifique (CNRS); UNICANCER; Gustave Roussy
NR 31
TC 96
Z9 100
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 79
EP 82
DI 10.1038/363079a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200064
PM 8386804
DA 2026-03-10
ER

PT J
AU JACOBSON, MD
   BURNE, JF
   KING, MP
   MIYASHITA, T
   REED, JC
   RAFF, MC
AF JACOBSON, MD
   BURNE, JF
   KING, MP
   MIYASHITA, T
   REED, JC
   RAFF, MC
TI BCL-2 BLOCKS APOPTOSIS IN CELLS LACKING MITOCHONDRIAL-DNA
SO NATURE
LA English
DT Article
ID membrane protein; survival; death; translocation; fibroblasts; expression; antibody; product; lines
AB WHEN the mammalian proto-oncogene bcl-2 is overexpressed it can protect various types of cells both from normal and from experimentally induced apoptosis1-6, but the molecular mechanisms involved are unknown. Although the Bcl-2 protein is membrane-associated7-10, its subcellular location is controversial: two studies have suggested that it is mainly associated with the nuclear envelope and endoplasmic reticulum8,10, whereas another study has suggested that it is mainly located in the inner mitochondrial membrane9. The latter study has suggested that Bcl-2 might protect cells from apoptosis by altering mitochondrial function and that mitochondria may be involved in apoptosis9,11. Here we report that human mutant cell lines that lack mitochondrial DNA (mtDNA), and therefore do not have a functional respiratory chain, can still be induced to die by apoptosis, and that they can be protected from apoptosis by the overexpression of bcl-2, suggesting that neither apoptosis nor the protective effect of bcl-2 depends on mitochondrial respiration. We also show that the Bcl-2 protein in overexpressing cells is associated with the nuclear envelope and endoplasmic reticulum, as well as with mitochondria.
C1 COLUMBIA UNIV COLL PHYS & SURG,DEPT NEUROL,NEW YORK,NY 10032.
   LA JOLLA CANC RES FDN,INST CANC RES,LA JOLLA,CA 92037.
C3 Columbia University; Sanford Burnham Prebys Medical Discovery Institute
RP JACOBSON, MD (corresponding author), UNIV LONDON UNIV COLL,DEPT BIOL,MRC,DEV NEUROBIOL PROGRAMME,MEDAWAR BLDG,LONDON WC1E 6BT,ENGLAND.
NR 32
TC 743
Z9 794
U1 0
U2 18
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 365
EP 369
DI 10.1038/361365a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000062
PM 8381212
DA 2026-03-10
ER

PT J
AU ALLEY, RB
   MEESE, DA
   SHUMAN, CA
   GOW, AJ
   TAYLOR, KC
   GROOTES, PM
   WHITE, JWC
   RAM, M
   WADDINGTON, ED
   MAYEWSKI, PA
   ZIELINSKI, GA
AF ALLEY, RB
   MEESE, DA
   SHUMAN, CA
   GOW, AJ
   TAYLOR, KC
   GROOTES, PM
   WHITE, JWC
   RAM, M
   WADDINGTON, ED
   MAYEWSKI, PA
   ZIELINSKI, GA
TI ABRUPT INCREASE IN GREENLAND SNOW ACCUMULATION AT THE END OF THE YOUNGER DRYAS EVENT
SO NATURE
LA English
DT Article
ID ice cores; climate; bp
AB THE warming at the end of the last glaciation was characterized by a series of abrupt returns to glacial climate, the best-known of which is the Younger Dryas event1. Despite much study of the causes of this event and the mechanisms by which it ended, many questions remain unresolved1. Oxygen isotope data from Greenland ice cores2-4 suggest that the Younger Dryas ended abruptly, over a period of about 50 years; dust concentrations2,4 in these cores show an even more rapid transition (less-than-or-similar-to 20 years). This extremely short timescale places severe constraints on the mechanisms underlying the transition. But dust concentrations can reflect subtle changes in atmospheric circulation, which need not be associated with a large change in climate. Here we present results from a new Greenland ice core (GISP2) showing that snow accumulation doubled rapidly from the Younger Dryas event to the subsequent Preboreal interval, possibly in one to three years. We also find that the accumulation-rate change from the Oldest Dryas to the Bolling/Allerod warm period was large and abrupt. The extreme rapidity of these changes in a variable that directly represents regional climate implies that the events at the end of the last glaciation may have been responses to some kind of threshold or trigger in the North Atlantic climate system.
C1 PENN STATE UNIV,DEPT GEOSCI,UNIV PK,PA 16802.
   USA,COLD REG RES & ENGN LAB,SNOW & ICE BRANCH,HANOVER,NH 03755.
   UNIV NEVADA,DESERT RES INST,RENO,NV 89506.
   UNIV WASHINGTON,QUATERNARY ISOTOPE LAB,SEATTLE,WA 98195.
   UNIV COLORADO,INST ARCTIC & ALPINE RES,BOULDER,CO 80309.
   UNIV BUFFALO,DEPT PHYS,AMHERST,NY 14260.
   UNIV WASHINGTON,GEOPHYS PROGRAM,SEATTLE,WA 98195.
   UNIV NEW HAMPSHIRE,INST STUDY EARTH OCEANS & SPACE,GLACIER RES GRP,DURHAM,NH 03824.
C3 Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; United States Department of Defense; United States Army; U.S. Army Corps of Engineers; U.S. Army Engineer Research & Development Center (ERDC); Cold Regions Research & Engineering Laboratory (CRREL); Nevada System of Higher Education (NSHE); University of Nevada Reno; Desert Research Institute NSHE; University of Washington; University of Washington Seattle; University of Colorado System; University of Colorado Boulder; State University of New York (SUNY) System; University at Buffalo, SUNY; University of Washington; University of Washington Seattle; University System Of New Hampshire; University of New Hampshire
RP ALLEY, RB (corresponding author), PENN STATE UNIV,CTR EARTH SYST SCI,UNIV PK,PA 16802, USA.
NR 27
TC 875
Z9 994
U1 4
U2 250
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 527
EP 529
DI 10.1038/362527a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300049
DA 2026-03-10
ER

PT J
AU YOU, GF
   SMITH, CP
   KANAI, Y
   LEE, WS
   STELZNER, M
   HEDIGER, MA
AF YOU, GF
   SMITH, CP
   KANAI, Y
   LEE, WS
   STELZNER, M
   HEDIGER, MA
TI CLONING AND CHARACTERIZATION OF THE VASOPRESSIN-REGULATED UREA TRANSPORTER
SO NATURE
LA English
DT Article
AB UREA is the principal end product of nitrogen metabolism in mammals1. Movement of urea across cell membranes was originally thought to occur by lipid-phase permeation, but recent studies have revealed the existence of specialized transporters with a low affinity for urea (K(m) > 200 mM)2. Here we report the isolation of a complementary DNA from rabbit renal medulla that encodes a 397-amino-acid membrane glycoprotein, UT2, with the functional characteristics of the vasopressin-sensitive urea transporter previously described in in vitro-perfused inner medullary collecting ducts3,4. UT2 is not homologous to any known protein and displays a unique pattern of hydrophobicity. Because of the central role of this transporter in fluid balance1,3-7 and nitrogen metabolism8, the study of this protein will provide important insights into the urinary concentrating mechanism and nitrogen balance.
C1 BRIGHAM & WOMENS HOSP,DEPT MED,DIV RENAL,75 FRANCIS ST,BOSTON,MA 02115.
   HARVARD UNIV,SCH MED,DEPT BIOL CHEM & MOLEC PHARMACOL,BOSTON,MA 02115.
C3 Harvard University; Harvard University Medical Affiliates; Brigham & Women's Hospital; Harvard University; Harvard Medical School
NR 33
TC 281
Z9 292
U1 0
U2 16
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 844
EP 847
DI 10.1038/365844a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100052
PM 8413669
DA 2026-03-10
ER

PT J
AU AJAYAN, PM
   EBBESEN, TW
   ICHIHASHI, T
   IIJIMA, S
   TANIGAKI, K
   HIURA, H
AF AJAYAN, PM
   EBBESEN, TW
   ICHIHASHI, T
   IIJIMA, S
   TANIGAKI, K
   HIURA, H
TI OPENING CARBON NANOTUBES WITH OXYGEN AND IMPLICATIONS FOR FILLING
SO NATURE
LA English
DT Article
AB CAPPED hollow carbon nanotubes1,2 can be modified into nanocomposite fibres by simultaneous opening of the caps (by heating in the presence of air and lead metal) and filling of the interior with an inorganic phase3. To generalize this approach, greater understanding is needed of the reaction mechanism between the tube caps and oxygen. Here we report that the oxidation of carbon nanotubes in air for short durations above about 700-degrees-C results in the etching away of the tube caps and the thinning of tubes through layer-by-layer peeling of the outer layers, starting from the cap region. The oxidation reaction follows an Arrhenius-type relation with an activation energy barrier of about 225 kJ mol-1 in air. Heating of closed nanotubes with an oxide (Pb3O4) in an inert atmosphere lowers the activation barrier for the reaction and opening of the tubes occurs at lower temperatures. Contrary to intuition, however, open tubes are much more difficult to fill with inorganic materials than in the one-step filling of tubes reported previously3. But various other experiments might be possible in the inner nano-cavities of the open tubes such as studies of catalysis and of low-dimensional chemistry and physics.
RP AJAYAN, PM (corresponding author), NEC CORP LTD, FUNDAMENTAL RES LAB, 34 MIYUKIGAOKA, TSUKUBA 305, JAPAN.
NR 9
TC 995
Z9 1139
U1 0
U2 365
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 522
EP 525
DI 10.1038/362522a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300047
DA 2026-03-10
ER

PT J
AU LARDER, BA
   KOHLI, A
   KELLAM, P
   KEMP, SD
   KRONICK, M
   HENFREY, RD
AF LARDER, BA
   KOHLI, A
   KELLAM, P
   KEMP, SD
   KRONICK, M
   HENFREY, RD
TI QUANTITATIVE DETECTION OF HIV-1 DRUG-RESISTANCE MUTATIONS BY AUTOMATED DNA-SEQUENCING
SO NATURE
LA English
DT Article
ID transcriptase
C1 APPL BIOSYST 850,FOSTER CITY,CA 94404.
   APPL BIOSYST LTD,WARRINGTON WA3 7PB,CHESHIRE,ENGLAND.
C3 Thermo Fisher Scientific; Applied Biosystems; Thermo Fisher Scientific; Applied Biosystems
RP LARDER, BA (corresponding author), WELLCOME FDN LTD,ANTIVIRAL THERAPEUT RES UNIT,LANGLEY COURT,BECKENHAM BR3 3BS,KENT,ENGLAND.
NR 7
TC 176
Z9 189
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 671
EP 673
DI 10.1038/365671a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600066
PM 8413632
DA 2026-03-10
ER

PT J
AU SIGMAN, DS
   CHEN, CB
   GORIN, MB
AF SIGMAN, DS
   CHEN, CB
   GORIN, MB
TI SEQUENCE-SPECIFIC SCISSION OF DNA BY RNAS LINKED TO A CHEMICAL NUCLEASE
SO NATURE
LA English
DT Article
ID 1,10-phenanthroline copper-ion; delta-1 crystallin gene; cleavage; conversion; site
C1 UNIV CALIF LOS ANGELES,DEPT CHEM & BIOCHEM,LOS ANGELES,CA 90024.
   UNIV CALIF LOS ANGELES,INST MOLEC BIOL,LOS ANGELES,CA 90024.
   UNIV PITTSBURGH,DEPT OPHTHALMOL,PITTSBURGH,PA 15213.
   UNIV PITTSBURGH,DEPT HUMAN GENET,PITTSBURGH,PA 15213.
   EYE & EAR INST,PITTSBURGH,PA 15213.
C3 University of California System; University of California Los Angeles; University of California System; University of California Los Angeles; Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh; Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh
RP SIGMAN, DS (corresponding author), UNIV CALIF LOS ANGELES,SCH MED,DEPT BIOL CHEM,LOS ANGELES,CA 90024, USA.
NR 24
TC 21
Z9 23
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 474
EP 475
DI 10.1038/363474a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800067
PM 7684825
DA 2026-03-10
ER

PT J
AU OHARA, SL
   STREETPERROTT, FA
   BURT, TP
AF OHARA, SL
   STREETPERROTT, FA
   BURT, TP
TI ACCELERATED SOIL-EROSION AROUND A MEXICAN HIGHLAND LAKE CAUSED BY PRE-HISPANIC AGRICULTURE
SO NATURE
LA English
DT Article
ID patzcuaro
AB THE severely degraded landscape of the volcanic highlands of central Mexico has been the focus of considerable debate1-5. Although it is widely believed that the Spanish encountered an almost pristine landscape in AD 1521 (refs 1-3), some archival and palaeolimnological studies have suggested that extensive land clearance began before European contact, during the Preclassic to Postclassic periods (approximately 3,500-350 C-14 yr before present, BP)5-11. Here we analyse sediment cores from Lake Patzcuaro, Michoacan (Fig. 1), to derive a quantitative estimate of variations in soil erosion in central Mexico since 4,000 yr BP. We identify three periods of accelerated erosion and conclude that erosion rates during both the late Preclassic/early Classic periods (2,500-1,200 yr BP) and the later Postclassic period (850-350 yr BP) were at least as high as those after the Spanish conquest. One implication of these results is that soil erosion caused by the Spanish introduction of plough agriculture was apparently no more severe than that associated with traditional agricultural methods; it is therefore questionable whether a return to traditional methods would have significant environmental benefits.
C1 ENVIRONM CHANGE UNIT,OXFORD OX1 3TB,ENGLAND.
   UNIV OXFORD,OXFORD OX1 3TB,ENGLAND.
C3 University of Oxford; University of Oxford
RP OHARA, SL (corresponding author), UNIV SHEFFIELD,DEPT GEOG,WESTERN BANK,SHEFFIELD S10 2TN,S YORKSHIRE,ENGLAND.
NR 30
TC 171
Z9 191
U1 0
U2 29
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 48
EP 51
DI 10.1038/362048a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600055
DA 2026-03-10
ER

PT J
AU SCHERLY, D
   NOUSPIKEL, T
   CORLET, J
   UCLA, C
   BAIROCH, A
   CLARKSON, SG
AF SCHERLY, D
   NOUSPIKEL, T
   CORLET, J
   UCLA, C
   BAIROCH, A
   CLARKSON, SG
TI COMPLEMENTATION OF THE DNA-REPAIR DEFECT IN XERODERMA-PIGMENTOSUM GROUP-G CELLS BY A HUMAN CDNA RELATED TO YEAST RAD2
SO NATURE
LA English
DT Article
ID saccharomyces-cerevisiae; nucleotide-sequence; gene; disorders; cloning
AB DEFECTS in human DNA repair proteins can give rise to the autosomal recessive disorders xeroderma pigmentosum (XP) and Cockayne's syndrome (CS), sometimes even together1-3. Seven XP and three CS complementation groups have been identified that are thought to be due to mutations in genes from the nucleotide excision repair pathway2,3. Here we isolate frog and human complementary DNAs that encode proteins resembling RAD2, a protein involved in this pathway in yeast4,5. Alignment of these three polypeptides, together with two other RAD2 related proteins6,7, reveals that their conserved sequences are largely confined to two regions. Expression of the human cDNA in vivo restores to normal the sensitivity to ultraviolet light and unscheduled DNA synthesis of lymphoblastoid celts from XP group G, but not CS group A. The XP-G correcting protein XPGC is generated from a messenger RNA of approximately 4 kilobases that is present in normal amounts in the XP-G cell line.
C1 UNIV GENEVA,MED CTR,DEPT MED BIOCHEM,CH-1211 GENEVA 4,SWITZERLAND.
C3 University of Geneva
RP SCHERLY, D (corresponding author), UNIV GENEVA,MED CTR,DEPT GENET & MICROBIOL,9 AVE CHAMPEL,CH-1211 GENEVA 4,SWITZERLAND.
NR 30
TC 205
Z9 216
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 182
EP 185
DI 10.1038/363182a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100054
PM 8483504
DA 2026-03-10
ER

PT J
AU ROBINSON, PJ
   SONTAG, JM
   LIU, JP
   FYKSE, EM
   SLAUGHTER, C
   MCMAHON, H
   SUDHOF, TC
AF ROBINSON, PJ
   SONTAG, JM
   LIU, JP
   FYKSE, EM
   SLAUGHTER, C
   MCMAHON, H
   SUDHOF, TC
TI DYNAMIN GTPASE REGULATED BY PROTEIN-KINASE-C PHOSPHORYLATION IN NERVE-TERMINALS
SO NATURE
LA English
DT Article
ID temperature-sensitive mutant; reversible blockage; intact synaptosm; membrane retrieval; drosophila; endocytosis; dephosphorylation; microtubules; shibire; release
AB DYNAMIN is a microtubule-binding protein with a microtubule-activated GTPase activity1-3. The gene encoding dynamin is mutated in shibire4,5, a Drosophila mutant defective in endocytosis in nerve terminals and other cells6-9. These observations place dynamin into two distinct functional contexts, suggesting roles in microtubule-based motility or in endocytosis. We report here that dynamin is identical to the neuronal phosphoprotein dephosphin (P96), originally identified by its stimulus-dependent dephosphorylation in nerve terminals10-13. Dynamin is a protein doublet of M(r) 94 and 96K arising by alternative splicing of its primary transcript. In the nerve terminal, both forms of dynamin are phosphorylated by protein kinase C (PKC) and are quantitatively dephosphorylated on excitation. In vitro, dynamin is also phosphorylated by casein kinase II which inhibits PKC phosphorylation. Phosphorylation by PKC but not by casein kinase II enhances the GTPase activity of dynamin 12-fold. The dynamins are therefore a group of nerve terminal phosphoproteins whose GTPase is regulated by phosphorylation in parallel with synaptic vesicle recycling. The regulation of dynamin GTPase could serve as the trigger for the rapid endocytosis of synaptic vesicles after exocytosis.
C1 UNIV TEXAS, SW MED CTR, DEPT MOLEC GENET, 5323 HARRY HINES BLVD, DALLAS, TX 75235 USA.
   JOHN HUNTER HOSP, ENDOCRINE UNIT, NEWCASTLE, NSW 2310, AUSTRALIA.
   UNIV TEXAS, SW MED CTR, HOWARD HUGHES MED INST, DALLAS, TX 75235 USA.
C3 University of Texas System; University of Texas Southwestern Medical Center; University of Texas Dallas; John Hunter Hospital; University of Texas System; University of Texas Dallas; Howard Hughes Medical Institute; University of Texas Southwestern Medical Center
NR 21
TC 266
Z9 280
U1 0
U2 8
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 163
EP 166
DI 10.1038/365163a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200049
PM 8371759
DA 2026-03-10
ER

PT J
AU STRAND, M
   PROLLA, TA
   LISKAY, RM
   PETES, TD
AF STRAND, M
   PROLLA, TA
   LISKAY, RM
   PETES, TD
TI DESTABILIZATION OF TRACTS OF SIMPLE REPETITIVE DNA IN YEAST BY MUTATIONS AFFECTING DNA MISMATCH REPAIR
SO NATURE
LA English
DT Article
ID 5' exonuclease activity; saccharomyces-cerevisiae; escherichia-coli; sequence; mutants
AB The genomes of all eukaryotes contain tracts of DNA in which a single base or a small number of bases is repeated. Expansions of such tracts have been associated with several human disorders including the fragile X syndrome1. In addition, simple repeats are unstable in certain forms of colorectal cancer, suggesting a defect in DNA replication or repair2-4. We show here that mutations in any three yeast genes involved in DNA mismatch repair (PMS1, MLH1 and MSH2) lead to 100- to 700-fold increases in tract instability, whereas mutations that eliminate the proof-reading function of DNA polymerases have little effect. The meiotic stability of the tracts is similar to the mitotic stability. Th results suggest that tract instability is associated with DNA polymerases slipping during replication, and that some types of colorectal cancer may reflect mutations in genes involved in DNA mismatch repair.
C1 UNIV N CAROLINA,CURRICULUM GENET & MOLEC BIOL,CHAPEL HILL,NC 27599.
   YALE UNIV,SCH MED,DEPT MOLEC BIOPHYS & BIOCHEM,NEW HAVEN,CT 06510.
   YALE UNIV,SCH MED,DEPT THERAPEUT RADIOL,NEW HAVEN,CT 06510.
C3 University of North Carolina; University of North Carolina Chapel Hill; Yale University; Yale University
RP STRAND, M (corresponding author), UNIV N CAROLINA,DEPT BIOL,CHAPEL HILL,NC 27599, USA.
NR 21
TC 981
Z9 1126
U1 0
U2 80
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 274
EP 276
DI 10.1038/365274a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100061
PM 8371783
DA 2026-03-10
ER

PT J
AU ANKLIN, M
   BARNOLA, JM
   BEER, J
   BLUNIER, T
   CHAPPELLAZ, J
   CLAUSEN, HB
   DAHLJENSEN, D
   DANSGAARD, W
   DEANGELIS, M
   DELMAS, RJ
   DUVAL, P
   FRATTA, M
   FUCHS, A
   FUHRER, K
   GUNDESTRUP, N
   HAMMER, C
   IVERSEN, P
   JOHNSEN, S
   JOUZEL, J
   KIPFSTUHL, J
   LEGRAND, M
   LORIUS, C
   MAGGI, V
   MILLER, H
   MOORE, JC
   OESCHGER, H
   OROMBELLI, G
   PEEL, DA
   RAISBECK, G
   RAYNAUD, D
   SCHOTTHVIDBERG, C
   SCHWANDER, J
   SHOJI, H
   SOUCHEZ, R
   STAUFFER, B
   STEFFENSEN, JP
   STIEVENARD, M
   SVEINBJORNSDOTTIR, A
   THORSTEINSSON, T
   WOLFF, EW
AF ANKLIN, M
   BARNOLA, JM
   BEER, J
   BLUNIER, T
   CHAPPELLAZ, J
   CLAUSEN, HB
   DAHLJENSEN, D
   DANSGAARD, W
   DEANGELIS, M
   DELMAS, RJ
   DUVAL, P
   FRATTA, M
   FUCHS, A
   FUHRER, K
   GUNDESTRUP, N
   HAMMER, C
   IVERSEN, P
   JOHNSEN, S
   JOUZEL, J
   KIPFSTUHL, J
   LEGRAND, M
   LORIUS, C
   MAGGI, V
   MILLER, H
   MOORE, JC
   OESCHGER, H
   OROMBELLI, G
   PEEL, DA
   RAISBECK, G
   RAYNAUD, D
   SCHOTTHVIDBERG, C
   SCHWANDER, J
   SHOJI, H
   SOUCHEZ, R
   STAUFFER, B
   STEFFENSEN, JP
   STIEVENARD, M
   SVEINBJORNSDOTTIR, A
   THORSTEINSSON, T
   WOLFF, EW
TI CLIMATE INSTABILITY DURING THE LAST INTERGLACIAL PERIOD RECORDED IN THE GRIP ICE CORE
SO NATURE
LA English
DT Article
ID greenland; cycle; sheet
AB Isotope and chemical analyses of the GRIP ice core from Summit, central Greenland, reveal that climate in Greenland during the last interglacial period was characterized by a series of severe cold periods, which began extremely rapidly and lasted from decades to centuries. As the last interglacial seems to have been slightly warmer than the present one, its unstable climate raises questions about the effects of future global warming.
NR 41
TC 534
Z9 586
U1 1
U2 135
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 203
EP 207
DI 
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300046
DA 2026-03-10
ER

PT J
AU DAY, ML
   PICKERING, SJ
   JOHNSON, MH
   COOK, DI
AF DAY, ML
   PICKERING, SJ
   JOHNSON, MH
   COOK, DI
TI CELL-CYCLE CONTROL OF A LARGE-CONDUCTANCE K+-CHANNEL IN MOUSE EARLY EMBRYOS
SO NATURE
LA English
DT Article
ID potassium channels; improved culture; calcium current; lymphocyte-t; proliferation; cleavage; proteins; invitro
AB THERE have been few investigations into the role of ion channels in mammalian early embryonic development1-4, despite studies showing that changes in ion channel activity accompany the early embryonic development of non-mammalian species5-7 and the proliferation of mammalian cells8-12. Here we report that a large-conductance, voltage-activated K+ channel is active in unfertilized mouse oocytes but is rarely observed in later embryos. The channel activity is linked to the cell cycle, being active throughout M and G1 phases, and switching off during the G1-to-S transition. These changes in channel activity are accompanied by corresponding shifts in membrane potential. Inactivation of the channel during S/G2 can be prevented by exposing the oocytes to dibutyryl cyclic AMP or forskolin, an activator of adenylyl cyclase. Inhibition of protein synthesis with puromycin did not prevent inactivation of the channel at the end of G1 or its subsequent reactivation at the end of G2, indicating that the channel activity is not regulated by mitosis-promoting factor or cyclins.
C1 UNIV SYDNEY, DEPT PHYSIOL, SYDNEY, NSW 2006, AUSTRALIA.
   UNIV CAMBRIDGE, DEPT ANAT, CAMBRIDGE CB2 3DY, ENGLAND.
C3 University of Sydney; University of Cambridge
NR 30
TC 121
Z9 132
U1 0
U2 3
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 560
EP 562
DI 10.1038/365560a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100059
PM 8413614
DA 2026-03-10
ER

PT J
AU PESSI, A
   BIANCHI, E
   CRAMERI, A
   VENTURINI, S
   TRAMONTANO, A
   SOLLAZZO, M
AF PESSI, A
   BIANCHI, E
   CRAMERI, A
   VENTURINI, S
   TRAMONTANO, A
   SOLLAZZO, M
TI A DESIGNED METAL-BINDING PROTEIN WITH A NOVEL FOLD
SO NATURE
LA English
DT Article
ID 3-dimensional structure; crystal-structure; denovo design; light chain; site; conformation; expression
AB A MAJOR challenge in protein design is to create stable scaffolds into which tailored functions can be introduced. Here we present the design, synthesis and characterization of a 61-residue all-beta protein: the minibody. We used a portion of the heavy chain variable domain of an immunoglobulin as a template, obtaining a molecule with a novel beta-sheet scaffold and two regions corresponding to the hypervariable loops H1 and H2. To exploit the potential for creating functional centres in the minibody, we engineered a metal-binding site into it. This site is formed by one histidine in H1 and two in H2. The protein is folded, compact and able to bind metal, thus representing the first designed beta-protein with a novel fold and a tailored function. By randomizing the sequence of the hypervariable loops, we are using the minibody scaffold to construct a conformationally constrained peptide library displayed on phage.
C1 IST RIC BIOL MOLEC P ANGELETTI, DEPT GENET, VIA PONTINA KM 306, I-00040 POMEZIA, ITALY.
   IST RIC BIOL MOLEC P ANGELETTI, DEPT BIOCHEM, I-00040 POMEZIA, ITALY.
   IST RIC BIOL MOLEC P ANGELETTI, DEPT BIOCOMP, I-00040 POMEZIA, ITALY.
NR 24
TC 191
Z9 233
U1 0
U2 20
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 367
EP 369
DI 10.1038/362367a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600069
PM 8455724
DA 2026-03-10
ER

PT J
AU SEKIDO, N
   MUKAIDA, N
   HARADA, A
   NAKANISHI, I
   WATANABE, Y
   MATSUSHIMA, K
AF SEKIDO, N
   MUKAIDA, N
   HARADA, A
   NAKANISHI, I
   WATANABE, Y
   MATSUSHIMA, K
TI PREVENTION OF LUNG REPERFUSION INJURY IN RABBITS BY A MONOCLONAL-ANTIBODY AGAINST INTERLEUKIN-8
SO NATURE
LA English
DT Article
ID ischemia-reperfusion; vascular injury; lymphocytes-t; neutrophil; leukotriene-b4; purification; depletion; peptide; binding; model
AB RE-ESTABLISHING blood flow to ischaemic tissues causes greater injury than that induced during the ischaemic period1,2. This type of tissue injury, reperfusion injury, is involved in frostbite, multiple organ failure after hypovolaemia and in myocardial infarction1. Depletion of neutrophils alleviates reperfusion injury, implying a causal role of neutrophil infiltration3,4. Among members of the recently discovered family of chemotactic cytokines (chemokines)5-8, interleukin-8 (IL-8)5,9-13 is a major neutrophil chemotactic and activating factor produced by various types of human cells. We investigated its pathophysiological role in a rabbit model of a lung reperfusion injury. Reperfusion of ischaemic lung caused neutrophil infiltration and destruction of pulmonary structure, as well as local production of IL-8. Furthermore, the administration of a neutralizing monoclonal antibody against IL-8 prevented neutrophil infiltration and tissue injury, proving a causal role of locally produced IL-8 in this model.
C1 KANAZAWA UNIV,SCH MED,CANC RES INST,DEPT PHARMACOL,13-1 TAKARA MACHI,KANAZAWA,ISHIKAWA 920,JAPAN.
   KANAZAWA UNIV,SCH MED,DEPT PATHOL 1,KANAZAWA,ISHIKAWA 920,JAPAN.
   KANAZAWA UNIV,SCH MED,DEPT HYG,KANAZAWA,ISHIKAWA 920,JAPAN.
   KANAZAWA UNIV,SCH MED,DEPT SURG 1,KANAZAWA,ISHIKAWA 920,JAPAN.
C3 Kanazawa University; Kanazawa University; Kanazawa University; Kanazawa University
NR 31
TC 470
Z9 586
U1 0
U2 20
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 654
EP 657
DI 10.1038/365654a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600061
PM 8413628
DA 2026-03-10
ER

PT J
AU CROMMIE, MF
   LUTZ, CP
   EIGLER, DM
AF CROMMIE, MF
   LUTZ, CP
   EIGLER, DM
TI IMAGING STANDING WAVES IN A 2-DIMENSIONAL ELECTRON-GAS
SO NATURE
LA English
DT Article
ID scanning tunneling microscope; surface-states; local density; single atoms; photoemission; spectroscopy; au(111); cu(111); metal
AB ELECTRONS occupying surface states on the close-packed surfaces of noble metals form a two-dimensional nearly free electron gas1-3. These states can be probed using the scanning tunnelling microscope (STM), providing a unique opportunity to study the local properties of electrons in low-dimensional systems4. Here we report the direct observation of standing-wave patterns in the local density of states of the Cu(111) surface using the STM at low temperature. These spatial oscillations are quantum-mechanical interference patterns caused by scattering of the two-dimensional electron gas off step edges and point defects. Analysis of the spatial oscillations gives an independent measure of the surface state dispersion, as well as insight into the interaction between surface-state electrons and scattering sites on the surface.
RP CROMMIE, MF (corresponding author), IBM CORP,ALMADEN RES CTR,DIV RES,650 HARRY RD,SAN JOSE,CA 95120, USA.
NR 14
TC 1107
Z9 1227
U1 3
U2 414
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 524
EP 527
DI 10.1038/363524a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900042
DA 2026-03-10
ER

PT J
AU KIRSCH, J
   WOLTERS, I
   TRILLER, A
   BETZ, H
AF KIRSCH, J
   WOLTERS, I
   TRILLER, A
   BETZ, H
TI GEPHYRIN ANTISENSE OLIGONUCLEOTIDES PREVENT GLYCINE RECEPTOR CLUSTERING IN SPINAL NEURONS
SO NATURE
LA English
DT Article
ID nicotinic acetylcholine-receptors; gamma-aminobutyric acid; monoclonal-antibody; postsynaptic membrane; central synapses; protein; tubulin; localization; polypeptide; complex
AB EACH neuron in the mammalian brain carries many postsynaptic membrane specializations containing high densities of receptors that mediate signal transduction upon neurotransmitter release from the apposed nerve terminal1. Little is known about the mechanisms by which receptors are transported to and anchored at postsynaptic sites, but extracellular2 as well as intracellular3 components may be involved. Ultrastructural studies have shown that the peripheral membrane protein gephyrin4, Which co-purifies with the postsynaptic inhibitory glycine receptor (GlyR) upon affinity chromatography5,6, is situated on the cytoplasmic face of glycinergic postsynaptic membranes7-9. Moreover, gephyrin binds with high affinity to polymerized tubulin and has been postulated to link the GlyR to the subsynaptic cytoskeleton10. Here we report that treatment of rat spinal neurons in culture with gephyrin antisense oligonucleotides prevents the formation of GlyR clusters in the dendritic plasma membrane. Thus, gephyrin is essential for localizing the GlyR to presumptive postsynaptic plasma membrane specializations.
C1 MAX PLANCK INST BRAIN RES,DEPT NEUROCHEM,DEUTSCHORDENSTR 46,D-60528 FRANKFURT,GERMANY.
   INST PASTEUR,DEPT BIOTECHNOL,INSERM,U261,F-750 PARIS 15,FRANCE.
C3 Max Planck Society; Institut National de la Sante et de la Recherche Medicale (Inserm)
NR 30
TC 379
Z9 422
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 23
PY 1993
VL 366
IS 6457
BP 745
EP 748
DI 10.1038/366745a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MN264
UT WOS:A1993MN26400029
PM 8264797
DA 2026-03-10
ER

PT J
AU HART, AC
   KRAMER, H
   ZIPURSKY, SL
AF HART, AC
   KRAMER, H
   ZIPURSKY, SL
TI EXTRACELLULAR DOMAIN OF THE BOSS TRANSMEMBRANE LIGAND ACTS AS AN ANTAGONIST OF THE SEV RECEPTOR
SO NATURE
LA English
DT Article
ID tyrosine-kinase receptor; drosophila retina; sevenless protein; growth-factor; cell fate; si-locus; bride; gene; encodes; mouse
AB THE fate of the R7 photoreceptor cell in the Drosophila compound eye is established by a specific inductive interaction between the R8 photoreceptor neuron and the R7 precursor cell1. This induction is mediated by two cell-surface proteins: the ligand, bride of sevenless2 (boss), and sevenless (sev), a tyrosine-kinase receptor3-5 The structure of boss is unique for a ligand of a tyrosine-kinase receptor. It contains a large extracellular domain, seven transmembrane segments, and a carboxy-terminal cytoplasmic tail6,7.  Here we report that: (1) boss activates tyrosine phosphorylation of the sev receptor; (2) the seven transmembrane domain of boss is necessary for its function; and (3) a soluble form of boss acts as an antagonist of the sev receptor both in vivo and in vitro.
C1 UNIV CALIF LOS ANGELES,INST MOLEC BIOL,DEPT BIOL CHEM,HOWARD HUGHES MED INST,LOS ANGELES,CA 90024.
C3 University of California System; University of California Los Angeles; Howard Hughes Medical Institute
NR 21
TC 39
Z9 41
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 732
EP 736
DI 10.1038/361732a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900059
PM 7680109
DA 2026-03-10
ER

PT J
AU BRESSLER, SL
   COPPOLA, R
   NAKAMURA, R
AF BRESSLER, SL
   COPPOLA, R
   NAKAMURA, R
TI EPISODIC MULTIREGIONAL CORTICAL COHERENCE AT MULTIPLE FREQUENCIES DURING VISUAL TASK-PERFORMANCE
SO NATURE
LA English
DT Article
ID oscillatory neuronal responses; cortex; cat; synchronization; monkey; patterns; striate
AB THE way in which the brain integrates fragmentary neural events at multiple locations to produce unified perceptual experience and behaviour is called the binding problem1,2. Binding has been proposed to involve correlated activity at different cortical sites during perceptuomotor behaviour3-5, particularly by synchronization of narrow-band oscillations in the gamma-frequency range (30-80 Hz)6,7. In the rabbit olfactory system, inhalation induces increased gamma-correlation between sites in olfactory bulb and cortex8. In the cat visual system, coherent visual stimuli increase gamma-correlation between sites in both the same and different visual cortical areas9-12. In monkeys, some groups have found that gamma-ocillations transiently synchronize within striate cortex13, superior temporal sulcus14 and somatosensorimotor cortex15,16. Others have report that visual stimuli produce increased broad-band power, but not gamma-oscillations, in several visual cortical areas17,18. But the absence of narrow-band oscillations in itself does not disprove inter-regional synchronization, which may be a broad-band phenomenon. We now describe episodes of increased broad-band coherence among local field potentials from sensory, motor and higher-order cortical sites of macaque monkeys performing a visual discrimination task. Widely distributed sites become coherent without involving other interverting sites. Spatially selective multiregional cortical binding, in the form of broad-band synchronization, may thus play a role in primate perceptuomotor behaviour.
C1 ST ELIZABETH HOSP,NIMH,CTR NEUROSCI,WASHINGTON,DC 20032.
   NIMH,NEUROPSYCHOL LAB,BETHESDA,MD 20892.
C3 National Institutes of Health (NIH) - USA; NIH National Institute of Mental Health (NIMH); National Institutes of Health (NIH) - USA; NIH National Institute of Mental Health (NIMH)
RP BRESSLER, SL (corresponding author), FLORIDA ATLANTIC UNIV,CTR COMPLEX SYST,BOCA RATON,FL 33431, USA.
NR 26
TC 393
Z9 426
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 153
EP 156
DI 10.1038/366153a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600056
PM 8232553
DA 2026-03-10
ER

PT J
AU FOULKES, NS
   SCHLOTTER, F
   PEVET, P
   SASSONECORSI, P
AF FOULKES, NS
   SCHLOTTER, F
   PEVET, P
   SASSONECORSI, P
TI PITUITARY-HORMONE FSH DIRECTS THE CREM FUNCTIONAL SWITCH DURING SPERMATOGENESIS
SO NATURE
LA English
DT Article
ID golden-hamsters; gene; transcription; sequence
AB THE CREM (cyclic AMP-responsive element modulator) gene encodes multiple regulators of the cAMP-transcriptional response by alternative splicing1. A developmental switch in CREM expression occurs during spermatogenesis, whereby CREM function is converted from an antagonist to an activator (CREMtau; ref. 2) which accumulates to extremely high levels from the premeiotic spermatocyte stage onwards. To define the physiological mechanisms controlling the CREM developmental switch, we have hypophysectomized rats and observed the extinction of CREMtau expression in testis, thereby demonstrating a central role of the pituitary-hypothalamic axis. We then used the seasonal-dependent modulation of spermatogenesis in hamsters to dissect the hormonal programme controlling this developmental process. By this approach, combined with direct administration of pituitary-derived hormones, we have established that follicle-stimulating hormone (FSH) is responsible for the CREM switch. FSH appears to regulate CREM expression by alternative polyadenylation, which results in a dramatic enhancement of transcript stability.
C1 CNRS, URA 1332, F-67000 STRASBOURG, FRANCE.
C3 Centre National de la Recherche Scientifique (CNRS)
RP SASSONECORSI, P (corresponding author), FAC MED STRASBOURG, CNRS, GENET MOLEC EUCARYOTES LAB, INSERM, U184, F-67085 STRASBOURG, FRANCE.
NR 19
TC 238
Z9 246
U1 0
U2 3
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 264
EP 267
DI 10.1038/362264a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600062
PM 7681549
DA 2026-03-10
ER

PT J
AU SEEMAN, P
   GUAN, HC
   VANTOL, HHM
AF SEEMAN, P
   GUAN, HC
   VANTOL, HHM
TI DOPAMINE D4 RECEPTORS ELEVATED IN SCHIZOPHRENIA
SO NATURE
LA English
DT Article
ID positron emission tomography; human-brain; antipsychotic-drugs; high-affinity; binding; neuroleptics; d2-receptors; population; nucleotide; conversion
AB ALTHOUGH the biological basis of schizophrenia is not known, possible causes include genetic defects, viruses1, amines2, brain structure and metabolism3-5, neuroreceptors6-8, and G proteins9. The hypothesis of dopamine overactivity in schizophrenia is based on the fact that neuroleptics block dopamine D2 receptors in direct relation to their clinical antipsychotic potencies10,11. Moreover, dopamine D2 or D2-like receptors are elevated in postmortem schizophrenia brain tissue8,12,13. This elevation, however, is only found in vivo using [C-11]methylspiperone14 but not [C-11]raclopride15. The dopamine D4 receptor gene16 has not yet been excluded in schizophrenia because the 21 gene variants17 of D4 have not yet been tested. Because the link between D1 and D2 receptors is reduced in schizophrenia tissue9, we tested whether one component of this link was sensitive to guanine nucleotide. We report here that the binding of [H-3]raclopride to D2 receptors in schizophrenia was not sensitive to guanine nucleotide. This finding permitted analysis of data12,18 on the binding of [H-3]emonapride to the D2, D3 and D4 receptors. We conclude that the combined density of D2 and D3 receptors (labelled by [H-3]raclopride16,19) is increased by only 10% in schizophrenia brain, as found by Farde et al.15, but that it is the density of dopamine D4 receptors which is sixfold elevated in schizophrenia. These findings resolve the apparent discrepancy, mentioned above, wherein the density of [C-11]methylspiperone-labelled sites14 (D2, D3 and D4), but not that of [C-11]raclopride-labelled sites15 (D2 and D3), was found elevated in the schizophrenia striatum.
C1 UNIV TORONTO,DEPT PSYCHIAT,TORONTO M5S 1A8,ONTARIO,CANADA.
   CLARKE INST PSYCHIAT,MOLEC NEUROBIOL LAB,TORONTO M5T 1R8,ONTARIO,CANADA.
C3 University of Toronto; University of Toronto; Centre for Addiction & Mental Health - Canada
RP SEEMAN, P (corresponding author), UNIV TORONTO,DEPT PHARMACOL,MED SCI BLDG,TORONTO M5S 1A8,ONTARIO,CANADA.
NR 32
TC 618
Z9 670
U1 4
U2 38
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 441
EP 445
DI 10.1038/365441a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300056
PM 8413587
DA 2026-03-10
ER

PT J
AU AREVALO, JH
   TAUSSIG, MJ
   WILSON, IA
AF AREVALO, JH
   TAUSSIG, MJ
   WILSON, IA
TI MOLECULAR-BASIS OF CROSS-REACTIVITY AND THE LIMITS OF ANTIBODY-ANTIGEN COMPLEMENTARITY
SO NATURE
LA English
DT Article
AB TWO major unanswered questions concerning the specificity of antibodies are: how do structurally different antigens bind with high affinity to the same antibody, and what are the limits of the antibody combining site complementarity and flexibility that contribute to such crossreactivity? We report here a comparative analysis of the X-ray structures of five conformationally different steroids in complex with the Fab' fragment of an anti-progesterone antibody DB3 at 2.7 angstrom. This antibody is unable to complement completely the shape of the hydrophobic antigen so that crossreactivity occurs with other ligands without major structural rearrangements of the binding site. Antigen specificity can be explained through conserved interactions of DB3 with the steroid D-ring, whereas some of the crossreactivity is realized through different binding orientations of the steroid skeleton that place the A-ring into alternative pockets on the antibody surface. The restricted gene usage of the VGAM3.8 family in the generation of anti-progesterone monoclonal antibodies1,2 may be explained by the specific interaction Of V(H) hallmark residues with the steroid D-ring. This first detailed structure of steroid interactions with a protein could be applied to the understanding of general mechanisms of steroid recognition as well as in the design of specific binding sites for small hydrophobic ligands.
C1 SCRIPPS RES INST, DEPT MOLEC BIOL, LA JOLLA, CA 92037 USA.
   AFRC, BABRAHAM INST, DEPT IMMUNOL, STRUCT STUDIES LAB, CAMBRIDGE CB2 4AT, ENGLAND.
C3 Scripps Research Institute; UK Research & Innovation (UKRI); Biotechnology and Biological Sciences Research Council (BBSRC); Babraham Institute
NR 34
TC 159
Z9 165
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 859
EP 863
DI 10.1038/365859a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100057
PM 8413674
DA 2026-03-10
ER

PT J
AU ALLEN, JC
   SCHAFFER, WM
   ROSKO, D
AF ALLEN, JC
   SCHAFFER, WM
   ROSKO, D
TI CHAOS REDUCES SPECIES EXTINCTION BY AMPLIFYING LOCAL-POPULATION NOISE
SO NATURE
LA English
DT Article
ID space-limited subpopulations; ecological-systems; time-series; dynamics; models; rarity; growth
AB IN the mid-1970s, theoretical ecologists were responsible for stimulating interest in nonlinear dynamics and chaos1-3. Ironically, the importance of chaos in ecology itself remains controversial4-17. Proponents of ecological chaos point to its ubiquity in mathematical models and to various empirical findings15,16,18. Sceptics12,19,20 maintain that the models are unrealistic and that the experimental evidence is equally consistent with stochastic models. More generally, it has been argued9,11,21-23 that interdemic selection and/or enhanced rates of species extinction will eliminate populations and species that evolve into chaotic regions of parameter space. Fundamental to this opinion is the belief24,25 that violent oscillations and low minimum population densities are inevitable correlates of the chaotic state. In fact, rarity is not a necessary consequence of complex dynamical behaviour26,27. But even when chaos is associated with frequent rarity, its consequences to survival are necessarily deleterious only in the case of species composed of a single population. Of course, the majority of real world species (for example, most insects) consist of multiple populations weakly coupled by migration, and in this circumstance chaos can actually reduce the probability of extinction. Here we show that although low densities lead to more frequent extinction at the local level28, the decorrelating effect of chaotic oscillations reduces the degree of synchrony among populations and thus the likelihood that all are simultaneously extinguished.
C1 UNIV ARIZONA,DEPT ECOL & EVOLUTIONARY BIOL,TUCSON,AZ 85721.
C3 University of Arizona
RP ALLEN, JC (corresponding author), UNIV FLORIDA,DEPT ENTOMOL & NEMATOL,GAINESVILLE,FL 32611, USA.
NR 37
TC 293
Z9 316
U1 0
U2 33
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 229
EP 232
DI 10.1038/364229a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300054
PM 8321317
DA 2026-03-10
ER

PT J
AU FERNANDEZSARABIA, MJ
   BISCHOFF, JR
AF FERNANDEZSARABIA, MJ
   BISCHOFF, JR
TI BCL-2 ASSOCIATES WITH THE RAS-RELATED PROTEIN R-RAS P23
SO NATURE
LA English
DT Article
ID programmed cell-death; membrane protein; c-myc; gene; survival; product; expression; prevention; lines
AB APOPTOSIS is an important but poorly understood mechanism of cell regulation. Growth factor deprivation can trigger apoptosis in a variety of cells1-3, suggesting the existence of a signal transduction pathway responding to external signals and leading to apoptosis. Overexpression of the proto-oncogene bcl-2 can override these signals and block apoptosis4-14, indicating that the bcl-2 protein (Bcl-2) is an important component of the apoptotic response. The identification of Bcl-2-binding proteins might help explain how Bcl-2 acts to regulate apoptosis. Here we use the yeast two-hybrid system15 to show that the human ras-related protein R-ras p23 (refs 16-18) binds to Bcl-2. This association is also detected in immunoprecipitates from human cell extracts. The association requires full-length Bcl-2 but the C-terminal 60 amino acids of R-ras p23 are sufficient for the interaction. These results provide evidence of a putative component of a signal transduction pathway involved in the regulation of apoptosis.
RP FERNANDEZSARABIA, MJ (corresponding author), ONYX PHARMACEUT,3031 RES DR,BLDG A,RICHMOND,CA 94806, USA.
NR 24
TC 219
Z9 233
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 274
EP 275
DI 10.1038/366274a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500066
PM 8232588
DA 2026-03-10
ER

PT J
AU CHAPIN, FS
   MOILANEN, L
   KIELLAND, K
AF CHAPIN, FS
   MOILANEN, L
   KIELLAND, K
TI PREFERENTIAL USE OF ORGANIC NITROGEN FOR GROWTH BY A NONMYCORRHIZAL ARCTIC SEDGE
SO NATURE
LA English
DT Article
ID eriophorum-vaginatum; ectomycorrhizal plants; phosphate absorption; ammonium; nitrate; tundra; nutrition; peptides; temperature; phosphorus
AB PLANT growth in arctic tundra is strongly nitrogen-limited despite large pools of soil organic nitrogen1-4. Here we report that field-collected roots of Eriophorum vaginatum, an arctic sedge, rapidly absorb free amino acids, accounting for at least 60% of the nitrogen absorbed by this species in the field. In solution culture, Eriophorum accumulates more nitrogen and biomass when supplied with amino acids than when grown on inorganic nitrogen, whereas Hordeum vulgare (a cereal adapted to mineral soils) grows least when nitrogen is supplied as amino acids. To our knowledge, this is the first documentation of preferential absorption and use of organic nitrogen by a non-mycorrhizal vascular plant. The direct absorption of amino acids by Eriophorum short-circuits the bottle-neck in arctic nitrogen cycles imposd by temperature-limited mineralization.
C1 UNIV ALASKA,INST ARCTIC BIOL,FAIRBANKS,AK 99775.
C3 University of Alaska System; University of Alaska Fairbanks
RP CHAPIN, FS (corresponding author), UNIV CALIF BERKELEY,DEPT INTEGRAT BIOL,BERKELEY,CA 94720, USA.
NR 30
TC 568
Z9 696
U1 1
U2 194
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 150
EP 153
DI 10.1038/361150a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600058
DA 2026-03-10
ER

PT J
AU CHANG, SYP
   BOWMAN, BH
   WEISS, JB
   GARCIA, RE
   WHITE, TJ
AF CHANG, SYP
   BOWMAN, BH
   WEISS, JB
   GARCIA, RE
   WHITE, TJ
TI THE ORIGIN OF HIV-1 ISOLATE HTLV-IIIB
SO NATURE
LA English
DT Article
ID immunodeficiency-virus type-1; aids virus; nucleotide-sequence; retrovirus; evolution; risk; lav; dna
AB THE striking similarity between the first two human immunodeficiency virus type 1 (HIV-1) isolates Lai/LAV (formerly LAV, isolated at the Pasteur Institute1,2) and Lai/IIIB (formerly HTLV-IIIB, reported to be isolated from a pooled culture at the Laboratory of Tumor Cell Biology (LTCB) of the National Cancer Institute3,4) provoked considerable controversy in light of the high level of variability found among subsequent HIV-1 isolates5. In November 1990, the Office of Scientific Integrity at the National Institutes of Health commissioned our group to analyse archival samples established at the Pasteur Institute and LTCB between 1983 and 1985. Retrospective analyses6,7 have shown that contamination of a culture derived from patient BRU by one from patient LAI was responsible for the provenance of HIV-1 Lai/LAV; the contaminated culture (M2T-/B) was sent to LTCB in September 1983(6,7). Our goals were to determine which HIV-1 variants were present in the samples and the sequence diversity among HIV-1 isolates from the earliest stages of the AIDS epidemic. We examined archival specimens and report here the detection of six novel HIV-1 sequences in the cultures used to establish the pool: none is closely related to HIV-1 Lai/IIIB. A sample derived from patient LAI contained variants of both HIV-1 Lai/IIIB and HIV-1 Lai/LAV, and a sequence identical to a variant of HIV-1 Lai/IIIB was detected in the contaminated M2T-/B culture. We conclude that the pool, and probably another LTCB culture, MoV, were contaminated between October 1983 and early 1984 by variants of HIV-1 Lai from the M2T-/B culture. Therefore, the origin of the HIV-1 Lai/IIIB isolate also was patient LAI.
C1 ROCHE MOLEC SYST INC,1145 ATLANTIC AVE,ALAMEDA,CA 94501.
NR 27
TC 38
Z9 49
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 466
EP 469
DI 10.1038/363466a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800064
PM 8502298
DA 2026-03-10
ER

PT J
AU GU, Y
   TURCK, CW
   MORGAN, DO
AF GU, Y
   TURCK, CW
   MORGAN, DO
TI INHIBITION OF CDK2 ACTIVITY IN-VIVO BY AN ASSOCIATED 20K REGULATORY SUBUNIT
SO NATURE
LA English
DT Article
ID human cell-cycle; dna-replication; kinases; activation; proteins
AB THE major events of the cell division cycle are triggered by periodic changes in the activity of cyclin-dependent protein kinases (CDKs). In mammals, the members of the CDK family include CDK2 and CDC2, which are thought to be involved in the control of DNA replication and mitosis, respectively1-3. The protein kinase activity of these enzymes is controlled by a complex array of mechanisms4-6. Activation of the CDK catalytic subunit requires association with a positive regulatory subunit (cyclin) and phosphorylation (at Thr 160 in CDK2). This activated complex can be inhibited by additional phosphorylation at Thr 14 and Tyr 15. Here we report the identification of a new mechanism for the regulation of CDK2 activity. We find that CDK2/cyclin complexes in mouse fibroblasts associate tightly with a 20K protein (CAP20). Complexes containing CAP20 were isolated from cell lysates and found to have negligible kinase activity, indicating that CAP20 association in vivo may inhibit CDK2 activity. We purified CAP20 from 3T3 cells and found that low concentrations of the protein completely inhibit the kinase activity of CDK2 in vitro. Thus CAP20 represents a new negative regulatory subunit that inhibits the activity of CDK2/cyclin complexes in mammalian cells.
C1 UNIV CALIF SAN FRANCISCO,DEPT PHYSIOL,SAN FRANCISCO,CA 94143.
   UNIV CALIF SAN FRANCISCO,DEPT MED,SAN FRANCISCO,CA 94143.
   UNIV CALIF SAN FRANCISCO,HOWARD HUGHES MED INST,SAN FRANCISCO,CA 94143.
C3 University of California System; University of California San Francisco; University of California System; University of California San Francisco; Howard Hughes Medical Institute; University of California System; University of California San Francisco
NR 22
TC 787
Z9 856
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 707
EP 710
DI 10.1038/366707a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500076
PM 8259216
DA 2026-03-10
ER

PT J
AU SESSOLI, R
   GATTESCHI, D
   CANESCHI, A
   NOVAK, MA
AF SESSOLI, R
   GATTESCHI, D
   CANESCHI, A
   NOVAK, MA
TI MAGNETIC BISTABILITY IN A METAL-ION CLUSTER
SO NATURE
LA English
DT Article
ID quantum
AB MAGNETIC materials of mesoscopic dimensions (a few to many thousands of atoms) may exhibit novel and useful properties such as giant magnetostriction, magnetoresistivity and magnetocaloric effects1-4. Such materials also allow one to study the transition from molecular to bulk-like magnetic behaviour. One approach for preparing mesoscopic magnetic materials is to fragment bulk ferromagnets; a more controllable method is to take a 'bottom-up' approach, using chemistry to grow well defined clusters of metal ions5,6. Lis7 has described a twelve-ion manganese cluster in which eight of the Mn ions are in the +3 oxidation state (spin S = 2) and four are in the +4 state (S = 3/2). These ions are magnetically coupled to give an S = 10 ground state, giving rise to unusual magnetic relaxation properties8,9. Here we report that the magnetization of the Mn12 cluster is highly anisotropic and that the magnetization relaxation time becomes very long below a temperature of 4 K, giving rise to pronounced hysteresis. This behaviour is not, however, strictly analogous to that of a bulk ferromagnet, in which magnetization hysteresis results from the motion of domain walls. In principle, a bistable magnetic unit of this sort could act as a data storage device.
C1 UNIV FED RIO DE JANEIRO,INST FIS,BR-21944 RIO JANEIRO,BRAZIL.
   UNIV FLORENCE,DEPT CHEM,I-50144 FLORENCE,ITALY.
   CNRS,CTR RECH TRES BASSES TEMP,F-38042 GRENOBLE,FRANCE.
C3 Universidade Federal do Rio de Janeiro; University of Florence; Centre National de la Recherche Scientifique (CNRS)
NR 11
TC 3944
Z9 4140
U1 8
U2 720
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 141
EP 143
DI 10.1038/365141a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200042
DA 2026-03-10
ER

PT J
AU SHENG, M
   LIAO, YJ
   JAN, YN
   JAN, LY
AF SHENG, M
   LIAO, YJ
   JAN, YN
   JAN, LY
TI PRESYNAPTIC A-CURRENT BASED ON HETEROMULTIMERIC K+ CHANNELS DETECTED IN-VIVO
SO NATURE
LA English
DT Article
ID potassium channels; xenopus-oocytes; rat-brain; diversity; shaker; hippocampus; subunits; proteins; neurons; aplysia
AB A WIDE variety of voltage-gated K+ channels are involved in the regulation of neuronal excitability and synaptic transmission. Their heterogeneity arises in part from the large number of genes encoding different K+ channel subunits (reviewed in ref. 1).  In addition, heterologous expression studies indicate that assembly of distinct subunits into heteromultimeric channels may contribute further to K+ channel diversity2-6. A question has been whether heteromeric K+ channels actually form in vivo, and if so, whether specific combinations of subunits could account for major K+ currents identified in neurons. We present here biochemical evidence that Kv1.4 and Kv1.2, two K+ channel subunits of the Shaker subfamily, co-assemble in rat brain. The Kv1.4/Kv1.2 heteromultimer combines features of both parent subunits, resulting in an A-type K+ channel6.  Immunocytochemical evidence suggests that the heteromultimers are localized in axons and nerve terminals. We propose that Kv1.4/Kv1.2 heteromultimers may form the molecular basis of a presynaptic A-type K+ channel involved in the regulation of neurotransmitter release.
C1 UNIV CALIF SAN FRANCISCO,HOWARD HUGHES MED INST,DEPT BIOCHEM,SAN FRANCISCO,CA 94143.
C3 University of California System; University of California San Francisco; Howard Hughes Medical Institute
RP SHENG, M (corresponding author), UNIV CALIF SAN FRANCISCO,HOWARD HUGHES MED INST,DEPT PHYSIOL,SAN FRANCISCO,CA 94143, USA.
NR 18
TC 322
Z9 341
U1 1
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 72
EP 75
DI 10.1038/365072a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600057
PM 8361540
DA 2026-03-10
ER

PT J
AU NICOLELIS, MAL
   LIN, RCS
   WOODWARD, DJ
   CHAPIN, JK
AF NICOLELIS, MAL
   LIN, RCS
   WOODWARD, DJ
   CHAPIN, JK
TI INDUCTION OF IMMEDIATE SPATIOTEMPORAL CHANGES IN THALAMIC NETWORKS BY PERIPHERAL BLOCK OF ASCENDING CUTANEOUS INFORMATION
SO NATURE
LA English
DT Article
ID adult flying-fox; somatosensory cortex; digit denervation; receptive-fields; rat; deafferentation; monkeys; reorganization; plasticity; responses
AB PERIPHERAL sensory deprivation induces reorganization within the somatosensory cortex of adult animals1-6. Although most studies have focused on the somatosensory cortex1-6, changes at subcortical levels (for example the thalamus) could also play a fundamental role in sensory plasticity7-11. To investigate this, we made chronic simultaneous recordings of large numbers of single neurons across the ventral posterior medial thalamus (VPM) in adult rats. This allowed a continuous and quantitative evaluation of the receptive fields of the same sample of single VPM neurons per animal, before and after sensory deprivation. Local anaesthesia in the face induced an immediate and reversible reorganization of a large portion of the VPM map. This differentially affected the short latency (4-6 ms) responses (SLRs) and long latency (15-25 ms) responses (LLRs) of single VPM neurons. The SLRs and LLRs normally define spatiotemporally complex receptive fields in the VPM12. Here we report that 73% of single neurons whose original receptive fields included the anaesthetized zone showed immediate unmasking of SLRs in response to stimulation of adjacent cutaneous regions, and/or loss of SLRs with preservation or enhancement of LLRs in response to stimulation of regions just surrounding the anaesthetized zone. This thalamic reorganization demonstrates that peripheral sensory deprivation may induce immediate plastic changes at multiple levels of the somatosensory system. Further, its spatiotemporally complex character suggests a disruption of the normal dynamic equilibrium between multiple ascending and descending influences on the VPM.
C1 UNIV SAO PAULO,DEPT PATHOL,BR-01246 SAO PAULO,BRAZIL.
   WAKE FOREST UNIV,BOWMAN GRAY SCH MED,DEPT PHYSIOL & PHARMACOL,WINSTON SALEM,NC 27103.
C3 Universidade de Sao Paulo; Wake Forest University; Wake Forest Baptist Medical Center
RP NICOLELIS, MAL (corresponding author), HAHNEMANN UNIV,DEPT PHYSIOL & BIOPHYS,BROAD & VINE ST,PHILADELPHIA,PA 19102, USA.
NR 17
TC 188
Z9 217
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 533
EP 536
DI 10.1038/361533a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400059
PM 8429906
DA 2026-03-10
ER

PT J
AU LO, KY
   BACKER, DC
   KELLERMANN, KI
   REID, M
   ZHAO, JH
   GOSS, WM
   MORAN, JM
AF LO, KY
   BACKER, DC
   KELLERMANN, KI
   REID, M
   ZHAO, JH
   GOSS, WM
   MORAN, JM
TI HIGH-RESOLUTION VLBA IMAGING OF THE RADIO-SOURCE SGR-A-ASTERISK AT THE GALACTIC-CENTER
SO NATURE
LA English
DT Article
AB THE compact non-thermal radio source at the Galactic Centre, known as Sgr A*, may mark the location of a massive black hole1,2. Here we present images of Sgr A* with milliaresecond resolution obtained by using five telescopes of the partially completed Very Long Baseline Array (VLBA) in conjunction with a few additional telescopes. The image of Sgr A* at a wavelength of 3.6 cm confirms almost exactly the elliptical gaussian model that has been proposed on the basis of previous, more sparse data3,4. The source size at 1.35 cm wavelength is 2.4 +/- 0.2 mas, similar to previous results3,5. At both wavelengths, the radio source is smooth, without detectable fine structure. These observations, along with other recent results6, support the suggestion7 that the radio emission from Sgr A* is strongly scattered by electron-density fluctuations along the line of sight. On the assumption8 that the emission is due to a black hole accreting stellar winds from massive stars in the central 0.5 pc, the observations are consistent with a black-hole mass of less than or similar to 2 x 10(6) M..
C1 UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720.
   NATL RADIO ASTRON OBSERV,CHARLOTTESVILLE,VA 22903.
   HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138.
   NATL RADIO ASTRON OBSERV,SOCORRO,NM 87801.
C3 University of California System; University of California Berkeley; National Radio Astronomy Observatory (NRAO); Smithsonian Institution; Harvard University; Smithsonian Astrophysical Observatory; National Radio Astronomy Observatory (NRAO)
RP LO, KY (corresponding author), UNIV ILLINOIS,DEPT ASTRON,1002 W GREEN ST,URBANA,IL 61801, USA.
NR 28
TC 43
Z9 46
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 38
EP 40
DI 10.1038/362038a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600051
DA 2026-03-10
ER

PT J
AU NARAYAN, R
   POPHAM, R
AF NARAYAN, R
   POPHAM, R
TI HARD X-RAYS FROM ACCRETION DISK BOUNDARY-LAYERS
SO NATURE
LA English
DT Article
ID t-tauri stars; cataclysmic variables; emission; model; spectrum
AB ACCRETION disks1,2 are found in many astrophysical objects, ranging from newly formed stars and mass-transferring binary systems to quasars and other active galactic nuclei. An important feature of accretion disks is the boundary layer-the interface between the disk and the accreting objects-where up to half the accretion luminosity may be liberated. The lack of a satisfactory description of the flow and thermal structure of this layer has long been a handicap when modelling disk spectra. Here we report numerical solutions of a model of thin accretion disks around a central white dwarf which includes a self-consistent description of the boundary layer. We find two distinct kinds of solution depending on the mass accretion rate M. At high rates, we find optically thick boundary layers whose radial width and peak temperature decrease with decreasing M, but when the accretion rate falls below a critical value, the boundary layer becomes optically thin, and the width and temperature increase dramatically. Our results provide an explanation for the hard X-rays observed3 in cataclysmic variables, particularly at low M. It should be possible to extend our analysis to other accretion-disk systems.
RP NARAYAN, R (corresponding author), HARVARD SMITHSONIAN CTR ASTROPHYS,60 GARDEN ST,CAMBRIDGE,MA 02138, USA.
NR 20
TC 163
Z9 167
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 820
EP 822
DI 10.1038/362820a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300048
DA 2026-03-10
ER

PT J
AU LEIRS, H
   DEBRUYN, L
AF LEIRS, H
   DEBRUYN, L
TI NEW IDEAS FOR PERSONAL LIBRARY MAINTENANCE SOFTWARE
SO NATURE
LA English
DT Article
RP LEIRS, H (corresponding author), UNIV ANTWERP,DEPT BIOL,GROENENBORGERLAAN 171,B-2020 ANTWERP,BELGIUM.
NR 2
TC 1
Z9 1
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 183
EP 184
DI 10.1038/366183a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600065
PM 8232560
DA 2026-03-10
ER

PT J
AU GEHRELS, N
   CHEN, W
AF GEHRELS, N
   CHEN, W
TI THE GEMINGA SUPERNOVA AS A POSSIBLE CAUSE OF THE LOCAL INTERSTELLAR BUBBLE
SO NATURE
LA English
DT Article
ID gamma-ray source; optical counterpart; unique object; 1e 0630+178; error box; identification; explosions; field
AB THE Solar System resides at the edge of a cavity of hot (10(6) K), low-density (5 x 10(-3) cm-3), X-ray emitting gas embedded in the interstellar medium1-4. This void, sometimes called the Local Bubble, is thought to be less than 10(7) years old, but its origin is unknown. Here we propose that the void was caused by the supernova that produced the Geminga pulsar. The initial identification5 of Geminga as a pulsar, and the subsequent detection6-8 of pulsations in high-energy gamma-rays, give an age of 3 x 10(5) years and a pulsar distance in the range 40 to 400 pc (refs 6, 7). Using this information, and the recently discovered9,10 proper motion of a likely optical counterpart, we find that the supernova was well positioned to produce the local void, provided that the explosion occurred within about 60 pc of the Solar System. Larger distances are not excluded by our analysis, but they would put the supernova at a position for which there is no evidence for such an energy input.
RP GEHRELS, N (corresponding author), NASA, GODDARD SPACE FLIGHT CTR, HIGH ENERGY ASTROPHYS LAB, GREENBELT, MD 20771 USA.
NR 25
TC 70
Z9 73
U1 0
U2 0
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 706
EP 707
DI 10.1038/361706a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900048
DA 2026-03-10
ER

PT J
AU CAMPBELL, ID
   MCANDREWS, JH
AF CAMPBELL, ID
   MCANDREWS, JH
TI FOREST DISEQUILIBRIUM CAUSED BY RAPID LITTLE ICE-AGE COOLING
SO NATURE
LA English
DT Article
ID co2-induced climate change; pollen; vegetation; michigan; ontario
AB GLOBAL climatic change may alter species' ranges as well as restructuring ecosystems1-3. Models simulating forest growth predict that the area covered by different forest types may be affected2, which may in turn further affect climate3. In the mixed forests of southern Ontario, pollen analyses have demonstrated that after AD 1400, Fagus (beech), the formerly dominant warmth-loving species, was replaced first by oak (Quercus) and subsequently by pine (Pinus strobus). Although these changes had been attributed to aboriginal forest clearance4-6, they have also been seen in areas unaffected by aboriginal farming, and are now thought to reflect Little Ice Age cooling7. Although modelling suggests that some forests may take several centuries to reach equilibrium after a climatic change8,9, a real forest showing this behaviour has not previously been identified. Here we model the Little Ice Age by a 2-degrees-C decrease in mean annual temperature from AD 1200 to 1850, and show that the changes predicted by a forest simulator derived from FORET10 match those seen in southern Ontario. These forests thus appear to have remained in disequilibrium with the prevailing climate for more than 650 years.
C1 UNIV TORONTO,DEPT BOT,TORONTO M5S 1A1,ONTARIO,CANADA.
   ROYAL ONTARIO MUSEUM,DEPT BOT,TORONTO M5S 2C6,ONTARIO,CANADA.
C3 University of Toronto; Royal Ontario Museum
NR 23
TC 91
Z9 105
U1 1
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 336
EP 338
DI 10.1038/366336a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500046
DA 2026-03-10
ER

PT J
AU INGHAM, PW
AF INGHAM, PW
TI LOCALIZED HEDGEHOG ACTIVITY CONTROLS SPATIAL LIMITS OF WINGLESS TRANSCRIPTION IN THE DROSOPHILA EMBRYO
SO NATURE
LA English
DT Article
AB CELL patterning in the body segments of the Drosophila embryo requires activity of the segment polarity genes, a molecularly heterogeneous group defined by a generic mutant phenotype1. Two of these genes, wingless (wg) and hedgehog (hh), encode proteins that enter the secretory pathway2-4, implicating them as signals that instruct the fates of neighbouring cells5. Genetic analysis has identified wg transcription as one of the targets of hh activity6,7 and it has been suggested that the spatial control of wg expression depends on the limited range of the hh signal and the differential competence of responding cells8. I have tested this model by driving ubiquitous expression of the hh gene using the Hsp70 promoter. Here I report that, as predicted, this causes the ectopic activation of wg in only a subset of the cells of each parasegment. Using another target of hh activity as a probe, I demonstrate that the competence of cells to express wg is independent of their ability to receive the hh signal. Finally, I show that wg activation requires the function of the segment polarity gene fused, suggesting that the putative hh signal is transduced by the serine/threonine kinase that fused encodes.
RP INGHAM, PW (corresponding author), ICRF, DEV BIOL UNIT, DEPT ZOOL, MOLEC EMBRYOL LAB, S PARKS RD, OXFORD OX1 3PS, ENGLAND.
NR 28
TC 169
Z9 189
U1 0
U2 4
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 560
EP 562
DI 10.1038/366560a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800068
PM 8255293
DA 2026-03-10
ER

PT J
AU REID, RT
   LIVE, DH
   FAULKNER, DJ
   BUTLER, A
AF REID, RT
   LIVE, DH
   FAULKNER, DJ
   BUTLER, A
TI A SIDEROPHORE FROM A MARINE BACTERIUM WITH AN EXCEPTIONAL FERRIC ION AFFINITY CONSTANT
SO NATURE
LA English
DT Article
ID iron transport compounds; coordination chemistry; growth; phytoplankton; alteromonas; inhibition; analogs; waters
AB VIRTUALLY all microorganisms require iron for growth. The paucity of iron in surface ocean water (approximately 0.02-1.0 nM (refs 1, 2)) has spurred a lively debate concerning iron limitation of primary productivity3-6, yet little is known about the molecular mechanisms used by marine microorganisms to sequester iron. Terrestrial bacteria use a siderophore-mediated ferric uptake systems7. A siderophore is a low-molecular-mass compound with a high affinity for ferric ion which is secreted by microorganisms in response to low-iron environments; siderophore biosynthesis is regulated by iron levels, with repression by high iron. Although open-ocean marine microorganisms (such as phytoplankton8 and bacteria9) produce siderophores, the nature of these siderophores has not been investigated. We report here the first structure determination, to our knowledge, of the siderophores from an open-ocean bacterium, alterobactin A and B from Alteromonas luteoviolacea. A. luteoviolacea is found in oligotrophic10 and coastal11 waters. Alterobactin A has an exceptionally high affinity constant for ferric ion. We suggest that at least some marine microorganisms may have developed higher-affinity iron chelators as part of an efficient iron-uptake mechanism which is more effective than that of their terrestrial counterparts.
C1 UNIV CALIF SANTA BARBARA,DEPT CHEM,SANTA BARBARA,CA 93106.
   MEM SLOAN KETTERING CANC CTR,NEW YORK,NY 10021.
   UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093.
C3 University of California System; University of California Santa Barbara; Memorial Sloan Kettering Cancer Center; University of California System; University of California San Diego; Scripps Institution of Oceanography
NR 32
TC 196
Z9 230
U1 0
U2 56
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 455
EP 458
DI 10.1038/366455a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800061
PM 8247152
DA 2026-03-10
ER

PT J
AU MCADAM, WB
   OSBORNE, JL
   PARKINSON, ML
AF MCADAM, WB
   OSBORNE, JL
   PARKINSON, ML
TI A SUPERNOVA REMNANT ASSOCIATED WITH THE YOUNG GAMMA-RAY PULSAR PSR1706-44
SO NATURE
LA English
DT Article
ID dependence; g5.4-1.2
AB THE Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory satellite recently detected1 pulsed gamma-radiation from the radio pulsar PSR1706-44; this is only the fourth radio pulsar to be identified as a gamma-ray source. The other three (Vela, the Crab and PSR1509-58) are all associated with supernova remnants (SNRs), whereas very few-perhaps four-of the remaining 500 or so galactic radio pulsars have convincing associations with SNRs2. We have mapped the field around PSR1706-44 at 843 M Hz with a resolution of 44 arcsec using the Molonglo Observatory Synthesis Telescope, and have identified a shell-type SNR at a distance of about 3 kpc-consistent with the distance deduced for the pulsar. The pulsar is seen as a slightly variable point source, located in an enhanced knot on the arc of the SNR shell.
C1 UNIV DURHAM,DEPT PHYS,DURHAM DH1 3LE,ENGLAND.
C3 Durham University
RP MCADAM, WB (corresponding author), UNIV SYDNEY,SCH PHYS,SYDNEY,NSW 2006,AUSTRALIA.
NR 19
TC 51
Z9 53
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 516
EP 518
DI 10.1038/361516a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400052
DA 2026-03-10
ER

PT J
AU VERSCHUEREN, KHG
   SELJEE, F
   ROZEBOOM, HJ
   KALK, KH
   DIJKSTRA, BW
AF VERSCHUEREN, KHG
   SELJEE, F
   ROZEBOOM, HJ
   KALK, KH
   DIJKSTRA, BW
TI CRYSTALLOGRAPHIC ANALYSIS OF THE CATALYTIC MECHANISM OF HALOALKANE DEHALOGENASE
SO NATURE
LA English
DT Article
ID xanthobacter-autotrophicus gj10; alpha-helix dipole; x-ray-diffraction; halogenated alkanes; enzyme intermediate; serine proteinase; crystal; acetylcholinesterase; purification; degradation
AB Crystal structures of haloalkane dehalogenase were determined in the presence of the substrate 1,2-dichloroethane. At pH 5 and 4-degrees-C, substrate is bound in the active site without being converted; warming to room temperature causes the substrate's carbon-chlorine bond to be broken, producing a chloride ion with concomitant alkylation of the active-site residue Asp124. At pH 6 and room temperature the alkylated enzyme is hydrolysed by a water molecule activated by the His289-Asp260 pair in the active site. These results show that catalysis by the dehalogenase proceeds by a two-step mechanism involving an ester intermediate covalently bound at Asp124.
C1 UNIV GRONINGEN,BIOSON RES INST,NIJENBORGH 4,9747 AG GRONINGEN,NETHERLANDS.
   UNIV GRONINGEN,BIOPHYS CHEM LAB,9747 AG GRONINGEN,NETHERLANDS.
C3 University of Groningen; University of Groningen
NR 27
TC 428
Z9 453
U1 1
U2 53
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 693
EP 698
DI 10.1038/363693a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900047
PM 8515812
DA 2026-03-10
ER

PT J
AU PRENDERGAST, JR
   QUINN, RM
   LAWTON, JH
   EVERSHAM, BC
   GIBBONS, DW
AF PRENDERGAST, JR
   QUINN, RM
   LAWTON, JH
   EVERSHAM, BC
   GIBBONS, DW
TI RARE SPECIES, THE COINCIDENCE OF DIVERSITY HOTSPOTS AND CONSERVATION STRATEGIES
SO NATURE
LA English
DT Article
ID richness; biodiversity; choice; agony
AB SPECIES conservation in situ requires networks of protected areas selected for high conservation interest1-3. Throughout most of the world, however, there are neither the resources nor the time to carry out detailed inventories for most taxa2,4 before designating protected areas. Site selection (on grounds other than availability) would be easier and more effective if two things were true: (1) habitats that are species-rich for one taxon are also species-rich for others5; and (2) rare1 species occur in, and therefore benefit from the conservation of, species-rich habitats. Diversity (usually, species richness) and the presence of rare species are the most frequently cited criteria for site selection by conservationists6-8. Here, we use data on British plants and animals held by the Biological Records Centre (BRC)9 and the British Trust for Ornithology (BTO), mapped on a grid of 10 km x 10 km ('10 km squares') to examine the extent to which species-rich areas for different taxa coincide, and whether species-rich areas contain substantial numbers of rare species. The fine scale and high intensity of recording in Britain produces distributional datasets at least as good as and, in most cases, better than those available elsewhere. For Britain at least, we do not find strong support for either proposition. Species-rich areas ('hotspots'10) frequently do not coincide for different taxa, and many rare species do not occur in the most species-rich squares.
C1 NERC,INST TERR ECOL,CTR BIOL RECORDS,ABBOTS RIPTON PE17 2LS,CAMBS,ENGLAND.
   BRITISH TRUST ORNITHOL,THETFORD IP24 2PU,NORFOLK,ENGLAND.
C3 UK Research & Innovation (UKRI); Natural Environment Research Council (NERC); UK Centre for Ecology & Hydrology (UKCEH); British Trust for Ornithology
RP PRENDERGAST, JR (corresponding author), UNIV LONDON IMPERIAL COLL SCI & TECHNOL,NERC,CTR POPULAT BIOL,SILWOOD PK,ASCOT SL5 7PY,BERKS,ENGLAND.
NR 23
TC 897
Z9 1004
U1 0
U2 322
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 335
EP 337
DI 10.1038/365335a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600050
DA 2026-03-10
ER

PT J
AU FODOR, SPA
   RAVA, RP
   HUANG, XHC
   PEASE, AC
   HOLMES, CP
   ADAMS, CL
AF FODOR, SPA
   RAVA, RP
   HUANG, XHC
   PEASE, AC
   HOLMES, CP
   ADAMS, CL
TI MULTIPLEXED BIOCHEMICAL ASSAYS WITH BIOLOGICAL CHIPS
SO NATURE
LA English
DT Article
ID hybridization
C1 AFFYMAX,PALO ALTO,CA 94304.
RP FODOR, SPA (corresponding author), AFFYMETRIX,3380 CENT EXPRESSWAY,SANTA CLARA,CA 95051, USA.
NR 9
TC 609
Z9 1175
U1 0
U2 71
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 555
EP 556
DI 10.1038/364555a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700064
PM 7687751
DA 2026-03-10
ER

PT J
AU SHU, ZJ
   SWINDALE, NV
   CYNADER, MS
AF SHU, ZJ
   SWINDALE, NV
   CYNADER, MS
TI SPECTRAL MOTION PRODUCES AN AUDITORY AFTER-EFFECT
SO NATURE
LA English
DT Article
ID movement aftereffects contingent; frequency-modulated tones; direction; channels; pattern; color
AB DISTORTIONS of perception following prolonged exposure to an unvarying sensory stimulus have been observed since at least the third century BC1. The motion after-effect is a familiar experience2 in which, after a few minutes of viewing objects moving in a single direction, a stationary object appears to move in the opposite direction. Similar after-effects have been observed for many visual stimuli, including tilted lines, colours, stereoscopic depth, curvature, spatial frequency, contrast, rotation and motion in depth3-9. In contrast to the rich variety of visual after-effects reported since the 1960s, reports of analogous auditory adaptation effects only appeared in the 1970s10-12, but have continued since then13,14. Some effects of sound source spatial movement perception after adaptation to a spatially moving sound source have been reported15. Here we report an auditory perceptual after-effect analogous to the visual motion after-effect, which is caused by adaptation to auditory spectral (frequency) motion. After a few minutes of listening to a simple spectral pattern moving upwards or downwards in frequency space, the same pattern sounds as though it is drifting in the opposite direction when it is stationary. The effect shows binaural transfer, implying that it is generated at the level after binaural interaction. After-effects produced by the motion of spectral peaks are independent of those produced by spectral notches, suggesting separate processing channels for spectral peaks and notches.
C1 UNIV BRITISH COLUMBIA,DEPT ELECT ENGN,VANCOUVER V6T 1Z4,BC,CANADA.
C3 University of British Columbia
RP SHU, ZJ (corresponding author), UNIV BRITISH COLUMBIA,DEPT OPHTHALMOL,2550 WILLOW ST,VANCOUVER V5Z 3N9,BC,CANADA.
NR 22
TC 64
Z9 70
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 721
EP 723
DI 10.1038/364721a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700059
PM 8355786
DA 2026-03-10
ER

PT J
AU MOYA, M
   ROBERTS, D
   NOVICK, P
AF MOYA, M
   ROBERTS, D
   NOVICK, P
TI DSS4-1 IS A DOMINANT SUPPRESSOR OF SEC4-8 THAT ENCODES A NUCLEOTIDE EXCHANGE PROTEIN THAT AIDS SEC4P FUNCTION
SO NATURE
LA English
DT Article
ID plasma-membrane; ras proteins; yeast; dna; secretion; sequences; binding
AB THE protein Sec4p plays an essential role at the final stage of the yeast secretory pathway and belongs to the ras superfamily of GTP-binding proteins1, more specifically to a branch that includes Ypt1p in Saccharomyces cerevisiae and rab proteins in mammalian cells. GTP-binding proteins change conformation depending on whether GTP or GDP is bound2 and can thus act as a regulatory switch. The protein remains in its inactive, GDP-bound form until exchange of GTP for GDP allows it to stimulate a downstream effector. This interaction is curtailed by GTP hydrolysis. The rates of nucleotide exchange and GTP hydrolysis can be regulated by interaction with accessory proteins3. Although GDP dissociation stimulators (GDS) have been identified that act on members of the ras and rho branches of the superfamily, less is known regarding GDSs that act on members of the Sec4/Ypt1/Rab subgroup. A preliminary characterization of a Rab3A GDP dissociation stimulating activity has been presented4. We report here the use of suppressor analysis to clone a gene, dss4, encoding a 17K protein that aids Sec4p action in vivo by functioning as a GDP dissociation stimulator.
C1 YALE UNIV, SCH MED, DEPT CELL BIOL, 333 CEDAR ST, NEW HAVEN, CT 06510 USA.
C3 Yale University
NR 25
TC 105
Z9 108
U1 0
U2 6
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 460
EP 463
DI 10.1038/361460a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300064
PM 8429886
DA 2026-03-10
ER

PT J
AU ZARITSKY, D
   RIX, HW
   RIEKE, M
AF ZARITSKY, D
   RIX, HW
   RIEKE, M
TI INNER SPIRAL STRUCTURE OF THE GALAXY M51
SO NATURE
LA English
DT Article
AB MODELLING the structure and kinematics of spiral galaxies requires accurate maps of the mass-tracing stellar population. But this has hitherto been difficult because of dust obscuration and the presence of luminous young stars. To minimize the effects of dust and maximize sensitivity to the dominant stellar population, we have obtained K-band (2.2-mum) images of the nearby 'grand-design' spiral galaxy NGC5194 (M51). Our observations reveal remarkable dynamical structures not visible in conventional optical images. We find that the spiral arms extend significantly further towards the galaxy's centre than previously observed and can be traced continuously through almost three revolutions - roughly twice as far as with optical images. The coherence of the arms over this large radial range challenges current theories of spiral structure. We suggest that a combination of several mechanisms, such as the interaction of M51 with the neighbouring galaxy NGC5195, forcing by the central 'bar', or distortions from density waves, is required to generate the observed structure.
C1 INST ADV STUDY, PRINCETON, NJ 08540 USA.
   UNIV ARIZONA, STEWARD OBSERV, TUCSON, AZ 85721 USA.
C3 Institute for Advanced Study - USA; University of Arizona
RP ZARITSKY, D (corresponding author), CARNEGIE OBSERV, 813 SANTA BARBARA ST, PASADENA, CA 91101 USA.
NR 16
TC 44
Z9 44
U1 0
U2 2
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 313
EP 315
DI 10.1038/364313a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000048
DA 2026-03-10
ER

PT J
AU DIMARIO, JX
   FERNYAK, SE
   STOCKDALE, FE
AF DIMARIO, JX
   FERNYAK, SE
   STOCKDALE, FE
TI MYOBLASTS TRANSFERRED TO THE LIMBS OF EMBRYOS ARE COMMITTED TO SPECIFIC FIBER FATES
SO NATURE
LA English
DT Article
ID myogenic cell lineages; skeletal-muscle fibers; heavy-chain isoforms; thyroid-hormone; neural control; avian limb; myosin; expression
AB IN the limb bud of the 5-day-old avian embryo, when primary muscle fibre formation is beginning and before specific muscles appear, differences in the expression of fast and slow myosin heavy chain genes can be detected among primary fibres of the premuscle masses1,2. Myoblasts that form colonies of fibres of specific types can be isolated from these limb buds3. To assess the role of myoblast commitment in specifying fibre types during embryonic development, we cloned myoblasts of specific types from embryonic and adult muscles, transfected them with a reporter gene, and transferred them into developing limb buds. After transfer, cloned myoblasts formed fibres in the limb with the same patterns of myosin heavy chain gene expression as the fibres they formed in cell culture. These results demonstrate that initial skeletal muscle fibre type diversity during avian limb development can originate, in part, from the commitment of distinct myoblast types to the formation of specific fibre types.
C1 STANFORD UNIV,MED CTR,SCH MED,STANFORD,CA 94305.
C3 Stanford University
NR 18
TC 94
Z9 100
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 165
EP 167
DI 10.1038/362165a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800062
PM 8383807
DA 2026-03-10
ER

PT J
AU FUKUGITA, M
   HOGAN, CJ
   PEEBLES, PJE
AF FUKUGITA, M
   HOGAN, CJ
   PEEBLES, PJE
TI THE COSMIC DISTANCE SCALE AND THE HUBBLE CONSTANT
SO NATURE
LA English
DT Article
ID virgo cluster galaxy; cepheid distance; brightest stars; ia supernovae; time-delay; calibration; h0
AB Although astronomers can reliably measure the relative distances of distant galaxies, attempts to calibrate the absolute cosmic distance scale remain controversial. Nevertheless, the sources of possible error are now clearly defined and a convincing result seems to be within reach.
C1 INST ADV STUDY,PRINCETON,NJ 08540.
   UNIV WASHINGTON,SEATTLE,WA 98195.
   PRINCETON UNIV,PRINCETON,NJ 08544.
C3 Institute for Advanced Study - USA; University of Washington; University of Washington Seattle; Princeton University
RP FUKUGITA, M (corresponding author), KYOTO UNIV,YUKAWA INST,KYOTO 606,JAPAN.
NR 37
TC 59
Z9 61
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 309
EP 312
DI 10.1038/366309a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500038
DA 2026-03-10
ER

PT J
AU MICKLEM, G
   ROWLEY, A
   HARWOOD, J
   NASMYTH, K
   DIFFLEY, JFX
AF MICKLEM, G
   ROWLEY, A
   HARWOOD, J
   NASMYTH, K
   DIFFLEY, JFX
TI YEAST ORIGIN RECOGNITION COMPLEX IS INVOLVED IN DNA-REPLICATION AND TRANSCRIPTIONAL SILENCING
SO NATURE
LA English
DT Article
ID s-cerevisiae; ho gene; plasmid; phase
AB THE HMR E silencer represses transcription of silent mating-type genes in the budding yeast Saccharomyces cerevisiae and contains three redundant regulatory elements A, E and B (ref. 1). The A element contains the 11 base pair consensus sequence that is essential for the firing of DNA replication origins2. A multisubunit protein called the origin recognition complex (ORC) binds specifically to this consensus sequence within yeast origins in vitro3 and in vivo4. We isolated mutants in A element-mediated silencing and report here that one of the genes we identified, RRR1, encodes ORC2, the 72K subunit of ORC. RRR1/ORC2 is an essential gene, but the rrr1-316 allele, which is viable, is defective in the replication of nuclear DNA and the maintenance of the 2-mum episomal DNA. This is, to our knowledge, the first genetic evidence that ORC is involved in DNA replication and silencing.
C1 CRF, CLARE HALL LABS, S MIMMS EN6 3LD, HERTS, ENGLAND.
   RES INST MOLEC PATHOL, A-1030 VIENNA, AUSTRIA.
   MRC, MOLEC BIOL LAB, CAMBRIDGE CB2 2QH, ENGLAND.
C3 Vienna Biocenter (VBC); Research Institute of Molecular Pathology (IMP); MRC Laboratory Molecular Biology
NR 25
TC 213
Z9 245
U1 0
U2 5
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 87
EP 89
DI 10.1038/366087a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700062
PM 8232543
DA 2026-03-10
ER

PT J
AU HANSKI, I
   TURCHIN, P
   KORPIMAKI, E
   HENTTONEN, H
AF HANSKI, I
   TURCHIN, P
   KORPIMAKI, E
   HENTTONEN, H
TI POPULATION OSCILLATIONS OF BOREAL RODENTS - REGULATION BY MUSTELID PREDATORS LEADS TO CHAOS
SO NATURE
LA English
DT Article
ID microtine cycles; prey abundance; least weasels; nivalis; dynamics; hypothesis; numbers; size
AB THE four-year cycle of microtine rodents in boreal and arctic regions was first described in 1924 (ref. 1). Competing hypotheses on the mechanisms underlying the small mammal cycle have been extensively tested2-5, but so far the sustained rodent oscillations are unexplained. Here we use two mutually supportive approaches to investigate this question. First, building on studies of the interaction between rodents and their mustelid predators6-9, we construct a predator-prey model with seasonality. Second, we use a new technique of nonlinear analysis10,11 to examine empirical time-series data, and compare them with the model dynamics. The model parameterized with field data predicts dynamics that closely resemble the observed dynamics of boreal rodent populations. Both the predicted and observed dynamics are chaotic, albeit with a statistically significant periodic component. Our results suggest that the multiannual oscillations of rodent populations in Fennoscandia are due to delayed density dependence imposed by mustelid predators, and are chaotic.
C1 SO FOREST EXPT STN,PINEVILLE,LA 71360.
   UNIV TURKU,DEPT BIOL,ECOL ZOOL LAB,SF-20500 TURKU 50,FINLAND.
   FINNISH FOREST RES UNIT,DEPT FOREST ECOL,SF-01301 VANTAA,FINLAND.
C3 United States Department of Agriculture (USDA); United States Forest Service; University of Turku; Natural Resources Institute Finland (Luke)
RP HANSKI, I (corresponding author), UNIV HELSINKI,DEPT ZOOL,DIV ECOL,POB 17,P RAUTATIEKATU 13,SF-00014 HELSINKI,FINLAND.
NR 30
TC 385
Z9 412
U1 1
U2 86
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 232
EP 235
DI 10.1038/364232a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300055
PM 8321318
DA 2026-03-10
ER

PT J
AU JARAMILLO, F
   MARKIN, VS
   HUDSPETH, AJ
AF JARAMILLO, F
   MARKIN, VS
   HUDSPETH, AJ
TI AUDITORY ILLUSIONS AND THE SINGLE HAIR CELL
SO NATURE
LA English
DT Article
ID distortion products f2-f1; basilar-membrane; mechanoelectrical transduction; bullfrogs sacculus; combination tones; channels; adaptation; responses; cochlea; bundles
AB LIKE our other senses, the auditory system can produce illusions. Prominent among these are distortion products1-5: when listening to two tones, one of frequency f1 and the second of a higher frequency f2, an individual may hear not only these primary tones, but also a difference tone of frequency f2-f1, a sum tone of frequency f2+f1, and combination tones of frequencies such as 2f1-f2 and 2f2-f1. Discovered by Tartini early in the eighteenth century6,7, these illusory sounds are sufficiently conspicuous that they were employed to carry melodies in classical compositions. Distortion products originate within the cochlea, where they manifest themselves in the basilar membrane's vibration8. Here we demonstrate distortion products in individual hair cells of the bullfrog's sacculus, where they emerge from a nonlinearity inherent in the mechanoelectrical transduction process. In addition to offering an explanation for cochlear distortion products, our results suggest that the mechanical properties of hair bundles significantly influence the basilar membrane's motion.
RP JARAMILLO, F (corresponding author), UNIV TEXAS,SW MED CTR,CTR BASIC NEUROSCI RES,DALLAS,TX 75235, USA.
NR 38
TC 112
Z9 116
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 527
EP 529
DI 10.1038/364527a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700054
PM 8336792
DA 2026-03-10
ER

PT J
AU POLLEY, HW
   JOHNSON, HB
   MARINO, BD
   MAYEUX, HS
AF POLLEY, HW
   JOHNSON, HB
   MARINO, BD
   MAYEUX, HS
TI INCREASE IN C3 PLANT WATER-USE EFFICIENCY AND BIOMASS OVER GLACIAL TO PRESENT CO2 CONCENTRATIONS
SO NATURE
LA English
DT Article
ID carbon-dioxide concentration; atmospheric co2; isotopic composition; growth; vegetation; ambient; balance
AB ATMOSPHERIC CO2 concentration was 160 to 200 mumol mol-1 during the Last Glacial Maximum (LGM; about 18,000 years ago)1, rose to about 275 mumol mol-1 10,000 years ago2,3, and has increased to about 350 mumol mol-1 since 1800 (ref. 4). Here we present data indicating that this increase in CO2 has enhanced biospheric carbon fixation and altered species abundances by increasing the water-use efficiency of biomass production of C3 plants, the bulk of the Earth's vegetation. We grew oats (Avena sativa), wild mustard (Brassica kaber) and wheat (Triticum aestivum cv. Seri M82 and Yaqui 54), all C3 annuals, and selected C4 grasses along daytime gradients of Glacial to present atmospheric CO2 concentrations in a 38-m-long chamber. We calculated parameters related to leaf photosynthesis and water-use efficiency from stable carbon isotope ratios (C-13/C-12) of whole leaves. Leaf water-use efficiency and above-ground biomass/plant of C3 species increased linearly and nearly proportionally with increasing CO2 concentrations. Direct effects of increasing CO2 on plants must be considered when modelling the global carbon cycle and effects of climate change on vegetation.
C1 HARVARD UNIV,DEPT EARTH & PLANETARY SCI,CAMBRIDGE,MA 02138.
   HARVARD UNIV,DIV APPL SCI,CAMBRIDGE,MA 02138.
C3 Harvard University; Harvard University
RP POLLEY, HW (corresponding author), DEPT AGR,AGR RES SERV,808 E BLACKLAND RD,TEMPLE,TX 76502, USA.
NR 30
TC 301
Z9 349
U1 0
U2 114
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 61
EP 64
DI 
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800047
DA 2026-03-10
ER

PT J
AU HAMELIN, M
   ZHOU, YW
   SU, MW
   SCOTT, IM
   CULOTTI, JG
AF HAMELIN, M
   ZHOU, YW
   SU, MW
   SCOTT, IM
   CULOTTI, JG
TI EXPRESSION OF THE UNC-5 GUIDANCE RECEPTOR IN THE TOUCH NEURONS OF C-ELEGANS STEERS THEIR AXONS DORSALLY
SO NATURE
LA English
DT Article
ID embryonic cell lineages; caenorhabditis-elegans; guides cell; migrations; genetics; immunoglobulin; nematode; protein
AB GROWTH cones in developing nervous systems encounter a sequence of extracellular cues during migration1,2. In theory, a growth cone can navigate by selectively expressing or activating surface receptor(s) that recognize extracellular cues appropriate to each migratory phase. Using the simple Caenorhabditis elegans nervous system, we attempted to demonstrate that path selection by migrating growth cones can be predictably altered by ectopic expression of a single receptor. The unc-5 gene of C. elegans encodes a unique receptor of the immunoglobulin superfamily (UNC-5), required cell-autonomously to guide growth cone and mesodermal cell migrations in a dorsal direction on the epidermis3,4. We report here that the UNC-5 receptor induces dorsally oriented axon trajectories when ectopically expressed in the touch receptor neurons which normally extend pioneer axons longitudinally or ventrally on the epidermis5. These errant trajectories depend on unc-6, which encodes a putative epidermal path cue6, just as normal dorsally oriented axon trajectories do (such as those of certain motor neurons4), suggesting that UNC-5 acts to reorient the touch cell growth cones by using its normal guidance mechanisms. These results support previous evidence that UNC-5 and UNC-6 play instructive roles in guiding growth cone migrations on the epidermis in C elegans4, and indicate that pioneering growth cones, which normally migrate in different directions may use equivalent intracellular signalling mechanisms for guidance.
C1 MT SINAI HOSP,SAMUEL LUNENFELD RES INST,TORONTO M5G 1X5,ONTARIO,CANADA.
   UNIV TORONTO,DEPT MOLEC & MED GENET,TORONTO M5S 1A8,ONTARIO,CANADA.
   MERCK RES LABS,RAHWAY,NJ 07065.
C3 University of Toronto; Sinai Health System Toronto; Lunenfeld Tanenbaum Research Institute; University of Toronto; Merck & Company
NR 16
TC 207
Z9 254
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 327
EP 330
DI 10.1038/364327a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000054
PM 8332188
DA 2026-03-10
ER

PT J
AU LANZER, M
   DEBRUIN, D
   RAVETCH, JV
AF LANZER, M
   DEBRUIN, D
   RAVETCH, JV
TI TRANSCRIPTIONAL DIFFERENCES IN POLYMORPHIC AND CONSERVED DOMAINS OF A COMPLETE CLONED PLASMODIUM-FALCIPARUM CHROMOSOME
SO NATURE
LA English
DT Article
ID parasite plasmodium-falciparum; histidine-rich protein; involve deletions; gene; sequence; rearrangement; expression; cross
AB CLASSICAL genetic studies on the human malaria parasite Plasmodium falciparum have been hampered by a complex life cycle which alternates between vertebrate and invertebrate hosts. Consequently, only a few genetic crosses have been performed so far1-4. In addition, molecular genetics has provided only limited access to the genes of this pathogen, a consequence of an unusually high A + T content5,6. To overcome these limitations we have constructed an ordered telomere-to-telomere contig map of P. falciparum chromosome 2 by isolating overlapping yeast artificial chromosome clones. This approach was used to examine the strain-dependent polymorphisms commonly observed for P. falciparum chromosomes7,8. Our analysis reveals that polymorphisms of chromosome 2 are restricted to regions at either end, representing 20% of the chromosome. Transcription mapping of the entire chromosome suggests a compartmentalization of chromosome 2 into a transcribed central domain and silent polymorphic ends.
RP LANZER, M (corresponding author), SLOAN KETTERING INST CANC RES,DEWITT WALLACE RES LAB,DIV MOLEC BIOL,1275 YORK AVE,NEW YORK,NY 10021, USA.
NR 24
TC 61
Z9 63
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 654
EP 657
DI 10.1038/361654a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600069
PM 8437626
DA 2026-03-10
ER

PT J
AU FULARA, J
   LESSEN, D
   FREIVOGEL, P
   MAIER, JP
AF FULARA, J
   LESSEN, D
   FREIVOGEL, P
   MAIER, JP
TI LABORATORY EVIDENCE FOR HIGHLY UNSATURATED-HYDROCARBONS AS CARRIERS OF SOME OF THE DIFFUSE INTERSTELLAR BANDS
SO NATURE
LA English
DT Article
ID absorption; features; carbon; c10h8+
AB THERE are many absorption lines in the visible and near-infrared spectra of stars located on the far side of diffuse interstellar clouds. The origin of these 'diffuse interstellar bands' (DIBs) has remained an unanswered question since their discovery almost 70 years ago1,2. There are now over 100 known bands1,3-6 and it is clear from the range of line widths, depths and shapes that the lines are unlikely to come from a single 'carrier'. Many of the proposed carriers, such as gas-phase carbon chains7, fullerenes8 and dust grains9, fail in having ultraviolet absorption lines where none has yet been observed in the stellar spectra. Polycyclic aromatic species such as C16H10+ (ref. 10) and C10H8 (ref. 11) were recently claimed to be good candidates for carriers of some of the DIBs. Here we present laboratory evidence that highly unsaturated hydrocarbons with carbon numbers 6-12 may be the carriers of some of the DIBs in the range 480-1,000 nm. We deposit mass-selected molecules in a neon matrix at 5 K and measure their near-infrared, visible and ultraviolet spectra. Not only do these species have visible and near-infrared lines corresponding to fifteen DIBs, but they also show no absorption lines in the ultraviolet, consistent with astronomical observations.
RP FULARA, J (corresponding author), UNIV BASEL,INST PHYS CHEM,KLINGELBERGSTR 80,CH-4056 BASEL,SWITZERLAND.
NR 26
TC 127
Z9 133
U1 1
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 439
EP 441
DI 10.1038/366439a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800055
DA 2026-03-10
ER

PT J
AU MACLEOD, DIA
   HE, S
AF MACLEOD, DIA
   HE, S
TI VISIBLE FLICKER FROM INVISIBLE PATTERNS
SO NATURE
LA English
DT Article
ID monkey macaca-fascicularis; sensitivity; adaptation; vision; cones
AB USING a laser interferometer we can create grating patterns of high optical contrast (interference fringes) directly on the retina1-3. With coarse fringe patterns, the alternating light and dark bars of the pattern can be seen, but the bars of the finest fringes are not subjectively resolved. We report here that when we rapidly modulate the contrast of a fine fringe pattern (keeping overall luminance constant), observers experience flicker, even if the fringes are too finely spaced to be perceived as a grating. For this flicker to be seen, the pattern needs to be resolvable by the photoreceptors themselves, but not necessarily by later stages of visual processing. It can be explained if, in man, signals associated with individual cone receptors do not depend linearly on light intensity, but instead are scaled by a fast sensitivity-regulating or light-adaptation mechanism. Contrast-modulation flicker is not demonstrable in rod vision; rod vision therefore lacks such a local adaptation process.
RP MACLEOD, DIA (corresponding author), UNIV CALIF SAN DIEGO,DEPT PSYCHOL,LA JOLLA,CA 92093, USA.
NR 14
TC 40
Z9 40
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 256
EP 258
DI 10.1038/361256a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400058
PM 8423852
DA 2026-03-10
ER

PT J
AU THIEL, DJ
   LIVINS, P
   STERN, EA
   LEWIS, A
AF THIEL, DJ
   LIVINS, P
   STERN, EA
   LEWIS, A
TI MICROSECOND-RESOLVED XAFS OF THE TRIPLET EXCITED-STATE OF PT2(P2O5H2)4(4-)
SO NATURE
LA English
DT Article
ID binuclear platinum(ii); electronic spectroscopy; diphosphite complexes; spectra; raman; absorption
AB LITTLE is known about the excited-state structures of most inorganic compounds. Time-resolved resonance Raman and time-resolved infrared spectroscopies can provide only indirect structural information for short-lived excited species in solution at room temperature. Time-resolved X-ray diffraction' has the potential to give more direct information, but no excited-state structures have yet been reported; picosecond gas-phase electron diffraction has been proposed recently2, but not yet demonstrated. Here we report a technique that combines the X-ray absorption fine-structure (XAFS) method3 With rapid-flow laser spectroscopy4 to measure structural changes in a solution-phase excited-state transition-metal complex with microsecond resolution. We find that the triplet excited state of Pt2(P2O5H2)44-, with a lifetime of about 4 mus, undergoes a contraction in the Pt-Pt distance of 0.52 +/- 0.13 angstrom relative to the ground state. We anticipate that time-resolved XAFS will have broad applications in chemistry and biology.
C1 UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195.
   HEBREW UNIV JERUSALEM,DIV APPL PHYS,JERUSALEM,ISRAEL.
C3 University of Washington; University of Washington Seattle; Hebrew University of Jerusalem
RP THIEL, DJ (corresponding author), CORNELL UNIV,DEPT APPL PHYS,ITHACA,NY 14853, USA.
NR 20
TC 72
Z9 74
U1 0
U2 25
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 40
EP 43
DI 10.1038/362040a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600052
PM 8383295
DA 2026-03-10
ER

PT J
AU REES, M
AF REES, M
TI TRADE-OFFS AMONG DISPERSAL STRATEGIES IN BRITISH PLANTS
SO NATURE
LA English
DT Article
ID seedling emergence; environments; periodicity; survival; seeds
AB TRADE-OFFS are of fundamental importance in population biology. They prevent the evolution of a darwinian demon (a species that breeds fast, fives long and is both a good competitor and disperser) and result in the wide range of life histories we observe in nature1. Trade-offs are also thought to be important in ecology, driving successional change and maintaining species diversity2,3. But the demonstration of trade-offs is difficult4,5. Evolutionary theory predicts trade-offs between seed dormancy and (1) seed weight6 and (2) seed Spatial dispersal6,7. Here we present simulation results predicting a third trade-off between seed dormancy and adult longevity. The existence of these trade-offs is tested, to our knowledge for the first time, using modern comparative methods8,9 and data from long-term experiments10-12. The analyses are consistent with the existence of all three trade-offs in nature.
C1 UNIV LONDON IMPERIAL COLL SCI & TECHNOL, NERC, CTR POPULAT BIOL, ASCOT SL5 7PY, BERKS, ENGLAND.
C3 Imperial College London; UK Research & Innovation (UKRI); Natural Environment Research Council (NERC)
RP REES, M (corresponding author), UNIV LONDON IMPERIAL COLL SCI & TECHNOL, DEPT BIOL, SILWOOD PK, ASCOT SL5 7PY, BERKS, ENGLAND.
NR 30
TC 157
Z9 196
U1 1
U2 75
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 150
EP 152
DI 10.1038/366150a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600055
DA 2026-03-10
ER

PT J
AU HENKEL, T
   MACHLEIDT, T
   ALKALAY, I
   KRONKE, M
   BEN-NERIAH, Y
   BAEUERLE, PA
AF HENKEL, T
   MACHLEIDT, T
   ALKALAY, I
   KRONKE, M
   BEN-NERIAH, Y
   BAEUERLE, PA
TI RAPID PROTEOLYSIS OF I-KAPPA-B-ALPHA IS NECESSARY FOR ACTIVATION OF TRANSCRIPTION FACTOR NF-KAPPA-B
SO NATURE
LA English
DT Article
ID protein-kinase-c; tumor-necrosis-factor; dna-binding; inhibitor; phosphorylation; interleukin-1; precursor; enhancer; invitro; cells
AB INDUCIBLE gene expression in eukaryotes is mainly controlled by the activity of transcriptional activator proteins, such as NF-kappaB (refs 1-3), a factor activated upon treatment of cells with phorbol esters, lipopolysaccharide4, interleukin-1 and tumour necrosis factor-alpha5. Activation of NF-kappaB involves release of the inhibitory subunit IkappaB from a cytoplasmic complex with the DNA-binding subunits Rel-A (formerly p65) and p50 (refs 6, 7). Cell-free experiments have suggested that protein kinase C and other kinases transfer phosphoryl groups onto IkappaB causing release of IkappaB and subsequent activation of NF-kappaB8-10. Here we report that IkappaB-alpha (formerly MAD-3)11 is degraded in cells after stimulation with phorbol ester, interleukin-1, lipopolysaccharide and tumour necrosis factor-alpha, an event coincident with the appearance of active NF-kappaB. Treatment of cells with various protease inhibitors or an antioxidant completely prevented the inducible decay of IkappaB-alpha as well as the activation of NF-kappaB. Our findings suggest that the activation of NF-kappaB relies on an inducible degradation of IkappaB-alpha through a cytoplasmic, chymotrypsin-like protease. In intact cells, phosphorylation of IkappaB-alpha is apparently not sufficient for activation of NF-kappaB.
C1 GENE CTR, MOLEC BIOL LAB, KLOPFERSPITZ 18A, W-8033 MARTINSRIED, GERMANY.
   HEBREW UNIV JERUSALEM, HADASSAH MED SCH, LAUTENBERG CTR GEN & TUMOR IMMUNOL, IL-91010 JERUSALEM, ISRAEL.
   TECH UNIV MUNICH, INST MIKROBIOL & HYG, W-8000 MUNICH 2, GERMANY.
C3 Hebrew University of Jerusalem; Technical University of Munich
NR 29
TC 1133
Z9 1199
U1 0
U2 24
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 182
EP 185
DI 10.1038/365182a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200054
PM 8371761
DA 2026-03-10
ER

PT J
AU ARCHIBALD, DD
   MANN, S
AF ARCHIBALD, DD
   MANN, S
TI TEMPLATE MINERALIZATION OF SELF-ASSEMBLED ANISOTROPIC LIPID MICROSTRUCTURES
SO NATURE
LA English
DT Article
ID acid monolayers; biomineralization; bilayers; protein; tubules
AB THE high-fidelity replication and functional specificity of biomaterials and biopolymers is inspiring a renewal in the development of biomimetic strategies for materials synthesis1,2. Approaches involving the templating or nucleation of inorganic materials by compressed monolayers of amphiphiles3-5, the use of supramolecular lipid or protein cages in the preparation of nanoscale inorganic structures6-8 and the mineralization of bacterial fibres9 indicate the potential of controlled crystallization at inorganic-organic interfaces. Here we report the controlled formation of tubular inorganic-organic composites by using self-assembled lipid tubules as templates for the crystallization of inorganic oxides. We use microstructures formed by a sugar-based lipid galactocerebroside, doped with small amounts of an anionic sulphated derivative, to induce nucleation of magnetic and non-magnetic iron oxides. By varying the reaction conditions, we can create either tube-like or lamellar disk-like composites. Our results suggest that the variety of microstructures formed by chemically modified sugar-based lipids may provide a route to the production of mineral-containing fibres and other ceramic-organic composites.
C1 UNIV BATH,SCH CHEM,BATH BA2 7AY,AVON,ENGLAND.
C3 University of Bath
NR 21
TC 318
Z9 345
U1 1
U2 93
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 430
EP 433
DI 10.1038/364430a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000050
DA 2026-03-10
ER

PT J
AU SCHILLING, A
   CANTONI, M
   GUO, JD
   OTT, HR
AF SCHILLING, A
   CANTONI, M
   GUO, JD
   OTT, HR
TI SUPERCONDUCTIVITY ABOVE 130-K IN THE HG-BA-CA-CU-O SYSTEM
SO NATURE
LA English
DT Article
AB THE recent discovery1 of superconductivity below a transition temperature (T(c)) of 94 K in HgBa2CuO4+delta has extended the repertoire of high-T(c) superconductors containing copper oxide planes embedded in suitably structured (layered) materials. Previous experience with similar compounds containing bismuth and thallium instead of mercury suggested that even higher transition temperatures might be achieved in mercury-based compounds with more than one CuO2 layer per unit cell. Here we provide support for this conjecture, with the discovery of superconductivity above 130 K in a material containing HgBa2Ca2Cu3O1+x (with three CuO2 layers per unit cell), HgBa2CaCu2O6+x (with two CuO2 layers) and an ordered superstructure comprising a defined sequence of the unit cells of these phases. Both magnetic and resistivity measurements confirm a maximum transition temperature of approximately 133 K, distinctly higher than the previous established record value of 125-127 K observed in Tl2Ba2Ca2Cu3O10 (refs 2, 3).
RP SCHILLING, A (corresponding author), SWISS FED INST TECHNOL,FESTKORPERPHYS LAB,CH-8093 ZURICH,SWITZERLAND.
NR 6
TC 1432
Z9 1656
U1 9
U2 1324
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 56
EP 58
DI 10.1038/363056a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200054
DA 2026-03-10
ER

PT J
AU IMAI, Y
   LASKY, LA
   ROSEN, SD
AF IMAI, Y
   LASKY, LA
   ROSEN, SD
TI SULFATION REQUIREMENT FOR GLYCAM-1, AN ENDOTHELIAL LIGAND FOR L-SELECTIN
SO NATURE
LA English
DT Article
ID lymphocyte homing receptor; leukocyte adhesion molecule-1; carbohydrate ligand; cell-adhesion; sialyl-lex; recognition; elam-1; recirculation; cdna
AB L-SELECTIN participates in the initial attachment of leukocytes to the vascular endothelium1-3. On lymphocytes, it mediates binding to high endothelial venules of lymph nodes. As a selectin 4-6 it functions as a calcium-dependent lectin7,8 recognizing carbohydrate-bearing ligands on endothelial cells9-11. Two lymph node ligands for L-selectin have been identified as sulphated glycoproteins of M(r) approximately 50K and approximately 90K, called Sgp50 and Sgp90 (ref. 10). The recently cloned Sgp50 (ref 12), now designated GlyCAM-1, is a high endothelial venule-associated, mucin-like glycoprotein containing predominantly O-linked carbohydrate chains. Sialylation of GlyCAM-1 is necessary for its ligand activity9,10,13 and a role for fucosylation is suspected13. We have used chlorate as a metabolic inhibitor of sulphation, and report here that GlyCAM-1 has an additional requirement for sulphate.
C1 UNIV CALIF SAN FRANCISCO,DEPT ANAT,SAN FRANCISCO,CA 94143.
   UNIV CALIF SAN FRANCISCO,PROGRAM IMMUNOL,SAN FRANCISCO,CA 94143.
   GENENTECH INC,DEPT IMMUNOBIOL,S SAN FRANCISCO,CA.
C3 University of California System; University of California San Francisco; University of California System; University of California San Francisco; Roche Holding; Roche Holding USA; Genentech
NR 29
TC 340
Z9 366
U1 1
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 555
EP 557
DI 
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400067
PM 7679207
DA 2026-03-10
ER

PT J
AU LIVACCARI, RF
   GEISSMAN, JW
   REYNOLDS, SJ
AF LIVACCARI, RF
   GEISSMAN, JW
   REYNOLDS, SJ
TI PALEOMAGNETIC EVIDENCE FOR LARGE-MAGNITUDE, LOW-ANGLE NORMAL FAULTING IN A METAMORPHIC CORE COMPLEX
SO NATURE
LA English
DT Article
ID south mountains; central nevada; origin; extension; rotation; transition; evolution; regions; arizona; uplift
AB CONTROVERSY exists over whether large-magnitude extensional deformation can occur along low-angle, master detachment (normal) faults1-16. Large amounts of Cenozoic extension occurred in the Basin and Range province of the western United States, and master detachment faults related to this extension are currently exposed as subhorizontal structures along crustal arches known as metamorphic core complexes (MCCs)10,11,17. One set of models suggests that MCCs represent crustal-scale blocks bounded by originally high-angle normal faults which have tilted to subhorizontal attitudes1-6. More dynamic models propose isostatically induced flexural tilting of an initial subhorizontal fault, to an active high-angle fault, to final abandonment as a subhorizontal structure7-9; these models require MCC detachment faults and their footwalls to have been tilted by 30-60-degrees. Alternatively, MCC detachment faults may have originated as subhorizontal or low-angle structures10-16. Here we test these models with palaeomagnetic data from undeformed portions of the South Mountains, a typical Cenozoic MCC in the southern Basin and Range province18-24. Comparison with time-averaged expected directions of the geomagnetic field25-27 yields no evidence for tilting of the footwall. We conclude that the South Mountains master detachment fault was active as a low-angle extensional structure, with a dip of approximately 10-degrees.
C1 ARIZONA STATE UNIV,DEPT GEOL,TEMPE,AZ 85287.
C3 Arizona State University; Arizona State University-Tempe
RP LIVACCARI, RF (corresponding author), UNIV NEW MEXICO,DEPT EARTH & PLANETARY SCI,ALBUQUERQUE,NM 87131, USA.
NR 32
TC 29
Z9 31
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 56
EP 59
DI 10.1038/361056a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800045
DA 2026-03-10
ER

PT J
AU MARCHIONNI, MA
   GOODEARL, ADJ
   CHEN, MS
   BERMINGHAMMCDONOGH, O
   KIRK, C
   HENDRICKS, M
   DANEHY, F
   MISUMI, D
   SUDHALTER, J
   KOBAYASHI, K
   WROBLEWSKI, D
   LYNCH, C
   BALDASSARE, M
   HILES, I
   DAVIS, JB
   HSUAN, JJ
   TOTTY, NF
   OTSU, M
   MCBURNEY, RN
   WATERFIELD, MD
   STROOBANT, P
   GWYNNE, D
AF MARCHIONNI, MA
   GOODEARL, ADJ
   CHEN, MS
   BERMINGHAMMCDONOGH, O
   KIRK, C
   HENDRICKS, M
   DANEHY, F
   MISUMI, D
   SUDHALTER, J
   KOBAYASHI, K
   WROBLEWSKI, D
   LYNCH, C
   BALDASSARE, M
   HILES, I
   DAVIS, JB
   HSUAN, JJ
   TOTTY, NF
   OTSU, M
   MCBURNEY, RN
   WATERFIELD, MD
   STROOBANT, P
   GWYNNE, D
TI GLIAL GROWTH-FACTORS ARE ALTERNATIVELY SPLICED ERBB2 LIGANDS EXPRESSED IN THE NERVOUS-SYSTEM
SO NATURE
LA English
DT Article
ID schwann-cell proliferation; peripheral-nerve; neu oncogene; gene; ethylnitrosourea; identification; regeneration; degeneration; mitogens; culture
AB Glial growth factors, proteins that are mitogenic for Schwann cells, and several ligands for the p185erbB2 receptor, are products of the same gene. Alternative splicing of the messenger RNA generates an array of putative membrane-attached, intracellular and secreted signalling proteins, at least some of which are expressed in the developing spinal cord and brain. These factors are probably important in the development and regeneration of the nervous system.
C1 LUDWIG INST CANC RES,LONDON W1P 8BT,ENGLAND.
   COLUMBIA UNIV,HOWARD HUGHES MED INST,NEW YORK,NY 10032.
C3 Ludwig Institute for Cancer Research; Columbia University; Howard Hughes Medical Institute
RP MARCHIONNI, MA (corresponding author), CAMBRIDGE NEUROSCI INC,1 KENDALL SQ,BLDG 700,CAMBRIDGE,MA 02139, USA.
NR 51
TC 728
Z9 834
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 312
EP 318
DI 10.1038/362312a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600050
PM 8096067
DA 2026-03-10
ER

PT J
AU PIJNAPPEL, WWM
   HENDRIKS, HFJ
   FOLKERS, GE
   VANDENBRINK, CE
   DEKKER, EJ
   EDELENBOSCH, C
   VANDERSAAG, PT
   DURSTON, AJ
AF PIJNAPPEL, WWM
   HENDRIKS, HFJ
   FOLKERS, GE
   VANDENBRINK, CE
   DEKKER, EJ
   EDELENBOSCH, C
   VANDERSAAG, PT
   DURSTON, AJ
TI THE RETINOID LIGAND 4-OXO-RETINOIC ACID IS A HIGHLY-ACTIVE MODULATOR OF POSITIONAL SPECIFICATION
SO NATURE
LA English
DT Article
ID central-nervous-system; xenopus-laevis; 13-cis-4-oxoretinoic acid; 13-cis-retinoic acid; carcinoma-cells; identification; metabolism; receptor; expression; activation
AB RETINOIDS (vitamin A and its metabolites) are suspected of regulating diverse aspects of growth, differentiation, and patterning during embryogenesis1, but many questions remain about the identities and functions of the endogenous active retinoids involved. The pleiotropic effects of retinoids may be explained by the existence of complex signal transduction pathways involving diverse nuclear receptors of the retinoic acid receptor (RAR) and retinoid X receptor (RXR) families, and at least two types of cellular retinoic acid binding proteins (CRABP-I and -II)2. The different RARs, RXRs, and CRABPs have different expression patterns during vertebrate embryogenesis2,3, suggesting that they each have particular functions. Another level at which fine tuning of retinoid action could occur is the metabolism of vitamin A to active metabolites, which may include all-trans-retinoic acid4-7, all-trans-3,4-didehydroretinoic acid8, 9-cis-retinoic acid9,10, and 14-hydroxy-4,14-retroretinol11. Formation of the metabolite all-trans-4-oxo-retinoic acid from retinoic acid was considered to be an inactivation pathway during growth and differentiation12,14. We report here that, in contrast, 4-oxo-retinoic acid is a highly active metabolite which can modulate positional specification in early embryos. We also show that this retinoid binds avidly to and activates RARbeta, and that it is available in early embryos. The different activities of 4-oxo-retinoic acid and retinoic acid in modulating positional specification on the one hand, and growth and differentiation on the other, interest us in the possibility that specific retinoid ligands regulate different physiological processes in vivo.
C1 TNO, INST AGEING & VASC RES, 2300 AK LEIDEN, NETHERLANDS.
C3 Netherlands Organization Applied Science Research
RP PIJNAPPEL, WWM (corresponding author), NETHERLANDS INST DEV BIOL, HUBRECHT LAB, UPPSALALAAN 8, 3584 CT UTRECHT, NETHERLANDS.
NR 31
TC 250
Z9 273
U1 0
U2 14
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 340
EP 344
DI 10.1038/366340a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500048
PM 8247127
DA 2026-03-10
ER

PT J
AU MACK, DH
   VARTIKAR, J
   PIPAS, JM
   LAIMINS, LA
AF MACK, DH
   VARTIKAR, J
   PIPAS, JM
   LAIMINS, LA
TI SPECIFIC REPRESSION OF TATA-MEDIATED BUT NOT INITIATOR-MEDIATED TRANSCRIPTION BY WILD-TYPE-P53
SO NATURE
LA English
DT Article
ID mammalian-cells; p53; promoter; activation; antigen; protein
AB THE p53 protein is apparently central to the development of human cancers because both alleles are often found to be mutated in different tumour types1. In addition, wild-type p53 can inhibit transformation by viral and cellular oncogenes in vitro, so p53 has been classified as a tumour suppressor2. Investigations of the normal function of p53 have indicated that at least one of its functions could involve the activation of gene expression through the binding of specific DNA-regulatory sequences3,4. Also, overexpression of p53 can mediate growth arrest5 and repress transcription from a variety of promoters6,7. We demonstrate here both in vivo and in vitro that expression of wild-type p53 specifically represses the activity of promoters whose initiation is dependent on the presence of a TATA box. Promoters whose accurate transcription is directed by a pyrimidine-rich initiator element, however, are immune to the effects of p53. Furthermore, we observe that repression is mediated by an interaction of p53 with basal transcription factor(s). Thus, p53 appears to repress the activity of certain promoters through direct communication with TATA box-dependent basal transcription machinery.
C1 UNIV CHICAGO,DEPT MOLEC GENET & CELL BIOL,5841 S MARYLAND AVE,CHICAGO,IL 60637.
   UNIV CHICAGO,HOWARD HUGHES MED INST,CHICAGO,IL 60637.
   UNIV PITTSBURGH,DEPT BIOL SCI,PITTSBURGH,PA 15260.
C3 University of Chicago; University of Chicago; Howard Hughes Medical Institute; Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh
NR 26
TC 345
Z9 362
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 281
EP 283
DI 10.1038/363281a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600058
PM 8387645
DA 2026-03-10
ER

PT J
AU MOSSER, J
   DOUAR, AM
   SARDE, CO
   KIOSCHIS, P
   FEIL, R
   MOSER, H
   POUSTKA, AM
   MANDEL, JL
   AUBOURG, P
AF MOSSER, J
   DOUAR, AM
   SARDE, CO
   KIOSCHIS, P
   FEIL, R
   MOSER, H
   POUSTKA, AM
   MANDEL, JL
   AUBOURG, P
TI PUTATIVE X-LINKED ADRENOLEUKODYSTROPHY GENE SHARES UNEXPECTED HOMOLOGY WITH ABC TRANSPORTERS
SO NATURE
LA English
DT Article
ID class-ii region; childhood adrenoleukodystrophy; color-vision; dna probe; protein; linkage; green; acid; adrenomyeloneuropathy; identification
AB ADRENOLEUKODYSTROPHY (ALD) is an X-linked disease affecting 1/20,000 males either as cerebral ALD in childhood or as adrenomyeloneuropathy (AMN) in adults1. Childhood ALD is the more severe form, with onset of neurological symptoms between 5-12 years of age. Central nervous system demyelination progresses rapidly and death occurs within a few years. AMN is a milder form of the disease with onset at 15-30 years of age and a more progressive course. Adrenal insufficiency (Addison's disease) may remain the only clinical manifestation of ALD. The principal biochemical abnormality of ALD is the accumulation of very-long-chain fatty acids (VLCFA) because of impaired beta-oxidation in peroxisomes1-2. The normal oxidation of VLCFA-CoA in patients' fibroblasts3-5 suggested that the gene coding for the VLCFA-CoA synthetase could be a candidate gene for ALD. Here we use positional cloning to identify a gene partially deleted in 6 of 85 independent patients with ALD. In familial cases, the deletions segregated with the disease. An identical deletion was detected in two brothers presenting with different clinical ALD phenotypes. Candidate exons were identified by computer analysis of genomic sequences6 and used to isolate complementary DNAs by exon connection7 and screening of cDNA libraries. The deduced protein sequence shows significant sequence identity to a peroxisomal membrane protein of M(r) 70K that is involved in peroxisome biogenesis and belongs to the 'ATP-binding cassette' superfamily of transporters.
C1 UNIV PARIS 05,HOP ST VINCENT DE PAUL,FAC COCHIN,INSERM,U342,82 AVE DENFERT ROCHEREAU,F-75014 PARIS,FRANCE.
   FAC MED STRASBOURG,INST CHIM BIOL,CNRS,GENET MOLEC EUCARYOTES LAB,INSERM,U184,F-67085 STRASBOURG,FRANCE.
   GERMAN CANC RES CTR,INST VIRUSFORSCH,W-6900 HEIDELBERG 1,GERMANY.
   KENNEDY KRIEGER INST,BALTIMORE,MD 21205.
C3 Universite Paris Cite; Assistance Publique Hopitaux Paris (APHP); Hopital Universitaire Cochin - APHP; Institut National de la Sante et de la Recherche Medicale (Inserm); Centre National de la Recherche Scientifique (CNRS); Universites de Strasbourg Etablissements Associes; Universite de Strasbourg; Institut National de la Sante et de la Recherche Medicale (Inserm); Helmholtz Association; German Cancer Research Center (DKFZ); Kennedy Krieger Institute
NR 39
TC 1021
Z9 1095
U1 1
U2 62
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 726
EP 730
DI 10.1038/361726a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900057
PM 8441467
DA 2026-03-10
ER

PT J
AU DUNAWAY, M
   OSTRANDER, EA
AF DUNAWAY, M
   OSTRANDER, EA
TI LOCAL DOMAINS OF SUPERCOILING ACTIVATE A EUKARYOTIC PROMOTER INVIVO
SO NATURE
LA English
DT Article
ID transcription factor; xenopus-laevis; dna; gene; enhancer; polymerase; template; oocytes; protein
AB EXPERIMENTS Correlating template topology with transcriptional activity suggest that DNA topology plays a role in eukaryotic gene expression1-4. Linear templates transfected into cultured cells produce far fewer transcripts than do circular transcription templates3, and no transcripts can be detected from linear templates injected into Xenopus oocytes1,2. Further, when transcriptionally active circular templates in Xenopus oocytes are linearized by injection of a restriction enzyme, transcription dramatically decreases. Here we show that transcription by phage T7 RNA polymerase from a divergent promoter can partially replace the requirement for circular Xenopus ribosomal RNA transcription templates in Xenopus oocytes. Supercoiled domains can apparently be generated on short pieces of DNA having no known sequences that result in association with the nuclear architecture, suggesting that localized, transient domains of supercoiling fulfil the minimum topological needs for Xenopus rRNA transcription in vivo.
C1 LAWRENCE BERKELEY LAB,CTR HUMAN GENOME,DEPT CELLULAR & MOLEC BIOL,BERKELEY,CA 94720.
C3 United States Department of Energy (DOE); Lawrence Berkeley National Laboratory
RP DUNAWAY, M (corresponding author), UNIV CALIF BERKELEY,DEPT MOLEC & CELL BIOL,DIV BIOCHEM & MOLEC BIOL,BERKELEY,CA 94720, USA.
NR 18
TC 92
Z9 102
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 746
EP 748
DI 10.1038/361746a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900063
PM 8441472
DA 2026-03-10
ER

PT J
AU MARTIN, JL
   BARDWELL, JCA
   KURIYAN, J
AF MARTIN, JL
   BARDWELL, JCA
   KURIYAN, J
TI CRYSTAL-STRUCTURE OF THE DSBA PROTEIN REQUIRED FOR DISULFIDE BOND FORMATION IN-VIVO
SO NATURE
LA English
DT Article
ID escherichia-coli glutaredoxin; macromolecular structures; 3-dimensional structure; disulfide-isomerase; thioredoxin; resolution; identification; crystallography; refinement; sequence
AB PROTEINS that contain disulphide bonds are often slow to fold in vitro because the oxidation and correct pairing of the cysteine residues is rate limiting1,2. The folding of such proteins is greatly accelerated in Escherichia coli by DsbA3,4, but the mechanism of this rate enhancement is not well understood. Here we report the crystal structure of oxidized DsbA and show that it resembles closely the ubiquitous redox protein thioredoxin5, despite very low sequence similarity. An important difference, however, is the presence of another domain which forms a cap over the thioredoxin-like active site of DsbA. The redox-active disulphide bond, which is responsible for the oxidation of substrates, is thus at a domain interface and is surrounded by grooves and exposed hydrophobic side chains. These features suggest that DsbA might act by binding to partially folded polypeptide chains before oxidation of cysteine residues.
C1 ROCKEFELLER UNIV,NEW YORK,NY 10021.
   HOWARD HUGHES MED INST,NEW YORK,NY 10021.
   HARVARD UNIV,SCH MED,DEPT MICROBIOL & MOLEC GENET,BOSTON,MA 02115.
C3 Rockefeller University; Howard Hughes Medical Institute; Harvard University; Harvard Medical School
NR 35
TC 368
Z9 412
U1 1
U2 25
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 464
EP 468
DI 10.1038/365464a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300064
PM 8413591
DA 2026-03-10
ER

PT J
AU WILSON, DS
AF WILSON, DS
TI CONFIRMATION OF THE ASTRONOMICAL CALIBRATION OF THE MAGNETIC POLARITY TIMESCALE FROM SEA-FLOOR SPREADING RATES
SO NATURE
LA English
DT Article
ID brunhes-matuyama; time scale; boundary; reversal; bp
AB THE dating of the history of reversals of the Earth's magnetic field since the Jurassic period has been based primarily on radiometric dating of a small number of reversals, with most ages of individual reversals interpolated or extrapolated on the basis of the widths of marine magnetic anomalies. Recently, however, Pliocene and Pleistocene reversals have been dated by an entirely independent method, which relies on correlating climate proxies (such as oxygen isotope ratios) in sediments with calculated variations of the Earth's orbit and inclination1-4. The dates obtained from this astronomical calibration are approximately 3-8% older than radiometrically calibrated ages published between 1979 and 1989 (see, for example, refs 5 and 6), although recent dating by the 40Ar/39Ar method tends to confirm the astronomical calibration7-10, at least for the past 3.3 Myr. Here I use sea-floor spreading rates determined from high-precision plate-rotation solutions for five plate pairs to test the astronomically calibrated timescale over the past 5.32 Myr. The results suggest that the errors in the astronomical calibration are no greater than 0.02 Myr, and also show that spreading rate can remain constant for several million years, even for fast-moving plates.
C1 UNIV CALIF SANTA BARBARA, INST MARINE SCI, SANTA BARBARA, CA 93106 USA.
C3 University of California System; University of California Santa Barbara
RP WILSON, DS (corresponding author), UNIV CALIF SANTA BARBARA, DEPT GEOL SCI, SANTA BARBARA, CA 93106 USA.
NR 16
TC 55
Z9 57
U1 0
U2 4
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 788
EP 790
DI 10.1038/364788a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100051
DA 2026-03-10
ER

PT J
AU JENKINS, FA
   WALSH, DM
AF JENKINS, FA
   WALSH, DM
TI AN EARLY JURASSIC CAECILIAN WITH LIMBS
SO NATURE
LA English
DT Article
ID dermophis-mexicanus amphibia; tooth crown morphology; gymnophiona; evolution
AB CAECILIANS are elongate, limbless, mostly fossorial amphibians. Less well known than frogs and salamanders, they are represented today by about 34 genera and 162 species1. Until recently, the fossil record of caecilians consisted of only two vertebrae, one from the Palaeocene of Brazil2, the other from the Late Cretaceous of Bolivia3. We report here the discovery of an extensive series of Early Jurassic caecilians which extends the fossil record of the group and reveals numerous features, including limbs, that are unknown among modern species. Although the new taxon possesses a tentacular fossa for a chemosensory organ and specializations of the jaw apparatus that are uniquely caecilian, other derived features are shared with salamanders and, among extinct Palaeozoic forms, with microsaurs. The configuration of the skull roof, which differs from the fenestrated condition typical of frogs, salamanders and putatively primitive living caecilians, is evidence of substantial evolutionary divergence between caecilians and other modern amphibian groups.
C1 HARVARD UNIV,MUSEUM COMPARAT ZOOL,CAMBRIDGE,MA 02138.
   UNIV LONDON,KINGS COLL,DEPT PHILOSOPHY,LONDON WC2 2LS,ENGLAND.
C3 Harvard University; University of London; King's College London
RP JENKINS, FA (corresponding author), HARVARD UNIV,DEPT ORGANISM & EVOLUT BIOL,CAMBRIDGE,MA 02138, USA.
NR 18
TC 100
Z9 109
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 246
EP 250
DI 
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100052
DA 2026-03-10
ER

PT J
AU NGUYEN, M
   STRUBEL, NA
   BISCHOFF, J
AF NGUYEN, M
   STRUBEL, NA
   BISCHOFF, J
TI A ROLE FOR SIALYL LEWIS-X/A GLYCOCONJUGATES IN CAPILLARY MORPHOGENESIS
SO NATURE
LA English
DT Article
ID leukocyte adhesion molecule-1; carbohydrate ligand; cell-adhesion; activation antigen; e-selectin; elam-1; endothelium; recognition; induction; invitro
AB To identify cell adhesion molecules required for angiogenesis, we used an in vitro model in which bovine capillary endothelial cells can be induced to form capillary-like tubes. Monoclonal antibodies directed against the carbohydrate epitopes sialyl Lewis-X and sialyl Lewis-A inhibited capillary formation. We postulated that a member of the selectin family of adhesion molecules may be involved in capillary formation because these proteins bind to sialyl Lewis-X/A-containing ligands. We isolated a 2.8-kilobase complementary DNA from a bovine capillary endothelial cell cDNA library which encodes a polypeptide with 71% identity to human E-selectin. We report here that antibody directed against the bovine E-selectin inhibited capillary formation, suggesting that in addition to its role in leukocyte adhesion to endothelium, a form of E-selectin is involved in capillary morphogenesis.
C1 CHILDRENS HOSP MED CTR,SURG RES LAB,300 LONGWOOD AVE,BOSTON,MA 02115.
   BRIGHAM & WOMENS HOSP,DEPT SURG,BOSTON,MA 02115.
   HARVARD UNIV,SCH MED,DEPT CELLULAR & MOLEC PHYSIOL,BOSTON,MA 02115.
   HARVARD UNIV,SCH MED,DEPT SURG,BOSTON,MA 02115.
C3 Harvard University; Harvard University Medical Affiliates; Boston Children's Hospital; Harvard University; Harvard University Medical Affiliates; Brigham & Women's Hospital; Harvard University; Harvard Medical School; Harvard University; Harvard Medical School
NR 27
TC 208
Z9 219
U1 1
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 267
EP 269
DI 10.1038/365267a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100059
PM 7690465
DA 2026-03-10
ER

PT J
AU CARLBERG, C
   BENDIK, I
   WYSS, A
   MEIER, E
   STURZENBECKER, LJ
   GRIPPO, JF
   HUNZIKER, W
AF CARLBERG, C
   BENDIK, I
   WYSS, A
   MEIER, E
   STURZENBECKER, LJ
   GRIPPO, JF
   HUNZIKER, W
TI 2 NUCLEAR SIGNALING PATHWAYS FOR VITAMIN-D
SO NATURE
LA English
DT Article
ID human osteocalcin gene; d receptor; thyroid-hormone; retinoic acid; elements; binding; 1,25-dihydroxyvitamin-d3; superfamily; expression; cells
AB THE dihydroxylated form of vitamin D3(1,25-dihydroxy-D3) mediates a biological response by binding to intracellular receptors1-4 which belong to the steroid receptor superfamily5. These receptors act as ligand-dependent transcription factors that bind to specific DNA sequences (reviewed in refs 6-9). We have identified two classes of vitamin D response elements that are activated either by the vitamin D receptor (VDR) alone or by heterodimers of VDR and the retinoid-X receptor-alpha (RXR-alpha)10. The motif GGGTGA arranged as a direct repeat with a spacing of six nucleotides or as a palindrome without spacing, or as an inverted palindrome with a 12-nucleotide spacing, confers vitamin D inducibility mediated by VDR alone. A second class of response elements, composed of directly repeated pairs of motifs (GGTCCA, AGGTCA, or GGGTGA) spaced by three nucleotides, is synergistically activated by RXR and VDR, but only in the presence of both ligands. Thus, the RXR ligand and the nature of the response element determine whether a nuclear receptor is co-regulated by RXR.
C1 F HOFFMANN LA ROCHE & CO LTD, DEPT PHARMA RES NEW TECHNOL, CH-4002 BASEL, SWITZERLAND.
   HOFFMANN LA ROCHE INC, DEPT TOXICOL & PATHOL, NUTLEY, NJ 07110 USA.
C3 Roche Holding; Roche Holding; Roche Holding USA
NR 32
TC 546
Z9 577
U1 0
U2 19
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 657
EP 660
DI 10.1038/361657a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600070
PM 8382345
DA 2026-03-10
ER

PT J
AU PORTER, RK
   BRAND, MD
AF PORTER, RK
   BRAND, MD
TI BODY-MASS DEPENDENCE OF H+ LEAK IN MITOCHONDRIA AND ITS RELEVANCE TO METABOLIC-RATE
SO NATURE
LA English
DT Article
ID relative proton stoichiometry; inner membrane; liver-mitochondria; permeability; force; conductance; pumps
AB THE standard metabolic rate of an animal is the rate of heat production under conditions that minimize known extra requirements for energy1,2. In tissues and cells from aerobic organisms, energy expenditure can conveniently be measured as oxygen consumption3,4. Measurements made using isolated rat hepatocytes have shown that a significant contribution to resting oxygen consumption (and hence heat production) is made by a futile cycle of proton pumping and proton leak across the mitochondrial inner membrane5. Two important factors affecting standard metabolic rate, thyroid status and phylogeny, also affect the proton permeability5-10. A third major factor affecting standard metabolic rate is body mass11,12. Here we show that proton leak decreases with increasing body mass in mammals. We suggest that differences in proton leak may partly explain the differences in standard metabolic rate between mammals of different mass.
RP PORTER, RK (corresponding author), UNIV CAMBRIDGE,DEPT BIOCHEM,TENNIS COURT RD,CAMBRIDGE CB2 1QW,ENGLAND.
NR 26
TC 233
Z9 248
U1 0
U2 20
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 628
EP 630
DI 10.1038/362628a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800046
PM 8385274
DA 2026-03-10
ER

PT J
AU CHOW, YK
   HIRSCH, MS
   MERRILL, DP
   BECHTEL, LJ
   ERON, JJ
   KAPLAN, JC
   DAQUILA, RT
AF CHOW, YK
   HIRSCH, MS
   MERRILL, DP
   BECHTEL, LJ
   ERON, JJ
   KAPLAN, JC
   DAQUILA, RT
TI USE OF EVOLUTIONARY LIMITATIONS OF HIV-1 MULTIDRUG RESISTANCE TO OPTIMIZE THERAPY
SO NATURE
LA English
DT Article
ID reverse-transcriptase inhibitors; virus; replication; zidovudine; derivatives; sensitivity; invitro; mutants; azt
AB WILD-TYPE reverse transcriptase has evolved for the survival of human immunodeficiency virus type 1 (HIV-1) by natural selection1. In contrast, therapy relying on inhibitors of reverse transcriptase by nucleosides like zidovudine (AZT) or dideoxyinosine (ddI), and by non-nucleosides like pyridinones or nevirapine2-6, may exert different selection pressures on this enzyme. Therefore the acquisition of resistance to reverse transcriptase inhibitors by selection of mutations in the pol gene7-15 may require compromises in enzyme function that affect viral replication. As single mutations are unlikely to confer broad resistance when combinations of reverse transcriptase inhibitors are used, multiple mutations may occur that result in further compromises. Certain drug combinations may prevent the co-existence of adequate reverse transcription function and multi-drug resistance (MDR). Unlike bacterial or eukaryotic drug resistance, retroviral drug resistance is conferred only by mutations in its own genome16 and is limited by genome size. Combining drugs directed against the same essential viral protein may thus prevent HIV-1 MDR, whereas the conventional approach of targeting different HIV-1 proteins for combination therapy may not, because genomes with resistance mutations in different HIV-1 genes might recombine to develop MDR17. Here we show that several mutations in the HIV-1 reverse transcriptase gene that confer resistance to inhibitors of this enzyme can attenuate viral replication. We tested whether combinations of mutations giving rise to single-agent resistance might further compromise or even abolish viral replication, and if multidrug-resistant viruses could be constructed. Certain combinations of mutations conferring resistance to AZT, ddI and pyridinone are incompatible with viral replication. These results indicate that evolutionary limitations exist to restrict development of MDR. Furthermore, a therapeutic strategy exploiting these limitations by using selected multidrug regimens directed against the same target may prevent development of MDR. This approach, which we call convergent combination therapy, eliminated HIV-1 replication and virus breakthrough in vitro, and may be applicable to other viral targets. Moreover, elimination of reverse transcription by convergent combination therapy may also limit MDR.
C1 HARVARD UNIV,SCH MED,BOSTON,MA 02115.
C3 Harvard University; Harvard Medical School
RP CHOW, YK (corresponding author), MASSACHUSETTS GEN HOSP,INFECT DIS UNIT,GRAY 5,BOSTON,MA 02114, USA.
NR 30
TC 155
Z9 172
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 650
EP 654
DI 10.1038/361650a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600068
PM 7679778
DA 2026-03-10
ER

PT J
AU LARSON, SB
   KOSZELAK, S
   DAY, J
   GREENWOOD, A
   DODDS, JA
   MCPHERSON, A
AF LARSON, SB
   KOSZELAK, S
   DAY, J
   GREENWOOD, A
   DODDS, JA
   MCPHERSON, A
TI DOUBLE-HELICAL RNA IN SATELLITE TOBACCO MOSAIC-VIRUS
SO NATURE
LA English
DT Article
ID phenylalanine transfer-rna; human rhinovirus-14; icosahedral virus; necrosis virus; resolution; refinement; sequence; crystals; strategy; programs
AB SATELLITE tobacco mosaic virus (STMV) is the spherical satellite to an obligatory rod-shaped helper tobacco mosaic virus (TMV), which is required for replication1,2. STMV has 60 protein subunits of M(r) 17,500 on a T = 1 icosahedral capsid3 containing a single-stranded RNA genome of 1,059 bases4-6. STMV appears similar to another virus, STNV7,8, but is approximately 20 per cent smaller. It shows no amino-acid homology or immunological cross-reactivity with either STNV or its host TMV4,9. Here we report the X-ray crystal structure of STMV, which shows that the coat protein of STMV contains a 'Swiss roll' beta-barrel. An amino-terminal strand extends more than 60angstrom and is primarily responsible for quaternary interactions. Each capsid dimer is associated with a segment of genomic RNA double helix comprising seven base pairs. The dyad of each protein dimer is coincident with that of the central base pair of the associated RNA segment whose helix axis is directed along an icosahedral edge. Protein-nucleic acid interactions are extensive. The RNA helices, which have additional stacked bases at their 3' termini, differ significantly from canonical nucleic acid helical forms.
C1 UNIV CALIF RIVERSIDE, DEPT PLANT PATHOL, RIVERSIDE, CA 92521 USA.
C3 University of California System; University of California Riverside
RP LARSON, SB (corresponding author), UNIV CALIF RIVERSIDE, DEPT BIOCHEM, RIVERSIDE, CA 92521 USA.
NR 38
TC 99
Z9 105
U1 0
U2 12
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 179
EP 182
DI 10.1038/361179a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600068
PM 8421525
DA 2026-03-10
ER

PT J
AU KARNI, A
   SAGI, D
AF KARNI, A
   SAGI, D
TI THE TIME-COURSE OF LEARNING A VISUAL SKILL
SO NATURE
LA English
DT Article
ID texture-discrimination; cortex; orientation
AB SEVERAL examples of experience-dependent perceptual improvement (perceptual learning) suggest that plasticity in specific neuronal loci could underlie the learning process1-6. For a basic visual discrimination task (using an optimal stimulus for 'automatic' pre-attentive texture segregation7-10), discrete retinal input-dependent changes within a very early stage in the stream of visual processing were indicated as the locus of a large and consistent learning effect5. When do these changes occur? Here we report that except for a fast, rapidly saturating improvement early in the first practice session, performance was very stable within sessions. Indeed, observers showed little or no improvement until up to 8 hours after their last training session (latent phase). But large improvements occurred thereafter. Finally, there was almost no forgetting; what was gained was retained for at least 2-3 years. We conjecture that some types of perceptual experience trigger permanent neural changes in early processing stages of the adult visual system. These may take many hours to become functional.
C1 WEIZMANN INST SCI,DEPT NEUROBIOL,IL-76100 REHOVOT,ISRAEL.
C3 Weizmann Institute of Science
NR 22
TC 672
Z9 795
U1 1
U2 61
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 250
EP 252
DI 10.1038/365250a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100053
PM 8371779
DA 2026-03-10
ER

PT J
AU DAMUTH, J
AF DAMUTH, J
TI COPES RULE, THE ISLAND RULE AND THE SCALING OF MAMMALIAN POPULATION-DENSITY
SO NATURE
LA English
DT Article
ID body size; abundance; birds; evolution; animals
AB COPE'S rule-the generalization that animal taxa tend to evolve toward larger body size suggests that there are widespread net selective advantages to being large1-4. Size-abundance relationships within bird4-7 and desert rodent4 guilds show that larger species usually do control more energy locally, and thus maintain larger populations than expected for their body size, implying that larger individuals are relatively better at obtaining and using local resources. But we report here results that show that this is not generally the case among mammal species. Within dietary groups containing only small species, larger species usually do better, but within those that contain the largest mammals, small species tend to control more energy. This suggests that in mammals there is an optimum body size for energy acquisition at about 1 kg. Thus, net adaptive advantages of large individuals for resource control cannot be used as a general explanation for evolutionary size increase in mammals, although other proposed explanations for Cope's rule are unaffected8-10. Instead, these results suggest a partial explanation for another widespread ecotypic pattern, the 'island rule': that on islands, small mammal species evolve to larger size and large species to smaller size11-13. If on an island a species' usual competitors and predators are absent, it should often tend to evolve toward the optimum body size, and the adaptive advantages of doing so would be greatest for populations starting at body-size extremes.
RP DAMUTH, J (corresponding author), UNIV CALIF SANTA BARBARA,DEPT BIOL SCI,SANTA BARBARA,CA 93106, USA.
NR 34
TC 201
Z9 218
U1 0
U2 68
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 748
EP 750
DI 10.1038/365748a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200061
PM 8413651
DA 2026-03-10
ER

PT J
AU DE SILVA, AP
   GUNARATNE, HQN
   MCCOY, CP
AF DE SILVA, AP
   GUNARATNE, HQN
   MCCOY, CP
TI A MOLECULAR PHOTOIONIC AND GATE BASED ON FLUORESCENT SIGNALING
SO NATURE
LA English
DT Article
ID photoinduced electron-transfer; supramolecular chemistry; metal ions; recognition; binding; perspectives
AB MOLECULES at perform logic operations are prerequisites for molecular information processing and computation1-11. We12,13 and others14-16 have previously reported receptor molecules that can be considered to perform simple logic operations by coupling ionic bonding or more complex molecular-recognition processes with photonic (fluorescence) signals: in these systems, chemical binding (the 'input') results in a change in fluorescence intensity (the 'output') from the receptor. Here we describe a receptor (molecule (1) in Fig. 1) that operates as a logic device with two input channels: the fluorescence signal depends on whether the molecule binds hydrogen ions, sodium ions or both. The input/output characteristics of this molecular device correspond to those of an AND gate.
RP DE SILVA, AP (corresponding author), QUEENS UNIV BELFAST, SCH CHEM, BELFAST BT9 5AG, ANTRIM, NORTH IRELAND.
NR 30
TC 1148
Z9 1202
U1 2
U2 236
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 42
EP 44
DI 10.1038/364042a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800050
DA 2026-03-10
ER

PT J
AU KIM, KJ
   LI, B
   WINER, J
   ARMANINI, M
   GILLETT, N
   PHILLIPS, HS
   FERRARA, N
AF KIM, KJ
   LI, B
   WINER, J
   ARMANINI, M
   GILLETT, N
   PHILLIPS, HS
   FERRARA, N
TI INHIBITION OF VASCULAR ENDOTHELIAL GROWTH FACTOR-INDUCED ANGIOGENESIS SUPPRESSES TUMOR-GROWTH INVIVO
SO NATURE
LA English
DT Article
ID permeability factor; cell mitogen
AB THE development of new blood vessels (angiogenesis) is required for many physiological processes including embryogenesis, wound healing and corpus luteum formation1,2. Blood vessel neoformation is also important in the pathogenesis of many disorders1-5, particularly rapid growth and metastasis of solid tumours3-5. There are several potential mediators of tumour angiogenesis, including basic and acidic fibroblast growth factors, tumour necrosis factor-alpha and transforming factors-alpha and -beta1,2. But it is unclear whether any of these agents actually mediates angiogenesis and tumour growth in vivo. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen and an angiogenesis inducer released by a variety of tumour cells and expressed in human tumours in situ. To test whether VEGF may be a tumour angiogenesis factor in vivo, we injected human rhabdomyosarcoma, glioblastoma multiforme or leiomyosarcoma cell lines into nude mice. We report here that treatment with a monoclonal antibody specific for VEGF inhibited the growth of the tumours, but had no effect on the growth rate of the tumour cells in vitro. The density of vessels was decreased in the antibody-treated tumours. These findings demonstrate that inhibition of the action of an angiogenic factor spontaneously produced by tumour cells may suppress tumour growth in vivo.
C1 GENENTECH INC,460 POINT SAN BRUNO BLVD,S SAN FRANCISCO,CA 94080.
C3 Roche Holding; Roche Holding USA; Genentech
NR 32
TC 3199
Z9 3922
U1 2
U2 229
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 841
EP 844
DI 10.1038/362841a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300057
PM 7683111
DA 2026-03-10
ER

PT J
AU MIYAZAKI, K
   HASEGAWA, M
   FUNAHASHI, K
   UMEDA, M
AF MIYAZAKI, K
   HASEGAWA, M
   FUNAHASHI, K
   UMEDA, M
TI A METALLOPROTEINASE INHIBITOR DOMAIN IN ALZHEIMER AMYLOID PROTEIN-PRECURSOR
SO NATURE
LA English
DT Article
ID basement-membrane collagen; nexin-ii; disease; cells; cleavage
AB EXTRACELLULAR deposition of amyloid beta-protein (beta-AP), or A4 protein (M(r) 4,000), is associated with Alzheimer's disease and with Down's syndrome (trisomy for chromosome 21)1-3. The large membrane-bound precursor protein (APP) of beta-AP is normally cleaved within the beta-AP region by a putative proteinase (APP secretase) to release its extracellular portion; beta-AP is produced by an alternative proteolytic processing4-6. Here we demonstrate that APP contains a proteinase inhibitor domain for the matrix metalloproteinase gelatinase A, which is located in the C-terminal glycosylated region of the secretory forms of APP. In addition, we show that the gelatinase has an APP secretase-like activity, which hydrolyses the Lys16-Leu17 bond in the beta-AP sequence. Our results indicate that the proteinase inhibitor domain of APP and gelatinase A may be involved in the formation of beta-AP.
RP MIYAZAKI, K (corresponding author), YOKOHAMA CITY UNIV,KIHARA INST BIOL RES,DIV CELL BIOL,2-120-3 NAKAMURA CHO,MINAMI KU,YOKOHAMA,KANAGAWA 232,JAPAN.
NR 25
TC 165
Z9 172
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 839
EP 841
DI 10.1038/362839a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300056
PM 8479521
DA 2026-03-10
ER

PT J
AU PAREKH, AB
   TERLAU, H
   STUHMER, W
AF PAREKH, AB
   TERLAU, H
   STUHMER, W
TI DEPLETION OF INSP3 STORES ACTIVATES A CA2+ AND K+ CURRENT BY MEANS OF A PHOSPHATASE AND A DIFFUSIBLE MESSENGER
SO NATURE
LA English
DT Article
ID xenopus oocytes; inositol phosphates; calcium entry; receptor; phosphorylation; resolution; injection; serotonin; proteins; channel
AB IN non-excitable cells, release of Ca2+ from the inositol 1,4,5-trisphosphate (InsP3)-sensitive store can activate Ca2+ entry1-3. Very little is known about the signal mechanism relating store emptying to plasma membrane Ca2+ influx. It has been suggested that the signal may be either a diffusible messenger like an inositol phosphate4, or the InsP3 receptor itself, which, by physically coupling to some component of Ca2+ entry in the plasma membrane, may link store release to Ca2+ entry5. The nature of the Ca2+ entry pathway is also unclear. Only in mast cells has a very selective Ca2+ current been observed after store emptying6. Activation of exogenous 5-hydroxytryptamine (5-HT) receptors expressed in Xenopus oocytes or direct injection of InsP3 evokes Ca2+ entry activated by InsP3 pool depletion7. Here we investigate the nature of this influx pathway and find a current activated by pool depletion. This has an unusual selectivity in that it is more permeable to Ca2+ ions than to other divalent cations (Ba2+, Sr2+ or Mn2+). Moreover, a K+ permeability is also stimulated after pool depletion. The activation of this store depletion current involves both a phosphatase and an unidentified diffusible messenger. Both the Ca2+ entry pathway and the activating factors found here may be relevant to pool-depleted Ca2+ entry in a variety of non-excitable cells.
C1 MAX PLANCK INST EXPTL MED,DEPT MOLEC BIOL NEURONAL SIGNALS,D-37077 GOTTINGEN,GERMANY.
C3 Max Planck Society
RP PAREKH, AB (corresponding author), MAX PLANCK INST BIOPHYS CHEM,DEPT MEMBRANE BIOPHYS,FASSBERG POB 2841,D-37077 GOTTINGEN,GERMANY.
NR 28
TC 379
Z9 390
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 814
EP 818
DI 10.1038/364814a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100059
PM 8395025
DA 2026-03-10
ER

PT J
AU PARKER, R
   SILICIANO, PG
AF PARKER, R
   SILICIANO, PG
TI EVIDENCE FOR AN ESSENTIAL NON-WATSON-CRICK INTERACTION BETWEEN THE 1ST AND LAST NUCLEOTIDES OF A NUCLEAR PREMESSENGER RNA INTRON
SO NATURE
LA English
DT Article
ID 3' splice-site; mammalian introns; yeast; u6; ribonucleoprotein; mutations; recognition; tetrahymena; sequences; u2
AB NUCLEAR pre-messenger RNA splicing requires the action of five small nuclear (sn) RNAs, U1, U2, U4, U5 and U6, and more than 50 proteins1,2. The mechanistic similarity of nuclear pre-mRNA splicing and group II self-splicing suggests that many of the central processes of nuclear pre-mRNA splicing are based on RNA-RNA interactions3,4. To understand the mechanism of pre-mRNA splicing, the interactions, and their temporal relationships, that occur between the snRNAs and the pre-mRNA during splicing must be identified. Several snRNA-snRNA5-9 and snRNA-intron9-12 interactions have been demonstrated but the putative RNA-based interactions that recognize the AG dinucleotide at the 3' splice site during 3' cleavage and exon ligation are unknown. We report here the reciprocal suppression between 5' and 3' splice site mutations in the yeast actin intron, and propose that the 3' splice site is positioned for 3' cleavage and exon ligation, at least in part, through a non-Watson-Crick interaction between the guanosines at the 5' and 3' splice sites.
C1 UNIV MINNESOTA, SCH MED, INST HUMAN GENET, MINNEAPOLIS, MN 55455 USA.
   UNIV MINNESOTA, SCH MED, DEPT BIOCHEM, MINNEAPOLIS, MN 55455 USA.
C3 University of Minnesota System; University of Minnesota Twin Cities; University of Minnesota System; University of Minnesota Twin Cities
RP PARKER, R (corresponding author), UNIV ARIZONA, DEPT MOLEC & CELLULAR BIOL, LIFE SCI S, TUCSON, AZ 85721 USA.
NR 29
TC 134
Z9 144
U1 0
U2 4
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 660
EP 662
DI 10.1038/361660a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600071
PM 8437627
DA 2026-03-10
ER

PT J
AU ROSMAN, KJR
   CHISHOLM, W
   BOUTRON, CF
   CANDELONE, JP
   GORLACH, U
AF ROSMAN, KJR
   CHISHOLM, W
   BOUTRON, CF
   CANDELONE, JP
   GORLACH, U
TI ISOTOPIC EVIDENCE FOR THE SOURCE OF LEAD IN GREENLAND SNOWS SINCE THE LATE 1960S
SO NATURE
LA English
DT Article
ID atmospheric lead; pollution; sediments; tracers; pond; ice
AB IN 1969, Murozumi et al.1 demonstrated that the concentration of lead in Greenland snow had increased by a factor of 200 since ancient times, and concluded that most of this increase was a result of the use of alkyl-leaded petrol. Partly because of these findings, the United States and other western countries limited the use of lead additives in petrol from about 1970. Recently, Boutron et al.2 showed that the lead concentration in Greenland snow had decreased by a factor of approximately 7.5 over the past 20 years, and suggested that this was a result of the decline in use of leaded petrol. We present here measurements of the Pb-206/Pb-207 ratio of the lead contained in the samples studied by Boutron et al. Because aerosols from the atmosphere above the United States are more radiogenic than those from Eurasia, we can trace the relative contributions of these two sources in the Greenland lead over the period analysed by Boutron et al. We find that the United States was a significant source of lead in the 1970s, but it has since declined considerably in relative importance. This decline mirrors the decrease in use of leaded petrol in the United States, confirming the earlier hypothesis.
C1 CNRS,GLACIOL & GEOPHYS ENVIRONNEMENT LAB,F-38402 ST MARTIN DHERES,FRANCE.
   UNIV GRENOBLE,UFR MECAN,F-38401 GRENOBLE,FRANCE.
C3 Centre National de la Recherche Scientifique (CNRS); Communaute Universite Grenoble Alpes; Universite Grenoble Alpes (UGA)
RP ROSMAN, KJR (corresponding author), CURTIN UNIV TECHNOL,DEPT APPL PHYS,BENTLEY,WA 6102,AUSTRALIA.
NR 17
TC 196
Z9 206
U1 1
U2 28
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 333
EP 335
DI 10.1038/362333a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600056
PM 29634020
DA 2026-03-10
ER

PT J
AU LEVESQUE, AJ
   MAYLE, FE
   WALKER, IR
   CWYNAR, LC
AF LEVESQUE, AJ
   MAYLE, FE
   WALKER, IR
   CWYNAR, LC
TI A PREVIOUSLY UNRECOGNIZED LATE-GLACIAL COLD EVENT IN EASTERN NORTH-AMERICA
SO NATURE
LA English
DT Article
ID late weichselian vegetation; floral migration; rogaland; climate; norway; canada
AB THE transition between the last glacial period and the present interglacial was marked by pronounced and abrupt changes in climate1,2, one of which, the Younger Dryas event, resulted in a return to almost full-glacial conditions. Here we present evidence for a short but intense cold period in eastern North America, pre-dating the Younger Dryas, revealed by analysing the organic, pollen and midge content of lake sediments at very high resolution. We name this event the Killarney Oscillation and it lasted from 11,160 to 10,910 radiocarbon years BP. Because this corresponds to the Gerzensee Oscillation in Switzerland and can be correlated with other short-term events reported from across the North Atlantic seaboard3-14, we conclude that a single event affected all of the North Atlantic region. This pre-Younger Dryas cold period is similar in nature and geographic extent to the major cooling of the Younger Dryas15, raising the possibility that these two events are causally related.
C1 OKANAGAN UNIV COLL,DEPT BIOL,KELOWNA V1Y 4X8,BC,CANADA.
RP LEVESQUE, AJ (corresponding author), UNIV NEW BRUNSWICK,DEPT BIOL,BAG SERVICE NUMBER 45111,FREDERICTON E3B 6E1,NB,CANADA.
NR 19
TC 159
Z9 166
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 623
EP 626
DI 10.1038/361623a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600059
DA 2026-03-10
ER

PT J
AU MULLIGAN, LM
   KWOK, JBJ
   HEALEY, CS
   ELSDON, MJ
   ENG, C
   GARDNER, E
   LOVE, DR
   MOLE, SE
   MOORE, JK
   PAPI, L
   PONDER, MA
   TELENIUS, H
   TUNNACLIFFE, A
   PONDER, BAJ
AF MULLIGAN, LM
   KWOK, JBJ
   HEALEY, CS
   ELSDON, MJ
   ENG, C
   GARDNER, E
   LOVE, DR
   MOLE, SE
   MOORE, JK
   PAPI, L
   PONDER, MA
   TELENIUS, H
   TUNNACLIFFE, A
   PONDER, BAJ
TI GERM-LINE MUTATIONS OF THE RET PROTOONCOGENE IN MULTIPLE ENDOCRINE NEOPLASIA TYPE-2A
SO NATURE
LA English
DT Article
ID point mutation; tyrosine kinase; protooncogene; domain; chromosome-10; carcinomas
AB MULTIPLE endocrine neoplasia type 2A (MEN 2A) is a dominantly inherited cancer syndrome that affects tissues derived from neural ectoderm. It is characterized by medullary thyroid carcinoma (MTC) and phaeochromocytoma1. The MEN2A gene has recently been localized by a combination of genetic and physical mapping techniques to a 480-kilobase region in chromosome 10q11.2 (refs 2,3). The DNA segment encompasses the RET proto-oncogene, a receptor tyrosine kinase gene expressed in MTC and phaeochromocytoma and at lower levels in normal human thyroid4. This suggested RET as a candidate for the MEN2A gene. We have identified missense mutations of the RET proto-oncogene in 20 of 23 apparently distinct MEN 2A families, but not in 23 normal controls. Further, 19 of these 20 mutations affect the same conserved cysteine residue at the boundary of the RET extracellular and transmembrane domains.
C1 UNIV CAMBRIDGE,DEPT PATHOL,CANC RES CAMPAIGN,HUMAN CANC GENET GRP,TENNIS COURT RD,CAMBRIDGE CB2 1QP,ENGLAND.
C3 CRUK Cambridge Institute; University of Cambridge
NR 20
TC 1700
Z9 1795
U1 0
U2 31
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 458
EP 460
DI 10.1038/363458a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800061
PM 8099202
DA 2026-03-10
ER

PT J
AU LOCKNER, DA
   BYERLEE, JD
AF LOCKNER, DA
   BYERLEE, JD
TI HOW GEOMETRICAL CONSTRAINTS CONTRIBUTE TO THE WEAKNESS OF MATURE FAULTS
SO NATURE
LA English
DT Article
ID friction; behavior; fracture; gouge
AB INCREASING evidence that the San Andreas fault has low shear strength1 has fuelled considerable discussion regarding the role of fluid pressure in controlling fault strength. Byerlee2,3 and Rice4 have shown how fluid pressure gradients within a fault zone can produce a fault with low strength while avoiding hydraulic fracture of the surrounding rock due to excessive fluid pressure. It may not be widely realised, however, that the same analysis2-4 shows that even in the absence of fluids, the presence of a relatively soft 'gouge' layer surrounded by harder country rock can also reduce the effective shear strength of the fault. As shown most recently by Byerlee and Savage5, as the shear stress across a fault increases, the stress state within the fault zone evolves to a limiting condition in which the maximum shear stress within the fault zone is parallel to the fault, which then slips with a lower apparent coefficient of friction than the same material unconstrained by the fault. Here we confirm the importance of fault geometry in determining the apparent weakness of fault zones, by showing that the apparent friction on a sawcut granite surface can be predicted from the friction measured in intact rock, given only the geometrical constraints introduced by the fault surfaces. This link between the sliding friction of faults and the internal friction of intact rock suggests a new approach to understanding the microphysical processes that underlie friction in brittle materials.
RP LOCKNER, DA (corresponding author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA.
NR 21
TC 47
Z9 49
U1 1
U2 20
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 250
EP 252
DI 10.1038/363250a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600048
DA 2026-03-10
ER

PT J
AU OKSENBERG, JR
   PANZARA, MA
   BEGOVICH, AB
   MITCHELL, D
   ERLICH, HA
   MURRAY, RS
   SHIMONKEVITZ, R
   SHERRITT, M
   ROTHBARD, J
   BERNARD, CCA
   STEINMAN, L
AF OKSENBERG, JR
   PANZARA, MA
   BEGOVICH, AB
   MITCHELL, D
   ERLICH, HA
   MURRAY, RS
   SHIMONKEVITZ, R
   SHERRITT, M
   ROTHBARD, J
   BERNARD, CCA
   STEINMAN, L
TI SELECTION FOR T-CELL RECEPTOR V-BETA-D-BETA-J-BETA GENE REARRANGEMENTS WITH SPECIFICITY FOR A MYELIN BASIC-PROTEIN PEPTIDE IN BRAIN-LESIONS OF MULTIPLE-SCLEROSIS
SO NATURE
LA English
DT Article
ID nonradioactive oligonucleotide probes; amplified dna; sequence; polymorphism
AB MULTIPLE sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system in which a restricted cellular immune response has been observed. In order to establish whether such T cell responses are likely to be antigen-specific particularly with regard to myelin basic protein (MBP), we analysed T-cell receptor (TCR) gene rearrangements directly from MS brain plaques, using the polymerase chain reaction on reverse transcribed messenger RNA, and compared these with TCR of previously described MBP-specific T cell clones from MS and the rat model experimental allergic encephalomyelitis. Rearranged Vbeta5.2 genes were detected in the brains of all patients who were HLA DRB1*1501, DQA1*0102, DQB1*0602, DPB1*0401. The Vbeta5.2-Dbeta-Jbeta sequences in these MS brain plaques revealed five motifs. One of the common motifs was identical to that described for the VDJ region of a Vbeta5.2 T-cell clone. This clone was from an MS patient who was HLA DRB1*1501, DQB1*0602, DPB1*0401, and it was cytotoxic towards targets containing the MBP peptide 89-106 (ref. 1). The deduced amino-acid sequence of this VDJ rearrangement, Leu-Arg-Gly, has also been described in rat T cells cloned from experimental allergic encephalomyelitis lesions, which are specific for MBP peptide 87-99 (ref. 2). VDJ sequences with specificity for this MBP epitope constitute a large fraction (40%) of the TCR Vbeta5.2 N(D)N rearrangements in MS lesions. The capacity of rat T cells with these VDJ sequences to cause experimental allergic encephalomyelitis2 and the prevalence of such sequences in demyelinated human lesions indicate that T cells with this rearranged TCR may be critical in MS.
C1 ROCHE MOLEC SYST,DEPT HUMAN GENET,EMERYVILLE,CA 94608.
   ROCKY MT MS CTR,ENGLEWOOD,CO 80150.
   LA TROBE UNIV,NEUROIMMUNOL LAB,BUNDOORA,VIC 3083,AUSTRALIA.
   IMMULOG PHARMACEUT CORP,PALO ALTO,CA 94304.
C3 La Trobe University
RP OKSENBERG, JR (corresponding author), STANFORD UNIV,MED CTR,SCH MED,DEPT NEUROL & NEUROL SCI,STANFORD,CA 94305, USA.
NR 18
TC 426
Z9 453
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 68
EP 70
DI 10.1038/362068a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600062
PM 7680433
DA 2026-03-10
ER

PT J
AU MALHOTRA, R
AF MALHOTRA, R
TI THE ORIGIN OF PLUTO PECULIAR ORBIT
SO NATURE
LA English
DT Article
AB THE origin of Pluto's unusual orbit-the most eccentric and inclined of all the planets-remains a mystery. The orbits of Pluto and Neptune overlap, but close approaches of these two planets are prevented by the existence of a resonance condition1: Pluto's orbital period is exactly 3/2 that of Neptune, which ensures that the conjunctions always occur near Pluto's aphelion. Long-term orbit integrations2-5 have uncovered other subtle resonances and near-resonances, and indicate that Pluto's orbit is chaotic yet remains macroscopically stable over billion-year timescales. A suggestion4 that the orbit may have evolved purely by chaotic dynamics appears unlikely in light of recent orbital stability studies6, unless one appeals to a well-timed collision to place Pluto in its stable orbit19. Here I show that Pluto could have acquired its current orbit during the late stages of planetary accretion, when the jovian planets underwent significant orbital migration as a result of encounters with residual planetesimals7. As Neptune moved outwards, a small body like Pluto in an initially circular orbit could have been captured into the 3:2 resonance, following which its orbital eccentricity would rise rapidly to its current Neptune-crossing value.
RP MALHOTRA, R (corresponding author), LUNAR & PLANETARY INST,3600 BAY AREA BLVD,HOUSTON,TX 77058, USA.
NR 19
TC 375
Z9 421
U1 1
U2 14
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 819
EP 821
DI 10.1038/365819a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100043
DA 2026-03-10
ER

PT J
AU LUSSO, P
   MALNATI, MS
   GARZINODEMO, A
   CROWLEY, RW
   LONG, EO
   GALLO, RC
AF LUSSO, P
   MALNATI, MS
   GARZINODEMO, A
   CROWLEY, RW
   LONG, EO
   GALLO, RC
TI INFECTION OF NATURAL-KILLER-CELLS BY HUMAN HERPESVIRUS-6
SO NATURE
LA English
DT Article
ID chronic fatigue syndrome; human-immunodeficiency-virus; invitro; aids; deficiency; mechanism; antigen
AB NATURAL killer (NK) cells are a functionally defined subset of non-T, non-B lymphocytes of bone marrow origin, which induce lysis of selected target cells, including neoplastic and virus-infected cells1-3. The NK cell function provides an important mechanism of primary defence against viruses in vivo, as demonstrated by the occurrence of multiple herpesvirus infections in patients congenitally lacking NK cells4,5. Here we show that functionally competent CD3- NK clones can be productively infected by human herpesvirus 6 (HHV-6)6, a T-lymphotropic DNA virus7 that may play a role in the acquired immunodeficiency syndrome (AIDS)8 and in the chronic fatigue syndrome9, two disorders associated with a defective NK cell activity10-15. The infection is cytopathic and induces de novo expression of CD4, an antigen not expressed within the NK lineage16,17, thereby predisposing NK cells to infection by human immunodeficiency virus type 1 (HIV-1). These results provide evidence that a herpesvirus can directly target and kill NK cells, a potential strategy to suppress the natural anti-viral immunity of the host.
C1 NIAID, IMMUNOGENET LAB, BETHESDA, MD 20892 USA.
C3 National Institutes of Health (NIH) - USA; NIH National Institute of Allergy & Infectious Diseases (NIAID)
RP LUSSO, P (corresponding author), NCI, TUMOR CELL BIOL LAB, BETHESDA, MD 20892 USA.
NR 29
TC 177
Z9 187
U1 0
U2 3
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 458
EP 462
DI 10.1038/362458a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400087
PM 7681936
DA 2026-03-10
ER

PT J
AU PARMA, J
   DUPREZ, L
   VANSANDE, J
   COCHAUX, P
   GERVY, C
   MOCKEL, J
   DUMONT, J
   VASSART, G
AF PARMA, J
   DUPREZ, L
   VANSANDE, J
   COCHAUX, P
   GERVY, C
   MOCKEL, J
   DUMONT, J
   VASSART, G
TI SOMATIC MUTATIONS IN THE THYROTROPIN RECEPTOR GENE CAUSE HYPERFUNCTIONING THYROID ADENOMAS
SO NATURE
LA English
DT Article
ID g-protein; tsh receptor; alpha-1b-adrenergic receptor; cell-proliferation; cyclic-amp; autoantibody; nodules; tumors; binding; region
AB THE pituitary hormone thyrotropin stimulates the function, expression of differentiation and growth of thyrocytes by cyclic AMP-dependent mechanisms1-3. Tissue hyperplasia and hyperthyroidism are therefore expected to result when activation of the adenylyl cyclase-cAMP cascade is unregulated. This is observed in several situations4,5, including when somatic mutations impair the GTPase activity of the G protein G(salpha) (refs 6, 7). Such a mechanism is probably responsible for the development of a minority, of monoclonal hyperfunctioning thyroid adenomas6,8,9. Here we identify somatic mutations in the carboxy-terminal portion of the third cytoplasmic loop of the thyrotropin receptor in three out of eleven hyperfunctioning thyroid adenomas. These mutations are restricted to tumour tissue and involve two different residues (aspartic acid at position 619 to glycine in two cases, and alanine at position 623 to isoleucine in one case). The mutant receptors confer constitutive activation of adenylyl cyclase when tested by transfection in COS cells. This shows that G-protein-coupled receptors are susceptible to constitutive activation by spontaneous somatic mutations10,11 and may thus behave as proto-oncogenes.
C1 UNIV LIBRE BRUXELLES,FAC MED,SERV GENET MED,B-1070 BRUSSELS,BELGIUM.
C3 Universite Libre de Bruxelles
RP PARMA, J (corresponding author), UNIV LIBRE BRUXELLES,FAC MED,INST RECH INTERDISCIPLINAIRE,CAMPUS ERASME,808 ROUTE LENNIK,B-1070 BRUSSELS,BELGIUM.
NR 26
TC 853
Z9 915
U1 0
U2 27
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 649
EP 651
DI 10.1038/365649a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600059
PM 8413627
DA 2026-03-10
ER

PT J
AU SOMMER, RJ
   TAUTZ, D
AF SOMMER, RJ
   TAUTZ, D
TI INVOLVEMENT OF AN ORTHOLOGUE OF THE DROSOPHILA PAIR-RULE GENE HAIRY IN SEGMENT FORMATION OF THE SHORT GERM-BAND EMBRYO OF TRIBOLIUM (COLEOPTERA)
SO NATURE
LA English
DT Article
ID molecular-genetics; kruppel; expression; reveals; hunchback; homology; pattern; gap; dna
AB THE segments in long germ-band insect embryos, like Drosophila, are all determined at syncytial blastoderm stage. This is in contrast to short germ-band embryos which show an early determination of only the anterior head segments, whereas the more posterior thoracic and abdominal segments are sequentially added after formation of a primary germ anlage (reviewed in ref. 1). Segment formation in Drosophila involves the pair-rule genes which define double segmental periodicities2,3 and which have been considered to represent a special adaptation to the long germ-band type development4,5 hairy belongs to the primary pair-rule genes in Drosophila which are directly regulated by the gap genes, such as Kruppel6-13. We have isolated the orthologues of hairy and Kruppel from the flour beetle Tribolium castaneum which has a short germ type development14. We show here that hairy is expressed in several stripes at blastoderm stage and later on in two stripes in the growth zone of the developing embryo. Kruppel expression overlaps hairy stripe three and four expression, very similar to Drosophila. This suggests that the segment patterning mechanism that acts in an open blastoderm in Drosophila works in a similar way in the cellularized Tribolium embryo.
C1 UNIV MUNICH,INST ZOOL,W-8000 MUNICH 2,GERMANY.
C3 University of Munich
NR 28
TC 144
Z9 156
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 448
EP 450
DI 10.1038/361448a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300060
PM 8429884
DA 2026-03-10
ER

PT J
AU DEHAY, C
   GIROUD, P
   BERLAND, M
   SMART, I
   KENNEDY, H
AF DEHAY, C
   GIROUD, P
   BERLAND, M
   SMART, I
   KENNEDY, H
TI MODULATION OF THE CELL-CYCLE CONTRIBUTES TO THE PARCELLATION OF THE PRIMATE VISUAL-CORTEX
SO NATURE
LA English
DT Article
ID cortical areas; neocortex; neurons; monkey; specification; brain; rat
AB AN as-vet unresolved issue in developmental neurobiology is whether the discrete areas that form the mammalian cortex emerge from a uniform cortical plate or whether they are already specified in the germinal zone1,2. A feature of the primate striate cortex is that the number of neurons per unit area is twice that of anywhere else in the cerebral cortex3. Here we take advantage of this unique structural feature to investigate whether the extra striate cortical cells are due to increased neuron production during neurogenesis. We labelled precursors undergoing terminal cell division with H-3-thymidine and allowed them to migrate to the cortical plate. Cell counts revealed that their rate of production in the germinal zone of striate cortex is higher than in that giving rise to extrastriate cortex. Also, we used H-3-thymidine pulse injections to investigate cell cycle dynamics and found that this phase of increased production of striate cortical cells is associated with changes in the parameters of the cell cycle. These results show that cortical area identity is at least partially determined at the level of the ventricular zone.
C1 INSERM,U371,18 AVE DOYEN LEPINE,F-69500 BRON,FRANCE.
   HOP CLAUDE BERNARD,FAC MED LYON NORD,SERV GYNECOL & OBSTET,F-69600 OULLINS,FRANCE.
   UNIV DUNDEE,DUNDEE DD1 4HN,SCOTLAND.
C3 Institut National de la Sante et de la Recherche Medicale (Inserm); University of Dundee
NR 26
TC 126
Z9 135
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 464
EP 466
DI 10.1038/366464a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800064
PM 8247154
DA 2026-03-10
ER

PT J
AU WHITING, GJ
   CHANTON, JP
AF WHITING, GJ
   CHANTON, JP
TI PRIMARY PRODUCTION CONTROL OF METHANE EMISSION FROM WETLANDS
SO NATURE
LA English
DT Article
ID co2 exchange; spartina-alterniflora; belowground biomass; arctic tundra; rice paddy; atmosphere; vegetation; transport; soil; methanogenesis
AB WETLANDS, both natural and agricultural, contribute an estimated 40 to 50% of the total methane emitted to the atmosphere each year. Recent efforts in atmospheric modelling1 and attempts to constrain CH4 source strengths2 have indicated the need to delineate the processes responsible for the large variations in emission rates found within and across wetland types. Numerous biogeochemical factors are known to affect the activity of methanogenic bacteria3,4 and although there has been some success in relating water level5-7 and temperature8,9 to CH4 emissions within particular systems, these variables are insufficient for predicting emissions across a variety of wetlands2,10. From simultaneous measurements of CO2 and CH4 exchange in wetlands extending from subarctic peatlands to subtropical marshes, we report here a positive correlation between CH4 emission and net ecosystem production and suggest that net ecosystem production is a master variable, integrating many factors which control CH4 emission in vegetated wetlands. We find that about 3 per cent of the daily net ecosystem production is emitted back to the atmosphere as CH4. With projected stimulation of primary production and soil microbial activity in wetlands associated with elevated atmospheric CO2 concentrations11, we envisage the potential for increasing CH4 emissions from inundated wetlands, further enhancing the greenhouse effect.
C1 NASA,LANGLEY RES CTR,SAIC,HAMPTON,VA 23681.
   FLORIDA STATE UNIV,DEPT OCEANOG,TALLAHASSEE,FL 32306.
C3 National Aeronautics & Space Administration (NASA); NASA Langley Research Center; Science Applications International Corporation (SAIC); State University System of Florida; Florida State University
NR 41
TC 626
Z9 738
U1 4
U2 391
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 794
EP 795
DI 10.1038/364794a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100053
DA 2026-03-10
ER

PT J
AU TISCH, R
   YANG, XD
   SINGER, SM
   LIBLAU, RS
   FUGGER, L
   MCDEVITT, HO
AF TISCH, R
   YANG, XD
   SINGER, SM
   LIBLAU, RS
   FUGGER, L
   MCDEVITT, HO
TI IMMUNE-RESPONSE TO GLUTAMIC-ACID DECARBOXYLASE CORRELATES WITH INSULITIS IN NONOBESE DIABETIC MICE
SO NATURE
LA English
DT Article
ID mouse; identification; autoantigen; products; antibody; cloning
AB KNOWING the autoantigen target(s) in an organ-specific autoimmune disease is essential to understanding its pathogenesis. Insulin-dependent diabetes mellitus (IDDM) is an autoimmune disease characterized by lymphocytic infiltration of the islets of Langerhans (insulitis) and destruction of insulin-secreting pancreatic beta-cells1. Several beta-cell proteins have been identified as autoantigens, but their importance in the diabetogenic process is not known2. The non-obese diabetic (NOD) mouse is a murine model for spontaneous IDDM3.  Here we determine the temporal sequence of T-cell and antibody responses in NOD mice to a panel of five murine beta-cell antigens and find that antibody and T-cell responses specific for the two isoforms of glutamic acid decarboxylase (GAD) are first detected in 4-week-old NOD mice. This GAD-specific reactivity coincides with the earliest detectable response to an islet extract, and with the onset of insulitis. Furthermore, NOD mice receiving intrathymic injections of GAD65 exhibit markedly reduced T-cell proliferative responses to GAD and to the rest of the panel, in addition to remaining free of diabetes. These results indicate that the spontaneous response to beta-cell antigens arises very early in life and that the anti-GAD immune response has a critical role in the disease process during this period.
C1 STANFORD UNIV,MED CTR,DEPT MED,STANFORD,CA 94305.
C3 Stanford University
RP TISCH, R (corresponding author), STANFORD UNIV,MED CTR,DEPT MICROBIOL & IMMUNOL,STANFORD,CA 94305, USA.
NR 19
TC 936
Z9 1006
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 72
EP 75
DI 10.1038/366072a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700057
PM 8232539
DA 2026-03-10
ER

PT J
AU TANG, AM
   AMAGAI, M
   GRANGER, LG
   STANLEY, JR
   UDEY, MC
AF TANG, AM
   AMAGAI, M
   GRANGER, LG
   STANLEY, JR
   UDEY, MC
TI ADHESION OF EPIDERMAL LANGERHANS CELLS TO KERATINOCYTES MEDIATED BY E-CADHERIN
SO NATURE
LA English
DT Article
ID dendritic cells; bone-marrow; molecules; family; expression; differentiation; glycoprotein; desmocollins; desmoglein; member
AB LANGERHANS cells (LC) are the principal accessory cells present in epidermis1. Because LC have limited capacity for self-renewal2, epidermis is continually repopulated by as-yet uncharacterized bone marrow-derived LC progenitors3,4. In addition, although LC persist in epidermis for extended periods, LC are induced to migrate from skin to regional lymph nodes after antigen exposure5. To begin to elucidate mechanisms involved in LC trafficking, we characterized LC-keratinocyte (KC) interactions. Here we report that fresh murine LC express cadherins, and that LC adhere to KC in vitro through E-cadherin. Cultured LC (which may bear a phenotypic and functional relationship to LC that have migrated to lymph nodes6,7) express lower levels of E-cadherin and exhibit decreased affinity for KC. These results suggest that expression of E-cadherin by LC promotes persistence of these cells in epidermis, and that cadherins may play important and unanticipated roles in interactions between leukocytes and epithelia.
C1 NCI,DERMATOL BRANCH,BETHESDA,MD 20892.
   NCI,EXPTL IMMUNOL BRANCH,BETHESDA,MD 20892.
C3 National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI); National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI)
NR 29
TC 425
Z9 468
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 82
EP 85
DI 10.1038/361082a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800054
PM 8421498
DA 2026-03-10
ER

PT J
AU PETROV, V
   GASPAR, V
   MASERE, J
   SHOWALTER, K
AF PETROV, V
   GASPAR, V
   MASERE, J
   SHOWALTER, K
TI CONTROLLING CHAOS IN THE BELOUSOV-ZHABOTINSKY REACTION
SO NATURE
LA English
DT Article
ID oscillations; impurity; system
AB DETERMINISTIC chaos is characterized by long-term unpredictability arising from an extreme sensitivity to initial conditions. Such behaviour may be undesirable, particularly for processes dependent on temporal regulation. On the other hand, a chaotic system can be viewed as a virtually unlimited reservoir of periodic behaviour which may be accessed when appropriate feedback is applied to one of the system parameters1. Feedback algorithms have now been successfully applied to stabilize periodic oscillations in chaotic laser2, diode3, hydrodynamic4 and magnetoelastic5 systems, and more recently in myocardial tissue6. Here we apply a map-based, proportional-feedback algorithm7,8 to stabilize periodic behaviour in the chaotic regime of an oscillatory chemical system: the Belousov-Zhabotinsky reaction.
C1 W VIRGINIA UNIV,DEPT CHEM,MORGANTOWN,WV 26506.
   LAJOS KOSSUTH UNIV,DEPT PHYS CHEM,H-4010 DEBRECEN,HUNGARY.
C3 West Virginia University; University of Debrecen
NR 17
TC 377
Z9 406
U1 0
U2 105
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 240
EP 243
DI 10.1038/361240a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400052
DA 2026-03-10
ER

PT J
AU QUELLER, DC
   STRASSMANN, JE
   SOLIS, CR
   HUGHES, CR
   DELOACH, DM
AF QUELLER, DC
   STRASSMANN, JE
   SOLIS, CR
   HUGHES, CR
   DELOACH, DM
TI A SELFISH STRATEGY OF SOCIAL INSECT WORKERS THAT PROMOTES SOCIAL COHESION
SO NATURE
LA English
DT Article
ID sex-ratios; genetic relatedness; evolution; queens; wasps
AB SOCIAL insect colonies are in many ways analogous to organisms1, because kin-selected workers act selflessly and cohesively to promote the fitness of a few reproductive members2,3. But workers can evolve selfish strategies which create reproductive conflict, reducing the functional integrity of colonies. For example, they can lay unfertilized (male) eggs3-6, compete directly with the queen to lay fertilized (female) eggs7, suppress the reproduction of other workers8,9, choose among several queens10 and generally favour closer over more distant kin11. Conflicts over the sex ratio may be especially pervasive, even in highly eusocial insects. The unusually high relatedness (r = 3/4) of female hymenopteran workers to their full sisters means that workers should prefer more female-biased sex ratios than do queens4. The worker preference for females should be exerted most strongly on colonies where they are most likely to be full sisters, leaving male production to colonies where this advantage least applies4,12-14; this prediction is supported by studies in ants and bees12,15-17. Here we show that when colonies have multiple queens born in the same nest, the selfish worker sex-ratio strategy has a paradoxical side-effect which strongly promotes social cohesion. This strategy accounts for the peculiar colony cycle of epiponine wasps, and may be responsible for the maintenance of eusociality in this group.
RP QUELLER, DC (corresponding author), RICE UNIV,DEPT ECOL & EVOLUT,POB 1892,HOUSTON,TX 77251, USA.
NR 33
TC 92
Z9 93
U1 0
U2 14
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 639
EP 641
DI 10.1038/365639a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600056
DA 2026-03-10
ER

PT J
AU WINSLOW, JT
   HASTINGS, N
   CARTER, CS
   HARBAUGH, CR
   INSEL, TR
AF WINSLOW, JT
   HASTINGS, N
   CARTER, CS
   HARBAUGH, CR
   INSEL, TR
TI A ROLE FOR CENTRAL VASOPRESSIN IN PAIR BONDING IN MONOGAMOUS PRAIRIE VOLES
SO NATURE
LA English
DT Article
ID neurohypophyseal peptides; microtus-ochrogaster; sexual-behavior; male-rats; oxytocin; receptor; antagonists; system
AB MONOGAMOUS social organization is characterized by selective affiliation with a partner, high levels of paternal behaviour and, in many species, intense aggression towards strangers for defence of territory, nest and mate1,2. Although much has been written about the evolutionary causes of monogamy, little is known about the proximate mechanisms for pair bonding in monogamous mammals2,3.  The prairie vole, Microtus ochrogaster, is a monogamous, biparental rodent which exhibits long-term pair bonds characterized by selective affiliation (partner preference) and aggression4,5.  Here we describe the rapid development of both selective aggression and partner preferences following mating in the male of this species. We hypothesized that either arginine-vasopressin (AVP) or oxytocin (OT), two nine-amino-acid neuropeptides with diverse forebrain projections, could mediate the development of selective aggression and affiliation. This hypothesis was based on the following observations: (1) monogamous and polygamous voles differ specifically in the distribution of forebrain AVP and OT receptors6,7; (2) AVP innervation in the prairie vole brain is sexually dimorphic and important for paternal behaviour8; (3) central AVP pathways have been previously implicated in territorial displays and social memory9,10; and (4) central OT pathways have been previously implicated in affiliative behaviours11. We now demonstrate that central AVP is both necessary and sufficient for selective aggression and partner preference formation, two critical features of pair bonding in the monogamous prairie vole.
C1 NIMH,NEUROPHYSIOL LAB,POB 608,POOLESVILLE,MD 20837.
   UNIV MARYLAND,DEPT ZOOL,COLL PK,MD 20742.
C3 National Institutes of Health (NIH) - USA; NIH National Institute of Mental Health (NIMH); University System of Maryland; University of Maryland College Park
NR 27
TC 741
Z9 855
U1 0
U2 153
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 545
EP 548
DI 10.1038/365545a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100053
PM 8413608
DA 2026-03-10
ER

PT J
AU GREENFIELD, MD
   ROIZEN, I
AF GREENFIELD, MD
   ROIZEN, I
TI KATYDID SYNCHRONOUS CHORUSING IS AN EVOLUTIONARILY STABLE OUTCOME OF FEMALE CHOICE
SO NATURE
LA English
DT Article
ID parasitoid fly; behavior; firefly; predation
AB IN many animals that use rhythmic acoustic or bioluminescent sexual communication, neighbouring males precisely synchronize their signals1-4. This event has previously been interpreted as a development whereby cooperative individuals benefit from maintenance of species-specific signalling rates5,6, minimization of pre dation risks7,8, or maximization of peak signal amplitude of a local population2,9. Our recent findings on chorusing in the neotropical katvdid Neoconocephalus spiza (Orthoptera: Tettigoniidae), however, refute for this species all three hypotheses that claim that synchrony is adaptive. Instead, we demonstrate that synchrony can be an epiphenomenon created by competitive interactions between males jamming each other's signals. The mechanism generating this interference is shown to be an evolutionarily stable strategy (ESS) maintained under sexual selection for exploiting a critical psychoacoustic feature: females orienting toward signalling males choose the leading call in a closely synchronized sequence.
C1 UNIV CALIF LOS ANGELES, DEPT COMP SCI, LOS ANGELES, CA 90024 USA.
C3 University of California System; University of California Los Angeles
RP GREENFIELD, MD (corresponding author), UNIV KANSAS, DEPT ENTOMOL, LAWRENCE, KS 66045 USA.
NR 27
TC 162
Z9 176
U1 0
U2 17
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 618
EP 620
DI 10.1038/364618a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100050
DA 2026-03-10
ER

PT J
AU RAMING, K
   KRIEGER, J
   STROTMANN, J
   BOEKHOFF, I
   KUBICK, S
   BAUMSTARK, C
   BREER, H
AF RAMING, K
   KRIEGER, J
   STROTMANN, J
   BOEKHOFF, I
   KUBICK, S
   BAUMSTARK, C
   BREER, H
TI CLONING AND EXPRESSION OF ODORANT RECEPTORS
SO NATURE
LA English
DT Article
ID beta-adrenergic receptors; 2nd messenger pathways; infected insect cells; signal transduction
AB MYRIADS of odorous molecules that vary widely in structure are nevertheless readily detected and discriminated by the sense of smell, but how this is achieved by the olfactory system has been a long-standing puzzle. Several different models have been proposed1, and previous observations indicate that the recognition sites for odorous molecules could be G-protein-coupled receptor proteins2-4, an idea supported by the discovery of a new gene family that probably encodes a diversity of odorant receptors5. Here we report the identification of new members of the gene family encoding putative odorant receptors and demonstrate that they are indeed transcribed in olfactory receptor neurons. Furthermore, the receptor-encoding complementary DNA is expressed in non-neuronal surrogate cells, which generate second messenger responses upon stimulation with appropriate odorants, indicating that the receptors recognize odorants and couple to G proteins of the host cells.
C1 UNIV STUTTGART,INST ZOOPHYSIOL,GARBENSTR 30,W-7000 STUTTGART 70,GERMANY.
C3 University of Stuttgart
NR 25
TC 254
Z9 291
U1 0
U2 23
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 353
EP 356
DI 10.1038/361353a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000058
PM 7678922
DA 2026-03-10
ER

PT J
AU JUNGMANN, J
   REINS, HA
   SCHOBERT, C
   JENTSCH, S
AF JUNGMANN, J
   REINS, HA
   SCHOBERT, C
   JENTSCH, S
TI RESISTANCE TO CADMIUM MEDIATED BY UBIQUITIN-DEPENDENT PROTEOLYSIS
SO NATURE
LA English
DT Article
ID conjugating enzymes; protein-degradation; yeast; cloning; gene; encodes
AB CADMIUM is a potent poison for living cells. In man, chronic exposure to low levels of cadmium results in damage to kidneys and has been linked to neoplastic disease and ageing, and acute exposure can cause damage to a variety of organs and tissues1. Cadmium reacts with thiol groups and can substitute for zinc in certain proteins2, but the reason for its toxicity in vivo remains uncertain. In eukaryotes, an important selective proteolysis pathway for the elimination of abnormal proteins that are generated under normal or stress conditions is ATP-dependent and mediated by the ubiquitin system3-5. Substrates of this pathway are first recognized by ubiquitin-conjugating enzymes5-7 (or auxiliary factors) which covalently attach ubiquitin, a small and highly conserved protein, to specific internal lysine residues of proteolytic substrates. Ubiquitinated substrates are then degraded by the proteasome, a multisubunit protease complex 8-10. Here we show that expression of this ubiquitin-dependent proteolysis pathway in yeast is activated in response to cadmium exposure and that mutants deficient in specific ubiquitin-conjugating enzymes are hypersensitive to cadmium. Moreover, mutants in the proteasome are hypersensitive to cadmium, suggesting that cadmium resistance is mediated in part by degradation of abnormal proteins. This indicates that a major reason for cadmium toxicity may be cadmium-induced formation of abnormal proteins.
C1 MAX PLANCK GESELL,FRIEDRICH MIESCHER LAB,SPEMANNSTR 37-39,W-7400 TUBINGEN,GERMANY.
   UNIV BAYREUTH,INST PFLANZENPHYSIOL,W-8580 BAYREUTH,GERMANY.
C3 Eberhard Karls University of Tubingen; Max Planck Society; University of Bayreuth
NR 24
TC 241
Z9 258
U1 0
U2 19
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 369
EP 371
DI 10.1038/361369a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000063
PM 8381213
DA 2026-03-10
ER

PT J
AU ROMBERG, L
   VALE, RD
AF ROMBERG, L
   VALE, RD
TI CHEMOMECHANICAL CYCLE OF KINESIN DIFFERS FROM THAT OF MYOSIN
SO NATURE
LA English
DT Article
ID muscle-contraction; dynein; microtubules; mechanism; molecules; movement; motility; systems; atpase
AB MOTOR proteins move unidirectionally along cytoskeletal polymers by coupling translocation to cycles of ATP hydrolysis. The energy from ATP is required both to generate force and to dissociate the motor-filament complex in order to begin a new chemomechanical cycle1,2. For myosin, force production is associated with phosphate release following ATP hydrolysis, whereas dissociation of actomyosin is tightly coupled to the binding of ATP3. Dynein, a microtubule motor, uses a similar cycle4, suggesting that all cytoskeletal motors might operate by a common mechanism. Here we investigate kinesin's chemomechanical cycle by assaying microtubule movement by single kinesin molecules when intermediate states in the hydrolysis cycle are prolonged with ATP analogues or inhibitors. In contrast to myosin and dynein, kinesin with bound ADP dissociates from microtubules during translocation, whereas kinesin with unhydrolysed nucleotide remains tightly associated with the polymer. These findings imply that kinesin converts ATP energy into mechanical work by a pathway distinct from that of myosin or dynein.
C1 UNIV CALIF SAN FRANCISCO,DEPT PHARMACOL,SAN FRANCISCO,CA 94143.
   UNIV CALIF SAN FRANCISCO,DEPT BIOCHEM,SAN FRANCISCO,CA 94143.
C3 University of California System; University of California San Francisco; University of California System; University of California San Francisco
NR 20
TC 92
Z9 103
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 168
EP 170
DI 10.1038/361168a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600064
PM 8421522
DA 2026-03-10
ER

PT J
AU OGELMAN, H
   ORIO, M
   KRAUTTER, J
   STARRFIELD, S
AF OGELMAN, H
   ORIO, M
   KRAUTTER, J
   STARRFIELD, S
TI DETECTION OF SUPERSOFT X-RAY-EMISSION FROM GQ-MUSCAE 9 YEARS AFTER A NOVA OUTBURST
SO NATURE
LA English
DT Article
ID large magellanic cloud; classical novae; decline; stage; rosat
AB GQ MUS (Nova Muscae 1983) was the first classical nova from which X-rays were detected during outburst1,2. Those Exosat observations were consistent with thermonuclear burning on the surface of a white dwarf emitting 10(37)-10(38) erg s-1 at (3.0-3.5) x 10(5) K or with shocked circumstellar material emitting 10(35) erg s-1 by thermal bremsstrahlung at 10(7) K. Here we report the detection by the Rosat satellite3 of GQ Mus as a very soft black-body-like source. If the observed X-ray flux is being radiated at the Eddington luminosity (10(38) erg s-1) from a one-solar-mass white dwarf, its effective temperature must be approximately 3.5 x 10(5) K. We conclude that the white dwarf is burning hydrogen-rich material near its surface. GQ Mus is, however, the only one of 26 recent novae detected in the all-sky Rosat survey; this suggests that either most novae eject all their accreted material during outburst, or GQ Mus is now burning recently accreted material. GQ Mus appears identical to the supersoft X-ray sources CAL83, CAL87 and RX J0527.8-6954 (ref. 4), lending support to the suggestion that these sources are white dwarfs accreting and burning material from a companion5.
C1 MAX PLANCK INST EXTRATERRESTR PHYS,W-8046 GARCHING,GERMANY.
   OSSERV ASTRON TORINO,I-10025 PINO TORINESE,ITALY.
   LANDESSTERNWARTE HEIDELBERG,W-6900 HEIDELBERG,GERMANY.
   ARIZONA STATE UNIV,DEPT PHYS & ASTRON,TEMPE,AZ 85287.
C3 Max Planck Society; Istituto Nazionale Astrofisica (INAF); University of Turin; Ruprecht Karls University Heidelberg; Arizona State University; Arizona State University-Tempe
RP OGELMAN, H (corresponding author), UNIV WISCONSIN,DEPT PHYS,1150 UNIV AVE,MADISON,WI 53706, USA.
NR 24
TC 84
Z9 84
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 331
EP 333
DI 10.1038/361331a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000048
DA 2026-03-10
ER

PT J
AU HILBERG, F
   AGUZZI, A
   HOWELLS, N
   WAGNER, EF
AF HILBERG, F
   AGUZZI, A
   HOWELLS, N
   WAGNER, EF
TI C-JUN IS ESSENTIAL FOR NORMAL MOUSE DEVELOPMENT AND HEPATOGENESIS
SO NATURE
LA English
DT Article
ID cell-cycle progression; fos; differentiation; expression; oncogene; mutation; defects; growth; rb
AB THE proto-oncogene c-jun is the cellular homologue of v-jun, the transforming oncogene of the avian sarcoma virus 17 (ref. 1). c-jun encodes one major component of the AP-1 transcription factor complex and is expressed in many organs during mouse development and in the adult2-4. Because of its rapid induction in cells following growth stimulation and the presence of AP-1 binding sites in the promoter regions of many genes, the c-Jun protein is thought to have important functions in cell proliferation and differentiation2,5-10. But embryonic stem (ES) cells lacking c-Jun are viable and have a normal in vitro differentiation capacity, although c-Jun appears to be important for growth of teratocarcinomas in vivo11. To define the function of c-jun better, targeted ES cells were used to generate mice lacking c-Jun. Here we report that heterozygous mutant mice appear normal, but embryos lacking c-Jun die at mid- to late-gestation and exhibit impaired hepatogenesis, altered fetal liver erythropoiesis and generalized oedema. Interestingly, c-jun-/- ES cells can participate efficiently in the development of all somatic cells in chimaeric mice except liver cells, further suggesting an essential function of c-Jun in hepatogenesis.
C1 RES INST MOLEC PATHOL,A-1030 VIENNA,AUSTRIA.
   INST NEUROPATHOL,CH-8091 ZURICH,SWITZERLAND.
C3 Vienna Biocenter (VBC); Research Institute of Molecular Pathology (IMP)
NR 22
TC 483
Z9 546
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 179
EP 181
DI 10.1038/365179a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200053
PM 8371760
DA 2026-03-10
ER

PT J
AU MORGAN, JP
   SHEARER, PM
AF MORGAN, JP
   SHEARER, PM
TI SEISMIC CONSTRAINTS ON MANTLE FLOW AND TOPOGRAPHY OF THE 660-KM DISCONTINUITY - EVIDENCE FOR WHOLE-MANTLE CONVECTION
SO NATURE
LA English
DT Article
ID large-scale structure; northwest pacific; slab penetration; plate velocity; dynamic earth; island arcs; heterogeneity; viscosity; beneath; models
AB Recent seismic models of three-dimensional mantle structure and topography on the transition-zone seismic discontinuities permit the direct evaluation of the buoyancy forces that drive large-scale mantle flow. This buoyancy distribution, coupled with radial viscosity models that are consistent with the observed geoid, predicts flow patterns with significant vertical flow through the 660-km phase boundary. The observed topography on the 660-km discontinuity acts to inhibit convection across the boundary, but is two to four times too small to prevent whole-mantle convection.
RP MORGAN, JP (corresponding author), UNIV CALIF SAN DIEGO,INST GEOPHYS & PLANETARY PHYS,LA JOLLA,CA 92093, USA.
NR 39
TC 56
Z9 58
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 506
EP 511
DI 10.1038/365506a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100043
DA 2026-03-10
ER

PT J
AU SOMMER, T
   JENTSCH, S
AF SOMMER, T
   JENTSCH, S
TI A PROTEIN TRANSLOCATION DEFECT LINKED TO UBIQUITIN CONJUGATION AT THE ENDOPLASMIC-RETICULUM
SO NATURE
LA English
DT Article
ID yeast; degradation; membrane; enzyme; encodes; gene; polypeptides; insertion; pathway; complex
AB UBIQUITIN-Conjugating enzymes function in selective proteolysis pathways and catalyse the covalent attachment of ubiquitin to proteolytic substrates1-4. Here we report the identification of an integral membrane ubiquitin-conjugating enzyme. This enzyme, UBC6, localizes to the endoplasmic reticulum (ER), with the catalytic domain facing the cytosol. ubc6 loss-of-function mutants suppress the protein translocation defect caused by a mutation in SEC61, which encodes a key component of a multisubunit protein translocation apparatus of the ER5-11. The expression of the sec61 mutant phenotype requires both the activity of UBC6 and its localization at the ER membrane. This suggests that UBC6 may mediate selective degradation of ER membrane proteins and that the protein translocation defect of sec61 may be caused by proteolysis of components of a structurally distorted mutant translocation apparatus.
C1 MAX PLANCK GESELL,FRIEDRICH MIESCHER LAB,D-72076 TUBINGEN,GERMANY.
C3 Max Planck Society; Eberhard Karls University of Tubingen
NR 30
TC 282
Z9 322
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 176
EP 179
DI 10.1038/365176a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200052
PM 8396728
DA 2026-03-10
ER

PT J
AU HOLZENBURG, A
   BEWLEY, MC
   WILSON, FH
   NICHOLSON, WV
   FORD, RC
AF HOLZENBURG, A
   BEWLEY, MC
   WILSON, FH
   NICHOLSON, WV
   FORD, RC
TI 3-DIMENSIONAL STRUCTURE OF PHOTOSYSTEM-II
SO NATURE
LA English
DT Article
ID two-dimensional crystals; oxygen evolution; electron-microscopy; polyacrylamide gels; higher-plants; proteins; complex
AB THE photosynthetic oxidation of water occurs within a multiprotein complex called photosystem II (PSII), located in the thylakoid membranes of plants and cyanobacteria. Little information on PSII architecture is available; even the oligomeric nature of the complex is contentious, with various predictions of monomeric1, dimeric and tetrameric2-4 forms. Biochemistry suggests that it consists of an outer shell of easily removable light-harvesting proteins and a more resistant core5. The core itself can be split into further light-harvesting proteins and a reaction centre5,6. The reaction centre polypeptides bind the electron transfer components, and probably contain amino-acid residues liganded to the cluster of four Mn atoms that is believed to constitute the water 'splitting' site6-8. We report here the first, to our knowledge, three-dimensional functionally intact structure of PSII higher plants, complete with antennae and core light-harvesting proteins. Our model has been obtained by digital image processing of ordered two-dimensional arrays of the complex, such as have often been observed4,9-12.
C1 UNIV LEEDS,DEPT GENET,LEEDS LS2 9JT,W YORKSHIRE,ENGLAND.
   UNIV MANCHESTER,INST SCI & TECHNOL,DEPT BIOCHEM & APPL MOLEC BIOL,MANCHESTER M60 1QD,LANCS,ENGLAND.
C3 University of Leeds; University of Manchester
RP HOLZENBURG, A (corresponding author), UNIV LEEDS,DEPT BIOCHEM & MOLEC BIOL,LEEDS LS2 9JT,W YORKSHIRE,ENGLAND.
NR 22
TC 94
Z9 100
U1 0
U2 20
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 470
EP 472
DI 10.1038/363470a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800065
DA 2026-03-10
ER

PT J
AU BAUGHMAN, RH
   GALVAO, DS
AF BAUGHMAN, RH
   GALVAO, DS
TI CRYSTALLINE NETWORKS WITH UNUSUAL PREDICTED MECHANICAL AND THERMAL-PROPERTIES
SO NATURE
LA English
DT Article
ID negative poissons ratio; hydrocarbons; polymers; systems; carbon
AB MOST materials shrink laterally and become less dense when stretched. Materials that both expand laterally (that is, have negative Poisson's ratio) and densify when stretched are of interest both from the fundamental and the practical points of view1-5. A few monocrystalline phases with negative Poisson's ratio are known3,4, but these do not densify when stretched. Here we present molecular-mechanics calculations for some hypothetical phases of carbon which exhibit both kinds of behaviour. The properties derive from the presence of bonds that act as hinges in extended helical chains. Other unusual properties of these phases include negative thermal expansion, dopant-controlled porosity and low-temperature polymorphism. Such structures can be envisaged for polyacetylene, polydiacetylene, polyphenylene and (BN)x phases, as well as for variants of some known, structurally related inorganic phases.
C1 UNICAMP,INST FIS,BR-13081 CAMPINAS,SP,BRAZIL.
C3 Universidade Estadual de Campinas
RP BAUGHMAN, RH (corresponding author), ALLIEDSIGNAL INC,RES & TECHNOL,MORRISTOWN,NJ 07962, USA.
NR 21
TC 221
Z9 233
U1 0
U2 64
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 735
EP 737
DI 10.1038/365735a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200056
DA 2026-03-10
ER

PT J
AU LANDWEBER, LF
   GILBERT, W
AF LANDWEBER, LF
   GILBERT, W
TI RNA EDITING AS A SOURCE OF GENETIC-VARIATION
SO NATURE
LA English
DT Article
ID polymerase chain-reaction; oxidase subunit-iii; single-stranded-dna; trypanosoma-brucei; maxicircle dna; nucleotide-sequence; nadh dehydrogenase
AB KINETOPLASTID RNA editing alters mitochondrial RNA transcripts by addition and deletion of uridine residues1, producing open reading frames that may be twice as long as the original RNA2. Although the COIII gene encoding cytochrome c oxidase subunit III in Trypanosoma brucei is edited along its entire length2, the presumably homologous genes in two related trypanosomes, Leishmania tarentolae and Crithidia fasciculata, are only modestly edited at their 5' ends1. We used a comparative approach to investigate the evolution of an edited gene and to determine how well editing creates conserved protein sequences. As RNA editing probably involves the pairing of several guide RNA molecules with the messenger RNA3,4, We expected the edited proteins to be resistant to evolutionary change. Here we report that RNA editing is extensive in the mitochondria of four species of the insect parasite Herpetomonas, which is possibly an evolutionary precursor of T. brucei and L. tarentolae5, and the discovery that RNA editing is a novel source ot frameshift mutations over evolutionary time. The edited proteins accumulate mutations nearly twice as rapidly as the unedited versions.
RP LANDWEBER, LF (corresponding author), HARVARD UNIV,BIOL LABS,DEPT CELLULAR & DEV BIOL,16 DIVIN AVE,CAMBRIDGE,MA 02138, USA.
NR 16
TC 52
Z9 56
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 179
EP 182
DI 10.1038/363179a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100053
PM 8387160
DA 2026-03-10
ER

PT J
AU ZHOU, XL
   SASAKI, H
   LOWE, L
   HOGAN, BLM
   KUEHN, MR
AF ZHOU, XL
   SASAKI, H
   LOWE, L
   HOGAN, BLM
   KUEHN, MR
TI NODAL IS A NOVEL TGF-BETA-LIKE GENE EXPRESSED IN THE MOUSE NODE DURING GASTRULATION
SO NATURE
LA English
DT Article
ID cpg islands; fate
AB DURING gastrulation, the three germ layers of the embryo are formed and organized along the anterior-posterior body axis. In the mouse, gastrulation involves the delamination of ectodermal cells through the primitive streak and their differentiation into mesoderm1. These processes do not occur in embryos homozygous for a retrovirally induced recessive prenatal lethal mutation, the strain 413-d insertional mutation2,3. Instead of giving rise to mesoderm, embryonic ectoderm in 413-d mutants overproliferates and then rapidly degenerates, although extraembryonic lineages remain viable2. Here we isolate a candidate for the mutated gene which encodes a new member of the transforming growth factor-beta (TGF-beta) superfamily4 . Expression is first detected in primitive streak-stage embryos at about the time of mesoderm formation. It then becomes highly localized in the node at the anterior of the primitive streak. This region is analogous to chick Hensen's node and Xenopus dorsal lip (Spemann's organizer), which can induce secondary body axes when grafted into host embryos (reviewed in refs 5 and 6). Our findings suggest that this gene, named nodal, encodes a signalling molecule essential for mesoderm formation and subsequent organization of axial structures in early mouse development.
C1 NCI,EXPTL IMMUNOL BRANCH,BETHESDA,MD 20892.
   VANDERBILT UNIV,MED CTR,SCH MED,DEPT CELL BIOL,NASHVILLE,TN 37232.
C3 National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI); Vanderbilt University
NR 22
TC 545
Z9 684
U1 0
U2 26
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 543
EP 547
DI 10.1038/361543a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400063
PM 8429908
DA 2026-03-10
ER

PT J
AU MCDERMOTT, F
   GRUN, R
   STRINGER, CB
   HAWKESWORTH, CJ
AF MCDERMOTT, F
   GRUN, R
   STRINGER, CB
   HAWKESWORTH, CJ
TI MASS-SPECTROMETRIC U-SERIES DATES FOR ISRAELI NEANDERTHAL EARLY-MODERN HOMINID SITES
SO NATURE
LA English
DT Article
ID burial site; tabun cave; esr dates; kebara; qafzeh; time
AB THE nature of the relationship between Neanderthals and early modern Homo sapiens is controversial, yet it is fundamental to our understanding of early human evolution1,2. The Middle Palaeolithic sites of Israel are critical to this debate, because unlike those of western Europe and Africa they contain both Neanderthal (at Tabun3 and Kebara4 for example) and anatomically modern hominids (as at Skhul5 and Qafzeh6). Here we present new mass spectrometric Th-230/U-234 dates for dental fragments from the Middle Palaeolithic burial sites of Tabun, Qafzeh and Skhul. These data, combined with published ages from electron spin resonance (ESR), provide compelling evidence that the Tabun Neanderthals and Qafzeh early modern Homo sapiens were approximately coeval in the southern Levant some 100 +/- 5 kyr ago, but indicate that some of the Skhul material is younger. The study also shows that combined mass-spectrometric Th-230/U-234 and ESR dating is an invaluable technique for dating archaeological sites beyond the range of radiocarbon dating.
C1 OPEN UNIV, DEPT EARTH SCI, MILTON KEYNES MK7 6AA, BUCKS, ENGLAND.
   AUSTRALIA NATL UNIV, QUATERNARY DATING RES CTR, CANBERRA 2601, AUSTRALIA.
   NAT HIST MUSEUM, DEPT PALAEONTOL, LONDON SW7 5BD, ENGLAND.
C3 Open University - UK; Australian National University; Natural History Museum London
NR 31
TC 120
Z9 134
U1 0
U2 21
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 252
EP 255
DI 10.1038/363252a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600049
PM 8387643
DA 2026-03-10
ER

PT J
AU KULKARNI, SR
   FRAIL, DA
AF KULKARNI, SR
   FRAIL, DA
TI IDENTIFICATION OF A SUPERNOVA REMNANT COINCIDENT WITH THE SOFT GAMMA-RAY REPEATER SGR1806-20
SO NATURE
LA English
DT Article
ID high-energy transient; bursts; pulsars
AB THE 'soft' spectra, short duration and recurrent activity of the three known soft gamma-ray repeaters (SGRs) distinguishes them from the majority of cosmic gamma-ray bursts1-4. Although there is no generally accepted model for the repeaters, it has been argued5 that they are associated with radio pulsars: this is consistent with the coincidence6 of SGR0526 - 66 with the supernova remnant N49 in the Large Magellanic Cloud, and the location of the two other repeaters at low galactic latitudes. Here we show that the well localized repeater SGR1806 - 20 (refs 2, 3) is also coincident with a supernova remnant: the amorphous radio nebula G10.0 - 0.3 (refs 7, 8). Taken together, these two associations argue strongly in favour of a neutron-star origin for the repeaters. We suggest that all young pulsars-that is, neutron stars still embedded in their supernova remnants-pass through a brief (approximately 500 year) phase of SGR activity. The detection of pulsar-powered synchrotron nebulae in, or pulsations from, the two supernova remnants coincident with SGRs would confirm this model.
C1 NATL RADIO ASTRON OBSERV,SOCORRO,NM 87801.
C3 National Radio Astronomy Observatory (NRAO)
RP KULKARNI, SR (corresponding author), INST SPACE & ASTRONAUT SCI,3-1-1 YOSHINODAI,SAGAMIHARA,KANAGAWA 229,JAPAN.
NR 24
TC 131
Z9 135
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 33
EP 35
DI 10.1038/365033a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600044
DA 2026-03-10
ER

PT J
AU PAVELIN, PE
   DAVIS, RJ
   MORRISON, LV
   BODE, MF
   IVISON, RJ
AF PAVELIN, PE
   DAVIS, RJ
   MORRISON, LV
   BODE, MF
   IVISON, RJ
TI RADIO OBSERVATIONS OF THE CLASSICAL NOVA-CYGNI-92 80 DAYS AFTER OUTBURST
SO NATURE
LA English
DT Article
ID scale
AB CATACLYSMIC variables are interacting binary stellar systems containing a main-sequence secondary component and a collapsed primary component, usually a white dwarf. A subset of these systems give rise to classical novae, in which an explosive outburst caused by 'runaway' thermonuclear processes on the surface of the white dwarf produces a large increase in visual magnitude and the ejection of substantial quantities of stellar material1. Radio emission has been detected from several classical novae17, and is attributed to the thermal bremsstrahlung mechanism operating within an isothermal, expanding shell of ionized gas. Such observations offer a means of directly probing the shells during the early stages of their evolution - long before they can be resolved by optical telescopes. Here we report radio observations of one of the brightest novae in recent years, Nova Cygni 92, using the MERLIN radiotelescope array. The structure of the shell is first resolved eighty days after the initial outburst, revealing nonspherical expansion and thermal electron temperatures that rapidly exceed the expected value for a radiatively excited hydrogen plasma. We explain the observed temperatures by means of a model in which the gas is heated in shocks produced by the thermonuclear runaway.
C1 ROYAL GREENWICH OBSERV,CAMBRIDGE CB3 0EZ,ENGLAND.
   LIVERPOOL JOHN MOORES UNIV,DEPT CHEM & PHYS SCI,LIVERPOOL L3 3AF,ENGLAND.
   UNIV TORONTO,DEPT ASTRON,TORONTO M5S 1A7,ONTARIO,CANADA.
C3 University of Cambridge; Liverpool John Moores University; University of Toronto
RP PAVELIN, PE (corresponding author), UNIV MANCHESTER,NUFFIELD RADIO ASTRON LABS,JODRELL BANK,MACCLESFIELD SK11 9DL,CHESHIRE,ENGLAND.
NR 17
TC 24
Z9 25
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 424
EP 426
DI 10.1038/363424a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800049
DA 2026-03-10
ER

PT J
AU PARKER, LL
   WALTER, SA
   YOUNG, PG
   PIWNICAWORMS, H
AF PARKER, LL
   WALTER, SA
   YOUNG, PG
   PIWNICAWORMS, H
TI PHOSPHORYLATION AND INACTIVATION OF THE MITOTIC INHIBITOR WEE1 BY THE NIM1/CDR1 KINASE
SO NATURE
LA English
DT Article
ID tyrosine phosphatase; activates p34cdc2; cdc25 protein; dephosphorylation; inducer; fission
AB THE G2-M phase transition in eukaryotes is regulated by the synergistic and opposing activities of a cascade of distinct protein kinases and phosphatases. This cascade converges on Cdc2, a serine/threonine protein kinase required for entry into mitosis (reviewed in ref. 1). In the fission yeast Schizosacckaromyces pombe, inactivation of the Cdc2/cyclin B complex is achieved by phosphorylation of tyrosine 15 by Wee1 (refs 2, 3). The action of the Wee1 kinase is opposed by the action of the Cdc25 phosphatase, which dephosphorylates Cdc2 on tyrosine 15, thereby activating the Cdc2/cyclin B complex4-9. Much less is known about the regulatory signals upstream of cdc25 and wee1. Genetics indicate that the mitotic inducer nim1/cdr1 acts upstream of wee1, possibly as a negative regulator of wee1 (refs 10, 11). To characterize the nim1/cdr1 protein (Nim1), we have overproduced it in both bacterial and baculoviral expression systems. We report that Nim1 possesses intrinsic serine-kinase, threonine-kinase and tyrosine-kinase activities. Co-expression of the Nim1 and Wee1 kinases in insect cells results in the phosphorylation of Wee1 and therefore a shift in its electrophoretic mobility on SDS-polyacrylamide gels. When Weel is phosphorylated, its ability to phosphorylate Cdc2 on tyrosine 15 is inhibited; treatment with phosphatase restores this kinase activity. Furthermore, purified bacterially produced Nim1 kinase directly phosphorylates and inactivates Weel in vitro. These results show that nim1/cdr1 functions as a positive regulator of mitosis by directly phosphorylating and inactivating the mitotic inhibitor Wee1.
C1 HARVARD UNIV,SCH MED,DEPT MICROBIOL & MOLEC GENET,BOSTON,MA 02115.
   QUEENS UNIV,DEPT BIOL,KINGSTON K7L 3N6,ONTARIO,CANADA.
C3 Harvard University; Harvard Medical School; Queens University - Canada
RP PARKER, LL (corresponding author), BETH ISRAEL HOSP,BLDG D2,ROOM 143,200 LONGWOOD AVE,BOSTON,MA 02215, USA.
NR 14
TC 138
Z9 164
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 736
EP 738
DI 10.1038/363736a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900060
PM 8515817
DA 2026-03-10
ER

PT J
AU BACKER, DC
   FOSTER, RS
   SALLMEN, S
AF BACKER, DC
   FOSTER, RS
   SALLMEN, S
TI A 2ND COMPANION OF THE MILLISECOND PULSAR-1620-26
SO NATURE
LA English
DT Article
AB MILLISECOND pulsars are usually found in binary systems. This is in keeping with the generally accepted model for the formation of such pulsars14 in which an old neutron star is spun up to high angular velocities by the accretion of matter from a companion star. The millisecond pulsar 1620-26 in the globular cluster M4 is no exception: timing measurements1,2 reveal the presence of a 0.3-solar-mass companion star (probably a white dwarf) with an orbital period of 191 days. But subsequent measurements of this pulsar have identified a small but significant deviation from the expected behaviour3,4, suggestive of an unusually large second derivative in the pulsar's rotation rate5. Here we examine several possible sources-both intrinsic and extrinsic-for this derivative, and we find that it is best explained by the presence of a second, weakly bound companion object moving in a wide orbit around the main binary system. The third body in this hierarchical system has an orbital period of approximately 100 years and a mass approximately ten times that of Jupiter, and may have been captured during a recent collision with another stellar system6.
C1 USN,RES LAB,DIV REMOTE SENSING,WASHINGTON,DC 20375.
C3 United States Department of Defense; United States Navy; United States Naval Research Laboratory; NRL Chesapeake
RP BACKER, DC (corresponding author), UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720, USA.
NR 16
TC 86
Z9 96
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 817
EP 819
DI 10.1038/365817a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100042
DA 2026-03-10
ER

PT J
AU PIPER, KR
   VONBODMAN, SB
   FARRAND, SK
AF PIPER, KR
   VONBODMAN, SB
   FARRAND, SK
TI CONJUGATION FACTOR OF AGROBACTERIUM-TUMEFACIENS REGULATES TI-PLASMID TRANSFER BY AUTOINDUCTION
SO NATURE
LA English
DT Article
ID crown gall tumors; genetic-analysis; expression; nopaline; ptic58; bioluminescence; sequence; fischeri; cloning; locus
AB CONJUGAL transfer of Ti plasmids from Agrobacterium donors to bacterial recipients is controlled by two types of diffusible signal molecules. Induction is mediated by novel compounds, called opines, that are secreted by crown gall tumours. These neoplasias result from infection of susceptible plants by virulent agrobacteria. The second diffusible signal, called conjugation factor, is synthesized by the donor bacteria themselves. Production of this factor is induced by the opine. Here we show that conjugation is regulated directly by a transcriptional activator, TraR, which requires conjugation factor as a coinducer to activate tra gene expression. TraR is a homologue of LuxR, the lux gene activator from Vibrio fischeri which also requires an endogenously synthesized diffusible coinducer. The two regulatory systems are related; the two activator proteins show amino-acid sequence similarities and the lux system cofactor, autoinducer, will substitute for conjugation factor in the TraR-dependent activation of Ti plasmid tra genes.
C1 UNIV ILLINOIS, DEPT PLANT PATHOL, URBANA, IL 61801 USA.
   UNIV ILLINOIS, DEPT MICROBIOL, URBANA, IL 61801 USA.
C3 University of Illinois System; University of Illinois Urbana-Champaign; University of Illinois System; University of Illinois Urbana-Champaign
NR 24
TC 426
Z9 497
U1 0
U2 53
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 448
EP 450
DI 10.1038/362448a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400083
PM 8464476
DA 2026-03-10
ER

PT J
AU PONMAN, TJ
   BERTRAM, D
AF PONMAN, TJ
   BERTRAM, D
TI HOT GAS AND DARK MATTER IN A COMPACT GALAXY GROUP
SO NATURE
LA English
DT Article
ID x-ray; elliptical galaxy; clusters; einstein
AB COMPACT groups of galaxies have such high apparent densities that their members are separated in projection by only a few galactic radii, making them the most promising environment in the low-redshift Universe for studying the effects of galaxy merging. But the dynamical and evolutionary status of these groups is still subject to considerable uncertainty1-3, partly because of the bias introduced by the selection criteria used to identify them4. Using the Rosat X-ray telescope5, we have detected a large cloud of hot gas centred on the compact group HCG62. From the properties of this gas, rather than the galaxies themselves, we are able to infer both the distribution of dark matter (which extends significantly beyond the apparent optical confines of the group and dominates its total mass) and the evolution of the group as a whole. The compact core of galaxies seems to have formed as a result of orbital decay in a much more extended system, and should culminate in a final merger within a few billion years. We suggest that a new class of 'fossil' groups, consisting of a large elliptical galaxy embedded at the centre of an extended X-ray halo, awaits discovery by Rosat.
RP PONMAN, TJ (corresponding author), UNIV BIRMINGHAM, SCH PHYS & SPACE RES, BIRMINGHAM B15 2TT, W MIDLANDS, ENGLAND.
NR 26
TC 148
Z9 151
U1 0
U2 0
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 51
EP 54
DI 10.1038/363051a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200052
DA 2026-03-10
ER

PT J
AU VONGUNTEN, HR
   LIENERT, C
AF VONGUNTEN, HR
   LIENERT, C
TI DECREASED METAL CONCENTRATIONS IN GROUND-WATER CAUSED BY CONTROLS OF PHOSPHATE EMISSIONS
SO NATURE
LA English
DT Article
ID river water; infiltration; switzerland
AB A NEW generation of phosphate-eliminating sewage treatment plants and the recent prohibition of phosphates in detergents have considerably reduced the concentrations of phosphate in surface waters1. But there has been concern that replacing phosphate in detergents with complexing agents might cause increased mobilization of heavy metals, and corsequent pollution of ground waters2,3. Here we present a twelve-year analysis of phosphate, manganese and cadmium in the river Glatt, Switzerland, and in an adjacent aquifer which is infiltrated by the river water. Together with a reduction of phosphate concentrations in both river and ground water over the study period, we find lower groundwater concentrations of manganese and cadmium. We postulate that lower phosphate levels have decreased the amount of oxidizable organic carbon in the river bed, and hence have created less reducing conditions in the infiltrating water. This in turn has resulted in decreased reductive dissolution of manganese and cadmium in the ground water. It thus appears that eliminating phosphate has led to an unexpected improvement in drinking water quality with respect to heavy metals.
C1 PAUL SCHERRER INST,CH-5232 VILLIGEN PSI,SWITZERLAND.
C3 Swiss Federal Institutes of Technology Domain; Paul Scherrer Institute
RP VONGUNTEN, HR (corresponding author), UNIV BERN,RADIOCHEM LAB,CH-3000 BERN 9,SWITZERLAND.
NR 21
TC 21
Z9 23
U1 0
U2 27
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 220
EP 222
DI 10.1038/364220a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300051
DA 2026-03-10
ER

PT J
AU LASKAR, J
   JOUTEL, F
   ROBUTEL, P
AF LASKAR, J
   JOUTEL, F
   ROBUTEL, P
TI STABILIZATION OF THE EARTHS OBLIQUITY BY THE MOON
SO NATURE
LA English
DT Article
ID rotation
AB ACCORDING to Milankovitch theory1,2, the ice ages are related to variations of insolation in northern latitudes resulting from changes in the Earth's orbital and orientation parameters (precession, eccentricity and obliquity). Here we investigate the stability of the Earth's orientation for all possible values of the initial obliquity, by integrating the equations of precession of the Earth. We find a large chaotic zone which extends from 60-degrees to 90-degrees in obliquity. In its present state, the Earth avoids this chaotic zone and its obliquity is essentially stable, exhibiting only small variations of +/- 1.3-degrees around the mean value of 23.3-degrees. But if the Moon were not present, the torque exerted on the Earth would be smaller, and the chaotic zone would then extend from nearly 0-degrees up to about 85-degrees. Thus, had the planet not acquired the Moon, large variations in obliquity resulting from its chaotic behaviour might have driven dramatic changes in climate. In this sense one might consider the Moon to act as a potential climate regulator for the Earth.
RP LASKAR, J (corresponding author), BUR LONGITUDES,77 AVE DENFERT ROCHEREAU,F-75014 PARIS,FRANCE.
NR 14
TC 246
Z9 275
U1 0
U2 44
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 615
EP 617
DI 10.1038/361615a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600056
DA 2026-03-10
ER

PT J
AU LEWIS, MA
   MURRAY, JD
AF LEWIS, MA
   MURRAY, JD
TI MODELING TERRITORIALITY AND WOLF DEER INTERACTIONS
SO NATURE
LA English
DT Article
AB WE propose here a mechanism for territorial pattern formation in wolves (Canis lupus) and analyse it using a spatially explicit mathematical model incorporating wolf movement and scent marking. Model results reflect field observations from northeastern Minnesota: buffer zones where wolves are scarce arise between adjacent packs, and near these buffer zones there are increased levels of scent marking1,2. Territories are arranged in a spatial mosaic (Fig. 1) which covers the wolf range. In the model formulation no assumptions are made about actual existence or extent of wolf territory and buffer zones; these arise naturally as stable steady-state solutions to the equations. We show mathematically how reduced predation by wolves in the buffer zones provides a refuge for prey species. Field studies support this; distribution of a primary prey species, white-tailed deer (Odocoileus virginianus), correlates negatively with that of wolves. Deer are found primarily in buffer zones3,4 (Fig. 2).
C1 UNIV WASHINGTON,DEPT APPL MATH,SEATTLE,WA 98195.
C3 University of Washington; University of Washington Seattle
RP LEWIS, MA (corresponding author), UNIV UTAH,DEPT MATH,JWB 233,SALT LAKE CITY,UT 84112, USA.
NR 11
TC 163
Z9 194
U1 0
U2 61
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 23
PY 1993
VL 366
IS 6457
BP 738
EP 740
DI 10.1038/366738a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MN264
UT WOS:A1993MN26400026
DA 2026-03-10
ER

PT J
AU ZHONG, W
   CAI, Y
   TOMANEK, D
AF ZHONG, W
   CAI, Y
   TOMANEK, D
TI COMPUTER-SIMULATION OF HYDROGEN EMBRITTLEMENT IN METALS
SO NATURE
LA English
DT Article
ID embedded-atom-method; molecular-dynamics; assisted cracking; abinitio calculation; pd(001); equilibrium; palladium; pd(110); model
AB IT has been long known that hydrogen can substantially reduce the mechanical stability of transition metals under tensile stress1-3. This phenomenon of 'hydrogen embrittlement' has important consequences for the safety of fusion reactors and for space technology; but there remains considerable uncertainty about its microscopic origin2,3. Here we report the results of a study of fracture of hydrogen-loaded palladium under tensile stress which uses Parrinello-Rahman molecular dynamics based on a many-body alloy hamiltonian. A rather unexpected result is that the apparent hydrogen embrittlement results from a local enhancement of ductility in hydrogen-saturated regions of the metal which causes a reduction of the critical tensile stress at which failure occurs.
C1 MICHIGAN STATE UNIV,CTR FUNDAMENTAL MAT RES,E LANSING,MI 48824.
C3 Michigan State University
RP ZHONG, W (corresponding author), MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824, USA.
NR 27
TC 53
Z9 57
U1 3
U2 47
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 435
EP 437
DI 10.1038/362435a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400078
DA 2026-03-10
ER

PT J
AU BOND, G
   BROECKER, W
   JOHNSEN, S
   MCMANUS, J
   LABEYRIE, L
   JOUZEL, J
   BONANI, G
AF BOND, G
   BROECKER, W
   JOHNSEN, S
   MCMANUS, J
   LABEYRIE, L
   JOUZEL, J
   BONANI, G
TI CORRELATIONS BETWEEN CLIMATE RECORDS FROM NORTH-ATLANTIC SEDIMENTS AND GREENLAND ICE
SO NATURE
LA English
DT Article
ID last deglaciation; ocean
AB OXYGEN isotope measurements in Greenland ice demonstrate that a series of rapid warm-cold oscillations-called Dansgaard-Oeschger events-punctuated the last glaciation1. Here we present records of sea surface temperature from North Atlantic sediments spanning the past 90 kyr which contain a series of rapid temperature oscillations closely matching those in the ice-core record, confirming predictions that the ocean must bear the imprint of the Dansgaard-Oeschger events2,3. Moreover, we show that between 20 and 80 kyr ago, the shifts in ocean-atmosphere temperature are bundled into cooling cycles, lasting on average 10 to 15 kyr, with asymmetrical saw-tooth shapes. Each cycle culminated in an enormous discharge of icebergs into the North Atlantic (a 'Heinrich event'4,5), followed by an abrupt shift to a warmer climate. These cycles document a previously unrecognized link between ice sheet behaviour and ocean-atmosphere temperature changes. An important question that remains to be resolved is whether the cycles are driven by external factors, such as orbital forcing, or by internal ice-sheet dynamics.
C1 UNIV COPENHAGEN,NIEHLS BOHR INST,DEPT GEOPHYS,DK-2200 COPENHAGEN,DENMARK.
   UNIV ICELAND,INST SCI,DEPT GEOPHYS,IS-107 REYKJAVIK,ICELAND.
   CFR,CEA,CNRS,MIXTE LAB,F-91198 GIF SUR YVETTE,FRANCE.
   CTR ETUD SACLAY,DSM,CEA,MODELISAT CLIMAT & ENVIRONNEMENT LAB,F-91191 GIF SUR YVETTE,FRANCE.
   CNRS,GLACIOL & GEOPHYS ENVIRONNEMENT LAB,F-38402 ST MARTIN DHERES,FRANCE.
   SWISS FED INST TECHNOL,INST MITTELENERGIEPHYS,CH-8093 ZURICH,SWITZERLAND.
C3 University of Copenhagen; University of Iceland; Centre National de la Recherche Scientifique (CNRS); Universite Paris Saclay; CEA; CEA; Universite Paris Saclay; Centre National de la Recherche Scientifique (CNRS); Swiss Federal Institutes of Technology Domain; ETH Zurich
RP BOND, G (corresponding author), COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964, USA.
NR 27
TC 1823
Z9 2101
U1 7
U2 530
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 143
EP 147
DI 10.1038/365143a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200043
DA 2026-03-10
ER

PT J
AU DEMUIZON, C
AF DEMUIZON, C
TI WALRUS-LIKE FEEDING ADAPTATION IN A NEW CETACEAN FROM THE PLIOCENE OF PERU
SO NATURE
LA English
DT Article
AB THE recent discovery in the Southern Hemisphere (15.5-degrees-S) of a walrus-like skull of a toothed whale (odontocete) from the Pisco Formation of southern Peru presents a startling example of convergence and specialization unprecedented among cetaceans. In contrast to other toothed whales, Odobenocetops peruvianus has no elongated rostrum but has large, ventrally directed premaxillary alveolar processes housing asymmetrical tusks. The dorsally facing orbits indicate the possibility of dorsal binocular vision which could compensate for the absence of the melon, a rostral organ involved in echolocation. Strong muscle scars on the anterior edge of the premaxillae suggest the presence of a powerful upper lip. It is this feature, together with the morphology of the deep vaulted palate devoid of maxillary teeth, that enables us to hypothesize a convergent feeding adaptation with the walrus which feeds mainly on thin-shelled bivalve molluscs, sucking out the foot and/or siphon and ejecting the shell. The structure of the face and basicranium indicates it was a delphinoid cetacean, probably related to the living beluga and narwhal (Monodontidae).
RP DEMUIZON, C (corresponding author), INST FRANCAIS ETUD ANDINES,CNRS,URA 12,CASILLA 18-1217,LIMA 18,PERU.
NR 30
TC 44
Z9 47
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 745
EP 748
DI 10.1038/365745a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200060
DA 2026-03-10
ER

PT J
AU WATERS, JW
   FROIDEVAUX, L
   READ, WG
   MANNEY, GL
   ELSON, LS
   FLOWER, DA
   JARNOT, RF
   HARWOOD, RS
AF WATERS, JW
   FROIDEVAUX, L
   READ, WG
   MANNEY, GL
   ELSON, LS
   FLOWER, DA
   JARNOT, RF
   HARWOOD, RS
TI STRATOSPHERIC CIO AND OZONE FROM THE MICROWAVE LIMB SOUNDER ON THE UPPER-ATMOSPHERE RESEARCH SATELLITE
SO NATURE
LA English
DT Article
ID high-altitude aircraft; insitu er-2 data; antarctic ozone; polar vortex; arctic stratosphere; potential vorticity; hydrogen-chloride; nitric-acid; destruction; denitrification
AB Concentrations of atmospheric ozone and of CIO (the predominant form of reactive chlorine responsible for stratospheric ozone depletion) are reported for both the Arctic and Antarctic winters of the past 18 months. Chlorine in the lower stratosphere was almost completely converted to chemically reactive forms in both the northern and southern polar winter vortices. This occurred in the south long before the development of the Antarctic ozone hole, suggesting that ozone loss can be masked by influx of ozone-rich air.
C1 UNIV EDINBURGH,DEPT METEOROL,EDINBURGH EH9 3JZ,MIDLOTHIAN,SCOTLAND.
C3 University of Edinburgh
RP WATERS, JW (corresponding author), JET PROP LAB,PASADENA,CA 91109, USA.
NR 52
TC 244
Z9 249
U1 0
U2 18
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 597
EP 602
DI 10.1038/362597a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800036
DA 2026-03-10
ER

PT J
AU PFLUGL, G
   KALLEN, J
   SCHIRMER, T
   JANSONIUS, JN
   ZURINI, MGM
   WALKINSHAW, MD
AF PFLUGL, G
   KALLEN, J
   SCHIRMER, T
   JANSONIUS, JN
   ZURINI, MGM
   WALKINSHAW, MD
TI X-RAY STRUCTURE OF A DECAMERIC CYCLOPHILIN CYCLOSPORINE CRYSTAL COMPLEX
SO NATURE
LA English
DT Article
ID binding; protein; isomerase
AB HUMAN cyclophilin A (CypA), a ubiquitous intracellular protein of 165 amino acids, is the major receptor for the cyclic undecapeptide immunosuppressant drug cyclosporin A (CsA)1,2, which pre vents allograft rejection after transplant surgery3,4 and is efficacious in the field of autoimmune diseases5. CsA prevents T-cell proliferation by blocking the calcium-activated pathway leading to interleukin-2 transcription. Besides their ability to bind CsA, the cyclophilin isoforms6-8 also have peptidyl-prolyl isomerase activity9-11 and enhance the rate of protein folding12,13. The macrolide FK506 acts similarly to CsA and its cognate receptor FKBP also has peptidyl-prolyl isomerase activity14. Inhibition of this enzymatic activity alone is not sufficient to achieve immunosuppression15,16. A direct molecular interaction between the drug-immunophilin complex (CsA-CypA, or FK506-FKBP) and the phosphatase calcineurin, is responsible for modulating the T-cell receptor signal transduction pathway17,18. Here we describe the crystal structure of a decameric CypA-CsA complex. The crystallographic asymmetric unit is composed of a pentamer of 1 : 1 cyclophilin-cyclosporin complexes of rather exact non-crystallographic fivefold symmetry. The 2.8 angstrom electron density map is of high quality. The five independent cyclosporin molecules are clearly identifiable, providing an unambiguous picture of the detailed interactions between a peptide drug and its receptor. It broadly confirms the results of previous NMR, X-ray and modelling studies, but provides further important structural details which will be of use in the design of drugs that are analogues of CsA.
C1 SANDOZ PHARMA AG,PRECLIN RES,CH-4002 BASEL,SWITZERLAND.
   UNIV BASEL,BIOCTR,CH-4056 BASEL,SWITZERLAND.
C3 Novartis; Sandoz; University of Basel
NR 33
TC 197
Z9 213
U1 1
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 91
EP 94
DI 10.1038/361091a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800057
PM 8421501
DA 2026-03-10
ER

PT J
AU VANMEGEN, W
   UNDERWOOD, SM
AF VANMEGEN, W
   UNDERWOOD, SM
TI CHANGE IN CRYSTALLIZATION MECHANISM AT THE GLASS-TRANSITION OF COLLOIDAL SPHERES
SO NATURE
LA English
DT Article
ID suspensions
AB THE crystallization of 'hard' spheres, which interact only through repulsive forces on contact, is a purely entropic effect and provides a motel system for testing theories of freezing transitions in liquids generally1. Micrometre-sized colloidal particles can be made to approximate hard spheres by grafting of polymers to their surfaces1. Their slow dynamics make them attractive systems for the stud of crystallization kinetics2-4. As well as undergoing crystallization1,2, such particles also exhibit a glass transition at a well-defined volume fraction phi(g), which we have shown previously to be related to the cessation of large-scale diffusion on experimental timescales5,6. Here we show that the glass transition coincides with a change in the mechanism of crystallization. At volume fractions less than phi(g) isometric crystals are nucleated homogeneously throughout the sample, whereas above phi(g) crystals forming slowly in the metastable glass phase are highly asymmetric. Regular rocking of the suspension above the glass transition induces more rapid formation of plate-like crystals, indicating that their nucleation is shear-induced.
RP VANMEGEN, W (corresponding author), ROYAL MELBOURNE INST TECHNOL,DEPT APPL PHYS,MELBOURNE,VIC 3001,AUSTRALIA.
NR 9
TC 105
Z9 119
U1 0
U2 31
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 616
EP 618
DI 10.1038/362616a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800041
DA 2026-03-10
ER

PT J
AU MCCORMICK, D
AF MCCORMICK, D
TI TAKING A CALCULATED OPPORTUNITY
SO NATURE
LA English
DT Article
NR 4
TC 0
Z9 0
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 489
EP 491
DI 10.1038/366489a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800072
DA 2026-03-10
ER

PT J
AU LARDER, BA
   KELLAM, P
   KEMP, SD
AF LARDER, BA
   KELLAM, P
   KEMP, SD
TI CONVERGENT COMBINATION THERAPY CAN SELECT VIABLE MULTIDRUG-RESISTANT HIV-1 IN-VITRO
SO NATURE
LA English
DT Article
ID human-immunodeficiency-virus; reverse-transcriptase inhibitors; high-level resistance; nonnucleoside inhibitors; zidovudine azt; type-1; sensitivity; replication; mutation; susceptibility
AB THE reverse transcriptase enzyme of human immunodeficiency virus type 1 (HIV-1) is the target for many inhibitors1. Amino-acid substitutions in functional regions of the enzyme that abolish reverse transcriptase activity also prevent HIV-1 replication2,3. But selection pressure by drugs such as AZT (3'-azido-3'-deoxythymidine, zidovudine)4-6, ddI(2',3'-dideoxyinosine)7,8 and non-nucleoside reverse transcriptase inhibitors (NNRTIs)9-14 causes outgrowth of resistant variants due to non-lethal mutations in the enzyme7,9-16. Reports of synergy17-19 and lack of cross-resistance between reverse transcriptase inhibitors (refs 7, 9, 10, 12-14, 17, 18, 20, 21), plus the reversal of AZT resistance by mutations induced by ddI7 and NNRTIs14, have indicated that specific drug combinations directed at reverse transcriptase might curtail resistance. Chow et al.22 extended this concept in a report that specific multiple combinations of resistance mutations in the reverse transcriptase can significantly impair HIV-1 replication. They concluded that evolutionary limitations may exist to prevent the emergence of multidrug resistance to inhibitors of reverse transcriptase22. We report here that HIV-1 co-resistant to AZT, ddI and the NNRTI nevirapine23 can be readily selected in cell culture starting with dual AZT- and ddI-resistant virus. We found no evidence for 'replication incompatible' combinations of resistance mutations, although a mutation (M184-->V) conferring oxathiolane-cytosine nucleoside resistance in reverse transcriptase24,25 completely suppressed AZT resistance in a triple-resistant background. These in vitro observations suggest that triple drug combination therapy might ultimately result in co-resistant HIV-1, although they do not preclude assessment of such combinations for treatment of HIV-1 disease.
RP LARDER, BA (corresponding author), WELLCOME RES LABS,ANTIVIRAL THERAPEUT RES UNIT,LANGLEY COURT,BECKENHAM BR3 3BS,KENT,ENGLAND.
NR 29
TC 145
Z9 159
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 451
EP 453
DI 10.1038/365451a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300059
PM 7692302
DA 2026-03-10
ER

PT J
AU SCHRENK, F
   BROMAGE, TG
   BETZLER, CG
   RING, U
   JUWAYEYI, YM
AF SCHRENK, F
   BROMAGE, TG
   BETZLER, CG
   RING, U
   JUWAYEYI, YM
TI OLDEST HOMO AND PLIOCENE BIOGEOGRAPHY OF THE MALAWI RIFT
SO NATURE
LA English
DT Article
AB THE Malawi Rift and Pliocene palaeofaunas, which include a hominid mandible attributed to Homo rudolfensis, provide a biogeographical link between the better known Plio-Pleistocene faunal records of East and Southern Africa. The Malawi Rift is in a latitudinal position suitable for recording any hominid and faunal dispersion towards the Equator that was brought on by increased aridity of the Late Pliocene African landscape. The evidence suggests that Pliocene hominids originated in the eastern African tropical domain and dispersed to southern Africa only during more favourable ecological circumstances.
C1 UNIV FRANKFURT,INST GEOL PALAONTOL,D-60325 FRANKFURT,GERMANY.
   UNIV MAINZ,INST GEOWISSENSCH,D-55099 MAINZ,GERMANY.
   DEPT ANTIQUITIES,LILONGWE,MALAWI.
   CUNY HUNTER COLL,DEPT ANTHROPOL,NEW YORK,NY 10021.
C3 Goethe University Frankfurt; Johannes Gutenberg University of Mainz; City University of New York (CUNY) System; Hunter College (CUNY)
RP SCHRENK, F (corresponding author), HESS LANDESMUSEUM,DEPT PALAEONTOL,FRIEDENSPL 1,D-64283 DARMSTADT,GERMANY.
NR 26
TC 116
Z9 128
U1 1
U2 17
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 833
EP 836
DI 10.1038/365833a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100048
PM 8413666
DA 2026-03-10
ER

PT J
AU RAINIER, S
   JOHNSON, LA
   DOBRY, CJ
   PING, AJ
   GRUNDY, PE
   FEINBERG, AP
AF RAINIER, S
   JOHNSON, LA
   DOBRY, CJ
   PING, AJ
   GRUNDY, PE
   FEINBERG, AP
TI RELAXATION OF IMPRINTED GENES IN HUMAN CANCER
SO NATURE
LA English
DT Article
ID wiedemann-beckwith syndrome; wilms-tumor; h19 gene; heterozygosity; chromosome-11; hypomethylation; carcinoma; disomy; 11p; rna
AB GENOMIC imprinting, or parental allele-specific expression of genes, has been demonstrated at the molecular level in insects and mice1,2 but not in man. Imprinting as a potential mechanism of human disease is suggested by paternal uniparental disomy of 11p15 in Beckwith-Wiedemann syndrome3 and by maternal uniparental disomy of 15q11-12 in Prader-Willi syndrome4. Beckwith-Wiedemann syndrome is characterized by multiorgan overgrowth and predisposition to embryonal tumours such as Wilms' tumour of the kidneys. A loss of heterozygosity of 11p15 is also frequently found in a wide variety of tumours, including Wilms' tumour and lung, bladder, ovarian, liver and breast cancers6-11; 11p15 also directly suppresses tumour growth in vitro 12 . Two genes in this band, H19 and insulin-like growth factor-11 (IGF2) undergo reciprocal imprinting in the mouse., with maternal expression of H19 (ref. 13) and paternal expression of IGF2 (ref. 14). Here we find that both of these genes show monoallelic expression in human tissues and, as in mouse, H19 is expressed from the maternal allele and IGF2 from the paternal allele. In contrast, 69% of Wilms' tumours not undergoing loss of heterozygosity at 11p showed biallelic expression of one or both genes, suggesting that relaxation or loss of imprinting could represent a new epigenetic mutational mechanism in carcinogenesis.
C1 UNIV MICHIGAN, SCH MED, HOWARD HUGHES MED INST, 4520 MSRB 1, ANN ARBOR, MI 48109 USA.
   UNIV MICHIGAN, SCH MED, DEPT INTERNAL MED, ANN ARBOR, MI 48109 USA.
   UNIV MICHIGAN, SCH MED, DEPT HUMAN GENET, ANN ARBOR, MI 48109 USA.
   CROSS CANC INST, DEPT PEDIAT, EDMONTON T6G 1Z2, ALBERTA, CANADA.
   UNIV ALBERTA, EDMONTON T6G 1Z2, AB, CANADA.
C3 University of Michigan System; University of Michigan; Howard Hughes Medical Institute; University of Michigan System; University of Michigan; University of Michigan System; University of Michigan; University of Alberta; University of Alberta
NR 39
TC 754
Z9 803
U1 0
U2 48
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 747
EP 749
DI 10.1038/362747a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000055
PM 8385745
DA 2026-03-10
ER

PT J
AU IMBRIE, J
   MIX, AC
   MARTINSON, DG
AF IMBRIE, J
   MIX, AC
   MARTINSON, DG
TI MILANKOVITCH THEORY VIEWED FROM DEVILS HOLE
SO NATURE
LA English
DT Article
ID last interglacial period; astronomical calibration; mass-spectrometry; ice ages; pleistocene
AB VARIATIONS in the oxygen isotope content (deltaO-18) of late Quaternary deep-sea sediments mainly reflect changes in continental ice mass1, and hence provide important information about the timing of past ice ages. Because these sediments cannot yet be dated directly beyond the range of radiocarbon dating (40-50 kyr), ages for the deltaO-18 record have been generated2,3 by matching the phase of the changes in deltaO-18 to that of variations in the Earth's precession and obliquity. Adopting this timescale yields a close correspondence between the time-varying amplitudes of these orbital variations and those of a wide range of climate proxies4, lending support to the Milankovitch theory that the Earth's glacial-interglacial cycles are driven by orbital variations. Recently Winograd et al.5 reported a record of deltaO-18 variations in a fresh-water carbonate sequence from Devils Hole, Nevada, dated by U-Th disequilibrium6. They concluded that the timing of several of the features in the record, which reflects changes in the temperature of precipitation over Nevada as well as changes in the isotopic composition of the moisture source5,7, showed significant deviations from that predicted by Milankovitch theory. Here we demonstrate that applying the Devils Hole chronology to ocean cores requires physically implausible changes in sedimentation rate. Moreover, spectral analysis of the Devils Hole record shows clear evidence of orbital influence. We therefore conclude that transfer of the Devils Hole chronology to the marine record is inappropriate, and that the evidence in favour of Milankovitch theory remains strong.
C1 OREGON STATE UNIV, COLL OCEANOG, CORVALLIS, OR 97331 USA.
   COLUMBIA UNIV, LAMONT DOHERTY EARTH OBSERV, PALISADES, NY 10964 USA.
C3 Oregon State University; Columbia University
RP IMBRIE, J (corresponding author), BROWN UNIV, DEPT GEOL SCI, PROVIDENCE, RI 02912 USA.
NR 39
TC 53
Z9 61
U1 0
U2 25
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 531
EP 533
DI 10.1038/363531a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900045
DA 2026-03-10
ER

PT J
AU WAUGH, DW
AF WAUGH, DW
TI SUBTROPICAL STRATOSPHERIC MIXING LINKED TO DISTURBANCES IN THE POLAR VORTICES
SO NATURE
LA English
DT Article
ID potential vorticity; breaking; vortex; ozone
AB RANDEL et al.1 have observed tongues of stratospheric air stretching from the tropics into middle latitudes, and conclude that such events may be responsible for transporting significant amounts of stratospheric air across the tropical-mid-latitude barrier2. Here I examine the movements of air parcels during these events using high-resolution contour-trajectory calculations. My calculations suggest that the tongues of tropical air are associated with disturbances of the stratospheric polar vortices. The edge of the disturbed polar vortex reaches low latitudes, and draws a long tongue of tropical air around the vortex into middle latitudes. This process occurs in the winter of both hemispheres, although the edge of the larger Antarctic polar vortex reaches farther toward the Equator, and draws up material from lower latitudes, than its Arctic counterpart.
RP WAUGH, DW (corresponding author), MIT,CTR METEOROL & PHYS OCEANOG,CAMBRIDGE,MA 02139, USA.
NR 18
TC 70
Z9 72
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 535
EP 537
DI 10.1038/365535a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100049
DA 2026-03-10
ER

PT J
AU ANDERSON, SJ
   LEVIN, SD
   PERLMUTTER, RM
AF ANDERSON, SJ
   LEVIN, SD
   PERLMUTTER, RM
TI PROTEIN-TYROSINE KINASE P56(LCK) CONTROLS ALLELIC EXCLUSION OF T-CELL RECEPTOR BETA-CHAIN GENES
SO NATURE
LA English
DT Article
ID antigen receptor; lymphocytes-t; thymocyte development; signal transduction; transgenic mice; expression; p56lck; alpha; lambda-5; surface
AB DURING T-cell development, site-specific DNA rearrangements mediating assembly of beta- and alpha-chain genes of the T-cell receptor (TCR) are developmentally ordered1,2. In particular, assembly and expression of a complete beta-chain gene blocks further rearrangements at the beta-locus (a process referred to as allelic exclusion)3 and drives the generation and expansion of CD4+8+ cells4,5. Although the mechanism used by TCRbeta chains to deliver such signals is unknown, studies in transgenic animals have suggested that the lymphocyte-specific protein tyrosine kinase p56lck may impinge on a similar signalling pathway6. The hypothesis that TCRbeta chains deliver intracellular signals via p56lck makes an explicit prediction: that interference with p56lck function will mitigate the effects of a simultaneously expressed TCRbeta chain. Here we confirm this prediction through examination of allelic exclusion in mice expressing both a functional TCRbeta chain transgene and a catalytically inactive form of p56lck.
C1 UNIV WASHINGTON,SCH MED SL15,HOWARD HUGHES MED INST,SEATTLE,WA 98195.
   UNIV WASHINGTON,SCH MED SL15,DEPT IMMUNOL,SEATTLE,WA 98195.
   UNIV WASHINGTON,SCH MED SL15,DEPT BIOCHEM,SEATTLE,WA 98195.
   UNIV WASHINGTON,SCH MED SL15,DEPT MED MED GENET,SEATTLE,WA 98195.
C3 University of Washington; University of Washington Seattle; Howard Hughes Medical Institute; University of Washington; University of Washington Seattle; University of Washington; University of Washington Seattle; University of Washington; University of Washington Seattle
NR 28
TC 138
Z9 146
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 552
EP 554
DI 10.1038/365552a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100056
PM 8413611
DA 2026-03-10
ER

PT J
AU GOLDBERG, YP
   ROMMENS, JM
   ANDREW, SE
   HUTCHINSON, GB
   LIN, BY
   THEILMANN, J
   GRAHAM, R
   GLAVES, ML
   STARR, E
   MCDONALD, H
   NASIR, J
   SCHAPPERT, K
   KALCHMAN, MA
   CLARKE, LA
   HAYDEN, MR
AF GOLDBERG, YP
   ROMMENS, JM
   ANDREW, SE
   HUTCHINSON, GB
   LIN, BY
   THEILMANN, J
   GRAHAM, R
   GLAVES, ML
   STARR, E
   MCDONALD, H
   NASIR, J
   SCHAPPERT, K
   KALCHMAN, MA
   CLARKE, LA
   HAYDEN, MR
TI IDENTIFICATION OF AN ALU RETROTRANSPOSITION EVENT IN CLOSE PROXIMITY TO A STRONG CANDIDATE GENE FOR HUNTINGTONS-DISEASE
SO NATURE
LA English
DT Article
ID dna-sequences; insertion; regions; family; d4s95
AB HUNTINGTON'S disease (HD) is a late-onset autosomal dominant neuropsychiatric disorder presenting in mid-adult life with personality disturbance and involuntary movements, cognitive and affective disturbance, and inexorable progression to death1. The underlying genetic defect has been mapped to chromosomal band 4p16.3 (refs 2, 3). Analysis of specific recombination events in some families with HD has further refined the location of the HD defect to a 2.2 megabase DNA interval4,5. Using a direct complementary DNA selection strategy we have identified at least seven transcriptional units within the minimal region believed to contain the HD gene. Screening with one of the cDNA clones identified an Alu insertion in genomic DNA from two persons with HD which showed complete cosegregation with the disease in these families but was not found in 1,000 control chromosomes. Two genes including the previously identified alpha-adducin gene and another that encodes for a 12-kilobase transcript, map in close proximity to the Alu insertion site. The 12-kilobase transcript should be regarded as a strong candidate for the HD gene.
C1 HOSP SICK CHILDREN,DEPT GENET,TORONTO M5G 1X8,ONTARIO,CANADA.
   UNIV BRITISH COLUMBIA,DEPT MED GENET,VANCOUVER V6T 1Z4,BC,CANADA.
C3 University of Toronto; Hospital for Sick Children (SickKids); University of British Columbia
NR 25
TC 41
Z9 49
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 370
EP 373
DI 10.1038/362370a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600070
PM 8384324
DA 2026-03-10
ER

PT J
AU TSUBATA, T
   WU, J
   HONJO, T
AF TSUBATA, T
   WU, J
   HONJO, T
TI B-CELL APOPTOSIS INDUCED BY ANTIGEN RECEPTOR CROSS-LINKING IS BLOCKED BY A T-CELL SIGNAL THROUGH CD40
SO NATURE
LA English
DT Article
ID invitro tolerance induction; lymphocytes-b; transgenic mouse; activation; immunoglobulin; ligand; expression; protein; death; proliferation
AB IN mice transgenic for an autoantibody, self-reactive B cells have been shown to be eliminated upon interaction with membrane-bound self-antigens in the periphery1,2 as well as in the bone marrow3,5, suggesting that both immature and mature B cells are eliminated by multimerization of surface immunoglobulins (sIg). Activation of mature B cells by antigens may thus require a second signal that inhibits sIg-mediated apoptosis. Such a second signal is likely to be provided by T helper cells, because B-cell tolerance is more easily induced in the absence of T helper cells6-9. To assess the molecular nature of the signal that inhibits sIg-mediated apoptosis, we used anti-IgM-induced apoptotic death of WEHI-231 B lymphoma cells10,11 as a model system. Here we report that the signal for abrogating sIg-mediated apoptosis is generated by association of the CD40L molecule on T cells with the CD40 molecule on WEHI-231 cells. T-cell help through CD40 may thus determine whether B cells are eliminated or activated upon interaction with antigens.
RP TSUBATA, T (corresponding author), KYOTO UNIV, FAC MED, DEPT MED CHEM, KYOTO 606, JAPAN.
NR 35
TC 391
Z9 416
U1 0
U2 4
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 645
EP 648
DI 10.1038/364645a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100058
PM 7688865
DA 2026-03-10
ER

PT J
AU KUO, CC
   BEAN, BP
AF KUO, CC
   BEAN, BP
TI G-PROTEIN MODULATION OF ION PERMEATION THROUGH N-TYPE CALCIUM CHANNELS
SO NATURE
LA English
DT Article
ID chick sensory neurons; gtp-binding protein; sympathetic neurons; hippocampal-neurons; inhibition; currents; receptor; conductance; mechanism
AB N-TYPE calcium channels in cell membranes are inhibited by neurotransmitters such as noradrenaline1-4, luteinizing hormone-releasing (LHRH)5-7, gamma-aminobutyric acid (GABA)8,9 and glutamate10,11. Although GTP-binding proteins (G proteins) are probably the common mediators of such inhibition6,11-14, it is unclear exactly bow G proteins alter the operation of the channel. Various experiments have shown changes in channel gating2-6,15,16. Here we show that inward current carried by Na+ through N-type channels was far less inhibited by LHRH or by internal GTP-gammaS than was current carried by Ba2+. With external Ba2+ and internal Cs+, LHRH inhibited the Ba2+-carried inward limb of the instantaneous current-voltage curve much more than the Cs+-carried outward limb. Noise analysis showed that LHRH or GTP-gammaS decrease single-channel current carried by Ba2+. These results suggest that alteration of the ion permeation pathway contributes significantly to G-protein inhibition of N-type Ca2+ channels.
RP KUO, CC (corresponding author), HARVARD UNIV,SCH MED,DEPT NEUROBIOL,200 LONGWOOD AVE,BOSTON,MA 02115, USA.
NR 26
TC 69
Z9 71
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 258
EP 262
DI 10.1038/365258a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100056
PM 8396731
DA 2026-03-10
ER

PT J
AU AMMALA, C
   ASHCROFT, FM
   RORSMAN, P
AF AMMALA, C
   ASHCROFT, FM
   RORSMAN, P
TI CALCIUM-INDEPENDENT POTENTIATION OF INSULIN RELEASE BY CYCLIC-AMP IN SINGLE BETA-CELLS
SO NATURE
LA English
DT Article
ID secretion; ca-2+; camp; exocytosis; activation; interplay; currents
AB How does cyclic AMP potentiate insulin secretion from pancreatic islet beta-cells? This question is fundamental to understanding how hormones such as glucagon, which elevates cAMP1, stimulate insulin secretion and so contribute to the normal secretory response of the islet2,3. It is well established that a rise in the cytoplasmic Ca2+ concentration ([Ca2+]i) is essential for insulin secretion4 and therefore cAMP has been proposed to act by elevating [Ca2+]i. But studies on permeabilized beta-cells indicate that cAMP increases insulin release even when [Ca2+]i is held constant5,6. We have used microfluorimetry and the patch-clamp technique to measure changes simultaneously in Ca2+ currents, [Ca2+]i and exocytosis7-9 in a single beta-cell in response to cAMP. We show here that cAMP, through activation of protein kinase A, increases Ca2+-influx through voltage-dependent L-type Ca2+ channels, thereby elevating [Ca2+]i and accelerating exocytosis. More importantly, cAMP also promotes insulin release by a direct interaction with the secretory machinery, which accounts for as much as 80% of its effect.
C1 DEPT MED BIOPHYS,MEDICINAREGATAN 11,S-41390 GOTHENBURG,SWEDEN.
   UNIV OXFORD,PHYSIOL LAB,OXFORD OX1 3PT,ENGLAND.
C3 University of Oxford
NR 23
TC 359
Z9 391
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 356
EP 358
DI 10.1038/363356a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700055
PM 7684514
DA 2026-03-10
ER

PT J
AU JOUZEL, J
   BARKOV, NI
   BARNOLA, JM
   BENDER, M
   CHAPPELLAZ, J
   GENTHON, C
   KOTLYAKOV, VM
   LIPENKOV, V
   LORIUS, C
   PETIT, JR
   RAYNAUD, D
   RAISBECK, G
   RITZ, C
   SOWERS, T
   STIEVENARD, M
   YIOU, F
   YIOU, P
AF JOUZEL, J
   BARKOV, NI
   BARNOLA, JM
   BENDER, M
   CHAPPELLAZ, J
   GENTHON, C
   KOTLYAKOV, VM
   LIPENKOV, V
   LORIUS, C
   PETIT, JR
   RAYNAUD, D
   RAISBECK, G
   RITZ, C
   SOWERS, T
   STIEVENARD, M
   YIOU, F
   YIOU, P
TI EXTENDING THE VOSTOK ICE-CORE RECORD OF PALEOCLIMATE TO THE PENULTIMATE GLACIAL PERIOD
SO NATURE
LA English
DT Article
ID last climatic cycle; antarctic ice; co2; age; constraints; be-10; dust
AB The ice-core record of local temperature, dust accumulation and air composition at Vostok station, Antarctica, now extends back to the penultimate glacial period (approximately 140-200 kyr ago) and the end of the preceding interglacial. This yields a new glaciological timescale for the whole record, which is consistent with ocean records. Temperatures at Vostok appear to have been more uniformly cold in the penultimate glacial period than in the most recent one. Concentrations of CO2 and CH4 Correlate well with temperature throughout the record.
C1 ST PETERSBURG ARCTIC & ANTARCTIC RES INST,ST PETERSBURG 199226,RUSSIA.
   CNRS,GLACIOL & GEOPHYS ENVIRONNEMENT LAB,F-38402 ST MARTIN DHERES,FRANCE.
   UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882.
   MOSCOW GEOG INST,MOSCOW 109017,RUSSIA.
   CTR SPECTROMETRIE NUCL & SPECTROMETRIE MASSE,F-91405 ORSAY,FRANCE.
C3 Arctic & Antarctic Research Institute; Centre National de la Recherche Scientifique (CNRS); University of Rhode Island; Institute of Geography, Russian Academy of Sciences; Universite Paris Saclay
RP JOUZEL, J (corresponding author), CTR ETUD SACLAY,DSM,CEA,MODELISAT CLIMAT & ENVIRONNEMENT LAB,F-91191 GIF SUR YVETTE,FRANCE.
NR 50
TC 439
Z9 466
U1 2
U2 64
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 407
EP 412
DI 10.1038/364407a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000044
DA 2026-03-10
ER

PT J
AU KIM, CWA
   BERG, JM
AF KIM, CWA
   BERG, JM
TI THERMODYNAMIC BETA-SHEET PROPENSITIES MEASURED USING A ZINC-FINGER HOST PEPTIDE
SO NATURE
LA English
DT Article
ID helix-forming tendency; occurring amino-acids; globular-proteins; secondary structure; dependent structure; preferences; stability
AB THE three-dimensional structures of proteins reveal that the distribution of amino acids within the major classes of secondary structure is not random but that each amino acid has its own preferred secondary structural arrangements1-5. Propensity scales for residues in alpha-helices have been generated through the use of various host-guest systems6-9. Here we measure the thermodynamic beta-sheet propensities of each of the twenty commonly occurring amino acids. A previously studied zinc-finger peptide10 was used as the host system in which amino acids were substituted into a guest site, a solvent-exposed position in an antiparallel beta-sheet. As these peptides are unfolded in the absence of bound metal but are folded in their presence, it is assumed that the thermodynamics of metal binding fully reflect peptide-folding energy. A competitive cobalt(II)-binding assay was used to determine these energies with high precision. The relative free energies correlate well with previously derived potential values based on statistical analysis of protein structures. We are therefore able to present a thermodynamic beta-sheet propensity scale for all the commonly occurring amino acids in aqueous solution.
C1 JOHNS HOPKINS UNIV,SCH MED,DEPT BIOPHYS & BIOPHYS CHEM,BALTIMORE,MD 21205.
C3 Johns Hopkins University
RP KIM, CWA (corresponding author), JOHNS HOPKINS UNIV,DEPT CHEM,34TH & CHARLES ST,BALTIMORE,MD 21218, USA.
NR 19
TC 342
Z9 411
U1 0
U2 32
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 267
EP 270
DI 10.1038/362267a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600063
PM 8459852
DA 2026-03-10
ER

PT J
AU PLOWMAN, GD
   GREEN, JM
   CULOUSCOU, JM
   CARLTON, GW
   ROTHWELL, VM
   BUCKLEY, S
AF PLOWMAN, GD
   GREEN, JM
   CULOUSCOU, JM
   CARLTON, GW
   ROTHWELL, VM
   BUCKLEY, S
TI HEREGULIN INDUCES TYROSINE PHOSPHORYLATION OF HER4/P180(ERBB4)
SO NATURE
LA English
DT Article
ID growth-factor; egf receptor; p185erbb2; cloning
AB THE HER4/ERBB4 gene encodes a 180K transmembrane protein (HER4/p180erbB4) that is structurally related to the 185K product (HER2/p185erbB2) of the HER2/ERBB2 proto-oncogene1. A 45K heparin-binding glycoprotein (p45) has been characterized that specifically activates the intrinsic tyrosine kinase activity of HER4 (ref. 2). This HER4 ligand shares several features with the heregulin family of proteins, including molecular mass, ability to induce differentiation of breast cancer cells, activation of tyrosine phosphorylation in MDA-MB453 cells, and amino-terminal protein sequence. Heregulin exists as multiple isoforms and all are presumed to interact directly with HER2 (refs 3-6). We have used binding and phosphorylation studies with recombinant ligand on cell lines expressing recombinant receptors, and report here that heregulin, like p45, is a specific ligand for HER4. Furthermore, heregulin fails to induce phosphorylation of HER2 in the absence of HER4. These findings suggest that activation of the HER4 receptor is involved in signal transduction by heregulin.
RP PLOWMAN, GD (corresponding author), BRISTOL MYERS SQUIBB PHARMACEUT RES INST,3005 1ST AVE,SEATTLE,WA 98121, USA.
NR 13
TC 471
Z9 559
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 473
EP 475
DI 10.1038/366473a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800067
PM 7902537
DA 2026-03-10
ER

PT J
AU CAMERON, DL
   WILLIAMS, JT
AF CAMERON, DL
   WILLIAMS, JT
TI DOPAMINE D1 RECEPTORS FACILITATE TRANSMITTER RELEASE
SO NATURE
LA English
DT Article
ID rat substantia nigra; potassium conductance; synaptic inputs; d2 receptors; neurons; agonist; activation; depression; mechanism; responses
AB A PHYSIOLOGICAL role for the dopamine D1 receptor has been difficult to define, particularly because of its complex pre- and postsynaptic localization in brain areas such as the striatum1. In the midbrain, however, D1 receptors are selectively localized to the terminals of GABA (gamma-aminobutyric acid)-containing afferents2-4. We have studied the actions of these D1 receptors on evoked GABA synaptic potentials recorded intracellularly from dopamine neurons in the ventral tegmental area (VTA). We report here that dopamine augmented GABA(B) inhibitory postsynaptic potentials (i.p.s.ps) in the presence of D2 receptor antagonists. This effect was mimicked by the D1 agonists SKF38393 and SKF82958 and blocked by the D1 antagonists SCH23390 and cis-flupenthixol. No modulation of the GABA(A) synaptic potential was observed. The postsynaptic actions of the GABA(B) agonist, baclofen, were unaffected by SKF38393, SCH23390 or cis-flupenthixol, confirming a presynaptic locus of D1 action. Additionally, D1 antagonists reduced the amplitude of the GABA(B) i.p.s.p. in the absence of D1 agonists. We conclude that dopamine acts tonically at presynaptic D1 receptors on the terminals of afferent GABA neurons to facilitate selectively GABA(B)-mediated neurotransmission in the midbrain.
C1 OREGON HLTH SCI UNIV,VOLLUM INST ADV BIOMED RES,PORTLAND,OR 97201.
C3 Oregon Health & Science University
NR 29
TC 251
Z9 273
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 344
EP 347
DI 10.1038/366344a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500049
PM 8247128
DA 2026-03-10
ER

PT J
AU LOCKWOOD, M
   DENIG, WF
   FARMER, AD
   DAVDA, VN
   COWLEY, SWH
   LUHR, H
AF LOCKWOOD, M
   DENIG, WF
   FARMER, AD
   DAVDA, VN
   COWLEY, SWH
   LUHR, H
TI IONOSPHERIC SIGNATURES OF PULSED RECONNECTION AT THE EARTHS MAGNETOPAUSE
SO NATURE
LA English
DT Article
ID low-altitude signatures; flux-transfer events; dayside magnetopause; boundary-layer; cusp; plasma; convection
AB THE plasma precipitating into the Earth's dayside auroral atmosphere has characteristics which show that it originates from the shocked solar-wind plasma of the magnetosheath1,2 . The particles of the magnetosheath plasma precipitate down a funnel-shaped region (cusp) of open field lines resulting from reconnection of the geomagnetic field with the interplanetary magnetic field3 Although the cusp has long been considered a well defined spatial structure maintained by continuous reconnection, it has recently been suggested4-6 that reconnection instead may take place in a series of discontinuous events; this is the 'pulsating cusp model'. Here we present coordinated radar and satellite observations of a series of discrete, poleward-moving plasma structures that are consistent with the pulsating-cusp model.
C1 PHILLIPS LAB, PL-GPSG, BEDFORD, MA 01731 USA.
   UCL, ATMOSPHER PHYS LAB, LONDON W1P 7PP, ENGLAND.
   UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, BLACKETT LAB, LONDON SW7 2BZ, ENGLAND.
   TECH UNIV BRAUNSCHWEIG, INST GEOPHYS & METEOROL, W-3300 BRAUNSCHWEIG, GERMANY.
C3 University of London; University College London; Imperial College London; Braunschweig University of Technology
RP LOCKWOOD, M (corresponding author), RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND.
NR 26
TC 109
Z9 115
U1 0
U2 5
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 424
EP 428
DI 10.1038/361424a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300051
DA 2026-03-10
ER

PT J
AU WERNER, BT
   HALLET, B
AF WERNER, BT
   HALLET, B
TI NUMERICAL-SIMULATION OF SELF-ORGANIZED STONE STRIPES
SO NATURE
LA English
DT Article
ID soils
AB GEOMETRICALLY regular stripes of stones are found on many unvegetated alpine and polar hillslopes; known as 'sorted stripes' because of the characteristic textural sorting between surface stones and fine-grained soil, they contrast markedly with the lack of order typical of natural landscapes. The spacing of the stripes can range from centimetres to metres (about 10-20 times the average stone diameter1,2), with individual stripes extending down-slope for many tens of metres (Fig. 1). A variety of formative mechanisms have been proposed3, but it is still unclear how such orderly stripes can arise spontaneously, and what dictates the spacing. Here we present two-dimensional computer simulations in which the displacement of surface stones is governed by the preferential growth of needle-ice in stone-free regions of soil during each freezing cycle. Regular patterns of stones and soil that closely resemble natural stripes are found to emerge spontaneously from the model as a result of identifiable feedbacks between soil texture, ice growth and local slope.
C1 UNIV WASHINGTON,QUATERNARY RES CTR,SEATTLE,WA 98195.
C3 University of Washington; University of Washington Seattle
RP WERNER, BT (corresponding author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,CTR COASTAL STUDIES 0209,LA JOLLA,CA 92093, USA.
NR 15
TC 69
Z9 70
U1 1
U2 31
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 142
EP 145
DI 10.1038/361142a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600055
DA 2026-03-10
ER

PT J
AU ROSS, K
   ELTHON, D
AF ROSS, K
   ELTHON, D
TI CUMULATES FROM STRONGLY DEPLETED MID-OCEAN-RIDGE BASALT
SO NATURE
LA English
DT Article
AB RECENT studies of abyssal peridotites1, mid-ocean-ridge basalts (MORBs)2 and their entrained melt inclusions3,4 have shown that fractional melting of the upwelling sub-oceanic mantle produces magmas with a much wider range of compositions than erupted MORBs. In particular, it seems that strongly depleted primary magmas are routinely produced by melting beneath ridges1. The absence of strongly depleted melts as erupted lavas prompts the question of how long such magmas survive beneath ridges, before their distinctive compositions are concealed by mixing with more enriched magmas. Here we report mineral compositions from a unique suite of oceanic cumulates recovered from DSDP Site 334 (ref. 5), which indicate that the rocks crystallized from basaltic liquids that were strongly depleted in Na, Ti, Zr, Y, Sr and rare-earth elements relative to any erupted MORB. It thus appears that the magmatic plumbing system beneath the Mid-Atlantic Ridge permitted strongly depleted magmas to accumulate in a magma chamber and remain sufficiently isolated to produce cumulate rocks. Even so, spatial heterogeneity in the compositions of high-calcium pyroxenes suggests that in the later stages of solidification these rocks reacted with infiltrating enriched basaltic liquids.
C1 UNIV HOUSTON,DEPT CHEM,HOUSTON,TX 77204.
   UNIV HOUSTON,TEXAS CTR SUPERCONDUCT,HOUSTON,TX 77204.
C3 University of Houston System; University of Houston; University of Houston System; University of Houston
RP ROSS, K (corresponding author), UNIV HOUSTON,DEPT GEOSCI,HOUSTON,TX 77204, USA.
NR 30
TC 87
Z9 92
U1 0
U2 16
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 826
EP 829
DI 10.1038/365826a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100046
DA 2026-03-10
ER

PT J
AU BRENNER, S
   ELGAR, G
   SANDFORD, R
   MACRAE, A
   VENKATESH, B
   APARICIO, S
AF BRENNER, S
   ELGAR, G
   SANDFORD, R
   MACRAE, A
   VENKATESH, B
   APARICIO, S
TI CHARACTERIZATION OF THE PUFFERFISH (FUGU) GENOME AS A COMPACT MODEL VERTEBRATE GENOME
SO NATURE
LA English
DT Article
ID mammalian genm; dna-sequence; microsatellites; evolution
AB CLONING and sequencing techniques now allow us to characterize genes directly instead of having to deduce their properties from their effects. This new genetics reaches its apotheosis in the plan to obtain the complete DNA sequence of the human genome, but this is far beyond the capacity of present sequencing methods. Small 'model' genomes, such as those of Escherichia coli (4.7 megabases (Mb)1 and yeast (14 Mb)2, or even those of Caenorhabditis elegans (100 Mb) and Drosophila (165 Mb), are better scaled to existing technology. The yeast genome will contain genes with functions common to all eukaryotic cells, and those of simple multicellular organisms may throw light on the genetic specification of more complex functions. However, vertebrates differ in their morphology and development, so the ideal model would be a vertebrate genome of minimum size and complexity but with maximum homology to the human genome. Here we report the characterization of the small genome (400 Mb) of the tetraodontoid fish, Fugu rubripes5. A random sequencing approach supported by gene probing shows that the haploid genome contains 400 Mb of DNA, of which more that 90% is unique. This genome is 7.5 times smaller than the human genome and because it has a similar gene repertoire it is the best model genome for the discovery of human genes.
C1 UNIV CAMBRIDGE, ADDENBROOKES HOSP, SCH CLIN, MRC, MOLEC GENET UNIT, CAMBRIDGE CB2 2QQ, ENGLAND.
C3 University of Cambridge; Cambridge University Hospitals NHS Foundation Trust; Addenbrooke's Hospital
RP BRENNER, S (corresponding author), UNIV CAMBRIDGE, ADDENBROOKES HOSP, SCH CLIN, DEPT MED, CAMBRIDGE CB2 2QQ, ENGLAND.
NR 19
TC 497
Z9 558
U1 0
U2 29
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 265
EP 268
DI 10.1038/366265a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500063
PM 8232585
DA 2026-03-10
ER

PT J
AU CAVARELLI, J
   REES, B
   RUFF, M
   THIERRY, JC
   MORAS, D
AF CAVARELLI, J
   REES, B
   RUFF, M
   THIERRY, JC
   MORAS, D
TI YEAST TRANSFER RNA(ASP) RECOGNITION BY ITS COGNATE CLASS-II AMINOACYL-TRANSFER RNA-SYNTHETASE
SO NATURE
LA English
DT Article
ID asparaginyl-transfer-rna; escherichia-coli; crystal-structure; crystallographic refinement; 2.8-a resolution; sequence; identity; homology; atp
AB AMINOACYL-RNA synthetases can be divided into two classes according to structural features inferred from sequence alignments1-3. This classification correlates almost perfectly with the attachment of the amino acid to the 2'-OH (class I) or 3'-OH (class II) group of the terminal adenosine4-6. Six subgroups of higher homology can be inferred from sequence analysis7,8. The five aminoacyl-tRNA synthetases whose crystal structures are known (MetRS, TyrRS and GlnRS in class I, SerRS and AspRS in class II)9-13 belong to different subgroups. Two of them, GluRS and AspRS, have been cocrystallized with their cognate tRNA11,13. AspRS, like six other members of class II, is an alpha2 dimer. Yeast tRNA(Asp) exhibits five identity determinants: the three anticodon bases, the discriminator base G73 and the base pair G10-U25(14). We report here that the refined crystal structure of AspRS complexed with TRNA(Asp) at 2.9 angstrom resolution reveals three regions of contact, each involving a domain of AspRS and at least one identity determinant of tRNA(Asp). The mode of binding of the acceptor stem of tRNA(Asp) by AspRS can be generalized to class II aminoacyl-tRNA synthetases, whereas the deciphering of the anticodon, which involves a large conformational change of the loop and the formation of a bulge, is more specific to the aspartic system.
C1 IBMC,BIOL STRUCT LAB,STRASBOURG,FRANCE.
NR 29
TC 278
Z9 282
U1 0
U2 18
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 181
EP 184
DI 10.1038/362181a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800067
PM 8450889
DA 2026-03-10
ER

PT J
AU MEDIAVILLA, E
   ARRIBAS, S
AF MEDIAVILLA, E
   ARRIBAS, S
TI EVIDENCE FOR AN OFFSET ACTIVE NUCLEUS IN THE SEYFERT-GALAXY NGC3227
SO NATURE
LA English
DT Article
ID narrow-line region; bidimensional spectroscopy; emission-line; kinematics; profiles; gas
AB THE active nuclei of Seyfert 1 galaxies are characterized by a small (approximately 0.03 pc) region of intense broad emission lines, indicative of gas moving at extremely high velocities and ionized by a non-thermal radiation field. These spectral features are usually explained by invoking the presence of a central supermassive black hole. Here we present two-dimensional spectra of the Seyfert galaxy NGC3227, from which we have calculated the intensity maps of the emission lines, and the velocity field representing the motion of gas within the central kiloparsec of the galaxy. Surprisingly, we find that the region of broad emission lines is offset from the kinematic centre by about 250 pc, suggesting that the putative supermassive black hole is displaced from the true galactic centre. Possible explanations of this finding include the transient migration of the black hole from the galactic centre, a black hole in orbit about a central concentration of dark matter, or the capture of the black hole during the merger of NGC3227 with another galaxy.
RP MEDIAVILLA, E (corresponding author), INST ASTROFIS CANARIAS,E-38200 LA LAGUNA,SPAIN.
NR 22
TC 26
Z9 26
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 420
EP 422
DI 10.1038/365420a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300048
DA 2026-03-10
ER

PT J
AU WHITEHEART, SW
   GRIFF, IC
   BRUNNER, M
   CLARY, DO
   MAYER, T
   BUHROW, SA
   ROTHMAN, JE
AF WHITEHEART, SW
   GRIFF, IC
   BRUNNER, M
   CLARY, DO
   MAYER, T
   BUHROW, SA
   ROTHMAN, JE
TI SNAP FAMILY OF NSF ATTACHMENT PROTEINS INCLUDES A BRAIN-SPECIFIC ISOFORM
SO NATURE
LA English
DT Article
ID sensitive fusion protein; vesicular transport; requires; purification; receptor
AB THE soluble NSF attachment proteins (SNAPs) enable N-ethyl-maleimide-sensitive fusion protein (NSF) to bind to target membranes1-3. Here we report the cloning and sequencing of complementary DNAs encoding alpha-, beta- and gamma-SNAPs. Two of these proteins, alpha and gamma, are found in a wide range of tissues, and act synergistically in intra-Golgi transport. The third, beta, is a brain-specific isoform of alpha-SNAP. Thus, NSF and SNAPs appear to be general components of the intracellular membrane fusion apparatus, and their action at specific sites of fusion must be controlled by SNAP receptors particular to the membranes being fused, as described in the accompanying article4.
RP WHITEHEART, SW (corresponding author), MEM SLOAN KETTERING CANC CTR,ROCKEFELLER RES LAB,1275 YORK AVE,NEW YORK,NY 10021, USA.
NR 14
TC 241
Z9 273
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 353
EP 355
DI 10.1038/362353a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600064
PM 8455721
DA 2026-03-10
ER

PT J
AU MARONE, C
   KILGORE, B
AF MARONE, C
   KILGORE, B
TI SCALING OF THE CRITICAL SLIP DISTANCE FOR SEISMIC FAULTING WITH SHEAR STRAIN IN FAULT ZONES
SO NATURE
LA English
DT Article
ID gouge; instability; friction; velocity; behavior
AB THEORETICAL and experimentally based laws for seismic faulting contain a critical slip distance1-5, D(c), which is the slip over which strength breaks down during earthquake nucleation. On an earthquake-generating fault, this distance plays a key role in determining the rupture nucleation dimension6, the amount of premonitory and post-seismic slip7-10, and the maximum seismic ground acceleration1,11. In laboratory friction experiments, D(c) has been related to the size of surface contact junctions2,5,12; thus,the discrepancy between laboratory measurements of D(c) (approximately 10(-5) m) and values obtained from modelling earthquakes (approximately 10(-2) m) has been attributed to differences in roughness between laboratory surfaces and natural faults5. This interpretation predicts a dependence of D(c) on the particle size of fault gouge2 (breccia and wear material) but not on shear strain. Here we present experimental results showing that D(c) scales with shear strain in simulated fault gouge. Our data suggest a new physical interpretation for the critical slip distance, in which Dc is controlled by the thickness of the zone of localized shear strain. As gouge zones of mature faults are commonly 10(2)-10(3) m thick13-17, whereas laboratory gouge layers are 1-10 mm thick, our data offer an alternative interpretation of the discrepancy between laboratory and field-based estimates of D(c).
C1 US GEOL SURVEY,MENLO PK,CA 94025.
C3 United States Department of the Interior; United States Geological Survey
RP MARONE, C (corresponding author), MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139, USA.
NR 36
TC 345
Z9 381
U1 1
U2 51
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 618
EP 621
DI 10.1038/362618a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800042
DA 2026-03-10
ER

PT J
AU SWARTZ, DA
   CLOCCHIATTI, A
   BENJAMIN, R
   LESTER, DF
   WHEELER, JC
AF SWARTZ, DA
   CLOCCHIATTI, A
   BENJAMIN, R
   LESTER, DF
   WHEELER, JC
TI SUPERNOVA-1993J AS A SPECTROSCOPIC LINK BETWEEN TYPE-II AND TYPE-IB SUPERNOVAE
SO NATURE
LA English
DT Article
ID standard stars; helium; spectrophotometry; phase
AB SUPERNOVA 1993J in the nearby galaxy M81 is one of the closest-and hence brightest-supernovae to be witnessed this century. The early spectrum of SN1993J showed1-3 the characteristic hydrogen signature of type II supernovae, but its subsequent evolution is atypical for this class of supernova. Here we present optical and infrared spectra of SN1993J up to 43 days after outburst, which reveal the onset of the helium absorption and emission features more commonly associated with hydrogen-free type Ib supernovae. Corresponding model spectra show that the progenitor star must have possessed an unusually thin (for type II supernovae) hydrogen-rich envelope overlying a helium-rich mantle. Moreover, the supernova ejecta must have remained compositionally stratified, with little transport of the hydrogen-rich material down into the underlying helium layer, or mixing of heavier elements (such as radioactive Ni-56) outwards. SN1993J therefore represents a transition object between hydrogen-dominated type II supernovae, and hydrogen-free, helium-dominated type Ib supernovae.
C1 UNIV TEXAS,DEPT ASTRON,AUSTIN,TX 78712.
C3 University of Texas System; University of Texas Austin
RP SWARTZ, DA (corresponding author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,SPACE SCI LAB,HUNTSVILLE,AL 35812, USA.
NR 24
TC 64
Z9 67
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 232
EP 234
DI 10.1038/365232a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100046
DA 2026-03-10
ER

PT J
AU SHAM, TK
   JIANG, DT
   COULTHARD, I
   LORIMER, JW
   FENG, XH
   TAN, KH
   FRIGO, SP
   ROSENBERG, RA
   HOUGHTON, DC
   BRYSKIEWICZ, B
AF SHAM, TK
   JIANG, DT
   COULTHARD, I
   LORIMER, JW
   FENG, XH
   TAN, KH
   FRIGO, SP
   ROSENBERG, RA
   HOUGHTON, DC
   BRYSKIEWICZ, B
TI ORIGIN OF LUMINESCENCE FROM POROUS SILICON DEDUCED BY SYNCHROTRON-LIGHT-INDUCED OPTICAL LUMINESCENCE
SO NATURE
LA English
DT Article
ID emission
AB FOLLOWING reports of intense optical luminescence from porous silicon1,2, the opportunity for engineering optoelectronic devices using this material3,4 has attracted considerable attention. At present, however, the question of the origin of the luminescence has not been fully resolved5. The quantum-confinement model6-8 suggests that a quantum size effect gives optical transitions, and hence luminescence, in the visible range - this idea gains support from the wavelength dependence of the luminescence on porosity. An alternative model9,10 attributes the luminescence to siloxene-like compounds11 formed on the silicon surface. A third model, which invokes hydrogenated amorphous silicon as a possible source12,13, seems to be contradicted by X-ray absorption fine structure (XAFS) studies14-16. Here we report optical luminescence in porous silicon and siloxene induced by soft X-rays with energies near the silicon K-edge (1,839 eV). Using the luminescence together with the total electron yield, we can obtain the XAFS spectra for the luminescent sites in both materials. Our results show that the luminescence from porous silicon does not derive from siloxene (either freshly prepared or annealed), and thus suggest that the quantum-confinement model seems to provide the only viable explanation.
C1 UNIV WISCONSIN MADISON,CTR SYNCHROTRON RADIAT,STOUGHTON,WI 53589.
   ARGONNE NATL LAB,ARGONNE,IL 60439.
   NATL RES COUNCIL CANADA,INST MICROSTRUCT SCI,OTTAWA K1A 0R6,ONTARIO,CANADA.
C3 University of Wisconsin System; University of Wisconsin Madison; United States Department of Energy (DOE); Argonne National Laboratory; National Research Council Canada
RP SHAM, TK (corresponding author), UNIV WESTERN ONTARIO,DEPT CHEM,LONDON N6A 5B7,ONTARIO,CANADA.
NR 28
TC 197
Z9 216
U1 0
U2 39
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 331
EP 334
DI 10.1038/363331a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700046
DA 2026-03-10
ER

PT J
AU SHIMMIN, LC
   CHANG, BHJ
   LI, WH
AF SHIMMIN, LC
   CHANG, BHJ
   LI, WH
TI MALE-DRIVEN EVOLUTION OF DNA-SEQUENCES
SO NATURE
LA English
DT Article
ID molecular evolution; rates
AB IT is commonly believed1,2 that the mutation rate is much higher in the human male germ line than in the female germ line because the number of germ-cell divisions per generation is much larger in males than in females. But direct estimation of mutation rates is difficult, relying mainly on sex-linked genetic diseases3, so the ratio (alpha(m)) of male to female mutation rates is not clear. It has been noted4 that if alpha(m). is very large, then the rate of synonymous substitution in X-linked genes should be only 2/3 of that in autosomal genes, and comparison of human and rodent genes supported this prediction4. As the number of X-linked genes used in the study was small and the X-linked and autosomal sequences were non-homologous, and given that the synonymous rate varies among genes5, we sequenced the last intron (approximately 1 kb) of the Y-linked and X-linked zinc-finger-protein genes (ZFY and ZFX) in humans, orang-utans, baboons and squirrel monkeys. The ratio Y/X of the substitution rate in the Y-linked intron to that in the X-linked intron is approximately 2.3, which is close to that estimated from synonymous rates in the ZFY and ZFX genes6-8 and implies alpha(m) almost-equal-to 6. This estimate of alpha(m) supports the view that the evolution of DNA sequences in higher primates is male-driven. It is, however, much lower than the previous estimate4 and therefore raises a number of issues.
C1 UNIV TEXAS, CTR DEMOG & POPULAT GENET, POB 20334, HOUSTON, TX 77225 USA.
C3 University of Texas System; University of Texas Health Science Center Houston
NR 18
TC 203
Z9 219
U1 0
U2 8
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 745
EP 747
DI 10.1038/362745a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000054
PM 8469284
DA 2026-03-10
ER

PT J
AU WEINZIERL, ROJ
   DYNLACHT, BD
   TJIAN, R
AF WEINZIERL, ROJ
   DYNLACHT, BD
   TJIAN, R
TI LARGEST SUBUNIT OF DROSOPHILA TRANSCRIPTION FACTOR-IID DIRECTS ASSEMBLY OF A COMPLEX CONTAINING TBP AND A COACTIVATOR
SO NATURE
LA English
DT Article
ID binding-protein; tfiid complex; activation; gene; mechanism; upstream
AB The TFIID complex consists of the TATA-binding protein (TBP) and associated factors (TAFs) serving to mediate transcriptional activation by promoter-specific regulators. Here we report the cloning of Drosophila TAF(II)250 and the assembly of a partial complex containing recombinant TBP, TAF(II)110 and the C-terminal domain of TAF(II)250. This triple complex supports Sp1 activation and reveals specific interactions between TAF(II)250, TBP and TAF(II)110.
RP WEINZIERL, ROJ (corresponding author), UNIV CALIF BERKELEY,HOWARD HUGHES MED INST,DEPT MOLEC & CELL BIOL,401 BARKER HALL,BERKELEY,CA 94720, USA.
NR 31
TC 168
Z9 184
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 511
EP 517
DI 10.1038/362511a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300044
PM 8464492
DA 2026-03-10
ER

PT J
AU GOZIN, M
   WEISMAN, A
   BENDAVID, Y
   MILSTEIN, D
AF GOZIN, M
   WEISMAN, A
   BENDAVID, Y
   MILSTEIN, D
TI ACTIVATION OF A CARBON-CARBON BOND IN SOLUTION BY TRANSITION-METAL INSERTION
SO NATURE
LA English
DT Article
ID c-c bonds; complexes; cleavage; hydrocarbons; elimination; alkanes; model
AB CLEAVAGE of carbon-carbon bonds by transition-metal-containing heterogeneous catalysts forms the basis of one of the most important industrial processes, the refining of petroleum to chemicals and fuels1. But the generally low product selectivity observed with heterogeneous systems is a significant drawback. For this reason, much effort has been devoted to developing transition-metal complexes that can be inserted into C-C bonds in homogeneous media, as such catalysts can operate under mild, easily controlled conditions and might offer high selectivity and reactivity. Metal insertion into C-H bonds is well known2,3-5, but, except in a few special cases2,6-12, C-C bonds are generally unreactive towards insertion of transition metals in solution. Here we report the selective activation of a simple C-C bond by a mononuclear rhodium complex in a neutral homogeneous medium (tetrahydrofuran solution). We are able to effect Rh insertion into a C-C bond in a diphosphinoxylene, in which this bond is favourably oriented towards the transition-metal centre. The competing reaction of insertion into C-H is suppressed by the use of an overpressure of H-2. We suggest that this approach might lead to a general strategy for C-C activation in homogeneous systems.
C1 WEIZMANN INST SCI,DEPT ORGAN CHEM,IL-76100 REHOVOT,ISRAEL.
C3 Weizmann Institute of Science
NR 24
TC 275
Z9 309
U1 0
U2 80
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 699
EP 701
DI 10.1038/364699a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700050
DA 2026-03-10
ER

PT J
AU JIN, S
   GRAEBNER, JE
   MCCORMACK, M
   TIEFEL, TH
   KATZ, A
   DAUTREMONTSMITH, WC
AF JIN, S
   GRAEBNER, JE
   MCCORMACK, M
   TIEFEL, TH
   KATZ, A
   DAUTREMONTSMITH, WC
TI SHAPING OF DIAMOND FILMS BY ETCHING WITH MOLTEN RARE-EARTH-METALS
SO NATURE
LA English
DT Article
AB DIAMOND films prepared by chemical vapour deposition (CVD) have received considerable attention because of their high thermal conductivity, optical transparency, hardness, inertness and semiconducting properties1,2. The control of film geometry (by thinning, polishing, patterning and shaping) is essential for most applications. Polishing by reaction with oxygen gas or ions usually results in pitting at grain boundaries3,4, and other techniques5-8 are generally slow. Thinning or polishing of single-crystal diamond9 and CVD films4,10 by high-temperature diffusional reaction with solid transition metals has been reported previously. But these approaches require either a hydrogen atmosphere9, which is undesirable industrially, or high pressures (200-3,000 p.s.i.) during the heat treatment4,10. We report here a method for shaping and thinning which does not suffer from these limitations. It involves the use of molten rare-earth metals such as cerium or lanthanum to etch away the diamond film surface. Substantial thinning and shaping can be achieved in just a few hours. We anticipate that this technique may open up new applications of diamond films in optics and biomedicine.
RP JIN, S (corresponding author), AT&T BELL LABS, MURRAY HILL, NJ 07974 USA.
NR 13
TC 39
Z9 44
U1 1
U2 13
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 822
EP 824
DI 10.1038/362822a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300049
DA 2026-03-10
ER

PT J
AU DOBERSTEIN, SK
   BAINES, IC
   WIEGAND, G
   KORN, ED
   POLLARD, TD
AF DOBERSTEIN, SK
   BAINES, IC
   WIEGAND, G
   KORN, ED
   POLLARD, TD
TI INHIBITION OF CONTRACTILE VACUOLE FUNCTION IN-VIVO BY ANTIBODIES AGAINST MYOSIN-I
SO NATURE
LA English
DT Article
AB MYOSIN-I is thought to supply the force for movement of cell membranes relative to actin filaments (reviewed in refs 1, 2), but confirmation of this hypothesis has been difficult because of the presence of multiple isoforms of myosin-I and other unconventional myosins in most cells3. We report here the first evidence that a myosin-I isoform is essential for a specific class of intracellular membrane movements in vivo. In Acanthamoeba, the contractile vacuole is an autonomous structure which fuses with the plasma membrane to control the water content of the cell. Because myosin-IC is the only myosin-I isoform concentrated in the contractile vacuole complex4,5 and a protein antigenically related to myosin-IC is located on or near the Dictyostelium (slime mould) contractile vacuole6, we thought this organelle might provide the best opportunity to demonstrate a relationship between myosin-I and membrane motility. Antibodies that inhibit the activity of Acanthamoeba myosin-IC in vitro interfere with expulsion of excess water by the contractile vacuole in vivo, leading to overfilling of this organelle and cell lysis. Myosin-IC may generate the force required to contract the vacuole and may also be involved in transfer of water to the contractile vacuole during refilling.
C1 JOHNS HOPKINS UNIV,SCH MED,DEPT MED,BALTIMORE,MD 21225.
   NHLBI,CELL BIOL LAB,BETHESDA,MD 20892.
C3 Johns Hopkins University; National Institutes of Health (NIH) - USA; NIH National Heart Lung & Blood Institute (NHLBI)
RP DOBERSTEIN, SK (corresponding author), JOHNS HOPKINS UNIV,SCH MED,DEPT CELL BIOL & ANAT,BALTIMORE,MD 21225, USA.
NR 27
TC 113
Z9 114
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 841
EP 843
DI 10.1038/365841a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100051
PM 8413668
DA 2026-03-10
ER

PT J
AU SCHRAUDER, M
   NAVON, O
AF SCHRAUDER, M
   NAVON, O
TI SOLID CARBON-DIOXIDE IN A NATURAL DIAMOND
SO NATURE
LA English
DT Article
ID infrared-absorption; mantle; system; pressure; co2; temperature; peridotite; equation; fluids; state
AB CARBON and hydrogen are only trace constituents of the Earth's mantle, yet carbon- and hydrogen-bearing fluids have an important effect on magma genesis, mantle rheology and mantle chemistry. Many mantle-derived rocks record interactions with such fluids, but direct samples of the fluids themselves are rare. Diamonds, owing to their robust nature, constitute effective sampling devices for such deep-seated fluids1; for example, carbonates and water have been found2,3 in fluid inclusions in fibrous diamonds4. In addition, CO2, H2O, CO, CH4, H-2 and N2 have been detected in gases released from diamonds by crushing5 or heating6,7, but their primary nature could not be confirmed beyond doubt1. Here we report the discovery of solid CO2 in a natural diamond.  Infrared spectroscopy indicates that the CO2 is presently at a pressure of 5 GPa (50 kbar), and must therefore have been trapped at even greater pressures in the hot mantle, corresponding to depths of about 220-270 km. At these pressures, free CO2 should react with olivine and pyroxene; thus, its survival indicates the presence at depth of an environment of different mineralogy such as a fully carbonated metasomatic vein, or a block of subducted sediments.
C1 UNIV VIENNA,INST GEOCHEM,A-1010 VIENNA,AUSTRIA.
C3 University of Vienna
RP SCHRAUDER, M (corresponding author), HEBREW UNIV JERUSALEM,INST EARTH SCI,IL-91904 JERUSALEM,ISRAEL.
NR 33
TC 136
Z9 144
U1 0
U2 35
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 42
EP 44
DI 10.1038/365042a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600048
DA 2026-03-10
ER

PT J
AU LOWE, G
   GOLD, GH
AF LOWE, G
   GOLD, GH
TI NONLINEAR AMPLIFICATION BY CALCIUM-DEPENDENT CHLORIDE CHANNELS IN OLFACTORY RECEPTOR-CELLS
SO NATURE
LA English
DT Article
ID sensitive adenylate-cyclase; 2nd messenger pathways; cyclic-nucleotides; odorant; cilia; activation; conductance; newt; rat; transduction
AB THE sense of smell is highly evolved in mammals, allowing discrimination between a vast number of odorants, with detection thresholds as low as 10(-17) M (ref. 1). Although several features of mammalian olfactory transduction have been revealed by biochemical and molecular biological studies2-11, the odorant-induced membrane current has remained elusive. In amphibians this current is mediated by cyclic-nucleotide-gated channels12-15, which depolarize the cell by Na+ and Ca+ influx16,17 and consequent Cl- efflux through Ca2+-dependent Cl- channels18,19. The Cl- current may be absent in mammals, however, because its proposed role is linked to the aquatic habitat of amphibians18. Here we show that the transduction current in rat olfactory receptor cells is initiated by cyclic-nucleotide-gated channels. The Cl- current is also present and endows the transduction current with a steep sigmoidal dependence on cyclic AMP concentration in both rat and in an amphibian, indicating a new function for the Cl- channel: nonlinear amplification of the transduction signal, whereby suprathreshold responses are boosted relative to basal transduction noise.
RP LOWE, G (corresponding author), MONELL CHEM SENSES CTR,3500 MARKET ST,PHILADELPHIA,PA 19104, USA.
NR 30
TC 285
Z9 313
U1 1
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 283
EP 286
DI 10.1038/366283a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500069
PM 8232590
DA 2026-03-10
ER

PT J
AU DRESSLER, GR
   WILKINSON, JE
   ROTHENPIELER, UW
   PATTERSON, LT
   WILLIAMSSIMONS, L
   WESTPHAL, H
AF DRESSLER, GR
   WILKINSON, JE
   ROTHENPIELER, UW
   PATTERSON, LT
   WILLIAMSSIMONS, L
   WESTPHAL, H
TI DEREGULATION OF PAX-2 EXPRESSION IN TRANSGENIC MICE GENERATES SEVERE KIDNEY ABNORMALITIES
SO NATURE
LA English
DT Article
ID promoter; gene
AB THE Pax genes comprise a family of transcription factors active in specific tissues during embryonic development and are associated with at least three developmental mutations in mouse and man1,2. In the developing kidney, Pax-2 is expressed in the induced mesenchyme, in the ureter epithelium, and in early epithelial structures derived from the mesenchyme3. Pax-2 expression is repressed upon terminal differentiation of the renal tubule epithelium, but persists in the undifferentiated epithelium of human Wilms' tumours4,5. We have produced a dominant gain-of-function mutation in transgenic mice by deregulating the expression of the mouse Pax-2 gene. The data obtained with four independently derived transgenic embryos and with one transgenic line demonstrate that deregulated Pax-2 expression results in histologically abnormal and dysfunctional renal epithelium with properties similar to congenital nephrotic syndrome. Thus, repression of Pax-2 is required for normal kidney development and persistent expression of Pax-2 may restrict the differentiation potential of renal epithelial cells.
C1 UNIV TENNESSEE, COLL VET MED, DEPT PATHOBIOL, KNOXVILLE, TN 37901 USA.
C3 University of Tennessee System; University of Tennessee Knoxville; UT Institute of Agriculture
RP DRESSLER, GR (corresponding author), NICHHD, MAMMALIAN GENES & DEV LAB, BETHESDA, MD 20892 USA.
NR 16
TC 263
Z9 287
U1 0
U2 0
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 65
EP 67
DI 10.1038/362065a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600061
PM 8383297
DA 2026-03-10
ER

PT J
AU FACELLI, JC
   GRANT, DM
AF FACELLI, JC
   GRANT, DM
TI DETERMINATION OF MOLECULAR SYMMETRY IN CRYSTALLINE NAPHTHALENE USING SOLID-STATE NMR
SO NATURE
LA English
DT Article
ID chemical-shift tensors; aromatic-compounds; c-13
AB DIFFRACTION techniques have shown that the crystal structure of naphthalene has a unit cell with C(i) symmetry1-7. These studies were unable, however, to resolve any departure of the molecular structure from the D2h symmetry observed in the gaseous state. We found recently8 that the solid-state C-13-nuclear magnetic resonance (NMR) chemical shifts for naphthalene exhibit the C(i) symmetry of the unit cell. If these chemical-shift data reflect structural distortions of the molecule, rather than simply intermolecular effects on the shifts owing to the C(i) symmetry of the environment of each molecule, one could assert that the NMR data are able to reveal structural information beyond the limits of the diffraction methods. Here we show that this is the case by performing ab initio quantum-mechanical calculations of the C-13 chemical shifts for naphthalene, and their derivatives, with respect to structural parameters. We find that intermolecular shift terms (which of necessity exhibit C(i) symmetry) can account for only about 30% of the maximum deviations from D2h symmetry; the remainder must therefore result from structural distortions of the molecules below D2h symmetry. This sensitivity of NMR chemical shifts to very small changes in molecular structure opens up the possibility of using solid-state NMR along with quantum-chemical methods to refine structural parameters obtained from diffraction methods.
C1 UNIV UTAH,UTAH SUPERCOMP INST,SALT LAKE CITY,UT 84112.
C3 Utah System of Higher Education; University of Utah
RP FACELLI, JC (corresponding author), UNIV UTAH,DEPT CHEM,SALT LAKE CITY,UT 84112, USA.
NR 16
TC 98
Z9 111
U1 0
U2 24
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 325
EP 327
DI 10.1038/365325a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600046
PM 8377823
DA 2026-03-10
ER

PT J
AU JABLONSKI, D
AF JABLONSKI, D
TI THE TROPICS AS A SOURCE OF EVOLUTIONARY NOVELTY THROUGH GEOLOGICAL TIME
SO NATURE
LA English
DT Article
ID diversity; sea
AB SPATIAL and temporal variations in biological diversity can be shaped by a variety of dynamical interactions between origination and extinction1-3. For this reason, the evolutionary basis of the latitudinal diversity gradient-with the tropics extraordinarily rich in species, higher taxa and evolutionary novelties-has been much debated4-8. High origination rates with the tropics operating as a diversity pump8-11, low extinction rates with the tropics operating as a diversity accumulator12-15, or some combination of the two16-18, have all been proposed to explain the wealth of higher taxa and morphological variety in low latitudes. Few historical data have been available, however, to test directly whether the tropics are 'a cradle or a museum'15,19. A new palaeontological analysis of post-Palaeozoic marine orders shows significantly more first appearances in tropical waters, whether defined latitudinally or biogeographically, than expected from sampling alone. This provides direct evidence that tropical regions have been a major source of evolutionary novelty, and not simply a refuge that accumulated diversity owing to low extinction rates.
RP JABLONSKI, D (corresponding author), UNIV CHICAGO, DEPT GEOPHYS SCI, 5734 S ELLIS AVE, CHICAGO, IL 60637 USA.
NR 43
TC 191
Z9 209
U1 0
U2 48
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 142
EP 144
DI 10.1038/364142a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700047
DA 2026-03-10
ER

PT J
AU PLEASURE, IT
   BLACK, MM
   KEEN, JH
AF PLEASURE, IT
   BLACK, MM
   KEEN, JH
TI VALOSIN-CONTAINING PROTEIN, VCP, IS A UBIQUITOUS CLATHRIN-BINDING PROTEIN
SO NATURE
LA English
DT Article
ID yeast; member; family; secretion; cdna
AB CLATHRIN is the structural protein of coated membranes involved in receptor-mediated endocytosis and aspects of Golgi sorting in eukaryotic cells. We have now detected a stoichiometric complex of clathrin with a novel protein of M(r) approximately 100,000 (100K) in lysates of different mammalian cells. Formation of the complex, which also includes the 70K heat-shock protein Hsc70, occurs within 15 min of synthesis. The 100K protein has been identified as valosin-containing protein (VCP; ref. 1), an early substrate for tyrosine phosphorylation on T-cell receptor activation2. Further, VCP is the mammalian homologue of yeast Cdc48p (ref. 3) and is a member of a larger gene family that includes putative ATP-binding proteins involved in vesicle transport and fusion4,5, 26S proteasome function6, regulation of the expression of human immunodeficiency virus7,8, and assembly of peroxisomes9. The association with clathrin and the morphological and catalytic similarity to the chaperonin proteins indicate that VCP may modulate protein-protein interactions in membrane transport processes.
C1 THOMAS JEFFERSON UNIV,DEPT PHARMACOL,233 S 10TH ST,PHILADELPHIA,PA 19107.
   THOMAS JEFFERSON UNIV,JEFFERSON CANC INST,PHILADELPHIA,PA 19107.
   TEMPLE UNIV,HLTH SCI CTR,SCH MED,DEPT ANAT & CELL BIOL,PHILADELPHIA,PA 19140.
C3 Thomas Jefferson University; Thomas Jefferson University; Pennsylvania Commonwealth System of Higher Education (PCSHE); Temple University
NR 19
TC 123
Z9 140
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 459
EP 462
DI 10.1038/365459a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300062
PM 8413590
DA 2026-03-10
ER

PT J
AU EDWARDS, CMH
   MORRIS, JD
   THIRLWALL, MF
AF EDWARDS, CMH
   MORRIS, JD
   THIRLWALL, MF
TI SEPARATING MANTLE FROM SLAB SIGNATURES IN ARC LAVAS USING B/BE AND RADIOGENIC ISOTOPE SYSTEMATICS
SO NATURE
LA English
DT Article
ID chemical characteristics; subduction zone; magmas; geochemistry; indonesia; transect; basalts; genesis; rocks; crust
AB AT convergent margins, tectonic processes juxtapose subducted slab, mantle wedge and the crust of the upper plate in a column beneath the overlying arc volcano. As each of these components is expected to be chemically heterogeneous, and as all may contribute to magma chemistry, identifying the different sources of arc magmas has been difficult. A working hypothesis has emerged, in which tholeiitic and calc-alkaline lavas in island arcs are partial melts of the mantle produced by fluxing of the wedge by hydrous fluids from the subducted slab1,2. Trace-element and radiogenic isotope ratios have been used to define the chemical characteristics of these sources but cannot be unequivocally identified with one source; by contrast, high B/Be and Be-10/Be-9 ratios in arc lavas uniquely identify the subduction component3,4, and thus separate chemical variability owing to recent subduction from that reflecting other causes. Here we combine B/Be with Sr, Nd and Pb isotope systematics of alkaline, calc-alkaline and tholeiitic lavas from Java and Flores, Indonesia, to constrain the isotopic composition of their mantle and subduction sources. The alkaline lavas always have low B/Be, from which we conclude that they are derived from mantle that has not been modified by recent subduction (in agreement with refs 5 and 6). We also show that the isotopic composition of the subducted component is relatively homogeneous along the length of the arc, suggesting that the subduction of Australian continental lithosphere in the east started too recently to have changed the nature of the subducted material at present beneath Flores.
C1 CARNEGIE INST WASHINGTON,DEPT TERR MAGNETISM,WASHINGTON,DC 20015.
   UNIV LONDON ROYAL HOLLOWAY & BEDFORD NEW COLL,DEPT GEOL,EGHAM TW20 0EX,SURREY,ENGLAND.
C3 Carnegie Institution for Science; University of London; Royal Holloway University London
NR 29
TC 85
Z9 100
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 530
EP 533
DI 10.1038/362530a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300050
DA 2026-03-10
ER

PT J
AU FIGDOR, MC
   STERN, CD
AF FIGDOR, MC
   STERN, CD
TI SEGMENTAL ORGANIZATION OF EMBRYONIC DIENCEPHALON
SO NATURE
LA English
DT Article
ID chick-embryo; neuronal development; nervous-system; somite cells; expression; mouse; forebrain; pattern; drosophila; hindbrain
AB THE diencephalon is a complex integration centre and intricate relay station of the vertebrate brain1-3. Its development involves the generation of great cellular diversity and neuronal specificity. We report here that it becomes organized in steps, through a stereotyped sequence of neuromeric subdivisions. Diencephalic neuromeres define four cellular domains (D1-D4) that can be followed throughout development, each unit contributing to a well defined part of the adult structural pattern. We propose that the segmental identity of each diencephalic unit is specified by a unique combination of genes4-13, maintained by polyclonal cell lineage restrictions. A comparison of vertebrate and arthropod development suggests that the basic principles that control anterior axial patterning and set up neuronal specificity in the embryonic central nervous system are highly conserved in evolution.
C1 UNIV OXFORD,DEPT HUMAN ANAT,S PARKS RD,OXFORD OX1 3QX,ENGLAND.
   INST HISTOL & EMBRYOL,A-1090 VIENNA,AUSTRIA.
C3 University of Oxford
FU Wellcome Trust Funding Source: Medline
NR 37
TC 372
Z9 383
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 630
EP 634
DI 10.1038/363630a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900057
PM 8510755
DA 2026-03-10
ER

PT J
AU GABRIEL, SE
   CLARKE, LL
   BOUCHER, RC
   STUTTS, MJ
AF GABRIEL, SE
   CLARKE, LL
   BOUCHER, RC
   STUTTS, MJ
TI CFTR AND OUTWARD RECTIFYING CHLORIDE CHANNELS ARE DISTINCT PROTEINS WITH A REGULATORY RELATIONSHIP
SO NATURE
LA English
DT Article
ID cystic-fibrosis gene; cl channels; kinase-c; conductance; cells; camp; expression; epithelia; disease
AB IN cystic fibrosis (CF), numerous epithelial cell functions are abnormal, including Cl- conductance, sodium absorption, mucin sulphation and enzyme secretion1-4. Although the CF gene product, the cystic fibrosis transmembrane conductance regulator (CFTR), functions as a small linear Cl- channel5-8, it is difficult to attribute such pleiotropic disease manifestations solely to a defect in Cl-conductance. This has led to speculation that CFTR regulates the activity of other proteins. One possible example is the protein kinase A activation of outward rectifying Cl- channels (ORCC), which is defective in membrane patches excised from CF cells9-16. Whether CFTR regulates the activity of an independent anion channel is debatable, because ORCC occur exclusively in excised membrane patches and could be an excision-induced molecular derivative of CFTR. 'Knockout' mice that lack CFTR17,18 provide a means to define the relationship between CFTR and ORCC. Here we report that ORCC are present in CFTR(-/-) mouse nasal epithelial cells and thus cannot be a derivative of the CFTR molecule. Also ORCC were regulated by protein kinase A in membrane patches from normal but not CFTR(-/-) cells. These observations are the first, to our knowledge definitive demonstration that CFTR regulates the activity of another protein.
RP GABRIEL, SE (corresponding author), UNIV N CAROLINA,DEPT MED,CHAPEL HILL,NC 27599, USA.
NR 32
TC 256
Z9 277
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 263
EP 266
DI 10.1038/363263a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600053
PM 7683773
DA 2026-03-10
ER

PT J
AU SCHERTLER, GFX
   VILLA, C
   HENDERSON, R
AF SCHERTLER, GFX
   VILLA, C
   HENDERSON, R
TI PROJECTION STRUCTURE OF RHODOPSIN
SO NATURE
LA English
DT Article
ID bovine rhodopsin; cysteine residue-110; purple membrane; resolution; bacteriorhodopsin; transducin; sequence
AB LIGHT absorption by the visual pigment rhodopsin1,2 triggers, through G-protein coupling, a cascade of events in the outer segment of the rod cell of the vertebrate retina that results in membrane hyperpolarization and nerve excitation3-5. Rhodopsin, which contains 348 amino acids6-8, has seven helices that cross the disk membrane 69 and its amino terminus is extracellular. A wealth of biochemical data is available for rhodopsin: 11-cis retinal is bound10 to lysine 296 in helix VII; glutamic acid 113 on helix III is the counterion to the protonated Schiffs base11,12; a disulphide bridge, cystine 110-187, connects helix III to the second extracellular loop e2 (refs 13, 14); the carboxy terminus has two palmitoylated cysteines forming a cytoplasmic loop i4 (ref. 15); three intracellular loops i2, i3 and i4 mediate activation of the heterotrimeric G protein transducin16,17; glutamic acid 135 and arginine 136 at the cytoplasmic end of helix III affect binding of transducin18. But to provide a framework to interpret these data, not only for rhodopsin but for other G-protein-coupled receptors, requires the structure to be determined. Here we present a projection map of rhodopsin showing the configuration of the helices.
RP SCHERTLER, GFX (corresponding author), MRC, MOLEC BIOL LAB, HILLS RD, CAMBRIDGE CB2 2QH, ENGLAND.
NR 27
TC 701
Z9 747
U1 0
U2 38
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 770
EP 772
DI 10.1038/362770a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000063
PM 8469290
DA 2026-03-10
ER

PT J
AU PEPYS, MB
   HAWKINS, PN
   BOOTH, DR
   VIGUSHIN, DM
   TENNENT, GA
   SOUTAR, AK
   TOTTY, N
   NGUYEN, O
   BLAKE, CCF
   TERRY, CJ
   FEEST, TG
   ZALIN, AM
   HSUAN, JJ
AF PEPYS, MB
   HAWKINS, PN
   BOOTH, DR
   VIGUSHIN, DM
   TENNENT, GA
   SOUTAR, AK
   TOTTY, N
   NGUYEN, O
   BLAKE, CCF
   TERRY, CJ
   FEEST, TG
   ZALIN, AM
   HSUAN, JJ
TI HUMAN LYSOZYME GENE-MUTATIONS CAUSE HEREDITARY SYSTEMIC AMYLOIDOSIS
SO NATURE
LA English
DT Article
ID dna
AB HEREDITARY non-neuropathic systemic amyloidosis (Ostertag-type)1 is a rare autosomal dominant disease in which amyloid deposition in the viscera is usually fatal by the fifth decade. In some families it is caused by mutations in the apolipoprotein AI gene2,3 but in two unrelated English families under our care the amyloid deposits did not contain apoAI, despite a report that this may have been the case in one of them4. Lysozyme is a ubiquitous bacteriolytic enzyme present in external secretions5 and in polymorphs and macrophages, but its physiological role is not always clear6. Here we report that in these two families, lysozyme is the amyloid fibril protein. Affected individuals are heterozygous for point mutations in the lysozyme gene that cause substitution of highly conserved residues, namely threonine for isoleucine at position 56 in one family, and histidine for aspartic acid at residue 67 in the other. Amyloid fibrils from one individual were composed of the full-length Thr-56 variant lysozyme molecule. To our knowledge, this is the first report of naturally occurring variants of human lysozyme and of lysozyme-associated disease. As the structures of human7 and hen egg-white lysozyme8 are known to atomic resolution and their folding and structure-function relationships have been exhaustively analysed, our observations should provide a powerful model for understanding amyloidogenesis.
C1 UNIV COLL & MIDDLESEX SCH MED,LUDWIG INST CANC RES,LONDON W1P 8BT,ENGLAND.
   WORDSLEY HOSP,STOURBRIDGE CY8 5QX,ENGLAND.
   HAMMERSMITH HOSP,ROYAL POSTGRAD MED SCH,MRC,LIPOPROT TEAM,LONDON W12 0NN,ENGLAND.
   UNIV OXFORD,MOLEC BIOPHYS LAB,OXFORD OX1 3QU,ENGLAND.
   SOUTHMEAD GEN HOSP,DEPT RENAL MED,BRISTOL BS10 5NB,AVON,ENGLAND.
C3 Ludwig Institute for Cancer Research; University of London; University College London; Imperial College London; University of Oxford; Southmead Hospital
RP PEPYS, MB (corresponding author), HAMMERSMITH HOSP,ROYAL POSTGRAD MED SCH,DEPT MED,IMMUNOL MED UNIT,LONDON W12 0NN,ENGLAND.
FU Wellcome Trust Funding Source: Medline
NR 31
TC 597
Z9 660
U1 1
U2 43
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 553
EP 557
DI 10.1038/362553a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300058
PM 8464497
DA 2026-03-10
ER

PT J
AU CORDES, JM
   ROMANI, RW
   LUNDGREN, SC
AF CORDES, JM
   ROMANI, RW
   LUNDGREN, SC
TI THE GUITAR NEBULA - A BOW SHOCK FROM A SLOW-SPIN, HIGH-VELOCITY NEUTRON-STAR
SO NATURE
LA English
DT Article
ID pulsar; g5.4-1.2
AB THE observable interactions of neutron stars with their local environment provide an opportunity for measuring the properties of both relativistic pulsar winds and the surrounding interstellar medium. Here we report the discovery of a prominent nebula produced by the motion of a high-velocity pulsar, PSR 2224 + 65, through partially neutral gas. The pulsar's transverse speed of greater than or similar to 800 km s-1 makes it arguably the fastest known star in the Galaxy and guarantees that it will ultimately escape the galactic potential well. A deep Halpha image reveals a bright head and a faint, limb-brightened 'body' whose variable width suggests that the ambient interstellar gas has density variations on length scales less than or similar to 0.1 pc. Thermalization of shock energy occurs at a rate of about 10(-2) times the pulsar's spindown loss rate. Our observations provide some insights into the likelihood of finding shocks around other pulsars and the use of nebulae to find high-velocity neutron stars either not acting as pulsars or with their radiation beamed away from the Earth.
C1 CORNELL UNIV,NATL ASTRON & IONOSPHERE CTR,ITHACA,NY 14853.
   STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305.
C3 Cornell University; Stanford University
RP CORDES, JM (corresponding author), CORNELL UNIV,DEPT ASTRON,ITHACA,NY 14853, USA.
NR 18
TC 216
Z9 234
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 133
EP 135
DI 10.1038/362133a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800050
DA 2026-03-10
ER

PT J
AU SPENGLER, D
   WAEBER, C
   PANTALONI, C
   HOLSBOER, F
   BOCKAERT, J
   SEEBURG, PH
   JOURNOT, L
AF SPENGLER, D
   WAEBER, C
   PANTALONI, C
   HOLSBOER, F
   BOCKAERT, J
   SEEBURG, PH
   JOURNOT, L
TI DIFFERENTIAL SIGNAL-TRANSDUCTION BY 5 SPLICE VARIANTS OF THE PACAP RECEPTOR
SO NATURE
LA English
DT Article
ID cyclase-activating polypeptide; metabotropic glutamate receptors; adenylate-cyclase; molecular-cloning; sympathetic neuroblasts; calcium release; binding-sites; rat-brain; expression; peptide
AB THE two forms of pituitary adenylyl cyclase-activating polypeptide (PACAP-27 and -38) are neuropeptides of the secretin/glucagon/vasoactive intestinal polypeptide/growth-hormone-releasing hormone family and regulate hormone release from the pituitary and adrenal gland1-3. They may also be involved in spermatogenesis4, and PACAP-38 potently stimulates neuritogenesis and survival of cultured rat sympathetic neuroblast5,6 and promotes neurite outgrowth of PC-12 cells7. The PACAP type-I receptor (found in hypothalamus, brain stem, pituitary, adrenal gland and testes), specific for PACAP, is positively coupled to adenylyl cyclase and phospholipase C. The recently cloned type II receptor does not discriminate between PACAP and vasoactive intestinal polypeptide and is coupled to only adenylyl cyclase8. Here we have used a new expression cloning strategy, based on the induction of a reporter gene by cyclic AMP, to isolate a complementary DNA encoding the type-I PACAP receptor. On transfection of this cDNA, both PACAP-27 and -38 stimulate adenylyl cyclase with similar EC50 values (50% effective concentration, 0.1-0.4 nM), whereas only PACAP-38 stimulates phospholipase C with high potency (EC50 = 15 nM). Four other splice variants were isolated with insertions at the C-terminal end of the third intracellular loop. Expression of these cDNAs revealed altered patterns of adenylyl cyclase and phospholipase C stimulation, suggesting a novel mechanism for fine tuning of signal transduction.
C1 CCIPE,CNRS,UPR 9023,RUE CARDONILLE,F-34094 MONTPELLIER 05,FRANCE.
   UNIV HEIDELBERG,ZMBH,MOLEC NEUROENDOCRINOL LAB,W-6900 HEIDELBERG 1,GERMANY.
   MAX PLANCK INST PSYCHIAT,INST CLIN,DEPT NEUROENDOCRINOL,W-8000 MUNICH 40,GERMANY.
C3 Centre National de la Recherche Scientifique (CNRS); Ruprecht Karls University Heidelberg; Max Planck Society
NR 33
TC 1151
Z9 1206
U1 0
U2 25
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 170
EP 175
DI 
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200051
PM 8396727
DA 2026-03-10
ER

PT J
AU HEINZ, DW
   BAASE, WA
   DAHLQUIST, FW
   MATTHEWS, BW
AF HEINZ, DW
   BAASE, WA
   DAHLQUIST, FW
   MATTHEWS, BW
TI HOW AMINO-ACID INSERTIONS ARE ALLOWED IN AN ALPHA-HELIX OF T4-LYSOZYME
SO NATURE
LA English
DT Article
ID protein stability curves; bacteriophage-t4 lysozyme; t4 lysozyme; sequences; accessibility; enzyme
AB STUDIES of extant protein sequences indicate that amino-acid insertions and deletions are preferentially located in loop regions1, which has traditionally been explained as the result of selection removing deleterious mutations within secondary structural elements from the population. But there is no a priori reason to discount the possibility that insertions within secondary structure could either be tolerated until compensatory mutations arise, or have effects that are propagated away from secondary structure into loops. Earlier studies have indicated that insertions are generally tolerated, although much less well within secondary structure elements than in loop regions2-8. Here we show that amino-acid insertions in an alpha-helix of T4 lysozyme can be accepted in two different ways. In some cases the inserted amino acids are accommodated within the helix, leading to the translocation of wild-type residues from the helix to the preceding loop. In other cases the insertion causes a 'looping-out' in the first or last turn of the helix. The individual structural responses seem to be dominated by the maintenance of the interface between the helix and the rest of the protein.
C1 UNIV OREGON,INST MOLEC BIOL,EUGENE,OR 97403.
   UNIV OREGON,HOWARD HUGHES MED INST,EUGENE,OR 97403.
   UNIV OREGON,DEPT PHYS,EUGENE,OR 97403.
   UNIV OREGON,DEPT CHEM,EUGENE,OR 97403.
C3 University of Oregon; Howard Hughes Medical Institute; University of Oregon; University of Oregon; University of Oregon
NR 28
TC 117
Z9 127
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 561
EP 564
DI 10.1038/361561a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400069
PM 8429913
DA 2026-03-10
ER

PT J
AU NORRIS, K
AF NORRIS, K
TI HERITABLE VARIATION IN A PLUMAGE INDICATOR OF VIABILITY IN MALE GREAT TITS PARUS-MAJOR
SO NATURE
LA English
DT Article
ID sexual selection; mating preferences; female choice; evolution; quality; coloration; handicap; fitness
AB THE idea that female birds choose mates on the basis of genetic quality is a contentious issue in sexual selection1,2 because empirical evidence is lacking3,4. Females mating with attractive males may obtain direct benefits such as high quality parental4-6 or breeding resources7, or indirect benefits such as offspring of high genotypic quality8-11. This debate could be resolved if the traits associated with attractiveness in males have a high heritability, and correlate with the viability of their offspring. Here I report the results of a cross-fostering experiment in great tits in which parents raised unrelated young. This showed that the plumage trait associated with attractiveness in males was heritable, and that the viability of male offspring was correlated with the plumage traits of their putative father. These results show that females mating with attractive male great tits realize an indirect fitness advantage.
RP NORRIS, K (corresponding author), UNIV OXFORD, EDWARD GREY INST, DEPT ZOOL, S PARKS RD, OXFORD OX1 3PS, ENGLAND.
NR 23
TC 220
Z9 241
U1 0
U2 64
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 537
EP 539
DI 10.1038/362537a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300052
DA 2026-03-10
ER

PT J
AU DAVIES, K
AF DAVIES, K
TI PROTECTION AND SUSCEPTIBILITY
SO NATURE
LA English
DT Article
NR 11
TC 0
Z9 0
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 478
EP 478
DI 10.1038/362478a0
PG 1
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400093
DA 2026-03-10
ER

PT J
AU ELKINS, JW
   THOMPSON, TM
   SWANSON, TH
   BUTLER, JH
   HALL, BD
   CUMMINGS, SO
   FISHER, DA
   RAFFO, AG
AF ELKINS, JW
   THOMPSON, TM
   SWANSON, TH
   BUTLER, JH
   HALL, BD
   CUMMINGS, SO
   FISHER, DA
   RAFFO, AG
TI DECREASE IN THE GROWTH-RATES OF ATMOSPHERIC CHLOROFLUOROCARBON-11 AND CHLOROFLUOROCARBON-12
SO NATURE
LA English
DT Article
ID trace gases; ozone; chlorine; stratosphere; latitudes; dioxide; ccl2f2; ccl3f; model
AB THE discovery of the Antarctic ozone hole1 in 1985 led to international efforts to reduce emissions of ozone-destroying chlorofluorocarbons2. These efforts culminated in the Montreal Protocol3 and its subsequent amendments, which called for the elimination of CFC production by 1996. Here we focus on CFC-11 (CCl3F) and CFC-12 (CCl2F2), which are used for refrigeration, air conditioning and the production of aerosols and foams4, and which together make up about half of the total abundance of stratospheric organic chlorine5. We report a significant recent decrease in the atmospheric growth rates of these two species, based on measurements spanning the past 15 years and latitudes ranging from 83-degrees-N to 90-degrees-S. This is consistent with CFC-producers' own estimates of reduced emissions6,7.  If the atmospheric growth rates of these two species continue to slow in line with predicted changes in industrial emissions, global atmospheric mixing ratios will reach a maximum before the turn of the century, and then begin to decline.
C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309.
   DUPONT CO INC,DIV SCI COMP,CENT RES & DEV,WILMINGTON,DE 19880.
   DUPONT CO INC,DIV FLUOROCHEM,WILMINGTON,DE 19898.
C3 National Oceanic Atmospheric Admin (NOAA) - USA; University of Colorado System; University of Colorado Boulder; DuPont; DuPont USA; DuPont; DuPont USA
RP ELKINS, JW (corresponding author), NOAA,CLIMATE MONITORING & DIAGNOST,BOULDER,CO 80303, USA.
NR 37
TC 221
Z9 230
U1 0
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 780
EP 783
DI 10.1038/364780a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100048
DA 2026-03-10
ER

PT J
AU BLAVETTE, D
   BOSTEL, A
   SARRAU, JM
   DECONIHOUT, B
   MENAND, A
AF BLAVETTE, D
   BOSTEL, A
   SARRAU, JM
   DECONIHOUT, B
   MENAND, A
TI AN ATOM-PROBE FOR 3-DIMENSIONAL TOMOGRAPHY
SO NATURE
LA English
DT Article
AB ELECTRIC-field-induced evaporation of ions from a needle-like surface, and their subsequent identification by time-of-flight mass spectrometry, forms the basis of the atom-probe technique1. This has proved to be a powerful analytical tool2,3, permitting the quantitative determination of material composition in a small selected region of the surface (depths of 1-5 nm) with single-layer resolution. Positional information for the atoms within each layer is lost, however. In contrast, the field-ion microscope3 provides atomic-resolution images of surfaces, but without information about the nature of the atoms. Several attempts have been made to combine these two techniques by extending the time-of-flight measurement into two dimensions, but they have been limited by their inability to identify all chemical species4 or to combine spatial and temporal information for multiple events5, especially for ions with very similar mass-to-charge ratios6. Here we make use of a recently developed7 multiple-impact detector to construct a position-sensitive atom probe with sufficiently high temporal resolution (of the order of 10 ns) to avoid these earlier problems; thus, reliable composition and position data can be obtained at the same time. We illustrate the performance of this instrument by imaging the three-dimensional distribution of chemical heterogeneities in a nickel-based alloy on a near-atomic scale.
RP BLAVETTE, D (corresponding author), FAC SCI & TECH MT ST AIGNAN,MICROSCOPIE ION LAB,CNRS,URA 808,BP 118,F-76134 MONT ST AIGNAN,FRANCE.
NR 10
TC 326
Z9 349
U1 1
U2 96
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 432
EP 435
DI 10.1038/363432a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800053
DA 2026-03-10
ER

PT J
AU SABOUNGI, ML
   FORTNER, J
   HOWELLS, WS
   PRICE, DL
AF SABOUNGI, ML
   FORTNER, J
   HOWELLS, WS
   PRICE, DL
TI DYNAMIC ENHANCEMENT OF CATION MIGRATION IN A ZINTL ALLOY BY POLYANION ROTATION
SO NATURE
LA English
DT Article
ID metal lead alloys; neutron-scattering; beta-nasn; cspb; kpb
AB ZINTL alloys are compounds of an alkali metal A with a polyvalent metal M in which transfer of an electron from A to M leads to bonding behaviour in the M- ions typical of elements one column to the right in the Periodic Table. For example, ASn and APb contain tetrahedral M4(4-) polyanions in both the crystalline and liquid phases1 whereas AAl alloys crystallize in tetrahedrally bonded networks typical of Group IV' elements2. These bonding patterns also determine the character of the disorder in the solid at high temperature. We have recently identified a plastic crystal phase in CsPb just below the melting point, in which the Pb-4(4-) polyanions undergo jump reorientations3; LiAl, in contrast, is metallic, with mobile Li+ ions4. Here we report unusual disordering behaviour in the Zintl alloy NaSn, in which both types of dynamic disorder appear: rapid reorientations of the Sn-4(4-) polyanions enhance jump migration of the Na+ cations by means of a 'paddle-wheel' effect. The two types of disorder are strongly coupled, so that only one disordering transition takes place as the melting point is approached.
C1 RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND.
C3 UK Research & Innovation (UKRI); Science & Technology Facilities Council (STFC); STFC Rutherford Appleton Laboratory
RP SABOUNGI, ML (corresponding author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA.
NR 23
TC 30
Z9 31
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 237
EP 239
DI 10.1038/365237a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100048
DA 2026-03-10
ER

PT J
AU SAMBROTTO, RN
   SAVIDGE, G
   ROBINSON, C
   BOYD, P
   TAKAHASHI, T
   KARL, DM
   LANGDON, C
   CHIPMAN, D
   MARRA, J
   CODISPOTI, L
AF SAMBROTTO, RN
   SAVIDGE, G
   ROBINSON, C
   BOYD, P
   TAKAHASHI, T
   KARL, DM
   LANGDON, C
   CHIPMAN, D
   MARRA, J
   CODISPOTI, L
TI ELEVATED CONSUMPTION OF CARBON RELATIVE TO NITROGEN IN THE SURFACE OCEAN
SO NATURE
LA English
DT Article
ID north-atlantic; variability; layer; flux; sea
AB UPTAKE of atmospheric CO2 by the ocean's 'biological pump' is driven by export of carbon from the euphotic zone to deeper waters1,2. As nitrate is a limiting nutrient in large regions of the ocean, measurements of nitrate uptake are often used to estimate the amount of carbon exported in this way3-6. This presupposes knowledge of the molar C:N ratio in the organic material exported from the upper waters, which is usually taken to be 6.6 (the Redfield ratio7,8). Recent studies have suggested, however, that the consumption ratio of C:N may deviate from this value in coastal waters9-11. Here we present time-series from both coastal waters and open-ocean sites which demonstrate that net organic carbon production greatly exceeded that predicted from nitrate consumption and the Redfield C:N ratio. We found a similar discrepancy in sections across broad regions of the North Atlantic during eutrophic periods. Our results suggest that extrapolating from nitrate consumption using the Redfield ratio leads to significant underestimates of organic carbon export from the euphotic zone.
C1 QUEENS UNIV BELFAST,SCH BIOL & BIOCHEM,MARINE BIOL STN,PORTAFERRY BT22 1PF,DOWN,NORTH IRELAND.
   UNIV WALES,SCH OCEAN SCI,MENAI BRIDGE LL59 5EY,GWYNEDD,WALES.
   UNIV HAWAII,SOEST,HONOLULU,HI 96822.
   MONTEREY BAY AQUARIUM,RES INST,PACIFIC GROVE,CA 93950.
C3 Queens University Belfast; University of Hawaii System; Monterey Bay Aquarium Research Institute
RP SAMBROTTO, RN (corresponding author), COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964, USA.
NR 29
TC 284
Z9 295
U1 1
U2 39
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 248
EP 250
DI 10.1038/363248a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600047
DA 2026-03-10
ER

PT J
AU LOTEM, A
AF LOTEM, A
TI LEARNING TO RECOGNIZE NESTLINGS IS MALADAPTIVE FOR CUCKOO CUCULUS-CANORUS HOSTS
SO NATURE
LA English
DT Article
ID brood parasitism; co-evolution; clutch-size; avian egg; discrimination; coevolution; birds
AB THE picture of a tiny passerine host feeding a huge cuckoo nestling challenges evolutionary biologists who explain animal behaviour as adaptive1-4. Cuckoo eggs sometimes resemble the eggs of the host, but nestlings of the common cuckoo, Cuculus canorus, look very different from the young of the host. The inability of the host to discriminate against such divergent nestlings is especially puzzling as some cuckoo hosts show a finely tuned discrimination ability between eggs5-8. Here I present a simple model to explain this paradox. The model shows that although learning to recognize eggs is adaptive, learning to recognize nestlings might not be. The mechanism of learned recognition, previously shown to maintain egg recognition, is unlikely to be adaptive for hosts like those of the common cuckoo, in which only the parasitic nestling remains in the nest. The reason that discrimination against parasite nestlings is not adaptive is that the cost of misimprinting (learning to recognize the parasite nestling as the parents' own) exceeds the benefit of correct learning. The model also explains why nestling discrimination is mostly found in host-parasite systems in which the parasite and the hosts' young are reared together1.
C1 TEL AVIV UNIV, FAC LIFE SCI, DEPT ZOOL, IL-69978 TEL AVIV, ISRAEL.
C3 Tel Aviv University
NR 21
TC 146
Z9 159
U1 1
U2 64
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 743
EP 745
DI 10.1038/362743a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000053
DA 2026-03-10
ER

PT J
AU CANO, RJ
   POINAR, HN
   PIENIAZEK, NJ
   ACRA, A
   POINAR, GO
AF CANO, RJ
   POINAR, HN
   PIENIAZEK, NJ
   ACRA, A
   POINAR, GO
TI AMPLIFICATION AND SEQUENCING OF DNA FROM A 120-135-MILLION-YEAR-OLD WEEVIL
SO NATURE
LA English
DT Article
ID extraction
AB DNA has been successfully isolated from both fossilized plant1 and animal tissues2-6. The oldest material, dated as 25-40 million years old (Tertiary), was obtained from amber-entombed been4,5 and termites6. Tissues from both these insects yielded DNA of good quality, which could be amplified by the polymerase chain reaction (PCR) and subsequently sequenced, including the genes encoding 18S ribosomal RNA5,6 and 16S rRNA6. We report here the extraction of DNA from a 120-135-million-year-old weevil (Nemonychidae, Coleoptera) found in Lebanese amber, PCR amplification of segments of the 18S rRNA gene and the internal transcribed spacer, and the corresponding nucleotide sequences of their 315- and 226-base-pair fragments, respectively. These sequences were used for preliminary phylogenetic analysis of the nemonychidae, sequence with three extant coleopterans: Lecontellus pinicola (Nemonychidae), Hypera brunneipennis (Curculionidae) and the mealworm Tenebrio molitor (Tenebrionidae), and two extant dipterans: the fruitfly Drosophila melanogaster (Drosophilidae) and mosquito Aedes albopictus (Culicidae) for the purpose of ascertaining the origin of the extracted and amplified DNA. The results revealed that the PCR-amplified material is that of the extinct nemonychid weevil. This represents the oldest fossil DNA ever extracted and sequenced, extending by 80 million years the age of any previously reported DNA4-6.
C1 CTR DIS CONTROL,PARASIT DIS BRANCH,ATLANTA,GA 30333.
   AMER UNIV BEIRUT,DEPT ENVIRONM HLTH,BEIRUT,LEBANON.
   UNIV CALIF BERKELEY,DEPT ENTOMOL SCI,BERKELEY,CA 94720.
C3 Centers for Disease Control & Prevention - USA; American University of Beirut; University of California System; University of California Berkeley
RP CANO, RJ (corresponding author), CALIF POLYTECH STATE UNIV SAN LUIS OBISPO,DEPT BIOL SCI,SAN LUIS OBISPO,CA 93407, USA.
NR 27
TC 197
Z9 225
U1 1
U2 46
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 536
EP 538
DI 10.1038/363536a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900047
PM 8505978
DA 2026-03-10
ER

PT J
AU OERLEMANS, J
AF OERLEMANS, J
TI EVALUATING THE ROLE OF CLIMATE COOLING IN ICEBERG PRODUCTION AND THE HEINRICH EVENTS
SO NATURE
LA English
DT Article
ID laurentide ice sheet; glacial cycles; model; sensitivity; growth
AB BOND et al.1 recently presented evidence for the frequent occurrence, in the Pleistocene epoch, of periods of massive iceberg discharge into the North Atlantic ocean ('Heinrich events'), each lasting a few thousand years. The cause of these events is uncertain, but one possibility1 is repeated advances of the Laurentide ice sheet during episodes of cooler climate. Here I examine this idea, using a model of the Laurentide ice sheet driven by orbitally forced variations in insolation, with and without three additional 3,000-yr-long cooling episodes, imposed just before the occurrence of the three most recent Heinrich events (H1, H2 and H3). In the model, the cooling event preceding H1 (when the climate was relatively warm and deglaciation was about to begin) led to increased calving, but those preceding H2 and H3 (which occurred during the last ice age, when the climate was very cold) led to reduced iceberg calving. It thus seems unlikely that the Heinrich events generally reflect a direct response of the Laurentide ice sheet to climate cooling.
RP OERLEMANS, J (corresponding author), UNIV UTRECHT, INST MARINE & ATMOSPHER RES, PRINCETONPLEIN 5, 3584 CC UTRECHT, NETHERLANDS.
NR 22
TC 22
Z9 22
U1 0
U2 13
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 783
EP 786
DI 10.1038/364783a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100049
DA 2026-03-10
ER

PT J
AU OSTFELD, RS
   CANHAM, CD
   PUGH, SR
AF OSTFELD, RS
   CANHAM, CD
   PUGH, SR
TI INTRINSIC DENSITY-DEPENDENT REGULATION OF VOLE POPULATIONS
SO NATURE
LA English
DT Article
ID animal populations; small mammals; cycles
AB CONSIDERABLE controversy exists over the role of density-dependent processes in controlling animal population size. In populations that fluctuate cyclically or erratically, for example many voles and insects1,2, theory predicts that either density-dependence is weak1,3, or that density-dependent responses lag behind density4-6. One key mechanism for lagged density-dependence is a delay in regeneration of food resources following heavy exploitation. Here we show that meadow vole (Microtus pennsylvanicus) populations respond immediately to high density by reducing breeding effort and hence population growth, disproving the hypothesis that density-dependence is weak. In addition, vole populations do not show a delay in growth following marked reduction in plant biomass (their source of food and cover). We conclude that intrinsic density-dependence processes tend to stabilize vole populations, and that cyclic dynamics are not caused by lagged effects of resource exploitation.
C1 BOSTON UNIV, COLL GEN STUDIES, BOSTON, MA 02215 USA.
C3 Boston University
RP OSTFELD, RS (corresponding author), INST ECOSYST STUDIES, BOX AB, MILLBROOK, NY 12545 USA.
NR 29
TC 88
Z9 95
U1 1
U2 28
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 259
EP 261
DI 10.1038/366259a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500061
PM 8232583
DA 2026-03-10
ER

PT J
AU STEINBOCK, O
   ZYKOV, V
   MULLER, SC
AF STEINBOCK, O
   ZYKOV, V
   MULLER, SC
TI CONTROL OF SPIRAL-WAVE DYNAMICS IN ACTIVE MEDIA BY PERIODIC MODULATION OF EXCITABILITY
SO NATURE
LA English
DT Article
ID chemical waves; systems; rotation; model
AB EXCITABLE media exhibit a wide variety of geometrically complex spatio-temporal patterns, perhaps the most striking of which are rotating spiral waves. Spiral waves have now been observed in many excitable systems, including heart muscle1, aggregating slime-mould cells2, retinae3, CO oxidation on platinum4 and oscillatory chemical systems such as the Belousov-Zhabotinsky (BZ) reaction5,6. In the last case, the spiral cores trace out circular or hypocycloidal trajectories, depending on the specific reaction conditions7-9. In addition, if the excitability of the BZ reaction is light-sensitive10-13, constant illumination has been shown to influence the dynamics of spiral waves14,15. Here we investigate the effect of illumination that is periodically modulated in time. We find that, for a single set of reaction conditions, the motion of the spiral cores can be forced to describe a wide range of open and closed hypocycloidal trajectories, in phase with the applied modulation frequency. Numerical simulations using a modified version of the Oregonator model16,17 of the BZ reaction reproduce this behaviour. We suggest that the modulation of excitability with weak external forces might be used as a means for controlling the dynamics of other excitable media.
C1 MOSCOW CONTROL SCI INST,MOSCOW,RUSSIA.
C3 V.A. Trapeznikov Institute of Control Sciences, Russian Academy of Sciences
RP STEINBOCK, O (corresponding author), MAX PLANCK INST MOLEK PHYSIOL,RHEINLANDDAMM 201,D-44139 DORTMUND 1,GERMANY.
NR 22
TC 309
Z9 326
U1 0
U2 45
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 322
EP 324
DI 10.1038/366322a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500041
DA 2026-03-10
ER

PT J
AU FERAT, JL
   MICHEL, F
AF FERAT, JL
   MICHEL, F
TI GROUP-II SELF-SPLICING INTRONS IN BACTERIA
SO NATURE
LA English
DT Article
ID dna binding-protein; escherichia-coli; purple bacteria; chloroplasts; sequences; origins
AB LIKE nuclear premessenger introns, group II self-splicing introns are excised from primary transcripts as branched molecules, containing a 2'-5' phosphodiester bond. For this reason, it is widely believed that the ribozyme (catalytic RNA) core of group II introns, or some evolutionarily related molecule, gave rise to the RNA components of the spliceosomal splicing machinery of the eukaryotic nucleus1. One difficulty with this hypothesis has been the restricted distribution of group II introns. Unlike group I self-splicing introns, which interrupt not only organelle primary transcripts, but also some bacterial and nuclear genes2-5, group II introns seemed to be confined to mitochondrial and chloroplast genomes (reviewed in ref. 6). We now report the discovery of group II introns both in cyanobacteria (the ancestors of chloroplasts7) and the gamma subdivision of purple bacteria, or proteobacteria8, whose alpha subdivision probably gave rise to mitochondria9. At least one of these introns actually self-splices in vitro.
RP FERAT, JL (corresponding author), CNRS,CTR GENET MOLEC,F-91190 GIF SUR YVETTE,FRANCE.
NR 26
TC 212
Z9 238
U1 0
U2 13
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 358
EP 361
DI 10.1038/364358a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000064
PM 7687328
DA 2026-03-10
ER

PT J
AU HOLLERBACH, R
   JONES, CA
AF HOLLERBACH, R
   JONES, CA
TI INFLUENCE OF THE EARTHS INNER-CORE ON GEOMAGNETIC FLUCTUATIONS AND REVERSALS
SO NATURE
LA English
DT Article
ID geodynamo
AB IN view of its relatively small size (one-third the radius of the outer core), many geodynamo models neglect the inner core entirely1, or otherwise treat it as a non-conducting insulator2,3. In a previous steady-state model4, we considered some effects of a finitely conducting inner core, in particular the resulting electromagnetic coupling between inner and outer core. Here we include a prescribed buoyancy force, which is geophysically more realistic, and also yields time-dependent rather than time-independent solutions. The field in the finitely conducting inner core does not then adjust instantaneously to the field in the outer core, but has a diffusive timescale of its own of a few thousand years. Rather large, rapid fluctuations in the outer core are then effectively averaged out by the inner core, producing a relatively stable external dipole field. We speculate that a geomagnetic reversal could only occur as a result of a particularly large fluctuation, large enough and lasting long enough to reverse the field throughout the inner core as well.
RP HOLLERBACH, R (corresponding author), UNIV EXETER,DEPT MATH,EXETER EX4 4QE,ENGLAND.
NR 17
TC 170
Z9 174
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 541
EP 543
DI 10.1038/365541a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100051
DA 2026-03-10
ER

PT J
AU SIEPMANN, JI
   KARABORNI, S
   SMIT, B
AF SIEPMANN, JI
   KARABORNI, S
   SMIT, B
TI SIMULATING THE CRITICAL-BEHAVIOR OF COMPLEX FLUIDS
SO NATURE
LA English
DT Article
ID phase-equilibria; chain molecules; gibbs ensemble; normal-alkanes; monte-carlo; membrane; scheme
AB ALTHOUGH the liquid-gas phase equilibria of simple fluids have been studied extensively since the seminal work of van der Waals, the properties of fluids with more complex molecular structures, such as polymers, present a less tractable problem both theoretically and experimentally. The phase behaviour of hydrocarbons is of particular importance for the petrochemical industry. But despite significant experimental and theoretical efforts, the phase diagrams of the straight-chain alkanes longer than decane (C-10) are known only partially, and even qualitative aspects such as the chain-length dependence of the critical properties are poorly understood. Until recently it was considered impossible to estimate the critical properties of such complex fluids using computer simulations. Here we report Monte Carlo simulations of the phase diagrams of alkanes with unbranched carbon chains as long as C48, up to the vicinity of the liquid-vapour critical points. Our calculations show that, in contrast to the traditional view, the critical density of the long-chain alkanes decreases rather than increases with carbon number. This work indicates that simulations can be used as an 'engineering tool' to estimate properties that are not readily accessible experimentally.
C1 SHELL INT RES MAATSCHAPPIJ BV,KONINKLIJKE SHELL LAB,POB 3003,1003 AA AMSTERDAM,NETHERLANDS.
C3 Royal Dutch Shell
NR 17
TC 453
Z9 494
U1 1
U2 60
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 330
EP 332
DI 10.1038/365330a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600048
DA 2026-03-10
ER

PT J
AU PUTILIN, SN
   ANTIPOV, EV
   CHMAISSEM, O
   MAREZIO, M
AF PUTILIN, SN
   ANTIPOV, EV
   CHMAISSEM, O
   MAREZIO, M
TI SUPERCONDUCTIVITY AT 94-K IN HGBA2CUO4+DELTA
SO NATURE
LA English
DT Article
ID high-temperature superconductors; system; la
AB FOLLOWING the discovery1 of high-transition-temperature (high-T(c)), superconductivity in doped La2CuO4 several families of related compounds have been discovered which have layers of CuO2 as the essential requirement for superconductivity: the highest transition temperatures so far have been found for thallium-bearing compounds2. Recently the mercury-bearing compound HgBa2RCu2O6+delta (Hg-1212) was synthesized3 (where R is a rare-earth element), with a structure similar to the thallium-bearing superconductor TlBa2CaCu2O7 (Tl-1212), which has one TlO layer and two CuO2 layers per unit cell, and a T(c) of 85 K (ref. 2). But in spite of its resemblance to Tl-1212, Hg-1212 was found not to be superconducting. Here we report the synthesis of the related compound HgBa2CuO4+delta (Hg-1201), with only one CuO2 layer per unit cell, and show that it is superconducting below 94 K. Its structure is similar to that of Tl-1201 (which has a T(c) of < 10 K)4, but its transition temperature is considerably higher. The availability of a material with high T(c) but only a single metal oxide (HgO) layer may be important for technological applications, as it seems that a smaller spacing between CuO2 planes leads to better superconducting properties in a magnetic field5.
C1 AT&T BELL LABS,MURRAY HILL,NJ 07974.
   UJF,CNRS,CRISTALLOG LAB,F-38042 GRENOBLE 09,FRANCE.
C3 Nokia Corporation; Nokia Bell Labs; AT&T; Centre National de la Recherche Scientifique (CNRS); Communaute Universite Grenoble Alpes; Universite Grenoble Alpes (UGA)
RP PUTILIN, SN (corresponding author), MOSCOW MV LOMONOSOV STATE UNIV,DEPT CHEM,MOSCOW 119899,RUSSIA.
NR 7
TC 962
Z9 1000
U1 2
U2 109
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 226
EP 228
DI 10.1038/362226a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600048
DA 2026-03-10
ER

PT J
AU DONNELLAN, A
   HAGER, BH
   KING, RW
AF DONNELLAN, A
   HAGER, BH
   KING, RW
TI DISCREPANCY BETWEEN GEOLOGICAL AND GEODETIC DEFORMATION RATES IN THE VENTURA BASIN
SO NATURE
LA English
DT Article
ID western transverse ranges; southern-california; earthquakes; kinematics; fault
AB SPACE geodesy provides a new tool for measuring neotectonic deformation which, when combined with geological and geophysical observations and models, can be used to infer rates and styles of deformation. In the Ventura basin region of southern California, the geodetically measured convergence rates of approximately 7-10 mm yr-1 (ref. 1) are significantly lower than the 20-25 mm yr-1 estimated from geological data2,3 . Here we investigate the possible implications of this discrepancy. It might be, for example, that temporal variations cause the short- and long-term convergence rates to differ. But if this were the case we would expect to observe the long-term rate by extending the geodetic measurements over a broader region, yet only 11+/-3 mm yr-1 of regional convergence is observed4. Our preferred explanation of the discrepancy is that the geological models require revision, and to this end we present two deformation models that satisfy both the geological and geodetic constraints. Our modelling suggests that the faults bounding the basin are locked at the surface, but are slipping at depths below approximately 2-5 km.
C1 MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139.
C3 Massachusetts Institute of Technology (MIT)
RP DONNELLAN, A (corresponding author), JET PROP LAB,PASADENA,CA 91109, USA.
NR 19
TC 59
Z9 62
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 333
EP 336
DI 10.1038/366333a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500045
DA 2026-03-10
ER

PT J
AU VALCARCEL, J
   SINGH, R
   ZAMORE, PD
   GREEN, MR
AF VALCARCEL, J
   SINGH, R
   ZAMORE, PD
   GREEN, MR
TI THE PROTEIN SEX-LETHAL ANTAGONIZES THE SPLICING FACTOR U2AF TO REGULATE ALTERNATIVE SPLICING OF TRANSFORMER PREMESSENGER RNA
SO NATURE
LA English
DT Article
ID drosophila-melanogaster; biochemical-characterization; auxiliary factor; gene; invitro; sequence; binding; site; differentiation; purification
AB SOMATIC sexual differentiation in Drosophila melanogaster involves a cascade of regulated splicing events1,2 and provides an attractive model system for the analysis of alternative splicing mechanisms. The protein Sex-lethal (SXl)3,4 activates a female-specific 3' splice site in the first intron of transformer (tra) pre-mRNA while repressing an alternative non-sex-specific site5-7. We have developed an in vitro system that recapitulates this regulation in a manner consistent with genetic, transfection and fly transformation studies4-8. Using this system, we have determined the molecular basis of the splice site switch. Here we show that Sxl inhibits splicing to the non-sex-specific (default) site by specifically binding to its polypyrimidine tract, blocking the binding of the essential splicing factor U2AF. This enables U2AF to activate the lower-affinity female-specific site. A splicing 'effector' domain present in U2AF but absent from Sxl accounts for the different activities of these two polypyrimidine-tract-binding proteins: addition of the U2AF effector domain to Sxl converts it from a splicing repressor to an activator and renders it unable to mediate splice-site switching.
RP VALCARCEL, J (corresponding author), UNIV MASSACHUSETTS, MED CTR, PROGRAM MOLEC MED, 373 PLANTAT ST, WORCESTER, MA 01605 USA.
NR 33
TC 294
Z9 340
U1 1
U2 9
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 171
EP 175
DI 10.1038/362171a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800064
PM 7680770
DA 2026-03-10
ER

PT J
AU SOLOMON, S
   SANDERS, RW
   GARCIA, RR
   KEYS, JG
AF SOLOMON, S
   SANDERS, RW
   GARCIA, RR
   KEYS, JG
TI INCREASED CHLORINE DIOXIDE OVER ANTARCTICA CAUSED BY VOLCANIC AEROSOLS FROM MOUNT-PINATUBO
SO NATURE
LA English
DT Article
ID heterogeneous chemistry; ozone destruction; oclo
AB THE annual springtime depletion of Antarctic ozone1 has been shown to be due to the action of chlorine species, activated by reactions occurring on the surfaces of polar stratospheric clouds (pSCS)1,2. Similar reactions may also take place on the surfaces of liquid sulphuric acid aerosols when the temperature is too high to permit the formation of PSCs3-4. Such processes may have been facilitated following the eruption of Mount Pinatubo in June 1991, when unprecedented amounts of sulphur compounds were injected into the stratosphere5. Here we present observations of Antarctic chlorine dioxide abundances in the austral autumn and winter of 1991 (when aerosol concentrations were at background levels) and 1992 (greatly enhanced aerosol concentrations). We find that in 1992, unlike 1991, chlorine dioxide levels increased dramatically in the autumn, when PSCs were extremely unlikely to have been present. Model results suggest that this was mainly caused by the direct activation of chlorine nitrate on the aerosol surfaces. The effect of the Pinatubo aerosols probably contributed to the unprecedented depth and areal extent of Antarctic ozone depletion in 1992.
C1 NATL CTR ATMOSPHER RES,BOULDER,CO 80307.
   NATL INST WATER & AIR RES,LAUDER,NEW ZEALAND.
C3 National Center Atmospheric Research (NCAR) - USA; Earth Sciences New Zealand; National Institute of Water & Atmospheric Research (NIWA) - New Zealand
RP SOLOMON, S (corresponding author), NOAA,AERON LAB,BOULDER,CO 80303, USA.
NR 21
TC 115
Z9 119
U1 1
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 245
EP 248
DI 10.1038/363245a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600046
DA 2026-03-10
ER

PT J
AU BERTRAND, P
   LALLIERVERGES, E
AF BERTRAND, P
   LALLIERVERGES, E
TI PAST SEDIMENTARY ORGANIC-MATTER ACCUMULATION AND DEGRADATION CONTROLLED BY PRODUCTIVITY
SO NATURE
LA English
DT Article
ID high-resolution; carbon cycle; yorkshire gb; geochemistry; ocean; rocks; bed
AB CHANGES in bottom-water oxygen concentration are commonly invoked to account for past changes in sedimentary organic carbon accumulation, as organic matter is more readily preserved in anoxic conditions1-5. On the other hand, upper-water productivity has been shown to be the main controlling factor for accumulation of organic matter in modern sediments6,7. It is therefore important to understand whether productivity significantly influenced accumulation patterns in the past, for example during the formation of petroleum source rocks. Here we present a study of a 150-Myr-old sequence containing short-term cycles in organic carbon content from the Kimmeridge Clay formation in Northern England. The lack of bioturbation and the fine-scale laminations throughout this section demonstrate that the sequence was deposited under continuously anoxic bottom-water conditions, so that oxic excursions cannot account for the cyclic accumulation pattern. We show that in this cycle, increased planktonic productivity appears to have caused both increased sedimentary accumulation of refractory organic material, and increased anaerobic degradation of metobolizable organic material. Thus, upper-water productivity should be considered as an important factor in controlling past as well as resent accumulation patterns.
C1 UNIV ORLEANS,CNRS,URA 724,F-45067 ORLEANS 2,FRANCE.
C3 Universite de Orleans; Centre National de la Recherche Scientifique (CNRS)
NR 17
TC 74
Z9 82
U1 0
U2 14
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 786
EP 788
DI 10.1038/364786a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100050
DA 2026-03-10
ER

PT J
AU PATEL, JS
   YOKOYAMA, H
AF PATEL, JS
   YOKOYAMA, H
TI CONTINUOUS ANCHORING TRANSITION IN LIQUID-CRYSTALS
SO NATURE
LA English
DT Article
ID surface; films
AB THE search for new ways of aligning liquid crystals1 is motivated by their potential for optical and optoelectronic device applications. Rubbing of surfaces coated with an 'aligning agent' can induce an orientational preference in adjacent liquid-crystal films. Most of these surface preparations produce strong anchoring, in which the alignment remains pinned to the surface-induced orientation. But it is expected that for weak interactions with the surface, anchoring transitions may be possible in which the liquid-crystal orientation can be changed continuously, as a function of temperature for example2. Here we show that an anchoring transition can be observed for liquid crystals in contact with fluoropolymers as aligning agents. We find that the phenomenon might be general, and suggest that it provides the possibility of controlling precisely the angle of liquid-crystal alignment, and a method of producing weak anchoring.
C1 ELECTROTECH LAB,TSUKUBA,IBARAKI 305,JAPAN.
C3 National Institute of Advanced Industrial Science & Technology (AIST)
RP PATEL, JS (corresponding author), BELLCORE,331 NEWMAN SPRINGS RD,RED BANK,NJ 07710, USA.
NR 11
TC 94
Z9 99
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 525
EP 527
DI 10.1038/362525a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300048
DA 2026-03-10
ER

PT J
AU MAMMANO, F
   ASHMORE, JF
AF MAMMANO, F
   ASHMORE, JF
TI REVERSE TRANSDUCTION MEASURED IN THE ISOLATED COCHLEA BY LASER MICHELSON INTERFEROMETRY
SO NATURE
LA English
DT Article
AB IT is thought that the sensitivity of mammalian hearing depends on amplification of the incoming sound within the cochlea by a select population of sensory cells, the outer hair cells. It has been suggested that these cells sense displacements and feedback forces which enhance the basilar membrane motion by reducing the inherent damping of the cochlear partition1-7. In support of this hypothesis, outer hair cells show membrane-potential-induced length changes1-3 at acoustic rates. This process has been termed 'reverse transduction'. For amplification, the forces should be large enough to move the basilar membrane. Using a displacement-sensitive interferometer8, we tested this hypothesis in an isolated cochlea while stimulating the outer hair cells with current passed across the partition. We show here that the cochlear partition distorts under the action of electrically driven hair cell length changes and produces place-specific vibration of the basilar membrane of a magnitude comparable to that observed near auditory threshold (about 1 nm). Such measurements supply direct evidence that cochlear amplification arises from the properties of the outer hair cell population.
C1 SCH MED SCI,DEPT PHYSIOL,UNIV WALK,BRISTOL BS8 1TD,ENGLAND.
C3 University of Bristol
FU Wellcome Trust Funding Source: Medline
NR 28
TC 173
Z9 187
U1 0
U2 17
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 838
EP 841
DI 10.1038/365838a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100050
PM 8413667
DA 2026-03-10
ER

PT J
AU ZHOU, O
   FLEMING, RM
   MURPHY, DW
   ROSSEINSKY, MJ
   RAMIREZ, AP
   VANDOVER, RB
   HADDON, RC
AF ZHOU, O
   FLEMING, RM
   MURPHY, DW
   ROSSEINSKY, MJ
   RAMIREZ, AP
   VANDOVER, RB
   HADDON, RC
TI INCREASED TRANSITION-TEMPERATURE IN SUPERCONDUCTING NA2CSC60 BY INTERCALATION OF AMMONIA
SO NATURE
LA English
DT Article
AB A WIDE variety of alkali-metal fullerides (A(x)C60) have been prepared, with stoichiometries varying between 1 less-than-or-equal-to x less-than-or-equal-to 11 (refs 1, 2). Most of the compounds with x = 3 are superconductors with unusually high transition temperatures (T(c)) which increase with the size of the face-centred cubic unit cell3. The increase in T(c) on lattice expansion is attributed to a decrease in the conduction band width, and therefore one ultimately expects a saturation or down-turn of T(c) followed by a metal-insulator transition. We have sought to explore this regime by expanding the A3C60 structure through intercalation of neutral molecules capable of solvating the A+ ions. Here we report that the reaction of ammonia with Na2CsC60 (T(c) = 10.5 K; lattice constant a = 14.132 angstrom) produces the compound (NH3)4Na2CsC60, which has an expanded unit cell (a = 14.473 angstrom) and an increased T(c) of 29.6 K. The structure contains the Na(NH3)4+ cation on the octahedral site.
C1 AT&T BELL LABS,600 MT AVE,MURRAY HILL,NJ 07974.
C3 AT&T; Nokia Corporation; Nokia Bell Labs
NR 14
TC 119
Z9 122
U1 0
U2 17
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 433
EP 435
DI 10.1038/362433a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400077
DA 2026-03-10
ER

PT J
AU WAGNER, JJ
   TERMAN, GW
   CHAVKIN, C
AF WAGNER, JJ
   TERMAN, GW
   CHAVKIN, C
TI ENDOGENOUS DYNORPHINS INHIBIT EXCITATORY NEUROTRANSMISSION AND BLOCK LTP INDUCTION IN THE HIPPOCAMPUS
SO NATURE
LA English
DT Article
ID guinea-pig; rat hippocampus; perforant path; mossy fibers; aged rats; receptor; peptides; memory; immunoreactivity; transmission
AB ALTHOUGH anatomical and neurochemical studies suggest that endogenous opioids act as neurotransmitters1-7, their roles in normal and pathophysiological regulation of synaptic transmission are not defined. Here we examine the actions of prodynorphin-derived opioid peptides in the guinea-pig hippocampus and show that physiological stimulation of the dynorphin-containing dentate granule cells can release endogenous dynorphins, which then activate kappa1 opioid receptors present in the molecular layer of the dentate gyrus. Activation of kappa1 receptors by either pharmacologically applied agonist or endogenously released peptide reduces excitatory transmission in the dentate gyrus, as shown by a reduction in the excitatory postsynaptic currents evoked by stimulation of the perforant path, a principal excitatory afferent. In addition, released dynorphin peptides were found to block the induction of long-term potentiation (LTP) at the granule cell-perforant path synapse. The results indicate that endogenous dynorphins function in this hippocampal circuit, as retrograde, inhibitory neurotransmitters.
C1 UNIV WASHINGTON,DEPT PHARMACOL,SJ-30,SEATTLE,WA 98195.
   UNIV WASHINGTON,DEPT ANESTHESIOL,SEATTLE,WA 98195.
C3 University of Washington; University of Washington Seattle; University of Washington; University of Washington Seattle
FU NIDA NIH HHS [R01 DA004123] Funding Source: Medline
NR 31
TC 241
Z9 261
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 451
EP 454
DI 10.1038/363451a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800059
PM 8099201
DA 2026-03-10
ER

PT J
AU HWANG, KC
   MAUZERALL, D
AF HWANG, KC
   MAUZERALL, D
TI PHOTOINDUCED ELECTRON-TRANSPORT ACROSS A LIPID BILAYER MEDIATED BY C70
SO NATURE
LA English
DT Article
ID fullerenes c60; membranes; carbon
AB ELECTRON transport across a membrane is central to photosynthesis, to mitochondrial respiration and to the design of molecular systems for solar energy conversion. Relatively few synthetic molecules, however, have been shown to facilitate transport of electrons across a lipid bilayer1-3. We report here that C70 can act as both a photosensitizer for electron transfer from a donor molecule and a mediator for electron transport across a lipid bilayer membrane. The steady-state photocurrent density obtained from the C70-bilayer system is about 40 times higher, at comparable light intensities, than that of the carotene-porphyrin-quinone system2, previously the most efficient artificial system. The C70-bilayer system has a quantum yield of about 0.04, while the stability (tens of minutes) and turnover number (electrons transported per C70 before decay) of 10(3) are one to three orders of magnitude greater than those of other systems1-3. We anticipate that other higher fullerenes may also provide the basis for efficient transmembrane electron-transport systems.
RP HWANG, KC (corresponding author), ROCKEFELLER UNIV,1230 YORK AVE,NEW YORK,NY 10021, USA.
NR 23
TC 161
Z9 176
U1 1
U2 27
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 138
EP 140
DI 10.1038/361138a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600053
PM 8421519
DA 2026-03-10
ER

PT J
AU DAVIES, GJ
   DODSON, GG
   HUBBARD, RE
   TOLLEY, SP
   DAUTER, Z
   WILSON, KS
   HJORT, C
   MIKKELSEN, JM
   RASMUSSEN, G
   SCHULEIN, M
AF DAVIES, GJ
   DODSON, GG
   HUBBARD, RE
   TOLLEY, SP
   DAUTER, Z
   WILSON, KS
   HJORT, C
   MIKKELSEN, JM
   RASMUSSEN, G
   SCHULEIN, M
TI STRUCTURE AND FUNCTION OF ENDOGLUCANASE-V
SO NATURE
LA English
DT Article
ID 3-dimensional structure; protein structures; cellulases; refinement
AB CELLULOSE is the major polysaccharide component of plant cell walls and is the most abundant organic compound on the planet. A number of bacterial1 and fungal2 organisms can use cellulose as a food source, possessing cellulases (cellobiohydrolases and endoglucanases) that can catalyse the hydrolysis of the beta-(1,4) glycosidic bonds. They can be classified into seven distinct families3. The three-dimensional structures of members of two of these families are known4,5. Here we report the structure of a third cellulase, endoglucanase V, whose sequence is not represented in any of the above families. The enzyme is structurally distinct from the previously determined cellulases but is similar to a recently characterized plant defence protein6. The active site region resembles that of lysozyme, despite the lack of structural similarity between these two enzymes.
C1 DESY,EMBL,HAMBURG OUTSTN,W-2000 HAMBURG 52,GERMANY.
   NOVO NORDISK AS,DK-2880 BAGSVAERD,DENMARK.
C3 European Molecular Biology Laboratory (EMBL); Helmholtz Association; Deutsches Elektronen-Synchrotron (DESY); Novo Nordisk
RP DAVIES, GJ (corresponding author), UNIV YORK,DEPT CHEM,YORK YO1 5DD,N YORKSHIRE,ENGLAND.
NR 20
TC 130
Z9 138
U1 1
U2 19
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 362
EP 364
DI 10.1038/365362a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600059
PM 8377830
DA 2026-03-10
ER

PT J
AU CHAPPELLAZ, J
   BLUNIER, T
   RAYNAUD, D
   BARNOLA, JM
   SCHWANDER, J
   STAUFFER, B
AF CHAPPELLAZ, J
   BLUNIER, T
   RAYNAUD, D
   BARNOLA, JM
   SCHWANDER, J
   STAUFFER, B
TI SYNCHRONOUS CHANGES IN ATMOSPHERIC CH4 AND GREENLAND CLIMATE BETWEEN 40-KYR AND 8-KYR BP
SO NATURE
LA English
DT Article
ID north-atlantic ocean; vostok ice core; methane
AB ICE-CORE reconstructions of atmospheric methane concentrations for the past 220 kyr have revealed large variations associated with different climatic periods1-4. But the phase relationship between climate and methane has been uncertain because of dating uncertainties and the coarse sampling interval of available methane records. Here we present a high-resolution record of atmospheric methane from 40 to 8 kyr ago from the GRIP ice core in Greenland. Our improved resolution and dating allow us to conclude that the large changes in atmospheric methane concentration during the last deglaciation were in phase (+/-200 years) with the variations in Greenland climate. Our results confirm the previous observation3 that methane increased to Holocene levels when much of the Northern wetlands was still ice-covered, lending support to the suggestion3 that low-latitude wetlands were responsible for the observed changes. We observe oscillations in methane concentration associated with the warm periods (interstadials) that occurred throughout the glacial period5, suggesting that the interstadials were at least hemispheric in their extent. We propose that variations in the hydrological cycle at low latitudes may be responsible for the variations in both methane and Greenland temperature during the interstadials.
C1 INST PHYS,CH-3012 BERN,SWITZERLAND.
RP CHAPPELLAZ, J (corresponding author), LAB GLACIOL & GEOPHYS ENVIRONN,BP 96,F-38402 ST MARTIN DHERES,FRANCE.
NR 25
TC 327
Z9 373
U1 0
U2 51
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 443
EP 445
DI 10.1038/366443a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800057
DA 2026-03-10
ER

PT J
AU CLOZEL, M
   BREU, V
   BURRI, K
   CASSAL, JM
   FISCHLI, W
   GRAY, GA
   HIRTH, G
   LOFFLER, BM
   MULLER, M
   NEIDHART, W
   RAMUZ, H
AF CLOZEL, M
   BREU, V
   BURRI, K
   CASSAL, JM
   FISCHLI, W
   GRAY, GA
   HIRTH, G
   LOFFLER, BM
   MULLER, M
   NEIDHART, W
   RAMUZ, H
TI PATHOPHYSIOLOGICAL ROLE OF ENDOTHELIN REVEALED BY THE 1ST ORALLY-ACTIVE ENDOTHELIN RECEPTOR ANTAGONIST
SO NATURE
LA English
DT Article
ID subarachnoid hemorrhage; coronary-artery; smooth-muscle; blood-flow; rats; cells; vasodilation; mechanism; cloning; subtype
AB SINCE its discovery1, endothelin-1 has attracted considerable scientific interest because of its extremely potent and long-lasting vaso-constrictor effect and its binding to G-protein-coupled receptors2. Plasma concentrations of endothelin-1 are low3 and its release by endothelial cells is polarized towards the basolateral side4,5, suggesting that it is a paracrine factor and not a hormone. Consequently, the effect of injected endothelin-1 may not reflect the effect of endogenous endothelin-1. In contrast, blockade of the action of endogenous endothelin-1 using receptor antagonists should be a valuable means of investigating its physiological and pathological effects. We report here evidence for the pathophysiological role of endothelin-1 as brought by the first synthetic orally active non-peptide antagonist of endothelin receptors, Ro 46-2005.
RP CLOZEL, M (corresponding author), F HOFFMANN LA ROCHE & CO LTD,PRECLIN RES,DIV PHARMA,GRENZACHERSTR 124,CH-4002 BASEL,SWITZERLAND.
NR 31
TC 507
Z9 553
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 759
EP 761
DI 10.1038/365759a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200065
PM 8413655
DA 2026-03-10
ER

PT J
AU PETERS, LL
   ANDREWS, NC
   EICHER, EM
   DAVIDSON, MB
   ORKIN, SH
   LUX, SE
AF PETERS, LL
   ANDREWS, NC
   EICHER, EM
   DAVIDSON, MB
   ORKIN, SH
   LUX, SE
TI MOUSE MICROCYTIC ANEMIA CAUSED BY A DEFECT IN THE GENE ENCODING THE GLOBIN ENHANCER-BINDING PROTEIN NF-E2
SO NATURE
LA English
DT Article
ID dominant control region; messenger-rna; alpha-globin; cells; iron
AB THE nuclear DNA-binding protein NF-E2 is thought to mediate the powerful erythroid enhancer activity of the alpha and beta-globin locus control regions1-4 and participates in the control of genes encoding two enzymes of haem biosynthesis (porphobilinogen deaminase and ferrochelatase)1,5 The major component of NF-E2 is a 45K polypeptide (designated p45 NF-E2) that belongs to the basic region-leucine zipper family of transcription factors6. This subunit of NF-E2 is specifically expressed in haematopoietic progenitor cells and differentiated cells of the erythroid, megakaryocyte and mast cell lineages6. The gene encoding p45 NF-E2 (murine gene Nfe2) has been mapped to mouse chromosome 15 near the mutation microcytosis (mk). Homozygous mk mice have severe hypochromic microcytic anaemia as a result of decreased globin synthesis and defects in intestinal and erythroid iron absorption. Here we investigate whether the mk mutation lies within Nfe2 by characterizing the p45 NF-E2 gene and determining its DNA sequence in wild-type and mk alleles. The mk allele carries a missense mutation that causes substitution of valine by alanine at amino acid 173 of the p45 NF-E2 protein. Expression of p45 NF-E2 messenger RNA was detected in erythroid tissues of normal mice and in the duodenum of normal and severely anaemic beta-thalassaemic (Hbb(d-th3)/Hbb(d-th3)) mice. We propose that the mk mutation results in an impaired form of NF-E2 which fails to regulate both globin production and iron metabolism properly.
C1 CHILDRENS HOSP MED CTR, DIV HEMATOL ONCOL, BOSTON, MA 02115 USA.
   HARVARD UNIV, SCH MED, DANA FARBER CANC INST, DEPT PEDIAT, BOSTON, MA 02115 USA.
   JACKSON LAB, BAR HARBOR, ME 04609 USA.
   HARVARD UNIV, SCH MED, HOWARD HUGHES MED INST, BOSTON, MA 02115 USA.
C3 Harvard University; Harvard University Medical Affiliates; Boston Children's Hospital; Harvard University; Harvard University Medical Affiliates; Dana-Farber Cancer Institute; Harvard Medical School; Jackson Laboratory; Harvard University; Harvard Medical School; Howard Hughes Medical Institute
NR 23
TC 60
Z9 61
U1 0
U2 1
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 768
EP 770
DI 10.1038/362768a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000062
PM 8469289
DA 2026-03-10
ER

PT J
AU OGELMAN, H
   FINLEY, JP
   ZIMMERMANN, HU
AF OGELMAN, H
   FINLEY, JP
   ZIMMERMANN, HU
TI PULSED X-RAYS FROM THE VELA PULSAR
SO NATURE
LA English
DT Article
ID radio pulsars; upper limits; neutron stars; cos-b; emission; psr-0833-45; radiation
AB THE Vela pulsar, PSR0833-45, is a young (10(4) yr) nearby neutron star emitting pulsed radiation in radio, optical and gamma-ray bands1-5. Soft X-ray imaging by the Einstein6 and Exosat7 observatories has revealed a point-like source, at the position of the pulsar, embedded in a compact nebula approximately 2 arcmin in diameter, but the search for pulsed X-ray emission has proved difficult. There were claims in 1973 of a positive detection8,9 but subsequent observations have failed to confirm them6,10. Here we report an unambiguous detection, by means of the Rosat satellite11, of pulsed X-ray emission from the Vela pulsar, and thus put this long-standing enigma to rest. The pulsed signal is soft, appearing mainly at energies <1 keV. The Rosat observations resolve the two sources of emission, and show that the point-like emission centred on the pulsar is soft, whereas the emission from the compact nebula is hard. Despite the common prejudice that it is the archetypal young pulsar embedded in a supernova remnant, these observations show that Vela more closely resembles older (10(5) yr) pulsars.
C1 MAX PLANCK INST EXTRATERRESTR PHYS,W-8046 GARCHING,GERMANY.
C3 Max Planck Society
RP OGELMAN, H (corresponding author), UNIV WISCONSIN,DEPT PHYS,1150 UNIV AVE,MADISON,WI 53706, USA.
NR 25
TC 133
Z9 133
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 136
EP 138
DI 10.1038/361136a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600052
DA 2026-03-10
ER

PT J
AU JAMES, PA
   PUXLEY, PJ
AF JAMES, PA
   PUXLEY, PJ
TI A MEASUREMENT OF THE OPTICAL DEPTH THROUGH A GALAXY DISK
SO NATURE
LA English
DT Article
ID ngc-3314; dust
AB SEVERAL recent papers1-3 have refocused attention on the question of the degree of dust obscuration (or optical depth) of the disks of spiral galaxies. The traditional view, based on the early statistical studies of Holmberg4 and de Vaucouleurs5, is that the disks are largely transparent, whereas Disney et al.1 and Valentijn2 have recently argued in favour of substantial optical depths. In an attempt to resolve this issue, White and Keel3 measured the broad-band colours of an overlapping galaxy pair, to determine directly the optical depth of the foreground galaxy; however, using this method it was not possible to separate unambiguously the contributions from the two galaxies. Individual emission lines, on the other hand, are completely separated if the redshift difference between the two galaxies is large enough, as in the pair studied here, offering a means of removing the source ambiguity. By comparing the Halpha/Hbeta ratios for the H II regions in the background galaxy with those in isolated spiral galaxies, and exploiting the wavelength dependence of extinction by dust, we find significant optical depths along three lines of sight through the foreground galaxy.
RP JAMES, PA (corresponding author), ROYAL OBSERV,BLACKFORD HILL,EDINBURGH EH9 3HJ,MIDLOTHIAN,SCOTLAND.
NR 14
TC 24
Z9 25
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 240
EP 242
DI 10.1038/363240a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600043
DA 2026-03-10
ER

PT J
AU WALSTEDT, RE
   MURPHY, DW
   ROSSEINSKY, M
AF WALSTEDT, RE
   MURPHY, DW
   ROSSEINSKY, M
TI STRUCTURAL DISTORTION IN RB3C60 REVEALED BY RB-87 NMR
SO NATURE
LA English
DT Article
ID superconductivity; transition; k3c60; c60
AB INTEREST in the alkali-intercalated A(x)C60 fullerides (where A is an alkali metal and x = 2, 3, 4, 6)1,2 has been greatly enhanced by the discovery of a family of superconducting phases for x = 3 with transition temperatures (T(c)s) that are exceeded only by the copper oxide materials3-9. An early structure refinement5 identified K3C60 as a face-centred-cubic (f.c.c.) intercalation phase with two tetrahedral (T) and one octahedral (O) potassium ion per C60. The other superconducting A3C60 systems are isostructural7. Here we report Rb-87 NMR studies of Rb3C60 which show the expected T:O ratio of 2:1 at 440 K. Below 370 K, however, an additional resonance appears; spin-echo double-resonance NMR experiments11,12 show that this arises from a second type of tetrahedral Rb+ site (T'). Thus the bulk of this material has a local symmetry lower than that of the f.c.c. structure derived from X-ray refinements. Models that could account for this include a rotational orientation of C60 that places a C5 ring adjacent to the T' Rb+ ions. Alternatively, the symmetry lowering might be due to a Jahn-Teller distortion on C60(3-), carrier-density modulation or Rb+ clustering. Each of these models could lead to a degree of charge localization and consequent reduction in the density of states and hence in T(c).
RP WALSTEDT, RE (corresponding author), AT&T BELL LABS,DIV RES,600 MT AVE,MURRAY HILL,NJ 07974, USA.
NR 15
TC 83
Z9 83
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 611
EP 613
DI 10.1038/362611a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800039
DA 2026-03-10
ER

PT J
AU SOMMERFELD, RA
   MOSIER, AR
   MUSSELMAN, RC
AF SOMMERFELD, RA
   MOSIER, AR
   MUSSELMAN, RC
TI CO2, CH4 AND N2O FLUX THROUGH A WYOMING SNOWPACK AND IMPLICATIONS FOR GLOBAL BUDGETS
SO NATURE
LA English
DT Article
ID carbon-dioxide; nitrous-oxide; methane; soils
AB INCREASING atmospheric concentrations of the three main greenhouse gases-carbon dioxide, methane, and nitrous oxide-account for about 70% of anticipated global warming1, but the production consumption budgets are not balanced for any of these gases2. Snow can cover between 44 and 53% of the land area of the Northern Hemisphere3 and may be several metres deep in alpine and sub-alpine regions for more than half the year. Most trace-gas budgets assume that trace-gas exchange stops when soil is snow covered or soil temperatures drop to approximately 0-degrees-C (refs 4, 5). Thus alpine and sub-alpine soils are generally considered to be net sinks for atmospheric CO2. Some reports6,7, however, suggest that soil microorganisms beneath the snow continue to respire at temperatures close to 0-degrees-C. Here we present evidence that the soils under alpine and sub-alpine snowpacks emit CO2 and N2O and take up atmospheric CH4 throughout the snow-covered period. These fluxes represent an important part of the annual trace-gas budget for these ecosystems.
C1 USDA ARS,FT COLLINS,CO 80522.
C3 United States Department of Agriculture (USDA)
RP SOMMERFELD, RA (corresponding author), US FOREST SERV,240 W PROSPECT RD,FT COLLINS,CO 80526, USA.
NR 23
TC 378
Z9 443
U1 1
U2 135
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 140
EP 142
DI 10.1038/361140a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600054
DA 2026-03-10
ER

PT J
AU MANABE, S
   STOUFFER, RJ
AF MANABE, S
   STOUFFER, RJ
TI CENTURY-SCALE EFFECTS OF INCREASED ATMOSPHERIC CO2 ON THE OCEAN-ATMOSPHERE SYSTEM
SO NATURE
LA English
DT Article
ID interhemispheric asymmetry; climate response; model
AB SEVERAL studies have addressed the likely effects of CO2-induced climate change over the coming decades1-10, but the longer-term effects have received less attention. Yet these effects could be very significant, as persistent increases in global mean temperatures may ultimately influence the large-scale processes in the coupled ocean-atmosphere system that are thought to play a central part in determining global climate. The thermohaline circulation is one such process - Broecker has argued11 that it may have undergone abrupt changes in response to rising temperatures and ice-sheet melting at the end of the last glacial period. Here we use a coupled ocean-atmosphere climate model to study the evolution of the world's climate over the next few centuries, driven by doubling and quadrupling of the concentration of atmospheric CO2. We find that the global mean surface air temperature increases by about 3.5 and 7-degrees-C, respectively, over 500 years, and that sea-level rise owing to thermal expansion alone is about 1 and 2 m respectively (ice-sheet melting could make these values much larger). The thermal and dynamical structure of the oceans changes markedly in the quadrupled-CO2 climate - in particular, the ocean settles into a new stable state in which the thermohaline circulation has ceased entirely and the thermocline deepens substantially. These changes prevent the ventilation of the deep ocean and could have a profound impact on the carbon cycle and biogeochemistry of the coupled system.
RP MANABE, S (corresponding author), PRINCETON UNIV, NOAA, GEOPHYS FLUID DYNAM LAB, POB 308, PRINCETON, NJ 08542 USA.
NR 16
TC 405
Z9 449
U1 0
U2 90
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 215
EP 218
DI 10.1038/364215a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300049
DA 2026-03-10
ER

PT J
AU ATTALI, B
   GUILLEMARE, E
   LESAGE, F
   HONORE, E
   ROMEY, G
   LAZDUNSKI, M
   BARHANIN, J
AF ATTALI, B
   GUILLEMARE, E
   LESAGE, F
   HONORE, E
   ROMEY, G
   LAZDUNSKI, M
   BARHANIN, J
TI THE PROTEIN ISK IS A DUAL ACTIVATOR OF K+ AND CL- CHANNELS
SO NATURE
LA English
DT Article
AB THE protein IsK (M(r) 14,500) is present in epithelial cells1, heart2,3, uterus4 and lymphocytes5 and induces slowly activating K+ currents when expressed in Xenopus oocytes1. The finding that mutations of its single transmembrane segment altered channel gating6 or selectivity7 has suggested that IsK is a channel-forming protein. But IsK does not exhibit the K+ channel hallmarks8 (a conserved K+ selective pore (H5) flanked by either six9-11 or two 12,13 membrane-spanning regions). Here we report that IsK expression in Xenopus oocytes also induces a Cl- selective current very similar to the Cl- current produced by phospholemman expression14  and wit h biophysical, pharmacological and regulation characteristics very different from those of the IsK-induced K+ channel activity. IsK mutagenesis identifies amino- and carboxy-terminal domains as critical for the induction of Cl- and K+ channel activities, respectively. Our data lead to a model in which the IsK protein (now called IsK, Cl) acts as a potent activator of endogenous and otherwise silent K+ or Cl- channels.
C1 SOPHIA ANTIPOLIS,CNRS,INST PHARMACOL MOLEC & CELLULAIRE,660 ROUTE LUCIOLES,F-06560 VALBONNE,FRANCE.
C3 Centre National de la Recherche Scientifique (CNRS)
NR 22
TC 128
Z9 133
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 850
EP 852
DI 10.1038/365850a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100054
PM 8413671
DA 2026-03-10
ER

PT J
AU KEMP, AES
   BALDAUF, JG
AF KEMP, AES
   BALDAUF, JG
TI VAST NEOGENE LAMINATED DIATOM MAT DEPOSITS FROM THE EASTERN EQUATORIAL PACIFIC-OCEAN
SO NATURE
LA English
DT Article
ID events
AB THE eastern equatorial Pacific upwelling region is responsible for up to 50% of global 'new' production1 and is regarded as a barometer of ocean change. Here we report evidence, from several sediment cores in the region, for repeated episodes of increased equatorial primary production between 15 and 4.4 million years ago, on a scale that is undocumented in the modern ocean. Mats of the diatom Thalassiothrix were rapidly deposited as successive laminations at rates exceeding 10 cm per thousand years; mat deposits can be correlated for distances of more than 2,000 km. It is surprising that the laminations were preserved at all: conventional models suggest that bioturbation caused by the benthic sediment community will disrupt such laminations unless there is insufficient oxygen in the water to support the biological activity. In this case, however, the strength of the mats and the scale of their deposition may have overwhelmed the benthos, so that the laminations were preserved by physical means. These remarkable deposits provide a unique window into the Neogene tropical ocean-climate system, and should enable quantification of ancient deep-sea fluxes and the study of short-term (sub-Milankovitch) variability in the ocean.
C1 TEXAS A&M UNIV SYST,DEPT OCEANOG,COLL STN,TX 77843.
   TEXAS A&M UNIV SYST,OCEAN DRILLING PROGRAM,COLL STN,TX 77843.
C3 Texas A&M University System; Texas A&M University College Station; Texas A&M University System; Texas A&M University College Station
RP KEMP, AES (corresponding author), UNIV SOUTHAMPTON,DEPT OCEANOG,SOUTHAMPTON SO9 5NH,HANTS,ENGLAND.
NR 32
TC 106
Z9 118
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 141
EP 144
DI 10.1038/362141a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800054
DA 2026-03-10
ER

PT J
AU LARONNE, JB
   REID, I
AF LARONNE, JB
   REID, I
TI VERY HIGH-RATES OF BEDLOAD SEDIMENT TRANSPORT BY EPHEMERAL DESERT RIVERS
SO NATURE
LA English
DT Article
ID gravel-bed streams; suspended sediment; size distribution; dynamics; floods
AB GEOMORPHOLOGISTS have thought for some time that rates of sediment transfer might differ markedly in ephemeral and perennial rivers, and have used this idea to explain both the changing character of sedimentary successions and the morphology of rivers in sub-humid or semi-arid areas that have experienced significant shifts in climate during the Quaternary period1-5. But until now there has been a lack of suitable field data to confirm this suggestion, mainly because floods in arid zones are infrequent and unpredictable. Here we present bedload sediment transport data for an ephemeral river in Israel, which show it to be, on average, as much as 400 times more efficient at transporting coarse material than its perennial counterparts in humid zones. This suggests that existing predictive sediment transport equations24, developed and calibrated exclusively with data obtained in perennial rivers, are inadequate for application to rivers in arid environments. It also suggests that areas that are at risk of shifting from sub-humid to semi-arid conditions as a result of prospective global changes in climate may suffer severe sedimentation problems.
C1 LOUGHBOROUGH UNIV TECHNOL,DEPT GEOG,LOUGHBOROUGH LE11 3TU,LEICS,ENGLAND.
C3 Loughborough University
RP LARONNE, JB (corresponding author), BEN GURION UNIV NEGEV,DEPT GEOG & ENVIRONM DEV,IL-84105 BEER SHEVA,ISRAEL.
NR 24
TC 178
Z9 198
U1 1
U2 56
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 148
EP 150
DI 10.1038/366148a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600054
DA 2026-03-10
ER

PT J
AU MARTENSON, C
   STONE, K
   REEDY, M
   SHEETZ, M
AF MARTENSON, C
   STONE, K
   REEDY, M
   SHEETZ, M
TI FAST AXONAL-TRANSPORT IS REQUIRED FOR GROWTH CONE ADVANCE
SO NATURE
LA English
DT Article
ID nerve-cells; cytoskeleton; dynamics; membrane; tubulin; tension
AB GROWTH cones are capable of advancing despite linkage to a stationary axonal cytoskeleton in chick and murine dorsal root ganglion neurites1,2. Several lines of evidence point to the growth cone as the site of cytoskeletal elongation3,4. Fast axonal transport is probably the means by which cytoskeletal elements5 or cofactors are rapidly moved through the axon. We report that direct, but reversible, inhibition of fast axonal transport with laser optical tweezers inhibits growth cone motility if cytoskeletal attachment to the cell body is maintained. Advancement ceases after a distance-dependent lag period which correlates with the rate of fast axonal transport. But severing the axonal cytoskeleton with the laser tweezers allows growth cones to advance considerably further. We suggest that axon elongation requires fast axonal transport but growth cone motility does not.
C1 DUKE UNIV,MED CTR,DEPT PATHOL,DURHAM,NC 27710.
   DUKE UNIV,MED CTR,DEPT CELL BIOL,DURHAM,NC 27710.
C3 Duke University; Duke University
NR 14
TC 46
Z9 52
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 66
EP 69
DI 10.1038/366066a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700055
PM 7694151
DA 2026-03-10
ER

PT J
AU CALDEIRA, K
   KASTING, JF
AF CALDEIRA, K
   KASTING, JF
TI INSENSITIVITY OF GLOBAL WARMING POTENTIALS TO CARBON-DIOXIDE EMISSION SCENARIOS
SO NATURE
LA English
DT Article
ID model; ocean; co2
AB GLOBAL warming potentials for radiatively active trace gases (such as methane and chlorofluorocarbons) have generally been expressed1,2 relative to the time-integrated climate forcing per unit emission of carbon dioxide. Previous attempts to estimate the integrated climate forcing per unit CO2 emitted have focused on perturbations to steady-state conditions in carbon-cycle models. But for non-steady-state conditions, the integrated climate forcing from a CO2 perturbation depends both on the initial conditions and on future atmospheric CO2 concentrations. As atmospheric CO2 concentrations increase, the radiative forcing per unit CO2 emitted will become smaller because the strongest absorption bands will already be saturated. At the same time, higher concentrations of dissolved carbon in the surface ocean will reduce the ocean's ability to absorb excess CO2 from the atmosphere. Each of these effects taken alone would affect the climate forcing from a pulse of emitted CO2 by a factor of three or more; but here we show that, taken together, they compensate for each other. The net result is that the global warming potential of CO2 relative to other radiatively active trace gases is nearly independent of the CO2 emission scenario. Thus, the concept of the global warming potential remains useful, despite the nonlinearities in the climate system and uncertainties in future emissions.
C1 PENN STATE UNIV,CTR EARTH SYST SCI,UNIV PK,PA 16802.
C3 Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park
NR 9
TC 88
Z9 93
U1 0
U2 27
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 251
EP 253
DI 10.1038/366251a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500058
DA 2026-03-10
ER

PT J
AU SCHRODER, RR
   MANSTEIN, DJ
   JAHN, W
   HOLDEN, H
   RAYMENT, I
   HOLMES, KC
   SPUDICH, JA
AF SCHRODER, RR
   MANSTEIN, DJ
   JAHN, W
   HOLDEN, H
   RAYMENT, I
   HOLMES, KC
   SPUDICH, JA
TI 3-DIMENSIONAL ATOMIC MODEL OF F-ACTIN DECORATED WITH DICTYOSTELIUM MYOSIN-S1
SO NATURE
LA English
DT Article
ID heavy-chain; muscle; filaments
AB ELUCIDATION of the molecular contacts between actin and myosin is central to understanding the force-generating process in muscle and other cells. Actin, a highly conserved globular protein found in all eukaryotes, polymerizes into filaments (F-actin) for most of its biological functions. Myosins, which are more diverse in sequence, share a conserved globular head of about 900 amino acids in length (subfragment-1 or S1) at the N-terminal end of the molecule. S1 contains all the elements necessary for mechanochemical force transduction in vitro1,2. Here we report an atomic model for the actomyosin complex produced by combining the atomic X-ray structure of F-actin3,4 and chicken myosin S1(5) with a three-dimensional reconstruction from electron micrographs of frozen-hydrated F-actin decorated with recombinant Dictyostelium myosin S1. The accuracy of the reconstruction shows the position of actin and myosin molecules unambiguously.
C1 NATL INST MED RES,LONDON NW7 1AA,ENGLAND.
   UNIV WISCONSIN,INST ENZYME RES,MADISON,WI 53705.
   UNIV WISCONSIN,DEPT BIOCHEM,MADISON,WI 53705.
   STANFORD UNIV,MED CTR,SCH MED,BECKMAN CTR,DEPT BIOCHEM,STANFORD,CA 94305.
C3 MRC National Institute for Medical Research; University of Wisconsin System; University of Wisconsin Madison; University of Wisconsin System; University of Wisconsin Madison; Stanford University
RP SCHRODER, RR (corresponding author), MAX PLANCK INST MED RES,DEPT BIOPHYS,JAHNSTR 29,W-6900 HEIDELBERG,GERMANY.
NR 22
TC 293
Z9 311
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 171
EP 174
DI 10.1038/364171a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700057
PM 8321290
DA 2026-03-10
ER

PT J
AU TAYLOR, KC
   LAMOREY, GW
   DOYLE, GA
   ALLEY, RB
   GROOTES, PM
   MAYEWSKI, PA
   WHITE, JWC
   BARLOW, LK
AF TAYLOR, KC
   LAMOREY, GW
   DOYLE, GA
   ALLEY, RB
   GROOTES, PM
   MAYEWSKI, PA
   WHITE, JWC
   BARLOW, LK
TI THE FLICKERING SWITCH OF LATE PLEISTOCENE CLIMATE CHANGE
SO NATURE
LA English
DT Article
ID ice
AB POLAR ice contains a unique record of past climate variations; previous Greenland ice cores have documented relatively warm 'interstadial' periods during the last glaciation and short (century-scale) returns to colder conditions during the glacial to interglacial warming (see, for example, ref. 1). These climate features have also been observed to varying degrees in ocean sediment cores2-4 and terrestrial pollen and insect records5-7. Here we report electrical conductivity measurements from a new Greenland ice core, which confirm these previous observations, and also reveal a hitherto unrecognized mode of rapid climate variation. Fluctuations in ice conductivity on the scales of <5-20 years reflect rapid oscillations in the dust content of the atmosphere. This 'flickering' between two preferred states would seem to require extremely rapid reorganizations in atmospheric circulation.
C1 UNIV NEVADA,HYDROL HYDROGEOL SCI PROGRAM,RENO,NV 89557.
   PENN STATE UNIV,CTR EARTH SYST SCI,UNIV PK,PA 16802.
   PENN STATE UNIV,DEPT GEOSCI,UNIV PK,PA 16802.
   UNIV WASHINGTON,DEPT GEOL SCI,SEATTLE,WA 98195.
   UNIV WASHINGTON,QUATERNARY RES CTR,SEATTLE,WA 98195.
   UNIV NEW HAMPSHIRE,INST STUDY EARTH OCEANS & SPACE,GLACIER RES GRP,DURHAM,NH 03824.
   UNIV COLORADO,INST ARCTIC & ALPINE RES,BOULDER,CO 80309.
   UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309.
C3 Nevada System of Higher Education (NSHE); University of Nevada Reno; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; University of Washington; University of Washington Seattle; University of Washington; University of Washington Seattle; University System Of New Hampshire; University of New Hampshire; University of Colorado System; University of Colorado Boulder; University of Colorado System; University of Colorado Boulder
RP TAYLOR, KC (corresponding author), UNIV NEVADA SYST,DESERT RES INST,RENO,NV 89506, USA.
NR 27
TC 436
Z9 485
U1 0
U2 79
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 432
EP 436
DI 10.1038/361432a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300054
DA 2026-03-10
ER

PT J
AU XIONG, Y
   HANNON, GJ
   ZHANG, H
   CASSO, D
   KOBAYASHI, R
   BEACH, D
AF XIONG, Y
   HANNON, GJ
   ZHANG, H
   CASSO, D
   KOBAYASHI, R
   BEACH, D
TI P21 IS A UNIVERSAL INHIBITOR OF CYCLIN KINASES
SO NATURE
LA English
DT Article
ID activation
AB DEREGULATION of cell proliferation is a hallmark of neoplastic. transformation. Alteration in growth control pathways must translate into changes in the cell-cycle regulatory machinery, but the mechanism by which this occurs is largely unknown. Compared with normal human fibroblasts, cells transformed with a variety of viral oncoproteins show striking changes in the subunit composition of the cyclin-dependent kinases (CDKs)1. In normal cells, CDKs exist predominantly in multiple quaternary complexes, each containing a CDK, cyclin, proliferating cell nuclear antigen and the p21 protein. However, in many transformed cells, proliferating cell nuclear antigen and p21 are lost from these multiprotein enzymes. Here we have investigated the significance of this phenomenon by molecular cloning of p21 and in vitro reconstitution of the quaternary cell-cycle kinase complexes. We find that p21 inhibits the activity of each member of the cyclin/CDK family. Furthermore, overexpression of p21 inhibits the proliferation of mammalian cells. Our results indicate that p21 may be a universal inhibitor of cyclin kinases.
C1 COLD SPRING HARBOR LAB, HOWARD HUGHES MED INST, 1 BUNGTOWN RD, COLD SPRING HARBOR, NY 11724 USA.
C3 Cold Spring Harbor Laboratory; Howard Hughes Medical Institute
NR 13
TC 3364
Z9 3698
U1 3
U2 139
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 701
EP 704
DI 10.1038/366701a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500074
PM 8259214
DA 2026-03-10
ER

PT J
AU HAIN, R
   REIF, HJ
   KRAUSE, E
   LANGEBARTELS, R
   KINDL, H
   VORNAM, B
   WIESE, W
   SCHMELZER, E
   SCHREIER, PH
   STOCKER, RH
   STENZEL, K
AF HAIN, R
   REIF, HJ
   KRAUSE, E
   LANGEBARTELS, R
   KINDL, H
   VORNAM, B
   WIESE, W
   SCHMELZER, E
   SCHREIER, PH
   STOCKER, RH
   STENZEL, K
TI DISEASE RESISTANCE RESULTS FROM FOREIGN PHYTOALEXIN EXPRESSION IN A NOVEL PLANT
SO NATURE
LA English
DT Article
ID stilbene synthase; resveratrol; gene; grapevines; botrytis; vitis
AB ALTHOUGH phytoalexins1,2 have long been inferred to be important in the defence of plants against fungal infection1,2, there are few reports showing that they provide resistance to infection. Several plants, including grapevine, synthesize the stilbene-type phytoalexin resveratrol3-7 when attacked by pathogens. Stilbenes with fungicidal potential are formed in several unrelated plant species, such as peanut (Arachis hypogaea), grapevine (Vitis vinifera) and pine (Pinus sylvestris)3,5,11-15. Stilbene biosynthesis only specifically requires the presence of stilbene synthase 6,9. Furthermore, the precursor molecules for the formation of hydroxystilbenes are malonyl-CoA and p-coumaroyl-CoA, both present in plants9. To investigate the potential of stilbene biosynthetic genes in a strategy of engineering pathogen resistance, we isolated stilbene synthase genes from grapevine, where they are expressed at a high level, and transferred them into tobacco10. We report here that regenerated tobacco plants containing these genes are more resistant to infection by Botrytis cinerea. This is, to our knowledge, the first report of increased disease resistance in transgenic plants based on an additional foreign phytoalexin.
C1 UNIV MARBURG,FACHBEREICH CHEM,W-3550 MARBURG,GERMANY.
   MAX PLANCK INST ZUCHTUNGSFORSCH,W-5000 COLOGNE 30,GERMANY.
C3 Philipps University Marburg; Max Planck Society
RP HAIN, R (corresponding author), BAYER AG,PF-E-FU,INST BIOTECHNOL,W-5090 LEVERKUSEN 1,GERMANY.
NR 22
TC 492
Z9 614
U1 1
U2 86
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 153
EP 156
DI 10.1038/361153a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600059
PM 8421520
DA 2026-03-10
ER

PT J
AU HIRST, SJ
   HAYES, NA
   BURRIDGE, J
   PEARCE, FL
   FOREMAN, JC
AF HIRST, SJ
   HAYES, NA
   BURRIDGE, J
   PEARCE, FL
   FOREMAN, JC
TI HUMAN BASOPHIL DEGRANULATION IS NOT TRIGGERED BY VERY DILUTE ANTISERUM AGAINST HUMAN IGE
SO NATURE
LA English
DT Article
AB We have attempted to reproduce the findings of Benveniste and co-workers, who reported in 1988 that degranulation of human basophil leukocytes is triggered by very dilute (10(2)-10(120)) antiserum against IgE. The results were contrary to conventional scientific theory and were not satisfactorily explained. Following as closely as possible the methods of the original study, we can find no evidence for any periodic or polynomial change of degranulation as a function of anti-IgE dilution. Our results contain a source of variation for which we cannot account, but no aspect of the data is consistent with the previously published claims.
C1 UNIV LONDON UNIV COLL,DEPT PHARMACOL,GOWER ST,LONDON WC1E 6BT,ENGLAND.
   UNIV LONDON UNIV COLL,DEPT CHEM,LONDON WC1E 6BT,ENGLAND.
   UNIV LONDON UNIV COLL,DEPT STAT SCI,LONDON WC1E 6BT,ENGLAND.
C3 University of London; University College London; University of London; University College London; University of London; University College London
NR 1
TC 73
Z9 80
U1 2
U2 41
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 525
EP 527
DI 10.1038/366525a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800058
PM 8255290
DA 2026-03-10
ER

PT J
AU JAKOBOVITS, A
   MOORE, AL
   GREEN, LL
   VERGARA, GJ
   MAYNARDCURRIE, CE
   AUSTIN, HA
   KLAPHOLZ, S
AF JAKOBOVITS, A
   MOORE, AL
   GREEN, LL
   VERGARA, GJ
   MAYNARDCURRIE, CE
   AUSTIN, HA
   KLAPHOLZ, S
TI GERM-LINE TRANSMISSION AND EXPRESSION OF A HUMAN-DERIVED YEAST ARTIFICIAL CHROMOSOME
SO NATURE
LA English
DT Article
ID cells; recombination; library; sequences; cloning; gene; cdna; dna
AB INTRODUCTION of DNA fragments, hundreds of kilobases in size, into mouse embryonic stem (ES) cells would greatly advance the ability to manipulate the mouse genome. Mice generated from such modified cells would permit investigation of the function and expression of very large or crudely mapped genes. Large DNA molecules cloned into yeast artificial chromosomes (YACs) are stable and genetically manipulable within yeast1, suggesting yeast-cell fusion as an ideal method for transferring large DNA segments into mammalian cells. Introduction of YACs into different cell types by this technique has been reported2-8; however, the incorporation of yeast DNA along with the YAC has raised doubts as to whether ES cells, modified in this way. would be able to recolonize the mouse germ line5. Here we provide, to our knowledge, the first demonstration of germ-line transmission and expression of a large human DNA fragment, introduced into ES cells by fusion with yeast spheroplasts. Proper development was not impaired by the cointegration of a large portion of the yeast genome with the YAC.
RP JAKOBOVITS, A (corresponding author), CELL GENESYS INC, 322 LAKESIDE DR, FOSTER CITY, CA 94404 USA.
NR 22
TC 117
Z9 1377
U1 0
U2 15
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 255
EP 258
DI 10.1038/362255a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600059
PM 8459850
DA 2026-03-10
ER

PT J
AU BECKER, W
   TRUMPER, J
AF BECKER, W
   TRUMPER, J
TI DETECTION OF PULSED X-RAYS FROM THE BINARY MILLISECOND PULSAR J0437-4715
SO NATURE
LA English
DT Article
ID neutron stars; radiation; evolution; gaps
AB THE X-ray properties of pulsars (highly magnetized rotating neutron stars) depend mainly on the age of the star1. For young (less-than-or-equal-to 10(4) yr) pulsars, virtually all of the X-ray emission is pulsed, appearing as sharp bursts with a power-law spectrum; these emissions are thought to arise from the acceleration of electrons and positrons in the pulsar's magnetosphere2-5.  Older pulsars, on the other hand, exhibit broad X-ray pulses, a lower pulsed fraction and black-body spectra; this is ascribed to thermal emission from the surface of the cooling neutron star, the modulation of the X-rays reflecting temperature inhomogeneities induced by the strong magnetic fields6,7.  No thermal emission is expected for neutron stars older than approximately 10(6) yr (refs 8-10) in the absence of surface heating processes11-15. Here we report the discovery of pulsed X-ray emission from a approximately 2 x 10(9)-yr-old neutron star: the binary millisecond pulsar J0437 - 4715. The spectral properties of the pulsed emission suggest a thermal origin, requiring substantial heating of the neutron-star surface either by internal friction11-13 or by energetic particles streaming onto the polar cap from the pulsar's magnetosphere14,15.
RP BECKER, W (corresponding author), MAX PLANCK INST EXTRATERR PHYS,D-85740 GARCHING,GERMANY.
NR 33
TC 100
Z9 106
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 528
EP 530
DI 10.1038/365528a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100046
DA 2026-03-10
ER

PT J
AU CYR, H
   PACE, ML
AF CYR, H
   PACE, ML
TI MAGNITUDE AND PATTERNS OF HERBIVORY IN AQUATIC AND TERRESTRIAL ECOSYSTEMS
SO NATURE
LA English
DT Article
ID food-web manipulation; zooplankton community; south-africa; snow geese; lake; phytoplankton; marsh; macrophytes; productivity; populations
AB HERBIVORES can consume a sufficiently large proportion of primary production to regulate plant biomass in some environments1-3. Little is known, however, about how rates of herbivory vary among ecosystems and how herbivores influence the global distribution of vegetation. Patterns of herbivory in terrestrial ecosystems have been summarized recently4,5, but comparisons with aquatic systems are uncertain because past generalizations about herbivory in aquatic systems are based on surprisingly few data6-8. Herbivory is thought to be higher in aquatic than in terrestrial ecosystems9-11 and the impact of herbivores in aquatic systems is believed to decrease with increasing primary productivity12-15, a pattern opposite to that in terrestrial systems4,5. Here we examine these hypotheses using data from 44 aquatic sites. Herbivore biomass and herbivory rates increase at similar rates with increasing primary productivity in aquatic and in terrestrial systems. For a given level of primary productivity, aquatic and terrestrial herbivores reach similar biomass, but aquatic herbivores remove on average 51% of annual primary production, three times more than terrestrial herbivores. Mass-specific rates of herbivory are greater in aquatic than in terrestrial systems.
C1 INST ECOSYST STUDIES, MILLBROOK, NY 12545 USA.
   RUTGERS STATE UNIV, ECOL PROGRAM, PISCATAWAY, NJ 08855 USA.
C3 Cary Institute of Ecosystem Studies; Rutgers University System; Rutgers University New Brunswick
NR 48
TC 391
Z9 475
U1 1
U2 191
PU NATURE RESEARCH
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 148
EP 150
DI 10.1038/361148a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600057
DA 2026-03-10
ER

PT J
AU FAIRALL, L
   SCHWABE, JWR
   CHAPMAN, L
   FINCH, JT
   RHODES, D
AF FAIRALL, L
   SCHWABE, JWR
   CHAPMAN, L
   FINCH, JT
   RHODES, D
TI THE CRYSTAL-STRUCTURE OF A 2 ZINC-FINGER PEPTIDE REVEALS AN EXTENSION TO THE RULES FOR ZINC-FINGER DNA RECOGNITION
SO NATURE
LA English
DT Article
ID protein; binding; gene; specificity; domains; program
AB THE Cys2-His2 zinc-finger is the most widely occurring DNA-binding motif1-3. The first structure of a zinc-finger/DNA complex revealed a fairly simple mechanism for DNA recognition4 suggesting that the zinc-finger might represent a candidate template for designing proteins to recognize DNA-5. Residues at three key positions in an alpha-helical 'reading head' play a dominant role in base-recognition and have been targets for mutagenesis experiments aimed at deriving a recognition code6-8. Here we report the structure of a two zinc-finger DNA-binding domain from the protein Tramtrack complexed with DNA. The amino-terminal zinc-finger and its interaction with DNA illustrate several novel features. These include the use of a serine residue, which is semi-conserved and located outside the three key positions, to make a base contact. Its role in base-recognition correlates with a large, local, protein-induced deformation of the DNA helix at a flexible A-T-A sequence and may give insight into previous mutagenesis experiments9,10. It is apparent from this structure that zinc-finger/DNA recognition is more complex than was originally perceived.
RP FAIRALL, L (corresponding author), MRC,MOLEC BIOL LAB,HILLS RD,CAMBRIDGE CB2 2QH,ENGLAND.
NR 30
TC 323
Z9 399
U1 2
U2 27
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 483
EP 487
DI 10.1038/366483a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800070
PM 8247159
DA 2026-03-10
ER

PT J
AU SCHNUCHEL, A
   WILTSCHECK, R
   CZISCH, M
   HERRLER, M
   WILLIMSKY, G
   GRAUMANN, P
   MARAHIEL, MA
   HOLAK, TA
AF SCHNUCHEL, A
   WILTSCHECK, R
   CZISCH, M
   HERRLER, M
   WILLIMSKY, G
   GRAUMANN, P
   MARAHIEL, MA
   HOLAK, TA
TI STRUCTURE IN SOLUTION OF THE MAJOR COLD-SHOCK PROTEIN FROM BACILLUS-SUBTILIS
SO NATURE
LA English
DT Article
ID nuclear magnetic-resonance; spin coupling-constants; rna-binding domain; distance geometry; trypsin-inhibitor; escherichia-coli; identification; conformations; spectroscopy; cosy
AB THE cold-shock domain (CSD) is found in many eukaryotic transcriptional factors and is responsible for the specific binding to DNA of a cis-element called the Y-box1-3. The same domain exists in the sequence of the Xenopus RNA-binding proteins FRG Y1 and FRG Y2 (refs 1, 3). The major cold-shock proteins of Escherichia coli (CS7.4)4-7 and B. subtilis (CspB)8 have sequences that are more than 40 per cent identical to the cold-shock domain. We present here the three-dimensional structure of CspB determined by nuclear magnetic resonance spectroscopy. The 67-residue protein consists of an antiparallel five-stranded beta-barrel with strands connected by turns and loops. The structure resembles that of staphylococcal nuclease and the gene-5 single-stranded-DNA-binding protein9-11. A three-stranded beta-sheet, which contains the conserved RNA-binding motif RNP1 as well as a motif similar to RNP2 in two neighbouring antiparallel beta-strands12-14, has basic and aromatic residues at its surface which could serve as a binding site for single-stranded DNA. CspB binds to single-stranded DNA in gel retardation experiments.
C1 UNIV MARBURG,DEPT BIOCHEM,W-3550 MARBURG,GERMANY.
C3 Philipps University Marburg
RP SCHNUCHEL, A (corresponding author), MAX PLANCK INST BIOCHEM,W-8033 MARTINSRIED,GERMANY.
NR 28
TC 203
Z9 217
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 169
EP 171
DI 10.1038/364169a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700056
PM 8321289
DA 2026-03-10
ER

PT J
AU RYMER, H
   MURRAY, JB
   BROWN, GC
   FERRUCCI, F
   MCGUIRE, WJ
AF RYMER, H
   MURRAY, JB
   BROWN, GC
   FERRUCCI, F
   MCGUIRE, WJ
TI MECHANISMS OF MAGMA ERUPTION AND EMPLACEMENT AT MT ETNA BETWEEN 1989 AND 1992
SO NATURE
LA English
DT Article
ID kilauea volcano; mount etna; gravity; stress; hawaii
AB THE present eruption sequence of Mt Etna began during September 1989 with extensive fracturing, and culminated in 1991-93 with the largest lava eruption this century1. Here we present measurements of gravity and ground deformation which, in conjunction with seismic data, provide a detailed record of the processes occurring before and during eruption. These reflect a complex interplay between magma injection into the paths of lowest compressive stress through the volcano flanks, forcing elastic deformation, and fracture growth in response to gravitational stresses. We find that after the end of the eruptive activity in 1989, fractures in the south-southeast flank of the volcano remained unfilled until some months before the 1991-93 eruption. These results indicate the utility of microgravity monitoring, as the precursory processes that we identify were largely undetected by seismic and ground deformation monitoring.
C1 CTR OPERAT CATANIA,NAZL VULCANOL GRP,I-95123 CATANIA,ITALY.
   CHELTENHAM & GLOUCESTER COLL HIGHER EDUC,CHELTENHAM GL50 3PP,ENGLAND.
C3 University of Gloucestershire
RP RYMER, H (corresponding author), OPEN UNIV,DEPT EARTH SCI,WALTON HALL,MILTON KEYNES MK7 6AA,BUCKS,ENGLAND.
NR 19
TC 66
Z9 66
U1 0
U2 13
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 439
EP 441
DI 10.1038/361439a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300056
DA 2026-03-10
ER

PT J
AU KUPERMAN, A
   NADIMI, S
   OLIVER, S
   OZIN, GA
   GARCES, JM
   OLKEN, MM
AF KUPERMAN, A
   NADIMI, S
   OLIVER, S
   OZIN, GA
   GARCES, JM
   OLKEN, MM
TI NONAQUEOUS SYNTHESIS OF GIANT CRYSTALS OF ZEOLITES AND MOLECULAR-SIEVES
SO NATURE
LA English
DT Article
ID crystallization
AB IN the rapidly developing area of advanced zeolite materials science, the development of novel optical, electronic and magnetic materials1-5 requires the synthesis of large single crystals of a well defined habit. Crystals of a specified size and shape are needed to fabricate membranes and sensor devices6,7. Large crystals of zeolites and molecular sieves are essential for refining structures and elucidating the intrinsic absorption and diffusion properties of these materials8,9. Here we present a method for growing uniformly large and morphologically well defined single crystals of all-silica, aluminosilicate and aluminophosphate molecular sieves with dimensions in the size range 0.4-5.0 mm. Our synthetic method relies on the use of a non-aqueous solvent, a mineralizer, an optional organic templating species and reagent amounts of water. We have prepared both large-pore and small-pore materials of various framework composition and structure type.
C1 DOW CHEM CO USA, MIDLAND, MI 48674 USA.
C3 Dow Chemical Company
RP KUPERMAN, A (corresponding author), UNIV TORONTO, LASH MILLER CHEM LABS, 80 ST GEORGE ST, TORONTO M5S 1A1, ONTARIO, CANADA.
NR 25
TC 280
Z9 297
U1 2
U2 92
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 239
EP 242
DI 10.1038/365239a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100049
DA 2026-03-10
ER

PT J
AU MARCHETTI, K
AF MARCHETTI, K
TI DARK HABITATS AND BRIGHT BIRDS ILLUSTRATE THE ROLE OF THE ENVIRONMENT IN SPECIES DIVERGENCE
SO NATURE
LA English
DT Article
ID sexual selection; physalaemus-pustulosus; sensory exploitation; color patterns; evolution; frog; speciation; warblers; song
AB ANIMALS exhibit a diversity of colour patterns that are commonly used in interspecific and intraspecific communication1-3. Factors influencing the evolution of signals used in communication include the properties of the physical environment in which the signal is generated2-10, the perceptual systems of individuals (such as potential mates or predators) receiving the signal2,3,11-16, and the nature of the information signalled. In warblers of the genus Phylloscopus, species differences in colour patterns are correlated with light intensity of the habitat: brighter species live in darker habitats. I report here two observations that colour patterns function to increase conspicuousness, and are used in intraspecific communication. First, individuals make themselves temporarily more conspicuous by flashing the bright colour patterns in display, and are less conspicuous when not displaying. Second, experimentally increasing conspicuousness of males within a given habitat increases territory size, whereas experimentally reducing conspicuousness results in either a smaller territory or its total loss. Traits used in intraspecific communication are often thought to diverge as a result of variation in perceptual systems2,3,13,15-17. This study shows that variation in the physical environment can cause species divergence, and this will occur whether perceptual systems are variable or relatively constant.
C1 UNIV CALIF DAVIS,CTR POPULAT BIOL,DAVIS,CA 95616.
C3 University of California System; University of California Davis
RP MARCHETTI, K (corresponding author), UNIV CALIF DAVIS,ZOOL SECT,DAVIS,CA 95616, USA.
NR 28
TC 268
Z9 299
U1 0
U2 79
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 149
EP 152
DI 10.1038/362149a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800057
DA 2026-03-10
ER

PT J
AU MOORE, MJ
   SHARP, PA
AF MOORE, MJ
   SHARP, PA
TI EVIDENCE FOR 2 ACTIVE-SITES IN THE SPLICEOSOME PROVIDED BY STEREOCHEMISTRY OF PREMESSENGER RNA SPLICING
SO NATURE
LA English
DT Article
ID small nuclear-rna; tetrahymena ribozyme; mutational analysis; binding-site; yeast; step; substitution; polymerase; adenosine; cleavage
AB EXCISION of introns from nuclear precursors to messenger RNAs (pre-mRNAs) by the spliceosome requires two distinct phosphodiester transfer (transesterification) reactions: exchange of a 3'-5' for a 2'-5' bond in the first step (lariat formation) and exchange of one 3'-5' phosphodiester for another in the second step (exon ligation)1-3. We report here determination of the stereochemical course of each step using splicing substrates that contained a chiral phosphorothioate. This has provided strong evidence that both steps occur as single 'in-line' SN2 nucleophilic displacement reactions, analogous to the mechanism of group I self-splicing introns4,5. Additionally, because both steps are strongly inhibited by the R(P) phosphorothioate diastereomer, but not by S(P), the spliceosome probably shifts between two active sites in catalysis of the two steps. Chemical and stereochemical similarities suggest that the catalytic site for the second step of spliceosomal processing is related to that of group I self-splicing introns.
C1 MIT, DEPT BIOL, CAMBRIDGE, MA 02139 USA.
C3 Massachusetts Institute of Technology (MIT)
RP MOORE, MJ (corresponding author), MIT, CTR CANC RES, CAMBRIDGE, MA 02139 USA.
NR 36
TC 194
Z9 263
U1 0
U2 18
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 364
EP 368
DI 10.1038/365364a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600060
PM 8397340
DA 2026-03-10
ER

PT J
AU DEBONDT, HL
   ROSENBLATT, J
   JANCARIK, J
   JONES, HD
   MORGAN, DO
   KIM, SH
AF DEBONDT, HL
   ROSENBLATT, J
   JANCARIK, J
   JONES, HD
   MORGAN, DO
   KIM, SH
TI CRYSTAL-STRUCTURE OF CYCLIN-DEPENDENT KINASE-2
SO NATURE
LA English
DT Article
ID p34cdc2 protein-kinase; schizosaccharomyces-pombe; saccharomyces-cerevisiae; regulatory phosphorylation; catalytic subunit; molecular-cloning; sequence-analysis; mutant alleles; gene cdc28; identification
AB Cyclin-dependent kinase 2 (CDK2) is a member of a highly conserved family of protein kinases that regulate the eukaryotic cell cycle. The crystal structures of the human CDK2 apoenzyme and its Mg2+ ATP complex have been determined to 2.4angstrom resolution. The structure is bi-lobate, like that of the cyclic AMP-dependent protein kinase, but contains a unique helix-loop segment that interferes with ATP and protein substrate binding and probably plays a key part in the regulation of all cyclin-dependent kinases.
C1 UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA.
   LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA.
   UNIV CALIF SAN FRANCISCO, DEPT PHYSIOL, SAN FRANCISCO, CA 94143 USA.
C3 University of California System; University of California Berkeley; United States Department of Energy (DOE); Lawrence Berkeley National Laboratory; University of California System; University of California San Francisco
NR 50
TC 856
Z9 976
U1 2
U2 49
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 595
EP 602
DI 10.1038/363595a0
PG 8
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900045
PM 8510751
DA 2026-03-10
ER

PT J
AU IKEDA, T
   SASAKI, T
   ICHIMURA, K
AF IKEDA, T
   SASAKI, T
   ICHIMURA, K
TI PHOTOCHEMICAL SWITCHING OF POLARIZATION IN FERROELECTRIC LIQUID-CRYSTAL FILMS
SO NATURE
LA English
DT Article
ID isothermal phase-transition; laser-beam; displays
AB LIQUID crystals have been used extensively as active media in display devices such as full-colour television screens. These devices are generally based on changes in the arrangement of the liquid-crystal molecules induced by electric fields, which change their optical properties1. Ferroelectric liquid crystals2,3 exhibit spontaneous polarization and therefore show a faster response to changes in the applied field. Switching of this field causes a reversal in the direction of polarization2-5. Here we report polarization switching in ferroelectric liquid crystals driven by a photochemical process. The liquid-crystal films are doped with a photochromic compound which undergoes trans-cis isomerization on irradiation. Photoisomerization induces a change in the switching potential of the host liquid-crystal film, and thereby causes switching at the irradiated sites. The process is fast, stable, reversible and repeatable, and should be exploitable in device applications.
RP IKEDA, T (corresponding author), TOKYO INST TECHNOL,PRESTO,JRDC,RESOURCES UTILIZAT RES LAB,4259 NAGATSUTA,MIDORI KU,YOKOHAMA,KANAGAWA 227,JAPAN.
NR 16
TC 290
Z9 302
U1 1
U2 76
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 428
EP 430
DI 10.1038/361428a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300052
DA 2026-03-10
ER

PT J
AU KELLER, CK
   WOOD, BD
AF KELLER, CK
   WOOD, BD
TI POSSIBILITY OF CHEMICAL-WEATHERING BEFORE THE ADVENT OF VASCULAR LAND PLANTS
SO NATURE
LA English
DT Article
ID carbon-dioxide; unsaturated zone; isotopic composition; phanerozoic time; united-states; great plains; clayey till; atmosphere; co2; hydrogeochemistry
AB CHEMICAL weathering today is generally assumed to occur primarily in soils1,2. The rise of vascular plants during the Silurian and Devonian periods about 400 Myr ago brought about an increase in soil microbial activity and thus in soil CO2 generation, and it has therefore been widely believed that, as a result of these changes, soil CO2 replaced atmospheric CO2 as the primary agent of chemical weathering3-6. Here we show that the aerated region above the water table (the vadose zone) exerts a strong influence on the CO2 concentration to which runoff is exposed as it percolates beneath the soil, and we argue that this could have been the case before the Silurian. We present calculations which show that, for present-day atmospheric CO2 concentrations, a low level of microbial - respiration may be sufficient to support appreciable CO2 concentrations in the vadose zone because of the slow rate of CO2 loss to the surface. Despite the small amount of microbial respiration in pre-Silurian soilS, CO2 concentrations in subsoil vadose zones might therefore have been sufficient to account for the apparent constancy of chemical weathering since the mid-Proterozoic7, obviating the need to invoke high levels of atmospheric CO2 to explain the weathering record.
C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA.
C3 United States Department of Energy (DOE); Pacific Northwest National Laboratory
RP KELLER, CK (corresponding author), WASHINGTON STATE UNIV, DEPT GEOL, PULLMAN, WA 99164 USA.
NR 42
TC 54
Z9 59
U1 1
U2 13
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 223
EP 225
DI 10.1038/364223a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300052
DA 2026-03-10
ER

PT J
AU MOSKOPHIDIS, D
   LECHNER, F
   PIRCHER, H
   ZINKERNAGEL, RM
AF MOSKOPHIDIS, D
   LECHNER, F
   PIRCHER, H
   ZINKERNAGEL, RM
TI VIRUS PERSISTENCE IN ACUTELY INFECTED IMMUNOCOMPETENT MICE BY EXHAUSTION OF ANTIVIRAL CYTOTOXIC EFFECTOR T-CELLS
SO NATURE
LA English
DT Article
ID lymphocytic choriomeningitis virus; nervous-system disease; extrathymic tolerance; viral persistence; clonal anergy; selection; induction; mechanism; variants; suppression
AB VIRUSES that are non- or poorly cytopathic have developed various strategies to avoid elimination by the immune system and to persist in the host1-3. Acute infection of adult mice with the noncytopathic lymphocytic choriomeningitis virus (LCMV) normally induces a protective cytotoxic T-cell response that also causes immunopathology4-7. But some LCMV strains (such as DOCILE8 (LCMV-D) or Cl-13 Armstrong (Cl-13)) derived from virus carrier mice tend to persist after acute infection of adult mice without causing lethal immunopathological disease4,5. Tendency to persist correlates with tropism8,10, rapidity of virus spread8 and virus mutations11,12. We report here that these LCMV isolates may persist because they induce most of the specific antiviral CD8+ cytotoxic T cells so completely that they all disappear within a few days and therefore neither eliminate the virus nor cause lethal immunopathology. The results illustrate that partially and sequentially induced (protective) immunity or complete exhaustion of T-cell immunity (high zone tolerance) are quantitatively different points on the scale of immunity; some viruses exploit the latter possibility to persist in an immunocompetent host.
RP MOSKOPHIDIS, D (corresponding author), UNIV ZURICH, DEPT PATHOL, INST EXPTL IMMUNOL, STERNWARTSTR 2, CH-8091 ZURICH, SWITZERLAND.
NR 43
TC 1113
Z9 1278
U1 3
U2 42
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 758
EP 761
DI 10.1038/362758a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000059
PM 8469287
DA 2026-03-10
ER

PT J
AU MANDEL, LJ
   BACALLAO, R
   ZAMPIGHI, G
AF MANDEL, LJ
   BACALLAO, R
   ZAMPIGHI, G
TI UNCOUPLING OF THE MOLECULAR FENCE AND PARACELLULAR GATE FUNCTIONS IN EPITHELIAL TIGHT JUNCTIONS
SO NATURE
LA English
DT Article
ID mdck cells; polarity; permeability; resistance; membrane
AB DURING epithelial morphogenesis, the establishment of tight junctions precedes the development of both the asymmetry in protein and lipid composition between apical and basolateral cell surfaces (the 'fence' function) and the restriction in the transport of ions and nonelectrolytes through the extracellular clefts between cells (the 'gate' function)1,2. Molecular models that explain both functions envision strands of particles extending as rings in the cell's perimeter that interact with similar strands located at the apposing cell2-5. This model accounts for the 'fence' function, because the strands prevent diffusion of protein and lipids, and also for the 'gate' function, because the interaction between strands minimizes the width of the extracellular clefts, increasing transepithelial resistance to ions and decreasing non-electrolyte permeability. Here we describe the results of energy depletion, which for the first time separates both functions: it abolishes the gate function, as determined by the dramatic decrease in transepithelial resistance, but it leaves the fence function intact, as determined by the maintenance of lipid polarity.
C1 NORTHWESTERN UNIV,DEPT MOLEC CELLULAR & STRUCT BIOL,DIV NEPHROL & HYPERTENS,CHICAGO,IL 60611.
   UNIV CALIF LOS ANGELES,DEPT ANAT & CELL BIOL,LOS ANGELES,CA 90024.
C3 Northwestern University; University of California System; University of California Los Angeles
RP MANDEL, LJ (corresponding author), DUKE UNIV,MED CTR,DEPT CELL BIOL,DIV PHYSIOL,DURHAM,NC 27710, USA.
NR 23
TC 249
Z9 270
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 552
EP 555
DI 10.1038/361552a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400066
PM 8429911
DA 2026-03-10
ER

PT J
AU SZCZEPANSKI, J
   VALA, M
AF SZCZEPANSKI, J
   VALA, M
TI LABORATORY EVIDENCE FOR IONIZED POLYCYCLIC AROMATIC-HYDROCARBONS IN THE INTERSTELLAR-MEDIUM
SO NATURE
LA English
DT Article
ID spectra; dust
AB THE origin of the broad interstellar infrared emission bands (at 3.3, 6.2, 7.8, 8.6 and 11.3 mum) found in the vicinity of many galactic and extragalactic sources is still poorly understood. The original suggestion' that the bands are associated with aromatic species embedded in small carbon particles was later challenged by the proposal2 that they originate from vapour-phase, neutral polycyclic aromatic hydrocarbons (PAHs); Allamandola et al. independently argued3 that PAH cations are the source of the bands. This latter proposal has steadily gained acceptance, but the lack of experimentally determined emission spectra of PAH cations has made it difficult to test the idea. We have recently measured the visible and infrared spectra of the neutrals and cations of four PAHs-naphthalene4, anthracene5, pyrene6 and perylene7-dispersed in argon matrices at 12 K, to approximate the low-pressure, gas-phase conditions of the interstellar medium. Here we compare the infrared absorption from these four molecules (neutrals and cations), integrated over the spectral regions corresponding to the interstellar bands, with the astronomical observations. We rind that the interstellar bands cannot be explained solely on the basis of neutral PAH species, but that cations must be a significant, and in some cases dominant, component.
C1 UNIV FLORIDA,CTR CHEM PHYS,GAINESVILLE,FL 32611.
C3 State University System of Florida; University of Florida
RP SZCZEPANSKI, J (corresponding author), UNIV FLORIDA,DEPT CHEM,GAINESVILLE,FL 32611, USA.
NR 14
TC 132
Z9 136
U1 0
U2 18
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 699
EP 701
DI 10.1038/363699a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900048
DA 2026-03-10
ER

PT J
AU HES, R
   BARTHEL, PD
   FOSBURY, RAE
AF HES, R
   BARTHEL, PD
   FOSBURY, RAE
TI SUPPORT FOR A UNIFIED MODEL OF RADIO GALAXIES AND QUASARS FROM ISOTROPIC [O-II] EMISSION
SO NATURE
LA English
DT Article
ID sample
AB UNIFIED models1-3 of radio-loud quasars and powerful radio galaxies suggest that they are intrinsically similar objects observed from different angles. This can be tested by comparing the isotropically emitted radiation from the spatially extended nebulae surrounding the nuclei; the unified models predict that the intensities of these emissions should be comparable for the two classes of object. But when this prediction was examined4 for the [O III] 5,007-angstrom emission line, it was found that quasar [O III] luminosities significantly exceed those of otherwise similar radio galaxies. We have measured the spatially integrated [O II] 3,727-angstrom emission-line luminosities for a number of quasars and radio galaxies taken from the 3C catalogue. Supplementing our data with values from the literature, we find no systematic difference in the [O II] luminosities. We argue that this emission is indeed isotropic, and that our results are consistent with the unification hypothesis; the [O III] line, on the other hand, may still have a significant component from the nuclear region, and thus be subject to pronounced anisotropic obscuration.
C1 EUROPEAN SO OBSERV,SPACE TELESCOPE EUROPEAN COORDINATING FACIL,W-8046 GARCHING,GERMANY.
C3 European Southern Observatory
RP HES, R (corresponding author), KAPTEYN ASTRON INST,POB 800,9700 AV GRONINGEN,NETHERLANDS.
NR 27
TC 89
Z9 90
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 326
EP 328
DI 10.1038/362326a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600053
PM 29633997
DA 2026-03-10
ER

PT J
AU BUKRINSKY, MI
   HAGGERTY, S
   DEMPSEY, MP
   SHAROVA, N
   ADZHUBEI, A
   SPITZ, L
   LEWIS, P
   GOLDFARB, D
   EMERMAN, M
   STEVENSON, M
AF BUKRINSKY, MI
   HAGGERTY, S
   DEMPSEY, MP
   SHAROVA, N
   ADZHUBEI, A
   SPITZ, L
   LEWIS, P
   GOLDFARB, D
   EMERMAN, M
   STEVENSON, M
TI A NUCLEAR-LOCALIZATION SIGNAL WITHIN HIV-1 MATRIX PROTEIN THAT GOVERNS INFECTION OF NONDIVIDING CELLS
SO NATURE
LA English
DT Article
ID human-immunodeficiency-virus; immune-deficiency syndrome; retroviral dna; complex; gene; integration; monocytes; invitro; virions
AB PERMISSIVENESS of the host cell to productive infection by onco-retroviruses is cell-cycle dependent1, and nuclear localization of viral nucleoprotein preintegration complexes will occur only after cells have passed through mitosis2. In contrast, establishment of an integrated provirus after infection by the lentivirus HIV-1 is independent of host cell proliferation3-5. The ability of HIV-1 to replicate in non-dividing cells is partly accounted for by the karvophilic properties of the viral preintegration complex which, after virus infection, is actively transported to the host cell nucleus. Here we report that the gag matrix protein of HIV-1 contains a nuclear localization sequence which, when conjugated to a heterologous protein, directs its nuclear import. In addition, HIV-1 mutants containing amino-acid substitutions in this nuclear localization signal integrate and replicate within dividing but not growth-arrested cells, and thus display a phenotype more representative of an onco-retrovirus.
C1 UNIV NEBRASKA,MED CTR,DEPT PATHOL & MICROBIOL,OMAHA,NE 68198.
   IMPERIAL CANC RES FUND,BIOMOLEC MODELLING LAB,LONDON WC2A 3PX,ENGLAND.
   UNIV NEBRASKA,MED CTR,EPPLEY INST RES,OMAHA,NE 68198.
   UNIV ROCHESTER,DEPT BIOL,ROCHESTER,NY 14627.
   FRED HUTCHINSON CANC RES CTR,PROGRAM MOLEC MED,SEATTLE,WA 98104.
C3 University of Nebraska System; University of Nebraska Medical Center; Cancer Research UK; University of Nebraska System; University of Nebraska Medical Center; University of Rochester; Fred Hutchinson Cancer Center
FU NCRR NIH HHS [R01 RR011589] Funding Source: Medline; NIAID NIH HHS [R37 AI037475, R21 AI127091] Funding Source: Medline; NIMH NIH HHS [R01 MH093306, R01 MH064411] Funding Source: Medline
NR 27
TC 719
Z9 883
U1 1
U2 37
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 666
EP 669
DI 10.1038/365666a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600065
PM 8105392
DA 2026-03-10
ER

PT J
AU FORD, AM
   RIDGE, SA
   CABRERA, ME
   MAHMOUD, H
   STEEL, CM
   CHAN, LC
   GREAVES, M
AF FORD, AM
   RIDGE, SA
   CABRERA, ME
   MAHMOUD, H
   STEEL, CM
   CHAN, LC
   GREAVES, M
TI INUTERO REARRANGEMENTS IN THE TRITHORAX-RELATED ONCOGENE IN INFANT LEUKEMIAS
SO NATURE
LA English
DT Article
ID acute nonlymphocytic leukemia; acute lymphoblastic-leukemia; acute myeloid-leukemia; cell; twins; gene; translocations; abnormality; expression; children
AB THE majority (approximately 75%) of infant acute leukaemias have a reciprocal translocation between chromosome 11q23 and one of several partner chromosomes1. The gene at 11q23 (named MLL, ALL-1, HRX or HTRX-1; refs 2-6) has been cloned and shares homology with the Drosophila developmental gene trithorax3-5. Rearrangements of this gene (called HRX here) occur in introns and cluster in a region of approximately 10 kb; individual patients have different breakpoints3-10. Here we describe three pairs of infant twins with concordant leukaemia who each share unique (clonal) but non-constitutive HRX rearrangements in their leukaemic cells, providing evidence that the leukaemogenic event originates in utero and unequivocal support for the intra-placental 'metastasis' hypothesis for leukaemia concordance in twins11.
C1 UNIV CHILE, HAEMATOL SECT, SANTIAGO, CHILE.
   ST JUDE CHILDRENS RES HOSP, DEPT HEMATOL ONCOL, MEMPHIS, TN 38101 USA.
   UNIV TENNESSEE, MEMPHIS COLL MED, MEMPHIS, TN 38101 USA.
   WESTERN GEN HOSP, MRC, HUMAN GENET UNIT, EDINBURGH EH4 2XU, MIDLOTHIAN, SCOTLAND.
   UNIV HONG KONG, QUEEN MARY HOSP COMPOUND, DEPT PATHOL, HONG KONG, HONG KONG SAR.
C3 Universidad de Chile; St Jude Children's Research Hospital; University of Tennessee System; University of Tennessee Health Science Center; University of Edinburgh; University of Hong Kong
RP FORD, AM (corresponding author), INST CANC RES, CHESTER BEATTY LABS, CTR LEUKAEMIA RES FUND, 237 FULHAM RD, LONDON SW3 6JB, ENGLAND.
NR 36
TC 367
Z9 399
U1 0
U2 8
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 358
EP 360
DI 10.1038/363358a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700056
PM 8497319
DA 2026-03-10
ER

PT J
AU COOPER, HM
   HERBIN, M
   NEVO, E
AF COOPER, HM
   HERBIN, M
   NEVO, E
TI OCULAR REGRESSION CONCEALS ADAPTIVE PROGRESSION OF THE VISUAL-SYSTEM IN A BLIND SUBTERRANEAN MAMMAL
SO NATURE
LA English
DT Article
ID mole rat; retinal projections; spalax-ehrenbergi; albino-rat; nucleus; melatonin; vasopressin; pathway; hamster; brain
AB THE mole rat, Spalax ehrenberghi, is an extreme example of natural visual degeneration in mammals: visual pathways are regressed and incomplete1, and the absence of visual cortical potentials or an overt behavioural response to light have led to the conclusion that Spalax is completely blind2-4. But structural and molecular investigations of the atrophied, subcutaneous eye suggest a functional role for the retina in light perception5,6, and entrainment of circadian locomotor and thermoregulatory rhythms by ambient light demonstrates a capacity for photoperiodic detection2,7-9. We report here that severe regression of thalamic and tectal structures involved in form and motion perception is coupled to a selective hypertrophy of structures subserving photoperiodic functions. As an alternative to the prevalent view that ocular regression results from negative or nonselective evolutionary processes10-12, the differential reduction and expansion of visual structures in Spalax can be explained as an adaptive response to the underground environment.
C1 MUSEUM NATL HIST NAT, ANAT COMPAREE LAB, F-75005 PARIS, FRANCE.
   UNIV HAIFA, INST EVOLUT, HAIFA, ISRAEL.
C3 Museum National d'Histoire Naturelle (MNHN); University of Haifa
RP COOPER, HM (corresponding author), INSERM, U371, F-69500 BRON, FRANCE.
NR 34
TC 169
Z9 178
U1 0
U2 13
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 156
EP 159
DI 10.1038/361156a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600060
PM 7678449
DA 2026-03-10
ER

PT J
AU KEKULE, AS
   LAUER, U
   WEISS, L
   LUBER, B
   HOFSCHNEIDER, PH
AF KEKULE, AS
   LAUER, U
   WEISS, L
   LUBER, B
   HOFSCHNEIDER, PH
TI HEPATITIS-B VIRUS TRANSACTIVATOR HBX USES A TUMOR PROMOTER SIGNALING PATHWAY
SO NATURE
LA English
DT Article
ID protein-kinase-c; mammalian-cells; x-protein; potent inhibitor; gene; dna; expression; phosphatidylcholine; hepatocytes; activation
AB THE hepatitis B virus (HBV) transactivator protein HBx is enigmatic in that it stimulates a striking variety of promoters which do not share a common cis-regulatory element1-5. As it does not bind to DNA6,7, it has been speculated that HBx acts indirectly through cellular pathways4,6-8. Under certain conditions HBx can have an oncogenic potential, which may be relevant for HBV-associated liver carcinogenesis9-11, but until now the mechanism for transactivation and cell transformation by HBx was unclear. We report here that HBx uses a complex signal transduction pathway for transactivation. An increase in the endogenous protein kinase C (PKC) activator sn-1,2-diacylglycerol and the subsequent activation of PKC give rise to activation of the transcription factor AP-1 (Jun-Fos). As a result, HBx transactivates through binding sites for AP-1 and other PKC-dependent transcription factors (AP-2, NF-kappaB), thereby explaining the as-yet incomprehensible variety of HBx-inducible genes. As the PKC signal cascade also mediates cell transformation by tumour-promoting agents, the mechanism presented here might account for the oncogenic potential of HBx.
RP KEKULE, AS (corresponding author), MAX PLANCK INST BIOCHEM,KLOPFERSPITZ 18A,W-8033 MARTINSRIED,GERMANY.
NR 41
TC 359
Z9 384
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 742
EP 745
DI 10.1038/361742a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900062
PM 8441471
DA 2026-03-10
ER

PT J
AU HAMMER, F
   LEFEVRE, O
   ANGONIN, MC
AF HAMMER, F
   LEFEVRE, O
   ANGONIN, MC
TI A YOUNG SOURCE OF OPTICAL-EMISSION FROM DISTANT RADIO GALAXIES
SO NATURE
LA English
DT Article
ID high spatial-resolution; high-redshift; identifications
AB DISTANT radio galaxies provide valuable insights into the properties of the young Universe-they are the only known extended optical sources at high redshift and might represent an early stage in the formation and evolution of galaxies in general. This extended optical emission often has very complex morphologies, but the origin of the light is still unclear. Here we report spectroscopic observations for several distant radio galaxies (0.75 less-than-or-equal-to z less-than-or-equal-to 1.1) in which the rest-frame spectra exhibit featureless continua between 2,500 angstrom and 5,000 angstrom. We see no evidence for the break in the spectrum at 4,000 angstrom expected for an old stellar population1-3, and suggest that young stars or scattered emissions from the active nuclei are responsible for most of the observed light. In either case, this implies that the source of the optical emission is comparable in age to the associated radio source, namely 10(7) years or less.
C1 CANADA FRANCE HAWAII TELESCOPE CORP,KAMUELA,HI 96743.
C3 Canada France Hawaii Telescope
RP HAMMER, F (corresponding author), OBSERV PARIS,DEPT ASTROPHYS EXTRAGALACT & COSMOL,F-92195 MEUDON,FRANCE.
NR 20
TC 15
Z9 15
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 324
EP 326
DI 10.1038/362324a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600052
PM 29634006
DA 2026-03-10
ER

PT J
AU RANDRIAMAMPITA, C
   TSIEN, RY
AF RANDRIAMAMPITA, C
   TSIEN, RY
TI EMPTYING OF INTRACELLULAR CA2+ STORES RELEASES A NOVEL SMALL MESSENGER THAT STIMULATES CA2+ INFLUX
SO NATURE
LA English
DT Article
ID plasma-membrane; human-neutrophils; calcium channels; mast-cells; t-cells; ca-2+; permeability; entry; lymphocytes; fibroblasts
AB INTRACELLULAR Ca2+ signals that last more than a few minutes after the onset of stimulation depend critically on influx of extracellular Ca2+. Such Ca2+ influx can be triggered in many cell types by depletion of intracellular Ca2+ stores without detectable elevations of known messengers. The mechanism by which store depletion can control plasma membrane Ca2+ permeability remains controversial1-7. Here we present evidence for a novel soluble mediator. Calcium depletion of a lymphocyte cell line caused the messenger to be released from intracellular organelles into the cytoplasm and to a much lesser extent into the extracellular medium. The messenger caused Ca2+ influx when applied to macrophages, astrocytoma cells, and fibroblasts and was therefore named CIF (or Ca2+-influx factor). CIF appears to have hydroxyls (or hydroxyl and amino groups) on adjacent carbons, a phosphate, and a M(r) under 500.
C1 UNIV CALIF SAN DIEGO,DEPT PHARMACOL,LA JOLLA,CA 92093.
   ECOLE NORMALE SUPER,NEUROBIOL LAB,F-75231 PARIS 05,FRANCE.
   UNIV CALIF SAN DIEGO,HOWARD HUGHES MED INST,LA JOLLA,CA 92093.
C3 University of California System; University of California San Diego; Universite PSL; Ecole Normale Superieure (ENS); University of California System; University of California San Diego; Howard Hughes Medical Institute
NR 31
TC 864
Z9 920
U1 0
U2 13
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 809
EP 814
DI 10.1038/364809a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100058
PM 8355806
DA 2026-03-10
ER

PT J
AU BLUM, JD
   CHAMBERLAIN, CP
   HINGSTON, MP
   KOEBERL, C
   MARIN, LE
   SCHURAYTZ, BC
   SHARPTON, VL
AF BLUM, JD
   CHAMBERLAIN, CP
   HINGSTON, MP
   KOEBERL, C
   MARIN, LE
   SCHURAYTZ, BC
   SHARPTON, VL
TI ISOTOPIC COMPARISON OF K/T BOUNDARY IMPACT GLASS WITH MELT ROCK FROM THE CHICXULUB AND MANSON IMPACT STRUCTURES
SO NATURE
LA English
DT Article
ID cretaceous-tertiary boundary; target materials; tektites; age; haiti; constraints; crater; provenance
AB THE discussion of candidate source craters for the catastrophic impact that occurred at the boundary between the Cretaceous and Tertiary periods (K/T boundary) has recently centred on two buried craters: the Chicxulub in Mexico (>200 km diameter) and the Manson in Iowa (approximately 35 km diameter), both of which have 40Ar-39Ar ages of 65 Myr, indistinguishable from that of impact glass spherules found in K/T boundary sediments1-4. Here we report the strontium, neodymium and oxygen isotopic compositions of core samples of impact melt rock recovered from drill holes into both the Chicxulub and Manson craters, and compare these with previously published isotopic data for impact glasses from the K/T boundary of the Beloc Formation in Haiti5-7. The Chicxulub melt rocks are isotopically indistinguishable from the K/T impact glass, strongly supporting the proposition that Chicxulub is a source crater for the K/T catastrophe. The Manson melt rocks, by contrast, have a clearly different isotopic composition, strongly suggesting that they are unrelated to the K/T impact spherules.
C1 UNIV VIENNA, INST GEOCHEM, A-1010 VIENNA, AUSTRIA.
   Univ Nacl Autonoma Mexico, INST GEOFIS, MEXICO CITY 04510, MEXICO.
   LUNAR & PLANETARY INST, HOUSTON, TX 77058 USA.
C3 University of Vienna; Universidad Nacional Autonoma de Mexico
RP BLUM, JD (corresponding author), DARTMOUTH COLL, DEPT EARTH SCI, HANOVER, NH 03755 USA.
NR 24
TC 74
Z9 80
U1 0
U2 9
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 325
EP 327
DI 10.1038/364325a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000053
DA 2026-03-10
ER

PT J
AU BARBET, NC
   CARR, AM
AF BARBET, NC
   CARR, AM
TI FISSION YEAST WEE1 PROTEIN-KINASE IS NOT REQUIRED FOR DNA DAMAGE-DEPENDENT MITOTIC ARREST
SO NATURE
LA English
DT Article
ID schizosaccharomyces-pombe; cell-cycle; m-phase; mitosis; replication; division; mutants
AB CHECKPOINTS maintain the dependency relationships between discrete events in the cell cycle (for example, ensuring mitosis does not occur before DNA replication is complete)1,2. In Schizosaccharomyces pombe, mitotic checkpoints monitor DNA synthesis3 and the presence of DNA damage4,5. The replication-dependent mitotic checkpoint prevents mitosis by inactivating p34cdc2 kinase3. The mechanism by which the DNA damage checkpoint interacts with the mitotic machinery is distinct from that used by the replication checkpoint4,5. The activity of p34cdc is controlled, in part, by the wee 1 protein kinase6, which inactivates cdc2 through phosphorylation at tyrosine-15 (ref. 7). Here we report normal mitotic arrest after DNA damage in S. pombe cells in which the wee 1 gene is defective or missing. We suggest why these findings contradict a recent report8 which suggested that the wee1 gene product was required for DNA damage-dependent mitotic arrest.
C1 SUSSEX UNIV,MRC,CELL MUTAT UNIT,FALMER,BRIGHTON BN1 9RR,E SUSSEX,ENGLAND.
C3 University of Sussex
NR 14
TC 89
Z9 100
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 824
EP 827
DI 10.1038/364824a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100062
PM 8355807
DA 2026-03-10
ER

PT J
AU BRYAN, CD
   CORDES, AW
   FLEMING, RM
   GEORGE, NA
   GLARUM, SH
   HADDON, RC
   OAKLEY, RT
   PALSTRA, TTM
   PEREL, AS
   SCHNEEMEYER, LF
   WASZCZAK, JV
AF BRYAN, CD
   CORDES, AW
   FLEMING, RM
   GEORGE, NA
   GLARUM, SH
   HADDON, RC
   OAKLEY, RT
   PALSTRA, TTM
   PEREL, AS
   SCHNEEMEYER, LF
   WASZCZAK, JV
TI CONDUCTING CHARGE-TRANSFER SALTS BASED ON NEUTRAL PI-RADICALS
SO NATURE
LA English
DT Article
AB MOST molecular conductors rely on charge transfer to create carriers. For example, the ET salts1 are hole-doped whereas the C60 salts2 are electron-doped. Neutral radical species in which bands are formed by pi-orbital overlap would be expected to have half-filled bands and thus to be conducting3, but no such metals have yet been reported. Here we report the synthesis and characterization of a molecular conductor which combines both of these approaches: energy bands are formed from one-dimensional stacks of neutral pi-radicals, and the material is rendered conducting by electron transfer from the conduction band following doping with an acceptor. The radical species is the 1,4-phenylene-bis(dithiadiazolyl) diradical 1,4-[(S2N2C)C6H4(CN2S2)] (2 in Fig. 1), reaction of which with iodine vapour leads to crystals of [2][I]. At low temperatures this compound is essentially a diamagnetic insulator, but above 200 K the conductivity and magnetic susceptibility increase markedly, and at room temperature the conductivity reaches 100 S cm-1, which is comparable to that shown by conventional molecular charge-transfer salts.
C1 AT&T BELL LABS, MURRAY HILL, NJ 07974 USA.
   UNIV GUELPH, GUELPH WATERLOO CTR GRAD WORK CHEM, DEPT CHEM & BIOCHEM, GUELPH N1G 2W1, ONTARIO, CANADA.
C3 Nokia Corporation; Nokia Bell Labs; AT&T; University of Guelph; University of Waterloo; Guelph-Waterloo Centre for Graduate Work in Chemistry & Biochemistry
RP BRYAN, CD (corresponding author), UNIV ARKANSAS, DEPT CHEM & BIOCHEM, FAYETTEVILLE, AR 72701 USA.
NR 16
TC 85
Z9 94
U1 1
U2 14
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 821
EP 823
DI 10.1038/365821a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100044
DA 2026-03-10
ER

PT J
AU LORCA, T
   CRUZALEGUI, FH
   FESQUET, D
   CAVADORE, JC
   MERY, J
   MEANS, A
   DOREE, M
AF LORCA, T
   CRUZALEGUI, FH
   FESQUET, D
   CAVADORE, JC
   MERY, J
   MEANS, A
   DOREE, M
TI CALMODULIN-DEPENDENT PROTEIN KINASE-II MEDIATES INACTIVATION OF MPF AND CSF UPON FERTILIZATION OF XENOPUS EGGS
SO NATURE
LA English
DT Article
ID light chain kinase; protooncogene product; limited proteolysis; skeletal-muscle; meiotic arrest; activation; calcium; cyclin; degradation; oocytes
AB IN vertebrates, unfertilized eggs are arrested at second meiotic metaphase by a cytostatic factor (CSF)1, an essential component of which is the product of the c-mos proto-oncogene2. CSF prevents ubiquitin-dependent degradation of mitotic cyclins and thus inactivation of the M phase-promoting factor (MPF)3,4. Fertilization or parthenogenetic activation triggers a transient increase in the cytoplasmic free Ca2+ (reviewed in refs 5 and 6), inactivates both CSF and MPF, and releases eggs from meiotic metaphase arrest7-10. A calmodulin-dependent process is required for cyclin degradation to occur in cell-free extracts prepared from metaphase II-arrested eggs (CSF extracts) when the free Ca2+ concentration is transiently raised in the physiological micromolar range10. Here we show that when a constitutively active mutant of calmodulin-dependent protein kinase II (CaM K(II)) is added to a CSF extract, cyclin degradation and Cdc2 kinase inactivation occur even in the absence of Ca2+, and the extract loses its ability to cause metaphase arrest when transferred into embryos. Furthermore, specific inhibitors of CaM K(II) prevent cyclin degradation after calcium addition. Finally, the direct microinjection of constitutively active CaM K(II) into unfertilized eggs inactivates Cdc2 kinase and CSF, even in the absence of a Ca2+ transient. The target for Ca2+-calmodulin is thus CaM K(II).
C1 INSERM, F-34100 MONTPELLIER, FRANCE.
   BAYLOR COLL MED, DEPT CELL BIOL, HOUSTON, TX 77030 USA.
   DUKE UNIV, MED CTR, DEPT PHARMACOL, DURHAM, NC 27710 USA.
C3 Institut National de la Sante et de la Recherche Medicale (Inserm); Universite de Montpellier; Baylor College of Medicine; Duke University
RP LORCA, T (corresponding author), CNRS, BP 5051, F-34033 MONTPELLIER, FRANCE.
NR 29
TC 410
Z9 445
U1 0
U2 5
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 270
EP 273
DI 10.1038/366270a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500065
PM 8232587
DA 2026-03-10
ER

PT J
AU SRINIVASAN, MV
   ZHANG, SW
   ROLFE, B
AF SRINIVASAN, MV
   ZHANG, SW
   ROLFE, B
TI IS PATTERN VISION IN INSECTS MEDIATED BY CORTICAL PROCESSING
SO NATURE
LA English
DT Article
ID bees
AB IT is known that bees, like humans, can learn the orientation of a striped pattern, and recognize this orientation in other simple patterns that they have never previously encountered1,2. How is orientation analysed by the insect visual system? In the light of what is known about animal vision, there are two obvious possibilities. First, orientation could be determined purely in terms of the directional movement signals that the pattern generates as the bee approaches it or flies past it3,4. Such a scheme would fit in well with the common supposition that much of insect vision relies solely on motion cues4,5. An alternative view, not considered for insect vision so far, would be that specific features of the pattern, such as bars or edges, are extracted and their orientation analysed as in the mammalian cortex. Our findings argue strongly against the first and for the second possibility. They suggest that similar principles underlie the analysis of pattern orientation in insects and higher vertebrates.
RP SRINIVASAN, MV (corresponding author), AUSTRALIAN NATL UNIV, RES SCH BIOL SCI, CTR VISUAL SCI, POB 475, CANBERRA, ACT 2601, AUSTRALIA.
NR 17
TC 78
Z9 79
U1 0
U2 4
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 539
EP 540
DI 10.1038/362539a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300053
DA 2026-03-10
ER

PT J
AU STOUTHAMER, R
   BREEUWER, JAJ
   LUCK, RF
   WERREN, JH
AF STOUTHAMER, R
   BREEUWER, JAJ
   LUCK, RF
   WERREN, JH
TI MOLECULAR-IDENTIFICATION OF MICROORGANISMS ASSOCIATED WITH PARTHENOGENESIS
SO NATURE
LA English
DT Article
ID trichogramma hymenoptera; drosophila-simulans; incompatibility; populations; mormoniella
AB CYTOPLASMICALLY inherited microorganisms are widespread in insects and have been implicated as causes of female parthenogenesis (females developing from unfertilized eggs) and cytoplasmic incompatibility1-15. Normal sexual reproduction can be restored by treatment with antibiotics1-4. Sequence analysis of the DNA encoding 16S ribosomal RNA has shown that cytoplasmic incompatibility bacteria from diverse insect taxa are closely related (they share >95% sequence similarity) and belong to the alpha subdivision of Proteobacteria5-7. Here we show that parthenogenesis-associated bacteria from parasitoid Hymenoptera also fall into this bacterial group, having up to 99% sequence similarity to some incompatibility microorganisms. Both incompatibility and parthenogenesis microorganisms alter host chromosome behaviour during early mitotic divisions of the egg13-17. Incompatibility bacteria act by interfering with paternal chromosome incorporation in fertilized eggs, whereas parthenogenesis bacteria prevent segregation of chromosomes in unfertilized eggs. These traits are adaptive for the microorganisms. On the basis of their sequence similarities, we conclude that parthenogenesis bacteria and cytoplasmic incompatibility bacteria form a monophyletic group of microorganisms that 'specialize' in manipulating chromosome behaviour and reproduction of insects.
C1 UNIV CALIF RIVERSIDE,DEPT BIOL,RIVERSIDE,CA 92521.
   UNIV CALIF RIVERSIDE,DEPT ENTOMOL,RIVERSIDE,CA 92521.
C3 University of California System; University of California Riverside; University of California System; University of California Riverside
RP STOUTHAMER, R (corresponding author), AGR UNIV WAGENINGEN,DEPT ENTOMOL,POB 8031,6700 EH WAGENINGEN,NETHERLANDS.
NR 27
TC 419
Z9 489
U1 1
U2 68
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 66
EP 68
DI 10.1038/361066a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800049
PM 7538198
DA 2026-03-10
ER

PT J
AU SASSANFAR, M
   SZOSTAK, JW
AF SASSANFAR, M
   SZOSTAK, JW
TI AN RNA MOTIF THAT BINDS ATP
SO NATURE
LA English
DT Article
ID molecular recognition; receptor
AB RNAs that contain specific high-affinity binding sites for small molecule ligands immobilized on a solid support are present at a frequency of roughly one in 10(10)-10(11) in pools of random sequence RNA molecules1,2. Here we describe a new in vitro selection procedure designed to ensure the isolation of RNAs that bind the ligand of interest in solution as well as on a solid support. We have used this method to isolate a remarkably small RNA motif that binds ATP, a substrate in numerous biological reactions and the universal biological high-energy intermediate. The selected ATP-binding RNAs contain a consensus sequence, embedded in a common secondary structure. The binding properties of ATP analogues and modified RNAs show that the binding interaction is characterized by a large number of close contacts between the ATP and RNA, and by a change in the conformation of the RNA.
C1 MASSACHUSETTS GEN HOSP,DEPT MOLEC BIOL,BOSTON,MA 02114.
C3 Harvard University; Harvard University Medical Affiliates; Massachusetts General Hospital
RP SASSANFAR, M (corresponding author), HARVARD UNIV,SCH MED,DEPT GENET,BOSTON,MA 02115, USA.
NR 17
TC 533
Z9 661
U1 0
U2 92
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 550
EP 553
DI 10.1038/364550a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700062
PM 7687750
DA 2026-03-10
ER

PT J
AU RICHARDSON, SH
   HARRIS, JW
   GURNEY, JJ
AF RICHARDSON, SH
   HARRIS, JW
   GURNEY, JJ
TI 3 GENERATIONS OF DIAMONDS FROM OLD CONTINENTAL MANTLE
SO NATURE
LA English
DT Article
ID eclogitic diamonds; trace-element; inclusions; paragenesis; isotope; origin
AB INCLUSION-BEARING diamonds erupted by kimberlites are time capsules from the sub-continental mantle. Diamonds with peridotitic mineral inclusions ('peridotitic diamonds') from Cretaceous kimberlites in southern Africa have resided in stable mantle beneath the Kaapvaal craton since the Archaean1. Diamonds with eclogitic inclusions ('eclogitic diamonds') reflect episodic mantle events during the Proterozoic2,3. Here we discuss and present isotope data for a further category of diamonds from the Proterozoic Premier kimberlite, in which peridotitic inclusion minerals have compositions reflecting an origin in both harzburgitic (clinopyroxene-free) and lherzolitic (clinopyroxene-bearing) assemblages. The harzburgitic garnet inclusions and their counterparts found as isolated minerals ('macrocrysts') in the kimberlite host rock4 have neodymium and strontium isotope signatures consistent with an Archaean age (>3,000 Myr) and metasomatized mantle source. Lherzolitic garnet and clinopyroxene inclusions yield a preferred Sm-Nd isochron age of 1,930 Myr, which is approximately 100 Myr less than that of the adjacent Bushveld Complex5, suggesting a link analogous to that between harzburgitic diamond formation and komatiitic magmatism in the Archaean1. The final generation of diamonds, those with eclogitic inclusions, were formed approximately 1,150 Myr ago, just before kimberlite emplacement6.
C1 UNIV GLASGOW, DEPT GEOL & APPL GEOL, GLASGOW G12 8QQ, SCOTLAND.
C3 University of Glasgow
RP RICHARDSON, SH (corresponding author), UNIV CAPE TOWN, DEPT GEOL SCI, RONDEBOSCH 7700, SOUTH AFRICA.
NR 19
TC 139
Z9 151
U1 0
U2 20
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 256
EP 258
DI 10.1038/366256a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500060
DA 2026-03-10
ER

PT J
AU MARTIN, J
   GEROMANOS, S
   TEMPST, P
   HARTL, FU
AF MARTIN, J
   GEROMANOS, S
   TEMPST, P
   HARTL, FU
TI IDENTIFICATION OF NUCLEOTIDE-BINDING REGIONS IN THE CHAPERONIN PROTEINS GROEL AND GROES
SO NATURE
LA English
DT Article
ID escherichia-coli; atp hydrolysis; cooperativity; purification; f1-atpase; genes; site
AB THE chaperonin GroEL, a tetradecameric cylinder consisting of subunits of M(r) approximately 60,000 (60K), and its cofactor GroES, a heptameric ring of 10K subunits, mediate protein folding in the cytosol of Escherichia coli1-3. In the presence of nucleotide, GroES forms a 1:1 complex with GroEL which binds unfolded protein in its central cavity and releases it to allow folding upon ATP hydrolysis4-7. Using labelling with azido-ATP, we have identified a protease-stable nucleotide-binding domain of M(r) 40K in the GroEL subunits (residues 153-531). Azido-ATP is crosslinked to the highly conserved Tyr 477, indicating that this residue is close to the purine ring of the bound nucleotide. Surprisingly, GroES also binds ATP cooperatively and with an affinity comparable to that of GroEL. Azido-nucleotide labelling of GroES subunits occurs at the conserved Tyr 71 in a protease-stable 6.5K domain (starting at residue 33). Proteinase K cleavage at residue 32 is prevented when GroES is bound to GroEL. ATP binding to GroES may be important in charging the seven subunits of the interacting GroEL ring with ATP to facilitate cooperative ATP binding and hydrolysis for substrate protein release.
C1 MEM SLOAN KETTERING CANC CTR,CELLULAR BIOCHEM & BIOPHYS PROGRAM,1275 YORK AVE,NEW YORK,NY 10021.
   MEM SLOAN KETTERING CANC CTR,MOLEC BIOL PROGRAM,NEW YORK,NY 10021.
C3 Memorial Sloan Kettering Cancer Center; Memorial Sloan Kettering Cancer Center
NR 29
TC 94
Z9 104
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 279
EP 282
DI 10.1038/366279a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500068
PM 7901771
DA 2026-03-10
ER

PT J
AU SOBOLEV, AV
   SHIMIZU, N
AF SOBOLEV, AV
   SHIMIZU, N
TI ULTRA-DEPLETED PRIMARY MELT INCLUDED IN AN OLIVINE FROM THE MID-ATLANTIC RIDGE
SO NATURE
LA English
DT Article
ID oceanic-crust; upper mantle; petrogenesis
AB MODELS of magma genesis at mid-ocean ridges1, together with recent experimental data2 and observations of trace element abundances in clinopyroxenes from abyssal peridotites3, suggest that small-volume melt fractions can be efficiently extracted from the melting mantle. As shown in ref. 3, residues of this type of melting (fractional melting) display extremely low abundances of incompatible trace elements and extreme fractionation amongst them, especially at advanced stages of the process because of the compounded effects of differences in the partition coefficients. If this process operates beneath mid-ocean ridges, one would expect to sample melts that are correspondingly depleted and fractionated in trace elements. Indeed, the existence of very depleted melts in mid-ocean ridges was predicted previously4-6 in order to explain the presence of magnesian pyroxene and calcic plagioclase in mid-ocean-ridge basalts. We report here the discovery of melt that has major and trace element characteristics consistent with these predictions4-6, occurring as an inclusion in an olivine phenocryst in a typical mid-ocean-ridge basalt from the Mid-Atlantic Ridge. Although our preferred model for the origin of this 'ultra-depleted' melt is critical (continuous) melting, we cannot at this stage rule out other models. Our results underscore the importance ot trapped melt inclusions as recorders of the processes involved in melting and melt extraction, and also as pointers to primary melt compositions.
C1 WOODS HOLE OCEANOG INST, DEPT GEOL & GEOPHYS, WOODS HOLE, MA 02543 USA.
C3 Woods Hole Oceanographic Institution
RP SOBOLEV, AV (corresponding author), VI VERNADSKY GEOCHEM INST, KOSIGIN STR 19, MOSCOW 117975, RUSSIA.
NR 20
TC 353
Z9 394
U1 2
U2 48
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 151
EP 154
DI 10.1038/363151a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100044
DA 2026-03-10
ER

PT J
AU MACFARLANE, DE
   DAHLE, CE
AF MACFARLANE, DE
   DAHLE, CE
TI ISOLATING RNA FROM WHOLE-BLOOD - THE DAWN OF RNA-BASED DIAGNOSIS
SO NATURE
LA English
DT Article
ID polymerase chain-reaction; bone-marrow transplantation; leukemia patients
C1 UNIV IOWA,IOWA BIOTECHNOL CORP,INST TECHNOL INNOVAT,IOWA CITY,IA 52242.
C3 University of Iowa
RP MACFARLANE, DE (corresponding author), UNIV IOWA,DEPT INTERNAL MED,IOWA CITY,IA 52242, USA.
NR 16
TC 49
Z9 60
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 186
EP 188
DI 10.1038/362186a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800069
PM 7680772
DA 2026-03-10
ER

PT J
AU SUMMERS, DP
   CHANG, S
AF SUMMERS, DP
   CHANG, S
TI PREBIOTIC AMMONIA FROM REDUCTION OF NITRITE BY IRON(II) ON THE EARLY EARTH
SO NATURE
LA English
DT Article
ID aqueous-solution; carbon-dioxide; atmosphere; evolution; nitrogen; fixation; seawater; impacts; oxygen; sulfur
AB THEORIES for the origin of life require the availability of reduced (or 'fixed') nitrogen-containing compounds, in particular ammonia. In reducing atmospheres, such compounds are readily formed by electrical discharges1-2, but geochemical evidence suggests that the early Earth had a non-reducing atmosphere1,3-6, in which discharges would have instead produced NO (refs 7-10). This would have been converted into nitric and nitrous acids and delivered to the early oceans as acid rain11. It is known12-15, however, that Fe(II) was present in the early oceans at much higher concentrations than are found today, and thus the oxidation of Fe(II) to Fe(III) provides a possible means for reducing nitrites and nitrates to ammonia. Here we explore this possibility in a series of experiments which mimic a broad range of prebiotic seawater conditions (the actual conditions on the early Earth remain poorly constrained). We find that the reduction by Fe(II) of nitrites and nitrates to ammonia could have been a significant source of reduced nitrogen on the early Earth, provided that the ocean pH exceeded 7.3 and is favoured for temperatures greater than about 25-degrees-C.
RP SUMMERS, DP (corresponding author), NASA,AMES RES CTR,MOFFETT FIELD,CA 94035, USA.
NR 31
TC 158
Z9 174
U1 1
U2 74
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 630
EP 632
DI 10.1038/365630a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600053
PM 11540245
DA 2026-03-10
ER

PT J
AU KANAMORI, H
   KIKUCHI, M
AF KANAMORI, H
   KIKUCHI, M
TI THE 1992 NICARAGUA EARTHQUAKE - A SLOW TSUNAMI EARTHQUAKE ASSOCIATED WITH SUBDUCTED SEDIMENTS
SO NATURE
LA English
DT Article
ID source mechanism; trenches; event
AB THE 1992 Nicaragua earthquake was a 'tsunami earthquake'; that is, it generated tsunamis1 disproportionately large for its surface-wave magnitude, M(s). The moment magnitude, M(w), determined from long-period (approximately 250-s) surface waves2, was 7.6, significantly larger than the 20-s M(s) of 7; this M(s)-M(w) disparity is also characteristic of tsunami earthquakes3,4. The Nicaragua earthquake is the first tsunami earthquake to be captured by modern broadband seismic networks, allowing us to present here seismograms of sufficiently high quality to make inferences about the rupture mechanisms. We conclude that the Nicaragua earthquake was a slow thrust earthquake which occurred on the subduction interface between the Cocos and North American plates, and because of the absence of sediments on the trench floor offshore of Nicaragua, the slip propagated up-dip all the way to the ocean bottom, exciting large tsunamis. The occurrence of slip on a plate interface filled with soft subducted sediments caused the rupture process to be slower than in ordinary subduction-zone thrust earthquakes. Our results reinforce the idea that tsunami warning systems using long-period (greater-than-or-equal-to 100-s) waves5-7 are necessary to reduce the hazard from this type of earthquake.
C1 YOKOHAMA CITY UNIV,DEPT PHYS,YOKOHAMA 236,JAPAN.
C3 Yokohama City University
RP KANAMORI, H (corresponding author), CALTECH,SEISMOL LAB,PASADENA,CA 91125, USA.
NR 23
TC 279
Z9 315
U1 0
U2 171
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 714
EP 716
DI 10.1038/361714a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900052
DA 2026-03-10
ER

PT J
AU MAROTTI, KR
   CASTLE, CK
   BOYLE, TP
   LIN, AH
   MURRAY, RW
   MELCHIOR, GW
AF MAROTTI, KR
   CASTLE, CK
   BOYLE, TP
   LIN, AH
   MURRAY, RW
   MELCHIOR, GW
TI SEVERE ATHEROSCLEROSIS IN TRANSGENIC MICE EXPRESSING SIMIAN CHOLESTERYL ESTER TRANSFER PROTEIN
SO NATURE
LA English
DT Article
ID density-lipoprotein levels; plasma; susceptibility; strains; lesions; fat
AB CHOLESTERYL ester transfer protein (CETP) is a plasma protein that mediates the exchange of neutral lipids among the lipoproteins1-3. Because the principal core lipid of very-low-density lipoprotein (VLDL) is triglyceride and that of high-density lipoprotein (HDL) is cholesterol ester, CETP mediates a 'heteroexchange' of cholesterol ester for triglyceride between those lipoproteins. As a result, animals that express CETP tend to have higher VLDL and low-density lipoprotein (LDL) cholesterol levels, whereas those with no CETP activity tend to have high HDL cholesterol levels2. Because VLDL and LDL are associated with the progression of atherosclerosis, and HDL are considered anti-atherogenic, CETP could be an 'atherogenic' protein, that is, given the other conditions required for atherosclerosis to develop, expression of CETP would accelerate the rate at which the arterial lesions progress. We report here that transgenic mice expressing CETP had much worse atherosclerosis than did non-expressing controls, and we suggest that the increase in lesion severity was due largely to CETP-induced alterations in the lipoprotein profile.
RP MAROTTI, KR (corresponding author), UPJOHN CO LABS,MOLEC BIOL RES & METAB DIS RES,7242-209-7,KALAMAZOO,MI 49001, USA.
NR 12
TC 425
Z9 442
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 73
EP 75
DI 10.1038/364073a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800061
PM 8316302
DA 2026-03-10
ER

PT J
AU NAKAI, N
   INOUE, M
   MIYOSHI, M
AF NAKAI, N
   INOUE, M
   MIYOSHI, M
TI EXTREMELY-HIGH-VELOCITY H2O MASER EMISSION IN THE GALAXY NGC4258
SO NATURE
LA English
DT Article
ID resolution radio observations; ngc 4258; ngc-4258; vla
AB WATER-VAPOUR maser emission at 22.23508 GHz has been observed in star-forming regions of our own galaxy and in the active nuclei of other galaxies1-5. Maser emission from active galactic nuclei is typically 10(5) times more luminous than in our galaxy, and the active galaxies concerned always exhibit radio or optical jets ejected from the nuclei. The superluminous masers are not well understood, but appear to be related to the mass outflow6. Using 16,000-channel spectrometers at the Nobeyama 45-m radio telescope, we have found H2O maser emission in the nucleus of the galaxy NGC4258, offset by +/- 1,000 km s-1 from the motion of the nucleus itself. This is much higher than the typical velocities of galactic masers (less than a few hundred kilometres per second). We suggest that the high-velocity maser emission in NGC4258 might be from masers orbiting a massive central black hole, or ejected in a bipolar outflow. More intriguingly, the features may not be Doppler in origin, but due to up- and down-shifted frequencies by Raman scattering in a dense plasma. Further high-resolution observations will be needed to distinguish between these possibilities.
RP NAKAI, N (corresponding author), NOBEYAMA RADIO OBSERV,MINAMISA KU,NAGANO 38413,JAPAN.
NR 21
TC 109
Z9 112
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 45
EP 47
DI 10.1038/361045a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800040
DA 2026-03-10
ER

PT J
AU MCDONNELL, JAM
   MCBRIDE, N
   BEARD, R
   BUSSOLETTI, E
   COLANGELI, L
   EBERHARDT, P
   FIRTH, JG
   GRARD, R
   GREEN, SF
   GREENBERG, JM
   GRUN, E
   HUGHES, DW
   KELLER, HU
   KISSEL, J
   LINDBLAD, BA
   MANDEVILLE, JC
   PERRY, CH
   REMBOR, K
   RICKMAN, H
   SCHWEHM, GH
   TURNER, RF
   WALLIS, MK
   ZARNECKI, JC
AF MCDONNELL, JAM
   MCBRIDE, N
   BEARD, R
   BUSSOLETTI, E
   COLANGELI, L
   EBERHARDT, P
   FIRTH, JG
   GRARD, R
   GREEN, SF
   GREENBERG, JM
   GRUN, E
   HUGHES, DW
   KELLER, HU
   KISSEL, J
   LINDBLAD, BA
   MANDEVILLE, JC
   PERRY, CH
   REMBOR, K
   RICKMAN, H
   SCHWEHM, GH
   TURNER, RF
   WALLIS, MK
   ZARNECKI, JC
TI DUST PARTICLE IMPACTS DURING THE GIOTTO ENCOUNTER WITH COMET GRIGG-SKJELLERUP
SO NATURE
LA English
DT Article
AB IN the European Space Agency's 1992 Giotto Extended Mission, the Dust Impact Detection System operated successfully during a fly-by that took the spacecraft within about 200 km of the nucleus of comet Grigg-Skjellerup. During the encounter, three meteoroid impacts were detected on Giotto's front shield. The particle masses were found to be 100(-50)+105 mug, 2(-1)+4 mug and 20(-10)+25 mug, suggesting that the mass distribution of the cometary dust was dominated by larger particles. This is supported by the independent detection of a very large meteoroid (14(-4)+40 mg) by the Giotto Radio-Science Experiment, and is consistent with data over the same mass range from the 1986 encounter with comet Halley. The results indicate a higher rate of mass loss from the nucleus than previously thought, and hence a higher dust-to-gas mass ratio.
C1 IST UNIV NAVALE, IST FIS SPERIMENTALE, I-80133 NAPLES, ITALY.
   UNIV CASSINO, I-03043 CASSINO, ITALY.
   UNIV BERN, INST PHYS, CH-3012 BERN, SWITZERLAND.
   RUTHERFORD APPLETON LAB, DEPT SPACE SCI, DIDCOT OX11 0QX, OXON, ENGLAND.
   ESTEC, PSS, 2200 AG NOORDWIJK, NETHERLANDS.
   LEIDEN UNIV, HUYGENS LAB, 2300 RA LEIDEN, NETHERLANDS.
   MAX PLANCK INST NUCL PHYS, W-6900 HEIDELBERG 1, GERMANY.
   UNIV SHEFFIELD, DEPT PHYS, SHEFFIELD S3 7RH, S YORKSHIRE, ENGLAND.
   MAX PLANCK INST AERON, W-3411 KATLENBURG DUHM, GERMANY.
   LUND OBSERV, S-22100 LUND, SWEDEN.
   OFF NATL ETUD & RECH AEROSP, CERT, DERTS, F-31055 TOULOUSE, FRANCE.
   ASTRON OBSERV, S-75120 UPPSALA, SWEDEN.
   UNIV KARLSRUHE, FAK PHYS, W-7500 KARLSRUHE, GERMANY.
   UNIV WALES COLL CARDIFF, SCH MATH, CARDIFF CF2 4AG, WALES.
C3 University of Naples Federico II; University of Cassino; University of Bern; UK Research & Innovation (UKRI); Science & Technology Facilities Council (STFC); STFC Rutherford Appleton Laboratory; European Space Agency; European Space Research & Technology Centre; Leiden University - Excl LUMC; Leiden University; Max Planck Society; University of Sheffield; Max Planck Society; Lund University; National Office for Aerospace Studies & Research (ONERA); Helmholtz Association; Karlsruhe Institute of Technology; Cardiff University
RP MCDONNELL, JAM (corresponding author), UNIV KENT, PHYS LAB, SPACE SCI UNIT, CANTERBURY CT2 7NR, KENT, ENGLAND.
NR 5
TC 59
Z9 60
U1 0
U2 4
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 732
EP 734
DI 10.1038/362732a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000049
DA 2026-03-10
ER

PT J
AU ANGERT, ER
   CLEMENTS, KD
   PACE, NR
AF ANGERT, ER
   CLEMENTS, KD
   PACE, NR
TI THE LARGEST BACTERIUM
SO NATURE
LA English
DT Article
ID ribosomal-rna; gut; surgeonfishes; acanthuridae; reef; sea; dna
AB THE large, morphologically peculiar microorganism Epulopiscium fishelsoni1,2 inhabits the intestinal tract of Acanthurus nigrofuscus, a brown surgeonfish (family Acanthuridae) from the Red Sea. Similar microorganisms have been found in surgeonfish species from the Great Barrier Reef3. As these microorganisms have only been seen in surgeonfish and no free-living forms have been found, they are considered to be specific symbionts of surgeonfish, although the nature of the symbiosis is unclear1-4 . Initial reports considered them to be eukaryotic protists, based primarily on their size1-4, with individuals being larger than 600 mum by 80 mum. But their cellular morphology in the electron microscope is more like that of bacterial than eukaryotic cells1,2,5. To resolve the nature of these symbionts, we have isolated the genes encoding the small subunit ribosomal RNA from two morphotypes and used them in a phylogenetic analysis. In situ hybridization with oligonucleotide probes based on the cloned rRNA sequences confirmed the source of the rRNA genes. Our results identify the symbionts as members of the low-(G + C) Gram-positive group of bacteria. They are therefore the largest bacteria to be described so far.
C1 INDIANA UNIV, DEPT BIOL, BLOOMINGTON, IN 47405 USA.
   JAMES COOK UNIV N QUEENSLAND, DEPT MARINE BIOL, TOWNSVILLE, QLD 4811, AUSTRALIA.
C3 Indiana University System; Indiana University Bloomington; James Cook University
NR 19
TC 148
Z9 167
U1 0
U2 35
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 239
EP 241
DI 10.1038/362239a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600054
PM 8459849
DA 2026-03-10
ER

PT J
AU MICHALEK, MT
   GRANT, EP
   GRAMM, C
   GOLDBERG, AL
   ROCK, KL
AF MICHALEK, MT
   GRANT, EP
   GRAMM, C
   GOLDBERG, AL
   ROCK, KL
TI A ROLE FOR THE UBIQUITIN-DEPENDENT PROTEOLYTIC PATHWAY IN MHC CLASS I-RESTRICTED ANTIGEN PRESENTATION
SO NATURE
LA English
DT Article
ID toxic lymphocytes-t; activating enzyme; molecules; expression; degradation; protein; icam-1; cells; gene; e1
AB THE degradation of most cellular proteins starts with their covalent conjugation with ubiquitin1,2. This labels the proteins for rapid hydrolysis to oligopeptides by a (26S) proteolytic complex containing a (20S) degradative particle called the proteasome3,4. Some system in the cytosol also generates antigenic peptides from endogenously synthesized cellular and viral proteins5-10. These peptides bind to newly synthesized class I major histocompatibility complex molecules in the endoplasmic reticulum and peptide/class I complexes are then transported to the cell surface for presentation to cytotoxic T cells11,12. How these peptides are produced is unknown, although a modification that promotes ubiquitin-dependent degradation of a viral protein enhances its presentation with class I13 and indirect evidence suggests a role for proteolytic particles closely resembling and perhaps identical to the proteasome4,12,14,15. Using cells that exhibit a temperature-sensitive defect in ubiquitin conjugation, we report here that nonpermissive temperature inhibited class I-restricted presentation of ovalbumin introduced into the cytosol, but did not affect presentation of an ovalbumin peptide synthesized from a minigene. These results implicate the ubiquitin-dependent proteolytic pathway in the production of antigenic peptides.
C1 HARVARD UNIV, SCH MED, DEPT PATHOL, BOSTON, MA 02115 USA.
   HARVARD UNIV, SCH MED, DEPT CELLULAR & MOLEC PHYSIOL, BOSTON, MA 02115 USA.
C3 Harvard University; Harvard Medical School; Harvard University; Harvard Medical School
RP MICHALEK, MT (corresponding author), HARVARD UNIV, SCH MED, DANA FARBER CANC INST, DIV LYMPHOCYTE BIOL, BOSTON, MA 02115 USA.
NR 37
TC 319
Z9 364
U1 0
U2 8
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 552
EP 554
DI 10.1038/363552a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900053
PM 8389422
DA 2026-03-10
ER

PT J
AU STEEL, MA
   LOCKHART, PJ
   PENNY, D
AF STEEL, MA
   LOCKHART, PJ
   PENNY, D
TI CONFIDENCE IN EVOLUTIONARY TREES FROM BIOLOGICAL SEQUENCE DATA
SO NATURE
LA English
DT Article
ID influenza-virus; genome; origins; genes
AB THE reliable construction of evolutionary trees from nucleotide sequences often depends on randomization tests such as the boot-strap1 and PTP (cladistic permutation tail probability) tests2-6. The genomes of bacteria7, viruses8, animals7,9,10 and plants11, however, vary widely in their nucleotide frequencies. Where genomes have independently acquired similar G+C base compositions, signals in the data arise that cause methods of evolutionary tree reconstruction to estimate the wrong tree by grouping together sequences with similar G+C content12-14. Under these conditions randomization tests can lead to both the rejection of the correct evolutionary hypothesis and acceptance of an incorrect hypothesis (such as with the contradictory inferences from the photosynthetic rbcS and rbcL sequences14). We have proposed one approach to testing for the G+C content problem15. Here we present a formalization of this method, a frequency-dependent significance test, which has general application.
C1 MASSEY UNIV,MOLEC GENET UNIT,PALMERSTON NORTH,NEW ZEALAND.
C3 Massey University
RP STEEL, MA (corresponding author), MASSEY UNIV,DEPT MATH,PALMERSTON NORTH,NEW ZEALAND.
NR 18
TC 151
Z9 161
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 440
EP 442
DI 10.1038/364440a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000053
PM 8332213
DA 2026-03-10
ER

PT J
AU LI, R
   HAVEL, C
   WATSON, JA
   MURRAY, AW
AF LI, R
   HAVEL, C
   WATSON, JA
   MURRAY, AW
TI THE MITOTIC FEEDBACK-CONTROL GENE MAD2 ENCODES THE ALPHA-SUBUNIT OF A PRENYLTRANSFERASE
SO NATURE
LA English
DT Article
ID protein transferases; ras protein; yeast; ypt1; attachment; transport; mechanism; homology; invitro; mutants
AB THE mad2-1 mutation inactivates the cell-cycle feedback control that prevents budding yeast cells from leaving mitosis until spindle assembly is complete1. The gene product of MAD2 shows significant sequence similarity to the alpha-subunit of prenyltransferases2. Here we isolate a new temperature-sensitive mad2 mutant, mad2-2ts, and find that Mad2p is required for the membrane association of Ypt1p and Sec4p, two prenylated small GTP-binding proteins involved in protein trafficking. Extracts from mad2-2ts mutant cells fail to geranylgeranylate a number of substrates at the non-permissive temperature. mad2-2ts is synthetically lethal with bet2-1, a mutation in the gene that encodes for the beta-subunit of the Ypt1p and Sec4p geranylgeranyl transferase3,4. Therefore MAD2 and BET2 gene products may physically interact to form a geranylgeranyl transferase complex. In addition, the difference between the phenotypes of mad2-1 and mad2-2ts suggests that MAD2 has distinct roles in protein transport and the mitotic feedback control.
C1 UNIV CALIF SAN FRANCISCO,DEPT BIOCHEM,SAN FRANCISCO,CA 94143.
   UNIV CALIF SAN FRANCISCO,DEPT PHYSIOL,SAN FRANCISCO,CA 94143.
C3 University of California System; University of California San Francisco; University of California System; University of California San Francisco
NR 21
TC 42
Z9 47
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 82
EP 84
DI 10.1038/366082a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700060
PM 8232541
DA 2026-03-10
ER

PT J
AU TAGLE, DA
   SWAROOP, M
   LOVETT, M
   COLLINS, FS
AF TAGLE, DA
   SWAROOP, M
   LOVETT, M
   COLLINS, FS
TI MAGNETIC BEAD CAPTURE OF EXPRESSED SEQUENCES ENCODED WITHIN LARGE GENOMIC SEGMENTS
SO NATURE
LA English
DT Article
ID transcribed sequences; selection; gene; dna
C1 UNIV MICHIGAN,MED CTR,DEPT INTERNAL MED,ANN ARBOR,MI 48109.
   UNIV TEXAS,SW MED CTR,DEPT BIOCHEM,DALLAS,TX 75235.
C3 University of Michigan System; University of Michigan; University of Texas System; University of Texas Southwestern Medical Center; University of Texas Dallas
RP TAGLE, DA (corresponding author), UNIV MICHIGAN,MED CTR,DEPT HUMAN GENET,ANN ARBOR,MI 48109, USA.
NR 21
TC 84
Z9 99
U1 0
U2 18
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 751
EP 753
DI 10.1038/361751a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900065
PM 8441473
DA 2026-03-10
ER

PT J
AU KAMBARA, H
   TAKAHASHI, S
AF KAMBARA, H
   TAKAHASHI, S
TI MULTIPLE-SHEATHFLOW CAPILLARY ARRAY DNA ANALYZER
SO NATURE
LA English
DT Article
ID electrophoresis
RP KAMBARA, H (corresponding author), HITACHI LTD,CENT RES LAB,KOKUBUNJI,TOKYO 185,JAPAN.
NR 12
TC 134
Z9 154
U1 0
U2 17
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 565
EP 566
DI 10.1038/361565a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400073
PM 8429915
DA 2026-03-10
ER

PT J
AU UEMURA, YJ
   KEREN, A
   LE, LP
   LUKE, GM
   WU, WD
   KUBO, Y
   MANAKO, T
   SHIMAKAWA, Y
   SUBRAMANIAN, M
   COBB, JL
   MARKERT, JT
AF UEMURA, YJ
   KEREN, A
   LE, LP
   LUKE, GM
   WU, WD
   KUBO, Y
   MANAKO, T
   SHIMAKAWA, Y
   SUBRAMANIAN, M
   COBB, JL
   MARKERT, JT
TI MAGNETIC-FIELD PENETRATION DEPTH IN TL2BA2CUO6+DELTA IN THE OVERDOPED REGIME
SO NATURE
LA English
DT Article
ID ii superconductors; tc; transport; cuprate
AB THE magnetic field penetration depth lambda is a basic parameter of superconductivity, related to n(s)/m* (superconducting carrier density/effective mass) as lambda-2 is-proportional-to n(s)/m* in the limit where the coherence length xi is much shorter than the mean free path l (the 'clean limit'). Muon spin relaxation (muSR) measurements1,2 of lambda in high-transition-temperature (high-T(c)) copper oxide superconductors have revealed remarkable correlations between T(c) and n(s)/m*: T(c) increases linearly with n(s)/m* in the underdoped region, followed by a saturation with increasing carrier doping. Here we report muSR measurements of lambda in ceramic specimens of the superconductor Tl2Ba2CuO6+delta (Tl-2201) in the 'overdoped' region where T(c) decreases with increasing hole doping. Recent measurements of upper critical field and resistivity3 confirm that overdoped Tl-2201 lies well in the clean limit with xi << L We find that the muon spin relaxation rate sigma(T --> 0) is-proportional-to lambda-2 is-proportional-to n(s)/m* in Tl-2201 decreases with increasing hole doping, implying that either n(s) no longer scales with the normal-state carrier density n(n), and/or m* for a superconducting pair becomes much larger than the value expected from the normal-state effective mass m(n)*. This behaviour of overdoped Tl-2201 is in marked contrast to conventional metallic superconductors having a retarded interaction, in which the normal-state properties (n(n), m(n)*, l) directly represent the corresponding values in the superconducting state.
C1 NEC CORP LTD,FUNDAMENTAL RES LAB,TSUKUBA,IBARAKI 305,JAPAN.
   DUPONT CO INC,EXPTL STN,WILMINGTON,DE 19880.
   UNIV TEXAS,DEPT PHYS,AUSTIN,TX 78712.
C3 NEC Corporation; DuPont; DuPont USA; University of Texas System; University of Texas Austin
RP UEMURA, YJ (corresponding author), COLUMBIA UNIV,DEPT PHYS,NEW YORK,NY 10027, USA.
NR 19
TC 225
Z9 231
U1 3
U2 49
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 605
EP 607
DI 10.1038/364605a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100045
DA 2026-03-10
ER

PT J
AU CLARK, MM
   KARPIUK, P
   GALEF, BG
AF CLARK, MM
   KARPIUK, P
   GALEF, BG
TI HORMONALLY MEDIATED INHERITANCE OF ACQUIRED CHARACTERISTICS IN MONGOLIAN GERBILS
SO NATURE
LA English
DT Article
ID adult female mice; intrauterine position; uterine position; sexual-behavior; fetuses; rats; morphology; contiguity; androgen; uterus
AB THE intrauterine position relative to members of the same or opposite sex that a rodent fetus occupies affects both its morphology and behaviour when adult1-14. Female fetuses that mature between males are androgenized by testosterone crossing fetal membranes15,16, and their phenotypes as adults differ significantly from those of sisters that received less intrauterine exposure to exogenous testosterone17-20. We report here that adult female Mongolian gerbils that gestated between male fetuses produce litters containing a significantly greater proportion of sons than the litters produced by those that gestated between female fetuses. Consequently, daughters delivered by dams that gestated between male fetuses are more likely to have gestated between male fetuses and be androgenized in utero than are daughters of dams that gestated between female fetuses. Female gerbils thus tend to inherit the phenotype (either androgenized or not androgenized) of their respective mothers.
RP CLARK, MM (corresponding author), MCMASTER UNIV,DEPT PSYCHOL,HAMILTON L8S 4K1,ONTARIO,CANADA.
NR 25
TC 103
Z9 108
U1 1
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 712
EP 712
DI 10.1038/364712a0
PG 1
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700055
PM 8355782
DA 2026-03-10
ER

PT J
AU RAYMOND, LA
   BLACKSTONE, CD
   HUGANIR, RL
AF RAYMOND, LA
   BLACKSTONE, CD
   HUGANIR, RL
TI PHOSPHORYLATION AND MODULATION OF RECOMBINANT GLUR6 GLUTAMATE RECEPTORS BY CAMP-DEPENDENT PROTEIN-KINASE
SO NATURE
LA English
DT Article
ID retinal horizontal cells; amino-acid receptors; hippocampal-neurons; nervous-system; kainate; enhancement; quisqualate; activation
AB GLUTAMATE-GATED ion channels mediate most excitatory synaptic transmission in the central nervous system and play crucial roles in synaptic plasticity, neuronAL development and some neuropathological conditions1-3. These ionotropic glutamate receptors have been classified according to their preferred agonists as NMDA (N-methyL-D-aspartate), AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate) and KA (kainate) receptors4. On the basis of sequence similarity and pharmacological properties, the recently cloned glutamate receptor subunits have been assigned as components of NMDA (NMDAR1, 2A-D), AMPA (GluR1-4) and KA (GluR5-7, KA1, KA2) receptors5-7. Protein phosphorylation of glutamate receptors by protein kinase C and cyclic AMP-dependent protein kinase (PKA) has been suggested to regulate their function8-18, possibly playing a prominent role in certain forms of synaptic plasticity such as long-term potentiation19 and long-term depression9. Here we report that the GluR6 glutamate receptor, transiently expressed in mammalian cells, is directly phosphorylated by PKA, and that intracellularly applied PKA increases the amplitude of the glutamate response. Site-specific mutagenesis of the serine residue (Ser 684) representing a PKA consensus site completely eliminates PKA-mediated phosphorylation of this site as well as the potentiation of the glutamate response. These results provide evidence that direct phosphorylation of glutamate receptors modulates their function.
C1 JOHNS HOPKINS UNIV,SCH MED,HOWARD HUGHES MED INST,DEPT NEUROL,BALTIMORE,MD 21205.
C3 Johns Hopkins University; Howard Hughes Medical Institute
NR 29
TC 254
Z9 265
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 637
EP 641
DI 10.1038/361637a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600064
PM 8094892
DA 2026-03-10
ER

PT J
AU KORPI, ER
   KLEINGOOR, C
   KETTENMANN, H
   SEEBURG, PH
AF KORPI, ER
   KLEINGOOR, C
   KETTENMANN, H
   SEEBURG, PH
TI BENZODIAZEPINE-INDUCED MOTOR IMPAIRMENT LINKED TO POINT MUTATION IN CEREBELLAR GABA(A) RECEPTOR
SO NATURE
LA English
DT Article
ID ant rat line; <h-3>ro 15-4513; plasmid dna; cells; sensitivity; channels; binding; inverse; brain
AB THE selectively outbred alcohol-non-tolerant (ANT) rat line1 is highly susceptible to impairment of postural reflexes by benzodiazepine agonists2 such as diazepam. ANT cerebella are generally devoid3 of diazepam-insensitive high-affinity binding of the benzodiazepine [H-3]Ro15-4513 (refs 4, 5), whereas in non-selected strains such binding marks a granule-cell-specific GABA(A) (gamma-aminobutyric acid) receptor containing the alpha6 subunit5,6. A critical determinant for diazepam insensitivity of this 'wild-type' cerebellar GABA(A) receptor is an arginine residue7 in alpha6 position 100, where other alpha subunits carry a histidine8. Here we report that the alpha6 gene of ANT rats is expressed at wild-type levels but carries a point mutation generating an arginine-to-glutamine substitution at position 100. In consequence, alpha6(Q100)beta2gamma2 receptors show diazepam-mediated potentiation of GABA-activated currents and diazepam-sensitive binding of [H-3]Ro15-4513. Our results suggest that cerebellar motor control may be a distinct behavioural correlate of the alpha6-subunit-containing GABA(A) receptor subtype.
C1 ALKO LTD,BIOMED RES CTR,SF-00101 HELSINKI,FINLAND.
   UNIV HEIDELBERG,DEPT NEUROBIOL,W-6900 HEIDELBERG,GERMANY.
C3 Ruprecht Karls University Heidelberg
RP KORPI, ER (corresponding author), UNIV HEIDELBERG,CTR MOLEC BIOL,MOLEC NEUROENDOCRINOL LAB,NEUENHEIMER FELD 282,W-6900 HEIDELBERG,GERMANY.
NR 24
TC 223
Z9 235
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 356
EP 359
DI 10.1038/361356a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000059
PM 7678923
DA 2026-03-10
ER

PT J
AU GUARIGLIA, C
   PADOVANI, A
   PANTANO, P
   PIZZAMIGLIO, L
AF GUARIGLIA, C
   PADOVANI, A
   PANTANO, P
   PIZZAMIGLIO, L
TI UNILATERAL NEGLECT RESTRICTED TO VISUAL-IMAGERY
SO NATURE
LA English
DT Article
ID cerebral hemispheres; mental-imagery; space
AB DISORDERS in perceiving and exploring the visual space contralateral to a brain lesion have been frequently described. Many patients with hemi-neglect for extrapersonal space also show neglect in a representational domain when the task requires imagining a well-known piazza from a given vantage point1,2 or comparing two visual images3-5. Cognitive6 and psychophysiological7 studies show a functional parallelism between the perceptual and imaginative domain7, indicating that spatial perception and imagery share the same neural substrata. Here we describe a patient with a persistent disorder in visual imagery for familiar piazzas in the absence of any neglect for stimuli located in a far8 or near9 space or on his own body10. Contrary to previous cases involving imagery disorders, computerized tomography scans showed a lesion confined to the right frontal lobe, suggesting the role of the frontal lobe in some specific types of mental imagery.
C1 UNIV ROMA LA SAPIENZA,DEPT PSYCHOL,VIA MARSI 78,I-00185 ROME,ITALY.
   UNIV ROMA LA SAPIENZA,DEPT NEUROL,I-00185 ROME,ITALY.
   CLIN S LUCIA,I-00179 ROME,ITALY.
C3 Sapienza University Rome; Sapienza University Rome
NR 19
TC 173
Z9 183
U1 0
U2 13
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 235
EP 237
DI 10.1038/364235a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300056
PM 8321319
DA 2026-03-10
ER

PT J
AU FERGUSON, EM
   KLEIN, EM
AF FERGUSON, EM
   KLEIN, EM
TI FRESH BASALTS FROM THE PACIFIC ANTARCTIC RIDGE EXTEND THE PACIFIC GEOCHEMICAL PROVINCE
SO NATURE
LA English
DT Article
ID southeast indian ridge; isotope geochemistry; fuca ridge; ocean; mantle; petrogenesis; discordance; chemistry; boundary; systems
AB OVER the past several decades, the examination of volcanic rocks recovered from mid-ocean ridges and ocean islands worldwide has led to the identification of large-scale geochemical provinces reflecting compositionally distinct domains in the Earth's mantle1,2. The spatial distribution of these domains may reveal global patterns of upper-mantle convection and mixing. Previous studies have shown, for example, that the distinct Indian Ocean isotope province1 has a relatively sharp eastern boundary within the Australian-Antarctic Discordance (AAD) south of Australia3,4 (Fig. 1). The juxtaposition of Indian Ocean basalt compositions west of this boundary and Pacific compositions to the east suggests that the AAD may overlie a zone of convergence between ocean-basin-scale upper-mantle convection regimes: if this is so, Pacific isotope compositions should occur continuously along the length of the Pacific-Antarctic Ridge (PAR). Fresh basaltic glasses have now been recovered from the southernmost portion of this previously unsampled ridge axis, and we report their major element, trace element and isotopic compositions. The chemical systematics of these rocks suggest that the Pacific Ocean geochemical province includes the PAR, extends to the AAD south of Australia, and thus is one of the largest chemically coherent mantle domains on the Earth.
RP FERGUSON, EM (corresponding author), DUKE UNIV,DEPT GEOL,DURHAM,NC 27708, USA.
NR 28
TC 28
Z9 30
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 330
EP 333
DI 10.1038/366330a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500044
DA 2026-03-10
ER

PT J
AU MERINO, A
   MADDEN, KR
   LANE, WS
   CHAMPOUX, JJ
   REINBERG, D
AF MERINO, A
   MADDEN, KR
   LANE, WS
   CHAMPOUX, JJ
   REINBERG, D
TI DNA TOPOISOMERASE-I IS INVOLVED IN BOTH REPRESSION AND ACTIVATION OF TRANSCRIPTION
SO NATURE
LA English
DT Article
ID rna polymerase-ii; binding; cloning; protein; yeast; gene; complex; purification; coactivators; initiation
AB Reconstituted transcription reactions containing the seven general transcription factors, in addition to RNA polymerase II, respond poorly to transcriptional activators. Two factors, Dr2 and ACF, necessary for high levels of transcription in response to an activator have been identified. ACF can enhance basal and activated transcription. Dr2 represses basal transcription, but this can be overcome by transcriptional activators or TFIIA. Dr2 is human DNA topoisomerase I. The DNA relaxation activity of topoisomerase I is dispensable for transcriptional repreSSion. The effect of Dr2 is specific for TATA-box-containing promoters and is mediated by the TATA-binding protein.
C1 UNIV MED & DENT NEW JERSEY,ROBERT WOOD JOHNSON MED SCH,DEPT BIOCHEM,PISCATAWAY,NJ 08854.
   UNIV WASHINGTON,DEPT MICROBIOL,SEATTLE,WA 98195.
   HARVARD MICROCHEM FACIL,CAMBRIDGE,MA 02138.
C3 Rutgers University System; Rutgers University New Brunswick; Rutgers University Biomedical & Health Sciences; University of Washington; University of Washington Seattle; Harvard University
NR 47
TC 352
Z9 382
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 227
EP 232
DI 10.1038/365227a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100045
PM 8396729
DA 2026-03-10
ER

PT J
AU LUCAS, SB
   GREEN, A
   HAJNAL, Z
   WHITE, D
   LEWRY, J
   ASHTON, K
   WEBER, W
   CLOWES, R
AF LUCAS, SB
   GREEN, A
   HAJNAL, Z
   WHITE, D
   LEWRY, J
   ASHTON, K
   WEBER, W
   CLOWES, R
TI DEEP SEISMIC PROFILE ACROSS A PROTEROZOIC COLLISION ZONE - SURPRISES AT DEPTH
SO NATURE
LA English
DT Article
ID western churchill province; united-states; reflection; tectonics; terranes; canada; crust; ga
AB COLLISIONS between continents generate the world's most striking mountains; the deep structure of these collision zones, inferred from seismic reflection profiles1-3, can be equally dramatic, if less well understood. Improved knowledge of the structure of ancient collisional belts, now known to have developed through plate tectonic processes4,5, can provide important new insights into the mechanisms of crustal growth. Although many such belts have been partly destroyed by severe post-collisional deformation6,7 or magmatism8, some have been preserved in the stable interiors of continents9: one example is the Early Proterozoic Trans-Hudson orogen9,10, in western Canada. Here we present seismic reflection images across the entire orogen, which reveal a broadly symmetric structure, with reflections linked to island-arc rocks dipping beneath both bounding Archaean cratons. The observed reflection geometries imply a doubling of crustal thickness during the collision, along crust-penetrating faults. The presence of a significant amount of Archaean crust at depth, the extent of which could not have been determined from surface mapping, suggests the need for caution in inferring crustal growth rate from the surface area of juvenile crust11,12.
C1 SWISS FED INST TECHNOL,INST GEOPHYS,CH-8093 ZURICH,SWITZERLAND.
   UNIV SASKATCHEWAN,DEPT GEOL SCI,SASKATOON S7N 0W0,SASKATCHEWAN,CANADA.
   UNIV REGINA,DEPT GEOL,REGINA S4S 0A2,SASKATCHEWAN,CANADA.
   SASKATCHEWAN GEOL SURVEY,REGINA S4P 4V4,SK,CANADA.
   MANITOBA GEOL SURVEYS BRANCH,WINNIPEG R3C 4E3,MB,CANADA.
   UNIV BRITISH COLUMBIA,LITHOPROBE,VANCOUVER V6T 1Z4,BC,CANADA.
C3 Swiss Federal Institutes of Technology Domain; ETH Zurich; University of Saskatchewan; University of Regina; University of British Columbia
RP LUCAS, SB (corresponding author), GEOL SURVEY CANADA,601 BOOTH ST,OTTAWA K1A 0E8,ONTARIO,CANADA.
NR 30
TC 153
Z9 160
U1 1
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 339
EP 342
DI 10.1038/363339a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700049
DA 2026-03-10
ER

PT J
AU KEPPLER, H
   RUBIE, DC
AF KEPPLER, H
   RUBIE, DC
TI PRESSURE-INDUCED COORDINATION CHANGES OF TRANSITION-METAL IONS IN SILICATE MELTS
SO NATURE
LA English
DT Article
ID chemical-model; early history; earth; olivine; moon; constraints; liquid; nickel; origin
AB THE strong partitioning of cobalt and nickel from silicate melts into solid silicate and metal phases1-3 during the large-scale fractionation processes that took place early in Earth history4-9 determines their abundance in mantle-derived magmas and in the metallic core. The global distributions of these elements have therefore been used to constrain models of the Earth's chemical evolution4-8, as well as that of the Moon10,11. But in virtually all model calculations4,6,7,10,11 the effect of pressure on partitioning has been neglected - these models have used partition coefficients determined at very low pressures. Here we present crystal-field spectra of doped silicate glasses quenched from high-pressure, high-temperature melts, which show that the coordination of cobalt and nickel ions in silicate melts changes at high pressures. Our results suggest that the partitioning of these species into the melt phase increases markedly with pressure, such that the crystal/melt and metal/melt partition coefficients decrease by more than an order of magnitude at lower-mantle conditions.
RP KEPPLER, H (corresponding author), UNIV BAYREUTH,BAYER GEOINST,W-8580 BAYREUTH,GERMANY.
NR 20
TC 57
Z9 58
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 54
EP 56
DI 10.1038/364054a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800054
DA 2026-03-10
ER

PT J
AU BERG, EL
   MCEVOY, LM
   BERLIN, C
   BARGATZE, RF
   BUTCHER, EC
AF BERG, EL
   MCEVOY, LM
   BERLIN, C
   BARGATZE, RF
   BUTCHER, EC
TI L-SELECTIN-MEDIATED LYMPHOCYTE ROLLING ON MADCAM-1
SO NATURE
LA English
DT Article
ID endothelial cell recognition; node homing receptor; vascular addressin; ligand; molecule; identification; migration; adhesion; venules; specificity
AB THE L-selectin, a cell surface C-type lectin, directs lymphocyte traffic to lymph nodes1, and contributes to lymphocyte homing to Peyer's patches2,3 and to leukocyte interactions with inflamed venules4,5. Here we report that the mucosal vascular addressin MAdCAM-1, a mucosal endothelial adhesion molecule with immunoglobulin- and mucin-like domains6, is a facultative ligand for L-selectin. MAdCAM-1 isolated from mesenteric lymph nodes, but not from cultured endothelioma cells, bears N-glycanase-resistant sialic acid-containing carbohydrate which supports adhesion of L-selectin-transfected lymphoid cells under shear. Interacting lymphoid cells display a 'rolling' behaviour similar to the selectin-dependent rolling of neutrophils observed in inflamed venules. MAdCAM-1 is also a ligand for the lymphocyte integrin homing receptor for Peyer's patches, alpha4beta7 (ref. 7), and may be uniquely adapted to support both selectin-mediated lymphocyte rolling and integrin-mediated adhesion and arrest in vivo.
C1 STANFORD UNIV,DEPT PATHOL,IMMUNOL & VASC BIOL LAB,STANFORD,CA 94305.
   VET ADM MED CTR,FOOTHILL RES CTR,CTR MOLEC BIOL & MED,PALO ALTO,CA 94304.
C3 Stanford University; US Department of Veterans Affairs; Veterans Health Administration (VHA)
NR 30
TC 500
Z9 546
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 695
EP 698
DI 10.1038/366695a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500072
PM 7505053
DA 2026-03-10
ER

PT J
AU AZUMA, M
   ITO, D
   YAGITA, H
   OKUMURA, K
   PHILLIPS, JH
   LANIER, LL
   SOMOZA, C
AF AZUMA, M
   ITO, D
   YAGITA, H
   OKUMURA, K
   PHILLIPS, JH
   LANIER, LL
   SOMOZA, C
TI B70 ANTIGEN IS A 2ND LIGAND FOR CTLA-4 AND CD28
SO NATURE
LA English
DT Article
ID t-cell activation; costimulatory signal; lymphocytes-t; b-cells; expression; amplification; superfamily; mechanism; receptor; b7/bb-1
AB THE membrane antigen B7/BB1 (refs 1, 2) is expressed on activated B cells, macrophages and dendritic cells, and binds to a counter-receptor, CD28, expressed on T lymphocytes and thymocytes3. Interaction between CD28 and B7 results in potent costimulation of T-cell activation initiated through the CD3/T-cell receptor complex4,5. Discrepancies between results with anti-CD28 and anti-B7 antibodies have suggested the existence of a second ligand for CD28 and CTLA-4 (refs 3, 6-8). We have generated a monoclonal antibody, IT2, that reacts with a 70K glycoprotein (B70). B70 complementary DNA was cloned from a B-lymphoblastoid cell line library and encodes a new protein of the immunoglobulin superfamily with limited homology to B7. B70 is expressed on resting monocytes and dendritic cells and on activated, but not resting, T, NK and B lymphocytes. IT2 substantially inhibited the binding of a CTLA4-immunoglobulin fusion protein to human B-lymphoblastoid cell lines and, together with anti-B7 antibody, completely blocked CTLA-4 binding. Further IT2 efficiently inhibited primary allogeneic mixed lymphocyte responses. These findings indicate that B70 is a second ligand for CD28 and CTLA-4 and may play an important role for costimulation of T cells in a primary immune response.
C1 UNIV TOKYO,FAC MED,DEPT ORAL & MAXILLOFACIAL SURG,BUNKYO KU,TOKYO 113,JAPAN.
   DNAX RES INST MOLEC & CELLULAR BIOL INC,DEPT IMMUNOL,PALO ALTO,CA 94304.
C3 University of Tokyo; Merck & Company; Dnax Research Institute Of Molecular & Cellular Biology Inc.
RP AZUMA, M (corresponding author), JUNTENDO UNIV,SCH MED,DEPT IMMUNOL,HONGO 2-1-1,BUNKYO KU,TOKYO 113,JAPAN.
NR 24
TC 949
Z9 1107
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 76
EP 79
DI 10.1038/366076a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700058
PM 7694153
DA 2026-03-10
ER

PT J
AU JONIDES, J
   SMITH, EE
   KOEPPE, RA
   AWH, E
   MINOSHIMA, S
   MINTUN, MA
AF JONIDES, J
   SMITH, EE
   KOEPPE, RA
   AWH, E
   MINOSHIMA, S
   MINTUN, MA
TI SPATIAL WORKING-MEMORY IN HUMANS AS REVEALED BY PET
SO NATURE
LA English
DT Article
ID prefrontal cortex; imagery
AB THE concept of working memory is central to theories of human cognition because working memory is essential to such human skills as language comprehension and deductive reasoning1-4. Working memory is thought to be composed of two parts, a set of buffers that temporarily store information in either a phonological or visuospatial form, and a central executive responsible for various computations such as mental arithmetic5,6. Although most data on working memory come from behavioural studies of normal and brain-injured humans7, there is evidence about its physiological basis from invasive studies of monkeys8-10. Here we report positron emission tomography (PET) studies of regional cerebral blood flow in normal humans that reveal activation in right-hemisphere prefrontal, occipital, parietal and premotor cortices accompanying spatial working memory processes. These results begin to uncover the circuitry of a working memory system in humans.
C1 UNIV MICHIGAN, DEPT INTERNAL MED, ANN ARBOR, MI 48109 USA.
   PRESBYTERIAN UNIV HOSP, DIV NUCL MED, PITTSBURGH, PA 15213 USA.
C3 University of Michigan System; University of Michigan; Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh; UPMC Presbyterian
RP JONIDES, J (corresponding author), UNIV MICHIGAN, DEPT PSYCHOL, ANN ARBOR, MI 48109 USA.
NR 21
TC 944
Z9 1061
U1 1
U2 65
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 623
EP 625
DI 10.1038/363623a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900054
PM 8510752
DA 2026-03-10
ER

PT J
AU ROBERTS, N
   TAIEB, M
   BARKER, P
   DAMNATI, B
   ICOLE, M
   WILLIAMSON, D
AF ROBERTS, N
   TAIEB, M
   BARKER, P
   DAMNATI, B
   ICOLE, M
   WILLIAMSON, D
TI TIMING OF THE YOUNGER DRYAS EVENT IN EAST-AFRICA FROM LAKE-LEVEL CHANGES
SO NATURE
LA English
DT Article
ID magadi kenya; circulation; pleistocene; deposits; climate; record
AB THE last deglaciation was interrupted by an abrupt cooling event, the Younger Dryas, at 11,000-10,000 yr BP (uncalibrated radiocarbon timescale)1. Originally recognized in climate records from northwest Europe, the Younger Dryas has now been identified in marine and ice-core records worldwide2-6. In the tropics, a broadly contemporaneous change in climate is recorded by decreases in water levels and increased salinity of lakes7-9,14, indicating a period of arid climate caused by a reduction in ocean-to-land moisture flux. The exact timing of these changes in relation to the Younger Dryas event in high-latitude records has remained unclear, however. Here we present climate records based on analyses of diatom assemblages, geochemistry and magnetic mineralogy of radio-carbon-dated sequences of laminated lake sediments from Lake Magadi in the East African rift. These records provide a detailed record of climate change in lowland equatorial Africa throughout the last deglaciation (12,800-10,000 C-14 yr BP). We find that lake-level and humidity maxima coincide with the most rapid phases of ice melting in the Northern Hemisphere, and that the climate changes, including the Younger Dryas event, were synchronous at low and high latitudes. Thus, the effects of abrupt climate change appear to be felt at both high and low latitudes without a significant time lag.
C1 CNRS,GEOL QUATERNAIRE LAB,F-13288 MARSEILLE 9,FRANCE.
C3 Centre National de la Recherche Scientifique (CNRS)
RP ROBERTS, N (corresponding author), LOUGHBOROUGH UNIV TECHNOL,DEPT GEOG,LOUGHBOROUGH LE11 3TU,LEICS,ENGLAND.
NR 27
TC 133
Z9 145
U1 1
U2 64
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 146
EP 148
DI 10.1038/366146a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600053
DA 2026-03-10
ER

PT J
AU SPARKS, RS
   HUPPERT, HE
   KOYAGUCHI, T
   HALLWORTH, MA
AF SPARKS, RS
   HUPPERT, HE
   KOYAGUCHI, T
   HALLWORTH, MA
TI ORIGIN OF MODAL AND RHYTHMIC IGNEOUS LAYERING BY SEDIMENTATION IN A CONVECTING MAGMA CHAMBER
SO NATURE
LA English
DT Article
ID fluid; crystallization; differentiation
AB EXPERIMENTAL investigations of convecting, particle-laden fluids show two regimes for convection driven by cooling from above1. In very dilute suspensions, convection will maintain a homogeneous distribution of particles throughout the convecting layer provided that particle fall velocities are small compared with turbulent fluid velocities. Above a critical concentration, convection is unable to keep the particles suspended, so the particles settle, leaving behind a layer of convecting fluid virtually free of particles. Here we apply these results to cooling magma chambers, in which crystallization leads to an increase in suspended crystal content with time. Discrete sedimentation events are predicted each time the concentration exceeds the critical value. For common igneous minerals, critical concentrations are very small (typically 0.002-0.03 wt %) and layers of the order of centimetres to a few metres thick will result. Because minerals of different density and size have different critical concentrations and settling velocities, complex fluctuations in sedimentation rate and mineral proportions can occur in a multi-component melt. This may lead to either regular repetitive cycles or more complex fluctuations. The process is confined to low-viscosity magmas, such as basalts, in which the crystals are able to separate from the active thermal boundary layer during convection.
C1 UNIV CAMBRIDGE,INST THEORET GEOPHYS,CAMBRIDGE CB3 9EW,ENGLAND.
   UNIV TOKYO,EARTHQUAKE RES INST,TOKYO 113,JAPAN.
C3 University of Cambridge; University of Tokyo
RP SPARKS, RS (corresponding author), UNIV BRISTOL,DEPT GEOL,BRISTOL BS8 1RJ,ENGLAND.
NR 23
TC 61
Z9 69
U1 0
U2 17
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 246
EP 249
DI 10.1038/361246a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400054
DA 2026-03-10
ER

PT J
AU MULLER, M
   BRISCOE, J
   LAXTON, C
   GUSCHIN, D
   ZIEMIECKI, A
   SILVENNOINEN, O
   HARPUR, AG
   BARBIERI, G
   WITTHUHN, BA
   SCHINDLER, C
   PELLEGRINI, S
   WILKS, AF
   IHLE, JN
   STARK, GR
   KERR, IM
AF MULLER, M
   BRISCOE, J
   LAXTON, C
   GUSCHIN, D
   ZIEMIECKI, A
   SILVENNOINEN, O
   HARPUR, AG
   BARBIERI, G
   WITTHUHN, BA
   SCHINDLER, C
   PELLEGRINI, S
   WILKS, AF
   IHLE, JN
   STARK, GR
   KERR, IM
TI THE PROTEIN-TYROSINE KINASE JAK1 COMPLEMENTS DEFECTS IN INTERFERON-ALPHA/BETA AND INTERFERON-GAMMA SIGNAL-TRANSDUCTION
SO NATURE
LA English
DT Article
ID dna-binding protein; transcription factor; stimulated transcription; cytoplasmic activation; ifn-gamma; receptor; phosphorylation; cloning; cells; cdna
AB We have produced a cell line which lacks the protein tyrosine kinase JAK1. and is completely, defective in interferon response. Complementation of this mutant with JAK1 restored the response, establishing the requirement for JAK1 in both the interferon-alpha/beta and -gamma signal transduction pathways. The reciprocal interdependence between JAK1 and Tyk2 activities in the interferon-alpha pathway, and between JAK1 and JAK2 in the interferon-gamma pathway, may reflect a requirement for these kinases in the correct assembly of interferon receptor complexes.
C1 IMPERIAL CANC RES FUND, POB 124, 44 LINCOLNS FIELDS, LONDON WC2A 3PX, ENGLAND.
   UNIV BERN, INST CLIN & EXPTL CANC RES, CH-3004 BERN, SWITZERLAND.
   NYU MED CTR, NEW YORK, NY 10016 USA.
   LUDWIG INST CANC RES, MELBOURNE TUMOUR BIOL BRANCH, MELBOURNE, VIC 3050, AUSTRALIA.
   INST PASTEUR, INSERM, U276, F-75724 PARIS 15, FRANCE.
   ST JUDE CHILDRENS RES HOSP, MEMPHIS, TN 38101 USA.
   COLUMBIA UNIV, MED CTR, DEPT MED, NEW YORK, NY 10032 USA.
   CLEVELAND CLIN FDN, RES INST, CLEVELAND, OH 44195 USA.
C3 Cancer Research UK; University of Bern; New York University; Ludwig Institute for Cancer Research; Pasteur Network; Universite Paris Cite; Institut Pasteur Paris; Institut National de la Sante et de la Recherche Medicale (Inserm); St Jude Children's Research Hospital; Columbia University; Cleveland Clinic Foundation
NR 51
TC 749
Z9 817
U1 0
U2 25
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 129
EP 135
DI 10.1038/366129a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600048
PM 8232552
DA 2026-03-10
ER

PT J
AU GALE, NW
   KAPLAN, S
   LOWENSTEIN, EJ
   SCHLESSINGER, J
   BARSAGI, D
AF GALE, NW
   KAPLAN, S
   LOWENSTEIN, EJ
   SCHLESSINGER, J
   BARSAGI, D
TI GRB2 MEDIATES THE EGF-DEPENDENT ACTIVATION OF GUANINE-NUCLEOTIDE EXCHANGE ON RAS
SO NATURE
LA English
DT Article
ID tyrosine kinase-activity; growth-factor; insulin; p21ras; gene; stimulation; mutation; products; family; cells
AB ACTIVATION of receptor tyrosine kinases such as those for epidermal growth factor (EGF), platelet-derived growth factor, or nerve growth factor converts the inactive, GDP-bound form of Ras to the active, GTP-bound form1-4, and a dominant negative mutant of Ras interferes with signalling from such receptors5-8. The mechanisms by which receptor tyrosine kinases and Ras are coupled, however, are not well understood. Many cytoplasmic proteins regulated by such receptors contain Src-homology (SH) 2 and 3 domains, and the SH2- and SH3-containing protein Grb2, like its homologue from Caenorhabditis elegans, Sem-5, appears to play an important role in the control of Ras by receptor tyrosine kinases9-11. Here we show that overexpression of Grb2 potentiates the EGF-induced activation of Ras and mitogen-activated protein kinase by enhancing the rate of guanine nucleotide exchange on Ras. Cellular Grb2 appears to form a complex with a guanine-nucleotide-exchange factor for Ras, which binds to the ligand-activated EGF receptor, allowing the tyrosine kinase to modulate Ras activity.
C1 COLD SPRING HARBOR LAB,1 BUNGTOWN RD,BOX 100,COLD SPRING HARBOR,NY 11724.
   NYU MED CTR,DEPT PHARMACOL,NEW YORK,NY 10016.
C3 Cold Spring Harbor Laboratory; New York University
NR 30
TC 574
Z9 643
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 88
EP 92
DI 10.1038/363088a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200067
PM 8386805
DA 2026-03-10
ER

PT J
AU LOZANO, F
   RADA, C
   JARVIS, JM
   MILSTEIN, C
AF LOZANO, F
   RADA, C
   JARVIS, JM
   MILSTEIN, C
TI AFFINITY MATURATION LEADS TO DIFFERENTIAL EXPRESSION OF MULTIPLE COPIES OF A KAPPA-LIGHT-CHAIN TRANSGENE
SO NATURE
LA English
DT Article
ID somatic hypermutation; immunoglobulin-kappa; mutation
AB TRANSGENIC animals containing rearranged heavy or light chains are used to study the process of hypermutation, which characterizes the maturation of the antibody response1-3. LK6 mice contain five copies of a transgene coding for a light chain produced in response to the hapten 2-phenyloxazolone4. We have selected hybridomas from secondary responses that express the transgene as the only light chain2. Some of these hybridomas contain transgene copies carrying mutations known to improve antibody affinity5. We have analysed the expression of the five transgene copies in those hybridomas. We report here that the somatic hypermutation process can affect the successful expression of antibody light-chain transgenes. When mutations that improve the antibody affinity appear in one transgene copy, antigenic selection favours cells that downregulate the other copies at multiple levels of gene expression, including examples where nonsense mutations correlate with a drop in messenger RNA level.
RP LOZANO, F (corresponding author), MRC,MOLEC BIOL LAB,HILLS RD,CAMBRIDGE CB2 2QH,ENGLAND.
NR 20
TC 43
Z9 43
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 271
EP 273
DI 10.1038/363271a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600055
PM 8487865
DA 2026-03-10
ER

PT J
AU BELL, JF
   BAILES, M
   BESSELL, MS
AF BELL, JF
   BAILES, M
   BESSELL, MS
TI OPTICAL-DETECTION OF THE COMPANION OF THE MILLISECOND PULSAR-J0437 - 4715
SO NATURE
LA English
DT Article
ID binary pulsar; stars; radio; photometry; evolution; nebula; dwarf; identification
AB OPTICAL observations of the companion stars in binary pulsar Systems1-3 offer a way to estimate pulsar ages independent of calculations based on timing measurements of the radio pulses, and can therefore provide important constraints for models of pulsar evolution. Here we report the optical detection of the companion star of the nearby binary millisecond pulsar J0437 - 4715. The companion seems to be a very cool, quiescent white dwarf. The temperature inferred from the observations is less than that obtained from a cooling model of a white dwarf of an age equivalent to the 'spin-down' age of the pulsar. These observations provide direct support for the hypothesis1 that millisecond pulsars are long-lived objects, and that their magnetic fields do not decay.
C1 CSIRO,AUSTRALIA TELESCOPE NATL FACIL,EPPING,NSW 2121,AUSTRALIA.
C3 Commonwealth Scientific & Industrial Research Organisation (CSIRO); Australia Telescope National Facility
RP BELL, JF (corresponding author), MT STROMLO & SIDING SPRING OBSERV,WESTON,ACT 2611,AUSTRALIA.
NR 28
TC 73
Z9 75
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 603
EP 605
DI 10.1038/364603a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100044
DA 2026-03-10
ER

PT J
AU LAMME, VAF
   VANDIJK, BW
   SPEKREIJSE, H
AF LAMME, VAF
   VANDIJK, BW
   SPEKREIJSE, H
TI CONTOUR FROM MOTION PROCESSING OCCURS IN PRIMARY VISUAL-CORTEX
SO NATURE
LA English
DT Article
ID evoked-potentials; striate cortex; cat; cells; connections; orientation; selectivity; mechanisms; neurons
AB RELATIVE motion is one of the most salient cues for segmentation of a visual scene into separate objects. This is illustrated by the vivid contours that are perceived when random dot patterns move in different directions1,2. Once motion is hatted in such displays the segmentation contours disappear. This makes random dot patterns ideal for the study of contour from motion processing in isolation. Contour from motion processing obviously relies on direction-selective neurons, which are found in many visual cortical areas3-5. It is, however, largely unknown at what level of processing their signals interact to serve the global process of motion-based image segmentation. To answer this quesion, we recorded visually evoked potentials, both in man and in awake monkey, to a stimulus specifically designed to signal the presence of neuronal activity related to contour from motion processing. We report here that response components specific to contour from motion were elicited only when the stimulus yielded a contour percept. In awake monkey, the sources of these components were located within the supra- and infra-granular layers of primary visual cortex. We conclude that V1 is involved in image segmentation processing.
C1 NETHERLANDS OPHTHALM RES INST,POB 12141,1100 AC AMSTERDAM,NETHERLANDS.
   UNIV AMSTERDAM,MED PHYS LAB,1105 AZ AMSTERDAM,NETHERLANDS.
C3 Royal Netherlands Academy of Arts & Sciences; Netherlands Institute for Neuroscience (NIN-KNAW); University of Amsterdam
NR 19
TC 76
Z9 82
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 541
EP 543
DI 10.1038/363541a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900049
PM 8505980
DA 2026-03-10
ER

PT J
AU KOLCH, W
   HEIDECKER, G
   KOCHS, G
   HUMMEL, R
   VAHIDI, H
   MISCHAK, H
   FINKENZELLER, G
   MARME, D
   RAPP, UR
AF KOLCH, W
   HEIDECKER, G
   KOCHS, G
   HUMMEL, R
   VAHIDI, H
   MISCHAK, H
   FINKENZELLER, G
   MARME, D
   RAPP, UR
TI PROTEIN KINASE-C-ALPHA ACTIVATES RAF-1 BY DIRECT PHOSPHORYLATION
SO NATURE
LA English
DT Article
AB THE kinase Raf-1 can be activated by treatment of cells with mitogens and by the protein kinase C (PKC) activator 12-O-tetradecanoyl-phorbol-13-acetate (TPA) (reviewed in refs 1,2). Activated Raf-1 triggers a protein kinase cascade by direct phosphorylation of MAP kinase kinase3-5, resulting in phosphorylation of ternary complex factor6 and Jun7,8 by MAP kinase. Here we investigate the molecular mechanism and biological consequences of PKCalpha-mediated Raf-1 activation in NIH3T3 fibroblasts. PKCalpha directly phosphorylates and activates Raf-1 both in vitro and in vivo. PKCalpha induces Raf-1 phosphorylation at several sites, including a serine residue at position 499. Mutation of serine at this position or at residue 259 does not abrogate Raf-1 stimulation by a combination of Ras plus the src tyrosine kinase Lck, but severely impedes Raf-1 activation by PKCalpha. Consistent with such a direct interaction is the observation that Raf-1 and PKCalpha cooperate in the transformation of NIH3T3 cells. The Ser499 phosphorylation site is necessary for this synergism.
C1 GODECKE AG,BIOL RES,W-7800 FREIBURG,GERMANY.
   NCI,FCRDC,VIRAL CARCINOGENESIS LAB,FREDERICK,MD 21702.
   UNIV FREIBURG,GOEDECKE AG,INST MOLEC CELL BIOL,W-7800 FREIBURG,GERMANY.
   NCI,GENET LAB,BETHESDA,MD 20892.
C3 National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI); University of Freiburg; National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI)
NR 19
TC 1258
Z9 1362
U1 0
U2 32
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 249
EP 252
DI 10.1038/364249a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300061
PM 8321321
DA 2026-03-10
ER

PT J
AU CHOW, LML
   FOURNEL, M
   DAVIDSON, D
   VEILLETTE, A
AF CHOW, LML
   FOURNEL, M
   DAVIDSON, D
   VEILLETTE, A
TI NEGATIVE REGULATION OF T-CELL RECEPTOR SIGNALING BY TYROSINE PROTEIN-KINASE P50(CSK)
SO NATURE
LA English
DT Article
ID antigen receptor; c-src; responsiveness; activation; gene; phosphorylation; enhancement; expression; retrovirus; cloning
AB TYROSINE protein phosphorylation is necessary for antigen receptor-mediated activation of T lymphocytes1. This signal is generated at least in part by the Src-related tyrosine protein kinases p56lck and p59fynT (refs 2, 3). The activity of these two enzymes is repressed by phosphorylation of a conserved carboxy-terminal tyrosine residue2,3. Recent studies suggest that this inhibitory phosphorylation may be caused by p50csk (for C-terminal Src kinase), a tyrosine protein kinase which accumulates most abundantly in thymus and spleen4-8. To investigate the function of Csk in T lymphocytes and characterize the processes regulating T-cell receptor (TCR) signalling, we examined the effects of overexpression of Csk on the physiology of an antigen-specific mouse T-cell line. We report here that p50csk negatively regulates TCR-induced tyrosine protein phosphorylation and lymphokine production. This provides evidence for the involvement of Csk in the regulation of T-cell activation.
C1 MCGILL UNIV,DEPT BIOCHEM,ROOM 715B,MCINTYRE MED SCI BLDG,3655 DRUMMOND ST,MONTREAL H3G 1Y6,QUEBEC,CANADA.
   MONTREAL GEN HOSP,DEPT MED,DIV MED ONCOL,MONTREAL H3G 1A4,QUEBEC,CANADA.
   MCGILL UNIV,MCGILL CANC CTR,MONTREAL H3G 1Y6,QUEBEC,CANADA.
   MCGILL UNIV,DEPT MED,MONTREAL H3G 1Y6,QUEBEC,CANADA.
   MCGILL UNIV,DEPT ONCOL,MONTREAL H3G 1Y6,QUEBEC,CANADA.
C3 McGill University; McGill University; McGill University; McGill University; McGill University
NR 27
TC 256
Z9 288
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 156
EP 160
DI 10.1038/365156a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200047
PM 8371758
DA 2026-03-10
ER

PT J
AU RUPPERT, S
   WANG, EH
   TJIAN, R
AF RUPPERT, S
   WANG, EH
   TJIAN, R
TI CLONING AND EXPRESSION OF HUMAN TAF(II)250 - A TBP-ASSOCIATED FACTOR IMPLICATED IN CELL-CYCLE REGULATION
SO NATURE
LA English
DT Article
ID binding-protein; tfiid complex; mutants; transcription; coactivators; progression; activation; system; genes; ccg1
AB BASAL transcription by human RNA polymerase II requires the coordinate action of several ancillary factors (TFIIA-J)1 and can be regulated by various promoter-specific DNA binding proteins. An additional class of factors, called coactivators, are dispensable for basal transcription but are indispensable for regulation by transcriptional activators2-4. Biochemical studies established that some coactivators are associated with the TATA-binding protein (TBP) to form the TFIID complex3-6. We therefore set out to define the relationship between TBP and these TBP-associated factors (TAFs). Here we describe the cloning, expression and properties of the first human TAF, hTAF(II)250. The hTAF(II)250 gene is identical to a gene, CCG1 (refs 7, 8), implicated in cell-cycle progression. Recombinant hTAF(II)250 binds directly to TBP both in vitro and in yeast, and participates in the formation of the TFIID complex. This largest TAF may therefore play a central role in TFIID assembly by interacting with both TBP and other TAFs, as well as serving to link the control of transcription to the cell cycle.
RP RUPPERT, S (corresponding author), UNIV CALIF BERKELEY,DEPT MOLEC & CELL BIOL,HOWARD HUGHES MED INST,401 BARKER HALL,BERKELEY,CA 94720, USA.
NR 22
TC 226
Z9 271
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 175
EP 179
DI 10.1038/362175a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800065
PM 7680771
DA 2026-03-10
ER

PT J
AU DAVIES, K
AF DAVIES, K
TI OF MICE AND MEN (AND COWS AND CATS)
SO NATURE
LA English
DT Article
NR 7
TC 7
Z9 7
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 478
EP 478
DI 10.1038/361478a0
PG 1
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300070
PM 8429890
DA 2026-03-10
ER

PT J
AU JAFFE, W
   FORD, HC
   FERRARESE, L
   VANDENBOSCH, F
   OCONNELL, RW
AF JAFFE, W
   FORD, HC
   FERRARESE, L
   VANDENBOSCH, F
   OCONNELL, RW
TI A LARGE NUCLEAR ACCRETION DISK IN THE ACTIVE GALAXY NGC4261
SO NATURE
LA English
DT Article
ID elliptical galaxy; virgo cluster
AB THE powerful emissions from the nuclei of active galaxies and quasars are thought to arise from the accretion of matter onto a massive black hole. Angular momentum will prevent matter from falling directly onto the central mass; instead, an 'accretion disk' should form, within which the gravitationally bound material will lose angular momentum and gradually spiral inwards. Accretion disks in active galactic nuclei have not hitherto been observed directly, but theoretical models1 suggest that they are comparable in size to the gravitational radius of the central black hole (about 10(13) cm) and are heated to high temperatures by the energy released from the accreting matter. Using the Planetary Camera on the Hubble Space Telescope, we have discovered an unexpectedly large (2 x 10(20) cm radius) disk of cool dust and gas surrounding a bright unresolved nucleus in the active galaxy NGC4261. We suggest that the bright point corresponds to thermal emission from the hot disk favoured by theoreticians, and that this is fuelled by material flowing from the cool 'outer' accretion disk. The spin axis of the accretion disk appears to determine the direction of the galaxy's radio jets.
C1 JOHNS HOPKINS UNIV,DEPT ASTRON & PHYS,BALTIMORE,MD 21218.
   SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218.
   UNIV VIRGINIA,DEPT ASTRON,CHARLOTTESVILLE,VA 22901.
C3 Johns Hopkins University; Space Telescope Science Institute; University of Virginia
RP JAFFE, W (corresponding author), LEIDEN OBSERV,PB 9513,2300 RA LEIDEN,NETHERLANDS.
NR 13
TC 136
Z9 144
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 213
EP 215
DI 10.1038/364213a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300048
DA 2026-03-10
ER

PT J
AU WHITE, N
AF WHITE, N
TI RECOVERY OF STRAIN-RATE VARIATION FROM INVERSION OF SUBSIDENCE DATA
SO NATURE
LA English
DT Article
ID north-sea basin; continental lithosphere; active deformation; extension; rocks; constraints; evolution; arc
AB DESPITE considerable advances over the past 20 years in our understanding of continental lithospheric deformation (see, for example, refs 1 and 2), we know little about the detailed spatial and temporal variations in strain rate at geologically relevant scales (approximately 10(2)-10(4) km and approximately 1-100 million years). Such measurements are needed to constrain dynamic models of lithospheric deformation3. Although it is not yet obvious how detailed strain-rate information can be obtained from mountain belts, subsidence data from sedimentary basins should contain information about at least the vertical component of the strain-rate tensor. Here I show that inverse theory can be used to calculate the temporal strain rate variation needed to fit observed subsidence patterns in extensional sedimentary basins. No a priori information concerning either the duration of rifting or the total strain is required. Inverse calculations produce good fits to synthetic data and to subsidence data from the Dolomites of northern Italy. Calculated strain rates are not constant but vary between 10(-18) and 10(-15) s-1.  Error analysis shows that these results are significant and well resolved. All of the stratigraphic sections studied exhibit a minimum in strain rate during extension-a feature predicted by models of lithosphere deformation by power-law creep.
RP WHITE, N (corresponding author), BULLARD LABS,MADINGLEY RISE,MADINGLEY RD,CAMBRIDGE CB3 0EZ,ENGLAND.
NR 19
TC 39
Z9 43
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 449
EP 452
DI 10.1038/366449a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800059
DA 2026-03-10
ER

PT J
AU SWINBANKS, D
AF SWINBANKS, D
TI WHAT ROAD AHEAD FOR KOREAN SCIENCE AND TECHNOLOGY
SO NATURE
LA English
DT Article
NR 1
TC 5
Z9 5
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 377
EP 384
DI 
PG 8
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000023
DA 2026-03-10
ER

PT J
AU DILL, M
   WOLF, R
   HEISENBERG, M
AF DILL, M
   WOLF, R
   HEISENBERG, M
TI VISUAL-PATTERN RECOGNITION IN DROSOPHILA INVOLVES RETINOTOPIC MATCHING
SO NATURE
LA English
DT Article
ID bees; discrimination; orientation
AB HONEYBEES remember the shapes of flowers and are guided by visual landmarks on their foraging trips1,2. How insects recognize visual patterns is poorly understood. Experiments suggest that they try to match retinotopically the incoming visual pattern with a previously stored memory image2-7. But bees can be conditioned to individual pattern parameters such as orientation of contours, colour or size2,8-11. These and other results are difficult to reconcile with simple template matching. In such investigations, freely moving animals are observed; their behaviour and visual input, therefore, are not well known. Mostly, processing strategies are inferred from stimulus design. We have studied visual pattern recognition with tethered flies (Drosophila melanogaster) in a flight simulator and report here that flies store visual images at, or together with, fixed retinal positions and can retrieve them from there only5. Position invariance, an acknowledged property of human pattern recognition, may no exist as a primary mechanism in insects.
C1 THEODOR BOVERI INST BIOWISSENSCH, BIOZENTRUM, LEHRSTUHL GENET, HUBLAND, D-97074 WURZBURG, GERMANY.
NR 22
TC 106
Z9 115
U1 0
U2 18
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 751
EP 753
DI 10.1038/365751a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200062
PM 8413652
DA 2026-03-10
ER

PT J
AU MORRIS, M
AF MORRIS, M
TI TELLING TAILS EXPLAIN THE DISCREPANCY IN SEXUAL PARTNER REPORTS
SO NATURE
LA English
DT Article
ID hiv transmission; life-styles
AB AN anomaly often noted in surveys of sexual behaviour is that the number of female sexual partners reported by men exceeds the number of male partners reported by women1-3. This discrepancy is sometimes interpreted as evidence that surveys produce unreliable data due to sex-linked response and sampling bias. We report here that among the 90% of respondents reporting fewer than 20 lifetime partners, however, the ratio of male to female reports drops from 3.2:1 to 1.2:1. The anomaly thus appears to be driven by the upper tail of the contact distribution, an example of the general principle of outlier influence in data analysis. The implication is that sexual behaviour surveys provide reliable data in the main, and that simple improvements can increase precision in the upper tail to make these data more useful for modelling the spread of AIDS and other sexually transmitted diseases.
C1 COLUMBIA UNIV,DEPT SOCIOL,NEW YORK,NY 10027.
C3 Columbia University
RP MORRIS, M (corresponding author), UNIV CAMBRIDGE,ISAAC NEWTON INST MATH SCI,20 CLARKSON RD,CAMBRIDGE CB3 0EH,ENGLAND.
NR 19
TC 112
Z9 121
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 437
EP 440
DI 10.1038/365437a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300055
PM 8413586
DA 2026-03-10
ER

PT J
AU WANG, H
   KUNKEL, DD
   MARTIN, TM
   SCHWARTZKROIN, PA
   TEMPEL, BL
AF WANG, H
   KUNKEL, DD
   MARTIN, TM
   SCHWARTZKROIN, PA
   TEMPEL, BL
TI HETEROMULTIMERIC K+ CHANNELS IN TERMINAL AND JUXTAPARANODAL REGIONS OF NEURONS
SO NATURE
LA English
DT Article
ID potassium-channel; sodium-channels; ion channels; fibers; shaker; brain
AB VOLTAGE-GATED potassium (K+) channels display a wide variety of conductances and gating properties in vivo1-3. This diversity can be attributed not only to the presence of many K+-channel gene products, but also to the possibility that different K+-channel subunits co-assemble to form heteromultimeric channels in vivo. When expressed in Xenopus oocytes or transfected cells, K+-channel polypeptides assemble to form tetramers4.  Certain combinations of Shaker-like subunits have been shown to co-assemble, forming heteromultimeric channels with distinct properties5-7. It is not known, however, whether K+-channel polypeptides form heteromultimeric channels in vivo. Here we describe the co-localization of two Shaker-like voltage-gated K+-channel proteins, mKv1.1 and mKv1.2, in the juxtaparanodal regions of nodes of Ranvier in myelinated axons, and in terminal fields of basket cells in mouse cerebellum. We also show that mKv1.1 and mKv1.2 can be co-immunoprecipitated with specific antibodies that recognize only one of them. These data indicate that the two polypeptides occur in subcellular regions where rapid membrane repolarization may be important and that they form heteromultimeric channels in vivo.
C1 VET AFFAIRS MED CTR,CTR GERIATR RES EDUC & CLIN 182-B,SEATTLE,WA 98108.
   UNIV WASHINGTON,SCH MED,DEPT MED & PHARMACOL SJ30,SEATTLE,WA 98195.
   UNIV WASHINGTON,SCH MED,DEPT NEUROL SURG & PHYSIOL BIOPHYS RI20,SEATTLE,WA 98195.
C3 Geriatric Research Education & Clinical Center; US Department of Veterans Affairs; Veterans Health Administration (VHA); University of Washington; University of Washington Seattle; University of Washington; University of Washington Seattle
NR 27
TC 555
Z9 603
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 75
EP 79
DI 10.1038/365075a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600058
PM 8361541
DA 2026-03-10
ER

PT J
AU MCLAUGHLIN, PJ
   GOOCH, JT
   MANNHERZ, HG
   WEEDS, AG
AF MCLAUGHLIN, PJ
   GOOCH, JT
   MANNHERZ, HG
   WEEDS, AG
TI STRUCTURE OF GELSOLIN SEGMENT-1-ACTIN COMPLEX AND THE MECHANISM OF FILAMENT SEVERING
SO NATURE
LA English
DT Article
ID actin-binding proteins; human annexin-v; f-actin; plasma gelsolin; sites; sequence; domains; acid; crystallization; identification
AB The structure of the segment 1 domain of gelsolin, a protein that fragments actin filaments in cells, is reported in complex with actin. Segment 1 binds monomer using an apolar patch rimmed by hydrogen bonds in a cleft between actin domains. On the actin filament model it binds tangentially, disrupting only those contacts between adjacent subunits in one helical strand. The segment 1 fold is general for all segments of the gelsolin family because the conserved residues form the core of the structure. It also provides a basis for understanding the origin of an amyloidosis caused by a gelsolin variant.
C1 UNIV MARBURG,INST CYTOBIOL & CYTOPATHOL,W-3550 MARBURG,GERMANY.
C3 Philipps University Marburg
RP MCLAUGHLIN, PJ (corresponding author), MRC,MOLEC BIOL LAB,CAMBRIDGE CB2 2QH,ENGLAND.
NR 46
TC 539
Z9 584
U1 0
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 685
EP 692
DI 10.1038/364685a0
PG 8
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700047
PM 8395021
DA 2026-03-10
ER

PT J
AU JOHNSTON, S
   LORIMER, DR
   HARRISON, PA
   BAILES, M
   LYNE, AG
   BELL, JF
   KASPI, VM
   MANCHESTER, RN
   DAMICO, N
   NICASTROL, L
   JIN, SZ
AF JOHNSTON, S
   LORIMER, DR
   HARRISON, PA
   BAILES, M
   LYNE, AG
   BELL, JF
   KASPI, VM
   MANCHESTER, RN
   DAMICO, N
   NICASTROL, L
   JIN, SZ
TI DISCOVERY OF A VERY BRIGHT, NEARBY BINARY MILLISECOND PULSAR
SO NATURE
LA English
DT Article
ID evolution; parallax; system
AB DURING a survey of the southern sky for millisecond pulsars, we have discovered ne with by far the greatest flux density of any known millisecond pulsar, often exceeding 1 Jy at 430 MHz. The dispersion measure (integrated electron density along the line of sight) is the smallest for any known pulsar. This object, PSR J0437-4715, may be the closest known pulsar, and is several times closer than any other known millisecond pulsar. Its rotation period is 5.75 ms, and it is in a 5.7-day circular orbit with a low-mass companion. The spin-down energy flux density is the third highest known, after the Crab and Vela pulsars. These properties make possible studies of the pulsar at radio wavelengths with unprecedented detail, and indicate that it should be possible to detect both the pulsar and its companion at optical and perhaps shorter wavelengths.
C1 UNIV MANCHESTER,NUFFIELD RADIO ASTRON LABS,MACCLESFIELD SK11 9DL,CHESHIRE,ENGLAND.
   AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,WODEN,ACT 2606,AUSTRALIA.
   PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544.
   UNIV PALERMO,IST FIS,I-90123 PALERMO,ITALY.
   CNR,IST RADIOASTRON,I-40126 BOLOGNA,ITALY.
   BEIJING UNIV,DEPT GEOPHYS,BEIJING 100871,PEOPLES R CHINA.
C3 University of Manchester; Australian National University; Princeton University; University of Palermo; Consiglio Nazionale delle Ricerche (CNR); Istituto Nazionale Astrofisica (INAF); Peking University
RP JOHNSTON, S (corresponding author), CSIRO,AUSTRALIA TELESCOPE NATL FACIL,POB 76,EPPING,NSW 2121,AUSTRALIA.
NR 28
TC 165
Z9 177
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 613
EP 615
DI 10.1038/361613a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600055
DA 2026-03-10
ER

PT J
AU ASARNOW, DM
   CADO, D
   RAULET, DH
AF ASARNOW, DM
   CADO, D
   RAULET, DH
TI SELECTION IS NOT REQUIRED TO PRODUCE INVARIANT T-CELL RECEPTOR GAMMA-GENE JUNCTIONAL SEQUENCES
SO NATURE
LA English
DT Article
ID delta-antigen receptors; diversity; identification; rearrangement; recognition; generation; epithelium; enhancer; segments; locus
AB RECOMBINATION of V-, D- and J-gene segments can generate an enormous diversity of T-cell antigen receptor (TCR) gene sequences1,2. Although many gammadelta T cells fully exploit this diversification process, those in the epidermal and vaginal epithelium do not3,4, predominantly expressing invariant gammadelta receptors in which the V-(D)-J junctional sequences in almost all the productive rearrangements are identical. The almost exclusive use of identical TCRs by cells in these sites is thought to reflect recognition of a stress-induced autologous antigen5-8. To explain the prevalence of the invariant junctional sequences, it has been proposed that thymic selection operates on a population of originally diverse progenitor cells, resulting in a homogeneous repertoire9,10. Alternatively the invariant sequences may result from biases in the recombination machinery in the fetal thymic progenitors of these cells8,11,12. We report here the use of mice into which mutated TCR gamma-gene rearrangement substrates have been introduced as transgenes to demonstrate directly that the canonical TCR Vgamma3-Jgamma1 and Vgamma4-Jgamma1 sequences occur at high frequency in the absence of the possibility of selection for the protein products.
C1 UNIV CALIF BERKELEY,DEPT MOLEC & CELL BIOL,DIV IMMUNOL,489 LSA,BERKELEY,CA 94720.
C3 University of California System; University of California Berkeley
NR 21
TC 98
Z9 103
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 158
EP 160
DI 10.1038/362158a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800060
PM 8383806
DA 2026-03-10
ER

PT J
AU FARMER, DM
   MCNEIL, CL
   JOHNSON, BD
AF FARMER, DM
   MCNEIL, CL
   JOHNSON, BD
TI EVIDENCE FOR THE IMPORTANCE OF BUBBLES IN INCREASING AIR SEA GAS FLUX
SO NATURE
LA English
DT Article
ID breaking wind-waves; exchange; oxygen; water
AB TWO models have been proposed to account for gas exchange between the atmosphere and the oceans: one involves direct transport of the gas through a surface boundary layer1; the other also includes a substantial enhancement of the gas flux due to bubbles formed by breaking wave2,3. In a long time-series of dissolved oxygen measurements, Wallace and Wirick4 observed sharply increased fluxes that seemed to be associated with wave activity. But the lack of vertical resolution meant that they could not rule out water advection and entrainment, rather than bubble-mediated air injection, as the cause of the increased flux. They were also unable to calculate transfer coefficients. Here we report simultaneous in situ observations from a vertical array of dissolved-gas sensors and a variety of other instruments during a single storm event. Our results confirm the importance of bubbles for the gas-transfer process. They also imply that existing transfer coefficients underestimate the transfer of weakly soluble gases during periods of bubble penetration.
C1 UNIV VICTORIA, VICTORIA V8W 2Y2, BC, CANADA.
   DALHOUSIE UNIV, HALIFAX B3H 4H2, NS, CANADA.
C3 University of Victoria; Dalhousie University
RP FARMER, DM (corresponding author), FISHERIES & OCEANS CANADA INST OCEAN SCI, 9860 W SAANICH RD, POB 6000, SIDNEY V8L 4B2, BC, CANADA.
NR 19
TC 144
Z9 162
U1 1
U2 26
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 620
EP 623
DI 10.1038/361620a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600058
DA 2026-03-10
ER

PT J
AU FISHELL, G
   MASON, CA
   HATTEN, ME
AF FISHELL, G
   MASON, CA
   HATTEN, ME
TI DISPERSION OF NEURAL PROGENITORS WITHIN THE GERMINAL ZONES OF THE FOREBRAIN
SO NATURE
LA English
DT Article
ID cerebral-cortex; cell lineage; migration; invitro
AB ONE of the early events in the establishment of regional diversity in brain is the subdivision of the forebrain into the cerebral cortex1-7 and underlying basal ganglia8. This subdivision is of special interest, owing to the striking difference in cellular patterning in these two regions. Whereas the dorsal aspect of the telencephalon gives rise to the laminar, cortical regions of brain, the basal aspect gives rise to nuclear, subcortical regions. To examine early events in the regionalization of the forebrain, we visualized cell movement within the ventricular zones of the dorsal and basal regions of the E15 murine telencephalon. Over an 8-24-hour observation period, labelled cells moved extensively in the plane of the cortical ventricular zone. Cell dispersion was restricted, however, at the border between the cortical ventricular zone and the lateral ganglionic eminence, the basal telencephalic ventricular zone. We suggest that this restriction of cell movements establishes a regional pattern of neurogenesis in the developing brain.
C1 COLUMBIA UNIV COLL PHYS & SURG,CTR NEUROBIOL & BEHAV,DEPT PATHOL,NEW YORK,NY 10032.
C3 Columbia University
NR 29
TC 246
Z9 263
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 636
EP 638
DI 10.1038/362636a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800049
PM 8464514
DA 2026-03-10
ER

PT J
AU WOYCHIK, RP
   WASSOM, JS
   KINGSBURY, D
AF WOYCHIK, RP
   WASSOM, JS
   KINGSBURY, D
TI TBASE - A COMPUTERIZED DATABASE FOR TRANSGENIC ANIMALS AND TARGETED MUTATIONS
SO NATURE
LA English
DT Article
C1 JOHNS HOPKINS UNIV,BALTIMORE,MD 21218.
C3 Johns Hopkins University
RP WOYCHIK, RP (corresponding author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA.
NR 5
TC 21
Z9 21
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 375
EP 376
DI 10.1038/363375a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700061
PM 8497324
DA 2026-03-10
ER

PT J
AU IWAMORI, H
AF IWAMORI, H
TI A MODEL FOR DISEQUILIBRIUM MANTLE MELTING INCORPORATING MELT TRANSPORT BY POROUS AND CHANNEL FLOWS
SO NATURE
LA English
DT Article
AB ATTEMPTS to understand melt transport in the Earth's mantle have focused on the two mechanisms of porous flow along grain boundaries1-4 and channel flow in fractures5-10. To elucidate the contributions of these segregation processes to the chemical evolution of melt and solid, I have developed a disequilibrium melting model for a one-dimensional upwelling mantle in which melt is produced, transported by porous flow and socked into chemically isolated channels. The model is based on recent disequilibrium melting models11,12, in which the residual melt in the porous flow system need not equilibrate with the residual solid. By changing the parameter values such as the rates of chemical equilibration and melt removal into channels, this model predicts trace element concentrations for various melting conditions, including disequilibrium effects which cannot be assessed quantitatively using previous models' for dynamic mantle melting1,6,13-15. Comparison between the model results and compositions of abyssal peridotites16 supports the idea that, if equilibrium melting is achieved, imperfect fractional melting (corresponding to 80% melt removal) occurs beneath mid-ocean ridges17,18. If disequilibrium melting is important, however, more efficient melt removal (in other words, chemical isolation from the residue) is required to explain the peridotite data.
RP IWAMORI, H (corresponding author), UNIV CAMBRIDGE,DEPT EARTH SCI,BULLARD LABS,MADINGLEY RD,CAMBRIDGE CB3 0EZ,ENGLAND.
NR 0
TC 72
Z9 77
U1 2
U2 23
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 23
PY 1993
VL 366
IS 6457
BP 734
EP 737
DI 10.1038/366734a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MN264
UT WOS:A1993MN26400025
DA 2026-03-10
ER

PT J
AU HSU, YT
   MOLDAY, RS
AF HSU, YT
   MOLDAY, RS
TI MODULATION OF THE CGMP-GATED CHANNEL OF ROD PHOTORECEPTOR CELLS BY CALMODULIN
SO NATURE
LA English
DT Article
ID free calcium-concentration; cyclic-gmp cascade; outer segments; retinal rods; guanylate-cyclase; binding-proteins; conductance; membranes; adaptation; mechanism
AB PHOTOBLEACHING of rhodopsin in rod photoreceptors activates the visual cascade system leading to a decrease in cyclic GMP and the closure of cGMP-gated channels in the rod outer segment plasma membrane1-4. Calcium plays an important role in the recovery of the rod outer segment to its dark state by regulating the resynthesis of cGMP by guanylate cyclase5-7. Here we report that calmodulin, a Ca2+-binding protein present in the rod outer segment8,9, increases the apparent Michaelis constant of the channel for cGMP. This results in a decrease in the rate of cation influx into the rod outer segment by two- to sixfold at low cGMP concentrations and has the effect of increasing the sensitivity of the channel to small changes in cGMP levels during phototransduction. Biochemical studies indicate that calcium-calmodulin binds to a protein of M(r) 240K which is tightly associated with the channel10. On the basis of these studies, Ca2+ is suggested to play a central role in photorecovery and light adaptation, not only by regulating guanylate cyclase, possibly through recoverin6,7, but also by modulating the cGMP-gated channel through calmodulin interaction with the 240K protein.
C1 UNIV BRITISH COLUMBIA, FAC MED, DEPT BIOCHEM, VANCOUVER V6T 1Z3, BC, CANADA.
C3 University of British Columbia
NR 30
TC 336
Z9 371
U1 0
U2 6
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 76
EP 79
DI 10.1038/361076a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800052
PM 7678445
DA 2026-03-10
ER

PT J
AU WILTSCHKO, W
   MUNRO, U
   FORD, H
   WILTSCHKO, R
AF WILTSCHKO, W
   MUNRO, U
   FORD, H
   WILTSCHKO, R
TI RED-LIGHT DISRUPTS MAGNETIC ORIENTATION OF MIGRATORY BIRDS
SO NATURE
LA English
DT Article
ID sockeye salmon; pigeons
AB THE transduction mechanisms and the neurophysiological basis of magnetoreception in birds are still largely unexplained, even though the role of the magnetic compass in the orientation of birds is fairly well understood1. The discussion on magnetoreception in birds and terrestrial vertebrates focuses mainly on two mechanisms: small particles of magnetite2,3 and biochemical bi-radical reactions of excited macromolecules4,5. When the bi-radical hypothesis was first proposed, magnetic resonance phenomena in the retina were suggested as the primary processes4, which led to the question of whether magnetoreception was light-dependent. Homing experiments6 and electrophysiological evidence7 from pigeons have produced evidence consistent with such a mechanism. An effect of the spectral composition of light on magnetic compass orientation in amphibians has recently been described8: under blue light of 450 nm and below, newts oriented as they did under the full spectrum, whereas they showed a roughly 90-degrees counter-clockwise shift when tested under wavelengths at or above 500 nm. Here we report the first orientation tests on migratory birds under light of different wavelengths; the results suggest a light-dependent process that appears to differ from that reported in newts.
C1 UNIV NEW ENGLAND,DEPT ZOOL,ARMIDALE,NSW 2351,AUSTRALIA.
C3 University of New England
RP WILTSCHKO, W (corresponding author), UNIV FRANKFURT,FACHBEREICH BIOL,SIESMAYERSTR 70,W-6000 FRANKFURT,GERMANY.
NR 20
TC 253
Z9 289
U1 0
U2 91
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 525
EP 527
DI 10.1038/364525a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700053
DA 2026-03-10
ER

PT J
AU ROENNEBERG, T
   MORSE, D
AF ROENNEBERG, T
   MORSE, D
TI 2 CIRCADIAN OSCILLATORS IN ONE CELL
SO NATURE
LA English
DT Article
ID gonyaulax-polyedra; rhythm
AB A CIRCADIAN clock, which continues to oscillate in constant conditions, is almost ubiquitous in eukaryotes as well as some prokaryotes1. This class of biological oscillators drives daily rhythms as diverse as photosynthesis in plants2 and the sleep-wake cycle in man3 and enables organisms to anticipate environmental changes or segregate in time-incompatible processes4. Circadian oscillators share many properties, suggesting that the clock is a single mechanism, preserved throughout evolution, which is capable of controlling all the different circadian functions. Here we show that two rhythms in a unicellular organism can, under certain experimental conditions, run independently, and thus each rhythm must be controlled by its own distinct oscillator.
C1 UNIV MONTREAL, INST RECH BIOL VEGETALE, MONTREAL H1X 2B2, PQ, CANADA.
C3 Universite de Montreal
RP ROENNEBERG, T (corresponding author), UNIV MUNICH, INST MED PSYCHOL, GOETHESTR 31, W-8000 MUNICH 2, GERMANY.
NR 26
TC 155
Z9 164
U1 0
U2 6
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 362
EP 364
DI 10.1038/362362a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600067
PM 29634015
DA 2026-03-10
ER

PT J
AU PODSIADLOWSKI, P
   HSU, JJL
   JOSS, PC
   ROSS, RR
AF PODSIADLOWSKI, P
   HSU, JJL
   JOSS, PC
   ROSS, RR
TI THE PROGENITOR OF SUPERNOVA-1993J - A STRIPPED SUPERGIANT IN A BINARY-SYSTEM
SO NATURE
LA English
DT Article
ID evolution; stars
AB SUPERNOVA 1993J in the spiral galaxy M81 is the brightest supernova since SN1987A and, like the latter, appears to be another 'peculiar' type II supernova. The available photometry1,2 of the supernova region before the explosion requires the presence of at least two supergiants (one of early spectral type and the other of late type), but the actual progenitor has yet to be identified. Here we show that the explosion of a late-type supergiant can explain the initial sharp peak in the supernova light curve, provided that the star had lost almost all of its hydrogen-rich envelope before the explosion. In our model, the secondary brightening of the supernova, approximately 10 days later, is then a consequence of the radioactive decay of Ni-56 and subsequently Co-56) produced in the explosion. The progenitor could have lost its hydrogen-rich envelope either in a strong stellar wind or, as seems more likely, through mass transfer to a companion star. In the latter case, the companion should reappear after the supernova photosphere has receded, the system having become a binary composed of a neutron star with a massive stellar companion.
C1 MIT,DEPT PHYS,CAMBRIDGE,MA 02139.
   UNIV CALIF BERKELEY,BERKELEY,CA 94720.
   MIT,DEPT SPACE RES,CAMBRIDGE,MA 02139.
   MIT,CTR THEORET PHYS,CAMBRIDGE,MA 02139.
   COLL HOLY CROSS,WORCESTER,MA 01610.
C3 Massachusetts Institute of Technology (MIT); University of California System; University of California Berkeley; Massachusetts Institute of Technology (MIT); Massachusetts Institute of Technology (MIT); College of the Holy Cross
RP PODSIADLOWSKI, P (corresponding author), UNIV CAMBRIDGE,INST ASTRON,CAMBRIDGE CB3 0HA,ENGLAND.
NR 16
TC 209
Z9 218
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 509
EP 511
DI 10.1038/364509a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700046
DA 2026-03-10
ER

PT J
AU SADOWSKI, HB
   GILMAN, MZ
AF SADOWSKI, HB
   GILMAN, MZ
TI CELL-FREE ACTIVATION OF A DNA-BINDING PROTEIN BY EPIDERMAL GROWTH-FACTOR
SO NATURE
LA English
DT Article
ID serum response element; signal transduction; 3t3 cells; fos; transcription; receptors; insulin; expression; induction; complex
AB GROWTH factors such as platelet-derived growth factor and epidermal growth factor (EGF) bind to and activate cell-surface receptors with intrinsic tyrosine kinase activities1. Receptor activation elicits multiple physiological changes in target cells, including alterations in gene expression2-4. Receptor tyrosine kinase signalling involves recruitment of proteins into a signalling complex through interactions between receptor autophosphorylation sites and the src-homology region-2 (SH2) domains on these signalling proteins5-9. Diverse signals can subsequently be generated, depending on the specific receptor and Cell type 2,10. How such signals are transmitted to the nucleus is poorly understood, but because the transcriptional activation of many genes by growth factors occurs in the absence of new protein synthesis4, one or more signals emanating from growth factor receptors must directly affect transcription factors. We report here the activation by EGF of a DNA-binding protein in a cell-free system where activation of DNA binding requires ligand, receptor, ATP and phosphotyrosine-SH2 interactions.
C1 COLD SPRING HARBOR LAB,BOX 100,1 BUNGTOWN RD,COLD SPRING HARBOR,NY 11724.
C3 Cold Spring Harbor Laboratory
NR 30
TC 247
Z9 257
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 79
EP 83
DI 10.1038/362079a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600066
PM 7680434
DA 2026-03-10
ER

PT J
AU ELDRED, GE
   LASKY, MR
AF ELDRED, GE
   LASKY, MR
TI RETINAL AGE PIGMENTS GENERATED BY SELF-ASSEMBLING LYSOSOMOTROPIC DETERGENTS
SO NATURE
LA English
DT Article
ID fast atom bombardment; mass-spectrometry; epithelium
AB A UNIVERSAL biomarker of cellular ageing in eukaryotic post-mitotic cells is the appearance over time of autofluorescent lysosomal residual bodies called age pigments or lipofuscin granules1. Their role in the process of cellular ageing has been debated without resolution2. Neither the identity nor mechanism of formation of the fluorophores has been definitively determined. A post-mitotic cell type that accumulates large quantities of age pigments is the ocular retinal pigment epithelium2. We have now identified the major orange-emitting fluorophore of these pigments using fast-atom bombardment tandem mass spectrometry with collisional activation analysis4. It is an amphoteric quaternary amine that arises as a Schiff base reaction product of retinaldehyde and ethanolamine. This compound should display lysosomotropic detergent behaviour which would help explain many of the age-related changes shown in this cell. These results suggest a new role for Schiff base reaction products as lysosomotropic amines in the genesis of cellular age pigments.
RP ELDRED, GE (corresponding author), UNIV MISSOURI, SCH MED, MASON INST OPHTHALMOL, COLUMBIA, MO 65212 USA.
NR 6
TC 410
Z9 450
U1 0
U2 13
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 724
EP 726
DI 10.1038/361724a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900056
PM 8441466
DA 2026-03-10
ER

PT J
AU VILLAREAL, TA
   ALTABET, MA
   CULVERRYMSZA, K
AF VILLAREAL, TA
   ALTABET, MA
   CULVERRYMSZA, K
TI NITROGEN TRANSPORT BY VERTICALLY MIGRATING DIATOM MATS IN THE NORTH PACIFIC-OCEAN
SO NATURE
LA English
DT Article
ID food web; pyrocystis-noctiluca; oligotrophic ocean; phytoplankton; fixation; sinking; nitrate; accumulation; abundance; growth
AB PHYTOPLANKTON production in the surface waters of stratified oceans is fed mainly by nitrogen that has been recycled within the euphotic zone1. The nitrogen that is lost from surface waters as organic matter exported to the deep ocean must be balanced by inputs of new nitrogen to the upper ocean2,3. Sediment trap studies2 have shown that the N-15/N-14 ratio (deltaN-15) of the exported organic matter is higher than that of the suspended particulates, and suggest that the rich nitrate pool below the euphotic zone is the source of 'new' nitrogen for the upper ocean. Yet steep vertical concentration gradients suggest that diffusive upward transport of nitrate is extremely limited, raising the question of how the nitrate reaches the surface waters. Here we present evidence that abundant diatom (Rhizosolenia) mats migrate vertically between surface waters and deep nitrate pools in the central North Pacific Ocean. Rising mats contain significantly larger internal nitrate pools than sinking mats. Mat deltaN-15 is similar to that of the sub-nitricline nitrate, and consistently heavier than that of near-surface particulate organic matter. We conclude that Rhizosolenia mats may transport the equivalent of 50% of the new nitrogen requirements into the surface waters of the North Pacific gyre.
C1 WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543.
   UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882.
C3 Woods Hole Oceanographic Institution; University of Rhode Island
RP VILLAREAL, TA (corresponding author), UNIV MASSACHUSETTS,ENVIRONM SCI PROGRAM,100 MORRISSEY BLVD,BOSTON,MA 02125, USA.
NR 45
TC 194
Z9 212
U1 0
U2 31
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 709
EP 712
DI 10.1038/363709a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900052
DA 2026-03-10
ER

PT J
AU NABEL, EG
   YANG, ZY
   PLAUTZ, G
   FOROUGH, R
   ZHAN, X
   HAUDENSCHILD, CC
   MACIAG, T
   NABEL, GJ
AF NABEL, EG
   YANG, ZY
   PLAUTZ, G
   FOROUGH, R
   ZHAN, X
   HAUDENSCHILD, CC
   MACIAG, T
   NABEL, GJ
TI RECOMBINANT FIBROBLAST GROWTH FACTOR-I PROMOTES INTIMAL HYPERPLASIA AND ANGIOGENESIS IN ARTERIES INVIVO
SO NATURE
LA English
DT Article
ID gene-expression invivo; endothelial-cells; proliferation; sequence; coronary; vessels; injury; wall
AB THE prototype members of the heparin-binding fibroblast growth factor (FGF) family1-6, acidic FGF (FGF-1) and basic FGF (FGF-2), are among the growth factors that act directly on vascular cells to induce endothelial cell growth and angiogenesis. In vivo, the role of the FGF prototypes in vascular pathology has been difficult to determine. We report here the introduction, by direct gene transfer into porcine arteries, of a eukaryotic expression vector encoding a secreted form of FGF-1. This somatic transgenic model defines gene function in the arterial wall in vivo. FGF-1 expression induced intimal thickening in porcine arteries 21 days after gene transfer, in contrast to control arteries transduced with an Escherichia coli beta-galactosidase gene. Where there was substantial intimal hyperplasia, neocapillary formation was detected in the expanded intima. These findings suggest that FGF-1 induces intimal hyperplasia in the arterial wall in vivo and, through its ability to stimulate angiogenesis in the neointima, FGF-1 could stimulate neovascularization of atherosclerotic plaques. Potentially, gene transfer of FGF-1 could also be used as a genetic intervention to improve blood flow to ischaemic tissues in selected clinical settings.
C1 UNIV MICHIGAN,MED CTR,HOWARD HUGHES MED INST,DEPT BIOL CHEM,ANN ARBOR,MI 48109.
   AMER RED CROSS,HOLLAND LAB,DEPT MOLEC BIOL,ROCKVILLE,MD 20855.
   AMER RED CROSS,HOLLAND LAB,DEPT EXPTL PATHOL,ROCKVILLE,MD 20855.
C3 University of Michigan System; University of Michigan; Howard Hughes Medical Institute; American Red Cross; American Red Cross
RP NABEL, EG (corresponding author), UNIV MICHIGAN,MED CTR,HOWARD HUGHES MED INST,DEPT INTERNAL MED,ANN ARBOR,MI 48109, USA.
NR 26
TC 340
Z9 385
U1 3
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 844
EP 846
DI 10.1038/362844a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300058
PM 7683112
DA 2026-03-10
ER

PT J
AU ECK, MJ
   SHOELSON, SE
   HARRISON, SC
AF ECK, MJ
   SHOELSON, SE
   HARRISON, SC
TI RECOGNITION OF A HIGH-AFFINITY PHOSPHOTYROSYL PEPTIDE BY THE SRC HOMOLOGY-2 DOMAIN OF P56(LCK)
SO NATURE
LA English
DT Article
ID signal transduction; pdgf receptor; kinase; proteins; gene
AB THE Src homology-2 (SH2) domains are modules of about 100 amino-acid residues that are found in many intracellular signal-transduction proteins1,2. They bind phosphotyrosine-containing sequences with high affinity and specificity1-4, recognizing phosphotyrosine in the context of the immediately adjacent polypeptide sequence3-12. The protein p56lck (Lck) is a Src-like, lymphocyte-specific tyrosine kinase13-15. A phosphopeptide library screen has recently been used to deduce an 'optimal' binding sequence for the Lck SH2 domain16. There is selectivity for the residues Glu, Glu and Ile in the three positions C-terminal to the phosphotyrosine. An 11-residue phosphopeptide derived from the hamster polyoma middle-T antigen, EPQpYEEIPIYL, binds with an approximately 1 nM dissociation constant to the Lck SH2 (ref. 17), an affinity equivalent to that of the tightest known SH2-phosphopeptide complex. We report here the high-resolution crystallographic analysis of the Lck SH2 domain in complex with this phosphopeptide. Recent crystallographically derived structures of the Src SH2 domain in complex with low-affinity peptides18, which do not contain the EEI consensus, and NMR-derived structures of unliganded Abl (ref. 19) and p85 (ref. 20) SH2 domains have revealed the conserved fold of the SH2 domain and the properties of a phosphotyrosine binding pocket. Our high-affinity complex shows the presence of a second pocket for the residue (pY + 3) three positions C-terminal to the phosphotyrosine (pY). The peptide is anchored by insertion of the pY and pY + 3 side chains into their pockets and by a network of hydrogen bonds to the peptide main chain. In the low-affinity phosphopeptide/Src complexes18, the pY + 3 residues do not insert into the homologous binding pocket and the peptide main chain remains displaced from the surface of the domain.
C1 CHILDRENS HOSP MED CTR,MOLEC MED LAB,BOSTON,MA 02115.
   HARVARD UNIV,SCH MED,DEPT MICROBIOL & MOLEC GENET,BOSTON,MA 02115.
   HARVARD UNIV,BRIGHAM & WOMENS HOSP,SCH MED,DEPT MED,JOSLIN DIABET CTR,DIV RES,BOSTON,MA 02115.
   HARVARD UNIV,DEPT BIOCHEM & MOLEC BIOL,CAMBRIDGE,MA 02138.
C3 Harvard University; Harvard University Medical Affiliates; Boston Children's Hospital; Harvard University; Harvard Medical School; Harvard University; Harvard Medical School; Harvard University Medical Affiliates; Brigham & Women's Hospital; Joslin Diabetes Center, Inc.; Harvard University
RP ECK, MJ (corresponding author), CHILDRENS HOSP MED CTR,HOWARD HUGHES MED INST,300 LONGWOOD AVE,BOSTON,MA 02115, USA.
NR 39
TC 502
Z9 543
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 87
EP 91
DI 10.1038/362087a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600068
PM 7680435
DA 2026-03-10
ER

PT J
AU SHEPPARD, DN
   RICH, DP
   OSTEDGAARD, LS
   GREGORY, RJ
   SMITH, AE
   WELSH, MJ
AF SHEPPARD, DN
   RICH, DP
   OSTEDGAARD, LS
   GREGORY, RJ
   SMITH, AE
   WELSH, MJ
TI MUTATIONS IN CFTR ASSOCIATED WITH MILD-DISEASE-FORM CL- CHANNELS WITH ALTERED PORE PROPERTIES
SO NATURE
LA English
DT Article
ID transmembrane conductance regulator; cystic-fibrosis gene; chloride channel; epithelial-cells; identification; expression; phosphorylation; membrane
AB THE cystic fibrosis transmembrane conductance regulator (CFTR) is a phosphorylation-regulated Cl- channel located in the apical membrane of epithelia1-10. Although cystic fibrosis (CF) is caused by mutations in a single gene encoding CFTR11,12, the disease has a variable clinical phenotype13,14. The most common mutation associated with cystic fibrosis, deletion of a phenylalanine at position 508 (frequency, 67%), is associated with severe disease15,17. But some missense mutations, for example ones in which arginine is replaced by histidine at residue at 117 (R117H; 0.8%), tryptophan at 334 (0.4%), or proline at 347 (0.5%), are associated with milder disease15,17,18. These missense mutations affect basic residues located at the external end of the second (M2) and in the sixth (M6) putative membrane-spanning sequences. Here we report that, when expressed in heterologous epithelial cells, all three mutants were correctly processed and generated cyclic AMP-regulated apical Cl- currents. Although the macroscopic current properties were normal, the amount of current was reduced. Patch-clamp analysis revealed that all three mutants had reduced single-channel conductances. In addition, R117H showed altered sensitivity to external pH and had altered single-channel kinetics. These results explain the quantitative decrease in macroscopic Cl- current, and suggest that R117, R334 and R347 contribute to the pore of the CFTR Cl- channel. Our results also suggest why R117H, R334W and R347P produce less severe clinical disease and have implications for our understanding of cystic fibrosis.
C1 UNIV IOWA,COLL MED,DEPT PHYSIOL & BIOPHYS,IOWA CITY,IA 52242.
   GENZYME CORP,FRAMINGHAM,MA 01701.
C3 University of Iowa; Sanofi-Aventis; Genzyme Corporation
RP SHEPPARD, DN (corresponding author), UNIV IOWA,COLL MED,DEPT INTERNAL MED,HOWARD HUGHES MED INST,IOWA CITY,IA 52242, USA.
NR 26
TC 427
Z9 486
U1 0
U2 20
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 160
EP 164
DI 10.1038/362160a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800061
PM 7680769
DA 2026-03-10
ER

PT J
AU PREVOT, M
   CAMPS, P
AF PREVOT, M
   CAMPS, P
TI ABSENCE OF PREFERRED LONGITUDE SECTORS FOR POLES FROM VOLCANIC RECORDS OF GEOMAGNETIC REVERSALS
SO NATURE
LA English
DT Article
ID french-polynesia; field; paths; magnetization; transition; sediments; geometry; polarity; sequence; islands
AB ACCORDING to a recent compilation of sedimentary records from the past 12 Myr, the reversing geomagnetic field displays a marked long-term longitudinal organization which seems to be correlated with the thermal structure of the lower mantle1. However, the crucial palaeomagnetic observation that intermediate virtual geomagnetic poles are preferentially confined to longitudes over the Americas or antipodal to this sector2,3 might be an artefact caused by distortion and smoothing of the geomagnetic signal by sediments4-6. Here we present a compilation of approximately 400 intermediate poles from 121 volcanic records of excursions and reversals less than 16 Myr old, sampled at various longitudes and latitudes, which does not confirm previous inferences1 and reinforces doubts4-6 about the ability of sediments to properly record a rapidly varying field. In contrast to virtual poles from excursions, those from reversals are uniformly distributed in longitude, which indicates that the reversing field is statistically axisymmetrical. Thus, we conclude that there is no evidence for control of transitional fields by the temperature distribution in the lowermost mantle.
C1 UNIV MONTPELLIER 2,F-34095 MONTPELLIER 05,FRANCE.
C3 Universite de Montpellier
RP PREVOT, M (corresponding author), CNRS,CTR GEOL & GEOPHYS,F-34095 MONTPELLIER 05,FRANCE.
NR 27
TC 103
Z9 104
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 53
EP 57
DI 10.1038/366053a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700051
DA 2026-03-10
ER

PT J
AU QIAN, HH
   DOWLING, JE
AF QIAN, HH
   DOWLING, JE
TI NOVEL GABA RESPONSES FROM ROD-DRIVEN RETINAL HORIZONTAL CELLS
SO NATURE
LA English
DT Article
ID gamma-aminobutyric-acid; receptor subtypes; molecular-biology; xenopus-oocytes; rat-brain; pharmacology; neurons; expression; invitro; cat
AB Gamma-AMINOBUTYRIC acid (GABA) is the main inhibitory neurotransmitter in the central nervous system. Two classes of GABA receptors (GABA(A) and GABA(B)) have been identified. GABA(A) receptors are ligand-gated chloride channels that are competitively antagonized by bicuculline, noncompetitively blocked by picrotoxin, and often allosterically modulated by barbiturates and benzodiazepines1-3. GABA(B) receptors regulate potassium and calcium channels through G-protein and intracellular second-messenger pathways2,3, are selectively activated by baclofen, and are antagonized by phaclofen and 2-hydroxysaclofen4,5. For some years, evidence has accumulated that there are GABA receptors, especially prominent along visual pathways, which are neither antagonized by bicuculline nor activated by baclofen, but are activated by certain conformationally restricted analogues of GABA, including cis-4-aminocrotonic acid (CACA)6-9. These receptors have been designated GABA(C) receptors9. As yet, membrane current responses from isolated neurons that reflect this novel pharmacology have not been reported, although such responses have been recorded from oocytes injected with retinal messenger RNA10-13. Here we describe a chloride-mediated current response from isolated rod-driven horizontal cells (H4) of the white perch retina that has this novel pharmacology.
RP QIAN, HH (corresponding author), HARVARD UNIV,DEPT CELLULAR & DEV BIOL,16 DIV AVE,CAMBRIDGE,MA 02138, USA.
NR 27
TC 256
Z9 282
U1 2
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 162
EP 164
DI 10.1038/361162a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600062
PM 8421521
DA 2026-03-10
ER

PT J
AU HENTSCHEL, U
   FELBECK, H
AF HENTSCHEL, U
   FELBECK, H
TI NITRATE RESPIRATION IN THE HYDROTHERMAL VENT TUBEWORM RIFTIA-PACHYPTILA
SO NATURE
LA English
DT Article
ID chemoautotrophic symbionts; bacterial symbiont; sulfide oxidation; worm; jones; vestimentifera; animals; cycle
AB THE vestimentiferan tubeworm Riftia packyptila is found around hydrothermal vent areas in the deep sea. Intracellular bacterial chemoautotrophic symbionts use the oxidation of sulphide from the effluent of the vents as an energy source for CO2 fixation. They apparently provide most or all of the nutritional requirements for their gutless hosts1-5. This kind of symbiosis has since been found in many other species from various other phyla from other habitats6-9. Here we present results that the bacteria of R. pachyptila may cover a significant fraction of their respiratory needs by the use of nitrate in addition to oxygen. Nitrate is reduced to nitrite, which may be the end product (nitrate respiration)10 or it may be further reduced to nitrogen gas (denitrification)11. This metabolic trait may have an important role in the colonization of hypoxic habitats in general by animals with this kind of symbiosis.
RP HENTSCHEL, U (corresponding author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,DIV MARINE BIOL RES 0202,LA JOLLA,CA 92093, USA.
NR 26
TC 64
Z9 70
U1 0
U2 33
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 338
EP 340
DI 10.1038/366338a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500047
DA 2026-03-10
ER

PT J
AU ZHANG, LH
   MURPHY, PJ
   KERR, A
   TATE, ME
AF ZHANG, LH
   MURPHY, PJ
   KERR, A
   TATE, ME
TI AGROBACTERIUM CONJUGATION AND GENE-REGULATION BY N-ACYL-L-HOMOSERINE LACTONES
SO NATURE
LA English
DT Article
ID structural identification; ti-plasmid; autoinducer; fischeri
AB CONJUGAL opines secreted by crown gall tumours induce strains of Agrobacterium tumefaciens that are donors of Ti plasmids to produce a diffusible conjugation factor1. This enhances the conjugal transfer efficiency of the Ti plasmid in other strains of A. tumefaciens. This factor behaves as a secondary messenger, transmitting the environmental information to tra genes. Here we report the use of spectrometry to show that this factor is identical to synthetic N-(beta-oxo-octan-1-oyl)-L-homoserine lactone and confirm that the synthetic compound is biologically active. N-(Hexan-1-oyl)-L-homoserine lactone has also been detected. A closely related molecule, N-(beta-oxo-hexan-1-oyl)-L-homoserine lactone, autoinduces bioluminescence in the distantly related bacterium, Vibrio fischeri2. N-Acyl-homoserine lactones thus seem to be conserved molecules in which the length and nature of the lipophilic acyl chain determines the biological function to be regulated. Mutants that do not produce the factor fail to conjugate unless supplied with it in the induction medium (our unpublished data). These data indicate that the conjugation factor is an autoinducer and a key signal molecule in the conjugation system of A. tumefaciens. It is, to our knowledge, the first example of a second messenger molecule in a bacterial conjugation system.
C1 UNIV ADELAIDE,WAITE AGR RES INST,DEPT CROP PROTECT,GLEN OSMOND,SA 5064,AUSTRALIA.
   UNIV ADELAIDE,WAITE AGR RES INST,DEPT PLANT SCI,GLEN OSMOND,SA 5064,AUSTRALIA.
C3 Adelaide University; University of Adelaide; Adelaide University; University of Adelaide
NR 11
TC 384
Z9 462
U1 0
U2 53
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 446
EP 448
DI 10.1038/362446a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400082
PM 8464475
DA 2026-03-10
ER

PT J
AU JOHNSON, WJ
   GOLDSTEIN, RH
AF JOHNSON, WJ
   GOLDSTEIN, RH
TI CAMBRIAN SEA-WATER PRESERVED AS INCLUSIONS IN MARINE LOW-MAGNESIUM CALCITE CEMENT
SO NATURE
LA English
DT Article
ID phanerozoic time; diagenesis; carbon
AB THE existence of temporal changes in the chemical composition of the oceans, which could provide constraints on the potential variability of the ocean-atmosphere system, remains an open question. Assessments of the chemistry of ancient oceans have relied largely on analysis of marine precipitates, generally carbonate and evaporite minerals1. These studies suggest that, whereas marine salinity has remained relatively stable over Phanerozoic time1, magnesium, calcium and sulphate concentrations of ancient oceans and CO2 partial pressure of ancient atmospheres may have changed2-4. The ratios of isotopes of carbon, oxygen, sulphur and strontium also appear to have varied 3,5,6. Here we present analyses of primary, one-phase fluid inclusions in Cambrian and Ordovician marine cements, which appear to represent aliquots of early Palaeozoic oceans. The cements have trace element, stable isotope and strontium isotope contents that are consistent with their having been precipitated in a Cambrian-Ordovician marine environment, and the fluids have marine salinities. As these (apparently primary) cements are low-magnesium calcite, unlike the predominantly high-magnesium calcite and aragonite of today's carbonate precipitates, the chemistry of the Cambrian ocean-atmosphere system seems to have been different from that of today.
RP JOHNSON, WJ (corresponding author), UNIV KANSAS,DEPT GEOL,LAWRENCE,KS 66045, USA.
NR 27
TC 46
Z9 47
U1 2
U2 20
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 335
EP 337
DI 10.1038/362335a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600057
PM 29634002
DA 2026-03-10
ER

PT J
AU WEISSMAN, JS
   KIM, PS
AF WEISSMAN, JS
   KIM, PS
TI EFFICIENT CATALYSIS OF DISULFIDE BOND REARRANGEMENTS BY PROTEIN DISULFIDE-ISOMERASE
SO NATURE
LA English
DT Article
ID pancreatic trypsin-inhibitor; disulfide isomerase; endoplasmic-reticulum; peptide binding; kinetic role; intermediate; resonance; bpti
AB PROTEIN disulphide isomerase (PDI)1,2 is a highly abundant and ubiquitous eukaryotic protein that is essential for viability in yeast3,4. Although PDI is thought to catalyse disulphide bond formation and isomerization during protein biosynthesis, PDI has been found previously to have only moderate effects (approximately 25-fold) on the rate of oxidative folding of proteins in vitro. In addition, PDI has been implicated in several apparently unrelated cellular functions3. For example, PDI is the beta-subunit of prolyl 4-hydroxylase 5 and is part of the trigylceride transfer complex6. The oxidative folding of bovine pancreatic trypsin inhibitor (BPTI) is slow and inefficient in vitro7-11. Here we report that PDI increases by a factor of 3,000-6,000 the rates of folding of kinetically trapped BPTI folding intermediates, in which native structure impedes disulphide bond formation. By contrast, PDI has only small effects on the rate of disulphide bond formation in intermediates that are oxidized readily in the absence of PDI. These results suggest that an important function of PDI is to catalyse disulphide bond formation and rearrangements within kinetically trapped, structured folding intermediates.
C1 MIT,DEPT BIOL,CAMBRIDGE,MA 02139.
C3 Massachusetts Institute of Technology (MIT)
RP WEISSMAN, JS (corresponding author), MIT,DEPT PHYS,WHITEHEAD INST BIOMED RES,HOWARD HUGHES MED INST,9 CAMBRIDGE CTR,CAMBRIDGE,MA 02139, USA.
NR 28
TC 205
Z9 225
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 185
EP 188
DI 10.1038/365185a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200055
PM 7690463
DA 2026-03-10
ER

PT J
AU ALTANGEREL, P
   NORELL, MA
   CHIAPPE, LM
   CLARK, JM
AF ALTANGEREL, P
   NORELL, MA
   CHIAPPE, LM
   CLARK, JM
TI FLIGHTLESS BIRD FROM THE CRETACEOUS OF MONGOLIA
SO NATURE
LA English
DT Article
AB THE Late Cretaceous rocks of Mongolia have produced unusual and phylogenetically important dinosaurs1,2. Here we report a startling new example, Mononychus olecranus gen. et sp. nov., an avialian theropod dinosaur with a short, robust forelimb possessing a single stout claw. Several features, including a carinate sternum and reduced fibula, suggest that Mononychus olecranus is more closely related to modern birds than is Archaeopteryx lithographica. The two skeletons are among the best preserved fossils known of a primitive bird, and emphasize the complexity of the morphological transformation from nonavialian theropods to modern birds. The occurrence of such a primitive bird in the Late Cretaceous reflects the paucity of Mesozoic bird fossils and suggests that the early radiation of avialians is only beginning to be sampled.
C1 AMER MUSEUM NAT HIST, DEPT VERTEBRATE PALEONTOL, 79TH ST & CPW, NEW YORK, NY 10024 USA.
   MONGOLIAN MUSEUM NAT HIST, ULAN BATOR 46, MONGOLIA.
C3 American Museum of Natural History (AMNH)
NR 20
TC 50
Z9 63
U1 1
U2 22
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 623
EP 626
DI 10.1038/362623a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800044
DA 2026-03-10
ER

PT J
AU THOMAS, HE
   STUNNENBERG, HG
   STEWART, AF
AF THOMAS, HE
   STUNNENBERG, HG
   STEWART, AF
TI HETERODIMERIZATION OF THE DROSOPHILA ECDYSONE RECEPTOR WITH RETINOID-X RECEPTOR AND ULTRASPIRACLE
SO NATURE
LA English
DT Article
ID response element; mammalian-cells; acid; superfamily; expression; proteins; product; member; family; genes
AB ECDYSONE in Drosophila has been a paradigm for steroid hormones since its ability to induce gene activity directly was demonstrated by its effects on moulting and polytene chromosome puffing1-3. The ecdysone receptor (EcR) was recently confirmed as a member of the nuclear receptor superfamily by cloning and characterization in a Drosophila cell line4. Here we show that EcR needs to heterodimerize with either the retinoid X receptor (RXR)5 or its Drosophila homologue, ultraspiracle (USP)6, for DNA binding and transactivation. These results place the ecdysone receptor in the heterodimerizing class of the nuclear receptor superfamily and demonstrate that the role of RXR/USP as a central and promiscuous partner in mediating the activity of these receptors7-12 is highly conserved. Whereas EcR-USP DNA-binding activity is unaffected by hormone, EcR-RXR DNA-binding activity is stimulated by either ecdysteroid or 9-cis-retinoic acid, demonstrating that hormone can play a role in heterodimer stabilization.
C1 EMBL,GENE EXPRESS PROGRAMME,MEYERHOFSTR 1,W-6900 HEIDELBERG,GERMANY.
C3 European Molecular Biology Laboratory (EMBL)
NR 29
TC 458
Z9 505
U1 1
U2 27
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 471
EP 475
DI 10.1038/362471a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400091
PM 8385270
DA 2026-03-10
ER

PT J
AU HAURI, EH
   SHIMIZU, N
   DIEU, JJ
   HART, SR
AF HAURI, EH
   SHIMIZU, N
   DIEU, JJ
   HART, SR
TI EVIDENCE FOR HOTSPOT-RELATED CARBONATITE METASOMATISM IN THE OCEANIC UPPER-MANTLE
SO NATURE
LA English
DT Article
ID trace-element; western victoria; lesser antilles; magma genesis; australia; system; origin; rocks; pb; peridotite
AB Four peridotite xenoliths from the islands of Savai'i (Western Samoa) and Tubuai (Austral Islands) contain primary olivine of lithospheric origin, and secondary assemblages of clinopyroxene + spinel +/- apatite. The trace-element contents of the secondary minerals show that they formed in equilibrium with carbonate-rich melts. Moreover, isotopic results indicate that these melts were derived from recycled crustal components in the convecting mantle, and place constraints on the origins of these components.
C1 UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,DIV GEOL RES 0208,LA JOLLA,CA 92093.
C3 University of California System; University of California San Diego; Scripps Institution of Oceanography
RP HAURI, EH (corresponding author), WOODS HOLE OCEANOG INST,DEPT GEOL & GEOPHYS,WOODS HOLE,MA 02543, USA.
NR 38
TC 375
Z9 400
U1 1
U2 57
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 221
EP 227
DI 10.1038/365221a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100044
DA 2026-03-10
ER

PT J
AU VON HELDEN, G
   GOTTS, NG
   BOWERS, MT
AF VON HELDEN, G
   GOTTS, NG
   BOWERS, MT
TI EXPERIMENTAL-EVIDENCE FOR THE FORMATION OF FULLERENES BY COLLISIONAL HEATING OF CARBON RINGS IN THE GAS-PHASE
SO NATURE
LA English
DT Article
ID ions; c-60; c60; buckminsterfullerene; clusters; shells
AB THE discovery1-6 of the spherical carbon cage compound buckminsterfullerene (C60) and the recent development of methods to produce it in bulk7 have led to an explosion in research in the physical and chemical properties of this unique species8,9. Nevertheless, the question of the formation mechanism of C60 (or of the other fullerenes) is still far from settled. We have shown elsewhere that carbon clusters in the gas phase develop from linear chains to planar ring systems to fullerenes as their size increases. One can easily envisage the transformation from chains to rings, but how the three-dimensional near-spherical fullerenes evolve from large planar rings is not obvious. Here we show that 'heating' these large ring systems above their 'melting' point leads to 100% fullerene formation accompanied by the evaporation of a small carbon fragment (C1 or C3 for odd systems and C2 for even systems). We propose a mechanism, based on these data, for efficient C60 production in carbon arcs.
C1 UNIV CALIF SANTA BARBARA, DEPT CHEM, SANTA BARBARA, CA 93106 USA.
C3 University of California System; University of California Santa Barbara
NR 28
TC 366
Z9 384
U1 0
U2 49
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 60
EP 63
DI 10.1038/363060a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200056
DA 2026-03-10
ER

PT J
AU VETRIE, D
   VORECHOVSKY, I
   SIDERAS, P
   HOLLAND, J
   DAVIES, A
   FLINTER, F
   HAMMARSTROM, L
   KINNON, C
   LEVINSKY, R
   BOBROW, M
   SMITH, CIE
   BENTLEY, DR
AF VETRIE, D
   VORECHOVSKY, I
   SIDERAS, P
   HOLLAND, J
   DAVIES, A
   FLINTER, F
   HAMMARSTROM, L
   KINNON, C
   LEVINSKY, R
   BOBROW, M
   SMITH, CIE
   BENTLEY, DR
TI THE GENE INVOLVED IN X-LINKED AGAMMAGLOBULINEMIA IS A MEMBER OF THE SRC FAMILY OF PROTEIN-TYROSINE KINASES
SO NATURE
LA English
DT Article
ID transcribed sequences; dna fragments; close linkage; genomic dna; features; identification; expression; selection; mutations; pp60v-src
AB X-linked agammaglobulinaemia (XLA) is a human immunodeficiency caused by failure of pre-B cells in the bone marrow to develop into circulating mature B cells. A novel gene has been isolated which maps to the XLA locus, is expressed in B cells, and shows mutations in families with the disorder. The gene is a member of the src family of proto-oncogenes which encode protein-tyrosine kinases. This is, to our knowledge, the first evidence that mutations in a src-related gene are involved in human genetic disease.
C1 KAROLINSKA INST, NOVUM, CTR BIOTECHNOL, S-14157 HUDDINGE, SWEDEN.
   UMEA UNIV, APPL CELL & MOLEC BIOL UNIT, S-90187 UMEA, SWEDEN.
   INST CHILD HLTH, MOLEC IMMUNOL UNIT, LONDON WC1N 1EH, ENGLAND.
C3 Karolinska Institutet; Umea University; University of London; University College London
RP VETRIE, D (corresponding author), UMDS GUYS & ST THOMASS HOSP, DIV MED & MOLEC GENET, GUYS TOWER, LONDON SE1 9RT, ENGLAND.
FU Wellcome Trust Funding Source: Medline
NR 62
TC 1294
Z9 1426
U1 1
U2 42
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 226
EP 233
DI 10.1038/361226a0
PG 8
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400048
PM 8380905
DA 2026-03-10
ER

PT J
AU FU, XD
AF FU, XD
TI SPECIFIC COMMITMENT OF DIFFERENT PREMESSENGER RNAS TO SPLICING BY SINGLE SR PROTEINS
SO NATURE
LA English
DT Article
ID tract-binding protein; polypyrimidine tract; conserved family; factor sc35; complexes; components; nucleus; site; sf2; u1
AB HIGHER eukaryotic cells express a family of essential splicing factors with a characteristic RNA-binding domain and serine/arginine-rich (SR) motif. These SR proteins, which include SC35(2-6) and SF2/ASF7-12, are conserved from Drosophila to man, are required for early steps of spliceosome assembly, and can influence splice-site selections. To address their mechanisms of action, SR proteins were examined for their role in committing pre-messenger RNA to the splicing pathway.  I report here that SC35 was sufficient on its own to form a committed complex with human beta-globin pre-mRNA. Examination of other SR proteins and pre-mRNA substrates revealed that single SR proteins committed different pre-mRNAs to splicing with pronounced substrate specificity. These results suggest that splicing of different pre-mRNAs may require distinct sets of SR proteins, and that the commitment by SR proteins may be a critical step at which alternative and tissue-specific splicing is regulated.
RP FU, XD (corresponding author), UNIV CALIF SAN DIEGO,DIV CELLULAR & MOLEC MED,9500 GILMAN DR,LA JOLLA,CA 92093, USA.
NR 25
TC 258
Z9 293
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 82
EP 85
DI 10.1038/365082a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600060
PM 8361546
DA 2026-03-10
ER

PT J
AU SOLLNER, T
   WHITEHART, SW
   BRUNNER, M
   ERDJUMENTBROMAGE, H
   GEROMANOS, S
   TEMPST, P
   ROTHMAN, JE
AF SOLLNER, T
   WHITEHART, SW
   BRUNNER, M
   ERDJUMENTBROMAGE, H
   GEROMANOS, S
   TEMPST, P
   ROTHMAN, JE
TI SNAP RECEPTORS IMPLICATED IN VESICLE TARGETING AND FUSION
SO NATURE
LA English
DT Article
ID central nervous-system; vesicular transport; membrane-protein; secretory pathway; synaptic vesicles; golgi stack; yeast; genes; family; purification
AB The N-ethylmaleimide-sensitive fusion protein (NSF) and the soluble NSF attachment proteins (SNAPs) appear to be essential components of the intracellular membrane fusion apparatus. An affinity purification procedure based on the natural binding of these proteins to their targets was used to isolate SNAP receptors (SNAREs) from bovine brain. Remarkably, the four principal proteins isolated were all proteins associated with the synapse, with one type located in the synaptic vesicle and another in the plasma membrane, suggesting a simple mechanism for vesicle docking. The existence of numerous SNARE-related proteins, each apparently specific for a single kind of vesicle or target membrane, indicates that NSF and SNAPs may be universal components of a vesicle fusion apparatus common to both constitutive and regulated fusion (including neurotransmitter release), in which the SNAREs may help to ensure vesicle-to-target specificity.
RP SOLLNER, T (corresponding author), MEM SLOAN KETTERING CANC CTR,ROCKEFELLER RES LAB,1275 YORK AVE,NEW YORK,NY 10021, USA.
NR 56
TC 2770
Z9 3215
U1 5
U2 358
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 318
EP 324
DI 10.1038/362318a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600051
PM 8455717
DA 2026-03-10
ER

PT J
AU SOLA, SM
   KOHLER, M
AF SOLA, SM
   KOHLER, M
TI RECENT DISCOVERIES OF DRYOPITHECUS SHED NEW LIGHT ON EVOLUTION OF GREAT APES
SO NATURE
LA English
DT Article
ID clade
AB THE origin and early evolution of the great ape/human clade (Hominidae) is currently a subject of debate1-3. The controversy is fuelled by the fragmentary nature of the fossils which renders it difficult to determine clearly derived features that permit the recognition of fossil members of this clade. We report here the recent discovery of a facial skeleton and a temporal fragment with the petrosal bone of Dryopithecus laietanus, which provides a way out of an impasse. The lack of the fossa subarcuata is a great ape and human clade synapomorphy, and proves unequivocally that Dryopithecus belongs to this clade. The zygomatic possesses derived characters which reveal that Dryopithecus is related to the Ponginae and not to the African apes/humans, as recently suggested1. The remaining morphological features are plesiomorphic and thus provide a good model of a common ancestor of all Hominidae.
RP SOLA, SM (corresponding author), ESCOLA IND 23,INST PALEONTOL M CRUSAFONT,E-08201 SABADELL,SPAIN.
NR 13
TC 46
Z9 54
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 543
EP 545
DI 10.1038/365543a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100052
PM 8413607
DA 2026-03-10
ER

PT J
AU TOUMI, R
   JONES, RL
   PYLE, JA
AF TOUMI, R
   JONES, RL
   PYLE, JA
TI STRATOSPHERIC OZONE DEPLETION BY CIONO2 PHOTOLYSIS
SO NATURE
LA English
DT Article
ID antarctic ozone; chlorine
AB SPRINGTIME ozone depletion over Antarctica is thought1,2 to be due to catalytic cycles involving chlorine monoxide, which is formed as a result of reactions on the surface of polar stratospheric clouds (PSCs).  When the PSCs evaporate, ClO in the polar air can react with NO2 to form the reservoir species ClONO2. High concentrations of ClONO2 can also be found at lower latitudes because of direct transport of polar air or mixing of ClO and NO2 at the edges of the polar vortex. ClONO2 can take part in an ozone-depleting catalytic cycle18, but the significance of this cycle has not been clear. Here we present model simulations of ozone concentrations from March to May both within the Arctic vortex and at a mid-latitude Northern Hemisphere site. We find increasing ozone loss from March to May. The ClONO2 cycle seems to be responsible for a significant proportion of the simulated ozone loss. An important aspect of this cycle is that it is not as limited as the other chlorine cycles to the timing and location of PSCs; it may therefore play an important role in ozone depletion at warm middle latitudes.
RP TOUMI, R (corresponding author), UNIV CAMBRIDGE,CTR ATMOSPHER SCI,DEPT CHEM,LENSFIELD RD,CAMBRIDGE CB2 1EW,ENGLAND.
NR 18
TC 52
Z9 53
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 37
EP 39
DI 10.1038/365037a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600046
DA 2026-03-10
ER

PT J
AU CHILDRESS, JJ
   LEE, RW
   SANDERS, NK
   FELBECK, H
   OROS, DR
   TOULMOND, A
   DESBRUYERES, D
   KENNICUTT, MC
   BROOKS, J
AF CHILDRESS, JJ
   LEE, RW
   SANDERS, NK
   FELBECK, H
   OROS, DR
   TOULMOND, A
   DESBRUYERES, D
   KENNICUTT, MC
   BROOKS, J
TI INORGANIC CARBON UPTAKE IN HYDROTHERMAL VENT TUBEWORMS FACILITATED BY HIGH ENVIRONMENTAL PCO2
SO NATURE
LA English
DT Article
ID riftia-pachyptila jones; tube-worm; rose garden; galapagos rift; blood; field
AB THE marine invertebrate Riftia pachyptila has a remarkable symbiosis with intracellular carbon-fixing sulphide-oxidizing bacteria which was first discovered at 2,450 m depth on the Galapagos Rift1-4. Such symbiotic arrangements have since been found in a variety of invertebrate taxa and habitat5,6. Studies of these symbioses have focused on temperature, sulphide and oxygen as critical environmental parameters5,7-9. As Riftia has a high growth rate and its symbionts are far removed from the host surface10,11, inorganic carbon supply to the symbionts has been recognized as a problem and host mechanisms to concentrate inorganic carbo have been posited12,13. Increased environmental CO2 partial pressure (pCO2) has not seriously been considered as a critical environmental parameter7,14. Here we report that elevated pCO2 (2.9 kPa) in the worms' environment is a determinant of internal total CO2 (SIGMACO2) and pCO2, facilitating CO2 transport and diffusion to the symbionts. We propose that elevated pCO2 is a potentially critical environmental factor for this species as well as for other chemoautotrophic symbioses.
C1 UNIV CALIF SANTA BARBARA,INST MARINE SCI,SANTA BARBARA,CA 93106.
   NE MISSOURI STATE UNIV,DIV SCI,KIRKSVILLE,MO 63501.
   UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,MARINE BIOL RES DIV,LA JOLLA,CA 92093.
   UNIV PARIS 06,BIOL MARINE LAB,F-75252 PARIS 05,FRANCE.
   CNRS,LP4601,F-29682 ROSCOFF,FRANCE.
   IFREMER,CTR BREST,DEPT ENVIRONM PROFOND,F-29280 PLOUZANE,FRANCE.
   TEXAS A&M UNIV SYST,GEOCHEM & ENVIRONM RES GRP,COLL STN,TX 77845.
C3 University of California System; University of California Santa Barbara; University of California System; University of California San Diego; Scripps Institution of Oceanography; Sorbonne Universite; Centre National de la Recherche Scientifique (CNRS); Ifremer; Texas A&M University System; Texas A&M University College Station
RP CHILDRESS, JJ (corresponding author), UNIV CALIF SANTA BARBARA,DEPT BIOL SCI,SANTA BARBARA,CA 93106, USA.
NR 30
TC 81
Z9 85
U1 0
U2 23
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 147
EP 149
DI 10.1038/362147a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800056
DA 2026-03-10
ER

PT J
AU COUTAVAS, E
   REN, MD
   OPPENHEIM, JD
   DEUSTACHIO, P
   RUSH, MG
AF COUTAVAS, E
   REN, MD
   OPPENHEIM, JD
   DEUSTACHIO, P
   RUSH, MG
TI CHARACTERIZATION OF PROTEINS THAT INTERACT WITH THE CELL-CYCLE REGULATORY PROTEIN RAN/TC4
SO NATURE
LA English
DT Article
ID rcc1; polypeptide; expression; mitosis; gtpase; genes
AB THE human Ras-related nuclear protein Ran/TC4 (refs 1-4) is the prototype of a well conserved family of GTPases that can regulate both cell-cycle progression5-8 and messenger RNA transport9. Ran has been proposed to undergo tightly controlled cycles of GTP binding and hydrolysis, to operate as a GTPase switch10,11 whose GTP- and GDP-bound forms interact differentially with regulators and effectors. One known regulator, the protein RCC1 (refs 12, 13), interacts with Ran to catalyse guanine nucleotide exchange, and both RCC1 and Ran are components of an intrinsic checkpoint control that prevents the premature initiation of mitosis. To test and extend the GTPase-switch model, we searched for a Ran-specific GTPase-activating protein (GAP), and for putative effectors (proteins that interact specifically with Ran/TC4-GTP). We report here the identification of a Ran GAP and its use to characterize the GTP-hydrolysing properties of mutant Ran proteins, and the identification and cloning of a binding protein specific for Ran/TC4-GTP.
C1 NYU MED CTR,DEPT BIOCHEM,NEW YORK,NY 10016.
   NYU MED CTR,DEPT CELL BIOL,NEW YORK,NY 10016.
   NYU MED CTR,DEPT MICROBIOL,NEW YORK,NY 10016.
   NYU MED CTR,KAPLAN CTR,NEW YORK,NY 10016.
C3 New York University; New York University; New York University; New York University
NR 23
TC 247
Z9 261
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 585
EP 587
DI 10.1038/366585a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800076
PM 8255297
DA 2026-03-10
ER

PT J
AU KITSBERG, D
   SELIG, S
   KESHET, I
   CEDAR, H
AF KITSBERG, D
   SELIG, S
   KESHET, I
   CEDAR, H
TI REPLICATION STRUCTURE OF THE HUMAN BETA-GLOBIN GENE DOMAIN
SO NATURE
LA English
DT Article
ID dihydrofolate-reductase domain; dna-replication; chromosome-replication; nucleosome segregation; mammalian-cells; origin; locus; identification; activation; element
AB THE animal cell genome is organized into a series of replicons with an average size of 50-300 kilobases1; each of these units is characterized by its own origin of replication which serves as the point of initiation for DNA synthesis. In animal viruses, origin usage can be regulated by cis-acting elements2, and in some cases, replication may be cell-type specific3. Little is known, however, about the organization and control of endogenous tissue-specific gene replication. To understand this process, we have used a replication direction assay to examine DNA fragments covering more than 200 kilobases of the human beta-like globin domain, and have identified a single bidirectional origin located upstream of the beta-globin itself. This locus is used to initiate DNA synthesis in expressing cells, where the globin domain replicates early, and in non-expressing cells, which are characterized by late replication of the same region4,5. Deletion of this origin sequence, as occurs in the haemoglobin Lepore syndrome6, cancels bidirectional DNA synthesis at this site and leads to a striking reversal of replication direction upstream to the locus. This represents the first genetic proof of the existence of specific, discrete origins of replication in animal cells.
RP KITSBERG, D (corresponding author), HEBREW UNIV JERUSALEM,SCH MED,DEPT CELLULAR BIOCHEM,IL-91010 JERUSALEM,ISRAEL.
NR 25
TC 260
Z9 290
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 588
EP 590
DI 10.1038/366588a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800077
PM 8255298
DA 2026-03-10
ER

PT J
AU STETTER, KO
   HUBER, R
   BLOCHL, E
   KURR, M
   EDEN, RD
   FIELDER, M
   CASH, H
   VANCE, I
AF STETTER, KO
   HUBER, R
   BLOCHL, E
   KURR, M
   EDEN, RD
   FIELDER, M
   CASH, H
   VANCE, I
TI HYPERTHERMOPHILIC ARCHAEA ARE THRIVING IN DEEP NORTH-SEA AND ALASKAN OIL-RESERVOIRS
SO NATURE
LA English
DT Article
ID sp-nov represents; gen-nov; archaebacteria; bacteria; 105-degrees-c; organisms
AB HOT springs and hydrothermal vents harbour hyperthermophilic archaea and bacteria with the highest growth temperatures known1-6. Here we report the discovery of high concentrations of hyperthermophiles in the production fluids from four oil reservoirs about 3,000 metres below the bed of the North Sea and below the permafrost surface of the North Slope of Alaska. Enrichment cultures of sulphidogens grew at 85-degrees-C and 102-degrees-C, which are similar to in situ reservoir temperatures7,8. Some species were identical to those from submarine hot vents and may have entered the reservoirs in injected sea water. Several enrichments grew anaerobically in sterilized artificial sea water with crude oil as the single carbon and energy source. These hyperthermophiles may be part of novel high-temperature communities and could be responsible for in situ bioconversions of crude oil fractions at temperatures previously considered too extreme for biochemical reactions4,7,9,10.
C1 UMIST,CAPCIS LTD,MANCHESTER M1 2PW,ENGLAND.
   BP EXPLORAT OPERATING CO LTD,ABERDEEN AB2 0PB,SCOTLAND.
   BP RES,WARRENSVILLE RES & ENVIRONM SCI CTR,CLEVELAND,OH 44128.
   UNIV REGENSBURG,ARCHAEENZENTRUM,D-93053 REGENSBURG,GERMANY.
C3 University of Manchester; BP; BP; University of Regensburg
RP STETTER, KO (corresponding author), UNIV REGENSBURG,LEHRSTUHL MIKROBIOL,UNIV STR 31,D-93053 REGENSBURG,GERMANY.
NR 22
TC 361
Z9 411
U1 1
U2 47
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 743
EP 745
DI 10.1038/365743a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200059
DA 2026-03-10
ER

PT J
AU BERG, BA
AF BERG, BA
TI LOCATING GLOBAL MINIMA IN OPTIMIZATION PROBLEMS BY A RANDOM-COST APPROACH
SO NATURE
LA English
DT Article
AB OPTIMIZATION problems are common to many diverse disciplines. The classic example is the travelling-salesman problem1,2, in which the objective is to find the shortest path connecting a number of cities. Spin glasses3, meanwhile, exemplify a general class of systems subject to conflicting constraints: in this case, the impossibility of each spin in a lattice aligning favourably with all of its neighbours leads to 'frustration' and to a large number of local energy minima. The optimization problem then becomes the attempt to find the global minimum, or ground state. Predicting the conformational ground state of proteins4 is closely allied to the spin-glass problem. The chief difficulty in searching for global minima is that straightforward search algorithms1 tend to become trapped in local minima. Only a few promising approaches, such as simulated annealing2 or genetic algorithms5, exist. Here I present a general purpose Monte Carlo procedure in which local redirections of the search path are effected at all relevant length scales while enforcing a one-dimensional random walk in the function being minimized. This method yields a series of extrema, from which the global minimum can be extracted with high probability in the limit of large statistics.
RP BERG, BA (corresponding author), INST ADV STUDY BERLIN,WALLOTSTR 19,W-1000 BERLIN 33,GERMANY.
NR 13
TC 68
Z9 72
U1 0
U2 14
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 708
EP 710
DI 10.1038/361708a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900049
DA 2026-03-10
ER

PT J
AU DRISCOLL, J
   BROWN, MG
   FINLEY, D
   MONACO, JJ
AF DRISCOLL, J
   BROWN, MG
   FINLEY, D
   MONACO, JJ
TI MHC-LINKED LMP GENE-PRODUCTS SPECIFICALLY ALTER PEPTIDASE ACTIVITIES OF THE PROTEASOME
SO NATURE
LA English
DT Article
ID major histocompatibility complex; class-ii region; multicatalytic proteinase; antigen presentation; subunits; pathway; cells
AB PROTEASOMES are highly conserved macromolecular structures which function as endopeptidases1-3. They are found in the cytoplasm and nucleus of eukaryotic tissues and consist of at least 14 non-identical subunits with molecular masses ranging from approximately 20 to 32K. Proteasomes are essential in the selective degradation of ubiquitinated and certain non-ubiquitinated proteins, acting as the proteolytic core of an energy-dependent 26S (1,500K) proteolytic complex. Two proteasome subunits, LMP2 and LMP7 (refs 4-7), are encoded within the major histocompatibility complex (MHC), implicating proteasomes in antigen processing8-9. Here we determine the function of these two MHC-linked subunits by comparing the proteolytic activities of purified proteasomes containing (LMP+) or lacking (LMP-) these components. We find that proteasomes of both types have endopeptidase activity against substrates bearing hydrophobic, basic or acidic residues immediately preceding the cleavage site (the P1 position) and at sites following asparagine, glycine and proline residues. The activity of LMP+ proteasomes is much higher than that of LMP- proteasomes against substrates with hydrophobic, basic or asparagine residues at P1, whereas their activities are comparable when acidic and glycine residues are present at P1. The MHC-linked LMP2 and LMP7 subunits therefore function to amplify specific endopeptidase activities of the proteasome.
C1 HARVARD UNIV,SCH MED,DEPT CELLULAR & MOLEC PHYSIOL,BOSTON,MA 02115.
   VIRGINIA COMMONWEALTH UNIV,MED COLL VIRGINIA,DEPT MICROBIOL & IMMUNOL,RICHMOND,VA 23298.
C3 Harvard University; Harvard Medical School; Virginia Commonwealth University
NR 21
TC 444
Z9 480
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 262
EP 264
DI 10.1038/365262a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100057
PM 8371781
DA 2026-03-10
ER

PT J
AU WIENS, DA
   MCGUIRE, JJ
   SHORE, PJ
AF WIENS, DA
   MCGUIRE, JJ
   SHORE, PJ
TI EVIDENCE FOR TRANSFORMATIONAL FAULTING FROM A DEEP DOUBLE SEISMIC ZONE IN TONGA
SO NATURE
LA English
DT Article
ID downgoing lithosphere; spinel transitions; focus earthquakes; subduction zone; high-pressure; olivine; mantle; mechanism; evolution; beneath
AB DOUBLE seismic zones, planes or earthquakes parallel to the dip of a subducting slab and separated by 2040 km, provide important clues about the earthquake generating mechanisms and strain distribution inside subducting slabs. Double seismic zones have been found at intermediate depths (70-200 km) in many subduction zones1-6 but have not been previously reported in deep slabs. Here, by relocating earthquakes with a hypocentroidal decomposition technique7 and visualizing the earthquake positions and uncertainties in three dimensions, we identify a double seismic zone at depths of 350-460 km in the Tonga subduction zone. Source parameters of the earthquakes determined by waveform analysis suggest different stress orientations for the two zones, with in-plane compression in the lower zone and in-plane tension in the upper zone. The double zone may be due to transformational faulting, as olivine along the edges of a metastable olivine wedge becomes warmer and transforms to spinel8-11.
RP WIENS, DA (corresponding author), WASHINGTON UNIV,DEPT EARTH & PLANETARY SCI,ST LOUIS,MO 63130, USA.
NR 32
TC 93
Z9 106
U1 0
U2 24
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 790
EP 793
DI 10.1038/364790a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100052
DA 2026-03-10
ER

PT J
AU SAHA, S
   BRICKMAN, JM
   LEHMING, N
   PTASHNE, M
AF SAHA, S
   BRICKMAN, JM
   LEHMING, N
   PTASHNE, M
TI NEW EUKARYOTIC TRANSCRIPTIONAL REPRESSORS
SO NATURE
LA English
DT Article
ID major late promoter; rna polymerase-ii; yeast; activators; drosophila; protein; invitro; dorsal; initiation; sequences
AB TRANSCRIPTIONAL activating sequences have been described1 that are encoded by parts of the genome of Escherichia coli. These acidic peptides, fused to a DNA-binding fragment of the yeast transcriptional activator GAL4, activate transcription of a gene in a wide array of eukaryotes, provided that gene bears GAL4-binding sites nearby2-4. Here we describe an E. coli-encoded sequence that, when attached to the same DNA-binding fragment (GAL4(1-147)), converts that fragment into a repressor. Thus, as assayed in yeast or in vitro in yeast extracts, this molecule represses transcription when bound upstream of a variety of different activators. Two additional repressing regions that work when tethered upstream, a multiple mutant derivative of the original isolate and a synthetic peptide are, like the original isolate, highly basic. At least one activator can be inhibited by the mutant but not by the parental repressing region. These and other findings suggest that these repressing regions interact with and inhibit the activity of activating regions bound nearby on DNA.
C1 HARVARD UNIV,DEPT BIOCHEM & MOLEC BIOL,CAMBRIDGE,MA 02138.
C3 Harvard University
NR 23
TC 86
Z9 91
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 648
EP 652
DI 10.1038/363648a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900062
PM 8510759
DA 2026-03-10
ER

PT J
AU SINGER, MC
   PARMESAN, C
AF SINGER, MC
   PARMESAN, C
TI SOURCES OF VARIATIONS IN PATTERNS OF PLANT INSECT ASSOCIATION
SO NATURE
LA English
DT Article
ID genetic-variation; host range; populations; preference; evolution
AB MODELS of evolution in parasite-host or predator-prey systems assume that particular pairs of species either always interact or never interact1. But, in nature, a particular parasite species may interact with a particular host species at some times (or in some places) but not at others, even if host availability is not variable. These differences could stem either from variation among conspecific hosts in their resistance to parasitism or from variation among conspecific parasites in their tendency to attack particular host species. We report here that both of these effects exist, that they are probably due to genetic variation both in parasites and in hosts, and that they interact to produce spatial variation in ecological relationships. We studied three potentially interacting species, a herbivorous insect and two of its potential host plants, at each of two sites. At one site, a plant species was avoided by the insects because of a combination of local insect preference and local plant resistance. This result shows that the diet is a property neither of the parasite nor of the host, but of the parasite-host interaction.
C1 UNIV TEXAS,DIV BIOL SCI,AUSTIN,TX 78712.
C3 University of Texas System; University of Texas Austin
RP SINGER, MC (corresponding author), UNIV TEXAS,DEPT ZOOL,AUSTIN,TX 78712, USA.
NR 20
TC 74
Z9 80
U1 0
U2 26
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 251
EP 253
DI 10.1038/361251a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400056
DA 2026-03-10
ER

PT J
AU WHITFIELD, LS
   LOVELLBADGE, R
   GOODFELLOW, PN
AF WHITFIELD, LS
   LOVELLBADGE, R
   GOODFELLOW, PN
TI RAPID-SEQUENCE EVOLUTION OF THE MAMMALIAN SEX-DETERMINING GENE SRY
SO NATURE
LA English
DT Article
ID y-chromosome; nucleotide substitution; determining region; dna; selection; protein; zfy
AB IN mammals, induction of male sex determination requires the Y-chromosome gene SRY1. SRY encodes a protein with a central 'high mobility group' domain (HMG box) of about 78 amino acids1-3 . HMG boxes are found in a wide variety of proteins that bind to DNA with high affinity but differing degrees of sequence specificity4. The human SRY protein binds to linear DNA with sequence specificity5 and to cruciform DNA structures without sequence specificity6. The DNA-binding activity of the SRY protein resides in the HMG box and mutations in this region are associated with sex reversal in XY females6-8. No function has been ascribed to the portions of the SRY protein outside the HMG box. SRY belongs to a family of genes that are related by sequence homology within the DNA-binding domain: the genes most similar to SRY (>60%) have been named SOX genes (SRY box genes). None of the known SOX genes is homologous to SRY outside the HMG-box region. Although SRY is an important developmental regulator, its sequence is poorly conserved between species apart from the HMG-box domain. Here we investigate the coding sequence of SR Y in primates and find that evolution has been rapid in the regions flanking the conserved domain. The high degree of sequence divergence and the frequency of non-synonymous mutations suggest either that the majority of the coding sequence has no functional significance or that directional selection has occurred.
C1 NATL INST MED RES, MRC, EUKARYOT MOLEC GENET LAB, LONDON NW7 1AA, ENGLAND.
C3 MRC National Institute for Medical Research
RP WHITFIELD, LS (corresponding author), UNIV CAMBRIDGE, DEPT GENET, DOWNING ST, CAMBRIDGE CB2 2EH, ENGLAND.
FU Medical Research Council [MC_U117562207] Funding Source: Medline; Wellcome Trust Funding Source: Medline
NR 22
TC 343
Z9 397
U1 2
U2 26
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 713
EP 715
DI 10.1038/364713a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700056
PM 8355783
DA 2026-03-10
ER

PT J
AU VERA, JC
   RIVAS, CI
   FISCHBARG, J
   GOLDE, DW
AF VERA, JC
   RIVAS, CI
   FISCHBARG, J
   GOLDE, DW
TI MAMMALIAN FACILITATIVE HEXOSE TRANSPORTERS MEDIATE THE TRANSPORT OF DEHYDROASCORBIC ACID
SO NATURE
LA English
DT Article
ID border membrane-vesicles; xenopus-laevis oocytes; l-ascorbate transport; glucose-transporter; functional expression; leukocytes; kidney; fibroblasts; deficiency; intestine
AB ALTHOUGH vitamin C is critical to human physiology1-5, it is not clear how it is taken up into cells. The kinetics of cell and tissue accumulation of ascorbic acid in vitro indicate that the process is mediated by specific transporters at the cell membrane6. Some experimental observations have linked the transport of ascorbic acid with hexose transport systems in mammalian cells, although no clear information is available regarding the specific role(s) of these transporters, if any, in this process7-16. Here we use the Xenopus laevis oocyte expression system to show that the mammalian facilitative hexose transporters are efficient transporters of the oxidized form of vitamin C (dehydroascorbic acid). Two transport pathways, one with low affinity and one with high affinity for dehydroascorbic acid, were found in oocytes expressing the mammalian transporters, and these oocytes accumulated vitamin C against a concentration gradient when supplied with dehydroascorbic acid. We obtained similar results in experiments using normal human neutrophils. These observations indicate that mammalian facilitative hexose transporters are a physiologically significant pathway for the uptake and accumulation of vitamin C by cells, and suggest a mechanism for the accumulation of ascorbic acid against a concentration gradient.
C1 COLUMBIA UNIV COLL PHYS & SURG,DEPT PHYSIOL & CELLULAR BIOPHYS,NEW YORK,NY 10032.
   COLUMBIA UNIV COLL PHYS & SURG,DEPT OPHTHALMOL,NEW YORK,NY 10032.
C3 Columbia University; Columbia University
RP VERA, JC (corresponding author), MEM SLOAN KETTERING CANC CTR,PROGRAM MOLEC PHARMACOL & THERAPEUT,1275 YORK AVE,NEW YORK,NY 10021, USA.
NR 31
TC 447
Z9 466
U1 0
U2 17
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 79
EP 82
DI 10.1038/364079a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800063
PM 8316303
DA 2026-03-10
ER

PT J
AU YAGI, T
   AIZAWA, S
   TOKUNAGA, T
   SHIGETANI, Y
   TAKEDA, N
   IKAWA, Y
AF YAGI, T
   AIZAWA, S
   TOKUNAGA, T
   SHIGETANI, Y
   TAKEDA, N
   IKAWA, Y
TI A ROLE FOR FYN TYROSINE KINASE IN THE SUCKLING BEHAVIOR OF NEONATAL MICE
SO NATURE
LA English
DT Article
ID olfactory-bulb; rat-brain; localization; protein; gene; main
AB NON-RECEPTOR-TYPE tyrosine kinases of the Src family, such as Src, Yes and Fyn, are strongly expressed in the brain and have been suggested to have an important function in the central nervous system1-5. We generated Fyn-deficient mice by inserting the beta-galactosidase gene (lacZ) into the fyn gene. The homozygous Fyn-mutant neonates from homozygous Fyn-deficient parents died because of a suckling problem. Neonates were, however, able to suckle milk normally when die homozygous mother's mammary glands had been activated by suckling of a heterozygous or wild-type pup. In these homozygous pups, the modified glomerular complex of the olfactory bulb, which had been suggested to play a role in perceiving pheromones, was abnormal in shape and reduced in size, and the hippocampal cell-layer was undulated. These results suggest that Fyn may be involved in the initial step of instinctive suckling behaviour in neonates.
C1 INST PHYS & CHEM RES,TSUKUBA LIFE SCI CTR,MOLEC ONCOL LAB,IBARAKI 305,JAPAN.
   TOKYO MED & DENT UNIV,SCH MED,DEPT BIOCHEM,TOKYO 113,JAPAN.
C3 RIKEN; Institute of Science Tokyo; Tokyo Medical & Dental University (TMDU)
NR 16
TC 146
Z9 155
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 23
PY 1993
VL 366
IS 6457
BP 742
EP 745
DI 10.1038/366742a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MN264
UT WOS:A1993MN26400028
PM 8264796
DA 2026-03-10
ER

PT J
AU SAUER, F
   JACKLE, H
AF SAUER, F
   JACKLE, H
TI DIMERIZATION AND THE CONTROL OF TRANSCRIPTION BY KRUPPEL
SO NATURE
LA English
DT Article
ID alcohol-dehydrogenase gene; cultured drosophila cells; activation; protein; repression; binding; product; embryo; stripe; yeast
AB KRUPPEL (KR), a Drosophila zinc finger-type1 transcription factor2-4, can both activate and repress gene expression through interaction with a single DNA-binding site4. The opposite regulatory effects of KR are concentration-dependent, and they require distinct portions of KR such as the N-terminal region for activation and the C-terminal region for repression4.  Here we show that KR is able to form homodimers through sequences located within the C terminus. When these sequences were fused to separated functional parts of the yeast transcription factor GAL4(5), they reconstituted a functional transcriptional activator on dimerization in vivo. Our results suggest that the KR monomer is a transcriptional activator. At higher concentration KR forms a homodimer and becomes a repressor that functions through the same target sequences as the activator.
RP SAUER, F (corresponding author), MAX PLANCK INST BIOPHYS CHEM,MOLEK ENTWICKLUNGSBIOL ABT,POSTFACH 2841,D-37018 GOTTINGEN,GERMANY.
NR 24
TC 100
Z9 111
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 454
EP 457
DI 10.1038/364454a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000058
PM 8332216
DA 2026-03-10
ER

PT J
AU VANOSTADE, X
   VANDENABEELE, P
   EVERAERDT, B
   LOETSCHER, H
   GENTZ, R
   BROCKHAUS, M
   LESSLAUER, W
   TAVERNIER, J
   BROUCKAERT, P
   FIERS, W
AF VANOSTADE, X
   VANDENABEELE, P
   EVERAERDT, B
   LOETSCHER, H
   GENTZ, R
   BROCKHAUS, M
   LESSLAUER, W
   TAVERNIER, J
   BROUCKAERT, P
   FIERS, W
TI HUMAN TNF MUTANTS WITH SELECTIVE ACTIVITY ON THE P55 RECEPTOR
SO NATURE
LA English
DT Article
ID tumor-necrosis-factor; human cell-lines; factor-alpha; mutational analysis; cytolytic activity; recombinant human; induction; invitro; variety; lethal
AB THE remarkable ability of tumour necrosis factor (TNF), especially in combination with interferon, selectively to kill or inhibit malignant cell lines is so far unmatched by any other combination of cytokines1-4. But clinical trials in cancer patients have on the whole been disappointing5-7, and it has been estimated that a TNF dose would be effective only at 5-25 times the maximum tolerated dose  4. High TNF concentrations give a much more pronounced antitumour activity in mice1,8-10, in which murine TNF is about 50-fold more systemically toxic than human TNF11,12.                   . But there is little or no species specificity in cytotoxicity of murine TNF and human TNF on human as well as on murine cell lines13,14. This dual action of TNF may be explained by the existence of two types of receptor for TNF15,16: the smaller, TNF-R55, is present on most cells and particularly on those susceptible to the cytotoxic action of TNF17; the larger, TNF-R75, is also present on many cell types15,16, especially those of myeloid origin, and is strongly expressed on stimulated T and B lymphocytes18. In mice, human TNF binds only to murine TNF-R55 (ref. 15), which can then mediate cytotoxic activity on malignant cells15-17,19. As human TNF does not bind to murine TNF-R75, the latter must be responsible for the much enhanced systemic toxicity of murine TNF. Human TNF can, however, become toxic in mice when a second pathway is activated1,11,20. There is no reciprocal situation in the human system: human and murine TNF bind almost equally well to the two human TNF receptors. Here we describe human TNF mutants that still interact with the human TNF-R55 receptor but which have largely lost their ability to bind to human TNF-R75. Activation of TNF-R55 is sufficient to trigger cytotoxic activity towards transformed cells. One representative human TNF mutant retains its antitumour activity in nude mice carrying tumours derived from human cancers. Under the appropriate conditions, such human TNF mutants are expected to induce less systemic toxicity in man, while still exerting their direct antitumour effect.
C1 F HOFFMANN LA ROCHE & CO LTD,PHARMACEUT RES NEW TECHNOL,CH-4002 BASEL,SWITZERLAND.
   ROCHE RES,B-9000 GHENT,BELGIUM.
C3 Roche Holding
RP VANOSTADE, X (corresponding author), STATE UNIV GHENT,MOLEC BIOL LAB,KL LEDEGANCKSTR 35,B-9000 GHENT,BELGIUM.
NR 28
TC 183
Z9 219
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 266
EP 269
DI 
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400062
PM 8380906
DA 2026-03-10
ER

PT J
AU JOHNSON, DG
   SCHWARZ, JK
   CRESS, WD
   NEVINS, JR
AF JOHNSON, DG
   SCHWARZ, JK
   CRESS, WD
   NEVINS, JR
TI EXPRESSION OF TRANSCRIPTION FACTOR E2F1 INDUCES QUIESCENT CELLS TO ENTER S-PHASE
SO NATURE
LA English
DT Article
ID retinoblastoma gene-product; cellular dna-synthesis; binding protein; adenovirus-e1a prevents; cycle regulation; e1a proteins; domains; rb; identification; suppressor
AB SEVERAL lines of evidence implicate the E2F transcription factor as an important component of cell proliferation control. First, E2F binding sites are found in the promoters of genes responsive to proliferation signals and the level of E2F binding activity increases at a time when many of these genes are activated1-3. Second, the tumour suppressor protein Rb, as well as the related p107 protein, complexes with E2F2-7, resulting in an inhibition of E2F transcriptional activity3,8-12. Third, oncogenic products of the DNA tumour viruses can dissociate these E2F complexes4,13. We provide here direct evidence that E2F is involved in cellular proliferation control. Specifically, we demonstrate that overexpression of the E2F1 complementary DNA14,15 can activate DNA synthesis in cells that would otherwise growth-arrest, with an efficiency that is similar to that achieved by the expression of the adenovirus E1A gene. Moreover, microinjection of the E2F1 cDNA into quiescent cells can induce S-phase entry, whereas two E2F1 mutants, which are unable to transactivate the DHFR and TK promoters, are unable to induce S phase. We conclude that the E2F transcription factor plays an important role in progression into S phase and that this probably coincides with its capacity to stimulate transcription.
RP JOHNSON, DG (corresponding author), DUKE UNIV,MED CTR,HOWARD HUGHES MED INST,GENET SECT,POB 3054,DURHAM,NC 27710, USA.
NR 31
TC 782
Z9 893
U1 1
U2 23
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 349
EP 352
DI 10.1038/365349a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600055
PM 8377827
DA 2026-03-10
ER

PT J
AU STAVELEYSMITH, L
   BRIGGS, DS
   ROWE, ACH
   MANCHESTER, RN
   REYNOLDS, JE
   TZIOUMIS, AK
   KESTEVEN, MJ
AF STAVELEYSMITH, L
   BRIGGS, DS
   ROWE, ACH
   MANCHESTER, RN
   REYNOLDS, JE
   TZIOUMIS, AK
   KESTEVEN, MJ
TI STRUCTURE OF THE RADIO REMNANT OF SUPERNOVA-1987A
SO NATURE
LA English
DT Article
ID 1987a; emission
AB SUPERNOVA 1987A in the Large Magellanic Cloud, the closest known supernova for 400 years, offers unprecedented opportunities for the detailed study of the evolution of a supernova at all wavelengths. The radio remnant of SN1987A was detected in July 1990 (ref. 1), since when it has steadily brightened at all radio frequencies2. Its present brightness and size are now sufficient for its structure to be resolved. Here, we present high-resolution images of the remnant at a frequency of 8.8 GHz, which reveal a spherical, shell-like structure with a radius of 0.6 arcsec (4 x 10(17) cm, assuming a distance of 50 kpc) and an additional component that is aligned with the optical ring (of somewhat larger radius) imaged by the Hubble Space Telescope3. We suggest that this alignment arises from an interaction between the expanding shock wave and dense clouds sheared from the ring. The mean expansion velocity of the supernova shock front, as measured from its current radio size, is approximately 30,000 km s-1. Observations made over 600 days suggest, however, that either the remnant is rapidly changing shape or that the expansion velocity is decreasing more rapidly than expected.
C1 NATL RADIO ASTRON OBSERV,SOCORRO,NM 87801.
   UNIV WESTERN AUSTRALIA,NEDLANDS,WA 6009,AUSTRALIA.
C3 National Radio Astronomy Observatory (NRAO); University of Western Australia
RP STAVELEYSMITH, L (corresponding author), CSIRO,AUSTRALIA TELESCOPE NATL FACIL,POB 76,EPPING,NSW 2121,AUSTRALIA.
NR 19
TC 51
Z9 52
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 136
EP 138
DI 10.1038/366136a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600049
DA 2026-03-10
ER

PT J
AU GUNZBURG, WH
   HEINEMANN, F
   WINTERSPERGER, S
   MIETHKE, T
   WAGNER, H
   ERFLE, V
   SALMONS, B
AF GUNZBURG, WH
   HEINEMANN, F
   WINTERSPERGER, S
   MIETHKE, T
   WAGNER, H
   ERFLE, V
   SALMONS, B
TI ENDOGENOUS SUPERANTIGEN EXPRESSION CONTROLLED BY A NOVEL PROMOTER IN THE MMTV LONG TERMINAL REPEAT
SO NATURE
LA English
DT Article
ID mammary-tumor virus; open reading frame; messenger-rna; env gene; t-cells; region; identification; sequences; system; mice
AB ENDOGENOUS superantigens are encoded by the open reading frame contained within the mouse mammary tumour virus long terminal repeat (MMTV LTR). Superantigen expression results in T-cell proliferation and, during early ontogeny, T-cell deletion1,2. Here we identify a novel promoter located upstream of the previously described MMTV promoter. Transcripts from this promoter initiate within the U3 region of the MMTV LTR and splice to the acceptor for endogenous superantigen coding region. The novel U3 promoter is active in B lymphocytes, which are cognate antigen-presenting cells for endogenous superantigen, and is able to direct expression of superantigen in the absence of the previously described MMTV promoter.
C1 TECH UNIV MUNICH,INST MED MICROBIOL & HYG,D-81675 MUNICH,GERMANY.
   LUDWIG MAXIMILIANS UNIV MUNCHEN,INST MOLEC ANIM BREEDING,D-80539 MUNICH,GERMANY.
C3 Technical University of Munich; University of Munich
RP GUNZBURG, WH (corresponding author), GSF RES CTR ENVIRONM & HLTH,INST MOLEC VIROL,D-85758 OBERSCHLEISSHEIM,GERMANY.
NR 26
TC 47
Z9 50
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 154
EP 158
DI 10.1038/364154a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700052
PM 8391646
DA 2026-03-10
ER

PT J
AU GETHER, U
   JOHANSEN, TE
   SNIDER, RM
   LOWE, JA
   NAKANISHI, S
   SCHWARTZ, TW
AF GETHER, U
   JOHANSEN, TE
   SNIDER, RM
   LOWE, JA
   NAKANISHI, S
   SCHWARTZ, TW
TI DIFFERENT BINDING EPITOPES ON THE NK1 RECEPTOR FOR SUBSTANCE-P AND A NONPEPTIDE ANTAGONIST
SO NATURE
LA English
DT Article
ID beta-adrenergic-receptor; beta-2-adrenergic receptors; ligand-binding; specificity; expression; inhibitors; agonist; sites; cdna
AB NON-PEPTIDE ligands for peptide receptors have been discovered in several systems through file screening programs1-6, but the mechanism of action for these candidate drugs is obscure as they do not chemically resemble the native peptides. The compound CP 96345 is a high-affinity, non-peptide antagonist of the substance P (NK1) receptor4,5,7, which is important in pain perception and neurogenic inflammation8-11. Here we identify epitopes on the NK1 receptor responsible for the specific binding of CP 96345 by systematic exchange of corresponding segments between the NK1 receptor and the homologous NK3 (neurokinin B) receptor, which does not bind the non-peptide ligand. Non-conserved residues, in two epitopes around the top of transmembrane segment V and in one epitope at the top of transmembrane segment VI, are essential for the specific action of CP 96345 on the NK1 receptor, but are surprisingly not important for the binding of the natural peptide ligand, substance P. Susceptibility to the non-peptide antagonists can be conveyed to the previously unresponsive NK3 receptor by mutational transfer of this discontinuous epitope from the NK1 receptor.
C1 PFIZER INC, DIV CENT RES, DEPT EXPLORATORY MED CHEM, GROTON, CT 06340 USA.
   KYOTO UNIV, FAC MED, INST IMMUNOL, KYOTO 606, JAPAN.
C3 Pfizer; Pfizer USA; Kyoto University
RP GETHER, U (corresponding author), UNIV COPENHAGEN, DEPT CLIN BIOCHEM, MOLEC ENDOCRINOL LAB, RIGSHOSP 6321, BLEGDAMSVEJ 9, DK-2100 COPENHAGEN, DENMARK.
NR 28
TC 237
Z9 239
U1 0
U2 5
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 345
EP 348
DI 10.1038/362345a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600061
PM 7681152
DA 2026-03-10
ER

PT J
AU SERIZAWA, H
   CONAWAY, JW
   CONAWAY, RC
AF SERIZAWA, H
   CONAWAY, JW
   CONAWAY, RC
TI PHOSPHORYLATION OF C-TERMINAL DOMAIN OF RNA POLYMERASE-II IS NOT REQUIRED IN BASAL TRANSCRIPTION
SO NATURE
LA English
DT Article
ID preinitiation complex; beta-gamma; initiation; purification; promoter; kinase; alpha; form
AB PHOSPHORYLATION of the heptapeptide repeats in the C-terminal domain (CTD) of the largest subunit of RNA polymerase II has been widely proposed as an essential step in transcription initiation1-8 on the basis of findings indicating (1) that the CTDs of RNA polymerase II molecules actively engaged in transcription are highly phosphorylated4,9,10; (2) that polymerase molecules containing non-phosphorylated CTDs preferentially enter the preinitiation complex3,11,12 where they are subsequently phosphorylated3,13; and (3) that essential initiation factors b from yeast14-16, delta from rat17,18, and BTF2(TFIIH) from human cells19-21 have closely associated CTD-kinase activities. Here we take advantage of a highly purified enzyme system which supports both CTD phosphorylation and basal transcription to test this hypothesis directly. Using the isoquinoline sulphonamide derivative H-8, which is a potent inhibitor of CTD kinase, we show that basal transcription occurs in the absence of CTD phosphorylation.
RP SERIZAWA, H (corresponding author), OKLAHOMA MED RES FDN,PROGRAM MOLEC & CELL BIOL,825 NE 13TH ST,OKLAHOMA CITY,OK 73104, USA.
NR 29
TC 161
Z9 175
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 371
EP 374
DI 10.1038/363371a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700060
PM 8497323
DA 2026-03-10
ER

PT J
AU SCHUSTER, SC
   SWANSON, RV
   ALEX, LA
   BOURRET, RB
   SIMON, MI
AF SCHUSTER, SC
   SWANSON, RV
   ALEX, LA
   BOURRET, RB
   SIMON, MI
TI ASSEMBLY AND FUNCTION OF A QUATERNARY SIGNAL-TRANSDUCTION COMPLEX MONITORED BY SURFACE-PLASMON RESONANCE
SO NATURE
LA English
DT Article
ID bacterial chemotaxis; response regulator; protein-phosphorylation; kinase chea; receptor; pathway; system; site
AB WE have used surface plasmon resonance biosensor technology to monitor the assembly and dynamics of a signal transduction complex which controls chemotaxis in Escherichia coli. A quaternary complex formed which consisted of the response regulator CheY, the histidine protein kinase CheA, a coupling protein CheW and a membrane-bound chemoreceptor Tar. Using various experimental conditions and mutant proteins, we have shown that the complex dissociates under conditions that favour phosphorylation of CheY. Direct physical analysis of interactions among proteins in this signal transduction pathway provides evidence for a previously unrecognized binding interaction between the kinase and its substrate. This interaction may be important for enhancing substrate specificity and preventing 'crosstalk' with other systems. The approach is generally applicable to furthering our understanding of how signalling complexes transduce intracellular messages.
RP SCHUSTER, SC (corresponding author), CALTECH,DIV BIOL,PASADENA,CA 91125, USA.
NR 25
TC 228
Z9 248
U1 0
U2 29
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 343
EP 347
DI 10.1038/365343a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600053
PM 8377825
DA 2026-03-10
ER

PT J
AU CHI, X
   WOLFENDALE, AW
AF CHI, X
   WOLFENDALE, AW
TI THE STRENGTH OF GALACTIC MAGNETIC-FIELDS
SO NATURE
LA English
DT Article
ID origin
AB THE magnitudes of galactic magnetic fields are usually estimated from measurements of the radio synchroton emission arising from acceleration of cosmic-ray electrons in the magnetic field. To interpret the emission spectrum, it is usually assumed that the energy density in the magnetic field is equal to that in the cosmic-ray protons (which are assumed to outnumber the electrons by 100:1, as they do in our Galaxy). There is, however, no compelling justification for this assumption of energy equipartition. Here we use measurements by the Compton Gamma Ray Observatory1,2 of the gamma-ray flux from the Magellanic clouds together with radio continuum data to estimate the strength of the magnetic fields in these galaxies without having to invoke energy equipartition. We find that the assumption of energy equipartition is not valid in these irregular galaxies, and that the validity cannot be restored by changing the electron/proton ratio. Supporting evidence for our conclusion comes from radio and X-ray observations (M. G. Watson, personal communication) of the starburst galaxy M82. Our results imply that these galactic fields are too large to have been generated by dynamo action alone, and we suggest that recent star formation might instead provide the generating mechanism.
RP CHI, X (corresponding author), UNIV DURHAM,DEPT PHYS,SOUTH RD,DURHAM DH1 3LE,ENGLAND.
NR 18
TC 32
Z9 35
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 610
EP 611
DI 10.1038/362610a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800038
DA 2026-03-10
ER

PT J
AU GIRLING, R
   PARTRIDGE, JF
   BANDARA, LR
   BURDEN, N
   TOTTY, NF
   HSUAN, JJ
   LATHANGUE, NB
AF GIRLING, R
   PARTRIDGE, JF
   BANDARA, LR
   BURDEN, N
   TOTTY, NF
   HSUAN, JJ
   LATHANGUE, NB
TI A NEW COMPONENT OF THE TRANSCRIPTION FACTOR-DRTF1/E2F
SO NATURE
LA English
DT Article
ID retinoblastoma gene-product; carcinoma stem-cells; t-antigen; cyclin-a; protein; differentiation; binding; transactivation; adenovirus-e1a; regions
AB TRANSCRIPTION factor DRTF1/E2F coordinates events in the cell cycle with transcription by its cyclical interactions with important regulators of cellular proliferation like the retinoblastoma tumour-suppressor gene product (Rb) and the Rb-related protein, p107 (refs 1-8). DRTF1/E2F binding sites occur in the control regions of genes involved in proliferation9,10, and both Rb and p107 repress the capacity of DRTF1/E2F to activate transcription (refs 11, 12; M. Zamanian and N.B.L.T., manuscript submitted). Mutant Rb proteins isolated from tumour cells are unable to bind DRTF1/E2F (refs 11-13), and certain viral oncoproteins, such as adenovirus E1A, sequester Rb and p107 in order to free active DRTF1/E2F (refs 5, 11, 12, 14, 15). Here we report the isolation of a complementary DNA encoding DRTF1-polypeptide-1 (DP-1), a major sequence-specific binding protein that is present in DRTF1/E2F, including Rb- and p107-associated DRTF1/E2F. The DNA-binding domain of DP-1 contains a region that resembles that of E2F-1 (refs 16, 17), and recognizes the same sequence. DRTF1/E2F thus appears to contain at least two sequence-specific DNA-binding proteins.
C1 MRC,NATL INST MED RES,EUKARYOT MOLEC GENET LAB,RIDGEWAY,MILL HILL,LONDON NW7 1AA,ENGLAND.
   MIDDLESEX HOSP,LUDWIG INST CANC RES,LONDON W1P 8BT,ENGLAND.
C3 MRC National Institute for Medical Research; Ludwig Institute for Cancer Research; University of London; University College London
NR 33
TC 253
Z9 284
U1 1
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 83
EP 87
DI 10.1038/362083a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600067
PM 8446173
DA 2026-03-10
ER

PT J
AU PANTALEO, G
   GRAZIOSI, C
   DEMAREST, JF
   BUTINI, L
   MONTRONI, M
   FOX, CH
   ORENSTEIN, JM
   KOTLER, DP
   FAUCI, AS
AF PANTALEO, G
   GRAZIOSI, C
   DEMAREST, JF
   BUTINI, L
   MONTRONI, M
   FOX, CH
   ORENSTEIN, JM
   KOTLER, DP
   FAUCI, AS
TI HIV-INFECTION IS ACTIVE AND PROGRESSIVE IN LYMPHOID-TISSUE DURING THE CLINICALLY LATENT STAGE OF DISEASE
SO NATURE
LA English
DT Article
ID human-immunodeficiency-virus; cells; aids; lymphadenopathy; amplification; reservoirs; expression; nodes; rna
AB PRIMARY infection with the human immunodeficiency virus (HIV) is generally followed by a burst of viraemia with or without clinical symptoms1-3. This in turn is followed by a prolonged period of clinical latency. During this period there is little, if any, detectable viraemia, the numbers of infected cells in the blood are very low, and it is extremely difficult to demonstrate virus expression in these cells4. We have analysed viral burden and levels of virus replication simultaneously in the blood and lymphoid organs of the same individuals at various stages of HIV disease. Here we report that in early-stage disease there is a dichotomy between the levels of viral burden and virus replication in peripheral blood versus lymphoid organs. HIV disease is active in the lymphoid tissue throughout the period of clinical latency, even at times when minimal viral activity is demonstrated in blood.
C1 UNIV ANCONA,DEPT INTERNAL MED,I-60020 ANCONA,ITALY.
   YALE UNIV,SCH MED,DEPT NEUROPATHOL,NEW HAVEN,CT 06510.
   GEORGE WASHINGTON UNIV,DEPT PATHOL,WASHINGTON,DC 20037.
   ST LUKES ROOSEVELT HOSP,NEW YORK,NY 10025.
C3 Marche Polytechnic University; Yale University; George Washington University; Mount Sinai West; Mount Sinai Morningside
RP PANTALEO, G (corresponding author), NIAID,IMMUNOREGULAT LAB,BETHESDA,MD 20892, USA.
NR 23
TC 1701
Z9 1867
U1 0
U2 70
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 355
EP 358
DI 10.1038/362355a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600065
PM 8455722
DA 2026-03-10
ER

PT J
AU SOUSA, R
   CHUNG, YJ
   ROSE, JP
   WANG, BC
AF SOUSA, R
   CHUNG, YJ
   ROSE, JP
   WANG, BC
TI CRYSTAL-STRUCTURE OF BACTERIOPHAGE-T7 RNA-POLYMERASE AT 3.3-ANGSTROM RESOLUTION
SO NATURE
LA English
DT Article
ID ribonucleic-acid polymerase; escherichia-coli; 3-dimensional structure; nucleotide-sequence; binding-site; transcription; identification; dna; initiation; promoter
AB The crystal structure of T7 RNA polymerase reveals a molecule organized around a cleft that can accommodate a double-stranded DNA template. A portion (approximately 45%) of the molecule displays extensive structural homology to the polymerase domain of Klenow fragment and more limited homology to the human immunodeficiency virus HIV-1 reverse transcriptase. A comparison of the structures and sequences of these polymerases identifies structural elements that may be responsible for discriminating between ribonucleotide and deoxyribonucleotide substrates, and RNA and DNA templates. The relative locations of the catalytic site and a specific promoter recognition residue allow the orientation of the polymerase on the template to be defined.
C1 UNIV PITTSBURGH,DEPT BIOL SCI,PITTSBURGH,PA 15260.
   UNIV PITTSBURGH,DEPT CRYSTALLOG,PITTSBURGH,PA 15260.
C3 Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh; Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh
NR 53
TC 366
Z9 421
U1 0
U2 19
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 593
EP 599
DI 10.1038/364593a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100042
PM 7688864
DA 2026-03-10
ER

PT J
AU HIPPELEIN, H
   MEISENHEIMER, K
AF HIPPELEIN, H
   MEISENHEIMER, K
TI IMAGING OF A LYMAN-ALPHA ABSORPTION CLOUD IN FRONT OF THE RADIO GALAXY 4C41.17
SO NATURE
LA English
DT Article
ID absorbing clouds; redshift; forest
AB THE quasar absorption lines known as the Lyman-alpha forest reveal the presence of a population of extragalactic objects, thought to be clouds of gas or gas-rich protogalaxies. The gas seems to be highly ionized (N(HI)/N(HII)) almost-equal-to 10(-4)), with column densities (N(HI)) ranging from 10(12) to 10(18) cm-2 and Doppler parameters of 15-40 km s-1 (refs 1-3). Different types of measurement have yielded strongly discrepant numbers for the typical diameter, from several tens of kiloparsecs4,5 to only approximately 5 parsecs6,7.  Nothing is known about the clouds' shape (spheres or sheets), which could provide another clue to their origin8. The observation of huge, luminous Ly-alpha haloes around some high-redshift radio galaxies9-11 provides a new way of obtaining information about Lyman cloud size and shape: the large sizes (many tens of kiloparsecs) and broad emission-line profiles of these haloes make them ideal light screens against which absorbing clouds at similar redshift might be seen as dark shadows. We report here the possible detection of such an absorbing cloud in front of the radio galaxy 4C41.17; in the simplest interpretation, the cloud has an elongated shape, and dimensions of approximately 40 x 10 kiloparsecs.
RP HIPPELEIN, H (corresponding author), MAX PLANCK INST ASTRON,KONIGSTUHL 17,W-6900 HEIDELBERG 1,GERMANY.
NR 15
TC 23
Z9 23
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 224
EP 226
DI 10.1038/362224a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600047
DA 2026-03-10
ER

PT J
AU VALET, JP
   MEYNADIER, L
AF VALET, JP
   MEYNADIER, L
TI GEOMAGNETIC-FIELD INTENSITY AND REVERSALS DURING THE PAST 4 MILLION YEARS
SO NATURE
LA English
DT Article
ID polarity reversals; lava flows; sediments; paleointensity; core; brunhes; pacific
AB A long and continuous record of the geomagnetic field intensity shows that intensity variations are dominated by two modes. Major episodes of field regeneration prevail on timescales of a few thousand years immediately after most reversals, whereas stable polarity states are characterized by a slow (approximately 0.5 Myr) relaxation process. Reversals can be seen as the consequence of a progressive degradation of the dipole field.
RP VALET, JP (corresponding author), INST PHYS GLOBE, 4 PL JUSSIEU, F-75252 PARIS 05, FRANCE.
NR 39
TC 345
Z9 357
U1 0
U2 24
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 234
EP 238
DI 10.1038/366234a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500053
DA 2026-03-10
ER

PT J
AU ROBERTS, SGE
   HA, I
   MALDONADO, E
   REINBERG, D
   GREEN, MR
AF ROBERTS, SGE
   HA, I
   MALDONADO, E
   REINBERG, D
   GREEN, MR
TI INTERACTION BETWEEN AN ACIDIC ACTIVATOR AND TRANSCRIPTION FACTOR-TFIIB IS REQUIRED FOR TRANSCRIPTIONAL ACTIVATION
SO NATURE
LA English
DT Article
ID binding; mechanism; mediator; invitro; domain; vp16
AB HOW eukaryotic promoter-specific activator proteins (activators) stimulate transcription is a central question. We have previously shown that an acidic activator can directly interact with the general transcription factor TFIIB and increase its stable assembly into a preinitiation complex1,2. We have proposed that this increase in TFIIB assembly is at least part of the mechanism by which an acidic activator functions1,2. A prediction of this hypothesis is that a TFIIB mutant unable to interact with an acidic activator could not support activated transcription, and here we present experiments that verify this prediction. In conjunction with previous studies, our results argue that interaction between an acidic activator and TFIIB is necessary for transcriptional activation.
C1 UNIV MED & DENT NEW JERSEY,ROBERT WOOD JOHNSON MED SCH,DEPT BIOCHEM,PISCATAWAY,NJ 08854.
C3 Rutgers University System; Rutgers University New Brunswick; Rutgers University Biomedical & Health Sciences
RP ROBERTS, SGE (corresponding author), UNIV MASSACHUSETTS,MED CTR,PROGRAM MOLEC MED,373 PLANTAT ST,WORCESTER,MA 01605, USA.
NR 18
TC 209
Z9 218
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 741
EP 744
DI 10.1038/363741a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900062
PM 8515819
DA 2026-03-10
ER

PT J
AU CATARSI, S
   DRAPEAU, P
AF CATARSI, S
   DRAPEAU, P
TI TYROSINE KINASE-DEPENDENT SELECTION OF TRANSMITTER RESPONSES INDUCED BY NEURONAL CONTACT
SO NATURE
LA English
DT Article
ID identified leech neuron; acetylcholine-receptor; culture; reinnervation; connections; serotonin
AB TRANSMITTER receptors are localized to discrete cellular sites1 such that only those responses appropriate for a particular pattern of inputs are activated2-4. How neurons select between synaptic and extrasynaptic responses during development is not understood. We have investigated how contact during synapse formation between identified leech neurons5-7 selectively suppresses the modulation of extrasynaptic channels by protein kinase C8-10. A microelectrode with an isolated membrane patch containing channels from an uninnervated target neuron was 'crammed'11 into a similar cell contacted by a presynaptic partner. We report here that within a few minutes, the crammed channels were rendered insensitive to activation of protein kinase C, demonstrating the action of a cytoplasmic signal. Treatment of the neurons with selective inhibitors of tyrosine kinases12, which are signalling molecules during normal and oncogenic cellular differentiation13,14, prevented the loss of channel modulation. Thus, tyrosine kinases mediate early functional changes during specific synapse formation that are induced by neuronal contact.
C1 MONTREAL GEN HOSP,RES INST,MONTREAL H3G 1A4,QUEBEC,CANADA.
C3 McGill University
RP CATARSI, S (corresponding author), MCGILL UNIV,CTR RES NEUROSCI,1650 CEDAR AVE,MONTREAL H3G 1A4,PQ,CANADA.
NR 29
TC 35
Z9 37
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 353
EP 355
DI 10.1038/363353a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700054
PM 7684513
DA 2026-03-10
ER

PT J
AU BRISKIN, MJ
   MCEVOY, LM
   BUTCHER, EC
AF BRISKIN, MJ
   MCEVOY, LM
   BUTCHER, EC
TI MADCAM-1 HAS HOMOLOGY TO IMMUNOGLOBULIN AND MUCIN-LIKE ADHESION RECEPTORS AND TO IGA1
SO NATURE
LA English
DT Article
ID vascular addressin; endothelial-cells; lymph-node; binding; gene; lymphocytes; superfamily; recognition; antibody; molecule
AB TISSUE-SPECIFIC homing of lymphocytes is regulated by interactions with the endothelium of specialized venules, such as the high endothelial venules (HEV) in lymph nodes and mucosal lymphoid tissues1-3. The mucosal vascular addressin, a 58-66K glycoprotein adhesion receptor for lymphocytes, is selectively expressed on HEV of mucosal lymphoid organ and on lamina propria venules and helps direct lymphocyte traffic to these mucosal tissues4,5. We now report the isolation of a complementary DNA that, on transfection into COS cells, encodes immunoreactive addressin that specifically binds the mucosal HEV-binding T-cell lymphoma TK1. The predicted amino-acid sequence defines the mucosal addressin as a novel immunoglobulin family member, MAdCAM-1, with two amino-terminal domains that display strong homology to previously described vascular adhesion receptors for leukocytes, ICAM-1 (ref. 6) and VCAM-1 (ref. 7). The membrane proximal domain is homologous to the third domain (Calpha2) of another mucosa-associated immunoglobulin family member, IgA1 (refs 8, 9). In addition to the immunoglobulin domains, there is a serine/threonine-rich region which may serve as a backbone to present carbohydrate ligands to lymphocytes. MAdCAM-1 is thus a complex multidomain receptor displaying several structural motifs that may participate in lymphocyte homing interactions.
C1 STANFORD UNIV, CTR DIGEST DIS, STANFORD, CA 94305 USA.
   VET ADM MED CTR, CTR MOLEC BIOL & MED, PALO ALTO, CA 94304 USA.
C3 Stanford University; US Department of Veterans Affairs; Veterans Health Administration (VHA)
RP BRISKIN, MJ (corresponding author), STANFORD UNIV, DEPT PATHOL, IMMUNOL & VASC BIOL LAB, STANFORD, CA 94305 USA.
NR 28
TC 372
Z9 415
U1 0
U2 6
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 461
EP 464
DI 10.1038/363461a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800062
PM 8502297
DA 2026-03-10
ER

PT J
AU REGENSBURGTUINK, AJG
   HOOYKAAS, PJJ
AF REGENSBURGTUINK, AJG
   HOOYKAAS, PJJ
TI TRANSGENIC N-GLAUCA PLANTS EXPRESSING BACTERIAL VIRULENCE GENE VIRF ARE CONVERTED INTO HOSTS FOR NOPALINE STRAINS OF A-TUMEFACIENS
SO NATURE
LA English
DT Article
ID octopine ti-plasmid; agrobacterium-tumefaciens; transformation; region; mutants; vectors; proteins
AB TUMOURS are induced by Agrobacterium tumefaciens on a variety of plants1-3. The virulence determinants of A. tumefaciens reside on a large tumour-inducing (Ti) plasmid. This plasmid carries two regions essential for tumour induction, namely the T region and the Vir region. During infection the T region is transferred to the plant cell, where it becomes stably integrated in one of the host chromosomes as T-DNA. Expression of T-DNA leads to the production of the plant hormones auxin and cytokinin, as well as to the synthesis of specific amino-acid derivatives termed opines. Agrobacterium strains are classified according to the types of opines produced by the tumours they induce. The Vir region contains genes that are expressed in the bacterium and are required for T-DNA transfer to plant cells, and several other genes that affect the efficiency of transfer and the host range. Vir regions from different Ti plasmids may vary slightly in the genes they contain: for instance, the virF gene, which is present in the Vir-region of octopine Ti plasmids, is absent from nopaline Ti plasmids4,5. Mutation of the virF gene leads to a weakened virulence of octopine strains on tomato6 and Nicotiana glauca (shrub tobacco)4. Nopaline strains are strongly attenuated in N. glauca compared with octopine strains because of the absence of the virF virulence gene from the Ti plasmid in nopaline strains4. The virF gene product way be transferred to and be active in plant cells. Here we isolate transgenic N. glanca plants in which the virF coding sequence is expressed using the cauliflower mosaic virus 35S promoter. The presence of the VirF protein converts the non-host N. glanca into a host for tumour formation by A. tumefaciens nopaline strains and octopine virF mutants. Our results indicate that certain virulence gene products such as the VirF protein may be transferred to plant cells during tumour induction, where they function as mediators of T-DNA transfer.
C1 INST MOLEC PLANT SCI,CLUSIUS LAB,WASSENAARSEWEG 64,2333 AL LEIDEN,NETHERLANDS.
NR 25
TC 69
Z9 81
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 69
EP 71
DI 10.1038/363069a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200060
PM 8479538
DA 2026-03-10
ER

PT J
AU ZHAO, JJG
   PICK, L
AF ZHAO, JJG
   PICK, L
TI GENERATING LOSS-OF-FUNCTION PHENOTYPES OF THE FUSHI-TARAZU GENE WITH A TARGETED RIBOZYME IN DROSOPHILA
SO NATURE
LA English
DT Article
ID segmentation gene; self-cleavage; messenger-rna; melanogaster; embryogenesis; neurogenesis; expression; reduction; sequence; enzymes
AB THE ability to isolate gene sequences and analyse their expression patterns has generated demand for mutations created to assess their biological functions. In Drosophila melanogaster this can be achieved by traditional mutagenesis, but this is time-consuming, labour-intensive and not always successful. Moreover, the functions of genes that are expressed several times during development are often obscured in the later stages because of disruptions caused by the absence of early gene function. Here we propose a new strategy to create conditional knock-out mutations using a targeted heat-inducible ribozyme. Ribozymes are catalytic RNA molecules that specifically cleave RNAs1-11 and are potentially useful for studying gene function during animal development because the expression of critical regulatory genes is usually low and their function is often dosage-dependent. The ribozyme can be delivered to a specific region or at a particular developmental stage using a region-specific or inducible promoter. The Drosophila fushi tarazu (ftz) gene is a good candidate for testing this approach12-17. We generated transgenic flies carrying a ribozyme against the ftz gene. The two developmental phases of ftz function can be distinguished by timed induction of the ribozyme. Activation of the ribozyme in the blastoderm disrupts the ftz seven-stripe pattern and produces ftz-like pair-rule defects in larvae. The involvement of ftz in neurogenesis was verified by activation of the ribozyme during the early phase of formation of the central nervous system.
C1 CUNY MT SINAI SCH MED,BROOKDALE CTR MOLEC BIOL,NEW YORK,NY 10029.
C3 Icahn School of Medicine at Mount Sinai; City University of New York (CUNY) System
NR 26
TC 79
Z9 94
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 448
EP 451
DI 10.1038/365448a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300058
PM 8413588
DA 2026-03-10
ER

PT J
AU VANDAL, GM
   FITZGERALD, WF
   BOUTRON, CF
   CANDELONE, JP
AF VANDAL, GM
   FITZGERALD, WF
   BOUTRON, CF
   CANDELONE, JP
TI VARIATIONS IN MERCURY DEPOSITION TO ANTARCTICA OVER THE PAST 34,000 YEARS
SO NATURE
LA English
DT Article
ID greenland ice sheet; equatorial pacific-ocean; trace-metals; atmosphere; sulfur; air
AB POLAR ice contains a valuable record of past atmospheric mercury deposition, which can provide information about both the natural biogeochemical cycling of this toxic trace metal and the impact of recent anthropogenic emissions. But existing studies of mercury in polar ice and snow cores1-5 suffer from sample contamination and inadequate analytical procedures. Here we report measurements of mercury concentrations spanning the past 34,000 years from the Dome C ice core, Antarctica, using the stringent trace-metal clean protocols developed by Patterson and co-workers6. Although this record does not extend into the industrial period, it provides an important baseline for future attempts to identify anthropogenic mercury in Antarctic ice and snow. We find that mercury concentrations were strikingly elevated during the last glacial maximum (18,000 years ago), when oceanic productivity may have been higher than it is today7. As oceanic mercury emission is correlated with productivity8,9, we suggest that this was the principal pre-industrial source of mercury to Antarctica; mercury concentrations in Antarctic ice might therefore serve as a palaeoproductivity indicator for the more distant past.
C1 CNRS,GLACIOL & GEOPHYS ENVIRONNEMENT LAB,F-38402 ST MARTIN DHERES,FRANCE.
   UNIV JOSEPH FOURIER,UFR MECAN,F-38041 GRENOBLE,FRANCE.
C3 Centre National de la Recherche Scientifique (CNRS); Communaute Universite Grenoble Alpes; Universite Grenoble Alpes (UGA)
RP VANDAL, GM (corresponding author), UNIV CONNECTICUT,DEPT MARINE SCI,AVERY POINT,GROTON,CT 06340, USA.
NR 30
TC 136
Z9 154
U1 3
U2 55
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 621
EP 623
DI 10.1038/362621a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800043
DA 2026-03-10
ER

PT J
AU GERMAIN, RN
   RINKER, AG
AF GERMAIN, RN
   RINKER, AG
TI PEPTIDE BINDING INHIBITS PROTEIN AGGREGATION OF INVARIANT-CHAIN FREE CLASS-II DIMERS AND PROMOTES SURFACE EXPRESSION OF OCCUPIED MOLECULES
SO NATURE
LA English
DT Article
ID hla-dr molecules; histocompatibility antigens; intracellular-transport; monoclonal-antibody; cell line; ia; association; recognition; gene; h-2
AB EFFICIENT egress of major histocompatibility complex (MHC) class I molecules from the endoplasmic reticulum (ER) depends on peptide binding1-7. For MHC class II molecules, invariant chain (Ii) promotes ER exit of newly assembled, peptide-free dimers8-14. This raises the question of whether a mechanism exists elsewhere in the cell that dictates selective expression of peptide-associated class II molecules. We report here that dissociation of MHC class II-Ii complexes at low pH and physiological temperature leads to inclusion of empty class II in protein aggregates, and that this aggregation is specifically prevented by peptide binding. Combined with data showing that antigen exposure increases cell surface class II expression on living cells by a post-translational mechanism12, these results provide evidence for peptide-dependent intracellular editing of class II dimers, which limits surface expression of empty molecules unsuitable for antigen-specific T-cell activation.
RP GERMAIN, RN (corresponding author), NIAID,IMMUNOL LAB,LYMPHOCYTE BIOL SECT,BETHESDA,MD 20892, USA.
NR 37
TC 162
Z9 171
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 725
EP 728
DI 10.1038/363725a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900057
PM 8515815
DA 2026-03-10
ER

PT J
AU HALL, K
   COLE, DG
   YEH, Y
   SCHOLEY, JM
   BASKIN, RJ
AF HALL, K
   COLE, DG
   YEH, Y
   SCHOLEY, JM
   BASKIN, RJ
TI FORCE-VELOCITY RELATIONSHIPS IN KINESIN-DRIVEN MOTILITY
SO NATURE
LA English
DT Article
ID centrifuge microscope; movement; molecules; invitro
AB KINESIN is a microtubule-based motor protein that uses energy released from Mg-ATP hydrolysis to generate force for the movement of intracellular membranes towards the fast-growing (plus) ends of microtubule tracks in cells1. Kinesin-driven microtubule movement can be visualized and quantified using light microscope motility assays2-5 but our understanding of how kinesin generates force and motion is incomplete6. Here we report the use of a centrifuge microscope7,8 to obtain force-velocity curves for kinesin-driven motility and to estimate that the maximal isometric force generated per kinesin is 0.12+/-0.03 pN per molecule.
C1 UNIV CALIF DAVIS, MOLEC & CELLULAR BIOL SECT, BIOPHYS GRAD GRP, DAVIS, CA 95616 USA.
   UNIV CALIF DAVIS, DEPT APPL SCI, DAVIS, CA 95616 USA.
C3 University of California System; University of California Davis; University of California System; University of California Davis
NR 18
TC 24
Z9 26
U1 0
U2 4
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 457
EP 459
DI 10.1038/364457a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000059
PM 8332217
DA 2026-03-10
ER

PT J
AU RUOFF, RS
   MALHOTRA, R
   HUESTIS, DL
   TSE, DS
   LORENTS, DC
AF RUOFF, RS
   MALHOTRA, R
   HUESTIS, DL
   TSE, DS
   LORENTS, DC
TI ANOMALOUS SOLUBILITY BEHAVIOR OF C60
SO NATURE
LA English
DT Article
AB SOLUBILITIES of solids in liquids exhibit a temperature dependence that is correlated with the energetics of dissolution. For organic solutes in organic solvents the common experience is that solubility increases on warming (that is, dissolution is normally endothermic), forming the basis for purification by crystallization by slow cooling of hot solutions1. Interactions between inorganic compounds and water are often more energetic, and may lead to complicated temperature-dependent solubilities, often associated with the formation of hydrated solid phases2. We have investigated the temperature-dependent solubility of C60 in hexane, toluene and CS2. We observe a solubility maximum near room temperature (around 280 K) for all three solvents. Although the solubility of C60 in these three solvents differs by several orders of magnitude, the temperature dependence of the relative solubilities is much the same in each case. We conclude that dissolution is endothermic below room temperature and exothermic above. We interpret this change as being due to a phase change in solid C60, presumably the phase change observed previously in the absence of a solvent3-5, modified by solvent wetting. A solubility maximum (or minimum) for organic compounds in non-electrolytes is highly unusual, and may be unprecedented. The effect may have consequences for solvent-extraction techniques of fullerene purification.
RP RUOFF, RS (corresponding author), SRI INT,MOLEC PHYS LAB,333 RAVENSWOOD AVE,MENLO PK,CA 94025, USA.
NR 9
TC 206
Z9 221
U1 0
U2 59
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 140
EP 141
DI 10.1038/362140a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800053
DA 2026-03-10
ER

PT J
AU KERR, LD
   RANSONE, LJ
   WAMSLEY, P
   SCHMITT, MJ
   BOYER, TG
   ZHOU, Q
   BERK, AJ
   VERMA, IM
AF KERR, LD
   RANSONE, LJ
   WAMSLEY, P
   SCHMITT, MJ
   BOYER, TG
   ZHOU, Q
   BERK, AJ
   VERMA, IM
TI ASSOCIATION BETWEEN PROTO-ONCOPROTEIN REL AND TATA-BINDING PROTEIN MEDIATES TRANSCRIPTIONAL ACTIVATION BY NF-KAPPA-B
SO NATURE
LA English
DT Article
ID rna polymerase-ii; dna-binding; c-rel; basic repeat; p65 subunit; gene; box; domain; yeast; invitro
AB The c-Rel protein is able to associate in vitro and in vivo with the TATA-binding protein (TBP) of the TFIID complex. Coexpression of TBP with c-Rel augments transactivation from the kappaB site in Drosophila Schneider cells. DNA-binding mutants of TBP not only fall to cooperate, but they repress transactivation by c-Rel. There may be a direct communication between kappaB enhancer binding proteins and basal transcription factors which leads to enhanced transcription.
C1 SALK INST BIOL STUDIES,MOLEC BIOL & VIROL LAB,SAN DIEGO,CA 92138.
   UNIV CALIF LOS ANGELES,INST MOLEC BIOL,DEPT MICROBIOL & MOLEC GENET,LOS ANGELES,CA 90024.
C3 Salk Institute; University of California System; University of California Los Angeles
NR 50
TC 155
Z9 161
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 412
EP 419
DI 10.1038/365412a0
PG 8
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300047
PM 8413585
DA 2026-03-10
ER

PT J
AU WANG, MM
   REED, RR
AF WANG, MM
   REED, RR
TI MOLECULAR-CLONING OF THE OLFACTORY NEURONAL TRANSCRIPTION FACTOR OLF-1 BY GENETIC SELECTION IN YEAST
SO NATURE
LA English
DT Article
ID dna-binding; signal transduction; myc homology; protein; expression; enhancer; system; myod; site; identification
AB A novel genetic selection in yeast has been used to isolate a complementary DNA for the transcriptional activator, Olf-1, which binds to the regulatory sequences of several olfactory-specific genes. The Olf-1 protein, expressed exclusively in the olfactory receptor neurons and their precursors, contains a new helix-loop-helix motif and functions as an apparent homodimer. Olf-1 may be the first member of a family of related proteins that may direct cellular differentiation in a variety of neuronal tissues.
RP WANG, MM (corresponding author), JOHNS HOPKINS UNIV,SCH MED,DEPT MOLEC BIOL & GENET,HOWARD HUGHES MED INST,725 N WOLFE ST,BALTIMORE,MD 21205, USA.
NR 39
TC 377
Z9 444
U1 0
U2 43
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 121
EP 126
DI 10.1038/364121a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700040
PM 8321284
DA 2026-03-10
ER

PT J
AU DAVEY, RJ
   MAGINN, SJ
   ANDREWS, SJ
   BUCKLEY, AM
   COTTIER, D
   DEMPSEY, P
   ROUT, JE
   STANLEY, DR
   TAYLOR, A
AF DAVEY, RJ
   MAGINN, SJ
   ANDREWS, SJ
   BUCKLEY, AM
   COTTIER, D
   DEMPSEY, P
   ROUT, JE
   STANLEY, DR
   TAYLOR, A
TI STABILIZATION OF A METASTABLE CRYSTALLINE PHASE BY TWINNING
SO NATURE
LA English
DT Article
ID polymorphism; transformations; acid
AB POLYMORPHISM of crystal structures-alternative crystal structures resulting from variations in ionic and molecular packing1 and conformation2-is important in a number of fields in solid-state chemistry, including biomineralization3 (in the mineral phases of calcium carbonate3, for example), polymer science (polypropylene4, for example), explosives (ammonium nitrate, lead azide5), nonlinear optical materials6, ceramics and catalysis (zeolites and metal oxides7).  In the pharmaceutical and fine-chemicals industries, polymorphism is central to both production process design and product activity8.  Here we show that crystal twinning can stabilize a crystal polymorph that is otherwise not the most stable form. We use electron microscopy, X-ray diffraction and Raman spectroscopy to show that the apparently indefinite persistence of a metastable polymorph of terephthalic acid can be explained on this basis.  If twinning can be engineered, it may therefore provide a means for stabilizing crystal phases with useful physical properties.
C1 ZENECA PLC,DEPT R&T,RUNCORN WA7 4QD,CHESHIRE,ENGLAND.
   ICI PLC,CHEM & POLYMERS,RUNCORN WA7 4QD,CHESHIRE,ENGLAND.
NR 21
TC 34
Z9 35
U1 0
U2 36
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 248
EP 250
DI 10.1038/366248a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500057
DA 2026-03-10
ER

PT J
AU ANDERSON, G
   JENKINSON, EJ
   MOORE, NC
   OWEN, JJT
AF ANDERSON, G
   JENKINSON, EJ
   MOORE, NC
   OWEN, JJT
TI MHC CLASS-II-POSITIVE EPITHELIUM AND MESENCHYME CELLS ARE BOTH REQUIRED FOR T-CELL DEVELOPMENT IN THE THYMUS
SO NATURE
LA English
DT Article
ID lymphocyte-t; differentiation; mice
AB T LYMPHOCYTES are produced in the thymus from precursors originating in the haemopoietic tissues. On entering the thymus, they undergo a programme of proliferation, T-cell receptor (TCR) gene rearrangement, differentiation and repertoire selection1. Although the thymus provides a unique environment for these events, the role of the thymic stroma in regulating specific developmental stages is not well understood2. We therefore devised an in vitro system to study the role of individual thymic stromal components in T-cell development. We report here that the development of TCR-CD4-CD8- T-cell precursors into TCR+ cells expressing CD4 and/or CD8 requires the presence of both major histocompatibility complex class II+ epithelial cells and fetal mesenchyme. The requirement for mesenchymal support can be mapped to the initial stages of intrathymic development because the later stages of maturation, from double-positive CD4+CD8+ thymocytes into single-positive CD4+ or CD8+ cells, can be supported by epithelial cells alone. We also show that the requirement for mesenchymal cells can be met by cells of the fibroblast line 3T3 (but not by supernatants from these cells). To our knowledge, these findings provide the first direct evidence that mesenchymal as well as epithelial cells are involved in T-cell development, and suggest that their involvement is stage-specific and likely to be dependent on short-range or contact-mediated interactions.
RP ANDERSON, G (corresponding author), UNIV BIRMINGHAM,SCH MED,DEPT ANAT,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND.
FU Wellcome Trust Funding Source: Medline
NR 20
TC 302
Z9 337
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 70
EP 73
DI 10.1038/362070a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600063
PM 8446171
DA 2026-03-10
ER

PT J
AU TOYOSHIMA, C
   SASABE, H
   STOKES, DL
AF TOYOSHIMA, C
   SASABE, H
   STOKES, DL
TI 3-DIMENSIONAL CRYOELECTRON MICROSCOPY OF THE CALCIUM-ION PUMP IN THE SARCOPLASMIC-RETICULUM MEMBRANE
SO NATURE
LA English
DT Article
ID functional consequences; transmembrane domain; x-ray; ca-2+-atpase; mutations; organization; diffraction; location; proteins; sector
AB THE ATP-driven calcium pump (Ca2+-ATPase) is an integral membrane protein (M(r) 110K) which relaxes striated muscle by pumping calcium out of the cytoplasm into the sarcoplasmic reticulum against a large concentration gradient1. Recent efforts have attempted to relate the sequence of Ca2+-ATPase to its structure and function. In particular, site-directed mutagenesis has identified critical amino-acid residues2-6, and its predicted secondary structure, which includes ten transmembrane helices7, has gained experimental support8-10. But direct visualization of the molecule has so far been limited to the cytoplasmic domains at low resolution11,12. We present here the three-dimensional structure of Ca2+-ATPase in the native sarcoplasmic reticulum membrane at 14 angstrom resolution, determined by cryo-electron microscopy and helical image analysis. The structure shows an unexpected transmembrane organization, consisting of three distinct segments, one of which is highly inclined. These features can be related to earlier predictions of secondary structure.
C1 UNIV VIRGINIA, HLTH SCI CTR,DEPT MOLEC PHYSIOL & BIOL PHYS, JORDAN HALL,BOX 449, CHARLOTTESVILLE, VA 22908 USA.
   TOKYO INST TECHNOL, DEPT BIOL SCI, MEGURO KU, TOKYO 152, JAPAN.
   RIKEN, FRONTIER RES PROGRAM, WAKO, SAITAMA 35101, JAPAN.
C3 University of Virginia; Institute of Science Tokyo; Tokyo Institute of Technology; RIKEN
NR 21
TC 218
Z9 230
U1 1
U2 10
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 469
EP 471
DI 10.1038/362469a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400090
PM 8385269
DA 2026-03-10
ER

PT J
AU ANGELL, CA
   LIU, C
   SANCHEZ, E
AF ANGELL, CA
   LIU, C
   SANCHEZ, E
TI RUBBERY SOLID ELECTROLYTES WITH DOMINANT CATIONIC TRANSPORT AND HIGH AMBIENT CONDUCTIVITY
SO NATURE
LA English
DT Article
ID viscosity
AB EFFORTS to develop a high-voltage, lightweight rechargeable battery for electrically powered vehicles have focused on batteries based on solid electrolytes, which offer good mechanical strength, easy packaging and high energy densities. An important objective is to identify an electrolyte with the desired combination of mechanical properties, electrical conductivity and stability against powerfully oxidizing and reducing electrodes (lithium is preferred for the anode). Among the most promising materials are rubbery 'salt-in-polymer' electrolytes and highly conducting but brittle superionic glass electrolytes. In the latter category are salts with good lithium-ion conductivity, which are compatible with lithium-anode systems. Here we describe new ionic conductors-'polymer-in-salt' materials-in which lithium salts are mixed with small quantities of the polymers polypropylene oxide and polyethylene oxide. These materials have glass transitions low enough to remain rubbery at room temperature while preserving good lithium-ion conductivities and high electrochemical stability.
RP ANGELL, CA (corresponding author), ARIZONA STATE UNIV,DEPT CHEM,TEMPE,AZ 85287, USA.
NR 19
TC 527
Z9 590
U1 8
U2 336
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 137
EP 139
DI 10.1038/362137a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800052
DA 2026-03-10
ER

PT J
AU STURCHIO, NC
   DUNKLEY, PN
   SMITH, M
AF STURCHIO, NC
   DUNKLEY, PN
   SMITH, M
TI CLIMATE-DRIVEN VARIATIONS IN GEOTHERMAL ACTIVITY IN THE NORTHERN KENYA RIFT-VALLEY
SO NATURE
LA English
DT Article
ID lake-level fluctuations; pleistocene
AB HIGH-TEMPERATURE continental geothermal systems are primarily associated with volcanic activity at plate margins1. It has long been known that the activity of these geothermal systems is intermittent, and this is generally attributed to the effect of magmatic intrusions or fault motions. Recently, however, it has also been recognized2-4 that surface-water hydrology and climate variations can influence the evolution of individual silicic caldera-hosted geothermal systems, although it is difficult to judge the general importance of such effects in controlling the long-term behaviour of continental geothermal systems. Here we report uranium-series ages for the hydrothermal deposits of past geothermal activity from several Quaternary volcanic centres in the northern Kenya rift valley. We find that the ages correspond well to periods of high lake level within the rift, suggesting that the elevated water table and increased availability of meteoric water associated with more humid climates can promote greater transfer of heat and mass from deep, long-lived heat sources to the surface.
C1 BRITISH GEOL SURVEY,KEYWORTH NG12 5GG,NOTTS,ENGLAND.
C3 UK Research & Innovation (UKRI); Natural Environment Research Council (NERC); NERC British Geological Survey
RP STURCHIO, NC (corresponding author), ARGONNE NATL LAB,GEOSCI CMT-205,ARGONNE,IL 60439, USA.
NR 18
TC 50
Z9 53
U1 1
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 233
EP 234
DI 10.1038/362233a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600051
DA 2026-03-10
ER

PT J
AU HENDERSON, CE
   CAMU, W
   METTLING, C
   GOUIN, A
   POULSEN, K
   KARIHALOO, M
   RULLAMAS, J
   EVANS, T
   MCMAHON, SB
   ARMANINI, MP
   BERKEMEIER, L
   PHILLIPS, HS
   ROSENTHAL, A
AF HENDERSON, CE
   CAMU, W
   METTLING, C
   GOUIN, A
   POULSEN, K
   KARIHALOO, M
   RULLAMAS, J
   EVANS, T
   MCMAHON, SB
   ARMANINI, MP
   BERKEMEIER, L
   PHILLIPS, HS
   ROSENTHAL, A
TI NEUROTROPHINS PROMOTE MOTOR-NEURON SURVIVAL AND ARE PRESENT IN EMBRYONIC LIMB BUD
SO NATURE
LA English
DT Article
ID tyrosine kinase receptor; nerve growth-factor; expression; trkb; motoneurons; bdnf; culture; system; gene
AB Embryonic spinal motor neurons are thought to depend for survival on unidentified factors secreted both by their peripheral targets and by cells within the central nervous system1. The neurotrophins are a family of polypeptides required for survival of discrete central and peripheral neuronal populations in vivo and in vitro2,3.  In spite of their ability to reduce motor neuron death in vivo4-6, the known neurotrophins have been thought to be without direct effect on motor neurons7-10. Here we show that picomolar concentrations of three of them, brain-derived neurotrophic factor, neurotrophin-3 and neurotrophin-5, can prevent the death of cultured embryonic rat spinal motor neurons. Furthermore, messenger RNA coding for neurotrophins is present at appropriate stages in spinal cord and limb bud, and mRNA for their receptors is found in motor neurons. These neurotrophins may therefore be physiological motor neuron growth factors.
C1 GENENTECH INC,DEPT CELL ANAL,S SAN FRANCISCO,CA 94080.
   UMDS,DEPT PHYSIOL,LONDON SE1 7EH,ENGLAND.
   GENENTECH INC,DEPT NEUROSCI,S SAN FRANCISCO,CA 94080.
C3 Roche Holding; Genentech; Roche Holding USA; University of London; King's College London; Roche Holding; Genentech; Roche Holding USA
RP HENDERSON, CE (corresponding author), CTR RECH BIOCHIM MACROMOLEC,CNRS,UPR 9008,INSERM,U249,BP 5051,F-34033 MONTPELLIER,FRANCE.
NR 32
TC 581
Z9 658
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 266
EP 270
DI 10.1038/363266a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600054
PM 8487864
DA 2026-03-10
ER

PT J
AU MULLER, CB
   SCHMIDHEMPEL, P
AF MULLER, CB
   SCHMIDHEMPEL, P
TI EXPLOITATION OF COLD TEMPERATURE AS DEFENSE AGAINST PARASITOIDS IN BUMBLEBEES
SO NATURE
LA English
DT Article
ID behavioral fever
AB PARASITES can modify host behaviour for their own benefit after infection1-4. Whether these changes also minimize loss of host fitness is less well known5-7. Although parasitoids are abundant8, few cases are known of behavioural changes in host-parasitoid systems9. Bumblebees (Bombus spp., Apidae, Hymenoptera) are primitively eusocial insects with an annual life cycle. Reproduction occurs in late summer when males and young queens are released10,11. Parasitoid conopid flies (Conopidae, Diptera) are abundant in summer, and up to 70% of field-caught bumblebee workers may be parasitized12. Development of the parasitoid usually takes 10-12 days and ends with the host's death when the larva pupates. Here we report a novel strategy used against these parasitoids, based on the exploitation of temperature effects on parasite development. We demonstrate that parasitized workers of the bumblebee Bombus terrestris L. stay in the field overnight rather than returning to their nest. This behaviour retards the development of the parasite and reduces the chances of successful development. In choice experiments, parasitized foragers actively seek out cold temperatures. This behaviour therefore enhances colony success by prolonging the life of parasitized workers while at the same time reducing parasitoid fitness.
C1 ETH ZURICH,INST TERR OEKOL,CH-8952 SCHLIEREN,SWITZERLAND.
   UNIV BASEL,INST ZOOL,CH-4051 BASEL,SWITZERLAND.
C3 Swiss Federal Institutes of Technology Domain; ETH Zurich; University of Basel
NR 19
TC 116
Z9 123
U1 0
U2 56
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 65
EP 67
DI 10.1038/363065a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200058
DA 2026-03-10
ER

PT J
AU KAWAMURA, S
AF KAWAMURA, S
TI RHODOPSIN PHOSPHORYLATION AS A MECHANISM OF CYCLIC-GMP PHOSPHODIESTERASE REGULATION BY S-MODULIN
SO NATURE
LA English
DT Article
ID rod outer segments; light-activated phosphodiesterase; retinal rods; guanylate-cyclase; free calcium; adaptation; atp; membranes; kinetics; cascade
AB DURING light-adaptation by the vertebrate eye, the rods are desensitized and the light response is accelerated1,2. When light is absorbed by the rods, a phosphodiesterase is activated that hydrolyses cyclic GMP3,4. A light-induced decrease in cytoplasmic Ca2+ concentration5-7 is part of this light-adaptation process8,9. The protein S-modulin (M(r) 26,000) is known to increase the fraction of light-activated cyclic GMP-phosphodiesterase (PDE) at high Ca2+ concentrations in frog rod photoreceptors10. Here I present evidence that S-modulin lengthens the lifetime of active PDE (PDE*) at high Ca2+ Concentrations. These S-modulin effects are observed in the physiological range of Ca2+ concentration (30 nM to 1 muM; half-maximum effects at 200-400 nM). At the high Ca2+ concentrations at which S-modulin prolongs the lifetime of PDE*, S-modulin inhibits rhodopsin phosphorylation (half-maximum effect at approximately 100 nM Ca2+). ATP is necessary for the S-modulin effects on PDE activation. I therefore conclude that the Ca2+-dependent regulation of PDE by S-modulin is mediated by rhodopsin phosphorylation. This regulation seems to be the principal mechanism of light adaptation in vertebrate photoreceptors.
RP KAWAMURA, S (corresponding author), KEIO UNIV,SCH MED,DEPT PHYSIOL,SHINANO MACHI 35,SHINJUKU KU,TOKYO 160,JAPAN.
NR 23
TC 343
Z9 363
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 855
EP 857
DI 10.1038/362855a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300062
PM 8386803
DA 2026-03-10
ER

PT J
AU ODONOVAN, A
   WOOD, RD
AF ODONOVAN, A
   WOOD, RD
TI IDENTICAL DEFECTS IN DNA-REPAIR IN XERODERMA-PIGMENTOSUM GROUP-G AND RODENT ERCC GROUP-5
SO NATURE
LA English
DT Article
ID complementation group-g; cockayne syndrome; cell-extracts; group-a; microinjection; fibroblasts; radiation; protein
AB HUMANS with the complementation group G form of the inherited syndrome xeroderma pigmentosum (XP) are hypersensitive to solar ultraviolet light because of a defect in nucleotide-excision repair of DNA1-4. Some individuals are also affected with Cockayne's syndrome, and have neurological abnormalities. Here we report that the DNA repair deficiency of XP-G cell extracts can be corrected by addition of protein fractions from normal cells. Repair proficiency can also be restored by mixing XP-G cell extracts with extracts from different repair-defective cell lines, with one exception. Extracts from cells representing group 5 of a set of ultraviolet-sensitive rodent mutants fail to complement XP-G extracts. XP-G and group 5 correcting activities co-elute after approximately 1,000-fold purification from HeLa cells. An antibody directed against a recombinant fragment of the XP-G complementing protein (XPGC) inhibits excision repair by normal cell extracts, and activity can be restored with an XP-G/group 5 complementing fraction. These data strongly suggest that the XPGC and group 5 correcting (ERCC5) proteins are identical.
RP ODONOVAN, A (corresponding author), IMPERIAL CANC RES FUND,CLARE HALL LABS,BLANCHE LANE,S MIMMS EN6 3LD,HERTS,ENGLAND.
NR 28
TC 113
Z9 123
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 185
EP 188
DI 10.1038/363185a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100055
PM 8483505
DA 2026-03-10
ER

PT J
AU HUANG, ZJ
   EDERY, I
   ROSBASH, M
AF HUANG, ZJ
   EDERY, I
   ROSBASH, M
TI PAS IS A DIMERIZATION DOMAIN COMMON TO DROSOPHILA PERIOD AND SEVERAL TRANSCRIPTION FACTORS
SO NATURE
LA English
DT Article
ID dna-binding; gene-product; protein; clock; melanogaster; receptor; myc
AB MUTATIONS in the period gene product (PER) can shorten or lengthen the circadian rhythms of Drosophila melanogaster1, but its biochemical activity has not been established. PER contains a motif of approximately 270 amino acids whose function is unknown (termed PAS2) and which is also present in three transcription factors of the basic-helix-loop-helix (bHLH) type, in the D. melanogaster single-minded gene product (SIM)2, and in both subunits of the mammalian dioxin receptor complex3,4,28. We show here that the PER PAS functions in vitro as a novel protein dimerization motif and that it can mediate associations between different members of the PAS protein family. The dimerization efficiency is decreased by several missense mutations in the PAS domain, including the original per(L) mutation, which lengthens circadian periods from 24 h to 29 h (ref. 1). The results indicate that the PAS domain may function as a dimerization domain in both SIM and the dioxin receptor complex, and that PER may regulate circadian gene transcription partly by interacting with the PAS domain of bHLH-PAS-containing transcription factors.
C1 BRANDEIS UNIV, DEPT BIOL, HOWARD HUGHES MED INST, WALTHAM, MA 02254 USA.
C3 Howard Hughes Medical Institute; Brandeis University
NR 27
TC 453
Z9 538
U1 0
U2 42
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 259
EP 262
DI 10.1038/364259a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300064
PM 8391649
DA 2026-03-10
ER

PT J
AU DAVIES, K
AF DAVIES, K
TI IMPRINTING MAKES ITS MARK
SO NATURE
LA English
DT Article
ID disomy
NR 11
TC 5
Z9 5
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 94
EP 94
DI 10.1038/363094a0
PG 1
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200068
DA 2026-03-10
ER

PT J
AU ORCI, L
   PALMER, DJ
   AMHERDT, M
   ROTHMAN, JE
AF ORCI, L
   PALMER, DJ
   AMHERDT, M
   ROTHMAN, JE
TI COATED VESICLE ASSEMBLY IN THE GOLGI REQUIRES ONLY COATOMER AND ARF PROTEINS FROM THE CYTOSOL
SO NATURE
LA English
DT Article
ID adp-ribosylation factor; gtp-binding protein; beta-cop; clathrin; transport; stack; pits; endocytosis; dissection; membranes
AB TRANSPORT vesicles derived from the Golgi apparatus are thought to mediate biosynthetic transport across the Golgi stack1-3. These vesicles are surrounded by a protein coat4 whose principal constituents are coatomer (a complex of seven distinct subunits or COPs)5 and ADP-ribosylation factor (ARF, an N-myristylated small GTP-binding protein). The coat proteins of the COP-coated vesicles were originally defined by ultrastructural criteria4-9, however, and it is possible that important but minor coat proteins or cytoplasmic proteins needed for coat assembly may have been overlooked. Here we show that coatomer and ARF are the only cytoplasmic proteins needed for the assembly and budding of COP-coated vesicles. COP-coated buds may therefore form essentially by self-assembly from Golgi cisternae after an initial step in which GTP is used to allow ARF binding.
C1 MEM SLOAN KETTERING CANC CTR, CELLULAR BIOCHEM & BIOPHYS PROGRAM, NEW YORK, NY 10021 USA.
C3 Memorial Sloan Kettering Cancer Center
RP ORCI, L (corresponding author), UNIV GENEVA, MED CTR, DEPT MORPHOL, 1 RUE MICHEL SERVET, CH-1211 GENEVA, SWITZERLAND.
NR 26
TC 203
Z9 218
U1 1
U2 7
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 732
EP 734
DI 10.1038/364732a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700063
PM 8355790
DA 2026-03-10
ER

PT J
AU TODO, T
   TAKEMORI, H
   RYO, H
   IHARA, M
   MATSUNAGA, T
   NIKAIDO, O
   SATO, K
   NOMURA, T
AF TODO, T
   TAKEMORI, H
   RYO, H
   IHARA, M
   MATSUNAGA, T
   NIKAIDO, O
   SATO, K
   NOMURA, T
TI A NEW PHOTOREACTIVATING ENZYME THAT SPECIFICALLY REPAIRS ULTRAVIOLET LIGHT-INDUCED (6-4)PHOTOPRODUCTS
SO NATURE
LA English
DT Article
ID escherichia-coli; pyrimidine dimer; binding-proteins; human-cells; dna; sequence; photoproducts; establishment; purification; damage
AB CYCLOBUTANE pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone photoproducts ((6-4)photoproducts) are the two major classes of cytotoxic, mutagenic and carcinogenic DNA photoproducts produced by ultraviolet light irradiation of cells1-4. The phenomenon of photoreactivation, the reduction of the lethal and mutagenic effects of ultraviolet radiation by simultaneous or subsequent irradiation with near ultraviolet or visible light, has been identified in several organisms and in some cases the enzymes that catalyse this process have been characterized in sufficient detail5. CPDs are the only known substrate for the photoreactivating enzymes so far analysed and enzymatic photoreactivation of (6-4)photoproducts has not yet been reported4,5. We report here that an enzyme that catalyses the light-dependent repair of (6-4)photoproduct exists in Drosophila melanogaster. This is, to our knowledge, the first report of such photoreactivating activity specific for (6-4)photoproducts in any organism.
C1 NARA MED UNIV,DEPT BIOL,KASHIHARA,NARA 634,JAPAN.
   KANAZAWA UNIV,FAC PHARMACEUT SCI,DIV RADIAT BIOL,KANAZAWA,ISHIKAWA 920,JAPAN.
   OSAKA UNIV,SCH MED,DEPT DERMATOL,OSAKA 553,JAPAN.
C3 Nara Medical University; Kanazawa University; University of Osaka
RP TODO, T (corresponding author), OSAKA UNIV,FAC MED,DEPT RADIAT BIOL,YAMADA OKA 2-2,SUITA,OSAKA 565,JAPAN.
NR 21
TC 259
Z9 282
U1 1
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 371
EP 374
DI 10.1038/361371a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000064
PM 8426655
DA 2026-03-10
ER

PT J
AU LU, B
   FU, WM
   GREENGARD, P
   POO, MM
AF LU, B
   FU, WM
   GREENGARD, P
   POO, MM
TI CALCITONIN GENE-RELATED PEPTIDE POTENTIATES SYNAPTIC RESPONSES AT DEVELOPING NEUROMUSCULAR-JUNCTION
SO NATURE
LA English
DT Article
ID nicotinic acetylcholine-receptor; chick skeletal-muscle; embryonic neuron; rapid induction; initial events; spinal-cord; phosphorylation; myotubes; desensitization; culture
AB PROTEIN phosphorylation is important in synaptic transmission and plasticity1. At the neuromuscular junction, phosphorylation of acetylcholine (ACh) receptor-channels increases the rate of agonist-induced channel desensitization2. In contrast, potentiation of ACh channel activity through protein phosphorylation has not been described. We report here that calcitonin gene-related peptide (CGRP), a neuropeptide present at presynaptic motor nerve terminals3,4, enhances the postsynaptic response at developing neuromuscular junctions by increasing the burst duration of embryonic ACh channels. The effect of CGRP on these ACh channels is mimicked by dibutyryl-cyclic AMP and by cAMP-dependent protein kinase (PKA) and prevented by a specific peptide inhibitor of PKA. Moreover, postsynaptic inhibition of PKA reduced the amplitude and decay time of spontaneous synaptic currents, suggesting that endogenous CGRP may act as a potentiating factor during the early phase of synaptogenesis.
C1 COLUMBIA UNIV,DEPT BIOL SCI,NEW YORK,NY 10027.
C3 Columbia University
RP LU, B (corresponding author), ROCKEFELLER UNIV,MOLEC & CELLULAR NEUROSCI LAB,NEW YORK,NY 10021, USA.
NR 28
TC 110
Z9 116
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 76
EP 79
DI 10.1038/363076a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200063
PM 7683114
DA 2026-03-10
ER

PT J
AU HUMLER, E
   THIROT, JL
   MONTAGNER, JP
AF HUMLER, E
   THIROT, JL
   MONTAGNER, JP
TI GLOBAL CORRELATIONS OF MID-OCEAN-RIDGE BASALT CHEMISTRY WITH SEISMIC TOMOGRAPHIC-IMAGES
SO NATURE
LA English
DT Article
ID mantle wave velocity; southeast indian ridge; east pacific rise; atlantic ridge; geochemical variations; lateral heterogeneity; triple junction; earth structure; rayleigh-waves; anisotropy
AB THERMAL Convection in the mantle is the most important dynamic process in the Earth's interior. Two quite different approaches are currently used to provide and analyse information regarding lateral temperature variations in the upper mantle. On the one hand, the major-element chemistry of basalts erupted at mid-ocean ridges is directly influenced by the temperature of the mantle beneath1-5; on the other, seismic velocity studies6-17 can be used to map lateral temperature variations on a global scale (lower seismic velocities corresponding to higher mantle temperatures). Here we make a first attempt at relating these two approaches, by examining the global co-variation between mid-ocean-ridge basalt chemistry and upper-mantle shear-wave velocity. We find a strong correlation between basalt chemistry and variations in seismic velocity at depths of 100-170 km and lateral scale-lengths of 1,000-2,400 km, supporting a common thermal origin for the two types of signal. The departure of a few points from the general correlation may either reflect locally poor resolution of the tomographic model or, more interestingly, point to real anomalies that will repay closer examination.
C1 COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964.
   INST PHYS GLOBE,SEISMOL LAB,F-75252 PARIS 05,FRANCE.
C3 Columbia University; Universite Paris Cite
RP HUMLER, E (corresponding author), INST PHYS GLOBE,GEOCHIM & COSMOCHIM LAB,4 PL JUSSIEU,F-75252 PARIS 05,FRANCE.
NR 51
TC 27
Z9 28
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 225
EP 228
DI 10.1038/364225a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300053
DA 2026-03-10
ER

PT J
AU GACZYNSKA, M
   ROCK, KL
   GOLDBERG, AL
AF GACZYNSKA, M
   ROCK, KL
   GOLDBERG, AL
TI GAMMA-INTERFERON AND EXPRESSION OF MHC GENES REGULATE PEPTIDE HYDROLYSIS BY PROTEASOMES
SO NATURE
LA English
DT Article
ID major histocompatibility complex; class-i molecules; antigen presentation; lymphocyte-t; linked lmp; proteinase; ubiquitin; subunits
AB THE presentation of intracellular proteins to the immune system requires their degradation to small peptides1,2 that then become associated with major histocompatibility complex (MHC) class I molecules3,4. The generation of these peptides may involve the 20S or 26S proteasome particles, which contain multiple proteolytic activities5-14 including distinct sites that preferentially cleave small peptides on the carboxyl side of hydrophobic, basic or acidic residues6,13,14. Degradation of most cell proteins requires their conjugation to ubiquitin before hydrolysis by the 26S proteasome6,13-16. This large complex contains the 20S proteasome as its proteolytic core6,14,16-18. This ubiquitin-dependent proteolytic pathway is implicated in MHC class I presentation11,12. Gamma-interferon (gamma-IFN, a stimulator of antigen presentation1, induces a subclass of proteasomes that contain two MHC-encoded subunits, LMP2 and 7 (refs 5-10). Here we show that gamma-interferon alters the peptidase activities of the 20S and 26S proteasomes without affecting the rates of breakdown of proteins or of ubiquitinated proteins. By enhancing the expression of MHC genes, gamma-IFN increases the proteasomes' capacity to cleave small peptides after hydrophobic and basic residues but reduces cleavage after acidic residues. Moreover, proteasomes of mutants lacking LMP subunits show decreased rates of cleavage after hydrophobic and basic residues. Thus, gamma-IFN and expression of these MHC genes should favour the production by proteasomes of the types of peptides found on MHC class I molecules, which terminate almost exclusively with hydrophobic or basic residues19.
C1 HARVARD UNIV,SCH MED,DEPT PATHOL,BOSTON,MA 02115.
   HARVARD UNIV,SCH MED,DANA FARBER CANC INST,BOSTON,MA 02115.
C3 Harvard University; Harvard Medical School; Harvard University; Harvard University Medical Affiliates; Dana-Farber Cancer Institute; Harvard Medical School
RP GACZYNSKA, M (corresponding author), HARVARD UNIV,SCH MED,DEPT CELLULAR & MOLEC PHYSIOL,BOSTON,MA 02115, USA.
NR 28
TC 553
Z9 611
U1 0
U2 14
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 264
EP 267
DI 10.1038/365264a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100058
PM 8396732
DA 2026-03-10
ER

PT J
AU BEATTIE, P
AF BEATTIE, P
TI URANIUM THORIUM DISEQUILIBRIA AND PARTITIONING ON MELTING OF GARNET PERIDOTITE
SO NATURE
LA English
DT Article
ID ocean-ridge basalts; east pacific rise; th-230-u-238 disequilibrium; isotopic geochemistry; upper mantle; tholeiites; systematics; lavas; volcanism; iceland
AB THE abundances of isotopes in the U-238 decay series can be used as both tracers and chronometers of magmatic processes. In the subsolidus asthenosphere, the activity of each daughter isotope (defined as the product of its concentration and decay constant, and denoted by parentheses) is assumed to be equal to that of its parent. By contrast, (Th-230/U-238) is greater than unity in most recent mid-ocean-ridge and ocean-island basalts1, implying that thorium is more incompatible (that is, it is partitioned into the melt phase more strongly) than uranium. Melting of spinel peridotite cannot produce the (Th-230) excesses, because measured partition coefficients for pyroxenes and olivine demonstrate that uranium is more incompatible than thorium for this rock2. Here I report garnet-melt partitioning data which show that for this mineral-melt pair thorium does behave more incompatibly than uranium, thus supporting the suggestion that mid-ocean-ridge basalts (MORB) are produced by melting initiated at depths where garnet is stable3-6. Using these data, I show that the observed (Th-230/U-238) ratios of MORB and most ocean-island basalts can be explained by slow, near-fractional melting initiated in the garnet stability field.
RP BEATTIE, P (corresponding author), UNIV CAMBRIDGE,DEPT EARTH SCI,CAMBRIDGE CB2 3EQ,ENGLAND.
NR 30
TC 243
Z9 258
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 63
EP 65
DI 10.1038/363063a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200057
DA 2026-03-10
ER

PT J
AU ABBOTT, A
   BUTLER, D
AF ABBOTT, A
   BUTLER, D
TI WORKING IN A WIDER EUROPE
SO NATURE
LA English
DT Article
NR 0
TC 0
Z9 0
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 751
EP 754
DI 
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900064
DA 2026-03-10
ER

PT J
AU FENTON, B
   GLOVER, DM
AF FENTON, B
   GLOVER, DM
TI A CONSERVED MITOTIC KINASE ACTIVE AT LATE ANAPHASE TELOPHASE IN SYNCYTIAL DROSOPHILA EMBRYOS
SO NATURE
LA English
DT Article
ID saccharomyces-cerevisiae; protein-kinase; polo
AB MUTATIONS in the Drosophila gene polo cause abnormal mitotic and meiotic divisions1,2. This gene encodes a 577-amino-acid protein that has an N-terminal putative kinase domain and a 300-residue C-terminal domain2. In budding yeast, a homologous kinase is encoded by CDC5 (ref. 3), a gene required for nuclear division late in the mitotic cycle4 and during meiosis5. Murine homologues have also been described6,7. Here we show that the polo gene product immunoprecipitated from extracts of single Drosophila embryos can phosphorylate casein in vitro, and that the kinase activity peaks cyclically at late anaphase/telophase. This contrasts with the cyclical activity of cyclin B-associated p34cdc2 kinase, which is maximal upon entry into mitosis during the rapid cycles of mitosis in the syncytium.
C1 UNIV DUNDEE, INST MED SCI,DEPT ANAT & PHYSIOL, CANC RES CAMPAIGN,CELL CYCLE GENET GRP, DUNDEE DD1 4HN, SCOTLAND.
C3 University of Dundee
NR 17
TC 117
Z9 129
U1 0
U2 2
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 637
EP 640
DI 10.1038/363637a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900059
PM 8510757
DA 2026-03-10
ER

PT J
AU COLGAN, J
   WAMPLER, S
   MANLEY, JL
AF COLGAN, J
   WAMPLER, S
   MANLEY, JL
TI INTERACTION BETWEEN A TRANSCRIPTIONAL ACTIVATOR AND TRANSCRIPTION FACTOR-IIB INVIVO
SO NATURE
LA English
DT Article
ID rna polymerase-ii; dna-binding; initiation; proteins; complex; mediate
AB TRANSCRIPTION of messenger RNA-encoding genes in vitro requires many protein factors1,2. Transcription factor IID, possibly with the cooperation of TFIIA, binds to the TATA element of the promoter3-5, forming a complex that can bind TFIIB (refs 6, 7) followed by RNA polymerase II (refs 6, 8) and other factors9. One or more of these steps is thought to be facilitated by gene-specific transcriptional activation proteins10-12; this seems to require TFIID-associated auxiliary factors13-15 and may involve direct contact between the activator and TFIID16,17 and/or TFIIB18,19. If such contact is necessary in vivo, activation might conceivably be blocked by a TFIIB derivative containing the sequences necessary for this interaction, but lacking those necessary for binding to the rest of the transcriptional apparatus, an effect similar to that referred to as squelching20 or transcriptional interference21. Here we show that the activity of the glutamine-rich fushi tarazu activation domain is indeed blocked by truncated TFIIB derivatives in Drosophila Schneider L2 cells, suggesting that it is mediated by interactions with TFIIB.
C1 UNIV CALIF SAN DIEGO,DEPT BIOL,LA JOLLA,CA 92093.
   UNIV CALIF SAN DIEGO,CTR MOLEC GENET,LA JOLLA,CA 92093.
C3 University of California System; University of California San Diego; University of California System; University of California San Diego
RP COLGAN, J (corresponding author), COLUMBIA UNIV,DEPT BIOL SCI,NEW YORK,NY 10027, USA.
NR 31
TC 78
Z9 80
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 549
EP 553
DI 10.1038/362549a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300057
PM 8464496
DA 2026-03-10
ER

PT J
AU JOHNSSON, K
   ALLEMANN, RK
   WIDMER, H
   BENNER, SA
AF JOHNSSON, K
   ALLEMANN, RK
   WIDMER, H
   BENNER, SA
TI SYNTHESIS, STRUCTURE AND ACTIVITY OF ARTIFICIAL, RATIONALLY DESIGNED CATALYTIC POLYPEPTIDES
SO NATURE
LA English
DT Article
ID alpha-helix dipole; bundle protein; decarboxylation; acid
AB BIOLOGICAL macromolecules with catalytic activity can be created artificially using two approaches. The first exploits a system that selects a few catalytically active biomolecules from a large pool of randomly generated (and largely inactive) molecules. Catalytic antibodies1 and many catalytic RNA molecules2 are obtained in this way. The second involves rational design of a biomolecule that folds in solution to present to the substrate an array of catalytic functional groups3-8. Here we report the synthesis of rationally designed polypeptides that catalyse the decarboxylation of oxaloacetate via an imine intermediate. We determine the secondary structures of the polypeptides by two-dimensional NMR spectroscopy. We are able to trap and identify intermediates in the catalytic cycle, and to explore the kinetics in detail. The formation of the imine by our artificial oxaloacetate decarboxylases is three to four orders of magnitude faster than can be achieved with simple amine catalysts: this performance rivals that of typical catalytic antibodies.
C1 SWISS FED INST TECHNOL,ORGAN CHEM LAB,CH-8092 ZURICH,SWITZERLAND.
   UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720.
   SANDOZ PHARMA LTD,PRECLIN RES,CH-4002 BASEL,SWITZERLAND.
C3 Swiss Federal Institutes of Technology Domain; ETH Zurich; University of California System; University of California Berkeley; Novartis; Sandoz
NR 42
TC 205
Z9 232
U1 2
U2 47
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 530
EP 532
DI 10.1038/365530a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100047
PM 8413606
DA 2026-03-10
ER

PT J
AU MUMMERT, E
   GRIMM, R
   SPETH, V
   ECKERSKORN, C
   SCHILTZ, E
   GATENBY, AA
   SCHAFER, E
AF MUMMERT, E
   GRIMM, R
   SPETH, V
   ECKERSKORN, C
   SCHILTZ, E
   GATENBY, AA
   SCHAFER, E
TI A TCP1-RELATED MOLECULAR CHAPERONE FROM PLANTS REFOLDS PHYTOCHROME TO ITS PHOTOREVERSIBLE FORM
SO NATURE
LA English
DT Article
ID ribulosebisphosphate carboxylase; mitochondrial protein; purification; bacterial; groel
AB FOLDING of the major cytoskeletal components in the cytosol of mammalian cells is mediated by interactions with t-complex polypeptide-1 (TCP1) molecular chaperones1-6, a situation analogous to the chaperonin 60-aided folding of polypeptides in bacteria7,8, chloroplasts9,10 and mitochondria11-13. We have purified a TCP1-related molecular chaperone from etiolated oat seedlings that has a unique structure. Although immunologically related to TCP1, and having amino-acid sequence similarity, its quaternary structure is different from animal TCP1 proteins5,6,14. Electron microscopy and image analysis reveals that the chaperone has two stacked rings of six subunits each, and is distinct in size and configuration. The chaperone copurifies with the soluble cytosolic photoreceptor phytochrome15, and can stimulate refolding of denatured phytochrome to a photoactive form in the presence of Mg-ATP. We propose that this protein is the cytosolic chaperone involved in phytochrome biogenesis in plant cells.
C1 MAX PLANCK INST BIOCHEM,GENZENTRUM,W-8033 MARTINSRIED,GERMANY.
   INST BIOL 2,W-7800 FREIBURG,GERMANY.
   INST ORGAN CHEM & BIOCHEM,W-7800 FREIBURG,GERMANY.
   DUPONT CO INC,CENT RES & DEV,DIV MOLEC BIOL,WILMINGTON,DE 19880.
C3 Max Planck Society; DuPont; DuPont USA
NR 33
TC 44
Z9 44
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 644
EP 648
DI 10.1038/363644a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900061
PM 8099715
DA 2026-03-10
ER

PT J
AU AZZOPARDI, P
   COWEY, A
AF AZZOPARDI, P
   COWEY, A
TI PREFERENTIAL REPRESENTATION OF THE FOVEA IN THE PRIMARY VISUAL-CORTEX
SO NATURE
LA English
DT Article
ID cortical magnification factor; lateral geniculate-nucleus; ganglion-cell density; macaque monkeys; striate cortex; retina; field; uniformity; neurons; vision
AB THE retinal fovea, which corresponds to the central degree or so of vision, is spatially over-represented in the visual cortex. It is about 0.01% of retina area, but at least 8% of the striate cortex1-3. Does this simply reflect an equivalently uneven distribution of ganglion cells in the retina4-7, or is the cortical representation of the fovea preferentially expanded8-13? The answer hinges on the resolution of long-standing discrepancies between the retinal and cortical magnification factors. We approached the problem in a different way, using a retrograde transneuronal tracer from cortex to retina to relate directly the number of ganglion cells projecting to marked areas of striate cortex. We report here that ganglion cells near the fovea were allocated 3.3 to 5.9 times more cortical tissue than more peripheral ones, and conclude that the cortical representation of the most central retina is much greater than expected from the density of its ganglion cells.
RP AZZOPARDI, P (corresponding author), UNIV OXFORD,DEPT EXPTL PSYCHOL,S PARKS RD,OXFORD OX1 3UD,ENGLAND.
NR 30
TC 144
Z9 169
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 719
EP 721
DI 10.1038/361719a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900054
PM 7680108
DA 2026-03-10
ER

PT J
AU LAMPITT, RS
   HILLIER, WR
   CHALLENOR, PG
AF LAMPITT, RS
   HILLIER, WR
   CHALLENOR, PG
TI SEASONAL AND DIEL VARIATION IN THE OPEN OCEAN CONCENTRATION OF MARINE SNOW AGGREGATES
SO NATURE
LA English
DT Article
ID deep-ocean; zooplankton; behavior; flux; sea
AB MARINE snow, generally defined as aggregated particles of diameter greater than 0.5 mm, is thought to play an important role in oceanic biogeochemical cycles1. Recent studies have focused on its unusual physical, biological and chemical properties but its temporal variability has received scant attention 2-6. Here we report observations of the abundance, volume concentration and size distribution of marine snow over a five-month period at a single site in the Northeast Atlantic. At a depth of 270 m, marine snow particles demonstrated strong seasonal and diel variability. Volume concentrations in spring were about 20 times those in summer and autumn with late morning concentrations up to three times higher than at other times of the day. Our results suggest that the marine snow forms as a result of highly dynamic interactions in the particle pool. We believe that the mid-water biota and their migratory behaviour are responsible for the diel variability; they are therefore likely to have a significant influence on marine snow concentrations and hence on open-ocean material flux.
RP LAMPITT, RS (corresponding author), INST OCEANOG SCI, DEACON LAB, GODALMING GU8 5UB, SURREY, ENGLAND.
NR 19
TC 144
Z9 153
U1 0
U2 45
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 737
EP 739
DI 10.1038/362737a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000051
DA 2026-03-10
ER

PT J
AU MCCORMICK, D
   HODGSON, J
AF MCCORMICK, D
   HODGSON, J
TI A WINDOW OF OPPORTUNITY
SO NATURE
LA English
DT Article
NR 3
TC 2
Z9 2
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 676
EP 678
DI 10.1038/365676a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600067
PM 8413633
DA 2026-03-10
ER

PT J
AU FAHEY, DW
   KAWA, SR
   WOODBRIDGE, EL
   TIN, P
   WILSON, JC
   JONSSON, HH
   DYE, JE
   BAUMGARDNER, D
   BORRMANN, S
   TOOHEY, DW
   AVALLONE, LM
   PROFFITT, MH
   MARGITAN, J
   LOEWENSTEIN, M
   PODOLSKE, JR
   SALAWITCH, RJ
   WOFSY, SC
   KO, MKW
   ANDERSON, DE
   SCHOEBERL, MR
   CHAN, KR
AF FAHEY, DW
   KAWA, SR
   WOODBRIDGE, EL
   TIN, P
   WILSON, JC
   JONSSON, HH
   DYE, JE
   BAUMGARDNER, D
   BORRMANN, S
   TOOHEY, DW
   AVALLONE, LM
   PROFFITT, MH
   MARGITAN, J
   LOEWENSTEIN, M
   PODOLSKE, JR
   SALAWITCH, RJ
   WOFSY, SC
   KO, MKW
   ANDERSON, DE
   SCHOEBERL, MR
   CHAN, KR
TI INSITU MEASUREMENTS CONSTRAINING THE ROLE OF SULFATE AEROSOLS IN MIDLATITUDE OZONE DEPLETION
SO NATURE
LA English
DT Article
ID high-altitude aircraft; heterogeneous chemistry; sulfate aerosols; er-2 aircraft; stratosphere; nitrogen; vortex; hole; n2o5; clo
AB In situ measurements of stratospheric sulphate aerosol, reactive nitrogen and chlorine concentrations at middle latitudes confirm the importance of aerosol surface reactions that convert active nitrogen to a less active, reservoir form. This makes mid-latitude stratospheric ozone less vulnerable to active nitrogen and more vulnerable to chlorine species. The effect of aerosol reactions on active nitrogen depends on gas phase reaction rates, so that increases in aerosol concentration following volcanic eruptions will have only a limited effect on ozone depletion at these latitudes.
C1 UNIV COLORADO,NOAA,COOPERAT INST RES ENVIRONM SCI,BOULDER,CO 80309.
   UNIV DENVER,DEPT ENGN,DENVER,CO 80208.
   NATL CTR ATMOSPHER RES,BOULDER,CO 80307.
   UNIV CALIF IRVINE,DEPT GEOSCI,IRVINE,CA 92717.
   HARVARD UNIV,DEPT CHEM,CAMBRIDGE,MA 02138.
   JET PROP LAB,PASADENA,CA 91109.
   NASA,AMES RES CTR,MOFFETT FIELD,CA 94035.
   HARVARD UNIV,DEPT EARTH & PLANETARY SCI,CAMBRIDGE,MA 02138.
   ATMOSPHER & ENVIRONM RES INC,CAMBRIDGE,MA 02139.
   JOHNS HOPKINS UNIV,APPL PHYS LAB,LAUREL,MD 20723.
   NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771.
C3 University of Colorado System; University of Colorado Boulder; National Oceanic Atmospheric Admin (NOAA) - USA; University of Denver; National Center Atmospheric Research (NCAR) - USA; University of California System; University of California Irvine; Harvard University; National Aeronautics & Space Administration (NASA); NASA Jet Propulsion Laboratory (JPL); National Aeronautics & Space Administration (NASA); NASA Ames Research Center; Harvard University; Atmospheric & Environmental Research; Johns Hopkins University; Johns Hopkins University Applied Physics Laboratory; National Aeronautics & Space Administration (NASA); NASA Goddard Space Flight Center
RP FAHEY, DW (corresponding author), NOAA,AERON LAB,BOULDER,CO 80303, USA.
NR 51
TC 250
Z9 267
U1 1
U2 37
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 509
EP 514
DI 10.1038/363509a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900039
DA 2026-03-10
ER

PT J
AU FONG, TM
   CASCIERI, MA
   YU, H
   BANSAL, A
   SWAIN, C
   STRADER, CD
AF FONG, TM
   CASCIERI, MA
   YU, H
   BANSAL, A
   SWAIN, C
   STRADER, CD
TI AMINO AROMATIC INTERACTION BETWEEN HISTIDINE-197 OF THE NEUROKININ-1 RECEPTOR AND CP-96345
SO NATURE
LA English
DT Article
ID substance-p receptor; molecular characterization; functional cdna; antagonist; peptides; proteins; neurons; binding; potent; rings
AB SUBSTANCE P is a peptide neurotransmitter that binds to the neurokinin-1 receptor and is involved in pain transmission and neurogenic inflammation1-4. Recently, a non-peptide substance P antagonist (CP 96345) has been shown to be effective in animal models of pain and inflammation5,6. An understanding of the molecular interactions responsible for ligand binding will be critical for the development of more specific and selective antagonists for the neurokinin-I receptor and for the discovery of new antagonists for related G-protein-coupled receptors. Here we report that histidine at position 197 in the fifth transmembrane helix of the human neurokinin-1 receptor binds specifically to CP 96345 but not to peptide agonists. Substitution of His 197 by different amino acids and analysis of structural analogues of antagonists suggest that His 197 is involved in an amino-aromatic interaction with the benzhydryl moiety of CP 96345.
C1 MERCK SHARP & DOHME LTD, NEUROSCI RES CTR, HARLOW CM20 2PT, ESSEX, ENGLAND.
C3 Merck & Company; Merck & Company United Kingdom
RP FONG, TM (corresponding author), MERCK RES LABS, DEPT MOLEC PHARMACOL & BIOCHEM 80M213, POB 2000, RAHWAY, NJ 07065 USA.
NR 25
TC 213
Z9 214
U1 0
U2 4
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 350
EP 353
DI 
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600063
PM 8384323
DA 2026-03-10
ER

PT J
AU BRENNWALD, P
   NOVICK, P
AF BRENNWALD, P
   NOVICK, P
TI INTERACTIONS OF 3 DOMAINS DISTINGUISHING THE RAS-RELATED GTP-BINDING PROTEINS YPT1 AND SEC4
SO NATURE
LA English
DT Article
ID vesicular transport; terminal domain; yeast; gap; secretion; identification; signal; p21
AB THE genes SEC4 and YPT1 encode Ras-related GTP-binding proteins in the yeast Saccharomyces cerevisiae. Ypt1 is necessary for vesicular transport from the endoplasmic reticulum to the Golgi1-4, whereas Sec4 is required for fusion of post-Golgi secretory vesicles to the plasma membrane5. Recently, three structural domains have been proposed to specify the stage in cellular transport at which members of the Sec4/Ypt1/Rab family act: the effector domain6, the C-terminal hypervariable region7, and a region corresponding to loop 7 in the structure of p21ras (ref. 8). Here we use Sec4/Ypt1 chimaeras to show that these three regions cooperate to specify Ypt1 function and that the C-terminal hypervariable region is needed for Ypt1 localization to the Golgi. Unexpectedly, we found that a single chimaera can function as either Ypt1 or Sec4 without missorting carboxypeptidase Y or invertase.
RP BRENNWALD, P (corresponding author), YALE UNIV,SCH MED,DEPT CELL BIOL,333 CEDAR ST,NEW HAVEN,CT 06510, USA.
NR 27
TC 178
Z9 191
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 560
EP 563
DI 10.1038/362560a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300060
PM 8464498
DA 2026-03-10
ER

PT J
AU KUBO, Y
   BALDWIN, TJ
   JAN, YN
   JAN, LY
AF KUBO, Y
   BALDWIN, TJ
   JAN, YN
   JAN, LY
TI PRIMARY STRUCTURE AND FUNCTIONAL EXPRESSION OF A MOUSE INWARD RECTIFIER POTASSIUM CHANNEL
SO NATURE
LA English
DT Article
ID guinea-pig heart; egg cell-membrane; k+ channel; ventricular cells; anomalous rectification; xenopus oocytes; magnesium block; mammalian brain; internal mg-2+; messenger-rna
AB A complementary DNA encoding an inward rectifier K+ channel (IRK1) was isolated from a mouse macrophage cell line by expression cloning. This channel conducts inward K+ current below the K+ equilibrium potential but passes little outward K+ current. The IRK1 channel contains only two putative transmembrane segments per subunit and corresponds to the inner core structure of voltage-gated K+ channels. The IRK1 channel and an ATP-regulated K+ channel show extensive sequence similarity and constitute a new superfamily.
C1 UNIV CALIF SAN FRANCISCO,HOWARD HUGHES MED INST,SAN FRANCISCO,CA 94143.
   UNIV CALIF SAN FRANCISCO,DEPT PHYSIOL,SAN FRANCISCO,CA 94143.
   UNIV CALIF SAN FRANCISCO,DEPT BIOCHEM,SAN FRANCISCO,CA 94143.
C3 University of California System; University of California San Francisco; Howard Hughes Medical Institute; University of California System; University of California San Francisco; University of California System; University of California San Francisco
NR 52
TC 996
Z9 1105
U1 0
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 127
EP 133
DI 10.1038/362127a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800049
PM 7680768
DA 2026-03-10
ER

PT J
AU SINGER, MC
   THOMAS, CD
   PARMESAN, C
AF SINGER, MC
   THOMAS, CD
   PARMESAN, C
TI RAPID HUMAN-INDUCED EVOLUTION OF INSECT HOST ASSOCIATIONS
SO NATURE
LA English
DT Article
ID oviposition preferences; population; diet; performance; herbivore; patterns; range
AB RAPID evolution of host association is now occurring independently in two populations of the host-specialist butterfly Euphydryas editha, each of which has recently incorporated a novel host species into its diet. The reasons for these episodes of rapid evolution lie in human land use practices: logging in one case and cattle ranching in the other. In contrast to other insects that have used tolerance of human activities to expand their ranges into disturbed habitats1-3, these rare butterflies have remained at their original sites and evolved adaptations to the changes occurring at those sites. At both sites, the proportion of insects preferring the novel host has increased, in one case clearly because of genetic changes in the insect population. This process is now starting to generate insects that refuse to accept their ancestral host, foreshadowing a new problem in conservation biology. By adapting genetically to human-induced changes in their habitat, the insects risk becoming dependent on continuation of the same practices. This is a serious risk, because human cultural evolution can be even faster than the rapid genetic adaptation that the insects can evidently achieve.
C1 UNIV BIRMINGHAM,SCH BIOL SCI,EDGBASTON B15 2TT,ENGLAND.
C3 University of Birmingham
RP SINGER, MC (corresponding author), UNIV TEXAS,DEPT ZOOL,AUSTIN,TX 78712, USA.
NR 31
TC 214
Z9 238
U1 0
U2 104
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 681
EP 683
DI 10.1038/366681a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500068
DA 2026-03-10
ER

PT J
AU DOWLING, TE
   DEMARAIS, BD
AF DOWLING, TE
   DEMARAIS, BD
TI EVOLUTIONARY SIGNIFICANCE OF INTROGRESSIVE HYBRIDIZATION IN CYPRINID FISHES
SO NATURE
LA English
DT Article
ID number; trees
AB BOTANISTS have long recognized introgressive hybridization as important in the evolution of plants1,2. Hybridization among animals is also common3, yet few zoologists have considered it evolutionarily important4-6. We report here that in the genus Gila, a morphologically diverse group of minnows from western North America7, we have discovered a pervasive influence of hybridization throughout their evolutionary histories. Gene exchange among distinctive forms has contributed to existing diversity, supporting the hypothesis that introgressive hybridization can play a significant role in evolution of vertebrates.
RP DOWLING, TE (corresponding author), ARIZONA STATE UNIV,DEPT ZOOL,TEMPE,AZ 85287, USA.
NR 37
TC 188
Z9 214
U1 0
U2 29
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 444
EP 446
DI 10.1038/362444a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400081
DA 2026-03-10
ER

PT J
AU SHENKER, A
   LAUE, L
   KOSUGI, S
   MERENDINO, JJ
   MINEGISHI, T
   CUTLER, GB
AF SHENKER, A
   LAUE, L
   KOSUGI, S
   MERENDINO, JJ
   MINEGISHI, T
   CUTLER, GB
TI A CONSTITUTIVELY ACTIVATING MUTATION OF THE LUTEINIZING-HORMONE RECEPTOR IN FAMILIAL MALE PRECOCIOUS PUBERTY
SO NATURE
LA English
DT Article
ID alpha-1b-adrenergic receptor; chorionic-gonadotropin; sexual precocity; gene; substitutions; rhodopsin; rat; lh
AB FAMILIAL male precocious puberty (FMP) is a gonadotropin-independent disorder that is inherited in an autosomal dominant, male-limited pattern1-5. Affected males generally exhibit signs of puberty by age 4. Testosterone production and Leydig cell hyperplasia occur in the context of prepubertal levels of luteinizing hormone (LH)3-5. The LH receptor is a member of the family of G-protein-coupled receptors6,7, and we hypothesized that FMPP might be due to a mutant receptor that is activated in the presence of little or no agonist8-12 . A single A --> G base change that results in substitution of glycine for aspartate at position 578 in the sixth transmembrane helix of the LH receptor was found in affected individuals from eight different families. Linkage of the mutation to FMPP was supported by restriction-digest analysis. COS-7 cells expressing the mutant LH receptor exhibited markedly increased cyclic AMP production in the absence of agonist, suggesting that autonomous Leydig cell activity in FMPP is caused by a constitutively activated LH receptor.
C1 NIDDK,BIOCHEM & METAB LAB,CELL REGULAT SECT,BETHESDA,MD 20892.
   NICHHD,DEV ENDOCRINOL BRANCH,BETHESDA,MD 20892.
   KYOTO UNIV,SCH MED,DEPT LAB MED,KYOTO 606,JAPAN.
   GUNMA UNIV,SCH MED,DEPT OBSTET & GYNECOL,MAEBASHI,GUNMA 371,JAPAN.
C3 National Institutes of Health (NIH) - USA; NIH National Institute of Diabetes & Digestive & Kidney Diseases (NIDDK); National Institutes of Health (NIH) - USA; NIH Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD); Kyoto University; Gunma University
RP SHENKER, A (corresponding author), NIDDK,MOLEC PATHOPHYSIOL BRANCH,BLDG 10,ROOM 8C-101,BETHESDA,MD 20892, USA.
NR 30
TC 610
Z9 661
U1 0
U2 19
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 652
EP 654
DI 10.1038/365652a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600060
PM 7692306
DA 2026-03-10
ER

PT J
AU HIROI, Z
   TAKANO, M
   AZUMA, M
   TAKEDA, Y
AF HIROI, Z
   TAKANO, M
   AZUMA, M
   TAKEDA, Y
TI A NEW FAMILY OF COPPER-OXIDE SUPERCONDUCTORS SRN+1CUNO2N+1+DELTA STABILIZED AT HIGH-PRESSURE
SO NATURE
LA English
DT Article
ID cu-o system; tc
AB THE search for new copper oxide superconductors' has been pursued mainly by exploring a range of chemical compositions (counter-cations and oxygen content) and reaction temperatures. We have explored the effects of an additional variable, the reaction pressure, and have thereby synthesized some new compounds, including (Ca1-ySry)1-xCuO2 which shows superconductivity at 110 K (refs 2, 3). Here we report the synthesis of a new family of high-pressure phases with the formula Srn+1CunO2n+1+delta (n = 1, 2, 3,...) extending from Sr2CuO3.1 (n = 1) to SrCuO2 (n = infinity)4. Sr2CuO3.1 and Sr3Cu2O5+delta' (n = 2) are superconductors with transition temperatures (T(c)) of 70 and 100 K, respectively. The metal sublattice of Sr2CuO3.1 is of the tetragonal K2NiF4 (or Nd2CuO4) type with lattice constants a = 3.764 angstrom and c = 12.548 angstrom, and iodometric measurements suggest that nearly half of the oxygen atoms are missing from the counter-layers to Sr2O1.1. Homogeneous pyramidal or octahedral coordination, which has generally been believed to be indispensable to attain T(c)s of approximately 100 K, is thus absent. The n = 2 and 3 members seem to correspond to the high-pressure phases in the Ca-Sr-Cu-O system recently reported by Adachi et al.5.
C1 MIE UNIV,FAC ENGN,DEPT CHEM,TSU,MIE 514,JAPAN.
C3 Mie University
RP HIROI, Z (corresponding author), KYOTO UNIV,INST CHEM RES,UJI,KYOTO 611,JAPAN.
NR 12
TC 232
Z9 239
U1 7
U2 88
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 315
EP 317
DI 10.1038/364315a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000049
DA 2026-03-10
ER

PT J
AU KEYS, JG
   JOHNSTON, PV
   BLATHERWICK, RD
   MURCRAY, FJ
AF KEYS, JG
   JOHNSTON, PV
   BLATHERWICK, RD
   MURCRAY, FJ
TI EVIDENCE FOR HETEROGENEOUS REACTIONS IN THE ANTARCTIC AUTUMN STRATOSPHERE
SO NATURE
LA English
DT Article
ID nitric-acid; trace gases; ozone
AB REACTIVE chlorine compounds are known to cause ozone depletion in the Antarctic stratosphere, but they can be bound into an inactive form through reactions with nitrogen dioxide. In the spring, NO2 can be converted to a long-lived reservoir species, HNO3, on the surface of polar stratospheric clouds1,2. This removes NO2 from the stratosphere and allows chlorine-catalysed ozone destruction to proceed. It has been suggested that similar reactions may take place on background sulphate aerosols in the Antarctic stratosphere3, but as yet there has been no unambiguous evidence for these reactions in the absence of polar stratospheric clouds (although there have been observations of ozone loss attributed to volcanic aerosols4,5). Here we present measurements of Antarctic stratospheric NO2 and HNO3 concentrations taken in 1991. Our results demonstrate that reactive nitrogen was converted to HNO3 in autumn, before temperatures were low enough for polar stratospheric clouds to form. We conclude that heterogeneous chemistry on background aerosols was responsible for this conversion, which brought with it the potential for additional ozone loss in the autumn.
C1 UNIV DENVER,DEPT PHYS,DENVER,CO 80208.
C3 University of Denver
RP KEYS, JG (corresponding author), NATL INST WATER & ATMOSPHER RES,LAUDER,NEW ZEALAND.
NR 24
TC 17
Z9 17
U1 2
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 49
EP 51
DI 10.1038/361049a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800042
DA 2026-03-10
ER

PT J
AU DIAZ, S
   GRIME, JP
   HARRIS, J
   MCPHERSON, E
AF DIAZ, S
   GRIME, JP
   HARRIS, J
   MCPHERSON, E
TI EVIDENCE OF A FEEDBACK MECHANISM LIMITING PLANT-RESPONSE TO ELEVATED CARBON-DIOXIDE
SO NATURE
LA English
DT Article
ID co2 enrichment; growth; ecosystems; soil; populations; nutrition; tundra
AB IN short-term experiments under productive laboratory conditions, native herbaceous plants differ widely in their potential to achieve higher yields at elevated concentrations of atmospheric carbon dioxide1-8. The most responsive species appear to be large fast-growing perennials of recently disturbed fertile soils7,8. These types of plants are currently increasing in abundance9 but it is not known whether this is an effect of rising carbon dioxide or is due to other factors. Doubts concerning the potential of natural vegetation for sustained response to rising carbon dioxide have arisen from experiments on infertile soils, where the stimulus to growth was curtailed by mineral nutrient limitations2,3,10. Here we present evidence that mineral nutrient constraints on the fertilizer effect of elevated carbon dioxide can also occur on fertile soil and in the earliest stages of secondary succession. Our data indicate that there may be a feedback mechanism in which elevated carbon dioxide causes an increase in substrate release into the rhizosphere by non-mycorrhizal plants, leading to mineral nutrient sequestration by the expanded microflora and a consequent nutritional limitation on plant growth.
C1 UNIV SHEFFIELD,DEPT ANIM & PLANT SCI,NERC,COMPARAT PLANT ECOL UNIT,SHEFFIELD S10 2TN,S YORKSHIRE,ENGLAND.
   UNIV E LONDON,ENVIRONM & IND RES UNIT,LONDON E15 4LZ,ENGLAND.
C3 UK Research & Innovation (UKRI); Natural Environment Research Council (NERC); University of Sheffield; University of East London
RP DIAZ, S (corresponding author), NATL UNIV CORDOBA,FAC CIENCIAS EXACTAS FIS & NAT,C CORREO 495,RA-5000 CORDOBA,ARGENTINA.
NR 28
TC 455
Z9 520
U1 2
U2 146
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 616
EP 617
DI 10.1038/364616a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100049
DA 2026-03-10
ER

PT J
AU MINTY, A
   CHALON, P
   DEROCQ, JM
   DUMONT, X
   GUILLEMOT, JC
   KAGHAD, M
   LABIT, C
   LEPLATOIS, P
   LIAUZUN, P
   MILOUX, B
   MINTY, C
   CASELLAS, P
   LOISON, G
   LUPKER, J
   SHIRE, D
   FERRARA, P
   CAPUT, D
AF MINTY, A
   CHALON, P
   DEROCQ, JM
   DUMONT, X
   GUILLEMOT, JC
   KAGHAD, M
   LABIT, C
   LEPLATOIS, P
   LIAUZUN, P
   MILOUX, B
   MINTY, C
   CASELLAS, P
   LOISON, G
   LUPKER, J
   SHIRE, D
   FERRARA, P
   CAPUT, D
TI INTERLEUKIN-13 IS A NEW HUMAN LYMPHOKINE REGULATING INFLAMMATORY AND IMMUNE-RESPONSES
SO NATURE
LA English
DT Article
ID t-cell clone; human-monocytes; sequence; th1; identification; lymphocytes; cytokines; receptor; antigen; signal
AB THE discovery of new cytokines normally relies on a prior knowledge of at least one of their biological effects, which is used as a criterion either for the purification of the protein or for the isolation of the complementary DNA by expression cloning. However, the redundancy of cytokine activities complicates the discovery of novel cytokines in this way, and the pleiotropic nature of many cytokines means that the principal activities of a new cytokine may bear little relation to that used for its isolation. We have adopted an alternative approach which relies on differential screening of an organized subtracted cDNA library from activated peripheral blood mononuclear cells, using the inducibility of lymphokine messenger RNAs by anti-CD28 as a primary screening criterion. The ligation of the CD28 antigen on the T lymphocyte by a surface antigen, B7/BB-1, expressed on activated B lymphocytes and monocytes1,2 is a key step in the activation of T lymphocytes and the accumulation of lymphokine mRNAs3. Here we report the discovery by molecular cloning of a new interleukin (interleukin-13 or IL-13) expressed in activated human T lymphocytes. Recombinant IL-13 protein inhibits inflammatory cytokine production induced by lipopolysaccharide in human peripheral blood monocytes. Moreover, it synergizes with IL-2 in regulating interferon-gamma synthesis in large granular lymphocytes. Recent mapping of the IL-13 gene shows that it is closely linked to the IL-4 gene on chromosome 5q 23-31 (ref. 4). Interleukin-13 may be critical in regulating inflammatory and immune responses.
C1 SANOFI ELF BIO RECH,F-31676 LABEGE,FRANCE.
   SANOFI RECH,F-34184 MONTPELLIER,FRANCE.
C3 Sanofi-Aventis; Sanofi-Aventis; Sanofi France
NR 28
TC 907
Z9 1054
U1 0
U2 31
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 248
EP 250
DI 10.1038/362248a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600057
PM 8096327
DA 2026-03-10
ER

PT J
AU RUIZLAPUENTE, P
   JEFFERY, DJ
   CHALLIS, PM
   FILIPPENKO, AV
   KIRSHNER, RP
   HO, LC
   SCHMIDT, BP
   SANCHEZ, F
   CANAL, R
AF RUIZLAPUENTE, P
   JEFFERY, DJ
   CHALLIS, PM
   FILIPPENKO, AV
   KIRSHNER, RP
   HO, LC
   SCHMIDT, BP
   SANCHEZ, F
   CANAL, R
TI A POSSIBLE LOW-MASS TYPE-IA SUPERNOVA
SO NATURE
LA English
DT Article
ID da white-dwarfs; space density; spectra; sn-1991t; detonations; evolution; explosion; helium; stars
AB IN the standard model for type Ia supernovae1, a massive white dwarf in a binary system accretes matter from the companion star until it reaches the Chandrasekhar mass (the stability limit for degenerate-electron stars, corresponding to approximately 1.4 solar masses), and a runaway thermonuclear explosion ensues. In a popular variant of this model2, the companion star is also a white dwarf. But regardless of the nature of the companion, the invariance of the Chandrasekhar mass implies that all type Ia supernovae will be similar in luminosity3, making them ideal 'standard candles' for determining extragalactic distances, and hence the Hubble constant. In the context of the standard model, the recent type Ia supernova SN1991bg is hard to explain: it was underluminous at all observed epochs, leading to suggestions4,5 that the mass of the progenitor was unusually low. Here we present model calculations, based on more recent spectra, which point to a mass of the white dwarf of approximately 0.7 solar masses-well below the Chandrasekhar mass. Moreover, the late spectrum shows evidence of emission from low-velocity hydrogen gas, which might originate in material stripped from an extended, hydrogen-rich companion star. If our interpretation is correct, SN1991bg challenges both the double white-dwarf scenario, and the standard model for type Ia supernovae.
C1 UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720.
   UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720.
   INST ASTROFIS CANARIAS,LA LAGUNA,SPAIN.
   UNIV BARCELONA,DEPT ASTRON METEOROL,BARCELONA 7,SPAIN.
C3 University of California System; University of California Berkeley; University of California System; University of California Berkeley; Instituto de Astrofisica de Canarias; University of Barcelona
RP RUIZLAPUENTE, P (corresponding author), HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138, USA.
NR 30
TC 68
Z9 73
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 728
EP 730
DI 10.1038/365728a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200053
DA 2026-03-10
ER

PT J
AU WANG, QD
   LI, ZY
   BEGELMAN, MC
AF WANG, QD
   LI, ZY
   BEGELMAN, MC
TI THE X-RAY-EMITTING TRAIL OF THE NEARBY PULSAR PSR1929+10
SO NATURE
LA English
DT Article
ID supernova remnant; proper motions; radio
AB PULSARS-rapidly spinning, highly magnetized neutron stars-are thought to lose their rotational energy through the emission of relativistic particles1,2. As the typical lifetime of a pulsar greatly exceeds that of the remnant of the supernova explosion in which it was born, the relativistic wind from older pulsars should interact directly with the interstellar medium; this can give rise to observable pulsar-wind nebulae3. Here we report the detection by the X-ray satellite Rosat of a different type of nebula, associated with the nearby pulsar PSR1929 + 10. The nebula appears as a linear diffuse X-ray feature in the direction opposite to the pulsar's proper motion. In this case, the pulsar wind appears to be confined by the ram-pressure arising from the high velocity of the pulsar through the interstellar medium, resulting in a trail of relativistic electrons with enhanced emissions of synchrotron radiation. Many such nebulae may exist in the solar neighbourhood, but they will be difficult to detect except in those relatively rare cases where the traits point nearly towards us.
RP WANG, QD (corresponding author), UNIV COLORADO,NATL INST STAND & TECHNOL,JOINT INST LAB ASTROPHYS,BOULDER,CO 80302, USA.
NR 22
TC 56
Z9 59
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 127
EP 129
DI 10.1038/364127a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700041
DA 2026-03-10
ER

PT J
AU THEWISSEN, JGM
   HUSSAIN, ST
AF THEWISSEN, JGM
   HUSSAIN, ST
TI ORIGIN OF UNDERWATER HEARING IN WHALES
SO NATURE
LA English
DT Article
ID mammals
AB ALL described fossil and Recent cetaceans have relatively similar ear bones (malleus, incus and stapes) that strongly diverge from those of land mammals1-4. Here we report that the hearing organ of the oldest whale, Pakicetus, is the only known intermediate between that of land mammals and aquatic cetaceans (whales, dolphins and porpoises). The incus of Pakicetus is intermediate with respect to inflation, crural proportions, and position of the mallear joint. The incus and mandible of Pakicetus indic-ate that the path of soundwaves to its ear resembled that of land mammals. These fossils suggest that the first whale was amphibious, and corroborate the hypothesis that artiodactyls (for example, pigs, camels and ruminants) are the closest extant relatives of cetaceans.
C1 HOWARD UNIV, COLL MED, DEPT ANAT, WASHINGTON, DC 20059 USA.
C3 Howard University
RP THEWISSEN, JGM (corresponding author), DUKE UNIV, SCH MED, DEPT BIOL ANTHROPOL & ANAT, DURHAM, NC 27710 USA.
NR 28
TC 57
Z9 66
U1 0
U2 58
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 444
EP 445
DI 10.1038/361444a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300058
PM 8429882
DA 2026-03-10
ER

PT J
AU MARTIN, J
   MAYHEW, M
   LANGER, T
   HARTL, FU
AF MARTIN, J
   MAYHEW, M
   LANGER, T
   HARTL, FU
TI THE REACTION CYCLE OF GROEL AND GROES IN CHAPERONIN-ASSISTED PROTEIN-FOLDING
SO NATURE
LA English
DT Article
ID escherichia-coli; ribulosebisphosphate carboxylase; molecular chaperone; atp hydrolysis; purification; cooperativity; surface
AB The reaction mechanism of protein folding by the chaperonin GroEL and its regulator GroES has been defined. GroES and substrate protein counteract each other's effects on GroEL: whereas GroES stabilizes GroEL in the ADP-bound state, binding of unfolded polypeptide within the cavity of the GroEL cylinder triggers ADP and GroES release. Upon ADP-ATP exchange, GroES reassociates with GroEL and ATP hydrolysis discharges the bound protein for folding. Partially folded protein rebinds to the chaperonin, thus perpetuating the cycle until folding is complete.
C1 MEM SLOAN KETTERING CANC CTR, CELLULAR BIOCHEM & BIOPHYS PROGRAM, 1275 YORK AVE, NEW YORK, NY 10021 USA.
C3 Memorial Sloan Kettering Cancer Center
NR 31
TC 270
Z9 282
U1 0
U2 18
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 228
EP 233
DI 10.1038/366228a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500052
PM 7901770
DA 2026-03-10
ER

PT J
AU AMIN, J
   WEISS, DS
AF AMIN, J
   WEISS, DS
TI GABA(A) RECEPTOR NEEDS 2 HOMOLOGOUS DOMAINS OF THE BETA-SUBUNIT FOR ACTIVATION BY GABA BUT NOT BY PENTOBARBITAL
SO NATURE
LA English
DT Article
ID nicotinic acetylcholine-receptor; glycine receptor; alpha-subunit; binding-site; ion channels; amino-acids; a receptors; agonist; rat; neurons
AB THE predominant inhibitory neurotrasmitter of the brain, GABA (gamma-antinobutyric acid), activates chloride-selective ion pores integral to the receptor complex. Subunits comprising the presumed hetero-pentameric GABA channel have been cloned1-4, but little information is available on the domains important for activation. Rat wild-type or mutated alpha1-, beta2- and gamma2-subunits (designated alpha, beta and gamma) were coexpressed in Xenopus oocytes and examined electrophysiologically. We report here the identification of two separate and homologous domains of the beta-subunit, each of which contributes a tyrosine and threonine essential for activation by GABA. Conservative substitution of each of these four amino acids dramatically decreased GABA channel sensitivity to activation by GABA and the GABA agonist muscimol. These substitutions, however, did not impair activation by the barbiturate pentobarbital, indicating these two different classes of agonists activate GABA channels through distinct mechanisms. We also present evidence suggesting that the two identified domains of the beta-subunit contribute a major component of the GABA receptor.
C1 UNIV S FLORIDA,COLL MED,DEPT PHYSIOL & BIOPHYS,12901 BRUCE B DOWNS BLVD,TAMPA,FL 33612.
   UNIV S FLORIDA,COLL MED,INST BIOMOLEC SCI,TAMPA,FL 33612.
C3 State University System of Florida; University of South Florida; State University System of Florida; University of South Florida
NR 34
TC 396
Z9 422
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 565
EP 569
DI 10.1038/366565a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800070
PM 7504783
DA 2026-03-10
ER

PT J
AU ROULEAU, GA
   MEREL, P
   LUTCHMAN, M
   SANSON, M
   ZUCMAN, J
   MARINEAU, C
   HOANGXUAN, K
   DEMCZUK, S
   DESMAZE, C
   PLOUGASTEL, B
   PULST, SM
   LENOIR, G
   BIJLSMA, E
   FASHOLD, R
   DUMANSKI, J
   DEJONG, P
   PARRY, D
   ELDRIGE, R
   AURIAS, A
   DELATTRE, O
   THOMAS, G
AF ROULEAU, GA
   MEREL, P
   LUTCHMAN, M
   SANSON, M
   ZUCMAN, J
   MARINEAU, C
   HOANGXUAN, K
   DEMCZUK, S
   DESMAZE, C
   PLOUGASTEL, B
   PULST, SM
   LENOIR, G
   BIJLSMA, E
   FASHOLD, R
   DUMANSKI, J
   DEJONG, P
   PARRY, D
   ELDRIGE, R
   AURIAS, A
   DELATTRE, O
   THOMAS, G
TI ALTERATION IN A NEW GENE ENCODING A PUTATIVE MEMBRANE-ORGANIZING PROTEIN CAUSES NEUROFIBROMATOSIS TYPE-2
SO NATURE
LA English
DT Article
ID bilateral acoustic neurofibromatosis; gradient gel-electrophoresis; human-chromosome 22; subunit nf-h; polyposis-coli; dna fragments; meningioma; talin; ezrin; homology
AB Neurofibromatosis type 2 (NF2) is a monogenic dominantly inherited disease predisposing carriers to develop nervous system tumours. To identify the genetic defect, the region between two flanking polymorphic markers on chromosome 22 was cloned and several genes identified. One is the site of germ-line mutations in NF2 patients and of somatic mutations in NF2-related tumours. Its deduced product has homology with proteins at the plasma membrane and cytoskeleton interface, a previously unknown site of action of tumour suppressor genes in humans.
C1 MONTREAL GEN HOSP,RES INST,MONTREAL H3G 1A4,QUEBEC,CANADA.
   INST CURIE,GENET TUMEURS LAB,INSERM,CJF 9201,F-75231 PARIS 05,FRANCE.
   CEDARS SINAI MED CTR,NEUROGENET LAB,LOS ANGELES,CA 90048.
   INT AGCY RES CANC,F-69372 LYON,FRANCE.
   UNIV AMSTERDAM,INST HUMAN GENET,1105 AZ AMSTERDAM,NETHERLANDS.
   UNIV ERLANGEN NURNBERG,INST HUMAN GENET,W-8520 ERLANGEN,GERMANY.
   KAROLINSKA INST,DEPT CLIN GENET,S-10401 STOCKHOLM 60,SWEDEN.
   LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,LIVERMORE,CA 94550.
   NCI,CLIN EPIDEMIOL BRANCH,BETHESDA,MD 20892.
C3 McGill University; UNICANCER; Universite PSL; Institut Curie; Institut National de la Sante et de la Recherche Medicale (Inserm); Cedars Sinai Medical Center; World Health Organization; International Agency for Research on Cancer (IARC); University of Amsterdam; University of Erlangen Nuremberg; Karolinska Institutet; United States Department of Energy (DOE); Lawrence Livermore National Laboratory; National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI)
RP ROULEAU, GA (corresponding author), MCGILL UNIV,CTR RECH NEUROSCI,MONTREAL H3A 2T5,QUEBEC,CANADA.
NR 43
TC 1205
Z9 1316
U1 0
U2 49
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 515
EP 521
DI 10.1038/363515a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900040
PM 8379998
DA 2026-03-10
ER

PT J
AU MORGAN, JP
   CHEN, YJ
AF MORGAN, JP
   CHEN, YJ
TI DEPENDENCE OF RIDGE-AXIS MORPHOLOGY ON MAGMA SUPPLY AND SPREADING RATE
SO NATURE
LA English
DT Article
ID east pacific rise; oceanic-crust; beneath; ophiolite; thickness; profiles; gravity; oman
AB WHY do some mid-ocean-ridge axes have as their topographic expression a median valley 1-2 km deep and 15 30 km wide, whereas others have an axial high 100-200 m high and 1-2 km wide? In general, median valleys exist at the axes of ridges spreading at half-rates less than approximately 20-25 mm yr-1, whereas axial highs are found at faster-spreading ridges1,2. A recent crustal genesis model3, incorporating hydrothermal cooling and crustal accretion by means of a magma lens, agrees well with observations of the spreading-rate dependence of axial morphology1,2, the depth of the axial magma chamber3,4 and the thickness of the ridge-axis lithosphere5,6. But there are several notable exceptions to the correlation between spreading rate and axial morphology, such as the Reykjanes Ridge, which spreads at 10 mm yr-1 but has an axial high. Here we show that by extending the model of ref 3 to include variations in crustal thickness, we can explain the observed dependence of axial morphology on crustal thickness and spreading rate. Our results suggest that the ultimate control on axial morphology is the thermal structure at the ridge axis, which is a function of both spreading rate and magmna supply.
C1 OREGON STATE UNIV,COLL OCEANOG,CORVALLIS,OR 97331.
C3 Oregon State University
RP MORGAN, JP (corresponding author), UCSD,INST GEOPHYS & PLANETARY PHYS,LA JOLLA,CA, USA.
NR 28
TC 209
Z9 235
U1 0
U2 31
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 706
EP 708
DI 10.1038/364706a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700053
DA 2026-03-10
ER

PT J
AU ELDRIDGE, MD
   MADDEN, PA
   FRENKEL, D
AF ELDRIDGE, MD
   MADDEN, PA
   FRENKEL, D
TI ENTROPY-DRIVEN FORMATION OF A SUPERLATTICE IN A HARD-SPHERE BINARY MIXTURE
SO NATURE
LA English
DT Article
AB A MIXTURE of two dissimilar species (A and B) may freeze to form a substitutionally ordered crystal, the structure of which can vary from a lattice with only a few atoms per unit cell to a complex 'superlattice'. For example, a mixture of sodium and zinc can form a solid with the AB13 structure with 112 atoms per unit cell1 (Fig. 1a). One might suspect that very specific energetic interactions are needed to stabilize a structure as complex as this. But recent experiments2,3 show that the AB13 structure is also formed in mixtures of spherical colloidal particles with different diameters, which interact only via simple repulsive potentials. This raises the possibility that the formation of an AB13 superlattice might be supported by entropic effects alone. To investigate this possibility, we present here computer simulations of a binary mixture of hard spheres. Our calculations show that entropy alone is indeed sufficient to stabilize the AB13 phase, and that the full phase diagram of this system is surprisingly complex. Our results also suggest that vitrification or slow crystal nucleation in experimental studies of colloidal hard spheres can prevent the formation of equilibrium phases.
C1 FOM, INST ATOM & MOLEC PHYS, 1098 SJ AMSTERDAM, NETHERLANDS.
C3 AMOLF
RP ELDRIDGE, MD (corresponding author), UNIV OXFORD, PHYS CHEM LAB, S PARKS RD, OXFORD OX1 3QZ, ENGLAND.
NR 19
TC 308
Z9 363
U1 3
U2 128
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 35
EP 37
DI 10.1038/365035a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600045
DA 2026-03-10
ER

PT J
AU KNOX, JC
AF KNOX, JC
TI LARGE INCREASES IN FLOOD MAGNITUDE IN RESPONSE TO MODEST CHANGES IN CLIMATE
SO NATURE
LA English
DT Article
ID holocene; record
AB RECENT examinations of the possible hydrological response to global warming have emphasized changes in average conditions, rather than individual flooding events1-5. Historical accounts suggest, however, that such events may have had a considerable regional impact6-9 even in the face of any relatively modest climate change8. Here I present a 7,000-year geological record of overbank floods for upper Mississippi river tributaries in mid-continent North America, which provides concrete evidence for a high sensitivity of flood occurrence to changing climate. During a warmer, drier period between about 3,300 and 5,000 years ago, the largest, extremely rare floods were relatively small-the size of floods that now occur about once every fifty years. After approximately 3,300 years ago, when the climate became cooler and wetter, an abrupt shift in flood behaviour occurred, with frequent floods of a size that now recurs only once every 500 years or more. Still larger floods occurred between about AD 1250 and 1450, during the transition from the medieval warm interval to the cooler Little ice Age. All of these changes were apparently associated with changes in mean annual temperature of only about 1-2-degrees-C and changes in mean annual precipitation of less-than-or-equal-to 10-20%.
RP KNOX, JC (corresponding author), UNIV WISCONSIN,DEPT GEOG,234 SCI HALL,MADISON,WI 53706, USA.
NR 30
TC 351
Z9 406
U1 0
U2 105
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 430
EP 432
DI 10.1038/361430a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300053
DA 2026-03-10
ER

PT J
AU GAETANI, GA
   GROVE, TL
   BRYAN, WB
AF GAETANI, GA
   GROVE, TL
   BRYAN, WB
TI THE INFLUENCE OF WATER ON THE PETROGENESIS OF SUBDUCTION-RELATED IGNEOUS ROCKS
SO NATURE
LA English
DT Article
ID medicine lake volcano; arm mountain massif; island-arc; ultramafic cumulate; phase-relations; fracture-zone; aleutian arc; basalts; ophiolite; lavas
AB THE presence of dissolved water can significantly change the sequence in which different minerals crystallize from a silicate magma1-3. This will alter the compositional path followed by residual liquids (the 'liquid line of descent'), and modify the types and compositions of crystals that accumulate at the site of cooling. The sharp decrease in the solubility of water in silicate melts with decreasing pressure makes direct measurements of pre-eruptive concentrations in magmas difficult because much of the dissolved water boils off before eruption. Here we report experimental results on the crystallization of basalts that contain substantial dissolved water (up to 6 wt%), and show how the results can be used to infer the amount of dissolved H2O involved in the petrogenesis of lavas that preserve a record of their liquid lines of descent, or the accumulated minerals left behind after solidification. The presence of abundant magmatic water is a signature of subduction-zone volcanism4, and can be used to associate a suite of magmas or igneous cumulates with a convergent-margin, back-arc or inter-arc tectonic setting.
C1 WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543.
C3 Woods Hole Oceanographic Institution
RP GAETANI, GA (corresponding author), MIT,DEPT EARTH ATMOSPHER & PLANETARY SCI,CAMBRIDGE,MA 02139, USA.
NR 43
TC 265
Z9 295
U1 1
U2 44
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 332
EP 334
DI 10.1038/365332a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600049
DA 2026-03-10
ER

PT J
AU BASHIR, ZI
   BORTOLOTTO, ZA
   DAVIES, CH
   BERRETTA, N
   IRVING, AJ
   SEAL, AJ
   HENLEY, JM
   JANE, DE
   WATKINS, JC
   COLLINGRIDGE, GL
AF BASHIR, ZI
   BORTOLOTTO, ZA
   DAVIES, CH
   BERRETTA, N
   IRVING, AJ
   SEAL, AJ
   HENLEY, JM
   JANE, DE
   WATKINS, JC
   COLLINGRIDGE, GL
TI INDUCTION OF LTP IN THE HIPPOCAMPUS NEEDS SYNAPTIC ACTIVATION OF GLUTAMATE METABOTROPIC RECEPTORS
SO NATURE
LA English
DT Article
ID long-term potentiation; protein kinase-c; rat hippocampus; blocks induction; striatal neurons; area ca1; acid; transmission; maintenance; stimulation
AB UNDERSTANDING the mechanisms of long-term potentiation (LTP) should provide insights into the molecular basis of learning and memory in vertebrates.  Ionotropic glutamate receptors play a central role in LTP; AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate) receptors and NMDA (N-methyl-D-aspartate) receptors mediate synaptic responses that are enhanced in LTP and, in addition, NMDA receptors are necessary for the induction of LTP in most pathways1. There is also circumstantial evidence that metabotropic glutamate receptors (mGluRs) may be involved in LTP because the specific mGluR agonist aminocyclopentane dicarboxylate can augment tetanus-induced LTP2 and, under certain circumstances, can itself induce a slow-onset potentiation3,4. But the absence of any effective mGluR antagonist has prevented the determination of whether mGluRs are involved in the induction of tetanus-induced LTP. We report here that (RS)-alpha-methyl-4-carboxyphenylglycine is a specific mGluR antagonist in the hippocampus and have used this compound to examine the nature of the involvement of mGluRs in LTP. We show that synaptic activation of mGluRs is necessary for the induction of both NMDA receptor-dependent and NMDA receptor-independent forms of LTP in the hippocampus.
C1 UNIV BRISTOL,SCH MED SCI,DEPT PHARMACOL,BRISTOL BS8 1TD,AVON,ENGLAND.
C3 University of Bristol
RP BASHIR, ZI (corresponding author), UNIV BIRMINGHAM,SCH MED,DEPT PHARMACOL,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND.
FU Wellcome Trust Funding Source: Medline
NR 36
TC 673
Z9 730
U1 1
U2 44
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 347
EP 350
DI 10.1038/363347a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700052
PM 8388549
DA 2026-03-10
ER

PT J
AU KOUVELIOTOU, C
   FISHMAN, GJ
   MEEGAN, CA
   PACIESAS, WS
   WILSON, RB
   VANPARADIJS, J
   PREECE, RD
   BRIGGS, MS
   PENDLETON, GN
   BROCK, MN
   KOSHUT, TM
   HORACK, JM
AF KOUVELIOTOU, C
   FISHMAN, GJ
   MEEGAN, CA
   PACIESAS, WS
   WILSON, RB
   VANPARADIJS, J
   PREECE, RD
   BRIGGS, MS
   PENDLETON, GN
   BROCK, MN
   KOSHUT, TM
   HORACK, JM
TI RECURRENT BURST ACTIVITY FROM THE SOFT GAMMA-RAY REPEATER SGR-1900+14
SO NATURE
LA English
DT Article
ID high-energy transient
AB OF the one thousand or so detected sources of cosmic gamma-ray bursts (GRBs), only three are known to have exhibited recurrent activity1-4. These events differ from the majority of GRBs in that they are of much shorter duration and have relatively soft spectra5. The recurrent sources can thus be considered as a distinct class of objects the soft gamma repeaters (SGRs). The embryonic distribution of the SGRs suggests that they are of galactic origin4, whereas the distribution6 of GRBs seems to be inconsistent with any known galactic source population. Here we report the detection by the Burst and Transient Source Experiment (BATSE)7 of three short, very soft transient events from a location consistent with that of the 'old' repeater SGR 1900 + 14 (ref. 8). Our results suggest that the SGR active phase lasts at least 13 years, which, in conjunction with the arguments for a galactic origin, lends support to suggestions4,5 that SGRs are neutron stars.
C1 UNIV ALABAMA, DEPT PHYS, HUNTSVILLE, AL 35899 USA.
   ASTRON INST ANTON PANNEKOEK, 1098 SJ AMSTERDAM, NETHERLANDS.
   CTR HIGH ENERGY ASTROPHYS, 1098 SJ AMSTERDAM, NETHERLANDS.
C3 University of Alabama System; University of Alabama Huntsville; University of Amsterdam
RP KOUVELIOTOU, C (corresponding author), NASA, GEORGE C MARSHALL SPACE FLIGHT CTR, SPACE SCI LAB, ES 66, HUNTSVILLE, AL 35812 USA.
NR 23
TC 98
Z9 99
U1 0
U2 0
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 728
EP 730
DI 10.1038/362728a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000047
DA 2026-03-10
ER

PT J
AU SVOBODA, K
   SCHMIDT, CF
   SCHNAPP, BJ
   BLOCK, SM
AF SVOBODA, K
   SCHMIDT, CF
   SCHNAPP, BJ
   BLOCK, SM
TI DIRECT OBSERVATION OF KINESIN STEPPING BY OPTICAL TRAPPING INTERFEROMETRY
SO NATURE
LA English
DT Article
ID force generation; invitro; microtubules; movement; molecules; assay; size; displacement; organelle; density
AB Do biological motors move with regular steps? To address this question, we constructed instrumentation with the spatial and temporal sensitivity to resolve movement on a molecular scale. We deposited silica beads carrying single molecules of the motor protein kinesin on microtubules using optical tweezers and analysed their motion under controlled loads by interferometry. We find that kinesin moves with 8-nm steps.
C1 ROWLAND INST SCI INC, 100 EDWIN LAND BLVD, CAMBRIDGE, MA 02142 USA.
   HARVARD UNIV, COMM BIOPHYS, CAMBRIDGE, MA 02138 USA.
   HARVARD UNIV, SCH MED, DEPT CELL BIOL, BOSTON, MA 02115 USA.
C3 Harvard University; Harvard University; Harvard Medical School
NR 49
TC 1618
Z9 1929
U1 6
U2 446
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 721
EP 727
DI 10.1038/365721a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200052
PM 8413650
DA 2026-03-10
ER

PT J
AU BARRES, BA
   RAFF, MC
AF BARRES, BA
   RAFF, MC
TI PROLIFERATION OF OLIGODENDROCYTE PRECURSOR CELLS DEPENDS ON ELECTRICAL-ACTIVITY IN AXONS
SO NATURE
LA English
DT Article
ID central-nervous-system; glial progenitor-cell; rat optic-nerve; neurons; chain; pdgf; localization; tetrodotoxin
AB OLIGODENDROCYTES myelinate axons in the vertebrate central nervous system. It would, therefore, make sense if axons played a part in controlling the number of oligodendrocytes that develop in a myelinated tract. Although oligodendrocytes themselves normally do not divide, the precursor cells that give rise to them do. Here we show that the proliferation of oligodendrocyte precursor cells in the developing rat optic nerve depends on electrical activity in neighbouring axons, and that this activity-dependence can be circumvented by experimentally increasing the concentration of platelet-derived growth factor, which is present in the optic nerve and stimulates these cells to proliferate in culture. These findings suggest that axonal electrical activity normally controls the production and/or release of the growth factors that are responsible for proliferation of oligodendrocyte precursor cells and thereby helps to control the number of oligodendrocytes that develop in the region.
RP BARRES, BA (corresponding author), UNIV LONDON UNIV COLL,DEPT BIOL,MRC,DEV NEUROBIOL PROGRAMME,MEDAWAR BLDG,LONDON WC1E 6BT,ENGLAND.
NR 24
TC 529
Z9 641
U1 1
U2 20
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 258
EP 260
DI 10.1038/361258a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400059
PM 8093806
DA 2026-03-10
ER

PT J
AU RUOFF, RS
   TERSOFF, J
   LORENTS, DC
   SUBRAMONEY, S
   CHAN, B
AF RUOFF, RS
   TERSOFF, J
   LORENTS, DC
   SUBRAMONEY, S
   CHAN, B
TI RADIAL DEFORMATION OF CARBON NANOTUBES BY VAN-DER-WAALS FORCES
SO NATURE
LA English
DT Article
ID c-60; fullerenes; graphite; growth; fibers; c70
AB THE discovery of carbon nanotubes1,2 has stimulated many theoretical studies of their physical properties3-12, and their bulk synthesis13 should soon make possible experimental measurements of these properties14. All studies so far have assumed that the nanotubes have perfect cylindrical symmetry. Here we show that van der Waals forces between adjacent nanotubes can deform them substantially, destroying this cylindrical symmetry. We present transmission electron microscopy images of two adjacent aligned tubes, about 100 angstrom in diameter, which show flattening of the tubes along the contact region. Calculations on two-layer nested nanotubes indicate that these deformations can be explained on the basis of van der Waals interactions. We predict that these effects should be observable at least for tubes as small as 20 angstrom in diameter, and suggest that they may have a significant influence on the tubes' physical properties.
C1 IBM CORP,THOMAS J WATSON RES CTR,YORKTOWN HTS,NY 10598.
   DUPONT CO INC,EXPTL STN,WILMINGTON,DE 19880.
C3 International Business Machines (IBM); IBM USA; DuPont; DuPont USA
RP RUOFF, RS (corresponding author), SRI INT,MOLEC PHYS LAB,MENLO PK,CA 94025, USA.
NR 25
TC 392
Z9 442
U1 3
U2 96
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 514
EP 516
DI 10.1038/364514a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700048
DA 2026-03-10
ER

PT J
AU KROGH, TE
   KAMO, SL
   SHARPTON, VL
   MARIN, LE
   HILDEBRAND, AR
AF KROGH, TE
   KAMO, SL
   SHARPTON, VL
   MARIN, LE
   HILDEBRAND, AR
TI U-PB AGES OF SINGLE SHOCKED ZIRCONS LINKING DISTAL K/T EJECTA TO THE CHICXULUB CRATER
SO NATURE
LA English
DT Article
AB MANY lines of evidence now support the identification of the Chicxulub structure, in Mexico, as a buried impact crater and the probable source of ejecta found in Cretaceous/Tertiary (K/T) boundary sections worldwide1-8. The question remains, however, of whether there might be additional craters of K/T age, which also contributed ejecta. Shocked zircons from a K/T ejecta layer in Colorado9 preserve a primary source age of 545 +/- 5 Myr, with variable degrees of isotopic resetting consistent with partial lead loss at the time of impact (65 Myr ago)10. Here we report that the impact breccia from Chicxulub contains zircons that are identical in age, texture and lead loss pattern to the Colorado zircons, and to some from the Beloc section in Haiti. U-Pb data for 18 of the 36 grains studied (from all three sites) fall on a single line as well as if they had come from a single sample. An additional source age of 418 +/- 6 Myr is found only in Chicxulub and Haiti, suggesting that the Haiti and Colorado ejecta might have sampled different parts of the target stratigraphy. As an the ejecta ages found so far are also found at Chicxulub, our results are consistent with this being the only significant continental K/T impact crater.
C1 LUNAR & PLANETARY INST, HOUSTON, TX 77058 USA.
   Univ Nacl Autonoma Mexico, INST GEOFIS, MEXICO CITY 04510, MEXICO.
   GEOL SURVEY CANADA, OTTAWA K1A 0Y3, ON, CANADA.
C3 Universidad Nacional Autonoma de Mexico; Natural Resources Canada; Lands & Minerals Sector - Natural Resources Canada; Geological Survey of Canada
RP KROGH, TE (corresponding author), ROYAL ONTARIO MUSEUM, JACK SATTERLY GEOCHRONOL LAB, 100 QUEENS PK, TORONTO M5S 2C6, ONTARIO, CANADA.
NR 17
TC 173
Z9 190
U1 1
U2 10
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 23
PY 1993
VL 366
IS 6457
BP 731
EP 734
DI 10.1038/366731a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MN264
UT WOS:A1993MN26400024
DA 2026-03-10
ER

PT J
AU HUERTA, PT
   LISMAN, JE
AF HUERTA, PT
   LISMAN, JE
TI HEIGHTENED SYNAPTIC PLASTICITY OF HIPPOCAMPAL CA1 NEURONS DURING A CHOLINERGICALLY INDUCED RHYTHMIC STATE
SO NATURE
LA English
DT Article
ID long-term potentiation; central-nervous-system; dentate gyrus; theta-rhythm; patterned stimulation; receptor subtypes; rat hippocampus; visual-cortex; induction; responses
AB BRAIN cholinergic neurons are critical for memory function1,2 and their loss may contribute to memory impairment in Alzheimer's disease3. One role of cholinergic neurons is to elicit an oscillatory activity called theta rhythm4 in the hippocampus, a brain region involved in memory processing5. Theta rhythm occurs during periods of learning6,7, but its effect on the synaptic plasticity that underlies learning remains unclear. We have studied synaptic plasticity in hippocampal slices during theta-frequency oscillations induced by a cholinergic agonist8-10. Here we report that during these oscillations, synapses are in a state of heightened plasticity and can be modified by what would otherwise be ineffective stimulation. This heightened plasticity is sensitive to the timing of incoming stimuli with respect to the oscillatory activity. The results suggest that cholinergic systems may affect memory formation through the induction of an oscillatory state in which the requirements for synaptic plasticity are dramatically altered.
C1 BRANDEIS UNIV, CTR COMPLEX SYST, WALTHAM, MA 02254 USA.
C3 Brandeis University
RP HUERTA, PT (corresponding author), BRANDEIS UNIV, DEPT BIOL, WALTHAM, MA 02254 USA.
NR 29
TC 482
Z9 546
U1 0
U2 17
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 723
EP 725
DI 10.1038/364723a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700060
PM 8355787
DA 2026-03-10
ER

PT J
AU LOGAN, D
   ABUGHAZALEH, R
   BLAKEMORE, W
   CURRY, S
   JACKSON, T
   KING, A
   LEA, S
   LEWIS, R
   NEWMAN, J
   PARRY, N
   ROWLANDS, D
   STUART, D
   FRY, E
AF LOGAN, D
   ABUGHAZALEH, R
   BLAKEMORE, W
   CURRY, S
   JACKSON, T
   KING, A
   LEA, S
   LEWIS, R
   NEWMAN, J
   PARRY, N
   ROWLANDS, D
   STUART, D
   FRY, E
TI STRUCTURE OF A MAJOR IMMUNOGENIC SITE ON FOOT-AND-MOUTH-DISEASE VIRUS
SO NATURE
LA English
DT Article
ID 3-dimensional structure; antigenic variation; crystal-structure; protein; resolution; sequence; fibronectin; antibody; refinement; location
AB ATTACHMENT of foot-and-mouth disease virus (FMDV) to its cellular receptor involves a long and highly antigenic loop containing the conserved sequence, Arg-Gly-Asp, a motif known to be a recognition element in many integrin-dependent cell adhesion processes1-7. In our original crystal structure of FMDV the Arg-Gly-Asp-containing loop ('the loop'), located between beta-strands G and H of capsid protein VP1, was disordered and hence essentially invisible. We previously surmised that its disorder is enhanced by a disulphide bond linking the base of the loop (Cys 134) to Cys 130 of VP2 (ref. 8). We report here the crystal structure of the virus in which this disulphide is reduced. Reduced virus retains infectivity and serological experiments suggest that some of the loop's internal structure is conserved8. But here its structure has become sufficiently ordered to allow us to describe an unambiguous conformation, which we relate to some key biological properties of the virus.
C1 UNIV OXFORD,MOLEC BIOPHYS LAB,REX RICHARDS BLDG,OXFORD OX1 3QU,ENGLAND.
   AFRC,INST ANIM HLTH,WOKING GU24 0NF,ENGLAND.
   WELLCOME RES LABS,DEPT MOLEC SCI,BECKENHAM BR3 3BS,KENT,ENGLAND.
C3 University of Oxford; UK Research & Innovation (UKRI); Biotechnology and Biological Sciences Research Council (BBSRC); Pirbright Institute; Babraham Institute; GlaxoSmithKline; Glaxosmithkline United Kingdom
NR 36
TC 332
Z9 401
U1 1
U2 28
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 566
EP 568
DI 10.1038/362566a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300062
PM 8385272
DA 2026-03-10
ER

PT J
AU ROBIN, E
   FROGET, L
   JEHANNO, C
   ROCCHIA, R
AF ROBIN, E
   FROGET, L
   JEHANNO, C
   ROCCHIA, R
TI EVIDENCE FOR A K/T IMPACT EVENT IN THE PACIFIC-OCEAN
SO NATURE
LA English
DT Article
ID cretaceous-tertiary boundary; chemical-composition; sediments; microtektites; mineralogy; iridium; leg-86; debris; key
AB THE chemical, mineralogical and isotopic characteristics of deposits at the Cretaceous/Tertiary (K/T) boundary are suggestive of a large impact event, the prime candidate1 being the Chicxulub crater in Yucatan, Mexico. Spinel-bearing spherules, which may be associated with such impacts, have been reported2 at several K/T boundary sites worldwide, but their origin is still uncertain. We have examined the spinel-bearing material recovered from K/T boundary deposits at site 577 in the Pacific Ocean3 and find two distinct populations of particles: spherules with dendritic spinel textures dispersed throughout the grains and irregularly shaped fragments with spinels essentially confined to the rim. The morphology and composition of the particles are characteristic of melted and partially melted meteoritic ablation debris, but their location is difficult to reconcile with an impact on the Yucatan peninsula, some 10,000 km away. We suggest instead that the spinel-bearing particles at site 577 are derived from the impact of a 2-km asteroid in the Pacific Ocean, and that several accretionary events of this type are required to explain the global distribution of spinel-bearing spherules at the K/T boundary.
RP ROBIN, E (corresponding author), CNRS,CEA,CTR FAIBLES RADIOACT,F-91190 GIF SUR YVETTE,FRANCE.
NR 40
TC 45
Z9 47
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 615
EP 617
DI 10.1038/363615a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900051
DA 2026-03-10
ER

PT J
AU KOHLER, J
   DISSELHORST, JAJM
   DONCKERS, MCJM
   GROENEN, EJJ
   SCHMIDT, J
   MOERNER, WE
AF KOHLER, J
   DISSELHORST, JAJM
   DONCKERS, MCJM
   GROENEN, EJJ
   SCHMIDT, J
   MOERNER, WE
TI MAGNETIC-RESONANCE OF A SINGLE MOLECULAR SPIN
SO NATURE
LA English
DT Article
ID para-terphenyl crystal; fluorescence excitation; pentacene molecules; triplet-state; spectroscopy
AB THE introduction of optical detection methods for observing magnetic resonance transitions in metastable paramagnetic states1-4 has contributed enormously to our understanding of the properties of photoexcited molecules in condensed phases. In such experiments the luminescence intensity is recorded as a function of the frequency of an applied microwave field. At resonance with transitions between sublevels of a metastable paramagnetic state, the lifetime of the metastable state is altered and a consequent change in the luminescence intensity is observed. Here we report the observation of such optically detected magnetic resonance transitions for the triplet state of a single pentacene molecule embedded in a p-terphenyl host crystal. This result has been obtained by combining the conventional optical detection technique for observing magnetic resonance transitions1-4 with the new single-molecule optical detection methods developed recently5,6. This observation opens the way for magnetic resonance studies in condensed phases with single-molecule sensitivity.
C1 LEIDEN UNIV, HUYGENS LAB, CTR STUDY EXCITED STATES MOLECULES, POB 9504, 2300 RA LEIDEN, NETHERLANDS.
   IBM CORP, DIV RES, ALMADEN RES CTR, SAN JOSE, CA 95120 USA.
C3 Leiden University - Excl LUMC; Leiden University; International Business Machines (IBM); IBM USA
NR 10
TC 244
Z9 271
U1 1
U2 54
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 242
EP 244
DI 10.1038/363242a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600044
DA 2026-03-10
ER

PT J
AU PICK, T
   TAUXE, L
AF PICK, T
   TAUXE, L
TI GEOMAGNETIC PALAEOINTENSITIES DURING THE CRETACEOUS NORMAL SUPERCHRON MEASURED USING SUBMARINE BASALTIC GLASS
SO NATURE
LA English
DT Article
ID magnetic-field reversals; polarity reversals; pillow basalts; mantle plumes; paleointensity; paleomagnetism; frequency; geodynamo; intensity; core
AB High-quality palaeointensity data have been obtained from Thellier-Thellier experiments on recent and Cretaceous submarine basaltic glasses. Whereas the recent samples faithfully yield today's geomagnetic intensity at the site, the palaeointensities for the beginning and end of the Cretaceous normal superchron are only 45% and 25%, respectively, of today's value. The data thus extend the 'Mesozoic dipole low' into the Cretaceous superchron, and confirm that submarine basaltic glass is an excellent material for palaeointensity studies.
C1 UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093.
C3 University of California System; University of California San Diego; Scripps Institution of Oceanography
NR 34
TC 137
Z9 142
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 238
EP 242
DI 10.1038/366238a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500054
DA 2026-03-10
ER

PT J
AU FRASER, I
   HUGHES, D
   GORDON, S
AF FRASER, I
   HUGHES, D
   GORDON, S
TI DIVALENT CATION-INDEPENDENT MACROPHAGE ADHESION INHIBITED BY MONOCLONAL-ANTIBODY TO MURINE SCAVENGER RECEPTOR
SO NATURE
LA English
DT Article
ID type-3 complement receptor; rat hybrid myelomas; myelomonocytic cells; human monocyte; proteins; family; lipoproteins; recruitment; integrins; invitro
AB MACROPHAGES interact with other cells and components of the extracellular environment by means of adhesion receptors1,2. Adhesion to artificial substrata in vitro facilitates isolation of macrophages3, and has been used to generate antibodies that inhibit their migration in vivo4,5. Unlike other cell types, macrophages attach to tissue culture plastic in the absence of divalent cations. Here we use an adhesion assay exploiting this property to isolate a rat monoclonal antibody, 2F8, which totally inhibits divalent cation-independent adhesion of murine macrophages to tissue culture plastic in the presence of fetal calf serum. Immunoprecipitation from macrophages and stably transfected Chinese hamster ovary cells revealed that the antigen recognized by monoclonal 2F8 is identical to murine macrophage scavenger receptor6,7. We propose a novel function for this molecule, previously described as an endocytic receptor, thus providing a mechanism for mononuclear phagocyte recruitment to and retention in ligand-rich tissues such as in atherosclerotic lesions.
RP FRASER, I (corresponding author), UNIV OXFORD,SIR WILLIAM DUNN SCH PATHOL,S PARKS RD,OXFORD OX1 3RE,ENGLAND.
NR 23
TC 319
Z9 342
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 343
EP 345
DI 10.1038/364343a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000059
PM 8332192
DA 2026-03-10
ER

PT J
AU SCHALL, JD
   HANES, DP
AF SCHALL, JD
   HANES, DP
TI NEURAL BASIS OF SACCADE TARGET SELECTION IN FRONTAL EYE FIELD DURING VISUAL-SEARCH
SO NATURE
LA English
DT Article
ID rhesus-monkeys; neurons; movements
AB CONSPICUOUS visual features commonly attract gaze1,2, but how the brain selects targets for eye movements is not known. We investigated target selection in rhesus monkeys performing a visual search task3 by recording neurons in the frontal eye field, an area known to be responsible for generating purposive eye movements4,5. Neurons with combined visual- and eye movement-related activity were analysed. We found that the initial visual responses to search stimulus arrays were the same whether the target or a distractor was in the response field. We also found that the neural activity evolved to specify target location before the execution of eye movements, ultimately peaking when the target was in the response field and being suppressed when the target was beside but not distant from the response field. These results demonstrate a possible mechanism by which a desired target is fixated and inappropriate eye movements are prevented.
RP SCHALL, JD (corresponding author), VANDERBILT UNIV,DEPT PSYCHOL,WILSON HALL,NASHVILLE,TN 37240, USA.
NR 16
TC 356
Z9 392
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 467
EP 469
DI 10.1038/366467a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800065
PM 8247155
DA 2026-03-10
ER

PT J
AU ESCARY, JL
   PERREAU, J
   DUMENIL, D
   EZINE, S
   BRULET, P
AF ESCARY, JL
   PERREAU, J
   DUMENIL, D
   EZINE, S
   BRULET, P
TI LEUKEMIA INHIBITORY FACTOR IS NECESSARY FOR MAINTENANCE OF HEMATOPOIETIC STEM-CELLS AND THYMOCYTE STIMULATION
SO NATURE
LA English
DT Article
ID primordial germ-cells; murine; differentiation; survival; invitro
AB LEUKAEMIA inhibitory factor (LIF) has a variety of effects on different cell types in vitro1, inhibiting the differentiation of embryonic stem cells2,3 and promoting the survival and/or proliferation of primitive haematopoietic precursors4,5 and primordial germ cells6,7. Here we show that LIF-deficient mice derived by gene targeting techniques have dramatically decreased numbers of stem cells in spleen and bone marrow. Injection of spleen and marrow cells from these mice promotes long-term survival of lethally irradiated wild-type animals, however, showing that the LIF- stem cells remain pluripotent. The numbers of committed progenitors are also reduced in the spleen but not the bone marrow, suggesting that stem cells interact differently with the splenic and medullary microenvironment. Heterozygous animals are intermediate in phenotype, implying that LIF has a dosage effect, and defects in stem cell number can be compensated by exogenous LIF. LIF thus appears to be required for the survival of the normal pool of stem cells, but not their terminal differentiation.
C1 INST PASTEUR,UNITE EMBRYOL MOLEC,CNRS,URA 1148,F-75724 PARIS 15,FRANCE.
   INST GUSTAVE ROUSSY,INSERM,U362,F-94800 VILLEJUIF,FRANCE.
   CHU NECKER,INSERM,U345,F-75015 PARIS 15,FRANCE.
C3 Centre National de la Recherche Scientifique (CNRS); Pasteur Network; Universite Paris Cite; Institut Pasteur Paris; UNICANCER; Gustave Roussy; Institut National de la Sante et de la Recherche Medicale (Inserm); Institut National de la Sante et de la Recherche Medicale (Inserm); Assistance Publique Hopitaux Paris (APHP); Universite Paris Cite; Hopital Universitaire Necker-Enfants Malades - APHP
NR 24
TC 341
Z9 372
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 361
EP 364
DI 10.1038/363361a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700057
PM 8497320
DA 2026-03-10
ER

PT J
AU EGHOLM, M
   BUCHARDT, O
   CHRISTENSEN, L
   BEHRENS, C
   FREIER, SM
   DRIVER, DA
   BERG, RH
   KIM, SK
   NORDEN, B
   NIELSEN, PE
AF EGHOLM, M
   BUCHARDT, O
   CHRISTENSEN, L
   BEHRENS, C
   FREIER, SM
   DRIVER, DA
   BERG, RH
   KIM, SK
   NORDEN, B
   NIELSEN, PE
TI PNA HYBRIDIZES TO COMPLEMENTARY OLIGONUCLEOTIDES OBEYING THE WATSON-CRICK HYDROGEN-BONDING RULES
SO NATURE
LA English
DT Article
ID peptide nucleic-acids; dna; recognition; replication; antisense; stability; thymine; helices
AB DNA ANALOGUES are currently being intensely investigated owing to their potential as gene-targeted drugs1-3. Furthermore, their properties and interaction with DNA and RNA could provide a better understanding of the structural features of natural DNA that determine its unique chemical, biological and genetic properties3,4. We recently designed a DNA analogue, PNA, in which the backbone is structurally homomorphous with the deoxyribose backbone and consists of N-(2-aminoethyl)glycine units to which the nucleobases are attached5-9. We showed that PNA oligomers containing solely thymine and cytosine can hybridize to complementary oligonucleotides, presumably by forming Watson-Crick-Hoogsteen (PNA)2-DNA triplexes, which are much more stable than the corresponding DNA-DNA duplexes5-7, and bind to double-stranded DNA by strand displacement5,8. We report here that PNA containing all four natural nucleobases hybridizes to complementary oligonucleotides obeying the Watson-Crick base-pairing rules, and thus is a true DNA mimic in terms of base-pair recognition.
C1 PANUM INST,MED BIOTECHNOL RES CTR,DEPT BIOCHEM B,BLEGDAMSVEJ 3C,DK-2200 COPENHAGEN N,DENMARK.
   HC ORSTED INST,DEPT ORGAN CHEM,DK-2100 COPENHAGEN 0,DENMARK.
   ISIS PHARMACEUT,CARLSBAD,CA 92008.
   RISO NATL LAB,DEPT MAT,POLYMER GRP,DK-4000 ROSKILDE,DENMARK.
   CHALMERS UNIV TECHNOL,DEPT PHYS CHEM,S-41296 GOTHENBURG,SWEDEN.
C3 University of Copenhagen; Ionis Pharmaceuticals, Inc.; Technical University of Denmark; Chalmers University of Technology
NR 21
TC 1822
Z9 2620
U1 3
U2 282
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 566
EP 568
DI 10.1038/365566a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100061
PM 7692304
DA 2026-03-10
ER

PT J
AU NOVAKOV, T
   PENNER, JE
AF NOVAKOV, T
   PENNER, JE
TI LARGE CONTRIBUTION OF ORGANIC AEROSOLS TO CLOUD-CONDENSATION-NUCLEI CONCENTRATIONS
SO NATURE
LA English
DT Article
AB THE albedo and radiative properties of marine stratus clouds are determine largely by the number density of cloud condensation nuclei (CCN) over the oceans. Modelling studies have suggested that most of these nuclei are sulphate aerosols derived from both anthropogenic and natural sources1. Here we present evidence that organic aerosols also play a key role in cloud nucleation. We determine the relative contributions of sulphate and organic aerosols to CCN concentrations at a marine site known to be influenced by anthropogenic emissions, and find that organic aerosols account for the major part of both the total aerosol number concentration and the CCN fraction. Thus, in regions that are affected by anthropogenic pollutants, organic aerosols may play at least as important a role as sulphate aerosols in determining the climate effect of clouds.
C1 LAWRENCE LIVERMORE NATL LAB,DIV GLOBAL CLIMATE RES,LIVERMORE,CA 94551.
C3 United States Department of Energy (DOE); Lawrence Livermore National Laboratory
RP NOVAKOV, T (corresponding author), LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,1 CYCLOTRON RD,BERKELEY,CA 94720, USA.
NR 16
TC 622
Z9 715
U1 0
U2 175
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 823
EP 826
DI 10.1038/365823a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100045
DA 2026-03-10
ER

PT J
AU HISATAKE, K
   HASEGAWA, S
   TAKADA, R
   NAKATANI, Y
   HORIKOSHI, M
   ROEDER, RG
AF HISATAKE, K
   HASEGAWA, S
   TAKADA, R
   NAKATANI, Y
   HORIKOSHI, M
   ROEDER, RG
TI THE P250 SUBUNIT OF NATIVE TATA BOX-BINDING FACTOR-TFIID IS THE CELL-CYCLE REGULATORY PROTEIN-CCG1
SO NATURE
LA English
DT Article
ID rna polymerase-ii; transcription factor; preinitiation complex; promoter interactions; activation domain; gene; coactivators; initiation; mechanism; upstream
AB THE protein TFIID is a general transcription factor1 which initiates preinitiation complex assembly2-4 through direct interaction with the TATA promoter element5,6. It is a multisubunit complex containing a small TATA-binding polypeptide (TBP) and other TBP-associated factors (TAFs) ranging in size from about 30-250K (refs 7-10). Although native TFIID can mediate both activator-independent (basal) and activator-dependent transcription in reconstituted systems3,5,6, TBP itself can mediate only basal transcription11,12, even in cases where TBP or the general factor TFIIB are known to interact directly with transcriptional activators13-15. TFIID subunits other than TBP must therefore be essential cofactors, and thus potential targets for activators, consistent with earlier demonstrations that activators interact with TFIID (refs 3, 5, 16, 17). Here we show that the 250K subunit of TFIID is identical to a gene product previously implicated in progression through the late G1 phase of the cell cycle18,19. Part of p250 may thus serve a specific function in the activation of a subset of genes important for cell cycle progression.
C1 NINCDS,MOLEC BIOL LAB,BETHESDA,MD 20892.
C3 National Institutes of Health (NIH) - USA; NIH National Institute of Neurological Disorders & Stroke (NINDS)
RP HISATAKE, K (corresponding author), ROCKEFELLER UNIV,BIOCHEM & MOLEC BIOL LAB,NEW YORK,NY 10021, USA.
NR 30
TC 186
Z9 198
U1 1
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 179
EP 181
DI 10.1038/362179a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800066
PM 8450888
DA 2026-03-10
ER

PT J
AU BRINDLE, P
   LINKE, S
   MONTMINY, M
AF BRINDLE, P
   LINKE, S
   MONTMINY, M
TI PROTEIN-KINASE-A-DEPENDENT ACTIVATOR IN TRANSCRIPTION FACTOR CREB REVEALS NEW ROLE FOR CREM REPRESSORS
SO NATURE
LA English
DT Article
ID mammalian-cells; gene; camp; phosphorylation; expression; promoter
AB HORMONALLY induced increases in cyclic AMP levels induce phosphorylation of the transcription factor CREB at a serine residue at position 133 by protein kinase A (ref. 1), enhancing its ability to activate transcription without affecting its intracellular location or DNA-binding activity. This effect is dependent on a 60-amino-acid region of CREB that contains Ser 133 and is termed the kinase-inducible domain (KID)2, which also occurs in the CREB-related CREM-alpha and -beta proteins, although these are transcriptional repressors3 . Here we show that the KID domain confers a cAMP-inducible increase on the activity of the Q2 activation domain from CREB and the acidic activation domains from the yeast proteins GAL4 and GCN4. Remarkably, it retains this ability even when attached to a separate polypeptide bound to an adjacent site in the promoter. KID may therefore be the first of a new class of conditional activators that work through other promoter-bound factors to stimulate gene expression in response to hormonal stimuli.
RP BRINDLE, P (corresponding author), SALK INST BIOL STUDIES,CLAYTON FDN LABS PEPTIDE BIOL,LA JOLLA,CA 92037, USA.
NR 16
TC 159
Z9 177
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 821
EP 824
DI 10.1038/364821a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100061
PM 8102791
DA 2026-03-10
ER

PT J
AU TOTH, PT
   BINDOKAS, VP
   BLEAKMAN, D
   COLMERS, WF
   MILLER, RJ
AF TOTH, PT
   BINDOKAS, VP
   BLEAKMAN, D
   COLMERS, WF
   MILLER, RJ
TI MECHANISM OF PRESYNAPTIC INHIBITION BY NEUROPEPTIDE-Y AT SYMPATHETIC-NERVE TERMINALS
SO NATURE
LA English
DT Article
ID calcium channels; synaptic functions; neurons; release; modulation; microcultures; norepinephrine; acetylcholine; receptor; cells
AB CALCIUM influx through voltage-sensitive Ca2+ channels is the normal physiological stimulus for the activity-dependent release of neurotransmitters at synaptic contacts. It has been postulated that presynaptic inhibition of transmitter release is due to a reduction in Ca2+ influx at the nerve terminal, which could result from the direct inhibition of Ca2+ channels. Neuropeptide Y and noradrenaline act as cotransmitters at many sympathetic synapses. Both of these substances produce presynaptic inhibition and can inhibit Ca2+ currents in the soma of sympathetic neurons1-5. Here we provide direct evidence that presynaptic inhibition produced by neuropeptide Y at sympathetic nerve terminals is associated with a reduction in Ca2+ influx and that this is due to the selective inhibition of neuronal N-type Ca2+ channels.
C1 UNIV CHICAGO,DEPT PHARMACOL & PHYSIOL SCI,947 E 58TH ST,CHICAGO,IL 60637.
   UNIV ALBERTA,DEPT PHARMACOL,EDMONTON T6G 2H7,ALBERTA,CANADA.
C3 University of Chicago; University of Alberta
NR 25
TC 146
Z9 156
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 635
EP 639
DI 10.1038/364635a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100055
PM 8394510
DA 2026-03-10
ER

PT J
AU ROSENZWEIG, AC
   FREDERICK, CA
   LIPPARD, SJ
   NORDLUND, P
AF ROSENZWEIG, AC
   FREDERICK, CA
   LIPPARD, SJ
   NORDLUND, P
TI CRYSTAL-STRUCTURE OF A BACTERIAL NONHEME IRON HYDROXYLASE THAT CATALYZES THE BIOLOGICAL OXIDATION OF METHANE
SO NATURE
LA English
DT Article
AB The 2.2 angstrom crystal structure of the 251K alpha2beta2gamma2 dimeric hydroxylase protein of methane mono-oxygenase from Methylococcus capsulatus (Bath) reveals the geometry of the catalytic di-iron core. The two iron atoms are bridged by exogenous hydroxide and acetate ligands and further coordinated by four glutamate residues, two histidine residues and a water molecule. The dinuclear iron centre lies in a hydrophobic active-site cavity for binding methane. An extended canyon runs between alphabeta pairs, which have many long alpha-helices, for possible docking of the reductase and coupling proteins required for catalysis.
C1 MIT, DEPT CHEM, CAMBRIDGE, MA 02139 USA.
   HARVARD UNIV, SCH MED, DEPT BIOL CHEM & MOLEC PHARMACOL, BOSTON, MA 02115 USA.
   HARVARD UNIV, SCH MED, DANA FARBER CANC INST, BOSTON, MA 02115 USA.
   UNIV STOCKHOLM, DEPT MOLEC BIOL, S-10691 STOCKHOLM, SWEDEN.
C3 Massachusetts Institute of Technology (MIT); Harvard University; Harvard Medical School; Harvard University; Harvard University Medical Affiliates; Dana-Farber Cancer Institute; Harvard Medical School; Stockholm University
NR 57
TC 884
Z9 978
U1 3
U2 415
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 537
EP 543
DI 10.1038/366537a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800061
PM 8255292
DA 2026-03-10
ER

PT J
AU VIDALE, JE
   BENZ, HM
AF VIDALE, JE
   BENZ, HM
TI SEISMOLOGICAL MAPPING OF FINE-STRUCTURE NEAR THE BASE OF THE EARTHS MANTLE
SO NATURE
LA English
DT Article
ID velocity-structure; lowermost mantle; phase-transitions; high-pressures; thermal state; boundary; convection; iron
AB THE Earth's core-mantle boundary (CMB) juxtaposes liquid iron and crystalline silicates, and is a region of large vertical thermal gradients. The D'' region, which extends up to 200-300 km above the CMB, often has elevated shear-wave velocity and suggestions of lateral variations in structure1. Recent improvements in our ability to assemble and analyse records from regional seismic networks have allowed us to examine long profiles of travel times, amplitudes and waveforms from more than a thousand short-period seismometers2. We observe, across Canada and the United States, P waves that have grazed the CMB from the powerful nuclear test in Lop Nor, China, on 21 May 1992. First-arrival travel times and large secondary arrivals are consistent with a 1.5% compressional velocity increase with depth approximately 130 km above the CMB-about half the thickness of D'' in this locality3. Our observations, together with evidence for the absence of such a thin, fast layer in neighbouring regions, suggest the presence of lateral heterogeneity in composition or phase at the base of the mantle.
RP VIDALE, JE (corresponding author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA.
NR 26
TC 53
Z9 55
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 529
EP 532
DI 10.1038/361529a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400057
DA 2026-03-10
ER

PT J
AU BARLOW, RB
   BIRGE, RR
   KAPLAN, E
   TALLENT, JR
AF BARLOW, RB
   BIRGE, RR
   KAPLAN, E
   TALLENT, JR
TI ON THE MOLECULAR-ORIGIN OF PHOTORECEPTOR NOISE
SO NATURE
LA English
DT Article
ID primary photochemical events; circadian-rhythms; extracellular ph; schiff-base; rhodopsin; retina; toad; performance; sensitivity; system
AB RETINAL photoreceptors are noisy. They generate discrete electrical events in the dark indistinguishable from those evoked by light1,2 and thereby limit visual sensitivity at low levels of illumination3,4. The random spontaneous events are strongly temperature-dependent and have been attributed to thermal isomerizations of the vitamin A chromophore of rhodopsin, the light-sensitive molecule in photoreceptors1,5,6. But thermal generation of dark events in both vertebrate and invertebrate photoreceptors requires activation energies in the range of 23 to 27 kcal mol-1, which are significantly less than the energy barrier of 45 kcal mol-1 for photoisomerization of the chromophore of native rhodopsin7-9. We propose that photoreceptor noise results from the thermal isomerization of a relatively unstable form of rhodopsin, one in which the Schiff-base linkage between the chromophore and protein is unprotonated. This molecular mechanism is supported by both theoretical calculations of the properties of rhodopsin and experimental measurements of the properties of photoreceptor noise.
C1 SYRACUSE UNIV,DEPT BIOENGN & NEUROSCI,SYRACUSE,NY 13244.
   SYRACUSE UNIV,DEPT CHEM,SYRACUSE,NY 13244.
   MARINE BIOL LAB,WOODS HOLE,MA 02543.
C3 Syracuse University; Syracuse University; Marine Biological Laboratory - Woods Hole
RP BARLOW, RB (corresponding author), SYRACUSE UNIV,INST SENSORY RES,SYRACUSE,NY 13244, USA.
NR 32
TC 109
Z9 118
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 64
EP 66
DI 10.1038/366064a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700054
PM 8232538
DA 2026-03-10
ER

PT J
AU ABLE, KP
   ABLE, MA
AF ABLE, KP
   ABLE, MA
TI DAYTIME CALIBRATION OF MAGNETIC ORIENTATION IN A MIGRATORY BIRD REQUIRES A VIEW OF SKYLIGHT POLARIZATION
SO NATURE
LA English
DT Article
ID passerculus-sandwichensis; savannah sparrow; patterns; compass; ontogeny; sunset; information; mechanisms; behavior
AB THE orientation of migratory birds is based on a complex of interacting compass mechanisms (the geomagnetic field, stars, patterns of skylight polarization and, perhaps, the Sun)1,2. A magnetic compass develops in birds that have never seen the sky3-8, but the preferred direction of magnetic orientation may be modified during the first three months of life by exposing naive birds to either the clear daytime or night sky under conditions in which magnetic directions differ substantially from true or geographic directions5-7,9. We hypothesized that celestial rotation, which indicates geographic directions both day and night, served as the calibrating reference7, and showed that a rotating pattern of artificial stars provided a sufficient stimulus to calibrate magnetic orientation in young Savannah sparrows (Passerculus sandwichensis)10. During daytime either the Sun's disc or patterns of polarized skylight could provide the reference to geographic compass directions11-12. Here we report that visual access to natural skylight polarization patterns is necessary for calibration of magnetic orientation during daylight.
RP ABLE, KP (corresponding author), SUNY Albany, DEPT BIOL SCI, ALBANY, NY 12222 USA.
NR 35
TC 89
Z9 99
U1 0
U2 18
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 523
EP 525
DI 10.1038/364523a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700052
DA 2026-03-10
ER

PT J
AU DEAR, SP
   SIMMONS, JA
   FRITZ, J
AF DEAR, SP
   SIMMONS, JA
   FRITZ, J
TI A POSSIBLE NEURONAL BASIS FOR REPRESENTATION OF ACOUSTIC SCENES IN AUDITORY-CORTEX OF THE BIG BROWN BAT
SO NATURE
LA English
DT Article
ID cortical computational maps; target range; echolocating bats; myotis-lucifugus; mustache bat
AB BEHAVIOURAL studies1-4 and field observations5-7 demonstrate that echolocating bats simultaneously perceive range, direction and shape of multiple objects in the environment as acoustic images derived from echoes. Cortical echo delay-tuned neurons contribute to the perception of object range, because focal inactivation of these neurons disrupts behavioural discrimination of range8. We report here that response properties of delay-tuned neurons in the cortical tonotopic area of the bat, Eptesicus, transform the sequential arrival times of echoes with different delays into a concurrent, accumulating neural representation of multiple objects at different ranges. The sharpness of delay tuning systematically increases at each best delay in a subpopulation of these neurons while responses to echoes at different delays are accumulated. The resulting concurrent, multiresolution representation of echo delay corresponds to neural implementation of a common representation of images used in computational vision9-11 and may provide the basis for representing acoustic images of multiple objects as acoustic 'scenes'.
C1 BROWN UNIV,DEPT PSYCHOL,PROVIDENCE,RI 02912.
C3 Brown University
RP DEAR, SP (corresponding author), BROWN UNIV,DEPT NEUROSCI,BOX 1853,PROVIDENCE,RI 02912, USA.
NR 28
TC 94
Z9 103
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 620
EP 623
DI 10.1038/364620a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100051
PM 8350920
DA 2026-03-10
ER

PT J
AU STONE, L
AF STONE, L
TI PERIOD-DOUBLING REVERSALS AND CHAOS IN SIMPLE ECOLOGICAL MODELS
SO NATURE
LA English
DT Article
ID nonoverlapping generations; population-dynamics; complex dynamics; bifurcations; systems; antimonotonicity; multiplicity; behavior
AB The period-doubling route to chaos is a well known feature of a range of simple, nonlinear difference equations routinely used in modelling biological populations. It is not generally understood, however, that the process may easily break down and suddenly reverse, giving rise to distinctive period-halving bifurcations. These reversals may act to control, and possibly prevent, the onset of chaos.
RP STONE, L (corresponding author), TEL AVIV UNIV,FAC LIFE SCI,DEPT ZOOL,IL-69978 TEL AVIV,ISRAEL.
NR 42
TC 193
Z9 203
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 617
EP 620
DI 10.1038/365617a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600048
DA 2026-03-10
ER

PT J
AU MANGEL, WF
   MCGRATH, WJ
   TOLEDO, DL
   ANDERSON, CW
AF MANGEL, WF
   MCGRATH, WJ
   TOLEDO, DL
   ANDERSON, CW
TI VIRAL-DNA AND A VIRAL PEPTIDE CAN ACT AS COFACTORS OF ADENOVIRUS VIRION PROTEINASE ACTIVITY
SO NATURE
LA English
DT Article
ID type-2
AB HUMAN adenovirus (Ad2), like many other viruses1, contains a virion-associated proteinase essential for the synthesis of infectious virus particles2-4. We observed proteinase activity in wild-type virus but not in the ts-1 virus2, which contains a mutation in the Ad2 L3 endoprotease gene5 that confers temperature-sensitive processing of virion precursor proteins. Unexpectedly, we did not observe proteinase activity with purified recombinant6,7 endoprotease protein (M(r) 23 K). Purified recombinant endoprotease protein, however, complemented the mutation in ts-1 virions, restoring proteinase activity when mixed together. This implied that cofactors may be required. Here we reconstitute proteinase activity in vitro with three purified viral components: (1) the recombinant endoprotease protein; (2) an 11-amino-acid peptide that originates from the carboxy terminus of pVI, the precursor to virion component VI; and (3) adenovirus DNA. The use of DNA for a proteinase activity is unprecedented.
RP MANGEL, WF (corresponding author), BROOKHAVEN NATL LAB, DEPT BIOL, UPTON, NY 11973 USA.
NR 11
TC 155
Z9 175
U1 0
U2 9
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 274
EP 275
DI 10.1038/361274a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400065
PM 8423855
DA 2026-03-10
ER

PT J
AU GUICHARD, F
   CAREY, S
   ARTHUR, MA
   SIGURDSSON, H
   ARNOLD, M
AF GUICHARD, F
   CAREY, S
   ARTHUR, MA
   SIGURDSSON, H
   ARNOLD, M
TI TEPHRA FROM THE MINOAN ERUPTION OF SANTORINI IN SEDIMENTS OF THE BLACK-SEA
SO NATURE
LA English
DT Article
ID carbon accumulation rates; sapropel; origin; turkey
AB THE explosive eruption of Santorini volcano in the Aegean Sea about 3,300 years ago is of considerable archaeological and volcanological significance1-5. Here we report the discovery of tephra from this Minoan event in laminated sediments of the Black Sea. This finding provides constraints on the distribution of debris from the eruption. We estimate a minimum fallout area of 2 x 10(6) km2 extending from the Black Sea in the north to the southeastern Mediterranean Sea. The main dispersal axis trends through southern Turkey, in agreement with other studies of Minoan tephra6,7. The tephra deposits should provide a useful reference horizon for assessing the chronology of Black Sea sediments which has been much debated8-15.
C1 UNIV RHODE ISL,GRAD SCH OCEANOG GSO,NARRAGANSETT,RI 02882.
   PENN STATE UNIV,DEPT GEOSCI,UNIV PK,PA 16802.
C3 University of Rhode Island; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park
RP GUICHARD, F (corresponding author), CTR FAIBLES RADIOACT,CNRS,CEA,MIXTE LAB,DOMAINE CNRS,BP 1,F-91198 GIF SUR YVETTE,FRANCE.
NR 34
TC 57
Z9 59
U1 0
U2 14
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 610
EP 612
DI 10.1038/363610a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900049
DA 2026-03-10
ER

PT J
AU RAGOT, T
   VINCENT, N
   CHAFEY, P
   VIGNE, E
   GILGENKRANTZ, H
   COUTON, D
   CARTAUD, J
   BRIAND, P
   KAPLAN, JC
   PERRICAUDET, M
   KAHN, A
AF RAGOT, T
   VINCENT, N
   CHAFEY, P
   VIGNE, E
   GILGENKRANTZ, H
   COUTON, D
   CARTAUD, J
   BRIAND, P
   KAPLAN, JC
   PERRICAUDET, M
   KAHN, A
TI EFFICIENT ADENOVIRUS-MEDIATED TRANSFER OF A HUMAN MINIDYSTROPHIN GENE TO SKELETAL-MUSCLE OF MDX MICE
SO NATURE
LA English
DT Article
ID duchenne muscular-dystrophy; mouse; invivo; expression; injection; dna
AB DUCHENNE progressive muscular dystrophy is a lethal and common X-linked genetic disease1 caused by the absence of dystrophin2,3, a 427K protein encoded by a 14 kilobase transcript4. Two approaches have been proposed to correct the dystrophin deficiency in muscle. The first, myoblast transfer therapy, uses cells from normal donors5-7, whereas the second involves direct intramuscular injection of recombinant plasmids expressing dystrophin8. Adenovirus is an efficient vector for in vivo expression of various foreign genes9-13. It has recently been demonstrated that a recombinant adenovirus expressing the lac-Z reporter gene can infect stably many mouse tissues, particularly muscle and heart12,13. We have tested the ability of a recombinant adenovirus, containing a 6.3 kilobase pair Becker-like dystrophin complementary DNA14 driven by the Rous sarcoma virus promoter to direct the expression of a 'minidystrophin' in infected 293 cells and C2 myoblasts, and in the mdx mouse15,16, after intramuscular injection. We report here that in vivo, we have obtained a sarcolemmal immunostaining in up to 50% of fibres of the injected muscle.
C1 INST COCHIN GENET MOLEC,INSERM,U129,F-75014 PARIS,FRANCE.
   ICGM,INSERM,CJF 9003,F-75014 PARIS,FRANCE.
   INST JACQUES MONOD,CNRS,UMR 3,F-75251 PARIS 05,FRANCE.
C3 Institut National de la Sante et de la Recherche Medicale (Inserm); Universite de Montpellier; Institut National de la Sante et de la Recherche Medicale (Inserm); Centre National de la Recherche Scientifique (CNRS); Universite Paris Cite
RP RAGOT, T (corresponding author), INST GUSTAVE ROUSSY,CNRS,URA 1301,PR2,39 RUE CAMILLE DESMOULINS,F-94805 VILLEJUIF,FRANCE.
NR 28
TC 398
Z9 472
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 647
EP 650
DI 10.1038/361647a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600067
PM 8437625
DA 2026-03-10
ER

PT J
AU ROGERS, BJ
   BRADSHAW, MF
AF ROGERS, BJ
   BRADSHAW, MF
TI VERTICAL DISPARITIES, DIFFERENTIAL PERSPECTIVE AND BINOCULAR STEREOPSIS
SO NATURE
LA English
DT Article
ID stereoscopic depth; perception; distance; model
AB To calculate the depth difference between a pair of points on a three-dimensional surface from binocular disparities, it is necessary to know the absolute distance to the surface1,2. Traditionally, it has been assumed that this information is derived from non-visual sources such as the vergence angle of the eyes3,4. It has been shown 5,6 that the horizontal gradient of vertical disparity between the images in the two eyes also contains information about the fixation distanCe7-9. Recent results10,11, however, indicated that manipulations of the vertical disparity gradient have no effect on either the perceived shape or the perceived depth of surf aces defined by horizontal disparities. Following the reasoning of Longuet-Higgins12 and Tyler13, we suggest that vertical disparities are best understood as a consequence of perspective viewing from two different vantage points and the results we report here show that the human visual system is able to exploit vertical disparities and use them to scale the perceived depth and size of stereoscopic surfaces, if the field of view is sufficiently large.
RP ROGERS, BJ (corresponding author), UNIV OXFORD,DEPT EXPTL PSYCHOL,OXFORD OX1 3UD,ENGLAND.
NR 18
TC 218
Z9 231
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 253
EP 255
DI 10.1038/361253a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400057
PM 8423851
DA 2026-03-10
ER

PT J
AU GLEASON, DF
   WELLINGTON, GM
AF GLEASON, DF
   WELLINGTON, GM
TI ULTRAVIOLET-RADIATION AND CORAL BLEACHING
SO NATURE
LA English
DT Article
AB EPISODES of coral bleaching resulting from dissociation of endosymbiotic algae (zooxanthellae) from host coral tissues have occurred with increasing frequency over the past decade on reefs throughout the tropics1,2. These episodes have usually been attributed to increases in seawater temperatures3-10, but the mass bleaching events that occurred throughout the Caribbean during 1987 and 1990 were not readily explained by temperature alone11,12. An additional factor that may have contributed to these bleaching episodes is ultraviolet radiation in the 280-400-nm band. At many localities where bleaching occurred in 1987 and 1990, sea conditions were described as extremely calm with exceptionally clear water13. In the absence of suspended organic and inorganic matter in the water column, higher than average intensities of ultraviolet radiation probably reached all depths within the photic zone for several consecutive months. Evidence for a possible link between ultraviolet radiation and coral bleaching has not been forthcoming2. Here we report results of a field experiment showing that, irrespective of high water temperatures, short-term (three weeks) increases in ultraviolet radiation of a magnitude possible under calm, clear water column conditions can readily induce bleaching in reef-building corals.
RP GLEASON, DF (corresponding author), UNIV HOUSTON, DEPT BIOL, PROGRAM EVOLUT BIOL & ECOL, HOUSTON, TX 77204 USA.
NR 26
TC 337
Z9 384
U1 0
U2 69
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 836
EP 838
DI 10.1038/365836a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100049
DA 2026-03-10
ER

PT J
AU FINK, JH
   KIEFFER, SW
AF FINK, JH
   KIEFFER, SW
TI ESTIMATE OF PYROCLASTIC FLOW VELOCITIES RESULTING FROM EXPLOSIVE DECOMPRESSION OF LAVA DOMES
SO NATURE
LA English
DT Article
ID emplacement
AB APPARENTLY benign silicic domes or lava flows can travel for several kilometres and then suddenly collapse to generate pyroclastic phenomena capable of causing widespread destruction, as happened recently at Mount Unzen in Japan1. Two sources have been proposed for the energy that propels such 'Pelean' or 'Merapi'-type2 pyroclastic flows: gravitational collapse (supplemented by heating and expansion of air) and sudden expansion of pressurized gases from inside the lava flow. If gravity controls the energy transfer, then areas likely to be affected can be predicted on the basis of topography3, and the resulting deposits will bear a simple relationship to the part of the lava flow from which they issued. But if gas pressure adds a significant contribution, hazard assessment becomes more difficult because gas decompression adds velocities beyond those acquired by gravitational forces, putting much larger areas at risk and forming pyroclastic deposits that are much more difficult to relate to their source. Here we estimate the initial velocities of pyroclastic flows generated by dome disintegration for a range of lava compositions and volatile contents, and offer a conceptual framework for correlating the dynamics of dome-front collapse with the resulting sediment record. Our results indicate that explosive decompression at distal portions of domes can cause velocities comparable to gravitational collapse, especially in cases where volatiles become locally concentrated above equilibrium values.
RP FINK, JH (corresponding author), ARIZONA STATE UNIV,DEPT GEOL,TEMPE,AZ 85287, USA.
NR 29
TC 73
Z9 75
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 612
EP 615
DI 10.1038/363612a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900050
DA 2026-03-10
ER

PT J
AU SHEMANSKY, DE
   MATHESON, P
   HALL, DT
   HU, HY
   TRIPP, TM
AF SHEMANSKY, DE
   MATHESON, P
   HALL, DT
   HU, HY
   TRIPP, TM
TI DETECTION OF THE HYDROXYL RADICAL IN THE SATURN MAGNETOSPHERE
SO NATURE
LA English
DT Article
ID neutral cloud; plasma torus; model
AB THE magnetosphere in the vicinity of the orbits of Saturn's icy satellites consists of a low-density plasma, in which the electrons are an order of magnitude cooler than the accompanying heavy ions1.  Most models2-12 neglect this fact, even though radiative cooling and diffusive loss rates are both too slow to account for the observed temperatures. Shemansky and Hall13 have recently proposed that the electrons could be cooled by the presence of a large abundance of neutral gas, derived mainly from the breakdown products of H2O (mainly O and OH) from the icy satellites. Hydrogen radicals have been reported in this region13, but these originate from the atmosphere of Saturn itself; no satellite-derived neutral species have been detected. Here we report the detection of neutral OH molecules near the orbit of Tethys, using the Faint Object Spectrograph on the Hubble Space Telescope. Our results suggest that neutral OH is one of the dominant species in Saturn's inner magnetosphere, implying a source rate for H2O twenty times greater than current theoretical estimates5,6. One possible explanation is that the micrometeorite erosion rates of the inner satellites are significantly higher than expected.
C1 JOHNS HOPKINS UNIV,DEPT PHYS,BALTIMORE,MD 21218.
   UNIV WISCONSIN,DEPT ASTRON,MADISON,WI 53706.
C3 Johns Hopkins University; University of Wisconsin System; University of Wisconsin Madison
RP SHEMANSKY, DE (corresponding author), UNIV SO CALIF,DEPT AEROSP ENGN,LOS ANGELES,CA 90089, USA.
NR 21
TC 143
Z9 153
U1 1
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 329
EP 331
DI 10.1038/363329a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700045
DA 2026-03-10
ER

PT J
AU LEYSER, HMO
   LINCOLN, CA
   TIMPTE, C
   LAMMER, D
   TURNER, J
   ESTELLE, M
AF LEYSER, HMO
   LINCOLN, CA
   TIMPTE, C
   LAMMER, D
   TURNER, J
   ESTELLE, M
TI ARABIDOPSIS AUXIN-RESISTANCE GENE-AXR1 ENCODES A PROTEIN RELATED TO UBIQUITIN-ACTIVATING ENZYME-E1
SO NATURE
LA English
DT Article
ID thaliana; sequence; gene; transformation; expression; mutants; cloning; linkage
AB THE plant hormone auxin has a central role in many aspects of plant growth and development1,2. By screening for mutants of Arabidopsis that are resistant to exogenous auxin, we have identified several genes that are required for normal auxin response3. One of these genes, AXR1, is defined by recessive mutations that confer auxin resistance to the roots, rosettes and inflorescences of mutant plants4-6. In addition, axr1 mutants display a variety of morphological defects that are consistent with a reduction in auxin sensitivity5. Here we isolate the AXR1 gene using a map-based approach and report that AXR1 encodes a new protein with significant sequence similarity to the ubiquitin-activating enzyme E1. The AXR1 protein is highly diverged from previously characterized E1 enzymes, however, and lacks a key cysteine residue that is essential for E1 activity7. AXR1 may therefore define a new class of enzymes in the ubiquitin pathway or it may have a novel function in cellular regulation which is unrelated to ubiquitin conjugation.
C1 INDIANA UNIV,DEPT BIOL,BLOOMINGTON,IN 47405.
C3 Indiana University System; Indiana University Bloomington
NR 25
TC 423
Z9 481
U1 2
U2 55
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 161
EP 164
DI 10.1038/364161a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700054
PM 8321287
DA 2026-03-10
ER

PT J
AU LASKAR, J
   ROBUTEL, P
AF LASKAR, J
   ROBUTEL, P
TI THE CHAOTIC OBLIQUITY OF THE PLANETS
SO NATURE
LA English
DT Article
ID solar-system; mars; evolution; rotation; motion
AB Numerical study of the global stability of the spin-axis orientation (obliquity) of the planets against secular orbital perturbations shows that all of the terrestrial planets could have experienced large, chaotic variations in obliquity at some time in the past. The obliquity of Mars is still in a large chaotic region, ranging from 0-degrees to 60-degrees. Mercury and Venus have been stabilized by tidal dissipation, and the Earth may have been stabilized by capture of the Moon. None of the obliquities of the terrestrial planets can therefore be considered as primordial.
RP LASKAR, J (corresponding author), BUR LONGITUDES,77 AVE DENFERT ROCHEREAU,F-75014 PARIS,FRANCE.
NR 32
TC 415
Z9 454
U1 0
U2 49
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 608
EP 612
DI 10.1038/361608a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600054
DA 2026-03-10
ER

PT J
AU TAYLOR, KC
   HAMMER, CU
   ALLEY, RB
   CLAUSEN, HB
   DAHLJENSEN, D
   GOW, AJ
   GUNDESTRUP, NS
   KIPFSTUHL, J
   MOORE, JC
   WADDINGTON, ED
AF TAYLOR, KC
   HAMMER, CU
   ALLEY, RB
   CLAUSEN, HB
   DAHLJENSEN, D
   GOW, AJ
   GUNDESTRUP, NS
   KIPFSTUHL, J
   MOORE, JC
   WADDINGTON, ED
TI ELECTRICAL-CONDUCTIVITY MEASUREMENTS FROM THE GISP2 AND GRIP GREENLAND ICE CORES
SO NATURE
LA English
DT Article
AB THE direct-current electrical conductivity of glacial ice depends on its acidity1-3, and can also indicate changes in climate, as ice formed in cold, dusty periods has a high concentration of alkaline dust1,4,5, which significantly reduces the conductivity6,7 compared to warmer, less dusty periods. Here we present electrical conductivity records for the Greenland Ice Sheet Project 2 (GISP2) and Greenland Ice-core Project (GRIP) ice cores, drilled 28 km apart to enable direct comparison of the results. The upper parts of both records are consistent with previous evidence from other Greenland cores4,8-12 for a stable Greenland climate during the Holocene, and a series of warm events punctuating the last glacial period. However, there is a significant discrepancy between the two records in the bottom 10% of the cores, calling into question recent reports of climate variability in the last interglacial4,8 and the penultimate glaciation8. At this stage, it is too early to say what exactly is causing the discrepancy, although ice flow may have introduced some discontinuities into the records. Further work will be necessary to establish how much climatic information it will eventually be possible to extract from the lower parts of the two cores.
C1 UNIV COPENHAGEN, NIELS BOHR INST ASTROM PHYS & GEOPHYS, DEPT GEOPHYS, DK-2200 COPENHAGEN, DENMARK.
   PENN STATE UNIV, CTR EARTH SYST SCI, UNIV PK, PA 16802 USA.
   PENN STATE UNIV, DEPT GEOSCI, UNIV PK, PA 16802 USA.
   COLD REG RES LAB, HANOVER, NH 03755 USA.
   ALFRED WEGENER INST POLAR & MARINE RES, D-27568 BRENERHAVEN, GERMANY.
   UNIV LAPLAND, ARCTIC CTR, SF-96101 ROVANIEMI, FINLAND.
   BRITISH ANTARCTIC SURVEY, CAMBRIDGE CB3 0ET, ENGLAND.
   UNIV WASHINGTON, GEOPHYS PROGRAM AK50, SEATTLE, WA 98195 USA.
C3 University of Copenhagen; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; United States Department of Defense; United States Army; U.S. Army Corps of Engineers; U.S. Army Engineer Research & Development Center (ERDC); Cold Regions Research & Engineering Laboratory (CRREL); Helmholtz Association; Alfred Wegener Institute, Helmholtz Centre for Polar & Marine Research; University of Lapland; UK Research & Innovation (UKRI); Natural Environment Research Council (NERC); NERC British Antarctic Survey; University of Washington; University of Washington Seattle
RP TAYLOR, KC (corresponding author), UNIV NEVADA, DESERT RES INST, BOX 60220, RENO, NV 89506 USA.
NR 36
TC 190
Z9 210
U1 1
U2 25
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 549
EP 552
DI 10.1038/366549a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800064
DA 2026-03-10
ER

PT J
AU NOMOTO, K
   SUZUKI, T
   SHIGEYAMA, T
   KUMAGAI, S
   YAMAOKA, H
   SAIO, H
AF NOMOTO, K
   SUZUKI, T
   SHIGEYAMA, T
   KUMAGAI, S
   YAMAOKA, H
   SAIO, H
TI A TYPE-IIB MODEL FOR SUPERNOVA-1993J
SO NATURE
LA English
DT Article
ID helium star models; light curves; ib supernovae; explosions
AB SPECTRAL, analyses of supernovae have allowed them to be broadly divided into two classes, type I and type II. Supernova 1993J was identified1-3 as a type II supernova following the detection of a weak hydrogen line in its early spectrum. But the optical light curve' of SN1993J is atypical for this class of supernova, with the intensity rising to a second maximum after the initial outburst. The light curve around the second maximum more closely resembles that of the type Ib supernova 1983N (ref. 5), the progenitor of which may have been a helium star6. Here we show that the secondary brightening and subsequent decay of the light curve can be explained by the radioactive decay of Co-56; combined with the early spectrum, this suggests that the progenitor may have been a red supergiant with an unusually thin hydrogen-rich envelope. If this model is correct, the spectrum will rapidly evolve from type II to type Ib, in which case SN1993J would be classified as a type IIb supernova7,8. We Suggest that the progenitor was in a binary system, and had lost most of its hydrogen envelope to the companion star before the explosion.
C1 KYUSHU UNIV, COLL GEN EDUC, DEPT PHYS, FUKUOKA 810, JAPAN.
   TOHOKU UNIV, FAC SCI, DEPT ASTRON, SENDAI, MIYAGI 980, JAPAN.
C3 Kyushu University; Tohoku University
RP NOMOTO, K (corresponding author), UNIV TOKYO, SCH SCI, DEPT ASTRON, TOKYO 113, JAPAN.
NR 29
TC 225
Z9 238
U1 0
U2 3
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 507
EP 509
DI 10.1038/364507a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700045
DA 2026-03-10
ER

PT J
AU HAYGOOD, MG
   DISTEL, DL
AF HAYGOOD, MG
   DISTEL, DL
TI BIOLUMINESCENT SYMBIONTS OF FLASHLIGHT FISHES AND DEEP-SEA ANGLERFISHES FORM UNIQUE LINEAGES RELATED TO THE GENUS VIBRIO
SO NATURE
LA English
DT Article
ID 16s ribosomal-rna; luminous bacteria; kryptophanaron-alfredi; evolution; anomalopidae; phylogeny; seawater; genes
AB BIOLUMINESCENT symbioses range from facultative associations to highly adapted. apparently obligate ones1. The family Anomalopidae (flashlight fishes) encompasses five genera of tropical reef fishes that have large suborbital light organs2. The suborder Ceratioidei (deep-sea anglerfishes) contains 11 families. In nine of these, females have a bioluminescent lure3,4 that contains bacterial symbionts5. In all other fish light-organ symbioses (occuring in 10 families in 5 orders6), the symbionts belong to three Photobacterium species7; nonsymbiotic luminous bacteria are Vibrio species8. The bacteria are extracellular and tightly packed in tubules that communicate with the exterior7, releasing bacteria into the gut of the host or the surrounding sea water. The released bacteria are usually cultivable and can contribute to planktonic populations9,10. Although anomalopids release bacteria9 and ceratioids have pores that would allow release, the fate of these bacteria is unknown and they cannot be cultured by standard isolation techniques. We report here phylogenetic analysis of 16S ribosomal RNA gene sequences from light organs that show that anomalopid and ceratioid symbionts are not known luminous bacteria, but are new groups related to Vibrio spp. They are characterized by host specificity, deep divergence between symbionts from different genera (anomalopids) or families (ceratioids) and, possibly, parallel divergence of hosts and symbionts.
RP HAYGOOD, MG (corresponding author), UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, DIV MARINE BIOL RES, 0202, LA JOLLA, CA 92093 USA.
NR 28
TC 68
Z9 75
U1 0
U2 69
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 154
EP 156
DI 10.1038/363154a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100045
PM 7683390
DA 2026-03-10
ER

PT J
AU BROWN, JH
   JARDETZKY, TS
   GORGA, JC
   STERN, LJ
   URBAN, RG
   STROMINGER, JL
   WILEY, DC
AF BROWN, JH
   JARDETZKY, TS
   GORGA, JC
   STERN, LJ
   URBAN, RG
   STROMINGER, JL
   WILEY, DC
TI 3-DIMENSIONAL STRUCTURE OF THE HUMAN CLASS-II HISTOCOMPATIBILITY ANTIGEN HLA-DR1
SO NATURE
LA English
DT Article
ID mhc class-ii; nonobese diabetic mice; t-cell recognition; hla-dr; crystallographic refinement; surface expression; peptide antigens; molecular-basis; binding site; beta-chain
AB The three-dimensional structure of the class II histocompatibility glycoprotein HLA-DR1 from human B-cell membranes has been determined by X-ray crystallography and is similar to that of class I HLA. Peptides are bound in an extended conformation that projects from both ends of an 'open-ended' antigen-binding groove. A prominent non-polar pocket into which an 'anchoring' peptide side chain fits is near one end of the binding groove. A dimer of the class II alphabeta heterodimers is seen in the crystal forms of HLA-DR1, suggesting class II HLA dimerization as a mechanism for initiating the cytoplasmic signalling events in T-cell activation.
C1 HARVARD UNIV, DEPT BIOCHEM & MOLEC BIOL, 7 DIVIN AVE, CAMBRIDGE, MA 02138 USA.
   CHILDRENS HOSP PITTSBURGH, DEPT PEDIAT, PITTSBURGH, PA 15213 USA.
   HARVARD UNIV, HOWARD HUGHES MED INST, CAMBRIDGE, MA 02138 USA.
C3 Harvard University; Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh; Harvard University; Howard Hughes Medical Institute
NR 69
TC 2195
Z9 2399
U1 0
U2 83
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 33
EP 39
DI 10.1038/364033a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800048
PM 8316295
DA 2026-03-10
ER

PT J
AU WOODHEAD, JD
   GREENWOOD, P
   HARMON, RS
   STOFFERS, P
AF WOODHEAD, JD
   GREENWOOD, P
   HARMON, RS
   STOFFERS, P
TI OXYGEN ISOTOPE EVIDENCE FOR RECYCLED CRUST IN THE SOURCE OF EM-TYPE OCEAN ISLAND BASALTS
SO NATURE
LA English
DT Article
ID mantle plumes; geochemistry; element; sr; genesis; lavas; rocks; arcs; nd
AB The oxygen isotope compositions of fresh volcanic glasses from submarine volcanoes of 'enriched mantle' (EM-I and EM-II) type appear to require the presence of subducted crustal components in the source of these lavas. These data confirm earlier inferences from trace elements and radiogenic isotopes, and also provide a rare opportunity to estimate the proportion of subducted material that reaches the source region of ocean island basalts.
C1 KINGSLEY DUNHAM CTR,NERC,ISOTOPE GEOSCI LAB,KEYWORTH NG12 5GG,NOTTS,ENGLAND.
   UNIV KIEL,INST GEOL,W-2300 KIEL 1,GERMANY.
C3 UK Research & Innovation (UKRI); Natural Environment Research Council (NERC); NERC British Geological Survey; University of Kiel
RP WOODHEAD, JD (corresponding author), AUSTRALIAN NATL UNIV,RES SCH EARTH SCI,CANBERRA,ACT 0200,AUSTRALIA.
NR 29
TC 81
Z9 86
U1 0
U2 19
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 809
EP 813
DI 10.1038/362809a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300046
DA 2026-03-10
ER

PT J
AU TROMP, J
AF TROMP, J
TI SUPPORT FOR ANISOTROPY OF THE EARTHS INNER-CORE FROM FREE OSCILLATIONS
SO NATURE
LA English
DT Article
ID differential travel-times; period normal-modes; aspherical structure; pkikp; multiplets; iron
AB IN 1983, Poupinet et al.1 observed that compressional seismic waves traversing the inner core along a trajectory parallel to the Earth's rotation axis arrive faster than the same (PKIKP) waves travelling in the equatorial plane. They interpreted this observation as revealing prolate topography of the inner-core boundary. In 1986, Morelli et al.2 and Woodhouse et al.3 suggested that inner-core anisotropy could explain both the travel-time observations and the anomalous splitting of some of the Earth's normal modes. Inner-core anisotropy continues to be the preferred explanation for the travel-time anomalies, although there is disagreement about the magnitude of anisotropy4-6. More recent explanations for the anomalous splitting involve topography of the inner-core and core7-11. mantle boundaries as well as lateral heterogeneity of the core In particular, Widmer et al.11 dismissed a rather complex recent model of inner-core anisotropy12 because it could not explain the splitting of several previously unidentified modes. Here I show that the anomalous splitting of all currently identified modes can in fact be explained by cylindrical anisotropy of the Earth's inner core that is also compatible with the observed PKIKP travel-time anomalies. The resulting model should be regarded as an upper limit to the amount of anisotropy, as lateral heterogeneity also undoubtedly contributes to the splitting.
RP TROMP, J (corresponding author), HARVARD UNIV,DEPT EARTH & PLANETARY SCI,CAMBRIDGE,MA 02138, USA.
NR 21
TC 168
Z9 185
U1 0
U2 18
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 678
EP 681
DI 10.1038/366678a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500067
DA 2026-03-10
ER

PT J
AU BETHUNE, DS
   KIANG, CH
   DEVRIES, MS
   GORMAN, G
   SAVOY, R
   VAZQUEZ, J
   BEYERS, R
AF BETHUNE, DS
   KIANG, CH
   DEVRIES, MS
   GORMAN, G
   SAVOY, R
   VAZQUEZ, J
   BEYERS, R
TI COBALT-CATALYZED GROWTH OF CARBON NANOTUBES WITH SINGLE-ATOMIC-LAYERWALLS
SO NATURE
LA English
DT Article
ID c-60; filaments
AB CARBON exhibits a unique ability to form a wide range of structures. In an inert atmosphere it condenses to form hollow, spheroidal fullerenes1-4. Carbon deposited on the hot tip of the cathode of the arc-discharge apparatus used for bulk fullerene synthesis will form nested graphitic tubes and polyhedral particles5-8. Electron irradiation of these nanotubes and polyhedra transforms them into nearly spherical carbon 'onions'9. We now report that covaporizing carbon and cobalt in an arc generator leads to the formation of carbon nanotubes which all have very small diameters (about 1.2 nm) and walls only a single atomic layer thick. The tubes form a web-like deposit woven through the fullerene-containing soot, giving it a rubbery texture. The uniformity and single-layer structure of these nanotubes should make it possible to test their properties against theoretical predictions10-13.
C1 CALTECH,BECKMAN INST,CTR MAT & MOLEC SIMULAT,PASADENA,CA 91125.
C3 California Institute of Technology
RP BETHUNE, DS (corresponding author), IBM CORP,DIV RES,ALMADEN RES CTR,650 HARRY RD,SAN JOSE,CA 95120, USA.
NR 22
TC 3391
Z9 4102
U1 10
U2 832
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 605
EP 607
DI 10.1038/363605a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900047
DA 2026-03-10
ER

PT J
AU EISELE, JL
   BERTRAND, S
   GALZI, JL
   DEVILLERSTHIERY, A
   CHANGEUX, JP
   BERTRAND, D
AF EISELE, JL
   BERTRAND, S
   GALZI, JL
   DEVILLERSTHIERY, A
   CHANGEUX, JP
   BERTRAND, D
TI CHIMERIC NICOTINIC SEROTONERGIC RECEPTOR COMBINES DISTINCT LIGAND-BINDING AND CHANNEL SPECIFICITIES
SO NATURE
LA English
DT Article
ID gated ion channel; marmorata acetylcholine-receptor; alpha-subunit; delta-subunit; xenopus oocytes; 5-hydroxytryptamine; expression; sequences; calcium; neurons
AB THE neuronal nicotinic alpha7 (nAChR) and 5-hydroxytryptamine (5HT3) receptors1-3 are ligand-gated ion channels with a homologous topological organization and have activation and desensitization reactions in common. Yet these homo-oligomeric receptors differ in the pharmacology of their binding sites for agonists and competitive antagonists3,4, and in their sensitivity to Ca2+ ions. The alpha7 channel is highly permeable to Ca2+ ions5,6 and external Ca2+ ions potentiate, in an allosteric manner, the permeability response to acetylcholine, as shown for other neuronal nAChRs7,8. The 5HT3 channel, in contrast, is not permeable to Ca2+ ions, but blocked by them3,9. To assign these properties to delimited domains of the primary structure, we constructed several recombinant chimaeric alpha7-5HT3 receptors. We report here that one of the constructs expresses a functional receptor that contains the serotonergic channel still blocked by Ca2+ ions, but is activated by nicotinic ligands and potentiated by external Ca2+ ions.
C1 UNIV GENEVA, MED CTR, FAC MED, DEPT PHYSIOL, CH-1211 GENEVA 4, SWITZERLAND.
C3 University of Geneva
RP EISELE, JL (corresponding author), INST PASTEUR, CNRS, UNITE NEUROBIOL MOLEC D1284, 25 RUE DR ROUX, F-75724 PARIS 15, FRANCE.
NR 35
TC 359
Z9 412
U1 0
U2 15
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 479
EP 483
DI 10.1038/366479a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800069
PM 8247158
DA 2026-03-10
ER

PT J
AU JACENKO, O
   LUVALLE, PA
   OLSEN, BR
AF JACENKO, O
   LUVALLE, PA
   OLSEN, BR
TI SPONDYLOMETAPHYSEAL DYSPLASIA IN MICE CARRYING A DOMINANT-NEGATIVE MUTATION IN A MATRIX PROTEIN-SPECIFIC FOR CARTILAGE-TO-BONE TRANSITION
SO NATURE
LA English
DT Article
ID x collagen gene; regions; domain; viii
AB THE vertebrate skeleton is formed primarily by endochondral ossification, starting during embryogenesis when cartilage anlagens develop central regions of hypertrophic cartilage which are replaced by bony trabeculae and bone marrow1,2. During this process chondrocytes express a unique matrix molecule, type X collagen3. We report here that mice carrying a mutated collagen X transgene develop skeletal deformities including compression of hypertrophic growth plate cartilage and a decrease in newly formed bone, as well as leukocyte deficiency in bone marrow, reduction in size of thymus and spleen, and lymphopenia. The defects indicate that collagen X is required for normal skeletal morphogenesis and suggest that mutations in COL10A1 are responsible for certain human chondrodysplasias, such as spondylometaphyseal dysplasias and metaphyseal chondrodysplasias4.
RP JACENKO, O (corresponding author), HARVARD UNIV, SCH MED, DEPT ANAT & CELLULAR BIOL, 220 LONGWOOD AVE, BOSTON, MA 02115 USA.
NR 20
TC 184
Z9 194
U1 0
U2 6
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 56
EP 61
DI 10.1038/365056a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600053
PM 8361538
DA 2026-03-10
ER

PT J
AU KOPF, M
   LEGROS, G
   BACHMANN, M
   LAMERS, MC
   BLUETHMANN, H
   KOHLER, G
AF KOPF, M
   LEGROS, G
   BACHMANN, M
   LAMERS, MC
   BLUETHMANN, H
   KOHLER, G
TI DISRUPTION OF THE MURINE IL-4 GENE BLOCKS TH2 CYTOKINE RESPONSES
SO NATURE
LA English
DT Article
ID stimulatory factor-i; cd4+ t-cells; monoclonal-antibody; ige responses; growth-factor; lymphocyte-t; stem-cells; invivo; clones; mice
AB MURINE T-helper clones are classified into two distinct subsets (Th1 and Th2) on the basis of their patterns of lymphokine secretion. Th1 clones secrete interleukin-2 (IL-2), tumour necrosis factor-beta (TNF-beta) and interferon-gamma (IFN-gamma), whereas Th2 clones secrete IL-4, IL-5 and IL-10 (ref. 1). These subsets are reciprocally regulated by IL-4, IL-10 and IFN-gamma and differentially promote antibody or delayed-type hypersensitivity responses2,3. To evaluate whether IL-4 is required for mounting Th2 responses, we generated IL-4-mutant mice (IL4-/-)4,5 and assessed the cytokine secretion pattern of T cells both from naive and Nippostrongylus brasiliensis infected mice. CD4+ T cells from naive IL-4-/- mice failed to produce Th2-derived cytokines after in vitro stimulation. The levels of Th2 cytokines IL-5, IL-9 and IL-10 from CD4+ T cells obtained after nematode infection were significantly reduced. The reduced IL-5 production in IL-4-/- mice correlated with reduced helminth-induced eosinophilia, which has been shown to be dependent on IL-5 in vivo6. We conclude that IL4 is required for the generation of the Th2-derived cytokines and that immune responses dependent on these cytokines are impaired.
C1 CIBA GEIGY AG,CH-4002 BASEL,SWITZERLAND.
   UNIV ZURICH,INST EXPTL IMMUNOL,CH-8006 ZURICH,SWITZERLAND.
   F HOFFMANN LA ROCHE & CO LTD,CH-4002 BASEL,SWITZERLAND.
C3 Novartis; University of Zurich; Roche Holding
RP KOPF, M (corresponding author), MAX PLANCK INST IMMUNBIOL,W-7800 FREIBURG,GERMANY.
NR 30
TC 1151
Z9 1292
U1 2
U2 38
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 245
EP 248
DI 10.1038/362245a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600056
PM 8384701
DA 2026-03-10
ER

PT J
AU LOWELL, BB
   SSUSULIC, V
   HAMANN, A
   LAWITTS, JA
   HIMMSHAGEN, J
   BOYER, BB
   KOZAK, LP
   FLIER, JS
AF LOWELL, BB
   SSUSULIC, V
   HAMANN, A
   LAWITTS, JA
   HIMMSHAGEN, J
   BOYER, BB
   KOZAK, LP
   FLIER, JS
TI DEVELOPMENT OF OBESITY IN TRANSGENIC MICE AFTER GENETIC ABLATION OF BROWN ADIPOSE-TISSUE
SO NATURE
LA English
DT Article
ID mitochondrial uncoupling protein; cold-acclimated rats; toxin-a-chain; molecular-cloning; beta-3-adrenergic receptor; induced thermogenesis; blood-flow; expression; fat; animals
AB BROWN adipose tissue, because of its capacity for uncoupled mitochondrial respiration 1,2, has been implicated as an important site of facultative energy expenditure3-5. This has led to speculation that this tissue normally functions to prevent obesity3-5. Attempts to ablate or denervate brown adipose tissue surgically have been uninformative because it exists in diffuse depots and has substantial capacity for regeneration and hypertrophy6. Here we have used a transgenic toxigene approach7,8 to create two lines of transgenic mice with primary deficiency of brown adipose tissue. At 16 days, both lines have decreased brown fat and obesity, In one line, brown fat subsequently regenerates and obesity resolves. In the other line, the deficiency persists and obesity, with its morbid complications, advances. Obesity develops in the absence of hyperphagia, indicating that brown fat deficient mice have increased metabolic efficiency. As obesity progresses, transgenic animals develop hyperphagia. This study supports a critical role for brown adipose tissue in the nutritional homeostasis of mice.
C1 BETH ISRAEL HOSP,HARVARD THORNDIKE LAB,DEPT MED,BOSTON,MA 02215.
   BETH ISRAEL HOSP,DEPT PATHOL,BOSTON,MA 02215.
   HARVARD UNIV,SCH MED,BOSTON,MA 02115.
   UNIV OTTAWA,FAC MED,DEPT BIOCHEM,OTTAWA K1H 8M5,ONTARIO,CANADA.
   JACKSON LAB,BAR HARBOR,ME 04609.
C3 Harvard University; Harvard University Medical Affiliates; Beth Israel Deaconess Medical Center; Harvard University; Harvard University Medical Affiliates; Beth Israel Deaconess Medical Center; Harvard University; Harvard Medical School; University of Ottawa; Jackson Laboratory
RP LOWELL, BB (corresponding author), CHARLES A DANA RES INST,BOSTON,MA 02215, USA.
NR 29
TC 932
Z9 1054
U1 0
U2 64
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 23
PY 1993
VL 366
IS 6457
BP 740
EP 742
DI 10.1038/366740a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MN264
UT WOS:A1993MN26400027
PM 8264795
DA 2026-03-10
ER

PT J
AU BENZ, HM
   VIDALE, JE
AF BENZ, HM
   VIDALE, JE
TI SHARPNESS OF UPPER-MANTLE DISCONTINUITIES DETERMINED FROM HIGH-FREQUENCY REFLECTIONS
SO NATURE
LA English
DT Article
ID system mg2sio4-fe2sio4; transition zone; 520-km discontinuity; 670-km discontinuity; spinel transitions; p'p'; olivine; constraints; precursors; beneath
AB AN understanding of the nature of seismic discontinuities in the Earth's upper mantle is important for understanding mantle processes: in particular, the amplitude and sharpness of these discontinuities are critical for assessing models of upper-mantle phase changes and chemical layering. So far, seismic studies aimed at determining the thickness and lateral variability of upper-mantle discontinuities have yielded equivocal results, particularly for the discontinuity at 410 km depth1,2. Here we present short-period (0.8-2.0 s) recordings of upper-mantle precursors to the seismic phase P'P' (PKPPKP) from two South American earthquakes recorded by the approximately 700-station short-period array in California. Our results show that the 410- and 660-km discontinuities beneath the Indian Ocean are locally simple and sharp, corresponding to transition zones of 4 km or less. These observations pose problems for mineral physics models3-5, which predict a transitional thickness greater than 6 km for the peridotite to beta-spinel phase transition. In contrast to the results of long-period studies6,7, we observe no short-period arrivals from near 520 km depth.
C1 US GEOL SURVEY,MENLO PK,CA 94025.
C3 United States Department of the Interior; United States Geological Survey
RP BENZ, HM (corresponding author), US GEOL SURVEY,GOLDEN,CO 80401, USA.
NR 31
TC 177
Z9 198
U1 0
U2 17
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 147
EP 150
DI 10.1038/365147a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200044
DA 2026-03-10
ER

PT J
AU JIA, ZC
   VANDONSELAAR, M
   QUAIL, JW
   DELBAERE, LTJ
AF JIA, ZC
   VANDONSELAAR, M
   QUAIL, JW
   DELBAERE, LTJ
TI ACTIVE-CENTER TORSION-ANGLE STRAIN REVEALED IN 1.6 ANGSTROM-RESOLUTION STRUCTURE OF HISTIDINE-CONTAINING PHOSPHOCARRIER PROTEIN
SO NATURE
LA English
DT Article
ID escherichia-coli; macromolecular crystallography; phosphotransferase system; tertiary structure; hpr; h-1-nmr; phosphoenolpyruvate; assignments; resonance; secondary
AB THE histidine-containing phosphocarrier protein (HPr) is a central component of the phosphoenolpyruvate: sugar phosphotransferase system that transports carbohydrates across the cell membrane of bacteria1. A typical phosphotransfer sequence is phosphoenolpyruvate --> enzyme I --> HPr --> enzyme II/III(sugar) -->. This is thermodynamically favourable owing to the participation of the high-energy phosphoenolpyruvate. We report here the structure of HPr from Streptococcus faecalis determined at 1.6 angstrom resolution. Remarkable disallowed Ramachandran torsion angles at the active centre, revealed by the X-ray structure, demonstrate a unique example of torsion-angle strain that is probably directly involved in protein function. During phosphorylation, the active-centre torsion-angle strain should facilitate the phosphotransfer reaction by lowering the activation-energy barrier. A recently reported Bacillus subtilis HPr structure2, which represents the phosphorylated state of HPr with no torsion-angle strain, provides direct evidence supporting our hypothesis that torsion-angle strain plays a direct part in the function of HPr. An HPr phosphotransfer cycling mechanism is proposed, based primarily on the structures of HPr and other phosphotransferase system proteins.
C1 UNIV SASKATCHEWAN,DEPT BIOCHEM,SASKATOON S7N 0W0,SASKATCHEWAN,CANADA.
C3 University of Saskatchewan
RP JIA, ZC (corresponding author), UNIV SASKATCHEWAN,DEPT CHEM,SASKATOON S7N 0W0,SASKATCHEWAN,CANADA.
NR 25
TC 63
Z9 67
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 94
EP 97
DI 10.1038/361094a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800058
PM 8421502
DA 2026-03-10
ER

PT J
AU PETRIE, S
   BOHME, DK
AF PETRIE, S
   BOHME, DK
TI ENHANCED REACTIVITY OF FULLERENE CATIONS CONTAINING ADJACENT PENTAGONS
SO NATURE
LA English
DT Article
ID carbon cluster ions; gas-phase; c-60; buckminsterfullerene; view
AB GEOMETRICAL constraints, first identified by Euler, dictate that all of the closed carbon cages known as fullerenes must contain twelve pentagonal rings of carbon atoms1. In all of the fullerenes synthesized so far, each pentagon is surrounded by hexagonal rings2. Indeed, this has been proposed as a criterion for fullerene stability-the 'isolated-pentagon rule'1,3-on the basis that adjacent pentagons are expected to be chemically reactive. Buck-minsterfullerene (C60) is the smallest fullerene for which the isolated-pentagon rule can be satisfied; smaller, adjacent-pentagon fullerenes have not been formed in bulk, but have been identified previously as cations4-6. Here we report experimental evidence for the heightened chemical reactivity of cations of the adjacent-pentagon fullerenes C56 and C58, relative to C60x+, which provides support for the basic assumptions underlying the isolated-pentagon rule. Our findings suggest that, if fullerenes such as C56 and C58 are produced as intermediates or byproducts of C60 generation either in the laboratory or in natural environments, they should form derivatives readily.
C1 YORK UNIV,CTR RES EARTH & SPACE SCI,N YORK M3J 1P3,ONTARIO,CANADA.
C3 York University - Canada
RP PETRIE, S (corresponding author), YORK UNIV,DEPT CHEM,N YORK M3J 1P3,ONTARIO,CANADA.
NR 25
TC 44
Z9 44
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 426
EP 429
DI 10.1038/365426a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300051
DA 2026-03-10
ER

PT J
AU LI, N
   BATZER, A
   DALY, R
   YAJNIK, V
   SKOLNIK, E
   CHARDIN, P
   BARSAGI, D
   MARGOLIS, B
   SCHLESSINGER, J
AF LI, N
   BATZER, A
   DALY, R
   YAJNIK, V
   SKOLNIK, E
   CHARDIN, P
   BARSAGI, D
   MARGOLIS, B
   SCHLESSINGER, J
TI GUANINE-NUCLEOTIDE-RELEASING FACTOR HSOS1 BINDS TO GRB2 AND LINKS RECEPTOR TYROSINE KINASES TO RAS SIGNALING
SO NATURE
LA English
DT Article
ID growth-factor; vulvar induction; pc12 cells; differentiation; requirement; p21ras.gtp; sevenless; pathway; gene
AB MANY of the actions of receptor tyrosine kinases are mediated by the protein Ras1-5, including the activation of various downstream serine/threonine kinases and the stimulation of growth and differentiation6-12. The human protein Grb2 binds to ligand-activated growth factor receptors and downstream effector proteins through its Src-homology (SH) domains SH2 and SH3, respectively13,14, and like its homologue from Caenorhabditis elegans, Sem-5, apparently forms part of a highly conserved pathway by which these receptors can control Ras activity15-18. Here we show that the SH3 domains of Grb2 bind to the carboxy-terminal part of hSos1, the human homologue of the Drosophila guanine-nucleotide-releasing factor for Ras, which is essential for control of Ras activity by epidermal growth factor receptor and sevenless19,20. Moreover, a synthetic 10-amino-acid peptide containing the sequence PPVPPR specifically blocks the interaction. These results indicate that the Grb2/hSos1 complex couples activated EGF receptor to Ras signalling.
C1 KAPLAN CANC CTR,NEW YORK,NY 10016.
   CNRS,INST PHARMACOL MOLEC,F-06560 VOLBONNE,FRANCE.
   COLD SPRING HARBOR LAB,COLD SPRING HARBOR,NY 11724.
C3 Centre National de la Recherche Scientifique (CNRS); Cold Spring Harbor Laboratory
RP LI, N (corresponding author), NYU MED CTR,DEPT PHARMACOL,550 1ST AVE,NEW YORK,NY 10016, USA.
NR 30
TC 936
Z9 1056
U1 0
U2 16
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 85
EP 88
DI 10.1038/363085a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200066
PM 8479541
DA 2026-03-10
ER

PT J
AU CROWLEY, TE
   HOEY, T
   LIU, JK
   JAN, YN
   JAN, LY
   TJIAN, R
AF CROWLEY, TE
   HOEY, T
   LIU, JK
   JAN, YN
   JAN, LY
   TJIAN, R
TI A NEW FACTOR RELATED TO TATA-BINDING PROTEIN HAS HIGHLY RESTRICTED EXPRESSION PATTERNS IN DROSOPHILA
SO NATURE
LA English
DT Article
ID rna polymerase-ii; transcriptional activation; nervous-system; initiation; coactivators; embryos
AB THE TATA-binding protein TBP is necessary for the transcription of eukaryotic genes. Multi-protein complexes formed by TBP and different TBP-associated factors are involved in the initiation of transcription by polymerases I and II, and probably ill as well1. During the formation of an active initiation complex, TBP makes specific contacts with other proteins, for example TFIIB and RNA polymerase II (refs 2-4). Here we describe the cloning and characterization of a Drosophila gene product with considerable sequence similarity to TBP and a highly restricted expression pattern in the embryo. This TBP-related factor is a DNA-binding protein but is not likely to be a basal transcription factor. Our results suggest that TBP-related factor is a sequence-specific transcription factor that shares the DNA-binding properties of TBP.
C1 UNIV CALIF SAN FRANCISCO,HOWARD HUGHES MED INST,SAN FRANCISCO,CA 94143.
   UNIV CALIF SAN FRANCISCO,DEPT PHYSIOL,SAN FRANCISCO,CA 94143.
   UNIV CALIF BERKELEY,HOWARD HUGHES MED INST,BERKELEY,CA 94720.
   UNIV CALIF SAN FRANCISCO,DEPT BIOCHEM & BIOPHYS,SAN FRANCISCO,CA 94143.
   UNIV CALIF BERKELEY,DEPT MOLEC & CELL BIOL,BERKELEY,CA 94720.
C3 University of California System; University of California San Francisco; Howard Hughes Medical Institute; University of California System; University of California San Francisco; Howard Hughes Medical Institute; University of California System; University of California Berkeley; University of California System; University of California San Francisco; University of California System; University of California Berkeley
NR 26
TC 107
Z9 124
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 557
EP 561
DI 10.1038/361557a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400068
PM 8429912
DA 2026-03-10
ER

PT J
AU HALLWORTH, MA
   PHILLIPS, JC
   HUPPERT, HE
   SPARKS, RSJ
AF HALLWORTH, MA
   PHILLIPS, JC
   HUPPERT, HE
   SPARKS, RSJ
TI ENTRAINMENT IN TURBULENT GRAVITY CURRENTS
SO NATURE
LA English
DT Article
AB LABORATORY gravity currents are frequently used to model a range of environmental and industrial flows1. The manner in which these flows become diluted with distance by the surrounding fluid has important implications for turbidity currents2, pyroclastic flows3,4, avalanches5, accidental dense gas releases6, fire propagation7 and emission of industrial pollutants. Here we present an experimental technique for quantifying the entrainment of ambient fluid into the head of a gravity current propagating along a horizontal surface. The technique relies on the neutralization of an alkaline current by entrainment of acidic ambient fluid, and is visualized by using a pH indicator. Dimensional analysis indicates that the proportion of ambient fluid entrained into a gravity current head depends only on the initial volume of the current and distance from the release point, and is independent of the initial value of the density difference. This result is confirmed by the experimental data, which also show that little dilution of the head takes place during the slumping phase8,9. Thereafter the dilution increases with the downstream distance, in quantitative agreement with the predictions of a theoretical model which evaluates the volume of entrained fluid. We apply the results to show that sediment slumps of initially high sediment concentrations will become dilute turbidity currents owing to entrainment of sea water before they have propagated extensively over the floors of ocean basins.
C1 UNIV CAMBRIDGE,DEPT APPL MATH & THEORET PHYS,CAMBRIDGE CB3 9EW,ENGLAND.
   UNIV BRISTOL,DEPT GEOL,BRISTOL BS8 1RJ,ENGLAND.
C3 University of Cambridge; University of Bristol
RP HALLWORTH, MA (corresponding author), UNIV CAMBRIDGE,DEPT EARTH SCI,INST THEORET GEOPHYS,CAMBRIDGE CB3 9EW,ENGLAND.
NR 14
TC 85
Z9 95
U1 0
U2 19
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 829
EP 831
DI 10.1038/362829a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300052
DA 2026-03-10
ER

PT J
AU SUNG, P
   BAILLY, V
   WEBER, C
   THOMPSON, LH
   PRAKASH, L
   PRAKASH, S
AF SUNG, P
   BAILLY, V
   WEBER, C
   THOMPSON, LH
   PRAKASH, L
   PRAKASH, S
TI HUMAN XERODERMA-PIGMENTOSUM GROUP-D GENE ENCODES A DNA HELICASE
SO NATURE
LA English
DT Article
AB XERODERMA pigmentosum (XP), a genetically heterogeneous human disease, results from a defect in nucleotide excision repair of ultraviolet-damaged DNA. XP patients are extremely sensitive to sunlight and suffer from a high incidence of skin cancers. Cell fusion studies have identified seven XP complementation groups, A-G1-3. Group D is of particular interest as mutations in this gene can also cause Cockayne's syndrome and trichothiodystrophy4. The XPD gene was initially named ERCC2 (excision repair cross complementing) as it was cloned using human DNA to complement the ultraviolet sensitivity of a rodent cell line5. We have purified the XPD protein to near homogeneity and show that it possesses single-stranded DNA-dependent ATPase and DNA helicase activities. We tested whether XPD can substitute for its yeast counterpart RAD3, which is essential for excision repair and for cell viability6. Expression of the XPD gene in Saccharomyces cerevisiae can complement the lethality defect of a mutation in the RAD3 gene6, suggesting that XPD is an essential gene in humans.
C1 UNIV ROCHESTER,DEPT BIOL,ROCHESTER,NY 14627.
   UNIV ROCHESTER,SCH MED,DEPT BIOPHYS,ROCHESTER,NY 14642.
   LAWRENCE LIVERMORE NATL LAB,BIOL & TECHNOL RES PROGRAM,LIVERMORE,CA 94550.
C3 University of Rochester; University of Rochester; United States Department of Energy (DOE); Lawrence Livermore National Laboratory
NR 17
TC 298
Z9 323
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 852
EP 855
DI 10.1038/365852a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100055
PM 8413672
DA 2026-03-10
ER

PT J
AU OCARROLL, D
AF OCARROLL, D
TI FEATURE-DETECTING NEURONS IN DRAGONFLIES
SO NATURE
LA English
DT Article
ID cells; discrimination; movement; stimuli; object; motion; system
AB SINCE the earliest descriptions1 of the compound eye, the popular impression has prevailed that insects and mammals view the world differently. Recent work, however, underscores marked evolutionary convergence between the visual systems of vertebrates and insects at both optical2,3 and early processing levels4,5. Here I describe several classes of cells from the third optic ganglion of dragonflies that respond selectively to different target classes. Several physiological properties of these cells are remarkably similar to those of cells from areas 17, 18 and 19 of the mammalian visual cortex. One class of bar-sensitive, orientation-biased cells could mediate discrimination of the orientation of low spatial frequency components of patterns. The existence of neurons functionally similar in many respects to those in the mammalian cortex suggests that evolutionary convergence in visual processing is not limited to early pathways. Insects, like mammals, seem to possess mechanisms for extracting spatial features from visual scenes.
C1 AUSTRALIAN NATL UNIV,RES SCH BIOL SCI,CTR VISUAL SCI,CANBERRA,ACT 2601,AUSTRALIA.
C3 Australian National University
NR 24
TC 165
Z9 175
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 541
EP 543
DI 10.1038/362541a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300054
DA 2026-03-10
ER

PT J
AU CUMBERLEDGE, S
   KRASNOW, MA
AF CUMBERLEDGE, S
   KRASNOW, MA
TI INTERCELLULAR SIGNALING IN DROSOPHILA SEGMENT FORMATION RECONSTRUCTED INVITRO
SO NATURE
LA English
DT Article
ID polarity gene armadillo; wingless; expression; embryos; embryogenesis; requirements; epidermis; protein
AB GENETIC studies show that intercellular signalling is involved in key steps in Drosophila melanogaster development, but it has not previously been possible to investigate these processes in simplified in vitro systems. Analysis of engrailed (en) and wingless (wg) and other segment polarity genes suggests that two or more intercellular signalling processes may be involved in intrasegmental patterning1-3. Expression of en and wg begins about three hours after egg laying, in adjacent rows of cells in the posterior half of each segmental primordium4-7. In wg- embryos and in conditional mutants in which wg function is inactivated during a critical period between three and five hours after egg laying, early en expression begins normally but then disappears within several hours4,8-10. The wg gene encodes a protein highly similar to the product of the mouse Wnt-1 proto-oncogene, a secreted glycoprotein11,12; wg protein is proposed to function as an extracellular signal, maintaining en expression and activating other molecular and morphogenetic processes in nearby cells4,8,9,13. Several lines of evidence support the model, including the secretion of wg protein in the embryo7,14, genetic mosaic experiments15-17 and cell lineage studies18. We tested this model using purified embryonic cells isolated by whole animal cell sorting19, and validated three key predictions: (1) when en-expressing cells from early embryos are grown alone in culture, they rapidly and selectively lose en expression; (2) purified wg-expressing cells provide a locally active signal that prevents this loss; (3) heterologous cells engineered to express wg also show signalling activity, indicating that wg protein alone, or in conjunction with more generally expressed factors, is the signal.
RP CUMBERLEDGE, S (corresponding author), STANFORD UNIV,SCH MED,DEPT BIOCHEM,STANFORD,CA 94305, USA.
NR 21
TC 46
Z9 51
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 549
EP 552
DI 10.1038/363549a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900052
PM 8505983
DA 2026-03-10
ER

PT J
AU PAYTAN, A
   KASTNER, M
   MARTIN, EE
   MACDOUGALL, JD
   HERBERT, T
AF PAYTAN, A
   KASTNER, M
   MARTIN, EE
   MACDOUGALL, JD
   HERBERT, T
TI MARINE BARITE AS A MONITOR OF SEAWATER STRONTIUM ISOTOPE COMPOSITION
SO NATURE
LA English
DT Article
ID deep-sea sediments; interstitial waters; equatorial pacific; phanerozoic time; stratigraphy; evolution; ocean; diagenesis; carbonate; particles
AB THE strontium isotope ratio in sea water is influenced by climate, tectonics, weathering and hydrothermal activity at ocean ridges1-4. Its evolution through time, determined primarily by measuring the strontium isotope composition of marine carbonates, holds information about variations in these processes, and is also useful for stratigraphic correlation and dating5-7.  Carbonates are absent from some marine sediments such as siliceous oozes and red clays, and can be significantly diagenetically altered in others, especially in Eocene and older sediments. Here we show that marine barite is an effective alternative monitor of seawater Sr-87/Sr-86. We find that microcrystals of marine barite separated from Holocene Pacific, Atlantic and Indian Ocean sediments all record the modern seawater Sr-87/Sr-86 value. Moreover, the Sr-87/Sr-86 of barite from 25 sediment samples spanning the past 35 Myr falls within the range of published data for carbonates over this time period. We conclude that marine barite reliably records both present and past variations in seawater strontium isotope composition.
RP PAYTAN, A (corresponding author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA.
NR 40
TC 201
Z9 241
U1 1
U2 68
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 445
EP 449
DI 10.1038/366445a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800058
DA 2026-03-10
ER

PT J
AU GHISLAIN, M
   UDVARDY, A
   MANN, C
AF GHISLAIN, M
   UDVARDY, A
   MANN, C
TI SACCHAROMYCES-CEREVISIAE 26S PROTEASE MUTANTS ARREST CELL-DIVISION IN G2/METAPHASE
SO NATURE
LA English
DT Article
ID n-end rule; saccharomyces-cerevisiae; ubiquitin pathway; invivo function; yeast; cycle; degradation; mitosis; member; family
AB WE isolated two mutants from the yeast Saccharomyces cerevisiae, cim3-1 and cim5-1, that arrest cell division in G2/metaphase at 37-degrees-C. CIM3 (identical to SUG1; ref. 1) and CIM5 are similar to each other and are members of a family of putative ATPases that have been proposed to be 26S protease subunits2. We show here that CIM5 is the functional yeast homologue of the human MSS1 protein3 and that homologues of CIM3 and CIM5 are present in a highly purified preparation of the Drosophila 26S protease4. The short-lived ubiquitin-proline-beta-galactosidase fusion protein is stabilized in cim mutants, but Leu-beta-galactosidase is not. The CLB2 and CLB3 cyclins also accumulate in the cim mutants. Thus the 26S protease is required in vivo for the degradation of ubiquitinated substrates and for anaphase chromosome separation.
C1 CTR ETUD SACLAY, DEPT BIOL CELLULAIRE & MOLEC, SERV BIOCHIM & GENET MOLEC, F-91191 GIF SUR YVETTE, FRANCE.
   HUNGARIAN ACAD SCI, INST BIOCHEM, BIOL RES CTR, H-6701 SZEGED, HUNGARY.
C3 Hungarian Academy of Sciences; HUN-REN; HUN-REN Biological Research Center; Institute of Biochemistry - HAS
NR 30
TC 396
Z9 414
U1 0
U2 7
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 358
EP 362
DI 10.1038/366358a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500053
PM 8247132
DA 2026-03-10
ER

PT J
AU LAHAV, O
   FABIAN, AC
   BARCONS, X
   BOLDT, E
   BUTCHER, J
   CARRERA, FJ
   JAHODA, K
   MIYAJI, T
   STEWART, GC
   WARWICK, RS
AF LAHAV, O
   FABIAN, AC
   BARCONS, X
   BOLDT, E
   BUTCHER, J
   CARRERA, FJ
   JAHODA, K
   MIYAJI, T
   STEWART, GC
   WARWICK, RS
TI A SIGNIFICANT CONTRIBUTION TO THE COSMIC X-RAY-BACKGROUND FROM SOURCES ASSOCIATED WITH NEARBY GALAXIES
SO NATURE
LA English
DT Article
ID iras galaxy; redshift survey; origin; sample
AB THE origin of the cosmic X-ray background remains a mystery after thirty years of study. The three properties of the background radiation commonly used for tackling this problem-its spectrum, isotropy and resolved component-are well defined by observations, but do not lead to a simple interpretation. A different approach to the problem1,2, in which fluctuations in the unresolved component are cross-correlated with galaxy catalogues, has led to the suggestion2 that as much as 60% of the background emission can be explained by a population of X-ray sources similar to present-day optically bright galaxies. Here we point out that such analyses must allow for contributions from X-ray sources which cluster with the galaxies, but do not necessarily have a counterpart in galaxy catalogues. For realistic assumptions about clustering, we obtain a revised limit on the local X-ray emissivity due to sources correlated with nearby galaxies. Extrapolating these results up to a redshift of approximately 5, we find that a smaller, but still significant, fraction of the X-ray background (30 +/- 15%) can be accounted for by these sources. To explain the residual background emissions, evolution of the source properties and/or a new population of sources at high redshift is required.
C1 UNIV CANTABRIA, DEPT FIS MODERNA, E-39005 SANTANDER, SPAIN.
   NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA.
   UNIV LEICESTER, DEPT PHYS, X-RAY ASTRON GRP, LEICESTER LE1 7RH, ENGLAND.
   UCL, MULLARD SPACE SCI LAB, DORKING RH5 6NT, SURREY, ENGLAND.
   UNIV MARYLAND, DEPT ASTRON, College Pk, MD 20742 USA.
C3 Universidad de Cantabria; National Aeronautics & Space Administration (NASA); NASA Goddard Space Flight Center; University of Leicester; University of London; University College London; University System of Maryland; University of Maryland College Park
RP LAHAV, O (corresponding author), UNIV CAMBRIDGE, INST ASTRON, MADINGLEY RD, CAMBRIDGE CB3 0HA, ENGLAND.
NR 25
TC 37
Z9 37
U1 0
U2 0
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 693
EP 695
DI 10.1038/364693a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700048
DA 2026-03-10
ER

PT J
AU GIAEVER, I
   KEESE, CR
AF GIAEVER, I
   KEESE, CR
TI A MORPHOLOGICAL BIOSENSOR FOR MAMMALIAN-CELLS
SO NATURE
LA English
DT Article
ID tissue-culture; electric-fields; behavior; monitor
AB An electrical biosensor is described that can continuously track morphological changes of adherent cells providing quantitative data from both sparse and confluent cultures. The method is capable of detecting vertical motion of cells of the order of 1 nm, much below the resolution of an optical microscope.
C1 RENSSELAER POLYTECH INST,DEPT BIOL,TROY,NY 12180.
C3 Rensselaer Polytechnic Institute
RP GIAEVER, I (corresponding author), RENSSELAER POLYTECH INST,SCH SCI,TROY,NY 12180, USA.
NR 11
TC 653
Z9 746
U1 2
U2 107
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 591
EP 592
DI 10.1038/366591a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800078
PM 8255299
DA 2026-03-10
ER

PT J
AU JEWITT, D
   LUU, J
AF JEWITT, D
   LUU, J
TI DISCOVERY OF THE CANDIDATE KUIPER BELT OBJECT 1992 QB(1)
SO NATURE
LA English
DT Article
ID short-period comets; chaotic motion; solar-system; neptune; 2060-chiron; origin; disk
AB THE apparent emptiness of the outer Solar System has been a long-standing puzzle for astronomers, as it contrasts markedly with the abundance of asteroids and short-period comets found closer to the Sun. One explanation for this might be that the orbits of distant objects are intrinsically short-lived, perhaps owing to the gravitational influence of the giant planets. Another possibility is that such objects are very faint, and thus they might easily go undetected. An early survey1 designed to detect distant objects culminated with the discovery of Pluto. More recently, similar surveys yielded the comet-like objects 2060 Chiron2 and 5145 Pholus3 beyond the orbit of Saturn. Here we report the discovery of a new object, 1992 QB1, moving beyond the orbit of Neptune. We suggest that this may represent the first detection of a member of the Kuiper belt4,5, the hypothesized population of objects beyond Neptune and a possible source of the short-period comets6-8.
C1 UNIV CALIF BERKELEY, DEPT ASTRON, BERKELEY, CA 94720 USA.
C3 University of California System; University of California Berkeley
RP JEWITT, D (corresponding author), UNIV HAWAII, INST ASTRON, 2680 WOODLAWN DR, HONOLULU, HI 96822 USA.
NR 26
TC 385
Z9 431
U1 0
U2 11
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 730
EP 732
DI 10.1038/362730a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000048
DA 2026-03-10
ER

PT J
AU NISHIMOTO, I
   OKAMOTO, T
   MATSUURA, Y
   TAKAHASHI, S
   OKAMOTO, T
   MURAYAMA, Y
   OGATA, E
AF NISHIMOTO, I
   OKAMOTO, T
   MATSUURA, Y
   TAKAHASHI, S
   OKAMOTO, T
   MURAYAMA, Y
   OGATA, E
TI ALZHEIMER AMYLOID PROTEIN-PRECURSOR COMPLEXES WITH BRAIN GTP-BINDING PROTEIN-G(O)
SO NATURE
LA English
DT Article
ID growth factor-ii; pertussis-toxin; disease; receptor; expression; g0; fragment; peptide; gap-43
AB THE most characteristic change in progressive dementia of Alzheimer's type is a tissue deposit of amyloid beta/A4 protein1, which is derived from its precursor protein APP (ref. 2). Structural alterations of APP are implicated in the pathogenesis of Alzheimer's disease, but it is not known how they cause the disease. Although APP has a receptor-like architecture 2-5, is located on the neuronal surface6, and has a conserved cytoplasmic domain7, no receptor function has been demonstrated for APP. Here we report that APP forms a complex with G(o), a major GTP-binding protein in brain. The cytoplasmic APP sequence His 657-Lys 676 shows a specific G(o)-activating function and is necessary for complex formation. G(o) protein treated with GTP-gammaS lost the ability to associate with APP. This suggests that APP is a receptor coupled to G(o) and that abnormal APP-G(o) signalling is involved in the Alzheimer's disease process.
C1 UNIV TOKYO,SCH MED,DEPT INTERNAL MED 4,LIFE SCI LAB,BUNKYO KU,TOKYO 112,JAPAN.
   NATL INST HLTH,DEPT VIROL 2,HEPATITIS VIRUSES LAB,SHINJUKU KU,TOKYO 160,JAPAN.
   SAPPORO MED COLL,DEPT PATHOL,CHUO KU,SAPPORO,HOKKAIDO 060,JAPAN.
C3 University of Tokyo; Sapporo Medical University
NR 27
TC 395
Z9 437
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 75
EP 79
DI 10.1038/362075a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600065
PM 8446172
DA 2026-03-10
ER

PT J
AU MILLER, JD
   WILHELM, H
   GIERASCH, L
   GILMORE, R
   WALTER, P
AF MILLER, JD
   WILHELM, H
   GIERASCH, L
   GILMORE, R
   WALTER, P
TI GTP-BINDING AND HYDROLYSIS BY THE SIGNAL RECOGNITION PARTICLE DURING INITIATION OF PROTEIN TRANSLOCATION
SO NATURE
LA English
DT Article
ID methionine-rich domain; endoplasmic-reticulum; microsomal membrane; docking protein; 54-kd protein; receptor; sequence; subunit; contains; polypeptide
AB THE signal recognition particle (SRP) consists of one RNA and six protein subunits1,2. The N-terminal domain of the 54K subunit contains a putative GTP-binding site, whereas the C-terminal domain binds signal sequences and SRP RNA3-7. Binding of SRP to the signal sequence as it emerges from the ribosome creates a cytosolic targeting complex containing the nascent polypeptide chain, the translating ribosome, and SRP8. This complex is directed to the endoplasmic reticulum membrane as a result of its interaction with the SRP receptor9-11, a membrane protein composed of two subunits, SRalpha and SRbeta, each of which also contains a GTP-binding domain12,13. In the presence of GTP, SRP receptor binding to SRP causes the latter to dissociate from both the signal sequence and the ribosome13,14. GTP is then hydrolysed so that SRP can be released from the SRP receptor and returned to the cytosol15. Here we show that the 54K subunit (M(r) 54,000) of SRP (SRP54) is a GTP-binding protein stabilized in a nucleotide-free state by signal sequences and that the SRP receptor both increases the affinity of SRP54 for GTP and activates its GTPase. We propose that nucleotide-mediated conformational changes in SRP54 regulate the release of signal sequences and the docking of ribosomes at the endoplasmic reticulum.
C1 UNIV TEXAS, SW MED CTR, DEPT PHARMACOL, DALLAS, TX 75235 USA.
   UNIV MASSACHUSETTS, DEPT BIOCHEM, WORCESTER, MA 01655 USA.
C3 University of Texas System; University of Texas Southwestern Medical Center; University of Texas Dallas; University of Massachusetts System; University of Massachusetts Worcester
RP MILLER, JD (corresponding author), UNIV CALIF SAN FRANCISCO, SCH MED, DEPT BIOCHEM & BIOPHYS, SAN FRANCISCO, CA 94143 USA.
NR 32
TC 163
Z9 194
U1 0
U2 4
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 351
EP 354
DI 10.1038/366351a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500051
PM 8247130
DA 2026-03-10
ER

PT J
AU RUSSELL, TP
   DELINE, VR
   DOZIER, WD
   FELCHER, GP
   AGRAWAL, G
   WOOL, RP
   MAYS, JW
AF RUSSELL, TP
   DELINE, VR
   DOZIER, WD
   FELCHER, GP
   AGRAWAL, G
   WOOL, RP
   MAYS, JW
TI DIRECT OBSERVATION OF REPTATION AT POLYMER INTERFACES
SO NATURE
LA English
DT Article
ID theoretical-models; relaxation; dynamics; systems; chain; melts; diffusion; segments; kinetics; motion
AB ALTHOUGH the diffusion of polymer chains in the liquid state can be described over long distances by classical diffusion laws, chain entanglements make a description of the short-range behaviour more complex. In the standard 'reptation' model1,2 the polymer chains are considered to move in a curvilinear manner along their own contours, exhibiting snake-like motion through the entangled sea of surrounding molecules. This model successfully explains many observations3-13, yet no direct evidence for reptative motion has been reported. Here we describe the observation of reptation of molecules across the interface between two types of partially deuterated polystyrene polymers. The time evolution of the hydrogen and deuterium profiles, determined by dynamic secondary-ion mass spectrometry, can be explained only on the basis of a reptation model. Our results demonstrate that, despite being inevitably simplified, the description of polymer diffusion in terms of reptation is essentially correct.
C1 ARGONNE NATL LAB, ARGONNE, IL 60439 USA.
   UNIV ILLINOIS, DEPT MAT SCI & ENGN, URBANA, IL 61801 USA.
   UNIV ALABAMA, DEPT CHEM, BIRMINGHAM, AL 35294 USA.
C3 United States Department of Energy (DOE); Argonne National Laboratory; University of Illinois System; University of Illinois Urbana-Champaign; University of Alabama System; University of Alabama Birmingham
RP RUSSELL, TP (corresponding author), IBM CORP, ALMADEN RES CTR, DIV RES, 650 HARRY RD, SAN JOSE, CA 95120 USA.
NR 27
TC 84
Z9 92
U1 0
U2 44
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 235
EP 237
DI 10.1038/365235a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100047
DA 2026-03-10
ER

PT J
AU COX, GA
   COLE, NM
   MATSUMURA, K
   PHELPS, SF
   HAUSCHKA, SD
   CAMPBELL, KP
   FAULKNER, JA
   CHAMBERLAIN, JS
AF COX, GA
   COLE, NM
   MATSUMURA, K
   PHELPS, SF
   HAUSCHKA, SD
   CAMPBELL, KP
   FAULKNER, JA
   CHAMBERLAIN, JS
TI OVEREXPRESSION OF DYSTROPHIN IN TRANSGENIC MDX MICE ELIMINATES DYSTROPHIC SYMPTOMS WITHOUT TOXICITY
SO NATURE
LA English
DT Article
ID duchenne muscular-dystrophy; skeletal-muscle; expression; mouse; glycoprotein; protein; deficiency; membrane; complex
AB DUCHENNE and Becker muscular dystrophy (DMD and BMD) are X-linked recessive diseases caused by defective expression of dystrophin1,2. The mdx mouse, an animal model for DMD, has a mutation that eliminates expression of the 427K muscle and brain isoforms of dystrophin1,3,4. Although these animals do not display overt muscle weakness or impaired movement, the diaphragm muscle of the mdx mouse is severely affected and shows progressive myofibre degeneration and fibrosis which closely resembles the human disease5,6. Here we explore the feasibility of gene therapy for DMD by examining the potential of a full-length dystrophin transgene to correct dystrophic symptoms in mdx mice. We find that expression of dystrophin in muscles of transgenic mdx mice eliminates the morphological and immunohistological symptoms of muscular dystrophy. In addition, overexpression of dystrophin prevents the development of the abnormal mechanical properties associated with dystrophic muscle without causing deleterious side effects. Our results provide functional evidence for the feasibility of gene therapy for DMD.
C1 UNIV MICHIGAN,SCH MED,DEPT HUMAN GENET,ANN ARBOR,MI 48109.
   UNIV MICHIGAN,SCH MED,INST GERONTOL,ANN ARBOR,MI 48109.
   UNIV MICHIGAN,SCH MED,CTR HUMAN GENOME,ANN ARBOR,MI 48109.
   UNIV IOWA,COLL MED,HOWARD HUGHES MED INST,IOWA CITY,IA 52242.
   UNIV IOWA,COLL MED,DEPT PHYSIOL & BIOPHYS,IOWA CITY,IA 52242.
   UNIV WASHINGTON,DEPT BIOCHEM,SEATTLE,WA 98195.
C3 University of Michigan System; University of Michigan; University of Michigan System; University of Michigan; University of Michigan System; University of Michigan; Howard Hughes Medical Institute; University of Iowa; University of Iowa; University of Washington; University of Washington Seattle
NR 27
TC 261
Z9 297
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 725
EP 729
DI 10.1038/364725a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700061
PM 8355788
DA 2026-03-10
ER

PT J
AU BREKKE, OH
   MICHAELSEN, TE
   SANDIN, R
   SANDLIE, I
AF BREKKE, OH
   MICHAELSEN, TE
   SANDIN, R
   SANDLIE, I
TI ACTIVATION OF COMPLEMENT BY AN IGG MOLECULE WITHOUT A GENETIC HINGE
SO NATURE
LA English
DT Article
ID segmental flexibility; 3-dimensional structure; immunoglobulin-g; chimeric human; c1q binding; antibody; expression; region; site
AB THE hinge region links the two Fab arms to the Fc portion of the IgG molecule. It mediates flexibility to the molecule and serves as a connecting structure between the two heavy chains. In addition it provides space between the Fab and Fc parts. All three properties have been proposed to be important for the ability of IgG to initiate complement activation leading to complement-mediated cell lysis (CML)1. Here we report the construction of a hinge-deleted mouse-human chimaeric IgG3 molecule with specificity for the hapten NIP (3-iodo-4-hydroxy-5-nitrophenacetyl), HM-1. HM-1 lacks the genetic hinge, but has an introduced cysteine between Ala 231 (EU numbering) and Pro 232 in the lower hinge encoded by the C(H)2 exon. The introduced cysteine forms a disulphide bond between the two heavy chains of the molecule. In CML, HM-1 shows a greater activity than IgG3 wild type. This is the first time an IgG molecule without a genetic hinge has been found to be active in CML. We conclude that the hinge functioning as a spacer is not a prerequisite for complement activation. Rather, its major role seems to be to connect the heavy chains to each other in the amino-terminal part of C(H)2. Because HM-1 is expected to have low Fab-Fc flexibility, this molecular feature is probably of no importance for complement activation.
C1 UNIV OSLO,DEPT BIOL,POB 1050,N-0316 BLINDERN,NORWAY.
   NATL INST PUBL HLTH,N-0462 OSLO,NORWAY.
C3 University of Oslo
NR 25
TC 35
Z9 44
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 17
PY 1993
VL 363
IS 6430
BP 628
EP 630
DI 10.1038/363628a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LH139
UT WOS:A1993LH13900056
PM 8510754
DA 2026-03-10
ER

PT J
AU DUVALL, TL
   JEFFERIES, SM
   HARVEY, JW
   POMERANTZ, MA
AF DUVALL, TL
   JEFFERIES, SM
   HARVEY, JW
   POMERANTZ, MA
TI TIME DISTANCE HELIOSEISMOLOGY
SO NATURE
LA English
DT Article
ID acoustic modes; solar; oscillations
AB THE application of seismology to the study of the solar interior1,2 (helioseismology) has advanced almost solely by the prediction and measurement of the Sun's frequencies of free oscillation, or normal modes. Direct measurement of the travel times and distances of individual acoustic waves-the predominant approach in terrestrial seismology3-would appear to be more difficult in view of the number and stochastic nature of solar seismic sources. Here, however, we show that it is possible to extract time-distance information from temporal cross-correlations of the intensity fluctuations on the solar surface. This approach opens the way for seismic studies of local solar phenomena, such as subsurface inhomogeneities near sunspots, and should help to refine global models of the internal velocity stratification in the Sun.
C1 UNIV DELAWARE,BARTOL RES INST,NEWARK,DE 19716.
   NATL OPT ASTRON OBSERV,NATL SOLAR OBSERV,TUCSON,AZ 85726.
C3 University of Delaware; National Optical Astronomy Observatory; National Solar Observatory
RP DUVALL, TL (corresponding author), NASA,GODDARD SPACE FLIGHT CTR,ASTRON & SOLAR PHYS LAB,GREENBELT,MD 20771, USA.
NR 17
TC 631
Z9 667
U1 0
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 430
EP 432
DI 10.1038/362430a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400076
DA 2026-03-10
ER

PT J
AU HASTY, P
   BRADLEY, A
   MORRIS, JH
   EDMONDSON, DG
   VENUTI, JM
   OLSON, EN
   KLEIN, WH
AF HASTY, P
   BRADLEY, A
   MORRIS, JH
   EDMONDSON, DG
   VENUTI, JM
   OLSON, EN
   KLEIN, WH
TI MUSCLE DEFICIENCY AND NEONATAL DEATH IN MICE WITH A TARGETED MUTATION IN THE MYOGENIN GENE
SO NATURE
LA English
DT Article
ID acetylcholine-receptor; regulatory gene; messenger-rna; mouse embryo; expression; region; cdna; subunit; myod; differentiation
AB Myogenin is a muscle-specific transcription factor that can induce myogenesis in a variety of cell types in tissue culture. To test myogenin's role in vivo, mice homozygous for a targeted mutation in the myogenin gene were generated. These mice survive fetal development but die immediately after birth and show a severe reduction of all skeletal muscle. Myogenin-mutant mice differ from mice carrying mutations in genes for the related myogenic factors Myf5 and MyoD, which have no muscle defects. Myogenin is therefore essential for the development of functional skeletal muscle.
C1 BAYLOR COLL MED,HOWARD HUGHES MED INST,HOUSTON,TX 77030.
   UNIV TEXAS,MD ANDERSON CANC CTR,DEPT BIOCHEM & MOLEC BIOL,HOUSTON,TX 77030.
C3 Howard Hughes Medical Institute; Baylor College of Medicine; University of Texas System; UTMD Anderson Cancer Center
RP HASTY, P (corresponding author), BAYLOR COLL MED,INST MOLEC GENET,HOUSTON,TX 77030, USA.
NR 36
TC 1139
Z9 1402
U1 2
U2 50
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 501
EP 506
DI 10.1038/364501a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700044
PM 8393145
DA 2026-03-10
ER

PT J
AU PAWLOWSKI, T
   ELLIOTT, JD
   LOH, DY
   STAERZ, UD
AF PAWLOWSKI, T
   ELLIOTT, JD
   LOH, DY
   STAERZ, UD
TI POSITIVE SELECTION OF T-LYMPHOCYTES ON FIBROBLASTS
SO NATURE
LA English
DT Article
ID major histocompatibility complex; cell receptor; hematopoietic-cells; monoclonal-antibody; antigen receptor; mice; thymus; line; differentiation; specificity
AB THYMOCYTES are selected for expression of alphabeta T-cell antigen receptors (TCR) which recognize antigen in conjunction with self-major histocompatibility complex (MHC) molecules1,2. In the thymus the restriction element is imprinted on radioresistant stromal elements3-7 and on cells of haematopoietic origin8-10. In mice negative for beta2-microglobulin that are devoid of mature cytotoxic T lymphocytes11, we find that intrathymic injection of different fibroblasts causes the maturation of CD4-CD8+TCR(high) thymocytes with distinct patterns of TCR Vbeta distribution. Here we show that in TCR-transgenic mice, intrathymic injection of L cells expressing the selecting H-2K(b) molecule (L-K(b) cells) reconstitutes the maturation of thymocytes bearing the- transgenic TCR, and that in normal B10.BR (H-2k) mice, H-2K(b) Molecules expressed on L-K(b) cells lead to the development of T lymphocytes with recognition restricted to H-2K(b). A class I MHC restriction element can thus be selected by interaction with fibroblasts, that is, cells of other than epithelial or haematopoietic origin3-10.
C1 WASHINGTON UNIV,SCH MED,HOWARD HUGHES MED INST,DEPT MED,ST LOUIS,MO 63110.
   WASHINGTON UNIV,SCH MED,HOWARD HUGHES MED INST,DEPT GENET,ST LOUIS,MO 63110.
   WASHINGTON UNIV,SCH MED,HOWARD HUGHES MED INST,DEPT MICROBIOL,ST LOUIS,MO 63110.
   WASHINGTON UNIV,SCH MED,HOWARD HUGHES MED INST,DEPT IMMUNOL,ST LOUIS,MO 63110.
   UNIV COLORADO,HLTH SCI CTR,DEPT MICROBIOL IMMUNOL,DENVER,CO 80262.
   UNIV COLORADO,HLTH SCI CTR,CTR CANC,DENVER,CO 80262.
C3 Howard Hughes Medical Institute; Washington University (WUSTL); Washington University (WUSTL); Howard Hughes Medical Institute; Washington University (WUSTL); Howard Hughes Medical Institute; Washington University (WUSTL); Howard Hughes Medical Institute; University of Colorado System; University of Colorado Anschutz Medical Campus; University of Colorado Denver; University of Colorado System; University of Colorado Denver; University of Colorado Anschutz Medical Campus
RP PAWLOWSKI, T (corresponding author), NATL JEWISH CTR IMMUNOL & RESP MED,DEPT MED,1400 JACKSON ST,DENVER,CO 80206, USA.
NR 28
TC 92
Z9 93
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 642
EP 645
DI 10.1038/364642a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100057
PM 8350923
DA 2026-03-10
ER

PT J
AU CHIARELLI, R
   NOVAK, MA
   RASSAT, A
   THOLENCE, JL
AF CHIARELLI, R
   NOVAK, MA
   RASSAT, A
   THOLENCE, JL
TI A FERROMAGNETIC TRANSITION AT 1.48-K IN AN ORGANIC NITROXIDE
SO NATURE
LA English
DT Article
AB IN one of the pioneering studies of magnetism at the microscopic level, Heisenberg1 concluded that ferromagnetism could not exist in compounds consisting only of light elements. A few well defined2 purely organic materials (consisting only of the elements carbon, hydrogen, oxygen and nitrogen) have subsequently been found3-5 to exhibit evidence of ferromagnetic interactions at low temperatures, with a small number of these showing a transition to a true ferromagnetic state. For example, the p-nitrophenyl nitronyl nitroxide radical has a Curie (transition) temperature of 0.60 K (ref. 6), and a possible ferromagnetic transition has been identified7,8 in a C60-based ionic complex. More recently, it was reported9 that the magnetization and magnetic susceptibility behaviour of a crystalline nitroxide biradical, N,N'-dioxy-1,3,5,7-tetramethyl-2,6-diazaadamantane, are indicative of ferromagnetic interactions. Here we report the existence of a ferromagnetic transition in this system, with a Curie temperature of 1.48 +/- 0.02 K. As yet, this is the highest transition temperature found for a purely organic, non-ionic material.
C1 CNRS,CRTBT,F-38042 GRENOBLE,FRANCE.
C3 Centre National de la Recherche Scientifique (CNRS)
RP CHIARELLI, R (corresponding author), ECOLE NORMALE SUPER,24 RUE LHOMOND,F-75231 PARIS 05,FRANCE.
NR 10
TC 491
Z9 513
U1 0
U2 68
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 147
EP 149
DI 10.1038/363147a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100042
DA 2026-03-10
ER

PT J
AU TUCKER, PK
   LUNDRIGAN, BL
AF TUCKER, PK
   LUNDRIGAN, BL
TI RAPID EVOLUTION OF THE SEX-DETERMINING LOCUS IN OLD-WORLD MICE AND RATS
SO NATURE
LA English
DT Article
ID myotonic-dystrophy; determining region; y-chromosome; ctg repeat; fragile-x; gene; sry; instability; expansion; mutation
AB THE Y chromosome-linked sex determining locus (Sry) responsible for testis determination in mammals1-5 contains a DNA-binding motif (HMG box) that is conserved across species of marsupial and placental mammals (infraclasses Metatheria and Eutheria, respectively)1,4,6,7. But little to no sequence similarity is observed in flanking sequences between these two infraclasses, or among orders within each infraclass. We investigated the rate and pattern of evolution for the coding sequence of Sry in Old World mice and rats (subfamily Murinae). We found typical rates of synonymous substitution throughout the gene, but high rates of non-synonymous substitution, especially in the C-terminal (non-HMG box) region, when compared to other genes8. This region is also characterized by a frame-shift mutation and variation in a trinucleotide repeat motif. These data suggest that the non-box region is either functionally unconstrained or has undergone species-specific adaptive divergence.
C1 UNIV MICHIGAN, DEPT BIOL, ANN ARBOR, MI 48109 USA.
C3 University of Michigan System; University of Michigan
RP TUCKER, PK (corresponding author), UNIV MICHIGAN, MUSEUM ZOOL, ANN ARBOR, MI 48109 USA.
NR 27
TC 215
Z9 228
U1 0
U2 11
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 715
EP 717
DI 10.1038/364715a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700057
PM 8355784
DA 2026-03-10
ER

PT J
AU JONES, CP
AF JONES, CP
TI SYSTEMATIC IDENTIFICATION OF CLONE COORDINATES FROM HIGH-DENSITY FILTERS
SO NATURE
LA English
DT Article
ID automated colony picking; library; robotics
AB A system is described for accurately translating the positive signal, obtained after hybridization of high-density colony filters, into clone coordinates. Calibration marks are made on the filter at the same time and in register with the clones. A combination of digitizing tablet and software allows for the retrieval of clone coordinates directly from the autoradiograph.
RP JONES, CP (corresponding author), UNIV CAMBRIDGE,DEPT PATHOL,HUMAN MOLEC GENET RES GRP,TENNIS COURT RD,CAMBRIDGE CB2 1QP,ENGLAND.
NR 12
TC 0
Z9 0
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 369
EP 370
DI 10.1038/365369a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600063
DA 2026-03-10
ER

PT J
AU CONKLIN, BR
   FARFEL, Z
   LUSTIG, KD
   JULIUS, D
   BOURNE, HR
AF CONKLIN, BR
   FARFEL, Z
   LUSTIG, KD
   JULIUS, D
   BOURNE, HR
TI SUBSTITUTION OF 3 AMINO-ACIDS SWITCHES RECEPTOR SPECIFICITY OF G(Q)ALPHA TO THAT OF G(I)ALPHA
SO NATURE
LA English
DT Article
ID g-proteins; adrenergic-receptor; adenylyl cyclase; alpha-subunits; inhibition; rhodopsin; cloning; site; gene; identification
AB AGONIST-BOUND receptors activate heterotrimeric (alphabetagamma) G proteins by catalysing replacement of GDP bound to the alpha-subunit by GTP1-5. Mutations in the C terminus of the alpha-subunit6,7, its covalent modification by pertussis toxin-catalysed ribosylation of ADP8, peptide-specific antibodies directed against it9-11, and peptides mimicking C-terminal sequences12, all inhibit receptor-mediated activation of G proteins. The logical prediction-that specific amino-acid residues at the C-termini of alpha-subunits can determine the abilities of individual G proteins to discriminate among specific subsets of receptors-has so far not been tested experimentally. Different hormone receptors specifically activate G(q) or G(i), whose alpha-subunits (alpha(q) or alpha(i)) stimulate phosphatidylinositol-specific phospholipase C or inhibit adenylyl cyclase, respectively1-5. Here we replace C-terminal amino acids of alpha(q) with the corresponding residues of alpha(i2) to create alpha(q)/alpha(i2) chimaeras that can mediate stimulation of phospholipase C by receptors otherwise coupled exclusively to G(i). A minimum of three alpha(i2) amino acids, including a glycine three residues from the C terminus, suffices to switch the receptor specificity of the alpha(q)/alpha(i2) chimaeras. We propose that a C-terminal turn, centred on this glycine, plays an important part in specifying receptor interactions of G proteins in the G(i)/G(o)/G(z) family.
C1 UNIV CALIF SAN FRANCISCO, DEPT PHARMACOL, S1212 BOX 0450, SAN FRANCISCO, CA 94143 USA.
   TEL AVIV UNIV, CHAIM SHEBA MED CTR, DEPT MED E, IL-52621 TEL AVIV, ISRAEL.
   UNIV CALIF SAN FRANCISCO, DEPT MED, SAN FRANCISCO, CA 94143 USA.
   UNIV CALIF SAN FRANCISCO, PROGRAM CELL BIOL, SAN FRANCISCO, CA 94143 USA.
   UNIV CALIF SAN FRANCISCO, CARDIOVASC RES INST, SAN FRANCISCO, CA 94143 USA.
C3 University of California System; University of California San Francisco; Tel Aviv University; Chaim Sheba Medical Center; University of California System; University of California San Francisco; University of California System; University of California San Francisco; University of California System; University of California San Francisco
NR 37
TC 644
Z9 769
U1 0
U2 18
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 274
EP 276
DI 10.1038/363274a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600056
PM 8387644
DA 2026-03-10
ER

PT J
AU PALLEROS, DR
   REID, KL
   SHI, L
   WELCH, WJ
   FINK, AL
AF PALLEROS, DR
   REID, KL
   SHI, L
   WELCH, WJ
   FINK, AL
TI ATP-INDUCED PROTEIN HSP70 COMPLEX DISSOCIATION REQUIRES K+ BUT NOT ATP HYDROLYSIS
SO NATURE
LA English
DT Article
ID heat-shock proteins; unfolded proteins; dnak; chaperone; binding; groel
AB THE molecular chaperone proteins, particularly Hsp60 and Hsp70, have been implicated in essential cell functions under both normal and stress conditions (reviewed in refs 1-5). Members of the family of heat-shock proteins of M(r) 70K, Hsp70, bind to unfolded proteins and short peptides6-13. Addition of Mg-ATP results in the dissociation of the substrate polypeptides from the chaperone7-11, but as ATP-gammaS (an ATP analogue that is only slowly hydrolysable) cannot substitute for ATP in this reaction7,9,11, it has been concluded that ATP hydrolysis is necessary to dissociate Hsp70-substrate protein complexes. By independently measuring the rates of ATP hydrolysis and substrate protein dissociation, we show here that Mg-ATP binding but not Mg-ATP hydrolysis is essential for substrate dissociation. We also show that there is an absolute requirement for K+ for the effect of Mg-ATP: only the combination of K+ and Mg-ATP will cause the conformational change in Hsp70 that is necessary for substrate dissociation. Moreover, in the absence of K+, Mg-ATP favours complex formation. We consider these results in terms of a G-protein-like model.
C1 UNIV CALIF SANTA CRUZ,DEPT CHEM & BIOCHEM,SANTA CRUZ,CA 95064.
   UNIV CALIF SAN FRANCISCO,DEPT MED,SAN FRANCISCO,CA 94143.
   UNIV CALIF SAN FRANCISCO,DEPT PHYSIOL,SAN FRANCISCO,CA 94143.
C3 University of California System; University of California Santa Cruz; University of California System; University of California San Francisco; University of California System; University of California San Francisco
NR 20
TC 376
Z9 394
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 664
EP 666
DI 10.1038/365664a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600064
PM 8413631
DA 2026-03-10
ER

PT J
AU WIMMER, EA
   JACKLE, H
   PFEIFLE, C
   COHEN, SM
AF WIMMER, EA
   JACKLE, H
   PFEIFLE, C
   COHEN, SM
TI A DROSOPHILA HOMOLOG OF HUMAN SP1 IS A HEAD-SPECIFIC SEGMENTATION GENE
SO NATURE
LA English
DT Article
ID box-binding-proteins; transcriptional activation; empty spiracles; homeobox genes; expression; promoter; domains; repression; sequence; pattern
AB SEGMENTATION in Drosophila is based on a cascade of hierarchical gene interactions initiated by maternally deposited morphogens that define the spatially restricted domains of gap gene expression at blastoderm (reviewed in ref. 1). Although segmentation of the embryonic head is morphologically obscured, the repeated patterns of expression of the segment polarity genes reflect the formation of seven head segments2,3; two of these depend on the segmentation and homeotic genes used in the trunk, whereas the others form as a result of the activity of the head-specific genes orthodenticle (otd), empty spiracles (ems) and buttonhead (btd). The genes ems and otd encode homeodomain proteins. suggesting that they may function as transcription factors4-6. They are expressed in overlapping stripes in the early embryonic head of Drosophila, and their vertebrate homologues, otx and emx, are expressed in overlapping domains in the anterior central nervous system of the mouse embryo7,8. We show here that btd is expressed in a stripe covering the head anlagen of the segments affected in btd lack-of-function mutants and that btd encodes a zinc-finger-type transcription factor with sequence and functional similarity to the prototype mammalian transcription factor Sp1 (ref. 9). When expressed in the spatial pattern of btd, a transgene providing Sp1 activity can support development of the mandibular segment in the head of btd mutant embryos. A ubiquitous transcription factor from humans can therefore replace an essential component of the genetic circuitry required to specify the development of a particular head segment in the fly.
C1 MAX PLANCK INST BIOPHYS CHEM,MOLEK ENTWICKLUNGSBIOL ABT,D-37018 GOTTINGEN,GERMANY.
C3 Max Planck Society
RP WIMMER, EA (corresponding author), BAYLOR COLL MED,HOWARD HUGHES MED INST,DEPT CELL BIOL,HOUSTON,TX 77030, USA.
NR 29
TC 145
Z9 168
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 690
EP 694
DI 10.1038/366690a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500071
PM 8259212
DA 2026-03-10
ER

PT J
AU ATHERTON, MP
   PETFORD, N
AF ATHERTON, MP
   PETFORD, N
TI GENERATION OF SODIUM-RICH MAGMAS FROM NEWLY UNDERPLATED BASALTIC CRUST
SO NATURE
LA English
DT Article
ID archean trondhjemites; subduction-zone; batholith; geochemistry; petrogenesis; lithosphere; tonalites; growth; arcs
AB SODIUM-RICH rocks of trondhjemite-tonalite-dacite (TTD) or -granodiorite (TTG) suites form much of Precambrian continental crust1. They are thought to have formed by partial melting of subducted oceanic crust2,3-a process that would have been much more widespread early in Earth history than at present, owing to the higher thermal gradients prevailing at that time4. Phanerozoic TTD suites do exist, however, and seem also to relate to subduction zones5. Defant and Drummond6 proposed that these suites form where young (<25 Myr), hot oceanic lithosphere is subducted and melts, thus locally simulating the conditions that led to widespread crustal growth in the Archaean. Here we describe plutonic and volcanic rocks from the Cordillera Blanca complex in Peru, which have characteristics of the high-Al TTD suite but which were produced above a subduction zone containing a 60-Myr-old slab. We present evidence that the complex formed by partial melting of newly underplated basaltic crust, and argue that this mechanism should be considered more generally as an additional way of generating sodium-rich arc magmas.
RP ATHERTON, MP (corresponding author), UNIV LIVERPOOL,DEPT EARTH SCI,LIVERPOOL L69 3BX,ENGLAND.
NR 41
TC 1323
Z9 1710
U1 4
U2 169
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 144
EP 146
DI 10.1038/362144a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800055
DA 2026-03-10
ER

PT J
AU FRANCIS, P
   OPPENHEIMER, C
   STEVENSON, D
AF FRANCIS, P
   OPPENHEIMER, C
   STEVENSON, D
TI ENDOGENOUS GROWTH OF PERSISTENTLY ACTIVE VOLCANOS
SO NATURE
LA English
DT Article
AB LAVA lakes and active strombolian vents have persisted at some volcanoes for periods exceeding the historic record. They liberate prodigious amounts of volatiles and thermal energy but erupt little lava, a paradox that raises questions about how volcanoes grow. Although long-lasting surface manifestations can be sustained by convective exchange of magma with deeper reservoirs, residence times of magmas beneath several basaltic volcanoes are approximately 10-100 years1,2, indicating that where surface activity continues for more than 100-1,000 years, the reservoirs are replenished by new magma. Endogenous growth of Kilauea volcano (Hawaii) through dyke intrusion and cumulate formation is a well-understood consequence of the steady supply of mantle-derived magma3,4. As we show here, inferred heat losses from the Halemaumau lava lake indicate a period of dominantly endogenous growth of Kilauea volcano during the nineteenth century. Moreover, heat losses and degassing rates for several other volcanoes, including Stromboli, also indicate cryptic influxes of magma that far exceed visible effluxes of lavas. We propose that persistent activity at Stromboli, and at other volcanoes in different tectonic settings, is evidence of endogenous growth, involving processes similar to those at Kilauea.
C1 OPEN UNIV, DEPT EARTH SCI, MILTON KEYNES MK7 6AA, BUCKS, ENGLAND.
C3 Open University - UK
RP FRANCIS, P (corresponding author), UNIV HAWAII, DIV PLANETARY GEOSCI, 2525 CORREA RD, HONOLULU, HI 96822 USA.
NR 34
TC 175
Z9 186
U1 0
U2 14
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 554
EP 557
DI 10.1038/366554a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800066
DA 2026-03-10
ER

PT J
AU WYSS, AR
   FLYNN, JJ
   NORELL, MA
   SWISHER, CC
   CHARRIER, R
   NOVACEK, MJ
   MCKENNA, MC
AF WYSS, AR
   FLYNN, JJ
   NORELL, MA
   SWISHER, CC
   CHARRIER, R
   NOVACEK, MJ
   MCKENNA, MC
TI SOUTH-AMERICA EARLIEST RODENT AND RECOGNITION OF A NEW INTERVAL OF MAMMALIAN EVOLUTION
SO NATURE
LA English
DT Article
ID geochronology; constants; ages
AB THE mid-Cenozoic immigration of rodents and primates to South America (when it was widely isolated by oceans) represents a pre-eminent problem in the biogeographical history of placental mammals. The unexpected discovery of South America's earliest rodent in the central Chilean Andes provides information critical to resolving the source area and primitive morphology of South American caviomorphs, suggesting an African origin for the group. This rodent is part of a new fossil mammal fauna1, the first diverse assemblage known for a critical 15-25 million year gap in the fossil record. We report here that co-occurrence of numerous higher-level taxa otherwise restricted to older or younger intervals identifies this fauna as representing a new biochronological interval preceding the Deseadan (South American Land Mammal Age), previously the earliest occurrence of rodents and primates on the continent. Radioisotopic dating corroborates biostratigraphy in identifying the new Andean rodent as the earliest known from the continent.
C1 FIELD MUSEUM NAT HIST, DEPT GEOL, CHICAGO, IL 60605 USA.
   INST HUMAN ORIGINS, CTR GEOCHRONOL, BERKELEY, CA 94709 USA.
   UNIV CHILE, FAC CIENCIAS FIS & MATEMAT, DEPT GEOL, SANTIAGO, CHILE.
   AMER MUSEUM NAT HIST, DEPT VERTEBRATE PALEONTOL, NEW YORK, NY 10024 USA.
C3 Field Museum of Natural History (Chicago); Universidad de Chile; American Museum of Natural History (AMNH)
RP WYSS, AR (corresponding author), UNIV CALIF SANTA BARBARA, DEPT GEOL SCI, SANTA BARBARA, CA 93106 USA.
NR 32
TC 138
Z9 154
U1 1
U2 11
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 434
EP 437
DI 10.1038/365434a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300054
DA 2026-03-10
ER

PT J
AU PARK, HO
   CHANT, J
   HERSKOWITZ, I
AF PARK, HO
   CHANT, J
   HERSKOWITZ, I
TI BUD2 ENCODES A GTPASE-ACTIVATING PROTEIN FOR BUD1/RSR1 NECESSARY FOR PROPER BUD-SITE SELECTION IN YEAST
SO NATURE
LA English
DT Article
ID saccharomyces-cerevisiae; ras gtpase; cell polarity; gene; pathway; ira2; gap; purification; regulator; exchange
AB CELLS of the budding yeast Saccharomyces cerevisiae bud at either axial or bipolar sites depending on their cell type1. Bud-site selection directs both cell polarity and the cytoskeletal orientation during budding and is determined by at least five genes: BUD1/RSR1, BUD2, BUD3, BUD4 and BUD52-4. Mutants defective in BUD1, BUD2 or BUD5 choose bud sites randomly. Bud1 protein (Bud1p) has sequence similarity to Ras, a small GTP-binding protein, and Bud5p is similar to Cdc25p (refs 4, 5), a GDP-GTP exchange factor6. Here we report that Bud2p is a GTPase-activating protein (GAP) for Bud1p with a sequence similar to the catalytic domain of rasGAPs, and that Bud2p purified from yeast stimulates GTP hydrolysis by Bud1p. Chromosomal deletion of BUD2 causes a random budding pattern but no obvious growth defect. Overexpression of BUD2 also causes a random budding pattern by wild-type cells11.
C1 UNIV CALIF SAN FRANCISCO, DEPT BIOCHEM & BIOPHYS, PROGRAM GENET, SAN FRANCISCO, CA 94143 USA.
   UNIV CALIF SAN FRANCISCO, PROGRAM CELL BIOL, SAN FRANCISCO, CA 94143 USA.
C3 University of California System; University of California San Francisco; University of California System; University of California San Francisco
NR 27
TC 153
Z9 181
U1 1
U2 2
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 269
EP 274
DI 10.1038/365269a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100060
PM 8371782
DA 2026-03-10
ER

PT J
AU ZHANG, SN
   FISHMAN, GJ
   HARMON, BA
   PACIESAS, WS
AF ZHANG, SN
   FISHMAN, GJ
   HARMON, BA
   PACIESAS, WS
TI IMAGING HIGH-ENERGY ASTROPHYSICAL SOURCES USING EARTH OCCULTATION
SO NATURE
LA English
DT Article
ID x-ray; galactic-center; aperture synthesis; astronomy
AB HIGH-ENERGY astrophysical sources can be difficult to image.  Photons with energies above approximately 5 keV are hard to focus, so experiments usually employ coded masks1-4 or moving collimators5-9 to modulate the flux received by the detectors; the resulting signals are then deconvolved to form the images. Here we demonstrate a new approach which makes use of the large-area, non-collimated detectors of the Burst and Transient Source Experiment on the Compton Gamma-Ray Observatory. As the spacecraft moves in its orbit, the Earth itself acts as a stable occulting disk. Changes in the measured signal during a single occultation correspond to the integrated intensity of sources positioned along the arc described by the Earth's edge (limb).  The low-altitude, moderately inclined orbit of the spacecraft ensures that the angle at which the limb traverses a source region varies between occultations, and thus data from a series of occultations can be transformed into an image. This imaging process is conceptually and mathematically similar to those used in fan-beam aperture-synthesis radio-astronomy10 and medical computer-assisted tomography11, and holds great promise for all-sky imaging with relatively simple (and hence inexpensive) detectors.
C1 UNIV SPACE RES ASSOC,HUNTSVILLE,AL 35806.
   UNIV ALABAMA,HUNTSVILLE,AL 35899.
C3 Universities Space Research Association (USRA); University of Alabama System; University of Alabama Huntsville
RP ZHANG, SN (corresponding author), NASA,GEORGE C MARSHALL SPACE FLIGHT CTR,CODE ES66,HUNTSVILLE,AL 35812, USA.
NR 29
TC 45
Z9 50
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 245
EP 247
DI 10.1038/366245a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500056
DA 2026-03-10
ER

PT J
AU YOUNGSON, C
   NURSE, C
   YEGER, H
   CUTZ, E
AF YOUNGSON, C
   NURSE, C
   YEGER, H
   CUTZ, E
TI OXYGEN SENSING IN AIRWAY CHEMORECEPTORS
SO NATURE
LA English
DT Article
ID neuro-epithelial body; rat carotid-body; membrane patches; cytochrome-b; po2 sensor; l-dopa; cells; lung; hypoxia; localization
AB PULMONARY neuroepithelial bodies, composed of innervated clusters of amine- and peptide-containing cells, are widely distributed throughout the airway mucosa of human and animal lungs1-3. Structurally, neuroepithelial bodies resemble chemoreceptors (such as carotid body, taste buds) and are thought to function as hypoxia-sensitive airway sensors4. Evidence for this is indirect, however, and the mechanism of oxygen sensing by these cells is unknown. Here we culture neuroepithelial bodies isolated from rabbit fetal lungs and identify voltage-activated potassium, calcium and sodium currents using the whole-cell patch clamp technique. Upon exposure to hypoxia there is a reversible reduction (25-30%) in the outward potassium current, with no change in inward currents. In addition, we demonstrate the expression of an oxygen-binding protein (b-cytochrome, NADPH oxidase) on the plasma membrane of these cells. The identification of an oxygen-sensing mechanism (namely the presence of an O2-sensitive potassium channel coupled to an O2 sensor protein5) in the cells of pulmonary neuroepithelial bodies indicates that they are transducers of the hypoxia stimulus and hence may function as airway chemoreceptors in the regulation of respiration.
C1 HOSP SICK CHILDREN, RES INST, DEPT PATHOL, 555 UNIV AVE, TORONTO M5G 1X8, ONTARIO, CANADA.
   MCMASTER UNIV, DEPT BIOL, HAMILTON L8S 4K1, ONTARIO, CANADA.
   UNIV TORONTO, TORONTO M5S 1A1, ONTARIO, CANADA.
C3 University of Toronto; Hospital for Sick Children (SickKids); McMaster University; University of Toronto
NR 27
TC 404
Z9 427
U1 0
U2 33
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 153
EP 155
DI 10.1038/365153a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200046
PM 8371757
DA 2026-03-10
ER

PT J
AU MURAI, S
   KAKIUCHI, F
   SEKINE, S
   TANAKA, Y
   KAMATANI, A
   SONODA, M
   CHATANI, N
AF MURAI, S
   KAKIUCHI, F
   SEKINE, S
   TANAKA, Y
   KAMATANI, A
   SONODA, M
   CHATANI, N
TI EFFICIENT CATALYTIC ADDITION OF AROMATIC CARBON-HYDROGEN BONDS TO OLEFINS
SO NATURE
LA English
DT Article
ID c-h bonds; activation; cyclometalation; complexes; alkanes
AB The selective cleavage of carbon-hydrogen bonds in organic compounds is a critical step in many organic syntheses, and is particularly important in the conversion of hydrocarbons to useful organic compounds. An organometallic ruthenium complex can cleave C-H bonds in a variety of aromatic systems, leading to addition to alkenes by C-C bond formation. The catalyst operates with a degree of efficiency, selectivity and generality that will make it extremely valuable in organic synthesis.
RP MURAI, S (corresponding author), OSAKA UNIV,FAC ENGN,DEPT APPL CHEM,SUITA,OSAKA 565,JAPAN.
NR 18
TC 1265
Z9 1395
U1 5
U2 255
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 529
EP 531
DI 10.1038/366529a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800059
DA 2026-03-10
ER

PT J
AU CHELAZZI, L
   MILLER, EK
   DUNCAN, J
   DESIMONE, R
AF CHELAZZI, L
   MILLER, EK
   DUNCAN, J
   DESIMONE, R
TI A NEURAL BASIS FOR VISUAL-SEARCH IN INFERIOR TEMPORAL CORTEX
SO NATURE
LA English
DT Article
ID superior colliculus; single units; attention; features; neurons; monkey
AB WE often search for a face in a crowd or for a particular object in a cluttered environment. In this type of visual search, memory interacts with attention: the mediating neural mechanisms should include a stored representation of the object and a means for selecting that object from among others in the scene1-4. Here we test whether neurons in inferior temporal cortex, an area known to be important for high-level visual processing, might provide these components. Monkeys were presented with a complex picture (the cue) to hold in memory during a delay period. The cue initiated activity that persisted through the delay among the neurons that were tuned to its features. The monkeys were then given 2-5 choice pictures and were required to make an eye movement to the one (the target) that matched the cue. About 90-120 milliseconds before the onset of the eye movement to the target, responses to non-targets were suppressed and the neuronal response was dominated by the target. The results suggest that inferior temporal cortex is involved in selecting the objects to which we attend and foveate.
C1 MRC,APPL PSYCHOL UNIT,CAMBRIDGE CB2 2EF,ENGLAND.
C3 University of Cambridge
RP CHELAZZI, L (corresponding author), NIMH,NEUROPSYCHOL LAB,BLDG 9,ROOM 1E104,BETHESDA,MD 20892, USA.
NR 13
TC 862
Z9 978
U1 3
U2 54
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 345
EP 347
DI 10.1038/363345a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700051
PM 8497317
DA 2026-03-10
ER

PT J
AU COLE, DG
   CHINN, SW
   WEDAMAN, KP
   HALL, K
   VUONG, T
   SCHOLEY, JM
AF COLE, DG
   CHINN, SW
   WEDAMAN, KP
   HALL, K
   VUONG, T
   SCHOLEY, JM
TI NOVEL HETEROTRIMERIC KINESIN-RELATED PROTEIN PURIFIED FROM SEA-URCHIN EGGS
SO NATURE
LA English
DT Article
ID driven microtubule motility; heavy-chain; peptide antibody; mitotic apparatus; light-chains; identification; localization; sequence; atpase
AB KINESIN heavy chain and kinesin-related polypeptides (KRPs) comprise a family of motor proteins with diverse intracellular transport functions1-7. Using pan-kinesin peptide antibodies that react with these proteins8,9, we have previously purified from sea urchin eggs a trimeric microtubule-binding and bundling protein, KRP(85/95) (ref. 8) comprising subunits of M(r) 115,000 (115K), 95K and 85K. We report here that kinesin-related genes encode the 85K and 95K subunits, and that the protein can be immunoprecipitated from cytosol as a trimeric complex using an 85K monoclonal antibody. We also find that purified KRP(85/95) directs movements towards the 'plus' ends of microtubules. To our knowledge, this protein is the first kinesin-related motor to be purified from its natural host cell in a native multimeric state.
C1 UNIV CALIF DAVIS,DIV BIOL SCI,MOLEC & CELLULAR BIOL SECT,DAVIS,CA 95616.
C3 University of California System; University of California Davis
NR 22
TC 229
Z9 282
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 268
EP 270
DI 10.1038/366268a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500064
PM 8232586
DA 2026-03-10
ER

PT J
AU MOORE, MS
   BLOBEL, G
AF MOORE, MS
   BLOBEL, G
TI THE GTP-BINDING PROTEIN RAN/TC4 IS REQUIRED FOR PROTEIN IMPORT INTO THE NUCLEUS
SO NATURE
LA English
DT Article
ID premature chromosome condensation; saccharomyces-cerevisiae; gene rcc1; regulator; inhibition; cells; dna; translocation; mutation; mitosis
AB Two cytosolic fractions (A and B) from Xenopus oocytes are sufficient to support protein import into the nuclei of digitonin-permeabilized cells1. Fraction A recognizes the nuclear localization sequence (NLS) and binds the import substrate to the nuclear envelope, whereas fraction B mediates the subsequent passage of the bound substrate into the nucleus. Here we report that two interacting components are required for full fraction-B activity, purify one of these components to homogeneity, and show that it is the highly abundant GTP-binding protein Ran (Ras-related nuclear protein)/TC4.
RP MOORE, MS (corresponding author), ROCKEFELLER UNIV,HOWARD HUGHES MED INST,CELL BIOL LAB,1230 YORK AVE,NEW YORK,NY 10021, USA.
NR 26
TC 705
Z9 759
U1 1
U2 30
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 661
EP 663
DI 10.1038/365661a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600063
PM 8413630
DA 2026-03-10
ER

PT J
AU SAGAN, C
   THOMPSON, WR
   CARLSON, R
   GURNETT, D
   HORD, C
AF SAGAN, C
   THOMPSON, WR
   CARLSON, R
   GURNETT, D
   HORD, C
TI A SEARCH FOR LIFE ON EARTH FROM THE GALILEO SPACECRAFT
SO NATURE
LA English
DT Article
ID spectrometer experiment
AB In its December 1990 fly-by of Earth, the Galileo spacecraft found evidence of abundant gaseous oxygen, a widely distributed surface pigment with a sharp absorption edge in the red part of the visible spectrum, and atmospheric methane in extreme thermodynamic disequilibrium; together, these are strongly suggestive of life on Earth. Moreover, the presence of narrow-band, pulsed, amplitude-modulated radio transmission seems uniquely attributable to intelligence. These observations constitute a control experiment for the search for extraterrestrial life by modern interplanetary spacecraft.
C1 JET PROP LAB,ATMOSPHER & COMETARY SCI SECT,PASADENA,CA 91109.
   UNIV IOWA,DEPT PHYS & ASTRON,IOWA CITY,IA 52242.
   UNIV COLORADO,ATMOSPHER & SPACE PHYS LAB,BOULDER,CO 80309.
C3 National Aeronautics & Space Administration (NASA); NASA Jet Propulsion Laboratory (JPL); University of Iowa; University of Colorado System; University of Colorado Boulder
RP SAGAN, C (corresponding author), CORNELL UNIV,PLANETARY STUDIES LAB,ITHACA,NY 14853, USA.
NR 34
TC 326
Z9 362
U1 3
U2 64
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 715
EP 721
DI 10.1038/365715a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200051
PM 11536539
DA 2026-03-10
ER

PT J
AU MCDONOUGH, WF
   IRELAND, TR
AF MCDONOUGH, WF
   IRELAND, TR
TI INTRAPLATE ORIGIN OF KOMATIITES INFERRED FROM TRACE-ELEMENTS IN GLASS INCLUSIONS
SO NATURE
LA English
DT Article
ID belingwe greenstone-belt; basalts; mantle; petrogenesis; constraints; evolution; zimbabwe; rhodesia; volcano; hawaii
AB THE relative abundances of immobile elements (such as calcium, aluminium, titanium, zirconium and the rare-earth elements) in the Archaean ultramafic lavas known as komatiites have provided important information about the composition of the early Earth's mantle, but to establish the origin and tectonic setting of these lavas one also needs the abundances of mobile elements, such as the alkali metals, alkaline-earth elements, and uranium and lead. Up to now, it has not been possible to use these elements in constraining komatiite petrogenesis, because of the pervasive effects of alteration in these ancient lavas; recently, however, some remarkably fresh, 2.7-Gyr-old komatiites have been discovered, which contain unaltered olivine crystals and small glass inclusions1. We report ion micoprobe data for 25 trace elements from these glass inclusions, and show that the ratios of mobile to immobile incompatible elements are similar to those found in modern intraplate basalts, and distinct from modern mid-ocean-ridge and convergent-margin basalts. We infer that these Archaean magmas formed from sources similar to (or slightly depleted relative to) those of modern intraplate basalts, supporting the suggestion2,3 that komatiites are ancient analogues of modern plume-related magmas.
RP MCDONOUGH, WF (corresponding author), AUSTRALIAN NATL UNIV,RES SCH EARTH SCI,CANBERRA,ACT 0200,AUSTRALIA.
NR 22
TC 93
Z9 95
U1 1
U2 34
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 432
EP 434
DI 10.1038/365432a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300053
DA 2026-03-10
ER

PT J
AU KHAVARI, PA
   PETERSON, CL
   TAMKUN, JW
   MENDEL, DB
   CRABTREE, GR
AF KHAVARI, PA
   PETERSON, CL
   TAMKUN, JW
   MENDEL, DB
   CRABTREE, GR
TI BRG1 CONTAINS A CONSERVED DOMAIN OF THE SWI2/SNF2 FAMILY NECESSARY FOR NORMAL MITOTIC GROWTH AND TRANSCRIPTION
SO NATURE
LA English
DT Article
ID yeast saccharomyces-cerevisiae; putative helicases; global activator; gene-expression; proteins; drosophila; snf2/swi2; encodes; repair; swi1
AB SEQUENCE-SPECIFIC DNA binding activators of gene transcription may be assisted by SWI2(SNF2)1,2, which contains a DNA-dependent ATPase domain3. We have isolated a human complementary, DNA encoding a 205K nuclear protein, BRG1, that contains extensive homology to SWI2 and Drosophila brahma4,5. We report here that a SWI2/BRG1 chimaera with the DNA-dependent ATPase domain replaced by corresponding human sequence restored normal mitotic growth and capacity for transcriptional activation to swi2- yeast cells. Point mutation of the conserved ATP binding site lysine abolished this complementation. This mutation in SW12 exerted a dominant negative effect on transcription in yeast. A lysine to arginine substitution at the corresponding residue of BRG1 also generated a transcriptional dominant negative in human cells. BRG1 is exclusively nuclear and present in a high M(r) complex of about 2 x 10(6). These results show that the SWI2 family DNA-dependent ATPase domain has functional conservation between yeast and humans and suggest that a SWI/SNF protein complex is required for the activation of selective mammalian genes.
C1 STANFORD UNIV, BECKMAN CTR MOLEC & GENET MED, HOWARD HUGHES MED INST, B211 HHMI, STANFORD, CA 94305 USA.
   UNIV MASSACHUSETTS, MED CTR, PROGRAM MOLEC MED, WORCESTER, MA 01650 USA.
   UNIV CALIF SANTA CRUZ, DEPT BIOL, SANTA CRUZ, CA 95064 USA.
C3 Stanford University; Howard Hughes Medical Institute; University of Massachusetts System; University of Massachusetts Worcester; University of California System; University of California Santa Cruz
NR 31
TC 580
Z9 665
U1 0
U2 17
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 170
EP 174
DI 10.1038/366170a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600061
PM 8232556
DA 2026-03-10
ER

PT J
AU RODER, H
   HAHN, E
   BRUNE, H
   BUCHER, JP
   KERN, K
AF RODER, H
   HAHN, E
   BRUNE, H
   BUCHER, JP
   KERN, K
TI BUILDING ONE-DIMENSIONAL AND 2-DIMENSIONAL NANOSTRUCTURES BY DIFFUSION-CONTROLLED AGGREGATION AT SURFACES
SO NATURE
LA English
DT Article
ID microscope; growth; films
AB THE formation of nanometre-scale surface structures by atomic manipulation with the scanning tunneling microscope has opened up opportunities for creating new metastable states of matter atom by atom1. The technique allows the fabrication of arbitrary structures, but its application may be limited by considerations of speed, as only one nanostructure can be built at a time. Here we describe the simultaneous formation of many densely packed nanostructures of various morphologies using diffusion-controlled aggregation on surfaces. By exploiting the dependence of the mobility of adsorbed atoms on substrate crystal face and temperature, we are able to grow linear, two-dimensional or tenuous fractal aggregates of nanometre dimensions. The high number density (10(11)-10(14) cm-2) of these structures means that their physical and chemical properties can be easily measured with conventional surface spectroscopies.
RP RODER, H (corresponding author), ECOLE POLYTECH FED LAUSANNE, INST PHYS EXPTL, CH-1015 LAUSANNE, SWITZERLAND.
NR 19
TC 451
Z9 471
U1 2
U2 119
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 141
EP 143
DI 10.1038/366141a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600051
DA 2026-03-10
ER

PT J
AU LLEDO, PM
   VERNIER, P
   VINCENT, JD
   MASON, WT
   ZOREC, R
AF LLEDO, PM
   VERNIER, P
   VINCENT, JD
   MASON, WT
   ZOREC, R
TI INHIBITION OF RAB3B EXPRESSION ATTENUATES CA2+-DEPENDENT EXOCYTOSIS IN RAT ANTERIOR-PITUITARY-CELLS
SO NATURE
LA English
DT Article
ID gtp-binding protein; membrane capacitance; bovine lactotrophs; synthetic peptides; endocytic pathway; chromaffin cells; secretion; brain; domain; melanotrophs
AB LOW-MOLECULAR-WEIGHT GTP-binding proteins (small G proteins) of the Rab family have been proposed to act as central regulators of vesicular traffic1,2, and proteins of the Rab3 subfamily (Rab3A, B, C and D)3-6 are thought to be,associated with membrane vesicles or granules undergoing exocytotic fusion with the plasma membrane7-10. Rab3A is highly expressed in brain11, whereas Rab3B is the major form found in rat anterior pituitary gland. We report here that antisense oligonucleotides against Rab3B, introduced into pituitary cells using the whole-cell patch clamp technique, specifically and reversibly block expression of Rab3B. We find that calcium-dependent exocytosis is inhibited without affecting endocytosis. Antisense oligonucleotides directed against Rab3A have no effect. Our results indicate that Rab3B is likely to be a key intracellular signalling molecule which can control exocytosis downstream of other calcium-dependent processes in anterior pituitary cells.
C1 INST A FESSARD,CNRS,F-91198 GIF SUR YVETTE,FRANCE.
   UNIV LJUBLJANA FAC MED,INST PATHOPHYSIOL,61105 LJUBLJANA,SLOVENIA.
C3 Centre National de la Recherche Scientifique (CNRS); Universite Paris Saclay; University of Ljubljana
RP LLEDO, PM (corresponding author), AFRC,BABRAHAM INST,DEPT NEUROBIOL,CAMBRIDGE CB2 4AT,ENGLAND.
FU Wellcome Trust Funding Source: Medline
NR 36
TC 189
Z9 196
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 540
EP 544
DI 10.1038/364540a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700059
PM 8393147
DA 2026-03-10
ER

PT J
AU MASU, Y
   WOLF, E
   HOLTMANN, B
   SENDTNER, M
   BREM, G
   THOENEN, H
AF MASU, Y
   WOLF, E
   HOLTMANN, B
   SENDTNER, M
   BREM, G
   THOENEN, H
TI DISRUPTION OF THE CNTF GENE RESULTS IN MOTOR-NEURON DEGENERATION
SO NATURE
LA English
DT Article
ID ciliary neurotrophic factor; type-2 astrocyte development; cholinergic differentiation; neuronotrophic factor; regional distribution; factor prevents; messenger-rna; growth-factor; spinal-cord; rat-brain
AB CNTF is a cytosolic molecule expressed postnatally in myelinating Schwann cells and in a subpopulation of astrocytes. Although CNTF administration prevents lesion-mediated and genetically determined motor neuron degeneration, its physiological function remained elusive. Here it is reported that abolition of CNTF gene expression by homologous recombination results in a progressive atrophy and loss of motor neurons in adult mice, which is functionally reflected by a small but significant reduction in muscle strength.
C1 LUDWIG MAXIMILIANS UNIV MUNCHEN, INST MOLEK TIERZUCHT, D-80539 MUNICH, GERMANY.
C3 University of Munich
RP MASU, Y (corresponding author), MAX PLANCK INST PSYCHIAT, NEUROCHEM ABT, KLOPFERSPITZ 18A, D-82152 MARTINSRIED, GERMANY.
NR 38
TC 547
Z9 603
U1 0
U2 2
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 27
EP 32
DI 10.1038/365027a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600043
PM 8361533
DA 2026-03-10
ER

PT J
AU KAUFMAN, DL
   CLARESALZLER, M
   TIAN, JD
   FORSTHUBER, T
   TING, GSP
   ROBINSON, P
   ATKINSON, MA
   SERCARZ, EE
   TOBIN, AJ
   LEHMANN, PV
AF KAUFMAN, DL
   CLARESALZLER, M
   TIAN, JD
   FORSTHUBER, T
   TING, GSP
   ROBINSON, P
   ATKINSON, MA
   SERCARZ, EE
   TOBIN, AJ
   LEHMANN, PV
TI SPONTANEOUS LOSS OF T-CELL TOLERANCE TO GLUTAMIC-ACID DECARBOXYLASE IN MURINE INSULIN-DEPENDENT DIABETES
SO NATURE
LA English
DT Article
ID heat-shock protein; autoantigen; mouse; gamma; cd4+; encephalomyelitis; autoantibody; identification; autoimmunity; induction
AB INSULIN-DEPENDENT diabetes mellitus (IDDM) in non-obese diabetic (NOD) mice results from the T-lymphocyte-mediated destruction of the insulin-producing pancreatic beta-cells and serves as a model for human IDDM1.  Whereas a number of autoantibodies are associated with IDDM2, it is unclear when and to what beta-cell antigens pathogenic T cells become activated during the disease process. We report here that a T-helper-1 (Th1) response to glutamate decarboxylase develops in NOD mice at the same time as the onset of insulitis. This response is initially limited to a confined region of glutamate decarboxylase, but later spreads intramolecularly to additional determinants. Subsequently, T-cell reactivity arises to other beta-cell antigens, consistent with intermolecular diversification of the response. Prevention of the spontaneous anti-glutamate decarboxylase response, by tolerization of glutamate decarboxylase-reactive T cells, blocks the development of T-cell autoimmunity to other beta-cell antigens, as well as insulitis and diabetes. Our data suggest that (1) glutamate decarboxylase is a key target antigen in the induction of murine IDDM; (2) autoimmunity to glutamate decarboxylase triggers T-cell responses to other beta-cell antigens, and (3) spontaneous autoimmune disease can be prevented by tolerization to the initiating target antigen.
C1 UNIV CALIF LOS ANGELES,DEPT MED,LOS ANGELES,CA 90024.
   UNIV CALIF LOS ANGELES,DEPT MICROBIOL & MOLEC GENET,LOS ANGELES,CA 90024.
   UNIV CALIF LOS ANGELES,DEPT BIOL,LOS ANGELES,CA 90024.
   UNIV CALIF LOS ANGELES,BRAIN RES INST,LOS ANGELES,CA 90024.
   UNIV CALIF LOS ANGELES,INST MOLEC BIOL,LOS ANGELES,CA 90024.
   UNIV FLORIDA,COLL MED,DEPT PATHOL & LAB MED,GAINESVILLE,FL 32610.
C3 University of California System; University of California Los Angeles; University of California System; University of California Los Angeles; University of California System; University of California Los Angeles; University of California System; University of California Los Angeles; University of California System; University of California Los Angeles; State University System of Florida; University of Florida
RP KAUFMAN, DL (corresponding author), UNIV CALIF LOS ANGELES,DEPT PSYCHIAT & BIOBEHAV SCI,LOS ANGELES,CA 90024, USA.
FU NINDS NIH HHS [R01 NS022256] Funding Source: Medline
NR 29
TC 1048
Z9 1134
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 69
EP 72
DI 10.1038/366069a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700056
PM 7694152
DA 2026-03-10
ER

PT J
AU REX, MA
   STUART, CT
   HESSLER, RR
   ALLEN, JA
   SANDERS, HL
   WILSON, GDF
AF REX, MA
   STUART, CT
   HESSLER, RR
   ALLEN, JA
   SANDERS, HL
   WILSON, GDF
TI GLOBAL-SCALE LATITUDINAL PATTERNS OF SPECIES-DIVERSITY IN THE DEEP-SEA BENTHOS
SO NATURE
LA English
DT Article
ID community; fauna; atlantic; ocean
AB LATITUDINAL gradients of species diversity are ubiquitous features of terrestrial and coastal marine biotas, and they have inspired the development of theoretical ecology1-3. Since the discovery of high species diversity in the deep-sea benthos4, much has been learned about local5,6 and regional7-9 patterns of diversity. Variation in diversity on larger scales remains poorly described. Latitudinal gradients of diversity were unexpected because it was assumed that the environmental gradients that cause large-scale patterns in surface environments could not affect communities living at great depths10. Here we report that deep-sea bivalves, gastropods and isopods show clear latitudinal diversity gradients in the North Atlantic, and strong interregional variation in the South Atlantic. Many seemingly incompatible mechanisms have been proposed to explain deep-sea species diversity11. The existence of regular global patterns suggests that these mechanisms operate at different spatial and temporal scales.
C1 UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, LA JOLLA, CA 92093 USA.
   UNIV MARINE BIOL STN, MILLPORT KA28 0EG, SCOTLAND.
   WOODS HOLE OCEANOG INST, WOODS HOLE, MA 02543 USA.
   AUSTRALIAN MUSEUM, SYDNEY, NSW 2000, AUSTRALIA.
C3 University of California System; University of California San Diego; Scripps Institution of Oceanography; Woods Hole Oceanographic Institution; Australian Museum
RP REX, MA (corresponding author), UNIV MASSACHUSETTS, DEPT BIOL, BOSTON, MA 02125 USA.
NR 41
TC 356
Z9 376
U1 0
U2 64
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 636
EP 639
DI 10.1038/365636a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600055
DA 2026-03-10
ER

PT J
AU REINER, O
   CARROZZO, R
   SHEN, Y
   WEHNERT, M
   FAUSTINELLA, F
   DOBYNS, WB
   CASKEY, CT
   LEDBETTER, DH
AF REINER, O
   CARROZZO, R
   SHEN, Y
   WEHNERT, M
   FAUSTINELLA, F
   DOBYNS, WB
   CASKEY, CT
   LEDBETTER, DH
TI ISOLATION OF A MILLER-DIEKER LISSENCEPHALY GENE CONTAINING G-PROTEIN BETA-SUBUNIT-LIKE REPEATS
SO NATURE
LA English
DT Article
ID molecular dissection; sequence; yeast; deletions; cloning; region
AB LISSENCEPHALY (agyria-pachygyria) is a human brain malformation manifested by a smooth cerebral surface and abnormal neuronal migration1,2. Identification of the gene(s) involved in this disorder would facilitate molecular dissection of normal events in brain development3. Type 1 lissencephaly occurs either as an isolated abnormality or in association with dysmorphic facial appearance in patients with Miller-Dieker syndrome4,5. About 15% of patients with isolated lissencephaly and more than 90% of patients with Miller-Dieker syndrome have microdeletions in a critical 350-kilobase region in chromosome 17p13.3 (ref. 6). These deletions are hemizygous, so haplo-insufficiency for a gene in this interval is implicated. Here we report the cloning of a gene (LIS-1, lissencephaly-1) in 17p13.3 that is deleted in Miller-Dieker patients. Non-overlapping deletions involving either the 5' or 3' end of the gene were found in two patients, identifying LIS-1 as the disease gene. The deduced amino-acid sequence shows significant homology to beta-subunits of heterotrimeric G proteins, suggesting that it could possibly be involved in a signal transduction pathway crucial for cerebral development.
C1 BAYLOR COLL MED,INST MOLEC GENET,HOUSTON,TX 77030.
   BAYLOR COLL MED,HOWARD HUGHES MED INST,HOUSTON,TX 77030.
   UNIV MINNESOTA,SCH MED,DEPT NEUROL,DIV PEDIAT NEUROL,MINNEAPOLIS,MN 55455.
   UNIV MINNESOTA,SCH MED,DEPT PEDIAT,MINNEAPOLIS,MN 55455.
C3 Baylor College of Medicine; Howard Hughes Medical Institute; Baylor College of Medicine; University of Minnesota System; University of Minnesota Twin Cities; University of Minnesota System; University of Minnesota Twin Cities
NR 29
TC 898
Z9 1021
U1 0
U2 27
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 717
EP 721
DI 10.1038/364717a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700058
PM 8355785
DA 2026-03-10
ER

PT J
AU STANLEY, DJ
   WARNE, AG
AF STANLEY, DJ
   WARNE, AG
TI SEA-LEVEL AND INITIATION OF PREDYNASTIC CULTURE IN THE NILE DELTA
SO NATURE
LA English
DT Article
ID late quaternary
AB PREDYNASTIC occupation of the Nile valley and delta, dating back to at least 5000 BC, has been attributed by most archaeologists to environmental factors, primarily regional climate change and fluctuating Nile flood stages1-5. Here we propose instead that initiation of farming settlements in the Nile delta was closely related to eustatic sea level. We present geological analyses of late Quaternary subsurface sections throughout the delta which reveal that the deceleration in sea-level rise that occurred at about 6500-5500 BC was a prime factor in the accumulation of Nile silt, and the creation of the widespread and fertile delta plain. As rising sea level reduced the gradient of the river course, a system of meandering Nile distributaries evolved, with increased overbank deposition burying the former (early Holocene), partially vegetated sandy plain. The broadening, seasonally flooded, fecund plain, with its increasing plant cover, provided a setting that was conducive to evolving agricultural activity and was therefore instrumental in the development of Predynastic communities in the Nile delta.
RP STANLEY, DJ (corresponding author), SMITHSONIAN INST,MEDITERRANEAN BASIN PROGRAM,PALEOBIOL E-207 NMNH,WASHINGTON,DC 20560, USA.
NR 30
TC 71
Z9 83
U1 0
U2 16
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 435
EP 438
DI 10.1038/363435a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800054
DA 2026-03-10
ER

PT J
AU YEMANE, K
AF YEMANE, K
TI CONTRIBUTION OF LATE PERMIAN PALEOGEOGRAPHY IN MAINTAINING A TEMPERATE CLIMATE IN GONDWANA
SO NATURE
LA English
DT Article
ID canada; indicators; africa; lakes
AB NUMERICAL simulations based on general circulation and energy-balance models consistently indicate that. the high latitudes of Gondwana experienced seasonal extremes in climate during the Late Permian period1-3. But palaeogeographic maps based on the distribution of climate-sensitive rocks4, palynological and palaeobotanical data5,6 and dicynodont fossil records7 all imply a temperate climate. The reason for this discrepancy has not been clear. Recently, it has emerged from studies of Upper Permian fluviolacustrine deposits throughout southern Africa that the geography was dominated by a series of giant lakes, perhaps interconnected within major fluvial frameworks8. Here I review these data and their implications for a temperate climate. I suggest that the discrepancy between the climate modelling results which indicate seasonal temperature extremes, and the increasing body of geological information documenting a temperate climate, may be explained by the fact that the palaeogeography used in the models does not take into account the existence of these lakes and rivers, which would have had a major influence on the regional climate. The results demonstrate the importance of incorporating accurate palaeogeographies into numerical modelling studies when attempting to reconstruct past climates.
C1 SWISS FED INST TECHNOL,INST GEOL,CH-8092 ZURICH,SWITZERLAND.
C3 Swiss Federal Institutes of Technology Domain; ETH Zurich
NR 50
TC 41
Z9 43
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 51
EP 54
DI 10.1038/361051a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800043
DA 2026-03-10
ER

PT J
AU WHITE, SDM
   NAVARRO, JF
   EVRARD, AE
   FRENK, CS
AF WHITE, SDM
   NAVARRO, JF
   EVRARD, AE
   FRENK, CS
TI THE BARYON CONTENT OF GALAXY CLUSTERS - A CHALLENGE TO COSMOLOGICAL ORTHODOXY
SO NATURE
LA English
DT Article
ID coma cluster; dark matter; iras galaxy; x-ray; redshift survey; rich clusters; evolution; mass; universe; field
AB Baryonic matter constitutes a larger fraction of the total mass of rich galaxy clusters than is predicted by a combination of cosmic nucleosynthesis considerations (light-element formation during the Big Bang) and standard inflationary cosmology. This cannot be accounted for by gravitational and dissipative effects during cluster formation. Either the density of the Universe is less than that required for closure, or there is an error in the standard interpretation of element abundances.
C1 UNIV DURHAM,DEPT PHYS,DURHAM DH1 3LE,ENGLAND.
   UNIV MICHIGAN,DEPT PHYS,ANN ARBOR,MI 48109.
C3 Durham University; University of Michigan System; University of Michigan
RP WHITE, SDM (corresponding author), UNIV CAMBRIDGE,INST ASTRON,MADINGLEY RD,CAMBRIDGE CB3 0HA,ENGLAND.
NR 47
TC 881
Z9 932
U1 1
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 429
EP 433
DI 10.1038/366429a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800053
DA 2026-03-10
ER

PT J
AU VOS, MH
   RAPPAPORT, F
   LAMBRY, JC
   BRETON, J
   MARTIN, JL
AF VOS, MH
   RAPPAPORT, F
   LAMBRY, JC
   BRETON, J
   MARTIN, JL
TI VISUALIZATION OF COHERENT NUCLEAR MOTION IN A MEMBRANE-PROTEIN BY FEMTOSECOND SPECTROSCOPY
SO NATURE
LA English
DT Article
ID photosynthetic reaction centers; inelastic neutron-scattering; pancreatic trypsin-inhibitor; bacterial reaction centers; electron-transfer; rhodobacter-capsulatus; globular protein; primary donor; real-time; dynamics
AB Multicolour near-infrared femtosecond experiments of a genetically modified bacterial reaction centre show that the phase of two excited-state vibrational modes is conserved for a period of picoseconds over a large range of temperatures. The direct visualization of low-frequency nuclear vibrations in this protein, which is embedded in its natural membrane, implicates coherent nuclear motion in the primary electron transfer reaction in functional reaction centres.
C1 ECOLE POLYTECH,ENSTA,INSERM,U275,OPT APPL LAB,F-91120 PALAISEAU,FRANCE.
   CENS,DEPT BIOL,SERV BIOPHYS,F-91191 GIF SUR YVETTE,FRANCE.
C3 Institut National de la Sante et de la Recherche Medicale (Inserm); Institut Polytechnique de Paris; ENSTA Paris; Ecole Polytechnique; CEA
NR 39
TC 527
Z9 560
U1 0
U2 80
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 320
EP 325
DI 10.1038/363320a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700043
DA 2026-03-10
ER

PT J
AU SHARP, D
   BLINDERMAN, L
   COMBS, KA
   KIENZLE, B
   RICCI, B
   WAGERSMITH, K
   GIL, CM
   TURCK, CW
   BOUMA, ME
   RADER, DJ
   AGGERBECK, LP
   GREGG, RE
   GORDON, DA
   WETTERAU, JR
AF SHARP, D
   BLINDERMAN, L
   COMBS, KA
   KIENZLE, B
   RICCI, B
   WAGERSMITH, K
   GIL, CM
   TURCK, CW
   BOUMA, ME
   RADER, DJ
   AGGERBECK, LP
   GREGG, RE
   GORDON, DA
   WETTERAU, JR
TI CLONING AND GENE DEFECTS IN MICROSOMAL TRIGLYCERIDE TRANSFER PROTEIN ASSOCIATED WITH ABETALIPOPROTEINEMIA
SO NATURE
LA English
DT Article
ID hep g2 cells; apolipoprotein-b; intracellular degradation; disulfide isomerase; secretion; lipoproteins; complex; sites
AB THE microsomal triglyceride transfer protein (MTP), which catalyses the transport of triglyceride, cholesteryl ester and phospholipid between phospholipid surfaces, is a heterodimer composed of the multifunctional protein, protein disulphide isomerase, and a unique large subunit with an apparent M(r) of 88K (refs 1-3).  It is isolated as a soluble protein from the lumen of the microsomal fraction of liver and intestine4. The large subunit of MTP was not detectable in four unrelated subjects with abetatipoproteinaemia5, a rare autosomal recessive disease characterized by a defect in the assembly or secretion of plasma lipoproteins that contain apolipoprotein B (ref. 6). We report here the isolation and sequencing of complementary DNA encoding the large subunit of MTP. A comparison of this sequence to corresponding genomic sequences from two abetatipoproteinaemic subjects revealed a homozygous frameshift mutation in one subject and a homozygous nonsense mutation in the other. The results indicate that a defect in the gene for die large subunit of MTP is the proximal cause of abetalipoproteinaemia in these two subjects, and that MTP is required for the secretion of plasma lipoproteins that contain apolipoprotein B.
C1 BRISTOL MYERS SQUIBB,DEPT METAB DIS,PRINCETON,NJ 08543.
   UNIV CINCINNATI,DEPT PHARMACOL & CELL BIOPHYS,CINCINNATI,OH 45267.
   UNIV CALIF SAN FRANCISCO,HOWARD HUGHES MED INST,DEPT MED,SAN FRANCISCO,CA 94143.
   UNIV PARIS 07,INSERM,U327,F-75018 PARIS,FRANCE.
   NHLBI,MOLEC DIS BRANCH,BETHESDA,MD 20892.
   CNRS,CTR GENET MOLEC,F-91198 GIF SUR YVETTE,FRANCE.
C3 Bristol-Myers Squibb; University System of Ohio; University of Cincinnati; University of California System; University of California San Francisco; Howard Hughes Medical Institute; Universite Paris Cite; Institut National de la Sante et de la Recherche Medicale (Inserm); National Institutes of Health (NIH) - USA; NIH National Heart Lung & Blood Institute (NHLBI); Universite Paris Saclay; Centre National de la Recherche Scientifique (CNRS)
NR 17
TC 373
Z9 402
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 65
EP 69
DI 10.1038/365065a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600055
PM 8361539
DA 2026-03-10
ER

PT J
AU ROSSEINSKY, MJ
   MURPHY, DW
   FLEMING, RM
   ZHOU, O
AF ROSSEINSKY, MJ
   MURPHY, DW
   FLEMING, RM
   ZHOU, O
TI INTERCALATION OF AMMONIA INTO K3C60
SO NATURE
LA English
DT Article
AB THE superconducting transition temperatures (T(c)s) in the alkali-metal-doped C60 superconductors (A3C60) seem to be determined by the size of the face-centred cubic (f.c.c.) unit cell, which in turn is dependent largely on the size of the metal cations occupying the interstitial sites1. We have shown previously2 that intercalation of ammonia into Na2CsC60 expands the unit cell and thereby increases T(c) by approximately 20 K. This has prompted us to explore the generality of this effect by attempting to expand the lattice of A3C60 superconductors containing larger cations. Here we show that intercalation of ammonia into K3C60 (which has a T(c) of approximately 19 K) yields (NH3)K3C60, which has a structure that can be described as an orthorhombic distortion of the f.c.c. structure with one K and one NH3 per octahedral site. Despite strong evidence that the extent of charge transfer from K to C60 is unchanged by ammonia intercalation, the compound is not superconducting. We believe that the absence of superconductivity is a consequence of electron localization resulting from the structural distortion. Thus the change in symmetry of the unit cell, as well as the cell size, may be an important factor in attempts to create C60-based superconductors with high T(c)s.
C1 AT&T BELL LABS,MURRAY HILL,NJ 07974.
C3 AT&T; Nokia Corporation; Nokia Bell Labs
RP ROSSEINSKY, MJ (corresponding author), UNIV OXFORD,INORGAN CHEM LAB,S PARKS RD,OXFORD OX1 3QR,ENGLAND.
NR 8
TC 109
Z9 111
U1 0
U2 18
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 425
EP 427
DI 10.1038/364425a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000048
DA 2026-03-10
ER

PT J
AU MEIEREWERT, S
   MAIER, E
   AHMADI, A
   CURTIS, J
   LEHRACH, H
AF MEIEREWERT, S
   MAIER, E
   AHMADI, A
   CURTIS, J
   LEHRACH, H
TI AN AUTOMATED APPROACH TO GENERATING EXPRESSED SEQUENCE CATALOGS
SO NATURE
LA English
DT Article
ID dna; hybridization
RP MEIEREWERT, S (corresponding author), IMPERIAL CANC RES FUND,GENOME ANAL LAB,44 LINCOLNS INN FIELDS,POB 123,LONDON WC2A 3PX,ENGLAND.
NR 14
TC 96
Z9 106
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 375
EP 376
DI 10.1038/361375a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000068
PM 8426656
DA 2026-03-10
ER

PT J
AU TOMKINSON, AE
   BARDWELL, AJ
   BARDWELL, L
   TAPPE, NJ
   FRIEDBERG, EC
AF TOMKINSON, AE
   BARDWELL, AJ
   BARDWELL, L
   TAPPE, NJ
   FRIEDBERG, EC
TI YEAST DNA-REPAIR AND RECOMBINATION PROTEINS RAD1 AND RAD10 CONSTITUTE A SINGLE-STRANDED-DNA ENDONUCLEASE
SO NATURE
LA English
DT Article
ID saccharomyces-cerevisiae; excision repair; molecular characterization; mitotic recombination; nucleotide-sequence; cdna cloning; gene; helicase; purification; homology
AB DAMAGE-SPECIFIC recognition and incision of DNA during nucleotide excision repair in yeast1 and mammalian cells2 requires multiple gene products. Amino-acid sequence homology between several yeast and mammalian genes suggests that the mechanism of nucleotide excision repair is conserved in eukaryotes2-7, but very little is known about its biochemistry. In the yeast Saccharomyces cerevisiae at least 6 genes are needed for this process, including RAD1 and RAD10 (ref. 1). Mutations in the two genes inactivate nucleotide excision repair8,9 and result in a reduced efficiency of mitotic recombinational events between repeated sequences10-15. The Rad10 protein has a stable and specific interaction with Rad1 protein16,17 and also binds to single-stranded DNA and promotes annealing of homologous single-stranded DNA18 The amino-acid sequence of the yeast Rad10 protein is homologous with that of the human excision repair gene ERCC1 (ref. 3). Here we demonstrate that a complex of purified Rad1 and Rad10 proteins specifically degrades single-stranded DNA by an endonucleolytic mechanism. This endonuclease activity is presumably required to remove non-homologous regions of single-stranded DNA during mitotic recombination between repeated sequences as previously suggested13, and may also be responsible for the specific incision of damaged DNA during nucleotide excision repair.
C1 UNIV TEXAS,SW MED CTR,DEPT PATHOL,MOLEC PATHOL LAB,DALLAS,TX 75235.
C3 University of Texas System; University of Texas Southwestern Medical Center; University of Texas Dallas
NR 29
TC 183
Z9 209
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 860
EP 862
DI 10.1038/362860a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300064
PM 8479526
DA 2026-03-10
ER

PT J
AU TURNER, S
   HAWKESWORTH, C
   LIU, JQ
   ROGERS, N
   KELLEY, S
   VANCALSTEREN, P
AF TURNER, S
   HAWKESWORTH, C
   LIU, JQ
   ROGERS, N
   KELLEY, S
   VANCALSTEREN, P
TI TIMING OF TIBETAN UPLIFT CONSTRAINED BY ANALYSIS OF VOLCANIC-ROCKS
SO NATURE
LA English
DT Article
AB THE Tibetan plateau has had a central role in the development of recent models for the mechanics of mountain belts1,2 and Cenozoic global climate change3. The present elevation and extensional deformation of the plateau probably result from uplift owing to convective thinning of the underlying lithospheric mantle1,2. An age for the uplift would provide a valuable constraint on these models; but because recently proposed indicators of uplift are all climate-dependent, they are equivocal, possibly reflecting global cooling rather than regional uplift4. Here we present new geochemical data on post-mid-Miocene lavas from the plateau, which show that the lavas were derived from the lithospheric mantle. Simple thermal arguments indicate that the generation of such magmas also necessitates thinning of the lithospheric mantle. Thus volcanism is coincident with uplift, providing a climate-independent means of dating the onset of uplift. Dating by the laser 40Ar/39Ar technique places the beginning of this volcanism, and therefore the time of uplift of the Tibetan plateau, at 13 Myr ago.
C1 CHINESE ACAD SCI, UK INST GEOL, BEIJING 100011, PEOPLES R CHINA.
C3 Chinese Academy of Sciences
RP TURNER, S (corresponding author), OPEN UNIV, DEPT EARTH SCI, MILTON KEYNES MK7 6AA, BUCKS, ENGLAND.
NR 2
TC 431
Z9 591
U1 2
U2 96
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 50
EP 54
DI 10.1038/364050a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800053
DA 2026-03-10
ER

PT J
AU CARTER, NS
   FAIRLAMB, AH
AF CARTER, NS
   FAIRLAMB, AH
TI ARSENICAL-RESISTANT TRYPANOSOMES LACK AN UNUSUAL ADENOSINE TRANSPORTER
SO NATURE
LA English
DT Article
ID african trypanosm; nucleoside transporters; leishmania-donovani; brucei; drugs; trypanothione; allopurinol; metabolism; purine; cells
AB THE melaminophenyl arsenical melarsoprol is still used to treat African sleeping sickness1-3, a disease caused by parasitic protozoa of the Trypanosoma brucei subgroup. Based on the observation that melamine antagonizes the trypanocidal activity of this class of drugs4, we investigated whether other physiological compounds could compete for the same receptor. Here we report that the in vitro trypanolytic effect of melarsen oxide can be specifically abrogated by adenine, adenosine and dipyridamole, all of which compete for uptake by an adenosine transporter. Melarsen-sensitive trypanosomes have two high-affinity adenosine transport systems: a P1 type, which also transports inosine; and a P2 type, which also transports adenine and the melaminophenyl arsenicals, Melarsen-resistant trypanosomes lack P2 adenosine transport, suggesting that resistance to these arsenicals is due to loss of uptake.
C1 UNIV LONDON LONDON SCH HYG & TROP MED, DEPT MED PARASITOL, KEPPEL ST, LONDON WC1E 7HT, ENGLAND.
C3 University of London; London School of Hygiene & Tropical Medicine
FU Wellcome Trust Funding Source: Medline
NR 34
TC 319
Z9 346
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 173
EP 176
DI 10.1038/361173a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600066
PM 8421523
DA 2026-03-10
ER

PT J
AU HUGHES, DA
   ASHWORTH, A
   MARSHALL, CJ
AF HUGHES, DA
   ASHWORTH, A
   MARSHALL, CJ
TI COMPLEMENTATION OF BYR1 IN FISSION YEAST BY MAMMALIAN MAP KINASE KINASE REQUIRES COEXPRESSION OF RAF KINASE
SO NATURE
LA English
DT Article
ID nerve growth-factor; protein-kinase; schizosaccharomyces-pombe; signal transduction; gene; activation; fus3; cerevisiae; tyrosine; kss1
AB INTRACELLULAR signalling from receptor tyrosine kinases in mammalian cells involves the activation of a signal cascade which includes p21ras and the protein kinases p74raf-1, MAP kinase kinase and MAP kinases1-8. In the yeasts Schizosaccharomyces pombe and Saccharomyces cerevisiae the response to mating pheromones requires the Spk1 and KSS1/FUS3 kinases, which have sequence homology to Vertebrate MAP kinases9-12. The recent cloning of complementary DNAs for mammalian13-15 and frog16 MAP kinase kinases has shown that they are homologous to the S. pombe Byr1 (ref. 17) and S. cerevisiae STE7 (ref. 18) kinases, which have been proposed to function upstream of Spk1 and KSS1/FUS3, respectively19-22. We have investigated whether these apparently similar kinase pathways are functionally conserved between vertebrates and S. pombe. We report here that expression of mammalian MAP kinase kinase alone fails to complement a byr1 mutant of S. pombe. When coexpressed with Raf kinase, however, MAP kinase kinase is activated by phosphorylation and the mating defect of the byr1 mutant is rescued. This suggests that the pathways are functionally homologous and that Raf kinase may directly phosphorylate and activate MAP kinase kinase.
RP HUGHES, DA (corresponding author), INST CANC RES, CHESTER BEATTY LABS, CELL & MOLEC BIOL SECT, LONDON SW3 6JB, ENGLAND.
NR 35
TC 64
Z9 84
U1 0
U2 3
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 349
EP 352
DI 10.1038/364349a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000061
PM 8332194
DA 2026-03-10
ER

PT J
AU BLANKENSHIP, DD
   BELL, RE
   HODGE, SM
   BROZENA, JM
   BEHRENDT, JC
   FINN, CA
AF BLANKENSHIP, DD
   BELL, RE
   HODGE, SM
   BROZENA, JM
   BEHRENDT, JC
   FINN, CA
TI ACTIVE VOLCANISM BENEATH THE WEST ANTARCTIC ICE-SHEET AND IMPLICATIONS FOR ICE-SHEET STABILITY
SO NATURE
LA English
DT Article
ID stream
AB IT is widely understood that the collapse of the West Antarctic ice sheet (WAIS) would cause a global sea level rise of 6 m, yet there continues to be considerable debate about the detailed response of this ice sheet to climate change1-3. Because its bed is grounded well below sea level, the stability of the WAIS may depend on geologically controlled conditions at the base which are independent of climate. In particular, heat supplied to the base of the ice sheet could increase basal melting and thereby trigger ice streaming, by providing the water for a lubricating basal layer of till on which ice streams are thought to slide4,5. Ice streams act to protect the reservoir of slowly moving inland ice from exposure to oceanic degradation, thus enhancing ice-sheet stability. Here we present aerogeophysical evidence for active volcanism and associated elevated heat flow beneath the WAIS near the critical region where ice streaming begins. If this heat flow is indeed controlling ice-stream formation, then penetration of ocean waters inland of the thin hot crust of the active portion of the West Antarctic rift system could lead to the disappearance of ice streams, and possibly trigger a collapse of the inland ice reservoir.
C1 COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964.
   US GEOL SURVEY,TACOMA,WA 98406.
   US GEOL SURVEY,DENVER,CO 80225.
   USN,RES LAB,WASHINGTON,DC 20375.
C3 Columbia University; United States Department of the Interior; United States Geological Survey; United States Department of the Interior; United States Geological Survey; United States Department of Defense; United States Navy; United States Naval Research Laboratory; NRL Chesapeake
RP BLANKENSHIP, DD (corresponding author), UNIV TEXAS,INST GEOPHYS,AUSTIN,TX 78759, USA.
NR 17
TC 160
Z9 178
U1 1
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 526
EP 529
DI 10.1038/361526a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400056
DA 2026-03-10
ER

PT J
AU SCHULTZ, JR
   VERSTUYFT, JG
   GONG, EL
   NICHOLS, AV
   RUBIN, EM
AF SCHULTZ, JR
   VERSTUYFT, JG
   GONG, EL
   NICHOLS, AV
   RUBIN, EM
TI PROTEIN-COMPOSITION DETERMINES THE ANTI-ATHEROGENIC PROPERTIES OF HDL IN TRANSGENIC MICE
SO NATURE
LA English
DT Article
ID high-density-lipoprotein; apolipoprotein-a-i; coronary-artery disease; cholesterol efflux; particles; atherosclerosis; size; susceptibility; expression; cells
AB HIGH-DENSITY lipoprotein (HDL) contains two major proteins, apolipoprotein A-I (apoA-I) and apolipoprotein A-II (apoA-II), comprising about 70% and 20% of the total HDL protein mass, respectively. HDL exists in human plasma in two main forms, one containing apoA-I with apoA-II (AI/AII-HDL) and another containing apoA-I without apoA-II (AI-HDL). A strong inverse relationship exists between total plasma HDL concentration and atherosclerosis, but the results of studies examining the relationship between AI-HDL and AI/AII-HDL and atherosclerosis have been conflicting1-9. To determine whether these two HDL populations have different effects on atherogenesis, human apoA-I (AI) and human apoA-I and apoA-II (AI/AII) transgenic mice were produced in an atherosclerosis-susceptible strain10-12. Following an atherogenic diet, despite similar total cholesterol and HDL cholesterol concentrations, the area of atherogenic lesions in the AI/AII mice was 15-fold greater than in the AI animals. These studies show that the protein composition of HDL significantly affects its role in atherogenesis and that AI-HDL is more anti-atherogenic than AI/AII-HDL.
C1 LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720.
C3 United States Department of Energy (DOE); Lawrence Berkeley National Laboratory
NR 30
TC 260
Z9 278
U1 1
U2 16
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 762
EP 764
DI 10.1038/365762a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200066
PM 8413656
DA 2026-03-10
ER

PT J
AU WYNICK, D
   HAMMOND, PJ
   AKINSANYA, KO
   BLOOM, SR
AF WYNICK, D
   HAMMOND, PJ
   AKINSANYA, KO
   BLOOM, SR
TI GALANIN REGULATES BASAL AND ESTROGEN-STIMULATED LACTOTROPH FUNCTION
SO NATURE
LA English
DT Article
ID vasoactive-intestinal-peptide; rat pituitary-cells; thyrotropin-releasing-hormone; anterior-pituitary; prolactin secretion; possible involvement; estrogen; immunoreactivity; polypeptide; tumor
AB OESTROGEN, an essential physiological regulator of reproductive function1, controls lactotroph proliferation and prolactin release2. The neuropeptide galanin co-localizes to the lactotroph3, but its physiological function is largely unknown. Pituitary galanin expression is extremely sensitive to the oestrogen status of the animal. A marked elevation occurs during pregnancy and lactation 4, and exogenous 17beta-oestradiol can cause a 4,000-fold increase in messenger RNA levels5. Here we report that galanin is secreted by a minority of lactotrophs and is essential for the regulation of basal and vasoactive-intestinal-polypeptide-stimulated prolactin release. Hyperoestrogenization increases the number of galanin-secreting cells and the resulting increase in basal prolactin release is completely abolished by treatment with galanin antiserum. Galanin is a potent lactotroph growth factor and galanin-immunoneutralization completely inhibits the previously reported6-8 mitogenic effects of oestrogen on the lactotroph. These findings represent direct evidence for paracrine regulation of lactotroph function and demonstrate that the effect of oestrogen on lactotroph proliferation and prolactin release are mediated by locally secreted galanin.
C1 HAMMERSMITH HOSP, DEPT MED, DUCANE RD, LONDON W12 0NN, ENGLAND.
C3 Imperial College London
NR 29
TC 123
Z9 124
U1 0
U2 1
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 529
EP 532
DI 10.1038/364529a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700055
PM 7687748
DA 2026-03-10
ER

PT J
AU VARTANYAN, SL
   GARUTT, VE
   SHER, AV
AF VARTANYAN, SL
   GARUTT, VE
   SHER, AV
TI HOLOCENE DWARF MAMMOTHS FROM WRANGEL-ISLAND IN THE SIBERIAN ARCTIC
SO NATURE
LA English
DT Article
AB THE cause of extinction of the woolly mammoth, Mammuthus primigenius (Blumenbach), is still debated. A major environmental change at the Pleistocene-Holocene boundary, hunting by early man, or both together are among the main explanations that have been suggested. But hardly anyone has doubted that mammoths had become extinct everywhere by around 9,500 years before present (BP). We report here new discoveries on Wrangel Island in the Arctic Ocean that force this view to be revised. Along with normal-sized mammoth fossils dating to the end of the Pleistocene, numerous teeth of dwarf mammoth dated 7,000-4,000 yr BP have been found there. The island is thought to have become separated from the mainland by 12,000 yr BP. Survival of a mammoth population may be explained by local topography and climatic features, which permitted relictual preservation of communities of steppe plants. We interpret the dwarfing of the Wrangel mammoths as a result of the insularity effect, combined with a response to the general trend towards unfavourable environment in the Holocene.
C1 AN SEVERTSOV EVOLUTIONARY ANIM MORPHOL & ECOL INST,33 LENINSKIY PROSPECT,MOSCOW 117071,RUSSIA.
   WRANGEL ISL STATE RESERVE,USHAKOVSKOYE 686870,RUSSIA.
   RUSSIAN ACAD SCI,INST ZOOL,ST PETERSBURG 199034,RUSSIA.
C3 Russian Academy of Sciences; Saratov Scientific Center of the Russian Academy of Sciences; Severtsov Institute of Ecology & Evolution; Russian Academy of Sciences; Zoological Institute of the Russian Academy of Sciences
NR 31
TC 188
Z9 208
U1 0
U2 83
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 337
EP 340
DI 10.1038/362337a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600058
PM 29633990
DA 2026-03-10
ER

PT J
AU CLARKE, AR
   PURDIE, CA
   HARRISON, DJ
   MORRIS, RG
   BIRD, CC
   HOOPER, ML
   WYLLIE, AH
AF CLARKE, AR
   PURDIE, CA
   HARRISON, DJ
   MORRIS, RG
   BIRD, CC
   HOOPER, ML
   WYLLIE, AH
TI THYMOCYTE APOPTOSIS INDUCED BY P53-DEPENDENT AND INDEPENDENT PATHWAYS
SO NATURE
LA English
DT Article
ID dna fragmentation; gene; cells; p53; expression; induction; death
AB DEATH by apoptosis is characteristic of cells undergoing deletion during embryonic development, T- and B-cell maturation and endocrine-induced atrophy1. Apoptosis can be initiated by various agents1-5 and may be a result of expression of the oncosuppressor gene p53 (refs 6-8). Here we study the dependence of apoptosis on p53 expression in cells from the thymus cortex. Short-term thymocyte cultures were prepared from mice constitutively heterozygous or homozygous for a deletion in the p53 gene introduced into the germ line after gene targeting. Wild-type thymocytes readily undergo apoptosis after treatment with ionizing radiation, the glucocorticoid methylprednisolone, or etoposide (an inhibitor of topoisomerase II), or after Ca2+-dependent activation by phorbol ester and a calcium ionophore. In contrast, homozygous null p53 thymocytes are resistant to induction of apoptosis by radiation or etoposide, but retain normal sensitivity to glucocorticoid and calcium. The time-dependent apoptosis that occurs in untreated cultures is unaffected by p53 status. Cells heterozygous for p53 deletion are partially resistant to radiation and etoposide. Our results show that p53 exerts a significant and dose-dependent effect in the initiation of apoptosis, but only when it is induced by agents that cause DNA-strand breakage.
RP CLARKE, AR (corresponding author), UNIV EDINBURGH, SCH MED, DEPT PATHOL, CANC RES CAMPAIGN LABS, TEVIOT PL, EDINBURGH EH8 9AG, MIDLOTHIAN, SCOTLAND.
NR 26
TC 2440
Z9 2588
U1 0
U2 68
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 849
EP 852
DI 10.1038/362849a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300060
PM 8479523
DA 2026-03-10
ER

PT J
AU TANAKA, Y
   ADAMS, DH
   HUBSCHER, S
   HIRANO, H
   SIEBENLIST, U
   SHAW, S
AF TANAKA, Y
   ADAMS, DH
   HUBSCHER, S
   HIRANO, H
   SIEBENLIST, U
   SHAW, S
TI T-CELL ADHESION INDUCED BY PROTEOGLYCAN-IMMOBILIZED CYTOKINE MIP-1-BETA
SO NATURE
LA English
DT Article
ID lymphocytes-t; cd44; protein; activation; receptor; family; glycosaminoglycans; hyaluronate; molecule-1; adherence
AB LYMPHOCYTE migration from blood into tissue depends on integrin-mediated adhesion to endothelium1-4. Adhesion requires not only integrin ligands on the endothelium, but also activation signals because T-cell integrins cannot bind well until they are activated. The physiological 'triggers' for T-cell adhesion are unknown, but cytokines may be good candidates as they are released during inflammation and trigger adhesion in neutrophils and monocytes2,5,6. We have identified a cytokine, macrophage inflammatory protein-1beta (MIP-1beta),that induces both chemotaxis and adhesion of T cells; MIP-1beta is most effective at augmenting adhesion of CD8+ T cells to the vascular cell adhesion molecule VCAM-1. We reasoned that, as cytokines in vivo will be rapidly washed away, MIP-1beta might be bound to endothelial surfaces and so induce adhesion in its immobilized form. Here we show that: (1) MIP-1beta is present on lymph node endothelium; (2) immobilized MIP-1beta induces binding of T cells to VCAM-1 in vitro. MIP-1beta was immobilized by binding to proteoglycan: a conjugate of heparin with bovine serum albumin and cellular proteoglycan CD44 were both effective. We propose that MIP-1beta and other cytokines with glycosaminoglycan-binding sites will bind to and be presented by endothelial proteoglycans to trigger adhesion selectively not only of lymphocyte subsets, but also of other cell types.
C1 UNIV BIRMINGHAM,DEPT PATHOL,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND.
   NIAID,IMMUNOREGULAT LAB,BETHESDA,MD 20892.
C3 University of Birmingham; National Institutes of Health (NIH) - USA; NIH National Institute of Allergy & Infectious Diseases (NIAID)
RP TANAKA, Y (corresponding author), NCI,EXPTL IMMUNOL BRANCH,BETHESDA,MD 20892, USA.
NR 40
TC 812
Z9 854
U1 0
U2 19
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 79
EP 82
DI 10.1038/361079a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800053
PM 7678446
DA 2026-03-10
ER

PT J
AU OLINER, JD
   PIETENPOL, JA
   THIAGALINGAM, S
   GVURIS, J
   KINZLER, KW
   VOGELSTEIN, B
AF OLINER, JD
   PIETENPOL, JA
   THIAGALINGAM, S
   GVURIS, J
   KINZLER, KW
   VOGELSTEIN, B
TI ONCOPROTEIN MDM2 CONCEALS THE ACTIVATION DOMAIN OF TUMOR SUPPRESSOR-P53
SO NATURE
LA English
DT Article
ID p53 protein; wild-type; sequences; gene
AB THE tumour-suppressor gene p53 is inactivated in most human malignancies1 either by missense mutations1 or by binding to oncogenic proteins2-4. In human soft tissue sarcomas, inactivation apparently results from MDM2 gene amplification4. MDM2 is an oncogene product5,6 that may function by binding to p53 and inhibiting its ability to activate transcription3 . Here we show that, when expressed in Saccharomyces cerevisiae, human MDM2 inhibits human p53's ability to stimulate transcription by binding to a region that nearly coincides with the p53 acidic activation domain. The isolated p53 activation domain fused to another DNA-binding protein is also inactivated by MDM2, confirming that MDM2 can inhibit p53 function by concealing the activation domain of p53 from the cellular transcription machinery.
C1 JOHNS HOPKINS ONCOL CTR,424 N BOND ST,BALTIMORE,MD 21231.
   JOHNS HOPKINS UNIV,SCH MED,PROGRAM HUMAN GENET,BALTIMORE,MD 21205.
   HARVARD UNIV,SCH MED,DEPT GENET,BOSTON,MA 02115.
   MASSACHUSETTS GEN HOSP,DEPT MOLEC BIOL,BOSTON,MA 02114.
C3 Johns Hopkins University; Johns Hopkins Medicine; Johns Hopkins University; Harvard University; Harvard Medical School; Harvard University; Harvard University Medical Affiliates; Massachusetts General Hospital
NR 27
TC 1383
Z9 1598
U1 1
U2 57
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 857
EP 860
DI 10.1038/362857a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300063
PM 8479525
DA 2026-03-10
ER

PT J
AU SCOTTI, JV
   MELOSH, HJ
AF SCOTTI, JV
   MELOSH, HJ
TI ESTIMATE OF THE SIZE OF COMET SHOEMAKER-LEVY-9 FROM A TIDAL BREAKUP MODEL
SO NATURE
LA English
DT Article
AB THE spectacular 'string-of-pearls' appearance of periodic comet Shoemaker-Levy 9 (1993e) and its impending encounter with Jupiter's atmosphere have caused a flurry of speculation on the likely effects of the impact1. The magnitudes of the predicted effects depend critically on the masses of the fragments composing the chain, although these are currently poorly constrained. However, some limits on the comet's total size, and hence mass, can be obtained by considering its dynamical history. On its previous swing past Jupiter, the comet apparently passed within the Roche limit of the planet2,3, and it therefore seems likely that the present chain of about twenty nuclei was created when a single progenitor was split by tidal forces during closest approach. Here we describe a simple model of tidal splitting which is able to reproduce closely both the length of the observed chain and its position angle on the sky as a function of time. The length of the fragment chain is directly proportional to the size of the parent object, which we estimate to have been only about 2 km in diameter.
RP SCOTTI, JV (corresponding author), UNIV ARIZONA,LUNAR & PLANETARY LAB,TUCSON,AZ 85721, USA.
NR 7
TC 86
Z9 91
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 733
EP 735
DI 10.1038/365733a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200055
DA 2026-03-10
ER

PT J
AU VANDERPUTTEN, WH
   VANDIJK, C
   PETERS, BAM
AF VANDERPUTTEN, WH
   VANDIJK, C
   PETERS, BAM
TI PLANT-SPECIFIC SOIL-BORNE DISEASES CONTRIBUTE TO SUCCESSION IN FOREDUNE VEGETATION
SO NATURE
LA English
DT Article
ID hippophae-rhamnoides l; ammophila-arenaria; growth; organisms; degeneration; nodulation; dune
AB ECOLOGICAL study of the role of soil microorganisms in vegetation succession has focused mainly on organisms affecting plant nutrition, such as mycorrhiza and nitrogen-fixing bacteria. But, soil-borne diseases are involved in the degeneration of Ammophila arenaria (Marram grass) and Hippophae rhamnoides (Sea buck-thorn), two plant species that dominate the coastal foredunes of Europe and are widely planted for sand stabilization. We have used reciprocal transplantation and report here that soil-borne diseases may contribute to the succession of foredune plant species. In pot experiments, plant species that succeed A. arenaria were tolerant of the soil-borne diseases of this species. Plant species that were grown in soils from both previous and later succession stages were reduced most in soils from the later stages. During foredune succession, therefore, plants disappear from sites where the soil has become colonized with specific growth-depressing microorganisms. The soil-borne diseases must have considerable importance for the outcome of interspecific competition and may be involved in patterns of clonal growth. The different sensitivities of plant species for the soil-borne pathogens could be an evolutionary response to selection pressures of the succession stage to which a species is confined by the combined effect of local abiotic and biotic environmental factors.
RP VANDERPUTTEN, WH (corresponding author), NETHERLANDS INST ECOL,CTR TERR ECOL,POB 40,6666 ZG HETEREN,NETHERLANDS.
NR 31
TC 506
Z9 585
U1 2
U2 249
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 53
EP 56
DI 
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600057
DA 2026-03-10
ER

PT J
AU SCHMIDT, BP
   KIRSHNER, RP
   EASTMAN, RG
   GRASHUIS, R
   DELLANTONIO, I
   CALDWELL, N
   FOLTZ, C
   HUCHRA, JP
   MILONE, AAE
AF SCHMIDT, BP
   KIRSHNER, RP
   EASTMAN, RG
   GRASHUIS, R
   DELLANTONIO, I
   CALDWELL, N
   FOLTZ, C
   HUCHRA, JP
   MILONE, AAE
TI THE UNUSUAL SUPERNOVA SN1993J IN THE GALAXY M81
SO NATURE
LA English
DT Article
ID extragalactic distance scale; sn-1987a
AB SUPERNOVA 1993J in the galaxy M81 is the second-brightest type II supernova observed this century, surpassed only by SN1987A in the Large Magellanic Cloud. Here we report the evolution of the photometric and spectral properties of SN1993J for the first 50 days following its discovery. The behaviour of this supernova is unusual, showing features typical of type II supernovae near the initial maximum, but with the strong helium lines characteristic of type Ib supernovae at later times. This implies that the progenitor star had an unusually thin hydrogen envelope (compared to normal type II progenitors), suggesting that significant mass loss had taken place before the explosion. Application of an expanding photosphere model1 to our data provides an estimate of the distance to the supernova of 2.6+/-0.4 Mpc, broadly consistent with the distance to M81 determined using Cepheid variable stars2. Supernova models that more closely match the atypical spectral features of SN1993J may change the inferred distance, and should provide better constraints on the structure of the progenitor.
C1 UNIV CALIF SANTA CRUZ,LICK OBSERV,BOARD STUDIES ASTRON & ASTROPHYS,SANTA CRUZ,CA 95064.
   UNIV NEW MEXICO,INST ASTRON,ALBUQUERQUE,NM 87131.
   UNIV ARIZONA,STEWARD OBSERV,MMT OBSERV,TUCSON,AZ 85721.
C3 University of California System; University of California Santa Cruz; University of New Mexico; University of Arizona
RP SCHMIDT, BP (corresponding author), HARVARD SMITHSONIAN CTR ASTROPHYS,60 GARDEN ST,CAMBRIDGE,MA 02138, USA.
NR 24
TC 79
Z9 85
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 600
EP 602
DI 10.1038/364600a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100043
DA 2026-03-10
ER

PT J
AU OSENSAND, A
   CATSICAS, M
   STAPLE, JK
   JONES, KA
   AYALA, G
   KNOWLES, J
   GRENNINGLOH, G
   CATSICAS, S
AF OSENSAND, A
   CATSICAS, M
   STAPLE, JK
   JONES, KA
   AYALA, G
   KNOWLES, J
   GRENNINGLOH, G
   CATSICAS, S
TI INHIBITION OF AXONAL GROWTH BY SNAP-25 ANTISENSE OLIGONUCLEOTIDES IN-VITRO AND IN-VIVO
SO NATURE
LA English
DT Article
ID synaptosomal-associated protein; rat-brain; expression; terminals; retina; cells
AB AXONAL elongation and the transformation of growth cones to synaptic terminals are major steps of brain development and the molecular mechanisms involved form the basis of the correct wiring of the nervous system. The same mechanisms may also contribute to the remodelling of nerve terminals that occurs in the adult brain, as a morphological substrate to memory and learning1. We have investigated the function of the nerve terminal protein SNAP-25 (ref. 2) during development. We report here that SNAP-25 is expressed in axonal growth cones during late stages of elongation and that selective inhibition of SNAP-25 expression prevents neurite elongation by rat cortical neurons and PC-12 cells in vitro and by amacrine cells of the developing chick retina in vivo. These results demonstrate that SNAP-25 plays a key role in axonal growth. They also suggest that high levels of SNAP-25 expression in specific areas of the adult brain2 may contribute to nerve terminal plasticity.
C1 GLAXO INST MOLEC BIOL SA,14 CHEMIN AULX,CASE POSTALE 674,CH-1228 PLAN LES OUATES,SWITZERLAND.
   INST ANAT,CH-1005 LAUSANNE,SWITZERLAND.
C3 GlaxoSmithKline; GlaxoSmithKline Switzerland
NR 23
TC 371
Z9 410
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 445
EP 448
DI 10.1038/364445a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000055
PM 8332215
DA 2026-03-10
ER

PT J
AU JOHNSON, CM
   BEARD, BL
AF JOHNSON, CM
   BEARD, BL
TI EVIDENCE FROM HAFNIUM ISOTOPES FOR ANCIENT SUB-OCEANIC MANTLE BENEATH THE RIO-GRANDE RIFT
SO NATURE
LA English
DT Article
ID new-mexico; volcanic field; element abundances; earths mantle; rare-earth; evolution; basalts; rocks; sr; nd
AB UNDERSTANDING the nature of the mantle underlying continents is important for balancing the inventory of the Earth's main chemical reservoirs1,2 and for constraining aspects of mantle convection, such as the extent to which continental lithosphere is coupled to the asthenosphere beneath3-5. Strontium, neodymium and lead isotope studies of basaltic lavas from regions of continental extension, such as the southwestern United States, have identified at least two components of the sub-continental mantle6:  one composed of ancient lithosphere, enriched by the addition of metasomatic fluids or crustal material, and an asthenospheric component with Sr, Nd and Pb isotope compositions matching those of ocean-island basalts. The lutetium-hafnium isotope system7-9 provides additional information not obtainable from the other systems; in particular, by betraying the presence of garnet during melting10,11 (hence constraining the depth of previous melting events of the source mantle). Here we report that basalts derived from upwelling asthenosphere in the region of the Rio Grande rift, southwestern United States, have Nd and Hf isotope ratios that lie significantly off the ocean-island Nd-Hf array10. We interpret the low Hf-176/Hf-177 ratios in these basalts as reflecting derivation from ancient asthenospheric mantle that melted at shallow levels beneath the oceans. Hafnium isotopes in continental basalts may thus provide evidence for large-scale overriding by continents of sub-oceanic mantle.
C1 UNIV N CAROLINA,DEPT GEOL,CHAPEL HILL,NC 27599.
C3 University of North Carolina; University of North Carolina Chapel Hill
RP JOHNSON, CM (corresponding author), UNIV WISCONSIN,DEPT GEOL & GEOPHYS,MADISON,WI 53706, USA.
NR 41
TC 75
Z9 77
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 441
EP 444
DI 10.1038/362441a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400080
DA 2026-03-10
ER

PT J
AU RENBERG, I
   KORSMAN, T
   BIRKS, HJB
AF RENBERG, I
   KORSMAN, T
   BIRKS, HJB
TI PREHISTORIC INCREASES IN THE PH OF ACID-SENSITIVE SWEDISH LAKES CAUSED BY LAND-USE CHANGES
SO NATURE
LA English
DT Article
ID acidification; perspective; rain
AB IN the past few decades, there has been considerable debate about whether vegetational and soil changes associated with changing land-use can cause surface-water acidification in lakes1,2. Although it is now widely accepted that the severe and extensive acidification that has occurred recently in southern Scandinavia, northern Britain and North America3,4 has been chiefly caused by atmospheric acid deposition, the role of changing land-use for moderate acidification is still not fully understood5,6. Here we report analyses of sediment records from Swedish lakes, which provide evidence that land-use changes can have an important influence on the pH of acid-sensitive lakes. Following the expansion of an agrarian economy during the Iron Age (from about 2,500 years ago), pH increased from about 5.5 to about 6.5. Our results suggest that this pH increase was caused by burning, agriculture, forest grazing and other culture-related practices that increased the base saturation and pH of the soils, and enhanced the transport of base cations and nutrients from the soils to the surface waters, thus indicating these lakes may be naturally more acidic than had been thought. Following this period of alkalization, pH in many lakes fell to about 4.5 during the present century. Although cessation of former land-use practices could account for some of this change, the unprecedentedly low pH in recent years must be due predominantly to acid deposition.
C1 UNIV BERGEN,INST BOT,N-5007 BERGEN,NORWAY.
C3 University of Bergen
RP RENBERG, I (corresponding author), UMEA UNIV,DEPT ECOL BOT,S-90187 UMEA,SWEDEN.
NR 24
TC 100
Z9 106
U1 0
U2 43
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 824
EP 827
DI 10.1038/362824a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300050
DA 2026-03-10
ER

PT J
AU FFRENCHCONSTANT, RH
   ROCHELEAU, TA
   STEICHEN, JC
   CHALMERS, AE
AF FFRENCHCONSTANT, RH
   ROCHELEAU, TA
   STEICHEN, JC
   CHALMERS, AE
TI A POINT MUTATION IN A DROSOPHILA GABA RECEPTOR CONFERS INSECTICIDE RESISTANCE
SO NATURE
LA English
DT Article
ID gamma-aminobutyric-acid; alpha-subunit; picrotoxinin; sequence; channels; dieldrin; cloning; region; form; cdna
AB VERTEBRATES and invertebrates both have GABA (gamma-aminobutyric acid) as a major inhibitory neurotransmitter1,2. GABA(A) receptors in vertebrates assemble as heteromultimers to form an integral chloride ion channel3. These receptors are targets for drugs and pesticides4 and are also implicated in seizure-related diseases5,6. Picrotoxinin (PTX) and cyclodiene insecticides are GABA(A) receptor antagonists which competitively displace each other from the same binding site7. Insects8 and vertebrates9 showing resistance to cyclodienes also show cross-resistance to PTX. Previously, we used a field-isolated Drosophila mutant Rdl (Resistant to dieldrin)10 insensitive to PTX and cyclodienes to clone a putative GABA receptor11. Here we report the functional expression and novel pharmacology of this GABA receptor and examine the functionality of a resistance-associated point mutation (alanine to serine) within the second membrane-spanning domain, the region thought to line the chloride ion channel pore. This substitution is found globally in Drosophila populations12. This mutation not only identifies a single amino acid conferring high levels of resistance to the important GABA receptor antagonist PTX but also, by conferring resistance to cyclodienes, may account for over 60% of reported cases of insecticide resistance13.
C1 RHONE POULENC AG CO,RES TRIANGLE PK,NC 27709.
RP FFRENCHCONSTANT, RH (corresponding author), UNIV WISCONSIN,DEPT ENTOMOL,RUSSELL LABS 237,1630 LINDEN DR,MADISON,WI 53706, USA.
NR 32
TC 502
Z9 566
U1 2
U2 85
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 449
EP 451
DI 10.1038/363449a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800058
PM 8389005
DA 2026-03-10
ER

PT J
AU DAVENPORT, RW
   DOU, P
   REHDER, V
   KATER, SB
AF DAVENPORT, RW
   DOU, P
   REHDER, V
   KATER, SB
TI A SENSORY ROLE FOR NEURONAL GROWTH CONE FILOPODIA
SO NATURE
LA English
DT Article
ID calcium; generation; contacts; axons; degeneration; morphology; serotonin; targets; pathway; culture
AB THE dynamic nature of neuronal growth cone filopodia led to the suggestion that the primary function of filopodia is to sample their immediate environment1-3, responding to and transducing environmental signals that affect growth cone behaviour4-6 and shape7-11. Filopodia seem well suited to serve as antenna-like sensors, their broad span allows sampling of information over a greatly enhanced radius, and forward-projecting filopodia encounter potential cues in the molecular terrain long before the advancing growth cone itself12. Filopodia in culture can serve structural roles13, exert mechanical tension14-16 and selectively adhere to their surrounding17-20. Whether or not filopodia have a general sensory role has not been tested directly, largely because of their small size, which limits an electrophysiological approach, and their integral relationship with the parent growth cone, which prevents resolution of their different functions. Here we use surgical procedures to isolate individual filopodia from their parent growth cone and, by monitoring their morphology and calcium second messenger systems, we show that neuronal growth cone filopodia contain signal transduction mechanisms that allow autonomous responses and the transmission of distant environmental information to their parent growth cone.
C1 COLORADO STATE UNIV,DEPT ANAT & NEUROBIOL,PROGRAM NEURONAL GROWTH & DEV,FT COLLINS,CO 80523.
C3 Colorado State University System; Colorado State University Fort Collins
NR 34
TC 189
Z9 225
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 721
EP 724
DI 10.1038/361721a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900055
PM 8441465
DA 2026-03-10
ER

PT J
AU TRAUTWEIN, C
   CAELLES, C
   VANDERGEER, P
   HUNTER, T
   KARIN, M
   CHOJKIER, M
AF TRAUTWEIN, C
   CAELLES, C
   VANDERGEER, P
   HUNTER, T
   KARIN, M
   CHOJKIER, M
TI TRANSACTIVATION BY NF-IL6 LAP IS ENHANCED BY PHOSPHORYLATION OF ITS ACTIVATION DOMAIN
SO NATURE
LA English
DT Article
ID hepatocyte-stimulating factor; necrosis factor-alpha; acute phase response; protein-kinase; c-jun; nuclear-protein; phorbol esters; c/ebp; cells; gene
AB ONE of the members of the bZIP family of transcriptional activators1-5 is NF-IL6/LAP (IL-6 DBP, C/EBPbeta, CRP2). NF-IL6/LAP protein is highly expressed in liver nuclei2, where it has been implicated as a master regulator of the acute-phase response1,3,6,7, induced by interleukin-6 (IL-6) and other inflammatory mediators3,8. Also, NF-IL6/LAP is involved in the activation of the IL-6 promoter in response to IL-1 and bacterial lipopolysaccharide1,6. The control of NF-IL6/LAP expression and activity is complex and poorly understood. Under some conditions the NF-IL6/LAP gene is transcriptionally activated by IL-1 and lipopolysaccharide1, whereas in other instances, its binding to cognate DNA sequences is enhanced by cytokines1,3. Additionally, the ability of constitutively expressed NF-IL6/LAP to activate transcription is strongly augmented by IL-6, through an unknown signalling pathway. We now show that stimulation of the protein kinase C pathway increases the phosphorylation of Ser 105 within the activation domain of NF-IL6/LAP, and enhances its transcriptional efficacy.
C1 UNIV CALIF SAN DIEGO, DEPT PHARMACOL, LA JOLLA, CA 92093 USA.
   UNIV CALIF SAN DIEGO, DEPT MED, LA JOLLA, CA 92093 USA.
   UNIV CALIF SAN DIEGO, CTR MOLEC GENET, LA JOLLA, CA 92093 USA.
   VET AFFAIRS MED CTR, LA JOLLA, CA 92093 USA.
   SALK INST BIOL STUDIES, LA JOLLA, CA 92186 USA.
C3 University of California System; University of California San Diego; University of California System; University of California San Diego; University of California System; University of California San Diego; US Department of Veterans Affairs; Veterans Health Administration (VHA); Salk Institute
NR 31
TC 339
Z9 374
U1 0
U2 3
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 544
EP 547
DI 10.1038/364544a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700060
PM 8336793
DA 2026-03-10
ER

PT J
AU SEUBERT, P
   OLTERSDORF, T
   LEE, MG
   BARBOUR, R
   BLOMQUIST, C
   DAVIS, DL
   BRYANT, K
   FRITZ, LC
   GALASKO, D
   THAL, LJ
   LIEBERBURG, I
   SCHENK, DB
AF SEUBERT, P
   OLTERSDORF, T
   LEE, MG
   BARBOUR, R
   BLOMQUIST, C
   DAVIS, DL
   BRYANT, K
   FRITZ, LC
   GALASKO, D
   THAL, LJ
   LIEBERBURG, I
   SCHENK, DB
TI SECRETION OF BETA-AMYLOID PRECURSOR PROTEIN CLEAVED AT THE AMINO TERMINUS OF THE BETA-AMYLOID PEPTIDE
SO NATURE
LA English
DT Article
ID alzheimers-disease; domain; identification; mutation; gene
AB THE accumulation in brain of senile plaques containing beta-amyloid protein (Abeta) is a defining feature of Alzheimer's disease1-3. The amyloid precursor protein (APP)4 from which Abeta is derived is subject to several genetic mutations which segregate with rare familial forms of the disease, resulting in early onset of dementia and plaque formation5-9, suggesting that APP metabolism plays a causal role in the disease. Various cell types have been shown to release a soluble form of Abeta, thus allowing for the in vitro study of Abeta generation10-12. We report here evidence that a substantial portion of the APP secreted by human mixed brain cell cultures, as well as that present in cerebrospinal fluid, is of a novel form cleaved precisely at the amino terminus of Abeta, suggesting that a secretory pathway is involved in Abeta genesis.
C1 UNIV CALIF SAN DIEGO,DEPT NEUROSCI,LA JOLLA,CA 92093.
   VET ADM MED CTR,SAN DIEGO,CA 92161.
C3 University of California System; University of California San Diego; US Department of Veterans Affairs; Veterans Health Administration (VHA)
RP SEUBERT, P (corresponding author), ATHENA NEUROSCI INC,800F GATEWAY BLVD,SAN FRANCISCO,CA 94080, USA.
NR 26
TC 523
Z9 626
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 260
EP 263
DI 10.1038/361260a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400060
PM 7678698
DA 2026-03-10
ER

PT J
AU PFEIFER, JD
   WICK, MJ
   ROBERTS, RL
   FINDLAY, K
   NORMARK, SJ
   HARDING, CV
AF PFEIFER, JD
   WICK, MJ
   ROBERTS, RL
   FINDLAY, K
   NORMARK, SJ
   HARDING, CV
TI PHAGOCYTIC PROCESSING OF BACTERIAL-ANTIGENS FOR CLASS-I MHC PRESENTATION TO T-CELLS
SO NATURE
LA English
DT Article
ID membrane protein; lymphocytes-t; salmonella; induction; molecules; topology; surface; epitope; invivo
AB CLASS I major histocompatibility complex (MHC) molecules present antigens that are produced within the presenting cell or penetrate from the vacuolar system into the cytosol for processing. Most studies of exogenous antigen processing have used soluble antigens, which are not efficiently presented by class I MHC molecules1 and do not elicit CD8 T-cell responses in vivo. But particulate antigen preparations with no known mechanism for cytosolic penetration can also elicit CD8 T-cell responses in vivo2-7. We report here that phagocytosis of bacteria with no mechanism for cytosolic penetration also results in presentation of bacterial antigens by class I MHC molecules. Moreover, this mechanism is resistant to cycloheximide and Brefeldin A, which block the classical class I processing pathway. These results suggest a novel vacuolar class I processing pathway for exogenous phagocytic antigens.
C1 WASHINGTON UNIV,SCH MED,DEPT PATHOL,ST LOUIS,MO 63110.
   WASHINGTON UNIV,SCH MED,DEPT MOLEC MICROBIOL,ST LOUIS,MO 63110.
C3 Washington University (WUSTL); Washington University (WUSTL)
NR 31
TC 572
Z9 644
U1 0
U2 13
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 359
EP 362
DI 10.1038/361359a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000060
PM 7678924
DA 2026-03-10
ER

PT J
AU DEKKER, N
   COX, M
   BOELENS, R
   VERRIJZER, CP
   VANDERVLIET, PC
   KAPTEIN, R
AF DEKKER, N
   COX, M
   BOELENS, R
   VERRIJZER, CP
   VANDERVLIET, PC
   KAPTEIN, R
TI SOLUTION STRUCTURE OF THE POU-SPECIFIC DNA-BINDING DOMAIN OF OCT-1
SO NATURE
LA English
DT Article
ID nuclear-magnetic-resonance; transcription factors; distance constraints; crystal-structure; factor-iii; protein; replication; sequence; complex
AB THE transcription factor Oct-1 belongs to a family containing a POU DNA-binding domain. This bipartite domain is composed of a POU-specific domain (POU(s)) and a POU-homeodomain (POU(hd)) connected by a flexible linker. The left half of the optimal POU binding site, the octamer ATGCAAAT, is recognized by POU(s) and the right half by POU(hd). We have determined the solution structure of POU(s) by nuclear magnetic resonance. It consists of four alpha-helices connected by short loops. Helices I and IV are in a parallel coiled-coil arrangement. The folding topology appears to be similar to that of the bacteriophage lambda-repressor and 434 repressor. For the well defined parts of the protein (residues 1-71), the average root-mean square deviation for the backbone atoms is 0.9 angstrom. Based on the observed selective exchange broadening in the (N-15, H-1)-HMQC (heteronuclear multiple quantum coherence) spectrum of the POU(s)-DNA complex we conclude that DNA-binding is mediated by helix III. We propose a model for the POU-DNA complex in which both recognition helices from the two subdomains have adjacent positions in the major groove.
C1 UNIV UTRECHT,BIJVOET CTR BIOMOLEC RES,3584 CH UTRECHT,NETHERLANDS.
   UNIV UTRECHT,PHYSIOL CHEM LAB,3521 GG UTRECHT,NETHERLANDS.
C3 Utrecht University; Utrecht University
NR 26
TC 140
Z9 155
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 852
EP 855
DI 10.1038/362852a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300061
PM 8479524
DA 2026-03-10
ER

PT J
AU WU, L
   RUSSELL, P
AF WU, L
   RUSSELL, P
TI NIM1 KINASE PROMOTES MITOSIS BY INACTIVATING WEE1 TYROSINE KINASE
SO NATURE
LA English
DT Article
ID fission yeast; protein-kinase; schizosaccharomyces-pombe; activates p34cdc2; mitotic inducer; cdc25 protein; phosphorylation; phosphatase; cells; gene
AB IN most species, including the fission yeast Schizosaccharomyces pombe, the Cdc2/cyclin B mitosis-inducing kinase is maintained in an inhibited state during interphase as a result of phosphorylation of a tyrosine residue in the ATP-binding region of Cdc2 (refs 1-3). This site is phosphorylated by Wee1 kinase4-9 and dephosphorylated by Cdc25 phosphatase10-15. In fission yeast an additional element of the G2/M control Nim1/Cdr1 kinase, has been identified which functions as a potent mitotic inducer16,17. These studies suggested that Nim1 acts by inhibiting Wee1, perhaps by direct phosphorylation. Consistent with this model, we report here that Wee1 is hyperphosphorylated in cells that overproduce Nim1. Likewise, Weel phosphorylation is reduced in nim1- cells. Highly purified Nim1 kinase phosphorylates Wee1 in vitro, resulting in strong inhibition of Weel kinase. These observations show that Nim1 promotes the onset of mitosis by inhibiting Wee1.
C1 SCRIPPS RES INST, DEPT MOLEC BIOL, LA JOLLA, CA 92037 USA.
   Scripps Res Inst, DEPT CELL BIOL, LA JOLLA, CA 92037 USA.
C3 Scripps Research Institute; Scripps Research Institute
NR 26
TC 140
Z9 165
U1 0
U2 6
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 738
EP 741
DI 10.1038/363738a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900061
PM 8515818
DA 2026-03-10
ER

PT J
AU BEKKI, S
   TOUMI, R
   PYLE, JA
AF BEKKI, S
   TOUMI, R
   PYLE, JA
TI ROLE OF SULFUR PHOTOCHEMISTRY IN TROPICAL OZONE CHANGES AFTER THE ERUPTION OF MOUNT PINATUBO
SO NATURE
LA English
DT Article
ID stratosphere; chemistry
AB RECENT observations suggest that the eruption of Mount Pinatubo in June 1991 has had a considerable effect on ozone concentrations in the tropical stratosphere (refs 1, 2, and J. W. Waters, personal communication). Although stratospheric ozone losses following volcanic eruptions are generally attributed to the presence of sulphate aerosol3-7, we present model calculations which demonstrate that gas-phase sulphur chemistry may have played a part in the tropical ozone perturbations that followed the Pinatubo eruption. We find that in the first month or so after the eruption, the large amount of SO2 injected into the tropical atmosphere catalyses mid-stratospheric ozone production. On the other hand, the SO2 cloud absorbs solar radiation, thereby reducing the rate of O2 photolysis (and hence of ozone production) below it. These two effects cancel each other out at an altitude of about 25 kilometres. After one or two months, most of the SO2 has been oxidized to sulphate; the efficiency of these two mechanisms then becomes negligible (although ozone remains perturbed in the lower stratosphere because of its long photochemical lifetime in this region). The model features show good agreement with initial ozone measurements following the eruption, including both the mid-altitude switch from ozone loss to ozone gain1, and the increase and subsequent decrease in the total ozone column2,7.
RP BEKKI, S (corresponding author), UNIV CAMBRIDGE,DEPT CHEM,CTR ATMOSPHER SCI,LENSFIELD RD,CAMBRIDGE CB2 1EW,ENGLAND.
NR 21
TC 44
Z9 47
U1 2
U2 17
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 331
EP 333
DI 10.1038/362331a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600055
PM 29634037
DA 2026-03-10
ER

PT J
AU TSELIOUDIS, G
   LACIS, AA
   RIND, D
   ROSSOW, WB
AF TSELIOUDIS, G
   LACIS, AA
   RIND, D
   ROSSOW, WB
TI POTENTIAL EFFECTS OF CLOUD OPTICAL-THICKNESS ON CLIMATE WARMING
SO NATURE
LA English
DT Article
ID feedback; sensitivity; model
AB CLIMATE warming can cause changes in the optical properties of low clouds, which may in turn amplify or diminish the warming1,2. But both the sign and magnitude of such feedbacks have been uncertain, largely because the observational evidence for variations in the large-scale optical properties of clouds has been very limited. Recently, analysis of data from the International Satellite Cloud Climatology Project yielded a relationship between low-cloud optical thickness and cloud temperature that implies a positive feed-back between clouds and climate3. Here we use a two-dimensional radiative-convective model to assess the effect of such a feedback on the climate change associated with a doubling of the atmospheric carbon dioxide concentration. We find that, zonally averaged, the feedback is positive in the Northern Hemisphere and is stronger at lower than at higher latitudes. The positive feedback amplifies the overall global climate sensitivity, and the latitudinal gradient in the strength of the feedback acts to eliminate the high-latitude amplification of the greenhouse warming predicted by most climate models.
C1 COLUMBIA UNIV,NEW YORK,NY 10027.
C3 Columbia University
RP TSELIOUDIS, G (corresponding author), NASA,GODDARD INST SPACE STUDIES,2880 BROADWAY,NEW YORK,NY 10025, USA.
NR 15
TC 20
Z9 23
U1 1
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 670
EP 672
DI 10.1038/366670a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500064
DA 2026-03-10
ER

PT J
AU TABCHARANI, JA
   ROMMENS, JM
   HOU, YX
   CHANG, XB
   TSUI, LC
   RIORDAN, JR
   HANRAHAN, JW
AF TABCHARANI, JA
   ROMMENS, JM
   HOU, YX
   CHANG, XB
   TSUI, LC
   RIORDAN, JR
   HANRAHAN, JW
TI MULTIION PORE BEHAVIOR IN THE CFTR CHLORIDE CHANNEL
SO NATURE
LA English
DT Article
ID cystic-fibrosis gene; calcium channels; conductance; cells; selectivity; mutagenesis; expression; invitro
AB CYSTIC fibrosis transmembrane conductance regulator (CFTR) is a non-rectifying, low-conductance channel1,2 regulated by ATP3 and phosphorylation, which mediates apical chloride conductance in secretory epithelia5,6 and malfunctions in cystic fibrosis (CF)7,8. Mutations at Lys 335 and Arg 347 in the sixth predicted transmembrane helix of CFTR alter its halide selectivity in whole-cell studies9 and its single channel conductance10, but the physical basis of these alterations is unknown and permeation in CFTR is poorly understood. Here we present evidence that wild-type CFTR can contain more than one anion simultaneously. The conductance of CFTR passes through a minimum when channels are bathed in mixtures of two permeant anions. This anomalous mole fraction effect can be abolished by replacing Arg 347 with an aspartate and can be toggled on or off by varying the pH after the same residue is replaced with a histidine. Thus the CFTR channel should provide a convenient model in which to study multi-ion pore behaviour and conduction. The loss of multiple occupancy may explain how naturally occurring CF mutations at this site cause disease.
C1 MCGILL UNIV,DEPT PHYSIOL,3655 DRUMMOND ST,MONTREAL H3G 1Y6,QUEBEC,CANADA.
   UNIV TORONTO,DEPT MOLEC & MED GENET,TORONTO M5S 1A1,ONTARIO,CANADA.
   UNIV TORONTO,DEPT BIOCHEM & CLIN BIOCHEM,TORONTO M5S 1A1,ONTARIO,CANADA.
   HOSP SICK CHILDREN,RES INST,TORONTO M5G 1X8,ONTARIO,CANADA.
C3 McGill University; University of Toronto; University of Toronto; University of Toronto; Hospital for Sick Children (SickKids)
NR 21
TC 212
Z9 227
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 79
EP 82
DI 10.1038/366079a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700059
PM 7694154
DA 2026-03-10
ER

PT J
AU DAMSTE, JSS
   WAKEHAM, SG
   KOHNEN, MEL
   HAYES, JM
   DELEEUW, JW
AF DAMSTE, JSS
   WAKEHAM, SG
   KOHNEN, MEL
   HAYES, JM
   DELEEUW, JW
TI A 6,000-YEAR SEDIMENTARY MOLECULAR RECORD OF CHEMOCLINE EXCURSIONS IN THE BLACK-SEA
SO NATURE
LA English
DT Article
ID photosynthesis; diagenesis
AB THE Black Sea is the world's largest anoxic basin; it is also a contemporary analogue of the environment in which carbonaceous shales and petroleum source beds formed1. Recently, Repeta et al.2,3 reported that anoxygenic photosynthesis may be an important component of carbon cycling in the present Black Sea, owing to a shoaling of the chemocline and consequent penetration of the photic zone by anaerobic waters in the past few decades4,5. It has been suggested4 that this was due to an anthropogenic decrease in freshwater input to the Black Sea, although natural causes were not ruled out. Here we report the distributions of sequestered photosynthetic pigments in eight core samples of sediments from the Black Sea ranging in age from zero to 6,200 years before the present. Our results show that photosynthetic green sulphur bacteria (Clorobiaceae) have been active in the Black Sea for substantial periods of time in the past. This finding indicates that the penetration of the photic zone by anaerobic waters is not a recent phenomenon, and suggests that natural causes for shoaling of the chemocline are more likely than anthropogenic ones4.
C1 DELFT UNIV TECHNOL,ORGAN GEOCHEM UNIT,2628 RZ DELFT,NETHERLANDS.
   SKIDAWAY INST OCEANOG,SAVANNAH,GA 31416.
   INDIANA UNIV,DEPT GEOL SCI,BIOGEOCHEM LABS,BLOOMINGTON,IN 47405.
   INDIANA UNIV,DEPT CHEM,BLOOMINGTON,IN 47405.
C3 Delft University of Technology; University System of Georgia; University of Georgia; Skidaway Institute of Oceanography; Indiana University System; Indiana University Bloomington; Indiana University System; Indiana University Bloomington
RP DAMSTE, JSS (corresponding author), NETHERLANDS INST SEA RES,DIV MARINE BIOGEOCHEM,POB 59,1790 AB DEN BURG,NETHERLANDS.
NR 21
TC 211
Z9 221
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 827
EP 829
DI 10.1038/362827a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300051
PM 11536532
DA 2026-03-10
ER

PT J
AU MEHLER, MF
   ROZENTAL, R
   DOUGHERTY, M
   SPRAY, DC
   KESSLER, JA
AF MEHLER, MF
   ROZENTAL, R
   DOUGHERTY, M
   SPRAY, DC
   KESSLER, JA
TI CYTOKINE REGULATION OF NEURONAL DIFFERENTIATION OF HIPPOCAMPAL PROGENITOR CELLS
SO NATURE
LA English
DT Article
ID monoclonal-antibody; cholinergic neurons; nervous-system; growth; interleukin-11; neurofilaments; invitro; insitu; invivo; line
AB THE signalling mechanisms governing haematolymphopoiesis and those regulating neural development may be closely related, as indicated by similarities of higher-order structure and function of the cytokines involved1, of the regional and temporal regulation of their transcription and translation2-6, and of their bioactivity7-10. Here we investigate this possible evolutionary connection using retroviral transduction of a temperature-sensitive mutant form of the SV40 large T antigen to develop conditionally immortalized murine embryonic hippocampal progenitor cell lines11-14. Treatment of these cells with cytokines that are thought to participate in progressive lymphoid maturation, immunoglobulin synthesis15-18 and erythropoiesis19,20 causes progressive neuronal differentiation, as defined by morphological criteria, successive expression of increasingly mature neurofilament proteins21-23, and the generation of inward currents and action potentials. The cytokine interleukin(IL)-11 induces expression of action potentials that are insensitive to tetrodotoxin, which is indicative of developmentally immature sodium channels24. By contrast, for expression of more mature action potentials24 (tetrodotoxin-sensitive) one of the interleukins IL-5, IL-7 or IL-9 must be applied in association with transforming growth factor-alpha after pretreatment with basic fibroblast growth factor. Our results suggest that the mechanisms regulating lineage commitment and cellular differentiation in the neural and haematopoietic systems are similar. Further, they define an in vitro model system that may facilitate molecular analysis of graded stages of mammalian neuronal differentiation.
C1 YESHIVA UNIV ALBERT EINSTEIN COLL MED,DEPT NEUROSCI,BRONX,NY 10461.
   FED UNIV RIO DE JANEIRO,INST BIOPHYS CARLOS CHAGAS FILHO,BR-21941 RIO JANEIRO,BRAZIL.
C3 Montefiore Medical Center; Albert Einstein College of Medicine; Yeshiva University
RP MEHLER, MF (corresponding author), YESHIVA UNIV ALBERT EINSTEIN COLL MED,DEPT NEUROL,BRONX,NY 10461, USA.
NR 30
TC 236
Z9 254
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 62
EP 65
DI 10.1038/362062a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600060
PM 8383296
DA 2026-03-10
ER

PT J
AU NISHIZAKA, T
   YAGI, T
   TANAKA, Y
   ISHIWATA, S
AF NISHIZAKA, T
   YAGI, T
   TANAKA, Y
   ISHIWATA, S
TI RIGHT-HANDED ROTATION OF AN ACTIN FILAMENT IN AN INVITRO MOTILE SYSTEM
SO NATURE
LA English
DT Article
ID myosin; movement; muscle
AB MUSCLE contraction occurs by mutual sliding between thick (myosin) and thin (actin) filaments1,2. But the physical and chemical properties of the sliding force are not clear; even the precise direction of sliding force generated at each cross-bridge is not known. We report here the use of a recently developed in vitro motile assay system3-5 to show supercoiling of an actin filament in which the front part of the filament was fixed to a glass surface through cross-linked heavy-meromyosin and the rear part was able to slide on a track of heavy-meromyosin. A left-handed single turn of superhelix formed just before supercoiling, suggesting that the sliding force has a right-handed torque component that induces the right-handed rotation of an actin filament around its long axis. The presence of the torque component in the sliding force will explain several properties of the contractile system of muscle.
C1 WASEDA UNIV,SCH SCI & ENGN,DEPT PHYS,3-4-1 OKUBO,SHINJUKU KU,TOKYO 169,JAPAN.
   HONDA RES & DEV CO LTD,WAKO RES CTR,SAITAMA 35101,JAPAN.
C3 Waseda University; Honda Motor Company
NR 18
TC 117
Z9 126
U1 0
U2 12
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 269
EP 271
DI 10.1038/361269a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400063
PM 8423853
DA 2026-03-10
ER

PT J
AU HAMERSCASTERMAN, C
   ATARHOUCH, T
   MUYLDERMANS, S
   ROBINSON, G
   HAMERS, C
   SONGA, EB
   BENDAHMAN, N
   HAMERS, R
AF HAMERSCASTERMAN, C
   ATARHOUCH, T
   MUYLDERMANS, S
   ROBINSON, G
   HAMERS, C
   SONGA, EB
   BENDAHMAN, N
   HAMERS, R
TI NATURALLY-OCCURRING ANTIBODIES DEVOID OF LIGHT-CHAINS
SO NATURE
LA English
DT Article
ID immunoglobulin heavy-chain; variant surface glycoprotein; escherichia-coli; segmental flexibility; trypanosoma-brucei; binding-protein; generation; differentiation; repertoire; molecules
AB RANDOM association of VL and VH repertoires contributes considerably to antibody diversity1. The diversity and the affinity are then increased by hypermutation in B cells located in germinal centres2. Except in the case of 'heavy chain' disease3, naturally occurring heavy-chain antibodies have not been described, although antigen binding has been demonstrated for separated heavy chains4 or cloned VH domains5. Here we investigate the presence of considerable amounts of IgG-like material of M(r) 100K in the serum of the camel (Camelus dromedarius)6. These molecules are composed of heavy-chain dimers and are devoid of light chains, but nevertheless have an extensive antigen-binding repertoire, a finding that calls into question the role of light chains in the camel. Camel heavy-chain IgGs lack CH1, which in one IgG class might be structurally replaced by an extended hinge. Heavy-chain IgGs are a feature of all camelids. These findings open new perspectives in the engineering of antibodies.
C1 VRIJE UNIV BRUSSELS, INST MOLEC BIOL, PAARDENST 65, B-1640 RHODE ST GENESE, BELGIUM.
   UNIV DUBLIN TRINITY COLL, DEPT BIOCHEM, DUBLIN 2, IRELAND.
C3 Vrije Universiteit Brussel; Trinity College Dublin
NR 26
TC 2613
Z9 4154
U1 20
U2 686
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 446
EP 448
DI 10.1038/363446a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800057
PM 8502296
DA 2026-03-10
ER

PT J
AU WIDDEL, F
   SCHNELL, S
   HEISING, S
   EHRENREICH, A
   ASSMUS, B
   SCHINK, B
AF WIDDEL, F
   SCHNELL, S
   HEISING, S
   EHRENREICH, A
   ASSMUS, B
   SCHINK, B
TI FERROUS IRON OXIDATION BY ANOXYGENIC PHOTOTROPHIC BACTERIA
SO NATURE
LA English
DT Article
ID photosynthesis; reduction
AB NATURAL oxidation of ferrous to ferric iron by bacteria such as Thiobacillus ferrooxidans or Gallionella ferruginea1, or by chemical oxidation2,3 has previously been thought always to involve molecular oxygen as the electron acceptor. Anoxic photochemical reactions4-6 or a photobiological process involving two photosystems7-9 have also been discussed as mechanisms of ferrous iron oxidation. The knowledge of such processes has implications that bear on our understanding of the origin of Precambrian banded iron formations10-14. The reducing power of ferrous iron increases dramatically at pH values higher than 2-3 owing to the formation of ferric hydroxy and oxyhydroxy compounds1,2,15 (Fig. 1). The standard redox potential of Fe3+/Fe2+ (E0 = +0.77 V) is relevant only under acidic conditions. At pH 7.0, the couples Fe(OH)3/Fe2+ (E0' = -0.236 V) or Fe(OH)3 + HCO3-/FeCO3 (E0' = +0.200 V) prevail, matching redox potentials measured in natural sediments9,16,17. It should thus be possible for Fe(II) around pH 7.0 to function as an electron donor for anoxygenic photosynthesis. The midpoint potential of the reaction centre in purple bacteria is around +0.45 V (ref. 18). Here we describe purple, non-sulphur bacteria that can indeed oxidize colourless Fe(II) to brown Fe(III) and reduce CO2 to cell material, implying that oxygen-independent biological iron oxidation was possible before the evolution of oxygenic photosynthesis.
C1 UNIV CONSTANCE,FAK BIOL,POSTFACH 5560,W-7750 CONSTANCE,GERMANY.
   MAX PLANCK INST MARINE MIKROBIOL,W-2800 BREMEN,GERMANY.
C3 University of Konstanz; Max Planck Society
NR 27
TC 554
Z9 673
U1 3
U2 273
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 834
EP 836
DI 10.1038/362834a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300054
DA 2026-03-10
ER

PT J
AU KOBE, B
   DEISENHOFER, J
AF KOBE, B
   DEISENHOFER, J
TI CRYSTAL-STRUCTURE OF PORCINE RIBONUCLEASE INHIBITOR, A PROTEIN WITH LEUCINE-RICH REPEATS
SO NATURE
LA English
DT Article
ID kinetic characterization; transmembrane protein; gene; drosophila; cerevisiae; sequence; homology; domains; cyclase; yeast
AB RIBONUCLEASE inhibitor is a cytoplasmic protein that tightly binds and inhibits ribonucleases of the pancreatic ribonuclease superfamily1. The primary sequence of this inhibitor contains leucine-rich repeats2 (LRRs); these motifs are present in many proteins that participate in protein-protein interactions and have different functions and cellular locations. In vivo, ribonuclease inhibitor may have a role in the regulation of RNA turnover in mammalian cells3 and in angiogenesis4. To define the structural features of LRR proteins and to understand better the nature of the tight interaction of ribonuclease inhibitor with ribonucleases, we have determined the crystal structure of the porcine inhibitor. To our knowledge, this is the first three-dimensional structure of a protein containing LRRs and represents a new class of alpha/beta protein fold. Individual repeats constitute beta-alpha structural units that probably also occur in other proteins containing LRRs. The non-globular shape of the structure and the exposed face of the parallel beta-sheet may explain why LRRs are used to achieve strong protein-protein interactions. A possible ribonuclease-binding region incorporates the surface formed by the parallel beta-sheet and the betaalpha loops.
C1 UNIV TEXAS,SW MED CTR,DEPT BIOCHEM,DALLAS,TX 75235.
C3 University of Texas System; University of Texas Southwestern Medical Center; University of Texas Dallas
RP KOBE, B (corresponding author), UNIV TEXAS,SW MED CTR,HOWARD HUGHES MED INST,5323 HARRY HINES BLVD,DALLAS,TX 75235, USA.
NR 40
TC 548
Z9 605
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 23
PY 1993
VL 366
IS 6457
BP 751
EP 756
DI 10.1038/366751a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MN264
UT WOS:A1993MN26400031
PM 8264799
DA 2026-03-10
ER

PT J
AU GHADIRI, MR
   GRANJA, JR
   MILLIGAN, RA
   MCREE, DE
   KHAZANOVICH, N
AF GHADIRI, MR
   GRANJA, JR
   MILLIGAN, RA
   MCREE, DE
   KHAZANOVICH, N
TI SELF-ASSEMBLING ORGANIC NANOTUBES BASED ON A CYCLIC PEPTIDE ARCHITECTURE
SO NATURE
LA English
DT Article
ID molecular-sieve; gramicidin-a; nanochemistry; microtubules; proteins; carbon; pore
AB HOLLOW tubular structures of molecular dimensions may offer a variety of applications in chemistry, biochemistry and materials science. Concentric carbon nanotubes1,2 have attracted a great deal of attention, while the three-dimensional tubular pore structures of molecular sieves have long been exploited industrially3-8. Nanoscale tubes based on organic materials have also been reported previously9-13. Here we report the design, synthesis and characterization of a new class of organic nanotubes based on rationally designed cyclic polypeptides. When protonated, these compounds crystallize into tubular structures hundreds of nanometres long, with internal diameters of 7-8 angstrom. Support for the proposed tubular structures is provided by electron microscopy, electron diffraction, Fourier-transform infrared spectroscopy and molecular modelling. These tubes are open-ended, with uniform shape and internal diameter. We anticipate that they may have possible applications in inclusion chemistry, catalysis, molecular electronics and molecular separation technology.
C1 SCRIPPS RES INST, DEPT MOLEC BIOL, LA JOLLA, CA 92307 USA.
   Scripps Res Inst, DEPT CELL BIOL, LA JOLLA, CA 92307 USA.
C3 Scripps Research Institute; Scripps Research Institute
RP GHADIRI, MR (corresponding author), SCRIPPS RES INST, DEPT CHEM, LA JOLLA, CA 92307 USA.
NR 27
TC 1570
Z9 1750
U1 12
U2 558
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 324
EP 327
DI 10.1038/366324a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500042
PM 8247126
DA 2026-03-10
ER

PT J
AU WRACHTRUP, J
   VONBORCZYSKOWSKI, C
   BERNARD, J
   ORRIT, M
   BROWN, R
AF WRACHTRUP, J
   VONBORCZYSKOWSKI, C
   BERNARD, J
   ORRIT, M
   BROWN, R
TI OPTICAL-DETECTION OF MAGNETIC-RESONANCE IN A SINGLE MOLECULE
SO NATURE
LA English
DT Article
ID para-terphenyl crystal; fluorescence excitation; pentacene molecules; triplet-state; spectroscopy
AB MAGNETIC resonance spectroscopy1 is a powerful tool for molecular characterization and structure determination. The sensitivity of conventional approaches is limited to about 10(10) electron spins or 10(16) nuclear spins; this sensitivity can be improved to about 10(5) spins by polarizing the spins via optical pumping and detecting optical rather than microwave photons2. Recently, fluorescence from single molecules was detected by tuning a single-frequency laser in the inhomogeneously broadened fluorescence excitation band of a dilute dispersion of pentacene in a host crystal of p-terphenyl3,4. Here we report that, by combining single-molecule fluorescence spectroscopy with optically detected magnetic resonance for the pentacene-doped p-terphenyl system, we can detect magnetic resonance in a single pentacene molecule. We observe two of the three possible transitions between sublevels of the metastable triplet state. The spectral lineshapes indicate that the proton nuclear spin states change during the measurement, leading to spectral diffusion within the magnetic resonance line.
C1 UNIV BORDEAUX 1, CTR PHYS MOLEC OPT & HERTZIENNE, CNRS, UA 283, F-33405 TALENCE, FRANCE.
C3 Universite de Bordeaux; Centre National de la Recherche Scientifique (CNRS)
RP WRACHTRUP, J (corresponding author), FREE UNIV BERLIN, FACHBEREICH PHYS, ARNIMALLEE 14, W-1000 BERLIN 33, GERMANY.
NR 13
TC 278
Z9 316
U1 5
U2 116
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 244
EP 245
DI 10.1038/363244a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600045
DA 2026-03-10
ER

PT J
AU BRANCH, P
   AQUILINA, G
   BIGNAMI, M
   KARRAN, P
AF BRANCH, P
   AQUILINA, G
   BIGNAMI, M
   KARRAN, P
TI DEFECTIVE MISMATCH BINDING AND A MUTATOR PHENOTYPE IN CELLS TOLERANT TO DNA DAMAGE
SO NATURE
LA English
DT Article
ID escherichia-coli dna; o-6-methylguanine-dna methyltransferase; cho cells; repair; gene; methylnitrosourea; resistance; locus
AB ACQUIRED resistance to alkylating agents such as N-methyl-N-nitrosourea or N-methyl-N'-nitro-N-nitrosoguanidine results from the ability to tolerate the potentially cytotoxic methylated base O6-methylguanine (m6-G) in DNA. In the absence of repair by demethylation in situ, m6-G is probably lethal through its inappropriate processing by the cell1. DNA mismatch correction is an attractive candidate for the processing function because although it is replicated, m6-G has no perfect complementary base. Thus, m6-G in DNA might provoke abortive mismatch repair and tolerance could subsequently arise through loss of a mismatch repair pathway2-3. Mismatch correction helps maintain genomic fidelity by removing misincorporated bases and deaminated 5-methylcytosine from DNA, and its loss by mutation confers a mutator phenotype on Escherichia coli4,5. Here we describe human and hamster cell lines that are tolerant to N-methyl-N-nitrosourea and are defective in a DNA mismatch binding activity. The loss of this activity, which acts on G.T mispairs, confers a mutator phenotype.
C1 IMPERIAL CANC RES FUND,CLARE HALL LABS,S MIMMS EN6 3LD,HERTS,ENGLAND.
   IST SUPER SANITA,I-00161 ROME,ITALY.
C3 Istituto Superiore di Sanita (ISS)
NR 21
TC 353
Z9 380
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 652
EP 654
DI 10.1038/362652a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800055
PM 8464518
DA 2026-03-10
ER

PT J
AU POSTORINO, P
   TROMP, RH
   RICCI, MA
   SOPER, AK
   NEILSON, GW
AF POSTORINO, P
   TROMP, RH
   RICCI, MA
   SOPER, AK
   NEILSON, GW
TI THE INTERATOMIC STRUCTURE OF WATER AT SUPERCRITICAL TEMPERATURES
SO NATURE
LA English
DT Article
ID molecular-dynamics; liquid water; simulation; scattering
AB LIQUID water, the medium in which life both began and persists, is in many ways a most unusual fluid. Much is known about the macroscopic properties of the condensed and gaseous states of water, but our understanding of the microscopic forces that define water structure remains incomplete1. This structure, described in terms of correlations between the pairs of atoms O-H, O-O and H-H (ref. 2), can be studied by neutron diffraction techniques involving isotopic substitution3. In particular, the signature of hydrogen bonding is apparent in neutron diffraction experiments as a peak in the pair correlation function of O and H (g(OH)(r)) at about 1.9 angstrom (refs 3, 4). Here we extend such studies into the supercritical regime of water, in which there is no longer any distinction between the liquid and vapour phases. We find that at the supercritical temperature of 400-degrees-C almost all hydrogen bonding is broken down, even though the thermal energy k(B)T is considerably less than the energy of the hydrogen bond. Our results are markedly different from the predictions of computer simulations under comparable conditions5 using a common model of water5-7. Our results provide a sensitive test of models of water structure more generally, and give some indication of the environment that solute molecules will experience in extraction and reaction processes that employ supercritical water as a solvent8.
C1 UNIV BRISTOL,HH WILLS PHYS LAB,TYNDALL AVE,BRISTOL BS8 1TL,AVON,ENGLAND.
   UNIV ROMA 3,DIPARTIMENTO FIS E AMALDI,I-00154 ROME,ITALY.
   UNIV ROMA LA SAPIENZA,DIPARTIMENTO FIS,I-00185 ROME,ITALY.
   RUTHERFORD APPLETON LAB,DIV NEUTRON,DIDCOT OX11 0QX,OXON,ENGLAND.
C3 University of Bristol; Roma Tre University; Sapienza University Rome; UK Research & Innovation (UKRI); Science & Technology Facilities Council (STFC); STFC Rutherford Appleton Laboratory
NR 18
TC 256
Z9 269
U1 1
U2 73
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 668
EP 670
DI 10.1038/366668a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500063
DA 2026-03-10
ER

PT J
AU SINGH, J
   KLAR, AJS
AF SINGH, J
   KLAR, AJS
TI DNA POLYMERASE-ALPHA IS ESSENTIAL FOR MATING-TYPE SWITCHING IN FISSION YEAST
SO NATURE
LA English
DT Article
ID schizosaccharomyces-pombe; replication; genes; cells; initiation; asymmetry; strands; pattern; site; mat1
AB IN the fission yeast Schizosaccharomyces pombe, the double-stranded chromosomal break (DSB) at the mating-type locus (mat1) initiates recombination during mating-type switching1-3 . A constant DSB level is maintained throughout the cell-cycle'. In the strand-segregation model for mating-type switching, it was postulated that if the DSB is generated during or soon after mat1 replication4, one of the chromatids could be repaired and switched during replication in the next cell cycle, while the other chromatid inherits the break3-6. Here we report a molecular characterization of swi7, one of the genes required for DSB formation. Surprisingly, a gene complementing the swi7 mutation maps to chromosome I and encodes S. pombe DNA polymerase-alpha. Disruption of this gene is lethal in both switching and non-switching strains, as expected. S. pombe DNA polymerase-alpha must therefore play a role in generating the DSB at mat1, suggesting that DSB formation is coupled with DNA replication.
C1 NCI, FREDERICK CANC RES & DEV CTR, ABL BASIC RES PROGRAM,EUKARYOT GENE EXPRESS LAB, POB B,BLDG 539, FREDERICK, MD 21702 USA.
C3 Science Applications International Corporation (SAIC); SAIC-Frederick; National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI)
NR 28
TC 63
Z9 65
U1 0
U2 1
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 271
EP 273
DI 10.1038/361271a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400064
PM 8423854
DA 2026-03-10
ER

PT J
AU MESZAROS, LG
   BAK, J
   CHU, A
AF MESZAROS, LG
   BAK, J
   CHU, A
TI CYCLIC ADP-RIBOSE AS AN ENDOGENOUS REGULATOR OF THE NONSKELETAL TYPE RYANODINE RECEPTOR CA2+ CHANNEL
SO NATURE
LA English
DT Article
ID ca-2+ release channel; sarcoplasmic-reticulum; calcium release; muscle; membranes; conductance; activation; metabolite; mechanism; binding
AB THE skeletal and cardiac isoforms1 of the ryanodine receptor Ca2+ channel (RyRC) constitute the Ca2+ release pathway in sarcoplasmic reticulum of skeletal and cardiac muscles, respectively2,3. A direct mechanical and a Ca2+-triggered mechanism (Ca2+-induced Ca2+ release) have been respectively proposed to explain the in situ activation of Ca2+ release in skeletal and cardiac muscle4,5. In non-muscle cells, however, where the RyRC also participates in Ca2+ signalling6-11 the mechanism of RyRC activation is unknown. Cyclic adenosine 5'-diphosphoribose (cADPR)12, which is present in many mammalian tissues13, has been reported to induce Ca2+ release from ryanodine-sensitive intracellular Ca2+ stores in sea urchin eggs14. Here we provide evidence that cADPR directly activates the cardiac but not the skeletal isoform of the RyRC. This, together with results on sea urchin eggs14, suggests that cADPR is an endogenous activator of the non-skeletal type of RyRC and may thus have a role similar to inositol 1,4,5-trisphosphate15 in Ca2+ signalling.
C1 BAYLOR COLL MED,DEPT MED,HOUSTON,TX 77030.
C3 Baylor College of Medicine
RP MESZAROS, LG (corresponding author), MED COLL GEORGIA,DEPT PHYSIOL & ENDOCRINOL,AUGUSTA,GA 30912, USA.
NR 29
TC 341
Z9 360
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 76
EP 79
DI 10.1038/364076a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800062
PM 8391127
DA 2026-03-10
ER

PT J
AU KIM, YC
   GEIGER, JH
   HAHN, S
   SIGLER, PB
AF KIM, YC
   GEIGER, JH
   HAHN, S
   SIGLER, PB
TI CRYSTAL-STRUCTURE OF A YEAST TBP TATA-BOX COMPLEX
SO NATURE
LA English
DT Article
ID transcription factor; binding-protein; dna; domain; invivo; specificity; initiation; resolution; refinement; hydration
AB The 2.5 angstrom crystal structure of a TATA-box complex with yeast TBP shows that the eight base pairs of the TATA box bind to the concave surface of TBP by bending towards the major groove with unprecedented severity. This produces a wide open, underwound, shallow minor groove which forms a primarily hydrophobic interface with the entire under-surface of the TBP saddle. The severe bend and a positive writhe radically alter the trajectory of the flanking B-form DNA.
C1 YALE UNIV,DEPT MOLEC BIOPHYS & BIOCHEM,NEW HAVEN,CT 06510.
   YALE UNIV,HOWARD HUGHES MED INST,NEW HAVEN,CT 06510.
   FRED HUTCHINSON CANC RES CTR,SEATTLE,WA 98104.
C3 Yale University; Yale University; Howard Hughes Medical Institute; Fred Hutchinson Cancer Center
NR 47
TC 982
Z9 1101
U1 0
U2 38
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 512
EP 520
DI 10.1038/365512a0
PG 9
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100044
PM 8413604
DA 2026-03-10
ER

PT J
AU OTT, U
AF OTT, U
TI INTERSTELLAR GRAINS IN METEORITES
SO NATURE
LA English
DT Article
ID extinct superheavy element; s-process; murchison meteorite; silicon-carbide; allende meteorite; primitive chondrites; mass fractionation; isotopic anomaly; xenon; origin
AB Primitive meteorites contain grains of silicon carbide, graphite and diamond formed outside the Solar System and probably before its birth. The isotopic compositions of these grains provide a record of stellar nucleosynthesis and of condensation processes near carbon stars; the fact of their survival places constraints on conditions in the solar nebula and early Solar System. The search is now on for other surviving stellar condensates, such as nitrides and oxides.
RP OTT, U (corresponding author), MAX PLANCK INST CHEM, ISOTOPENKOSMOL ABT, JOH J BECHER WEG 27, POSTFACH 55020, D-55128 MAINZ, GERMANY.
NR 102
TC 169
Z9 173
U1 1
U2 11
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 25
EP 33
DI 10.1038/364025a0
PG 9
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800047
DA 2026-03-10
ER

PT J
AU PICCIRILLI, JA
   VYLE, JS
   CARUTHERS, MH
   CECH, TR
AF PICCIRILLI, JA
   VYLE, JS
   CARUTHERS, MH
   CECH, TR
TI METAL-ION CATALYSIS IN THE TETRAHYMENA RIBOZYME REACTION
SO NATURE
LA English
DT Article
ID phosphoryl-transfer-reactions; rna cleavage; endoribonuclease activity; thermophila ribozyme; kinetic description; escherichia-coli; dna; substrate; binding; site
AB ALL catalytic RNAs (ribozymes) require or are stimulated by divalent metal ions, but it has been difficult to separate the contribution of these metal ions to formation of the RNA tertiary structure1 from a more direct role in catalysis. The Tetrahymena ribozyme catalyses cleavage of exogenous RNA2,3 or DNA4,5 substrates with an absolute requirement for Mg2+ or Mn2+ (ref. 6). A DNA substrate, in which the bridging 3' oxygen atom at the cleavage site is replaced by sulphur, is cleaved by the ribozyme about 1,000 times more slowly than the corresponding unmodified DNA substrate when Mg2+ is present as the only divalent metal ion. But addition of Mn2+ or Zn2+ to the reaction relieves this negative effect, with the 3' S-P bond being cleaved nearly as fast as the 3' O-P bond. Considering that Mn2+ and Zn2+ coordinate sulphur more strongly than Mg2+ does7,8, these results indicate that the metal ion contributes directly to catalysis by coordination to the 3' oxygen atom in the transition state, presumably stabilizing the developing negative charge on the leaving group. We conclude that the Tetrahymena ribozyme is a metalloenzyme, with mechanistic similarities to several protein enzymes9-12.
C1 UNIV COLORADO, HOWARD HUGHES MED INST, BOULDER, CO 80309 USA.
   UNIV COLORADO, DEPT CHEM & BIOCHEM, BOULDER, CO 80309 USA.
C3 University of Colorado System; University of Colorado Boulder; Howard Hughes Medical Institute; University of Colorado System; University of Colorado Boulder
NR 39
TC 382
Z9 407
U1 2
U2 26
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 85
EP 88
DI 10.1038/361085a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800055
PM 8421499
DA 2026-03-10
ER

PT J
AU ERREDE, B
   GARTNER, A
   ZHOU, ZQ
   NASMYTH, K
   AMMERER, G
AF ERREDE, B
   GARTNER, A
   ZHOU, ZQ
   NASMYTH, K
   AMMERER, G
TI MAP KINASE-RELATED FUS3 FROM SACCHAROMYCES-CEREVISIAE IS ACTIVATED BY STE7 INVITRO
SO NATURE
LA English
DT Article
ID signal transduction; yeast; cln2; gene
AB PHEROMONE-STIMULATED haploid yeast cells undergo a differentiation process that allows them to mate1. Transmission of the intracellular signal involves threonine and tyrosine phosphorylation of the redundant FUS3 and KSS1 kinases, which are members. of the MAP kinase family2-4. FUS3/KSS1 phosphorylation depends on two additional kinases, STE11 and STE7 (refs 2, 5, 6). Genetic analyses predict an ordered pathway where STE11 acts before STE7 and FUS3/KSS1 (refs 2, 7). Here we report that STE7 is a dual-specificity kinase that modifies FUS3 at the appropriate sites and stimulates its catalytic activity in vitro. From these data and previous genetic results, we argue that STE7 is the physiological activator of FUS3. Recent indications that MA kinase activators are related to STE7 suggest that signal transduction pathways in many, if not all, eukaryotic organisms use homologous kinase cascades8-10.
C1 INST MOLEC PATHOL,A-1030 VIENNA,AUSTRIA.
   UNIV N CAROLINA,DEPT CHEM,CHAPEL HILL,NC 27599.
   UNIV VIENNA,INST ALLGEMEINE BIOCHEM,A-1030 VIENNA,AUSTRIA.
   UNIV VIENNA,LUDWIG BOLTZMANN FORSCHUNGSSTELLE,A-1030 VIENNA,AUSTRIA.
C3 Vienna Biocenter (VBC); Research Institute of Molecular Pathology (IMP); University of North Carolina; University of North Carolina Chapel Hill; University of Vienna; University of Vienna; Ludwig Boltzmann Institute
NR 21
TC 164
Z9 188
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 261
EP 264
DI 10.1038/362261a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600061
PM 8384702
DA 2026-03-10
ER

PT J
AU NABESHIMA, Y
   HANAOKA, K
   HAYASAKA, M
   ESUMI, E
   LI, SW
   NONAKA, I
   NABESHIMA, Y
AF NABESHIMA, Y
   HANAOKA, K
   HAYASAKA, M
   ESUMI, E
   LI, SW
   NONAKA, I
   NABESHIMA, Y
TI MYOGENIN GENE DISRUPTION RESULTS IN PERINATAL LETHALITY BECAUSE OF SEVERE MUSCLE DEFECT
SO NATURE
LA English
DT Article
ID myod; fibroblasts; expression; myoblasts; inactivation; somites; family; myf-5; mrf4
AB MYOGENIN is a member of the basic helix-loop-helix (bHLH) gene family and converts multipotential mesodermal cells to myoblasts1-4. The four members of the myoD family show unique spatio-temporal expression patterns5 and therefore may have different functions during myogenesis. Here we inactivate the myogenin gene in order to understand its role in myogenesis. Homozygous mutations are lethal perinatally owing to the resulting major defects in skeletal muscle. The extent of disorganization of muscle tissue differs in three regions. In the latero-ventral body wall, most cells, including myogenic cells, disappear and there is rapid accretion of fluid. In the limbs, cells of the myogenic lineage exist, but they are severely disrupted, and some of them are mono-nucleate with properties of myoblasts. In contrast, there are many axial, intercostal and back muscle fibres to be seen, although fibres are mainly disorganized and Z-lines are not present in most myofibrils. These findings are evidence that myogenin is crucial for muscle development in utero and demonstrate that other members of the myogenic gene family cannot compensate for the defect.
C1 NATL INST NEUROSCI,DEPT ANIM MODEL HUMAN DIS,KODAIRA,TOKYO 187,JAPAN.
   NATL INST NEUROSCI,DEPT ULTRASTRUCT RES,KODAIRA,TOKYO 157,JAPAN.
   JICHI MED SCH,DEPT NEUROL,MINAMI KAWACHI,TOCHIGI 32904,JAPAN.
C3 National Center for Neurology & Psychiatry - Japan; National Center for Neurology & Psychiatry - Japan; Jichi Medical University
RP NABESHIMA, Y (corresponding author), NATL INST NEUROSCI,DEPT MOLEC GENET,NCNP 4-1-1,OGAWAHIGASHI,KODAIRA,TOKYO 187,JAPAN.
NR 26
TC 790
Z9 956
U1 0
U2 37
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 532
EP 535
DI 10.1038/364532a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700056
PM 8393146
DA 2026-03-10
ER

PT J
AU TORRES, BA
   GRIGGS, ND
   JOHNSON, HM
AF TORRES, BA
   GRIGGS, ND
   JOHNSON, HM
TI BACTERIAL AND RETROVIRAL SUPERANTIGENS SHARE A COMMON BINDING REGION ON CLASS-II MHC ANTIGENS
SO NATURE
LA English
DT Article
ID staphylococcal enterotoxin-a; mammary-tumor virus; hla-dr; molecules; peptides; surface; cells
AB STAPHYLOCOCCAL enterotoxin A (SEA), one of the most potent T-cell mitogens known, has been classified as a bacterial superantigen on the basis of ability to stimulate Vbeta-specific T-cell subsets1. SEA interacts with class II major histocompatibility complex (MHC) antigens on antigen-presenting cells and the T-cell antigen receptor (TCR) on T cells2-4, resulting in a ternary complex of MHC-SEA-TCR. Mls antigens are known to be products of mouse mammary tumour virus (MMTV)5,6, and it has been reported that two exogenous strains of MMTV encode retroviral superantigens in the open reading frames of the 3' long terminal repeat of the viral genome7,8; however, no binding of the putative MMTV superantigen to either MHC antigens or TCR has been demonstrated. Here we use synthetic peptides to identify a site on the MMTV-1 superantigen that binds to class II MHC antigens. The site is encompassed by amino-acid residues 76-119 of the MMTV-1 superantigen. Direct binding and competition experiments show that the MMTV superantigen and SEA bind to at least one common region on class II MHC antigens.
RP TORRES, BA (corresponding author), UNIV FLORIDA,DEPT MICROBIOL & CELL SCI,GAINESVILLE,FL 32611, USA.
NR 22
TC 32
Z9 33
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 152
EP 154
DI 10.1038/364152a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700051
PM 8391645
DA 2026-03-10
ER

PT J
AU EMBRETSON, J
   ZUPANCIC, M
   RIBAS, JL
   BURKE, A
   RACZ, P
   TENNERRACZ, K
   HAASE, AT
AF EMBRETSON, J
   ZUPANCIC, M
   RIBAS, JL
   BURKE, A
   RACZ, P
   TENNERRACZ, K
   HAASE, AT
TI MASSIVE COVERT INFECTION OF HELPER T-LYMPHOCYTES AND MACROPHAGES BY HIV DURING THE INCUBATION PERIOD OF AIDS
SO NATURE
LA English
DT Article
ID human-immunodeficiency-virus; lymph-nodes; insitu hybridization; visna virus; lymphadenopathy; amplification; cells; dna; pathogenesis; mechanisms
AB ANIMAL and human lentiviruses elude host defences by establishing covert infections and eventually cause disease through cumulative losses of cells that die with activation of viral gene expression1-5. We used polymerase chain reaction in situ double-label methods6,7 to determine how many CD4+ lymphocytes are latently infected by human immunodeficiency virus (HIV) in patient lymph nodes and whether the pool of infected cells is large enough to account for immune depletion through continual activation of viral gene expression and attrition of cells responding to antigens. We discovered an extraordinarily large number of latently infected CD4+ lymphocytes and macrophages throughout the lymphoid system from early to late stages of infection, and confirmed8-14 the extracellular association of HIV with follicular dendritic cells. Follicular dendritic cells may transmit infection to cells as they migrate through lymphoid follicles. Latently infected lymphocytes and macrophages constitute an intracellular reservoir large enough ultimately to contribute to much of the immune depletion in AIDS, and represent a difficult problem that must be resolved in developing effective treatments and protective vaccine.
C1 UNIV MINNESOTA,DEPT MICROBIOL,420 DELAWARE ST SE,MINNEAPOLIS,MN 55455.
   HENRY M JACKSON FDN,ROCKVILLE,MD 20850.
   US DEPT DEF,ARMED FORCES INST PATHOL,DEPT CARDIOVASC PATHOL,WASHINGTON,DC 20306.
   BERNHARD NOCHT INST TROP MED,W-2000 HAMBURG 36,GERMANY.
C3 University of Minnesota System; University of Minnesota Twin Cities; Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc; United States Department of Defense; Leibniz Association; Bernhard Nocht Institut fur Tropenmedizin
NR 21
TC 1343
Z9 1449
U1 0
U2 44
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 359
EP 362
DI 10.1038/362359a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600066
PM 8096068
DA 2026-03-10
ER

PT J
AU SMITH, TM
   SHUGART, HH
AF SMITH, TM
   SHUGART, HH
TI THE TRANSIENT-RESPONSE OF TERRESTRIAL CARBON STORAGE TO A PERTURBED CLIMATE
SO NATURE
LA English
DT Article
ID simulation-model; cycle; stand
AB MODEL simulations suggest that at equilibrium, global warming driven by higher atmospheric concentrations of greenhouse gases will lead to increased terrestrial carbon storage1,2, implying a negative feedback between the global vegetation/soil system and the atmospheric CO2 Concentration. But changes in vegetation and soil type that result in a net release of CO2 to the atmosphere (such as those caused by wildfires) could be more rapid than changes that result in a net increase in terrestrial carbon storage (such as species immigration and soil formation), so that in its transient response to climate change, the terrestrial vegetation/soil system could be a net source of carbon to the atmosphere. Here we use two general circulation models3,4 to estimate the transient response of the terrestrial surface to a step doubling of atmospheric CO2. We find that vegetation and soil changes could prove to be a significant source of CO2 in the first 50-100 years following a climate warming, increasing the atmospheric CO2 concentration by up to a third of the present level.
RP SMITH, TM (corresponding author), UNIV VIRGINIA, DEPT ENVIRONM SCI, CHARLOTTESVILLE, VA 22903 USA.
NR 21
TC 164
Z9 184
U1 0
U2 27
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 523
EP 526
DI 10.1038/361523a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400055
DA 2026-03-10
ER

PT J
AU FERGUSONSMITH, AC
   SASAKI, H
   CATTANACH, BM
   SURANI, MA
AF FERGUSONSMITH, AC
   SASAKI, H
   CATTANACH, BM
   SURANI, MA
TI PARENTAL-ORIGIN-SPECIFIC EPIGENETIC MODIFICATION OF THE MOUSE H19 GENE
SO NATURE
LA English
DT Article
ID dna methylation; x-chromosome; transcription; binding; expression; islands; genm; protein; mice; cpgs
AB THE H19 gene produces an abundant developmentally regulated transcript of unknown function in normal embryos1. In the mouse it lies on chromosome 7 and is subject to transcriptional regulation by parental imprinting, which results in the maternally inherited gene being expressed and the paternally inherited gene being repressed2. Embryos carrying maternal duplication/paternal deficiency for distal chromosome 7 (MatDi7)3 therefore express a double dose of H19. Here we examine the parental-origin-specific epigenetic modifications that may be involved in this regulation by comparing CpG methylation and nuclease sensitivity of chromatin in MatDi7 embryos with normal littermates. We show that specific sites in the CpG island promoter and 5' portion of the gene are methylated only on the paternal allele. Furthermore, active maternal alleles in chromatin of MatDi7 embryos are more sensitive and accessible to nucleases. Therefore hypermethylation and chromatin compaction in the region of the H19 promoter is associated with repression of the paternally inherited copy of the gene. Most, but not all, of these sites are unmethylated in sperm, with methylation of the paternal promoter occurring after fertilization. These results contrast with our findings for the closely linked and reciprocally imprinted gene encoding insulin-like growth factor II (ref. 4).
C1 UNIV CAMBRIDGE, PHYSIOL LAB, CAMBRIDGE, ENGLAND.
   MRC, RADIOBIOL UNIT, DIDCOT OX1 3RD, OXON, ENGLAND.
C3 University of Cambridge; MRC Harwell
RP FERGUSONSMITH, AC (corresponding author), WELLCOME CRC INST CANC & DEV BIOL, TENNIS COURT RD, CAMBRIDGE CB2 1QR, ENGLAND.
FU Wellcome Trust Funding Source: Medline
NR 32
TC 392
Z9 436
U1 0
U2 23
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 751
EP 755
DI 10.1038/362751a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000057
PM 8469285
DA 2026-03-10
ER

PT J
AU LIPTON, SA
   CHOI, YB
   PAN, ZH
   LEI, SZZ
   CHEN, HSV
   SUCHER, NJ
   LOSCALZO, J
   SINGEL, DJ
   STAMLER, JS
AF LIPTON, SA
   CHOI, YB
   PAN, ZH
   LEI, SZZ
   CHEN, HSV
   SUCHER, NJ
   LOSCALZO, J
   SINGEL, DJ
   STAMLER, JS
TI A REDOX-BASED MECHANISM FOR THE NEUROPROTECTIVE AND NEURODESTRUCTIVE EFFECTS OF NITRIC-OXIDE AND RELATED NITROSO-COMPOUNDS
SO NATURE
LA English
DT Article
ID receptor-channel complex; nmda receptor; glutamate neurotoxicity; superoxide-dismutase; modulatory site; neuronal injury; nervous-system; peroxynitrite; inhibition; oxidation
AB CONGENERS of nitrogen monoxide (NO) are neuroprotective and neurodestructive1-7. To address this apparent paradox, we considered the effects on neurons of compounds characterized by alternative redox states of NO: nitric oxide (NO.) and nitrosonium ion (NO+)8. Nitric oxide, generated from NO. donors or synthesized endogenously after NMDA (N-methyl-D-aspartate) receptor activation, can lead to neurotoxicity3,4. Here, we report that NO.-mediated neurotoxicity is engendered, at least in part, by reaction with superoxide anion (O2.-), apparently leading to formation of peroxynitrite (ONOO-), and not by NO. alone. In contrast, the neuroprotective effects of NO result from downregulation of NMDA-receptor activity by reaction with thiol group(s) of the receptor's redox modulatory site1. This reaction is not mediated by NO. itself, but occurs under conditions supporting S-nitrosylation of NMDA receptor thiol (reaction or transfer of NO+). Moreover, the redox versatility of NO allows for its interconversion from neuroprotective to neurotoxic species by a change in the ambient redox milieu. The details of this complex redox chemistry of NO may provide a mechanism for harnessing neuroprotective effects and avoiding neurotoxicity in the central nervous system.
C1 HARVARD UNIV,SCH MED,PROGRAM NEUROSCI,BOSTON,MA 02115.
   CHILDRENS HOSP MED CTR,DEPT NEUROL,BOSTON,MA 02115.
   BETH ISRAEL HOSP,DEPT NEUROL,BOSTON,MA 02215.
   MASSACHUSETTS GEN HOSP,DEPT NEUROL,BOSTON,MA 02114.
   HARVARD UNIV,BRIGHAM & WOMENS HOSP,SCH MED,DEPT MED,DIV NEUROL,BOSTON,MA 02115.
   HARVARD UNIV,BRIGHAM & WOMENS HOSP,SCH MED,DEPT MED,DIV CARDIOVASC,BOSTON,MA 02115.
   HARVARD UNIV,BRIGHAM & WOMENS HOSP,SCH MED,DEPT MED,DIV RESP,BOSTON,MA 02115.
   HARVARD UNIV,SCH MED,BROCKTON W ROXBURY VET ADM MED CTR,CARDIOL SECT,BOSTON,MA 02115.
   HARVARD UNIV,DEPT CHEM,CAMBRIDGE,MA 02138.
C3 Harvard University; Harvard Medical School; Harvard University; Harvard University Medical Affiliates; Boston Children's Hospital; Harvard University; Harvard University Medical Affiliates; Beth Israel Deaconess Medical Center; Harvard University; Harvard University Medical Affiliates; Massachusetts General Hospital; Harvard University; Harvard University Medical Affiliates; Brigham & Women's Hospital; Harvard Medical School; Harvard University; Harvard Medical School; Harvard University Medical Affiliates; Brigham & Women's Hospital; Harvard University; Harvard Medical School; Harvard University Medical Affiliates; Brigham & Women's Hospital; Harvard University; Harvard Medical School; Harvard University
RP LIPTON, SA (corresponding author), HARVARD UNIV,CHILDRENS HOSP,SCH MED,CELLULAR & MOLEC NEUROSCI LAB,300 LONGWOOD AVE,ENDERS BLDG,BOSTON,MA 02115, USA.
NR 34
TC 2309
Z9 2474
U1 1
U2 106
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 626
EP 632
DI 10.1038/364626a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100053
PM 8394509
DA 2026-03-10
ER

PT J
AU WAHLESTEDT, C
   GOLANOV, E
   YAMAMOTO, S
   YEE, F
   ERICSON, H
   YOO, H
   INTURRISI, CE
   REIS, DJ
AF WAHLESTEDT, C
   GOLANOV, E
   YAMAMOTO, S
   YEE, F
   ERICSON, H
   YOO, H
   INTURRISI, CE
   REIS, DJ
TI ANTISENSE OLIGODEOXYNUCLEOTIDES TO NMDA-R1 RECEPTOR-CHANNEL PROTECT CORTICAL-NEURONS FROM EXCITOTOXICITY AND REDUCE FOCAL ISCHEMIC INFARCTIONS
SO NATURE
LA English
DT Article
ID ischemic brain-damage; glutamate neurotoxicity; antagonist; rat; affinity; binding
AB THE excitatory amino acid, L-glutamate, acting through its N-methyl-D-aspartate (NMDA) receptor, may contribute to neuronal death following cerebral vascular occlusion1-3. In support of this hypothesis, NMDA receptor antagonists reduce the volume of infarction produced by occlusion of the middle cerebral artery in vivo4,5 and attenuate Ca2+ influx and neuronal death elicited by L-glutamate or NMDA in vitro3,6. A complementary DNA coding for a major component of the NMDA receptor channel complex, a single protein of M(r) 105.5K (NMDA-R1), has been isolated from rat brain7. Here we demonstrate that inhibition of the synthesis of NMDA-R1 by treatment with antisense oligodeoxynucleotides selectively reduces the expression of NMDA receptors, prevents the neurotoxicity elicited by NMDA in vitro and reduces the volume of the focal ischaemic infarction produced by occlusion of the middle cerebral artery in the rat.
C1 CORNELL UNIV,MED CTR,COLL MED,DEPT PHARMACOL,NEW YORK,NY 10021.
C3 Cornell University
RP WAHLESTEDT, C (corresponding author), CORNELL UNIV,MED CTR,COLL MED,DEPT NEUROL & NEUROSURG,DIV NEUROBIOL,411 E 69TH ST,NEW YORK,NY 10021, USA.
NR 21
TC 378
Z9 419
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 260
EP 263
DI 10.1038/363260a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600052
PM 8487863
DA 2026-03-10
ER

PT J
AU ROSEN, DR
   SIDDIQUE, T
   PATTERSON, D
   FIGLEWICZ, DA
   SAPP, P
   HENTATI, A
   DONALDSON, D
   GOTO, J
   OREGAN, JP
   DENG, HX
   RAHMANI, Z
   KRIZUS, A
   MCKENNAYASEK, D
   CAYABYAB, A
   GASTON, SM
   BERGER, R
   TANZI, RE
   HALPERIN, JJ
   HERZFELDT, B
   VANDENBERGH, R
   HUNG, WY
   BIRD, T
   DENG, G
   MULDER, DW
   SMYTH, C
   LAING, NG
   SORIANO, E
   PERICAKVANCE, MA
   HAINES, J
   ROULEAU, GA
   GUSELLA, JS
   HORVITZ, HR
   BROWN, RH
AF ROSEN, DR
   SIDDIQUE, T
   PATTERSON, D
   FIGLEWICZ, DA
   SAPP, P
   HENTATI, A
   DONALDSON, D
   GOTO, J
   OREGAN, JP
   DENG, HX
   RAHMANI, Z
   KRIZUS, A
   MCKENNAYASEK, D
   CAYABYAB, A
   GASTON, SM
   BERGER, R
   TANZI, RE
   HALPERIN, JJ
   HERZFELDT, B
   VANDENBERGH, R
   HUNG, WY
   BIRD, T
   DENG, G
   MULDER, DW
   SMYTH, C
   LAING, NG
   SORIANO, E
   PERICAKVANCE, MA
   HAINES, J
   ROULEAU, GA
   GUSELLA, JS
   HORVITZ, HR
   BROWN, RH
TI MUTATIONS IN CU/ZN SUPEROXIDE-DISMUTASE GENE ARE ASSOCIATED WITH FAMILIAL AMYOTROPHIC-LATERAL-SCLEROSIS
SO NATURE
LA English
DT Article
ID motor neuron disease; downs-syndrome; saccharomyces-cerevisiae; neuromuscular-junction; escherichia-coli; linkage analysis; transgenic mice; monosomy-21; resolution; pathology
AB AMYOTROPHIC lateral sclerosis (ALS) is a degenerative disorder of motor neurons in the cortex, brainstem and spinal cord1,2. Its cause is unknown and it is uniformly fatal, typically within five years3. About 10% of cases are inherited as an autosomal dominant trait, with high penetrance after the sixth decade4,5. In most instances, sporadic and autosomal dominant familial ALS (FALS) are clinically similar4,6,7. We have previously shown that in some but not all FALS pedigrees the disease is linked to a genetic defect on chromosome 21q (refs 8, 9). Here we report tight genetic linkage between FALS and a gene that encodes a cytosolic, Cu/Zn-binding superoxide dismutase (SOD1), a homodimeric metalloenzyme that catalyzes the dismutation of the toxic superoxide anion O2.- to O2 and H2O2 (ref. 10). Given this linkage and the potential role of free radical toxicity in other neurodenegerative disorders11, we investigated SOD1 as a candidate gene in FALS. We identified 11 different SOD1 missense mutations in 13 different FALS families.
C1 MASSACHUSETTS GEN HOSP, DAY NEUROMUSCULAR RES LAB,ROOM 6627,MGH-E, BLDG 149,13TH ST, BOSTON, MA 02129 USA.
   NORTHWESTERN UNIV, SCH MED, DEPT NEUROL, CHICAGO, IL 60611 USA.
   ELEANOR ROOSEVELT INST CANC RES, DENVER, CO 80206 USA.
   UNIV COLORADO, HLTH SCI CTR, DENVER, CO 80206 USA.
   MCGILL UNIV, CTR RES NEUROSCI, MONTREAL H3A 2T5, QUEBEC, CANADA.
   MONTREAL GEN HOSP, RES INST, MONTREAL H3G 1A4, QUEBEC, CANADA.
   MIT, DEPT BIOL, HOWARD HUGHES MED INST, CAMBRIDGE, MA 02139 USA.
   MASSACHUSETTS GEN HOSP, CTR NEUROSCI, GENET & AGING LAB, BOSTON, MA 02129 USA.
   NORTHSHORE UNIV HOSP, DEPT NEUROL, MANHASSET, NY 11030 USA.
   UNIV ZIEKENHUIZEN, DEPT NEUROL, B-3000 LOUVAIN, BELGIUM.
   UNIV WASHINGTON, SCH MED, DEPT NEUROL, SEATTLE, WA 98195 USA.
   MAYO CLIN & MAYO FDN, DEPT NEUROL, ROCHESTER, MN 55905 USA.
   AUSTRALIAN NEUROMUSCULAR RES INST, NEDLANDS, WA, AUSTRALIA.
   DUKE UNIV, MED CTR, DEPT MED NEUROL, DURHAM, NC 27710 USA.
   MASSACHUSETTS GEN HOSP, CTR NEUROSCI, MOLEC NEUROGENET LAB, BOSTON, MA 02129 USA.
C3 Harvard University; Harvard University Medical Affiliates; Massachusetts General Hospital; Northwestern University; University of Colorado System; University of Colorado Denver; University of Colorado Anschutz Medical Campus; McGill University; McGill University; Howard Hughes Medical Institute; Massachusetts Institute of Technology (MIT); Harvard University; Harvard University Medical Affiliates; Massachusetts General Hospital; University of Washington; University of Washington Seattle; Mayo Clinic; University of Western Australia; Duke University; Harvard University; Harvard University Medical Affiliates; Massachusetts General Hospital
NR 47
TC 5671
Z9 6144
U1 17
U2 774
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 59
EP 62
DI 10.1038/362059a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600059
PM 8446170
DA 2026-03-10
ER

PT J
AU RIEBESELL, U
   WOLFGLADROW, DA
   SMETACEK, V
AF RIEBESELL, U
   WOLFGLADROW, DA
   SMETACEK, V
TI CARBON-DIOXIDE LIMITATION OF MARINE-PHYTOPLANKTON GROWTH-RATES
SO NATURE
LA English
DT Article
ID ice core; co2; sea; temperature
AB THE supply of dissolved inorganic carbon (DIC) is not considered to limit oceanic primary productivity1, as its concentration in sea water exceeds that of other plant macronutrients such as nitrate and phosphate by two and three orders of magnitude, respectively. But the bulk of oceanic new production2 and a major fraction of vertical carbon flux is mediated by a few diatom genera whose ability to use DIC components other than CO2, which comprises < 1% of total DIC3, is unknown 4. Here we show that under optimal light and nutrient conditions, diatom growth rate can in fact be limited by the supply of CO2. The doubling in surface water PCO2 levels since the last glaciation from 180 to 355 p.p.m.5,6  could therefore have stimulated marine productivity, thereby increasing oceanic carbon sequestration by the biological pump.
C1 ALFRED WEGENER INST POLAR & MARINE RES,W-2850 BREMERHAVEN,GERMANY.
C3 Helmholtz Association; Alfred Wegener Institute, Helmholtz Centre for Polar & Marine Research
NR 25
TC 499
Z9 565
U1 3
U2 161
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 249
EP 251
DI 10.1038/361249a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400055
DA 2026-03-10
ER

PT J
AU GALYOV, EE
   HAKANSSON, S
   FORSBERG, A
   WOLFWATZ, H
AF GALYOV, EE
   HAKANSSON, S
   FORSBERG, A
   WOLFWATZ, H
TI A SECRETED PROTEIN-KINASE OF YERSINIA-PSEUDOTUBERCULOSIS IS AN INDISPENSABLE VIRULENCE DETERMINANT
SO NATURE
LA English
DT Article
ID outer-membrane proteins; yop2b protein; calcium; transcription; temperature; expression; genes; level
AB PHOSPHORYLATION of proteins catalysed by protein kinases is associated with central functions in growth and proliferation of the eukaryotic cell, and kinases are particularly important in the signal transduction pathways1,2. Enterobacterial protein kinases are structurally and functionally different from eukaryotic protein kinases3,4, and no prokaryotic kinase has so far been described implicating a direct role for this activity in virulence. Virulent Yersinia possess a common virulence plasmid that encodes a number of secreted proteins (Yops)5-7, of which YopH has protein-tyrosine phosphatase activity with a key function in the block of phagocytosis by the pathogen8-10. Here we report that the virulence plasmid of Yersinia pseudotuberculosis encodes a secreted protein kinase (YpkA) with extensive homology to eukaryotic Ser/Thr protein kinases3,11. Specific mutants of ypkA resulted in avirulent strains. Thus, YpkA is, to our knowledge, the first reported prokaryotic secreted protein kinase involved in pathogenicity, presumably by interfering with the signal transduction pathways of the target cell.
C1 UMEA UNIV,DEPT CELL & MOLEC BIOL,S-90187 UMEA,SWEDEN.
   NATL DEF RES ESTAB,DEPT MICROBIOL,S-90182 UMEA,SWEDEN.
C3 Umea University
NR 20
TC 273
Z9 311
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 730
EP 732
DI 10.1038/361730a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900058
PM 8441468
DA 2026-03-10
ER

PT J
AU JORDAN, G
   MOLLON, JD
AF JORDAN, G
   MOLLON, JD
TI THE NAGEL ANOMALOSCOPE AND SEASONAL-VARIATION OF COLOR-VISION
SO NATURE
LA English
DT Article
AB IN 1948 the German physicist, Manfred Richter, reported that colour vision has a seasonal variation1,2. For four colour-normal subjects, he found a sinusoidal variation in the proportion of red and green required to match a monochromatic yellow, the equation known as the 'Rayleigh match'3. In summer, subjects required more red in their mixture. The measurements were made with the Nagel anomaloscope, an instrument introduced in 1907(4,5) and which today, essentially unchanged, remains the definitive clinical instrument for classifying the many phenotypic variations in colour vision. The variation that Richter recorded in the red-green ratio was large (three Nagel units), and it now takes on fresh interest because it is comparable in size to the difference in Nagel settings later reported between normal observers of different genetic type6,7. We have been able to replicate Richter's result, but report here that it is almost certainly instrumental: the Nagel anomaloscope proves to be very sensitive to ambient temperature.
RP JORDAN, G (corresponding author), UNIV CAMBRIDGE, DEPT EXPTL PSYCHOL, DOWNING ST, CAMBRIDGE CB2 3EB, ENGLAND.
NR 16
TC 18
Z9 20
U1 0
U2 4
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 546
EP 549
DI 10.1038/363546a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900051
PM 8505982
DA 2026-03-10
ER

PT J
AU FISHER, AJ
   JOHNSON, JE
AF FISHER, AJ
   JOHNSON, JE
TI ORDERED DUPLEX RNA CONTROLS CAPSID ARCHITECTURE IN AN ICOSAHEDRAL ANIMAL VIRUS
SO NATURE
LA English
DT Article
ID bushy stunt virus; 3.0-a resolution
AB SMALL spherical viruses are among the simplest replicating systems in biology, yet the factors affecting their assembly, stability and disassembly are still poorly understood. A molecular switch is required for the assembly of icosahedral virus particles containing more than 60 identical subunits because strict symmetry cannot be maintained in subunit packing1. All previously reported viruses with this type of structure use a portion of the capsid protein to regulate interactions between chemically equivalent but structurally distinct interfaces2-4. We have investigated the T = 3 quasi-equivalent5 nodaviruses, which are small non-enveloped viruses with a single-stranded RNA genome that infect insects6, mice7 and fish8. They undergo a well-characterized series of steps in assembly and maturation9,10, which in some respects are similar to the picornaviruses11, despite their different capsid architecture. Here we report the X-ray structure of Flock House virus at 3.0 angstrom resolution, which reveals an ordered RNA duplex of 20 nucleotides and a protein segment that control the subunit interactions in this animal virus. The RNA interacts with a helical protein domain of the subunit that lies inside the capsid shell. One of the helices that binds the RNA is part of a 44-amino-acid polypeptide which is autocatalytically cleaved from the initial subunit translation product after virion assembly. The structure indicates that RNA associated with the cleaved polypeptide may be important in the infection process.
C1 UNIV WISCONSIN,DEPT BIOL SCI,MADISON,WI 53706.
C3 University of Wisconsin System; University of Wisconsin Madison
NR 24
TC 237
Z9 263
U1 0
U2 13
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 176
EP 179
DI 10.1038/361176a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600067
PM 8421524
DA 2026-03-10
ER

PT J
AU AARTS, MGM
   DIRKSE, WG
   STIEKEMA, WJ
   PEREIRA, A
AF AARTS, MGM
   DIRKSE, WG
   STIEKEMA, WJ
   PEREIRA, A
TI TRANSPOSON TAGGING OF A MALE-STERILITY GENE IN ARABIDOPSIS
SO NATURE
LA English
DT Article
ID transgenic tobacco; spm element; maize; cells
AB TRANSFORMATION of the well-studied maize transposable elements into other plant species1 should enable transposon tagging methodology2 to be used for the isolation of interesting genes in the heterologous host. Here we describe the isolation of a transposon-tagged male sterile mutant in Arabidopsis thaliana using the maize Enhancer-Inhibitor3,4 transposable element system introduced into Arabidopsis. The mutant lacks pollen, preventing normal self-fertilization, a characteristic important for production of hybrid seed in many crop plants. We have identified an Enhancer-transposase-mediated Inhibitor element insertion responsible for the male sterile phenotype, and isolated the corresponding gene named MALE STERILITY 2. Critical evidence that the Inhibitor-element-containing gene is involved in the male sterile phenotype is provided by the DNA sequences of new excision-derived alleles from independent stable fertile and male sterile progeny of the original mutant.
C1 DLO,CTR PLANT BREEDING & REPROD RES,DEPT MOLEC BIOL,POB 16,6700 AA WAGENINGEN,NETHERLANDS.
NR 22
TC 162
Z9 216
U1 1
U2 18
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 715
EP 717
DI 10.1038/363715a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900054
PM 8390620
DA 2026-03-10
ER

PT J
AU KORTHAUER, U
   GRAF, D
   MAGES, HW
   BRIERE, F
   PADAYACHEE, M
   MALCOLM, S
   UGAZIO, AG
   NOTARANGELO, LD
   LEVINSKY, RJ
   KROCZEK, RA
AF KORTHAUER, U
   GRAF, D
   MAGES, HW
   BRIERE, F
   PADAYACHEE, M
   MALCOLM, S
   UGAZIO, AG
   NOTARANGELO, LD
   LEVINSKY, RJ
   KROCZEK, RA
TI DEFECTIVE EXPRESSION OF T-CELL CD40 LIGAND CAUSES X-LINKED IMMUNODEFICIENCY WITH HYPER-IGM
SO NATURE
LA English
DT Article
ID human lymphocytes-b; hyperimmunoglobulinemia-m; antigen; proliferation; form
AB X CHROMOSOME-LINKED immunodeficiency with hyper-IgM (HIGM1, MIM number 308230) is a rare disorder characterized by recurrent bacterial infections, very low or absent IgG, IgA and IgE, and normal to increased IgM and IgD serum levels1-3. HIGM1 has been suggested to result from ineffective T-cell help for B cells4. We and others5-8 have identified a novel, TNF-related activation protein (TRAP) that is exclusively expressed on the surface of stimulated T cells6,8. TRAP, a type II transmembrane protein of M(r) 33,000, is the physiological ligand for CD40 (refs 5-8). Crosslinking of CD40 on B cells induces, in the presence of lymphokines, immunoglobulin class switching from IgM to IgG, IgA or IgE5,9-11. Mapping of the TRAP gene to the X-chromosomal location q26.3-q27.1 (ref. 6) suggested a causal relationship to HIGM1, which had previously been assigned to Xq26 (refs 12-14). Here we present evidence that point mutations in the TRAP gene give rise to nonfunctional or defective expression of TRAP on the surface of T cells in patients with HIGM1. The resultant failure of TRAP to interact with CD40 on functionally intact B cells is responsible for the observed immunoglobulin isotype defect in HIGM1.
C1 UNIV ERLANGEN NURNBERG, INST KLIN IMMUNOL, ARBEITSGRP IMMUNOL, MAX PLANCK GESELLSCH, W-8520 ERLANGEN, GERMANY.
   SCHERING PLOUGH CORP, IMMUNOL RES LAB, F-69571 DARDILLY, FRANCE.
   INST CHILD HLTH, LONDON WC1N 1EH, ENGLAND.
   UNIV BRESCIA, I-25123 BRESCIA, ITALY.
C3 University of Erlangen Nuremberg; Max Planck Society; Merck & Company; Schering Plough Corporation; University of London; University College London; University of Brescia
NR 18
TC 682
Z9 738
U1 0
U2 4
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 539
EP 541
DI 10.1038/361539a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400061
PM 7679206
DA 2026-03-10
ER

PT J
AU HOSOI, J
   MURPHY, GF
   EGAN, CL
   LERNER, EA
   GRABBE, S
   ASAHINA, A
   GRANSTEIN, RD
AF HOSOI, J
   MURPHY, GF
   EGAN, CL
   LERNER, EA
   GRABBE, S
   ASAHINA, A
   GRANSTEIN, RD
TI REGULATION OF LANGERHANS CELL-FUNCTION BY NERVES CONTAINING CALCITONIN GENE-RELATED PEPTIDE
SO NATURE
LA English
DT Article
ID human-skin; fibers associate; immune-system; neuropeptides; innervation; rats; cgrp; immunoreactivity; compartments; lymphocytes
AB SEVERAL observations suggest interactions between the immune and nervous systems1,2. Psoriasis and atopic dermatitis may worsen with anxiety and have been associated with anomalous neuropeptide regulation2. Neurotransmitters affect lymphocyte function1-4 and lymphoid organs are innervated5-9. Calcitonin gene-related peptide (CGRP) is a neuropeptide and vasodilator10 that modulates some macrophage functions, including antigen presentation in vitro11. CGRP is associated with Langerhans cells (LC) in oesophageal mucosa, particularly during inflammation12, is present in epidermal nerves and is associated with Merkel cells10,13-15. We examined the ability of CGRP to modulate LC antigen-presenting function16 and asked if CGRP-containing nerve impinge on LC. We report here that CGRP-containing nerve fibers are intimately associated with LC in human epidermis and CGRP is found at the surface of some LC. In three functional assay, CGRP inhibited LC antigen presentation. These findings indicate that CGRP may have immunomodulatory effects in vivo and suggest a locus of interaction between the nervous system and immunological function.
C1 MASSACHUSETTS GEN HOSP E, MGH HARVARD CUTANEOUS BIOL RES CTR, BLDG 149, 13TH ST, BOSTON, MA 02129 USA.
   UNIV PENN, DEPT DERMATOL, PHILADELPHIA, PA 19104 USA.
C3 University of Pennsylvania
NR 28
TC 529
Z9 572
U1 2
U2 20
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 159
EP 163
DI 10.1038/363159a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100047
PM 8483499
DA 2026-03-10
ER

PT J
AU BIGNAMI, GF
   CARAVEO, PA
   MEREGHETTI, S
AF BIGNAMI, GF
   CARAVEO, PA
   MEREGHETTI, S
TI THE PROPER MOTION OF GEMINGAS OPTICAL COUNTERPART
SO NATURE
LA English
DT Article
ID gamma-ray sources; 1e 0630+178; pulsars
AB THE strong gamma-ray source Geminga was first observed by the satellite SAS-2 1,2 and later seen by the COS-B satellite3,4. An association with the peculiar X-ray source 1E0630 + 178 was proposed5, suggesting that Geminga is a nearby neutron star (approximately 100 pc from Earth) which is not visible as a radio pulsar. Searches for its optical counterpart yielded as the best candidate a very faint (m(v) = 25.5) object, G'', which was proposed on the basis of its colours6-8. The association of Geminga with 1E0630 + 178 was confirmed recently by the discovery of a 237-ms periodicity in the soft X-ray emission9 from the latter; such oscillations were recognized immediately afterwards in data10 from the Gamma Ray Observatory, and in reanalysis of the COS-B11 and SAS-2 data12. As its timing and energy parameters indicated that Geminga is closer than 400 pc, Bignami and Caraveo suggested'' that the proper motion of the optical counterpart G'' might be measurable. Here we compare a 1992 optical image of G'' with previous data from 1984 and 1987, and find that the proper motion is 0.17 arcsec per year. This motion is consistent with the identification of G'' as a neutron star at a distance of about 100 pc, thus confirming it as the optical counter art of Geminga.
C1 UNIV CASSINO,DIPARTIMENTO INGN IND,I-03043 CASSINO,ITALY.
C3 University of Cassino
RP BIGNAMI, GF (corresponding author), CNR,IST FIS COSM,VIA BASSINI 15,I-20133 MILAN,ITALY.
NR 22
TC 72
Z9 74
U1 2
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 704
EP 706
DI 10.1038/361704a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900047
DA 2026-03-10
ER

PT J
AU HYDE, SC
   GILL, DR
   HIGGINS, CF
   TREZISE, AEO
   MACVINISH, LJ
   CUTHBERT, AW
   RATCLIFF, R
   EVANS, MJ
   COLLEDGE, WH
AF HYDE, SC
   GILL, DR
   HIGGINS, CF
   TREZISE, AEO
   MACVINISH, LJ
   CUTHBERT, AW
   RATCLIFF, R
   EVANS, MJ
   COLLEDGE, WH
TI CORRECTION OF THE ION-TRANSPORT DEFECT IN CYSTIC-FIBROSIS TRANSGENIC MICE BY GENE-THERAPY
SO NATURE
LA English
DT Article
ID transmembrane conductance regulator; respiratory epithelium; chloride channels; lung-disease; activation; expression; amiloride; cftr; membrane; calcium
AB CYSTIC fibrosis (CF) is a lethal inherited disorder affecting about 1 in 2,000 Caucasians. The major cause of morbidity is permanent lung damage resulting from ion transport abnormalities in airway epithelia that lead to mucus accumulation and bacterial colonization. CF is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene1 that encodes a cyclic-AMP-regulated chloride channel2,3.  Cyclic-AMP-regulated chloride conductances are altered in airway epithelia from CF patients4-6, suggesting that the functional expression of CFTR in the airways of CF patients may be a strategy for treatment. Transgenic mice7-9 With a disrupted cftr gene are appropriate for testing gene therapy protocols. Here we report the use of liposomes to deliver a CFTR expression plasmid to epithelia of the airway and to alveoli deep in the lung, leading to the correction of the ion conductance defects found in the trachea of transgenic (cf/cf) mice. These studies illustrate the feasibility of gene therapy for the pulmonary aspects of CF in humans.
C1 UNIV OXFORD,JOHN RADCLIFFE HOSP,INST MOLEC MED,IMPERIAL CANC RES FUND LABS,OXFORD OX3 9DU,ENGLAND.
   UNIV CAMBRIDGE,DEPT PHARMACOL,CAMBRIDGE CB2 1QJ,ENGLAND.
   UNIV CAMBRIDGE,DEPT GENET,CAMBRIDGE CB2 1QR,ENGLAND.
   UNIV CAMBRIDGE,WELLCOME CRC INST CANC & DEV BIOL,CAMBRIDGE CB2 1QR,ENGLAND.
C3 University of Oxford; Cancer Research UK; University of Cambridge; University of Cambridge; University of Cambridge
FU Wellcome Trust Funding Source: Medline
NR 33
TC 362
Z9 452
U1 1
U2 29
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 250
EP 255
DI 10.1038/362250a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600058
PM 7681548
DA 2026-03-10
ER

PT J
AU LOWE, SW
   SCHMITT, EM
   SMITH, SW
   OSBORNE, BA
   JACKS, T
AF LOWE, SW
   SCHMITT, EM
   SMITH, SW
   OSBORNE, BA
   JACKS, T
TI P53 IS REQUIRED FOR RADIATION-INDUCED APOPTOSIS IN MOUSE THYMOCYTES
SO NATURE
LA English
DT Article
ID wild-type; protein
AB THE p53 tumour suppressor gene is the most widely mutated gene in human tumorigenesis1,2. p53 encodes a transcriptional activator3-7 whose targets may include genes that regulate genomic stability8,9, the cellular response to DNA damage10,11, and cell-cycle progression12-13. Introduction of wild-type p53 into cell lines that have lost endogenous p53 function can cause growth arrest14-16 or induce a process of cell death known as apoptosis17,18. During normal development, self-reactive thymocytes undergo negative selection by apoptosis19, which can also be induced in immature thymocytes by other stimuli, including exposure to glucocorticoids15 and ionizing radiation16. Although normal negative selection involves signalling through the T-cell receptor14, the induction of apoptosis by other stimuli is poorly understood. We have investigated the requirement for p53 during apoptosis in mouse thymocytes. We report here that immature thymocytes lacking p53 die normally when exposed to compounds that may mimic T-cell receptor engagement and to glucocorticoids but are resistant to the lethal effects of ionizing radiation. These results demonstrate that p53 is required for radiation-induced cell death in the thymus but is not necessary for all forms of apoptosis.
C1 MIT,CTR CANC RES,DEPT BIOL,77 MASSACHUSETTS AVE,CAMBRIDGE,MA 02139.
   UNIV MASSACHUSETTS,DEPT VET & ANIM SCI,AMHERST,MA 01003.
   UNIV MASSACHUSETTS,PAIGE LAB 309,PROGRAM MOLEC & CELLULAR BIOL,AMHERST,MA 01003.
C3 Massachusetts Institute of Technology (MIT); University of Massachusetts System; University of Massachusetts Amherst; University of Massachusetts System; University of Massachusetts Amherst
NR 15
TC 2917
Z9 3118
U1 1
U2 86
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 847
EP 849
DI 10.1038/362847a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300059
PM 8479522
DA 2026-03-10
ER

PT J
AU CUBITT, R
   FORGAN, EM
   YANG, G
   LEE, SL
   PAUL, DM
   MOOK, HA
   YETHIRAJ, M
   KES, PH
   LI, TW
   MENOVSKY, AA
   TARNAWSKI, Z
   MORTENSEN, K
AF CUBITT, R
   FORGAN, EM
   YANG, G
   LEE, SL
   PAUL, DM
   MOOK, HA
   YETHIRAJ, M
   KES, PH
   LI, TW
   MENOVSKY, AA
   TARNAWSKI, Z
   MORTENSEN, K
TI DIRECT OBSERVATION OF MAGNETIC-FLUX LATTICE MELTING AND DECOMPOSITION IN THE HIGH-T(C) SUPERCONDUCTOR BI2.15SR1.95CACU2O8+X
SO NATURE
LA English
DT Article
ID single-crystal yba2cu3o7; high-tc superconductors; neutron-diffraction; thermal fluctuations; ii superconductors; phase-transitions; line lattice; penetration; creep; state
AB The flux line lattice inside a single crystal of Bi2.15Sr1.95CaCu2O8+x has been observed using small-angle neutron diffraction. The diffracted intensity goes rapidly to zero at a magnetic-field-dependent flux lattice melting temperature; this melting coincides with the appearance of finite resistance within the superconducting state. The flux lattice signal can also be made to disappear at low temperatures, by applying a sufficiently high field, probably because of the decomposition of flux lines into two-dimensional 'pancake' vortices.
C1 UNIV ZURICH,INST PHYS,CH-8057 ZURICH,SWITZERLAND.
   UNIV WARWICK,DEPT PHYS,COVENTRY CV4 7AL,W MIDLANDS,ENGLAND.
   OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831.
   LEIDEN UNIV,KAMERLINGH ONNES LAB,2312 AV LEIDEN,NETHERLANDS.
   UNIV AMSTERDAM,DEPT PHYS,1018 XE AMSTERDAM,NETHERLANDS.
   RISO NATL LAB,DEPT PHYS,DK-4000 ROSKILDE,DENMARK.
C3 University of Zurich; University of Warwick; United States Department of Energy (DOE); Oak Ridge National Laboratory; Leiden University - Excl LUMC; Leiden University; University of Amsterdam; Technical University of Denmark
RP CUBITT, R (corresponding author), UNIV BIRMINGHAM,SCH PHYS & SPACE RES,EDGBASTON,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND.
NR 23
TC 409
Z9 414
U1 0
U2 32
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 407
EP 411
DI 10.1038/365407a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300046
DA 2026-03-10
ER

PT J
AU CHRIVIA, JC
   KWOK, RPS
   LAMB, N
   HAGIWARA, M
   MONTMINY, MR
   GOODMAN, RH
AF CHRIVIA, JC
   KWOK, RPS
   LAMB, N
   HAGIWARA, M
   MONTMINY, MR
   GOODMAN, RH
TI PHOSPHORYLATED CREB BINDS SPECIFICALLY TO THE NUCLEAR-PROTEIN CBP
SO NATURE
LA English
DT Article
AB CYCLIC AMP-regulated gene expression frequently involves a DNA element known as the cAMP-regulated enhancer (CRE)1-4. Many transcription factors bind to this element, including the protein CREB5,6, which is activated as a result of phosphorylation by protein kinase A7. This modification stimulates interaction with one or more of the general transcription factors or, alternatively, allows recruitment of a co-activator. Here we report that CREB phosphorylated by protein kinase A binds specifically to a nuclear protein of M(r) 265K which we term CBP (for CREB-binding protein). Fusion of a heterologous DNA-binding domain to the amino terminus of CBP enables the chimaeric protein to function as a protein kinase A-regulated transcriptional activator. We propose that CBP may participate in cAMP-regulated gene expression by interacting with the activated phosphorylated form of CREB.
C1 CNRS,INSERM,CTR RECH BIOCHIM MACROMOLEC,F-34033 MONTPELLIER,FRANCE.
   OREGON HLTH SCI UNIV,VOLLUM INST,PORTLAND,OR 97201.
   SALK INST BIOL STUDIES,CLAYTON FDN LABS PEPTIDE BIOL,LA JOLLA,CA 92037.
C3 Centre National de la Recherche Scientifique (CNRS); Universite de Montpellier; Institut National de la Sante et de la Recherche Medicale (Inserm); Oregon Health & Science University; Salk Institute
NR 18
TC 1831
Z9 2088
U1 2
U2 86
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 855
EP 859
DI 10.1038/365855a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100056
PM 8413673
DA 2026-03-10
ER

PT J
AU TAZI, J
   KORNSTADT, U
   ROSSI, F
   JEANTEUR, P
   CATHALA, G
   BRUNEL, C
   LUHRMANN, R
AF TAZI, J
   KORNSTADT, U
   ROSSI, F
   JEANTEUR, P
   CATHALA, G
   BRUNEL, C
   LUHRMANN, R
TI THIOPHOSPHORYLATION OF U1-70K PROTEIN INHIBITS PREMESSENGER RNA SPLICING
SO NATURE
LA English
DT Article
ID small nuclear ribonucleoproteins; drosophila encodes; binding proteins; snrnp; spliceosome; polypeptide; regulators; yeast; site; u1
AB THE U1 small nuclear ribonucleoprotein (snRNP) particle is one of the Sm class of snRNPs essential for splicing of precursor messenger RNA1-5. Mammalian U1 snRNP contains a 165-nucleotide long RNA molecule and at least 11 proteins: the U1-specific 70K proteins A and C, and the common U snRNP proteins (B', B, D1, D2, D3, E, F and G). One of the functions of U1 snRNP is recognition of the 5' splice site, an event that requires both U1 RNA and U1 proteins6-10. The 70K protein is the only heavily phosphorylated U1 protein in the cell11,12. Isolated U1 snRNPs are associated with a kinase activity that selectively phosphorylates the 70K protein in vitro in a reaction requiring ATP. Here we investigate the role of phosphorylation of the 70K protein in the splicing of pre-mRNA. The 70K protein on U1 snRNPs was phosphorylated in vitro with either ATP, or with ATP-gammaS, which gave a thiophosphorylated product that was resistant to dephosphorylation by phosphatases. When HeLa nuclear splicing extracts that had been depleted of endogenous U1 snRNPs were complemented with U1 snRNPs possessing normal phosphorylated 70K protein, mature spliceosomes were generated and the splicing activity of the extracts was fully restored. By contrast, if thiophosphorylated U1 snRNPs were used instead, splicing was completely inhibited, although formation of the mature spliceosome was unaffected. Our data show that the state of phosphorylation of the U1-specific 70K protein is critical for its participation in a pre-catalytic step of the splicing reaction.
C1 UNIV MARBURG,INST MOLEK BIOL & TUMORFORSCH,W-3550 MARBURG,GERMANY.
C3 Philipps University Marburg
RP TAZI, J (corresponding author), UNIV MONTPELLIER 2,CNRS,UNITE GENET MOLEC 1191,F-34095 MONTPELLIER 5,FRANCE.
NR 29
TC 140
Z9 154
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 283
EP 286
DI 10.1038/363283a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600059
PM 8387646
DA 2026-03-10
ER

PT J
AU WING, SL
   HICKEY, LJ
   SWISHER, CC
AF WING, SL
   HICKEY, LJ
   SWISHER, CC
TI IMPLICATIONS OF AN EXCEPTIONAL FOSSIL FLORA FOR LATE CRETACEOUS VEGETATION
SO NATURE
LA English
DT Article
ID constants
AB THE rapid radiation of angiosperms during the Late Cretaceous has been thought to reflect their rise to vegetational dominance1-3. The number of species in a clade and its vegetational importance are not necessarily related, however. Quantitative studies of the recently discovered Big Cedar Ridge flora, found preserved in situ in a mid-Maastrichtian volcanic ash in central Wyoming, USA, reveal that dicotyledonous angiosperms accounted for 61% of the species but constituted just 12% of vegetational cover. Dicots, many of which appear to have been herbaceous, were abundant only in areas disturbed just before burial. By contrast, free-sporing plants were 19% of the species but 49% of cover. The only abundant and ubiquitous angiosperm was a single species of palm (about 25% of cover). A comparably low abundance of dicots was found in two other nearly contemporaneous floras buried by volcanic ash, whereas coeval floras from fluvial environments are dominated by dicots4. This shows that, even as late as the mid-Maastrichtian, in northern mid-latitudes there were areas away from streams that were not yet dominated by dicots. Despite vigorous taxonomic diversification during the previous 30 Myr3, dicots played a subordinate role in these areas of fern-dominated vegetation.
C1 YALE UNIV, DEPT GEOL & GEOPHYS, NEW HAVEN, CT 06520 USA.
   INST HUMAN ORIGINS, CTR GEOCHRONOL, BERKELEY, CA 94709 USA.
C3 Yale University
RP WING, SL (corresponding author), NATL MUSEUM NAT HIST, DEPT PALEOBIOL, WASHINGTON, DC 20560 USA.
NR 21
TC 119
Z9 142
U1 0
U2 20
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 342
EP 344
DI 10.1038/363342a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700050
DA 2026-03-10
ER

PT J
AU IVINSON, AJ
AF IVINSON, AJ
TI TAKING THE BULL BY THE HORNS
SO NATURE
LA English
DT Article
NR 6
TC 1
Z9 1
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 473
EP 473
DI 10.1038/363473a0
PG 1
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800066
DA 2026-03-10
ER

PT J
AU SMEYNE, RJ
   VENDRELL, M
   HAYWARD, M
   BAKER, SJ
   MIAO, GG
   SCHILLING, K
   ROBERTSON, LM
   CURRAN, T
   MORGAN, JI
AF SMEYNE, RJ
   VENDRELL, M
   HAYWARD, M
   BAKER, SJ
   MIAO, GG
   SCHILLING, K
   ROBERTSON, LM
   CURRAN, T
   MORGAN, JI
TI CONTINUOUS C-FOS EXPRESSION PRECEDES PROGRAMMED CELL-DEATH INVIVO
SO NATURE
LA English
DT Article
ID neurons; layer
AB THE development of a multicellular organism involves a delicate balance among the processes of proliferation, differentiation and death. Naturally occurring cell death aids tissue remodelling, eliminates supernumerary cell populations and provides structural elements such as hair and skin. In the nervous system, selective cell death contributes to the formation and organization of the spinal cord and sympathetic ganglia1, retina2 and corpus callosum3. But cell death also occurs in several neuropathological conditions, such as amyelotrophic lateral sclerosis4 and Alzheimer's disease5. Therefore an elucidation of the mechanisms responsible for cell death is critical for an appreciation of both normal development and neuropathological disorders. Using a fos-lacZ transgenic mouse6, we provide evidence showing that the continuous expression of Fos beginning hours or days before the morphological demise of the cell, appears to be a hallmark of terminal differentiation and a harbinger of death.
C1 ROCHE INST MOLEC BIOL,ROCHE RES CTR,DEPT NEUROSCI,NUTLEY,NJ 07110.
   ROCHE INST MOLEC BIOL,ROCHE RES CTR,DEPT MOLEC ONCOL & VIROL,NUTLEY,NJ 07110.
C3 Roche Holding; Roche Holding USA; Roche Holding; Roche Holding USA
NR 28
TC 790
Z9 835
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 166
EP 169
DI 10.1038/363166a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100049
PM 8483500
DA 2026-03-10
ER

PT J
AU HOLBROOK, WS
   KELEMEN, PB
AF HOLBROOK, WS
   KELEMEN, PB
TI LARGE IGNEOUS PROVINCE ON THE UNITED-STATES ATLANTIC MARGIN AND IMPLICATIONS FOR MAGMATISM DURING CONTINENTAL BREAKUP
SO NATURE
LA English
DT Article
ID crustal structure; flood basalts; norwegian margin; carolina trough; oceanic-crust; plume heads; mantle; convection; evolution; boundary
AB RIFTED continental margins commonly include sections of igneous rock more than twice as thick as normal oceanic crust. Explanations for this voluminous magmatic accretion during rifting include plume models1-3, which require a deep-seated thermal or chemical anomaly in upwelling mantle, and non-plume models4-7, which call on broad, shallow thermal anomalies and/;or rapid upwelling of mantle through the melting zone. New seismic models from two transects across the continent ocean transition on the US Atlantic margin8-10 confirm the presence of a 20-25-km-thick igneous section. Here we argue that the similarity of the crustal structure on these and two previous transects, spanning 1,000 km of the margin, and the association of thick igneous crust with the East Coast magnetic anomaly11 imply that the thick igneous section extends along the entire margin and may have a volume of as much as 3.2 x 10(6) km3. The distribution of volcanic and plutonic rocks, details of the seismic structure, and lack of independent evidence for a hotspot are difficult to reconcile with plume models and suggest that non-plume processes created the thick igneous crust.
RP HOLBROOK, WS (corresponding author), WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543, USA.
NR 35
TC 198
Z9 215
U1 0
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 433
EP 436
DI 10.1038/364433a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000051
DA 2026-03-10
ER

PT J
AU SOMMERER, JC
   OTT, E
AF SOMMERER, JC
   OTT, E
TI A PHYSICAL SYSTEM WITH QUALITATIVELY UNCERTAIN DYNAMICS
SO NATURE
LA English
DT Article
AB THE notion of determinism in classical dynamics has been eroded since Poincare's work1 led to the recognition that dynamical systems can exhibit chaotic behaviour, in which small perturbations grow exponentially fast. For a chaotic system, ubiquitous measurement errors, noise and computer round-off severely limit the time over which, given a precisely defined initial state, one can predict the detailed subsequent evolution. Practically speaking, the behaviour of such systems is quantitatively non-deterministic. Nevertheless, as the state of the system tends to be confined to an 'attractor' in phase space, at least its qualitative behaviour is predictable. Another challenge to determinism arises, however, when a system has competing attractors towards which an initial state may be drawn. Perturbations make it difficult to determine the fate of the system near the boundary between sets of initial conditions (basins) drawn toward different attractors, particularly if the boundary is geometrically convoluted2. Recently, mathematical mappings were found 3 for which the entire basin of a given attractor is riddled with 'holes' leading to a competing attractor. Here we present the first example of a physical system with this property. Perturbations in such a system render uncertain even the qualitative fate of a given initial state: experiments lose their reproducibility. We suggest that 'riddled' systems of this kind may be by no means uncommon.
C1 UNIV MARYLAND,DEPT PHYS,COLL PK,MD 20742.
   UNIV MARYLAND,DEPT ELECT ENGN,COLL PK,MD 20742.
C3 University System of Maryland; University of Maryland College Park; University System of Maryland; University of Maryland College Park
RP SOMMERER, JC (corresponding author), JOHNS HOPKINS UNIV,MS EISENHOWER RES CTR,APPL PHYS LAB,LAUREL,MD 20723, USA.
NR 9
TC 132
Z9 134
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 9
PY 1993
VL 365
IS 6442
BP 138
EP 140
DI 10.1038/365138a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LW442
UT WOS:A1993LW44200041
DA 2026-03-10
ER

PT J
AU COLEMAN, ML
   HEDRICK, DB
   LOVLEY, DR
   WHITE, DC
   PYE, K
AF COLEMAN, ML
   HEDRICK, DB
   LOVLEY, DR
   WHITE, DC
   PYE, K
TI REDUCTION OF FE(III) IN SEDIMENTS BY SULFATE-REDUCING BACTERIA
SO NATURE
LA English
DT Article
ID fatty-acid; ferric iron; sulfate
AB REDUCTION of ferric iron (Fe(III)) to ferrous iron (Fe(II)) is one of the most important geochemical reactions in anaerobic aquatic sediments because of its many consequences for the organic and inorganic chemistry of these environments1. In marine environments, sulphate-reducing bacteria produce H2S, which can reduce iron oxyhydroxides2 to form iron sulphides. The presence of siderite (FeCO3) in marine sediments is anomalous, however, as it is unstable in the presence of H2S. Previous work3,4 has suggested a bacterial origin of siderite. Here we describe geochemical and microbiological studies which suggest that contemporary formation of siderite concretions in a salt-marsh sediment results from the activity of sulphate-reducing bacteria. We find that, instead of reducing Fe(III) indirectly through the production of sulphide, some of these bacteria can reduce Fe(III) directly through an enzymatic mechanism, producing siderite rather than iron sulphides. Sulphate-reducing bacteria may thus be an important and previously unrecognized agent for Fe(III) reduction in aquatic sediments and ground waters.
C1 BP RES & ENGN CTR,SUNBURY TW16 7LN,MIDDX,ENGLAND.
   UNIV TENNESSEE,CTR ENVIRONM BIOTECHNOL,KNOXVILLE,TN 37932.
   US GEOL SURVEY,DIV WATER RESOURCES,RESTON,VA 22092.
   UNIV TENNESSEE,DEPT MICROBIOL,KNOXVILLE,TN 37996.
   OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831.
C3 BP; University of Tennessee System; University of Tennessee Knoxville; United States Department of the Interior; United States Geological Survey; University of Tennessee System; University of Tennessee Knoxville; United States Department of Energy (DOE); Oak Ridge National Laboratory
RP COLEMAN, ML (corresponding author), UNIV READING,POSTGRAD RES INST SEDIMENTOL,WHITEKNIGHTS,POB 227,READING RG6 2AB,BERKS,ENGLAND.
NR 25
TC 413
Z9 483
U1 3
U2 185
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 436
EP 438
DI 10.1038/361436a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300055
DA 2026-03-10
ER

PT J
AU BODNARENKO, SR
   CHALUPA, LM
AF BODNARENKO, SR
   CHALUPA, LM
TI STRATIFICATION OF ON AND OFF GANGLION-CELL DENDRITES DEPENDS ON GLUTAMATE-MEDIATED AFFERENT ACTIVITY IN THE DEVELOPING RETINA
SO NATURE
LA English
DT Article
ID action-potential activity; inner plexiform layer; cat retina; pharmacological modulation; mammalian retina; on-center; morphology; bipolar; beta; rod
AB A FUNDAMENTAL attribute of the vertebrate visual system is the segregation of ON and OFF pathways signalling increments and decrements of light1-4. In the mature retina, dendrites of ON- and OFF-centre retinal ganglion cells (RGCs) stratify in different sublaminae of the inner plexiform layer (IPL), and are differentially innervated by two types of bipolar cells which depolarize and hyperpolarize on exposure to light5-10. This stratification of ON and OFF RGCs is achieved by the gradual restriction of their dendrites which ramify throughout the IPL early in development11-14. The factors underlying this regressive event are unknown. Dendritic stratification occurs around the time that bipolar cells form synapses in the IPL15,16, which raises the possibility that synaptic activity is involved in this process. Here we test this hypothesis by treating the developing cat retina with the glutamate analogue 2-amino-4-phosphonobutyric acid (APB), which hyperpolarizes ON cone bipolar and rod bipolar cells, thereby preventing their release of glutamate17-19. We report that intraocular injection of APB during the period when dendritic stratification normally occurs prevents the formation of structurally segregated ON and OFF retinal pathways. These results provide evidence that glutamate-mediated afferent activity regulates the remodelling of RGC dendrites during development.
C1 UNIV CALIF DAVIS,CTR NEUROSCI,DAVIS,CA 95616.
C3 University of California System; University of California Davis
RP BODNARENKO, SR (corresponding author), UNIV CALIF DAVIS,DEPT PSYCHOL,DAVIS,CA 95616, USA.
NR 32
TC 191
Z9 214
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 144
EP 146
DI 10.1038/364144a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700048
PM 8100613
DA 2026-03-10
ER

PT J
AU STROM, M
   VOLLMER, P
   TAN, TJ
   GALLWITZ, D
AF STROM, M
   VOLLMER, P
   TAN, TJ
   GALLWITZ, D
TI A YEAST GTPASE-ACTIVATING PROTEIN THAT INTERACTS SPECIFICALLY WITH A MEMBER OF THE YPT/RAB FAMILY
SO NATURE
LA English
DT Article
ID gene-product; saccharomyces-cerevisiae; binding proteins; ras p21; gap; mutants; ras-p21; cloning; domain
AB MEMBERS of the Ras superfamily of GTP-binding proteins are involved in a variety of cellular processes, including signal transduction, cytoskeletal organization and protein transport1,2. GTP-binding proteins of the Ypt/Rab family direct vesicular protein transport in the secretory and endocytic pathways in the yeast Saccharomyces cerevisiae (Ypt proteins) and in mammalian systems (Rab proteinS)3,4. The cellular activity of monomeric GTP-binding proteins is influenced by proteins that regulate GDP/GTP exchange and GTP hydrolysis5. GTPase-activating proteins (GAPs) can increase the slow intrinsic GTPase activity of GTP-binding proteins by several orders of magnitude6,7. As GAPs modulate the activity of GTP-binding proteins, they are thought to give a biochemical handle on the functioning of Ypt/Rab proteins in transport vesicle budding and docking or fusion at donor and acceptor membranes1,2. We report here the first cloned GTPase-activating protein for the Ypt/Rab protein family. The gene, GYP6 (GAP of Ypt6 protein), encodes a protein of 458 amino acids which is highly specific for the Ypt6 protein and shows little or no cross-reactivity with other Ypt/Rab family members or with H-Ras p21.
C1 MAX PLANCK INST BIOPHYS CHEM, DEPT MOLEC GENET, POB 2841, W-3400 GOTTINGEN, GERMANY.
C3 Max Planck Society
NR 14
TC 150
Z9 168
U1 0
U2 13
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 736
EP 739
DI 10.1038/361736a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900060
PM 8441469
DA 2026-03-10
ER

PT J
AU DUNN, B
   STEARNS, T
   BOTSTEIN, D
AF DUNN, B
   STEARNS, T
   BOTSTEIN, D
TI SPECIFICITY DOMAINS DISTINGUISH THE RAS-RELATED GTPASES YPT1 AND SEC4
SO NATURE
LA English
DT Article
ID gene-product; protein gap; yeast; secretion; identification; superfamily; mechanism
AB THE essential Ras-related GTPases1,2 Ypt1 and Sec4 act at distinct stages of the secretion pathway in the yeast Saccharomyces cerevisiae: Ypt1 is required for vesicular transport from the endoplasmic reticulum to the Golgi apparatus, whereas Sec4 is required for fusion of secretory vesicles to the plasma membrane3-6. Here we use chimaeras of the two proteins to identify a 9-residue segment of Ypt1 that, when substituted for the analogous segment of Sec4, allows the chimaera to perform the minimal functions of both proteins in vivo. This segment corresponds to loop L7 of the p21ras crystal structure7. Substitution of a 24-residue Ypt1 segment, including the residues just mentioned, together with 12 residues of Ypt1 corresponding to the 'effector region' of p21ras (loop L2; refs 7, 8), transforms Sec4 into a fully functional Ypt1 protein without residual Sec4 function.
C1 UNIV CALIF SAN FRANCISCO,DEPT BIOCHEM & BIOPHYS,SAN FRANCISCO,CA 94143.
C3 University of California System; University of California San Francisco
RP DUNN, B (corresponding author), STANFORD UNIV,MED CTR,SCH MED,DEPT GENET,STANFORD,CA 94305, USA.
NR 27
TC 100
Z9 104
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 563
EP 565
DI 10.1038/362563a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300061
PM 8464499
DA 2026-03-10
ER

PT J
AU LAMBRECHT, WRL
   LEE, CH
   SEGALL, B
   ANGUS, JC
   LI, ZD
   SUNKARA, M
AF LAMBRECHT, WRL
   LEE, CH
   SEGALL, B
   ANGUS, JC
   LI, ZD
   SUNKARA, M
TI DIAMOND NUCLEATION BY HYDROGENATION OF THE EDGES OF GRAPHITIC PRECURSORS
SO NATURE
LA English
DT Article
ID chemical vapor-deposition; growth; carbon; surface; films; particles; mechanism; plasma; phase
AB How diamond films grow by chemical vapour deposition is now fairly well understood1,2, but the mechanism by which the diamond phase first nucleates is still unclear. Evidence is accumulating that atomic hydrogen, known to be important in diamond growth1,2, also plays an important role in nucleation3,4. The nature of the carbon precursor to diamond has been much debated2-9; although there is some evidence that graphite is formed before diamond nucleation2,5,6 and that diamond grows epitaxially on the graphite edges7, others have suggested10,11 that graphite formation is detrimental to diamond nucleation. Here we present calculations that suggest that diamond films can nucleate by the initial condensation of graphite and subsequent hydrogenation of the {1100BAR} prism planes along the edges of the graphite particles. If nucleation really does occur in this manner, the understanding that our model provides should assist in the development of methods for growing large diamond single crystals (now limited in part by secondary nucleation of independent crystals) and highly oriented epitaxial diamond films.
C1 CASE WESTERN RESERVE UNIV, DEPT CHEM ENGN, CLEVELAND, OH 44106 USA.
C3 University System of Ohio; Case Western Reserve University
RP LAMBRECHT, WRL (corresponding author), CASE WESTERN RESERVE UNIV, DEPT PHYS, CLEVELAND, OH 44106 USA.
NR 26
TC 260
Z9 277
U1 0
U2 48
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 607
EP 610
DI 10.1038/364607a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100046
DA 2026-03-10
ER

PT J
AU ZANA, R
   TALMON, Y
AF ZANA, R
   TALMON, Y
TI DEPENDENCE OF AGGREGATE MORPHOLOGY ON STRUCTURE OF DIMERIC SURFACTANTS
SO NATURE
LA English
DT Article
ID transmission electron-microscopy; aqueous nabr solutions; micelles; bromide; transition; system
AB SURFACTANT molecules in water form organized assemblies of various shapes, such as micelles and bilayer lamellae, which are of interest as analogues of biological structures, as model systems for studying complex phase behaviour and because of their technological importance, for example to the food and paint industries. The polar head groups are usually arranged randomly at the surface of these assemblies. We have studied the effect on the microstructure of these assemblies of imposing constraints on the head-group spacing. We investigate the structures formed by 'double-headed' surfactants in which two quaternary ammonium species (CmH2m+1N+(CH3)2) are linked at the level of the head groups by a hydrocarbon spacer (CsH2s). Here we report the microstructures formed by these dimeric surfactants with m = 12 and s = 2, 3 or 4 in aqueous solution, by rapidly cooling the micellar solutions and investigating the vitrified structures with transmission electron microscopy. The surfactants with a short spacer (s = 2, 3) form long, thread-like and entangled micelles even at low concentrations, whereas the corresponding monomeric ammonium surfactants can form only spherical micelles. The dimeric surfactants with s = 4 form spheroidal micelles. Thus short spacers (which impose reduced head-group separation) appear to promote lower spontaneous curvature in the assemblies. This approach may afford a new way to control amphiphile self-aggregation.
RP ZANA, R (corresponding author), TECHNION ISRAEL INST TECHNOL,DEPT CHEM ENGN,IL-32000 HAIFA,ISRAEL.
NR 23
TC 526
Z9 589
U1 0
U2 69
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 228
EP 230
DI 10.1038/362228a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600049
DA 2026-03-10
ER

PT J
AU LAFONCAZAL, M
   PIETRI, S
   CULCASI, M
   BOCKAERT, J
AF LAFONCAZAL, M
   PIETRI, S
   CULCASI, M
   BOCKAERT, J
TI NMDA-DEPENDENT SUPEROXIDE PRODUCTION AND NEUROTOXICITY
SO NATURE
LA English
DT Article
ID nitric-oxide synthase; amino-acid release; striatal neurons; nervous-system; glutamate; receptors; ischemia; quantification; cultures; injury
AB NEURONAL injury resulting from acute brain insults and some neurodegenerative diseases implicates N-methyl-D-aspartate (NMDA) glutamate receptors1-4. The fact that antioxidants reduce some types of brain damage suggests that oxygen radicals may have a roles5-7. It has been shown that mutations in Cu/Zn-superoxide dismutase (SOD), an enzyme catalysing superoxide (O2.-) detoxification in the cell, are linked to a familial form of amyotrophic lateral sclerosis (ALS)4. Here we report that O2.- is produced upon NMDA receptor stimulation in cultured cerebellar granule cells. Electron paramagnetic resonance was used to assess O2.- production that was due in part to the release of arachidonic acid. Activation of kainic acid receptors, or voltage-sensitive Ca2+ channels, did not produce detectable O2.-. We also find that the nitrone DMPO (5,5-dimethyl pyrroline 1-oxide), used as a spin trap, is more efficient than the nitric oxide synthase inhibitor, L-N(G)-nitroarginine, in reducing NMDA-induced neuronal death in these cultures.
C1 CRIPDOM,F-34172 CASTELNAU LEZ,FRANCE.
   UNIV AIX MARSEILLE 1,SREP,CNRS,URA 1412,F-13397 MARSEILLE 4,FRANCE.
C3 Centre National de la Recherche Scientifique (CNRS); Aix-Marseille Universite
RP LAFONCAZAL, M (corresponding author), CNRS,INSERM,CTR PHARMACOL ENDOCRINOL,RUE DE LA CARDONILLE,F-34094 MONTPELLIER 5,FRANCE.
NR 29
TC 1116
Z9 1167
U1 1
U2 71
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 5
PY 1993
VL 364
IS 6437
BP 535
EP 537
DI 10.1038/364535a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LQ667
UT WOS:A1993LQ66700057
PM 7687749
DA 2026-03-10
ER

PT J
AU MACDONALD, GM
   EDWARDS, TWD
   MOSER, KA
   PIENITZ, R
   SMOL, JP
AF MACDONALD, GM
   EDWARDS, TWD
   MOSER, KA
   PIENITZ, R
   SMOL, JP
TI RAPID RESPONSE OF TREELINE VEGETATION AND LAKES TO PAST CLIMATE WARMING
SO NATURE
LA English
DT Article
ID early holocene; sensitivity; parameters; sediments; forests; canada; ratios; limits
AB FUTURE greenhouse warming is expected to be particularly pronounced in boreal regions1, and consequent changes in vegetation in these regions may in turn affect global climate2-4. It is therefore important to establish how boreal ecosystems might respond to rapid changes in climate. Here we present palaeoecological evidence for changes in terrestrial vegetation and lake characteristics during an episode of climate warming that occurred between 5,000 and 4,000 years ago at the boreal treeline in central Canada. The initial transformation - from tundra to forest-tundra on land, which coincided with increases in lake productivity, pH and ratio of inflow to evaporation - took only 150 years, which is roughly equivalent to the time period often used in modelling the response of boreal forests to climate warming5,6. The timing of the treeline advance did not coincide with the maximum in high-latitude summer insolation predicted by Milankovitch theory7, suggesting that northern Canada experienced regionally asynchronous middle-to-late Holocene shifts in the summer position of the Arctic front. Such Holocene climate events may provide a better analogue for the impact of future global change on northern ecosystems than the transition from glacial to nonglacial conditions.
C1 UNIV WATERLOO,DEPT EARTH SCI,WATERLOO N2L 3G1,ONTARIO,CANADA.
   QUEENS UNIV,DEPT BIOL,PALEOECOL ENVIRONM ASSESSMENT & RES LAB,KINGSTON K7L 3N6,ONTARIO,CANADA.
C3 University of Waterloo; Queens University - Canada
RP MACDONALD, GM (corresponding author), MCMASTER UNIV,DEPT GEOG,HAMILTON L8S 4K1,ONTARIO,CANADA.
NR 33
TC 248
Z9 272
U1 4
U2 104
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 243
EP 246
DI 10.1038/361243a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400053
DA 2026-03-10
ER

PT J
AU SATO, A
   TSUKAMOTO, Y
AF SATO, A
   TSUKAMOTO, Y
TI NANOMETER-SCALE RECORDING AND ERASING WITH THE SCANNING TUNNELING MICROSCOPE
SO NATURE
LA English
DT Article
ID tunneling microscope; electrical-conductivity; bronzes
AB DATA storage on magnetic and optical disks and in semiconducting devices is being achieved at ever higher areal densities1,2. The use of the scanning tunnelling microscope (STM) for both data storage and nanofabrication has been explored recently3-9. These approaches use the STM tip to produce nanometre-scale marks or structures on a surface, sometimes with atomic precision. Most studies have, however, neglected erasure of recorded marks (an exception is described in ref. 10), despite the fact that erasure is essential for any practical recording device. Here we demonstrate the use of the STM for reproducible and reversible recording and erasing of marks about 10 nm in size. These are written at ambient temperature and pressure onto the surface of a composite medium consisting of a thin layer of a vanadate glass deposited on vanadium bronze, beta-NaxV2O5. The present recording speed of 1 ms is several orders of magnitude too slow for practical applications; this remains a challenge for future study.
RP SATO, A (corresponding author), NEC CORP LTD,FUNCT DEVICES RES LABS,4-1-1 MIYAZAKI,MIYAMAE KU,KAWASAKI,KANAGAWA 216,JAPAN.
NR 16
TC 75
Z9 83
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 431
EP 432
DI 10.1038/363431a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800052
DA 2026-03-10
ER

PT J
AU XIANG, XD
   HOU, JG
   CRESPI, VH
   ZETTL, A
   COHEN, ML
AF XIANG, XD
   HOU, JG
   CRESPI, VH
   ZETTL, A
   COHEN, ML
TI 3-DIMENSIONAL FLUCTUATION CONDUCTIVITY IN SUPERCONDUCTING SINGLE-CRYSTAL K3C60 AND RB3C60
SO NATURE
LA English
DT Article
ID high-tc superconductors; films
AB THE superconducting transition temperature, T(c), defines the point at which the free energies of the superconducting and normal states of a material become equal. Just above T(c), thermodynamic fluctuations produce small, transient regions of the superconducting state, giving rise to an anomalous increase in the normal-state conductivity known as paraconductivity. This situation is analogous to the fluctuating regions of correlated spins found near the Curie-Weiss transition in ferromagnets. Such, fluctuations are of theoretical significance in that they provide a direct probe of critical phenomena in general, and a stringent test of scaling theories, which describe the approach to the critical point. Paraconductivity effects are strongly dependent on the dimensionality of the system, although for conventional superconductors, three-dimensional fluctuation conductivity has to our knowledge never been observed. Here we report the observation of pure, three-dimensional paraconductivity in single crystals of the recently discovered1 superconductors K3C60 and Rb3C60. In addition to probing the critical state near T(c), these measurements allow the indirect determination of the residual, normal-state resistivity.
C1 LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720.
C3 United States Department of Energy (DOE); Lawrence Berkeley National Laboratory
RP XIANG, XD (corresponding author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA.
NR 17
TC 64
Z9 67
U1 0
U2 24
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 54
EP 56
DI 10.1038/361054a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800044
DA 2026-03-10
ER

PT J
AU COHEN, D
   CHUMAKOV, I
   WEISSENBACH, J
AF COHEN, D
   CHUMAKOV, I
   WEISSENBACH, J
TI A 1ST-GENERATION PHYSICAL MAP OF THE HUMAN GENOME
SO NATURE
LA English
DT Article
ID yeast artificial chromosm; human y-chromosome; dna; strategy; clones; library; elegans; vectors
AB SETS of ordered overlapping cloned genomic DNA fragments that span each of the human chromosomes are urgently needed for identification of human disease genes. Such a physical map also provides unique material to study the structure and function of the genome. We have therefore exhaustively analysed the CEPH yeast artificial chromosome (YAC) library, which contains 33,000 clones, whose insert size was individually determined. These YACs have an average length of 0.9 megabases and cover the equivalent of 10 haploid genomes. Several mapping techniques were combined to provide multiple sources of structural information for most of these clones. Finally, the library was screened with more than 2,000 genetic markers quasiuniformly distributed over 90% of the genome. These results should allow the scientific community to construct detailed maps of all human chromosomes. Moreover, we propose a data analysis strategy that produces a first-generation integrated map covering most of the human genome.
C1 GENETHON,F-91002 EVRY,FRANCE.
   INST PASTEUR,CNRS,URA 1445,F-75014 PARIS,FRANCE.
C3 Pasteur Network; Universite Paris Cite; Institut Pasteur Paris; Centre National de la Recherche Scientifique (CNRS)
RP COHEN, D (corresponding author), FDN JEAN DAUSSET,CEPH,27 RUE JULIETTE DODU,F-75010 PARIS,FRANCE.
NR 19
TC 476
Z9 509
U1 1
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 698
EP 701
DI 10.1038/366698a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500073
PM 8259213
DA 2026-03-10
ER

PT J
AU ARDAVIN, C
   WU, L
   LI, CL
   SHORTMAN, K
AF ARDAVIN, C
   WU, L
   LI, CL
   SHORTMAN, K
TI THYMIC DENDRITIC CELLS AND T-CELLS DEVELOP SIMULTANEOUSLY IN THE THYMUS FROM A COMMON PRECURSOR POPULATION
SO NATURE
LA English
DT Article
ID hematopoietic stem-cells; langerhans cells; bone-marrow; mouse
AB DENDRITIC cells, a minor cell population in lymphoid tissues, are specialized for presentation of antigenic peptides to T lymphocytes1. Thymic dendritic cells are involved in the deletion of self-reactive T lymphocytes2,3. Although all dendritic cells are ultimately of bone-marrow origin4-7, it has not been clear whether thymic dendritic cells are produced in the adult thymus from a precursor cell or whether they migrate there preformed from the periphery. Recently we isolated from adult mouse thymus a population of early T precursors that could still form B lymphocytes, but not erythroid or myeloid cells, when transferred intravenously8,9. Here we show that these thymic lymphoid precursor cells, as well as bone-marrow haematopoietic stem cells, are able to form both dendritic cells and T-cell progeny when transferred into an irradiated thymus. Such linked development may ensure that developing T cells are negatively selected predominantly by self antigens presented on newly formed thymic dendritic cells.
C1 ROYAL MELBOURNE HOSP, WALTER & ELIZA HALL INST MED RES, PARKVILLE, VIC 3050, AUSTRALIA.
C3 Melbourne Health; Royal Melbourne Hospital; Walter & Eliza Hall Institute
NR 18
TC 569
Z9 637
U1 0
U2 13
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 761
EP 763
DI 10.1038/362761a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000060
PM 8469288
DA 2026-03-10
ER

PT J
AU SHANKLAND, TJ
   PEYRONNEAU, J
   POIRIER, JP
AF SHANKLAND, TJ
   PEYRONNEAU, J
   POIRIER, JP
TI ELECTRICAL-CONDUCTIVITY OF THE EARTHS LOWER MANTLE
SO NATURE
LA English
DT Article
ID magnesiowustite; perovskite; olivine
AB THE electrical conductivity of the Earth's lower mantle constrains both the propagation to the surface of geomagnetic disturbances in the core and the nature of core-mantle coupling. Extrapolations of laboratory measurements on materials representative of the lower mantle agree weakly1,2 or not at all3,4 with recent geophysical models5-8 of lower-mantle electrical conductivity based on variations of magnetic and electrical fields measured at the Earth's surface. Here we report d.c. conductivity measurements on samples with compositions approximating that of the lower mantle, at pressures of 1.2 to 40 GPa and temperatures in the range 20 to 400-degrees-C. Our results agree with some of those obtained previously1,2. But in contrast to this previous work, we extrapolate the results to lower-mantle conditions by adopting a functional form for the conductivity that incorporates the effect of pressure as well as temperature. The resulting estimates of conductivity are in agreement with the geophysical determinations5-8. We find that, because of a very weak dependence on temperature, pressure and composition, the conductivity is likely to vary by no more than about a factor of five across the entire lower mantle, reaching a maximum value of only 3-10 S m-1. Lateral temperature variations as large as a few hundred degrees will therefore be hard to detect geophysically, and the compositionally distinct D'' layer at the base of the lower mantle remains the only possible location for a highly conducting layer.
C1 INST PHYS GLOBE,DEPT GEOMAT,F-75252 PARIS 05,FRANCE.
C3 Universite Paris Cite
NR 23
TC 130
Z9 134
U1 0
U2 20
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 453
EP 455
DI 10.1038/366453a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800060
DA 2026-03-10
ER

PT J
AU RANDEL, WJ
   GILLE, JC
   ROCHE, AE
   KUMER, JB
   MERGENTHALER, JL
   WATERS, JW
   FISHBEIN, EF
   LAHOZ, WA
AF RANDEL, WJ
   GILLE, JC
   ROCHE, AE
   KUMER, JB
   MERGENTHALER, JL
   WATERS, JW
   FISHBEIN, EF
   LAHOZ, WA
TI STRATOSPHERIC TRANSPORT FROM THE TROPICS TO MIDDLE LATITUDES BY PLANETARY-WAVE MIXING
SO NATURE
LA English
DT Article
ID potential vorticity; numerical-model; breaking; n2o
AB TRANSPORT of air from the troposphere to the stratosphere takes place mainly in the tropics1. By studying satellite records of the dispersal of volcanic aerosols from tropical eruptions, Trepte and Hitchman2 concluded that there is a barrier inhibiting the transport of stratospheric air from the tropics to middle latitude, raising the question of how stratospheric material that has been transported from the troposphere is subsequently conveyed to higher latitudes. Here we present global maps of nitrous oxide and water mixing ratios obtained by the Upper Atmosphere Research Satellite. We see strong latitudinal gradients in these trace species, confirming the existence of a barrier to transport. But superimposed on this background structure we also see planetary-scale 'tongues' of tropical stratospheric air extending out into middle latitudes, and time sequences show irreversible mixing from the tropics into middle latitudes. Such episodes could be responsible for transporting significant quantities of stratospheric air across the tropical barrier.
C1 LOCKHEED PALO ALTO RES LABS,PALO ALTO,CA 94304.
   JET PROP LAB,PASADENA,CA 91109.
   UNIV EDINBURGH,DEPT METEOROL,EDINBURGH EH9 3JZ,MIDLOTHIAN,SCOTLAND.
C3 Lockheed Martin; National Aeronautics & Space Administration (NASA); NASA Jet Propulsion Laboratory (JPL); University of Edinburgh
RP RANDEL, WJ (corresponding author), NATL CTR ATMOSPHER RES,BOULDER,CO 80307, USA.
NR 23
TC 141
Z9 145
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 533
EP 535
DI 10.1038/365533a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100048
DA 2026-03-10
ER

PT J
AU BEGUN, DJ
   AQUADRO, CF
AF BEGUN, DJ
   AQUADRO, CF
TI AFRICAN AND NORTH-AMERICAN POPULATIONS OF DROSOPHILA-MELANOGASTER ARE VERY DIFFERENT AT THE DNA LEVEL
SO NATURE
LA English
DT Article
ID restriction-map variation; natural-populations; phenotypic variation; genetic-variation; genic variation; locus region; polymorphism; endonucleases; patterns; flow
AB UNDERSTANDING genetic evolution within species requires an accurate description of variation within and between populations and the ability to distinguish between the potential causes of an observed distribution of variation. In the cosmopolitan species Drosophila melanogaster, previous studies suggested that gene flow within and between continents is extensive1 and that most of the nuclear gene variation is found within, rather than among, populations2,3. Here we present evidence that a population from Zimbabwe is more than twice as variable as those from the United States of America at the DNA sequence level, that most variants are not shared between the two geographic regions, and that there are nearly fixed differences between the Zimbabwe and USA samples in genomic regions experiencing low recombination rates. It appears that there is an unappreciated degree of population structure in D. melanogaster and that equilibrium models of molecular evolution are inappropriate for this species.
RP BEGUN, DJ (corresponding author), CORNELL UNIV, GENET & DEV SECT, BIOTECHNOL BLDG, ITHACA, NY 14853 USA.
FU NIGMS NIH HHS [R01 GM036431] Funding Source: Medline
NR 26
TC 269
Z9 302
U1 0
U2 20
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 548
EP 550
DI 10.1038/365548a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100054
PM 8413609
DA 2026-03-10
ER

PT J
AU BALMFORD, A
   THOMAS, ALR
   JONES, IL
AF BALMFORD, A
   THOMAS, ALR
   JONES, IL
TI AERODYNAMICS AND THE EVOLUTION OF LONG TAILS IN BIRDS
SO NATURE
LA English
DT Article
ID kestrel falco-tinnunculus; sexual selection; female choice; lifting-line; flight; models; wings; flow; wake
AB TWO problems limit the interpretation of recent experiments1-3 supporting Darwin's4 suggestion that female choice for ornate males may account for the evolution of long tails in birds. First. in some species tail elongation may have been favoured by natural rather than sexual selection. Second, it is unclear how female preferences for elaborate males have evolved, because current tests of competing models are often inconclusive5-7. We have integrated aerodynamics theory with comparative data on sexual dimorphism in tail length to evaluate the flight costs of different forms of tail elongation. We report here that long tails with shallow forks are aerodynamically optimal, exhibit correspondingly low sexual dimorphism and may therefore have evolved under natural selection. Other long-tail types impair flight and show greater sexual dimorphism, but variation in their initial evolutionary cost suggests differences in how female preferences for them may have evolved.
C1 UNIV CAMBRIDGE,DEPT ZOOL,CAMBRIDGE CB2 3EJ,ENGLAND.
C3 University of Cambridge
NR 25
TC 150
Z9 154
U1 4
U2 60
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 18
PY 1993
VL 361
IS 6413
BP 628
EP 631
DI 10.1038/361628a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KM776
UT WOS:A1993KM77600061
DA 2026-03-10
ER

PT J
AU KRAMER, GJ
   VANSANTEN, RA
   EMEIS, CA
   NOWAK, AK
AF KRAMER, GJ
   VANSANTEN, RA
   EMEIS, CA
   NOWAK, AK
TI UNDERSTANDING THE ACID BEHAVIOR OF ZEOLITES FROM THEORY AND EXPERIMENT
SO NATURE
LA English
DT Article
ID bronsted sites; catalysts; abinitio; methane
AB ZEOLITES are microporous aluminosilicates which, in their protonated form, act as solid catalysts1, and are widely used in the oil and petrochemical industries for processes such as cracking, isomerization and alkylation if hydrocarbons2. The proposed mechanisms3-5 of these processes mostly involve proton transfer and formation of carbenium or carbonium ions as reactive intermediates, but the detailed function of the zeolite and in particular the relation between acidity and catalytic activity is not well understood. Here we report experimental and theoretical studies of denterium-hydrogen exchange between deuterated methane and protonated zeolites - a prototypical heterogeneous catalytic reaction between a hydrocarbon and an acid zeolite. We monitored this slow exchange reaction in two different zeolites using infrared spectroscopy, and used ab initio quantum chemistry calculations to determine both the reaction mechanism and the acidity-activity relationship. Combining our theoretical results with recent estimates8-11 of the acidity differences within zeolites enables us to reproduce the experimentally observed reaction rates and thus to obtain a detailed microscopic picture of this heterogeneous catalytic process.
RP KRAMER, GJ (corresponding author), SHELL INT RES MAATSCHAPPIJ BV,KONINKLIJKE SHELL LAB,POB 3003,1003 AA AMSTERDAM,NETHERLANDS.
NR 24
TC 277
Z9 288
U1 1
U2 118
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 529
EP 531
DI 10.1038/363529a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900044
DA 2026-03-10
ER

PT J
AU HOWLE, L
   BEHRINGER, RP
   GEORGIADIS, J
AF HOWLE, L
   BEHRINGER, RP
   GEORGIADIS, J
TI VISUALIZATION OF CONVECTIVE FLUID-FLOW IN A POROUS-MEDIUM
SO NATURE
LA English
DT Article
ID benard convection; heat-transfer
AB WHEN a horizontal layer of fluid is heated from below, it may undergo Rayleigh-Benard convection (RBC), leading to the spontaneous appearance of regular patterns of fluid flow1. The shadowgraph technique2, which allows visualization of the convection patterns, has assisted in developing an understanding of RBC. Related to RBC is convection in a fluid permeating a porous medium (called Horton-Rodgers-Lapwood convection or HRLC) when it is heated from below3-7. HRLC is relevant to geothermal applications and to flow in soils. Pattern formation in HRLC is less easily visualized by shadowgraph techniques because of the difficulties of transmitting light through the porous medium. Here we show how these difficulties can be overcome by constructing porous media in which the interfaces between solid and liquid are either parallel or perpendicular to the confining boundaries of the experimental system. Convection in such a medium can be visualized using conventional shadowgraph methods, and we compare the stationary flow patterns observed against measurements of heat transport.
C1 DUKE UNIV,DEPT PHYS,DURHAM,NC 27706.
   UNIV ILLINOIS,DEPT MECH & IND ENGN,URBANA,IL 61801.
C3 Duke University; University of Illinois System; University of Illinois Urbana-Champaign
RP HOWLE, L (corresponding author), DUKE UNIV,DEPT MECH ENGN & MAT SCI,DURHAM,NC 27706, USA.
NR 21
TC 37
Z9 39
U1 0
U2 16
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 230
EP 232
DI 10.1038/362230a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600050
DA 2026-03-10
ER

PT J
AU GOPALKRISHNA
   WIITA, PJ
AF GOPALKRISHNA
   WIITA, PJ
TI RECONCILING THE MAGNETIC-FIELD STRUCTURES SEEN IN VARIABLE ACTIVE GALACTIC NUCLEI WITH THE UNIFIED SCHEME
SO NATURE
LA English
DT Article
ID bl lacertae objects; radio outbursts; galaxy; polarization; models
AB IN the orientation-based unification scheme for active galaxies, the most variable active galactic nuclei-the BL Lacertae objects and highly polarized quasars (HPQs)-correspond to radio galaxies with their relativistic jets oriented close to our line of sight1-7. This otherwise successful scheme has recently been challenged by radio polarimetric very-long-baseline interferometry8,9, which reveals different magnetic field structures in the knots of synchrotron emission identified with shocks in these jets, For BL Lacs the field is generally perpendicular to the jet, whereas no such trend is apparent for HPQs. This dichotomy has led to the claim that luminous BL Lacs and HPQs are inherently different types of object10. Here we propose that this difference can be readily explained within the unified scheme by the effect of relativistic aberration: at small viewing angles, the observed knot emission arises primarily from the freshly excited plasma of the shock front, whereas at larger angles, Doppler-boosted emission from the slower, post-shock plasma is the dominant contribution. We identify the former case with BL Lacs and the latter with HPQs.
C1 TATA INST FUNDAMENTAL RES,NATL CTR RADIO ASTROPHYS,POONA 411007,INDIA.
   GEORGIA STATE UNIV,DEPT PHYS & ASTRON,ATLANTA,GA 30303.
C3 Tata Institute of Fundamental Research (TIFR); National Centre for Radio Astrophysics (NCRA), Pune; University System of Georgia; Georgia State University
RP GOPALKRISHNA (corresponding author), SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218, USA.
NR 30
TC 9
Z9 9
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 142
EP 144
DI 10.1038/363142a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100040
DA 2026-03-10
ER

PT J
AU BROADIE, K
   BATE, M
AF BROADIE, K
   BATE, M
TI INNERVATION DIRECTS RECEPTOR SYNTHESIS AND LOCALIZATION IN DROSOPHILA EMBRYO SYNAPTOGENESIS
SO NATURE
LA English
DT Article
ID acetylcholine-receptors; cell; prospero; protein; agrin
AB IN the Drosophila embryo, motor neurons form stereotyped synapses (neuromuscular junctions) on identified muscles1-3. We have used a mutant (prospero) that removes or delays innervation4,5  to assay the role of the presynaptic motor neuron in the development of the receptive field of the postsynaptic muscle. prospero (pros) is not expressed in the muscles or their precursors. Here we find that the muscle defines the correct synaptic zone in the absence of the motor neuron by restricting putative guidance molecules to this specialized membrane region. Furthermore, the muscle expresses functional transmitter receptors at the correct developmental time without innervation. On the other hand, the muscle does not localize receptors to the synapse without instruction from the motor neuron, nor does a second, much larger, synthesis of receptors occur in muscles deprived of innervation. In muscles receiving delayed innervation, or muscles innervated at aberrant synaptic sites, both receptor clustering and receptor synthesis are delayed or redirected, consistent with the new pattern of innervation. We conclude that the muscle autonomously defines the synaptic site, whereas the motor neuron directs the development of the muscle's receptive field by stimulating the synthesis and localization of transmitter receptors.
RP BROADIE, K (corresponding author), UNIV CAMBRIDGE,DEPT ZOOL,DOWNING ST,CAMBRIDGE CB2 3EJ,ENGLAND.
NR 25
TC 106
Z9 125
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 350
EP 353
DI 10.1038/361350a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000057
PM 8426654
DA 2026-03-10
ER

PT J
AU RUTTEN, RGM
   DHILLON, VS
   HORNE, K
   KUULKERS, E
   VANPARADIJS, J
AF RUTTEN, RGM
   DHILLON, VS
   HORNE, K
   KUULKERS, E
   VANPARADIJS, J
TI SPECTRALLY RESOLVED ECLIPSE MAPS OF THE ACCRETION DISK IN UX-URSAE-MAJORIS
SO NATURE
LA English
DT Article
ID images
AB ACCRETION disks play an important role in many astrophysical environments, such as active galactic nuclei, protostellar systems, X-ray binaries and cataclysmic variables. The lack of spatially resolved information, however, has meant that theoretical models for accretion disks are in general poorly constrained by observations. Here we use the shape of the light curves from an eclipsing cataclysmic variable, UX Ursae Majoris, to reconstruct the spectral energy distribution (in the range 3,600-10,000 angstrom) across the face of an accretion disk. The spectral resolution is sufficient to reveal both the radial dependence of absorption and emission line features within the disk, and the spectral details of the bright spot formed at the point where the accretion stream from the secondary star collides with the disk. Such detailed reconstructions of accretion-disk spectra should help to bridge the gap between observations and theoretical models.
C1 CTR HIGH ENERGY ASTROPHYS,1098 SJ AMSTERDAM,NETHERLANDS.
   ROYAL GREENWICH OBSERV,E-38780 SANTA CRUZ PALMA,SPAIN.
   SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218.
C3 Space Telescope Science Institute
RP RUTTEN, RGM (corresponding author), ASTRON INST ANTON PANNEKOEK,KRUISLAAN 403,1098 SJ AMSTERDAM,NETHERLANDS.
NR 11
TC 33
Z9 34
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 518
EP 520
DI 10.1038/362518a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300045
DA 2026-03-10
ER

PT J
AU MILLER, EK
   BLUM, JD
   FRIEDLAND, AJ
AF MILLER, EK
   BLUM, JD
   FRIEDLAND, AJ
TI DETERMINATION OF SOIL EXCHANGEABLE-CATION LOSS AND WEATHERING RATES USING SR ISOTOPES
SO NATURE
LA English
DT Article
ID chemistry; ratios; precipitation; sr-87/sr-86; watersheds
AB To assess the response of forests to a changing chemical environment, a means is needed for separating the total cation export from the watershed into a component derived from mineral weathering reactions and a component due to the removal of exchangeable (plant-available) cations in the soil1-3. We show that this separation may be possible by using Sr-87/Sr-86 ratios as a tracer of cation sources in stream water. Our measurements from a high-elevation forest ecosystem in the Adirondack mountains, New York, indicate that mineral weathering reactions contribute about 70% and soil cation-exchange reactions about 30% of annual strontium exports. Based on these results and the ratios of major cations to strontium in the local glacial till, we estimate the release of Ca2+, Mg2+, K+ and Na+ owing to weathering. The present weathering rate seems adequate to replace annual losses of cations from the total soil exchangeable pool, suggesting that the watershed is not in immediate danger of acidification from atmospheric deposition. But as our strontium isotope data indicate that 50-60% of the strontium in the organic-soil-horizon exchangeable and vegetation cation pools has an atmospheric origin, reduction of atmospheric cation inputs4 coupled with continued strong-acid anion inputs5 may result in significant depletion of this cation reservoir.
C1 DARTMOUTH COLL,ENVIRONM STUDIES PROGRAM,HANOVER,NH 03755.
C3 Dartmouth College
RP MILLER, EK (corresponding author), DARTMOUTH COLL,DEPT EARTH SCI,HANOVER,NH 03755, USA.
NR 19
TC 281
Z9 343
U1 1
U2 75
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 438
EP 441
DI 10.1038/362438a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400079
DA 2026-03-10
ER

PT J
AU MARTINOIA, E
   GRILL, E
   TOMMASINI, R
   KREUZ, K
   AMRHEIN, N
AF MARTINOIA, E
   GRILL, E
   TOMMASINI, R
   KREUZ, K
   AMRHEIN, N
TI ATP-DEPENDENT GLUTATHIONE S-CONJUGATE EXPORT PUMP IN THE VACUOLAR MEMBRANE OF PLANTS
SO NATURE
LA English
DT Article
ID barley mesophyll protoplasts; rat-liver; transport; vesicles; atpases; malate; acid
AB PLANTS are exposed to many potentially phytotoxic foreign compounds, such as microbial toxins and agrochemicals (xenobiotics). Detoxification and elimination of these compounds within or from the cell is a prerequisite for their survival. Metabolism and detoxification of xenobiotics are remarkably similar in plants and animals and can generally be divided into three phases1,2. In the first phase, a foreign compound may be oxidized, reduced or hydrolysed to introduce or reveal a functional group. In a second step, the activated xenobiotic is conjugated to either glutathione, glucuronate (animals), or malonyl or glucosyl moieties (plants) by the respective transferases. In animals the third step, excretion of conjugated xenobiotics to the extracellular medium, is mediated by a specific ATPase1,3-5. In plants, instead of excretion, conjugates of xenobiotics appear to be stored in the large central vacuole6, but it is not known how they are transported into this organelle. We show here that glutathione S-conjugate uptake into the vacuole is mediated by a specific ATPase which is remarkably similar to the glutathione S-conjugate export pumps in the canalicular membrane of mammalian liver.
C1 CIBA GEIGY AG,CH-4002 BASEL,SWITZERLAND.
C3 Novartis
RP MARTINOIA, E (corresponding author), SWISS FED INST TECHNOL,INST PLANT SCI,SONNEGGSTR 5,CH-8092 ZURICH,SWITZERLAND.
NR 25
TC 311
Z9 346
U1 1
U2 41
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 247
EP 249
DI 10.1038/364247a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300060
DA 2026-03-10
ER

PT J
AU JAIN, JN
   MCCAFFREY, PG
   MINER, Z
   KERPPOLA, TK
   LAMBERT, JN
   VERDINE, GL
   CURRAN, T
   RAO, A
AF JAIN, JN
   MCCAFFREY, PG
   MINER, Z
   KERPPOLA, TK
   LAMBERT, JN
   VERDINE, GL
   CURRAN, T
   RAO, A
TI THE T-CELL TRANSCRIPTION FACTOR NFAT(P) IS A SUBSTRATE FOR CALCINEURIN AND INTERACTS WITH FOS AND JUN
SO NATURE
LA English
DT Article
ID dna-binding activity; cyclosporine-a; signal transduction; activation; identification; fk-506; protein; domains; association; enhancer
AB TRANSCRIPTION of lymphokine genes in activated T cells is inhibited by the immunosuppressive agents cyclosporin A and FK506, which act by blocking the phosphatase activity of calcineurin1-3. NFAT, a DNA-binding protein required for interleukin-2 gene transcription, is a potential target for calcineurin, cyclosporin A and FK506(4-11). NFAT contains a subunit (NFAT(p)) which is present in unstimulated T cells and which forms a complex with Fos and Jun proteins in the nucleus of activated T cells9,11. Here we report that NFAT(p) is a DNA-binding phosphoprotein of relative molecular mass approximately 120,000 and is a substrate for calcineurin in vitro. Purified NFAT(p) forms DNA-protein complexes with recombinant Jun homodimers or Jun-Fos heterodimers; the DNA-binding domains of Fos and Jun are essential for the formation of the NFAT(p)-Fos-Jun-DNA complex. The interaction between the lymphoid-specific factor NFAT(p) and the ubiquitous transcription factors Fos and Jun provides a novel mechanism for combinatorial regulation of interleukin-2 gene transcription, which integrates the calcium-dependent and the protein-kinase C-dependent pathways of T-cell activation.
C1 HARVARD UNIV,SCH MED,DANA FARBER CANC INST,DIV TUMOR BIOL,BOSTON,MA 02115.
   HARVARD UNIV,SCH MED,DEPT PATHOL,BOSTON,MA 02115.
   ROCHE INST MOLEC BIOL,ROCHE RES CTR,DEPT MOLEC ONCOL & VIROL,NUTLEY,NJ 07110.
   HARVARD UNIV,DEPT CHEM,CAMBRIDGE,MA 02138.
C3 Harvard University; Harvard University Medical Affiliates; Dana-Farber Cancer Institute; Harvard Medical School; Harvard University; Harvard Medical School; Roche Holding; Roche Holding USA; Harvard University
NR 28
TC 723
Z9 791
U1 0
U2 26
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 352
EP 355
DI 10.1038/365352a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600056
PM 8397339
DA 2026-03-10
ER

PT J
AU LANDRY, SJ
   ZEILSTRARYALLS, J
   FAYET, O
   GEORGOPOULOS, C
   GIERASCH, LM
AF LANDRY, SJ
   ZEILSTRARYALLS, J
   FAYET, O
   GEORGOPOULOS, C
   GIERASCH, LM
TI CHARACTERIZATION OF A FUNCTIONALLY IMPORTANT MOBILE DOMAIN OF GROES
SO NATURE
LA English
DT Article
ID escherichia-coli; protein; chaperonin; atp
AB ALTHOUGH genetic1 and biochemical2,3 evidence has established that GroES is required for the full function of the molecular chaperone, GroEL, little is known about the molecular details of their interaction. GroES enhances the cooperativity of ATP binding and hydrolysis by GroEL (refs 4, 5) and is necessary for release and folding of several GroEL substrates6. Here we report that native GroES has a highly mobile and accessible polypeptide loop whose mobility and accessibility are lost upon formation of the GroES/GroEL complex. In addition, lesions present in eight independently isolated mutant groES alleles map in the mobile loop. Studies with synthetic peptides suggest that the loop binds in a hairpin conformation at a site on GroEL that is distinct from the substrate-binding site. Flexibility may be required in the mobile loops on the GroES seven-mer to allow them to bind simultaneously to sites on seven GroEL subunits, which may themselves be able to adopt different arrangements, and thus to modulate allosterically GroEL/substrate affinity.
C1 UNIV TEXAS,SW MED CTR,DALLAS,TX 75235.
   UNIV GENEVA,DEPT BIOCHIM MED,CH-1211 GENEVA 4,SWITZERLAND.
   UNIV UTAH,MED CTR,SALT LAKE CITY,UT 84132.
C3 University of Texas System; University of Texas Southwestern Medical Center; University of Texas Dallas; University of Geneva; Utah System of Higher Education; University of Utah
NR 24
TC 213
Z9 225
U1 0
U2 14
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 255
EP 258
DI 10.1038/364255a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300063
PM 8100614
DA 2026-03-10
ER

PT J
AU LEE, J
   ISHIHARA, A
   THERIOT, JA
   JACOBSON, K
AF LEE, J
   ISHIHARA, A
   THERIOT, JA
   JACOBSON, K
TI PRINCIPLES OF LOCOMOTION FOR SIMPLE-SHAPED CELLS
SO NATURE
LA English
DT Article
ID neuronal growth cone; leading-edge; flow; microfilament; microtubules; organization; fibroblasts; movement; culture; invitro
AB MOVING cells display a variety of shapes and modes of locomotion1, but it is not clear how motility at the molecular level relates to the locomotion of a whole cell, a problem compounded in studies of cells with complex shapes2-5. A striking feature of fish epidermal keratocyte locomotion is its apparent simplicity6. Here we present a kinematic description of locomotion which is consistent with the semicircular shape and persistent 'gliding' motion of fish epidermal keratocytes. We propose that extension of the front and retraction of the rear of these cells occurs perpendicularly to the cell edge, and that a graded distribution of extension and retraction rates along the cell margin maintains cell shape and size during locomotion. Evidence for this description is provided by the predicted circumferential motion of lamellar features and the curvature of 'photo-marked' lines within specific molecular components of moving keratocytes. Our description relates the dynamics of molecular assemblies to the movement of a whole cell.
C1 UNIV N CAROLINA,LINEBERGER CANC RES CTR,CHAPEL HILL,NC 27599.
   UNIV CALIF SAN FRANCISCO,DEPT BIOCHEM,SAN FRANCISCO,CA 94143.
   UNIV CALIF SAN FRANCISCO,DEPT BIOPHYS,SAN FRANCISCO,CA 94143.
C3 University of North Carolina; University of North Carolina Chapel Hill; University of California System; University of California San Francisco; University of California System; University of California San Francisco
RP LEE, J (corresponding author), UNIV N CAROLINA,DEPT CELL BIOL & ANAT,CHAPEL HILL,NC 27599, USA.
NR 21
TC 199
Z9 228
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 11
PY 1993
VL 362
IS 6416
BP 167
EP 171
DI 10.1038/362167a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KR028
UT WOS:A1993KR02800063
PM 8450887
DA 2026-03-10
ER

PT J
AU TAO, MH
   LEVY, R
AF TAO, MH
   LEVY, R
TI IDIOTYPE GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR FUSION PROTEIN AS A VACCINE FOR B-CELL LYMPHOMA
SO NATURE
LA English
DT Article
ID gene-transfer; immunity; antigen; potent; antibody; molecules; receptors; invivo
AB To produce a vaccine against cancer, antigens must be found that are preferentially expressed by tumour cells and can induce an immune response against the tumour. The variable regions of the immunoglobulin molecules expressed on malignant B cells (idiotypes) are tumour-specific, but are weak immunogens. To induce an immune response in animals or humans, the idiotypic protein has therefore to be chemically coupled to a strongly immunogenic protein and mixed with an adjuvant1-8. The resulting response can protect animals from subsequent tumour challenge, and cure animals with established tumours in combination with chemotherapy. Granulocyte-macrophage colony-stimulating factor (GM-CSF) augments antigen presentation in a variety of cells9-12. Here we show that by fusing a tumour-derived idiotype to GM-CSF, it can be converted into a strong immunogen capable of inducing idiotype-specific antibodies without other carrier proteins or adjuvants and of protecting recipient animals from challenge with an otherwise lethal dose of tumour cells. This approach may be applicable to the design of vaccines for a variety of other diseases.
C1 STANFORD UNIV, MED CTR, SCH MED, DEPT MED, DIV ONCOL, STANFORD, CA 94305 USA.
C3 Stanford University
NR 30
TC 280
Z9 337
U1 1
U2 9
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 755
EP 758
DI 10.1038/362755a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000058
PM 8469286
DA 2026-03-10
ER

PT J
AU HAO, Y
   CRENSHAW, T
   MOULTON, T
   NEWCOMB, E
   TYCKO, B
AF HAO, Y
   CRENSHAW, T
   MOULTON, T
   NEWCOMB, E
   TYCKO, B
TI TUMOR-SUPPRESSOR ACTIVITY OF H19 RNA
SO NATURE
LA English
DT Article
ID normal human chromosome-11; wilms-tumor; cell-differentiation; gene; expression; mouse; tumorigenicity; alleles
AB Loss of heterozygosity in certain human embryonal tumours implicates a tumour-suppressor gene at chromosome 11p15.5 and selective loss of maternal alleles suggests that this gene is paternally imprinted1-4. The human H19 gene maps to 11p15.5, is expressed in differentiating fetal cells5-11 and is paternally imprinted12-16. We report here that two embryonal tumour cell lines, RD and G401, showed growth retardation and morphological changes when transfected with an H19 expression construct. More importantly, clonogenicity in soft agar and tumorigenicity in nude mice were abrogated in the G401-H19 transfectants. In addition to demonstrating its tumour-suppressor potential, this transfection system should help structural and functional studies of the enigmatic H19 gene.
C1 COLUMBIA UNIV COLL PHYS & SURG,DEPT PATHOL,DIV ONCOL,NEW YORK,NY 10032.
   COLUMBIA UNIV COLL PHYS & SURG,DEPT PATHOL,DIV NEUROPATHOL,NEW YORK,NY 10032.
   COLUMBIA UNIV COLL PHYS & SURG,DEPT PEDIAT,DIV PEDIAT HEMATOL ONCOL,NEW YORK,NY 10032.
   NYU,SCH MED,DEPT PATHOL,NEW YORK,NY 10016.
C3 Columbia University; Columbia University; Columbia University; New York University
NR 24
TC 598
Z9 638
U1 0
U2 17
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 764
EP 767
DI 10.1038/365764a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200067
PM 7692308
DA 2026-03-10
ER

PT J
AU HAMILTON, DP
   BURNS, JA
AF HAMILTON, DP
   BURNS, JA
TI EJECTION OF DUST FROM JUPITER GOSSAMER RING
SO NATURE
LA English
DT Article
AB ONE of the most intriguing discoveries of the Ulysses mission so far has been the detection of periodic, collimated streams of high-velocity, submicrometre-sized dust particles emanating from Jupiter1,2. To explain the Ulysses data, Horanyi et al. showed3 that electromagnetic forces within Jupiter's magnetosphere can accelerate and eject small dust particles; they proposed a model in which Io is the source of the dust, and the observed periodicity arises from a resonance between the orbital and rotational periods of Io and Jupiter respectively. Here we argue that the masses and velocities of the detected particles are better explained by an origin in Jupiter's gossamer ring. Following their ejection from the magnetosphere, the dust particles are accelerated by the interplanetary magnetic field (IMF). We find that it is the temporal evolution of the IMF which primarily determines the particle trajectories, and hence which particles reach the spacecraft. Our model explains three main features observed in the Ulysses data: fewer streams are detected before closest approach than after, the observed periodicity is closely related to the solar rotation period, and an extremely intense dust stream is detected immediately after closest approach.
C1 CORNELL UNIV,DEPT THEORET & APPL MECH,ITHACA,NY 14853.
C3 Cornell University
RP HAMILTON, DP (corresponding author), CORNELL UNIV,DEPT ASTRON,ITHACA,NY 14853, USA.
NR 18
TC 64
Z9 67
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 695
EP 699
DI 10.1038/364695a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700049
DA 2026-03-10
ER

PT J
AU SAKAGUCHI, T
   BURGESS, JG
   MATSUNAGA, T
AF SAKAGUCHI, T
   BURGESS, JG
   MATSUNAGA, T
TI MAGNETITE FORMATION BY A SULFATE-REDUCING BACTERIUM
SO NATURE
LA English
DT Article
ID aquaspirillum-magnetotacticum; marine-sediments; sp-nov; iron; biomineralization; culture; deep; well; oil; dna
AB BACTERIAL production of magnetite (Fe3O4)1 makes an important contribution to iron biomineralization and remanent magnetization of sediments2,3.  Accurate magnetostratigraphy, reconstruction of the Earth's past magnetic-field behaviour and extraction of environmental information from the geomagnetic record depend on an understanding of the conditions under which bacterial magnetite is formed.  In aquatic sediments, the process is thought to be restricted to a zone between the levels at which nitrate and iron reduction occur4. In sulphate-reducing habitats, deeper in the sediment, the presence of H2S reduces iron oxyhydroxides to iron sulphides5,6.  Thus magnetite would not be expected to form under such reducing conditions5,7.  We report here the isolation and pure culture of a dissimilatory sulphate-reducing bacterium, designated RS-1, which can synthesize intracellular magnetite particles. RS-1 is a freshwater anaerobe which is also capable of extracellular iron sulphide precipitation. This isolate illustrates the wider metabolic diversity of magnetic bacteria and suggests the presence of a novel mechanism of magnetic biomineralization. The discovery of such bacteria may also explain why large quantities of magnetite have been observed in sulphate-rich, oil-bearing, sedimentary deposits8-11. In addition, these results significantly enlarge the environments in which biogenic magnetite may be expected to occur and have important implications regarding the evolution of the ability to synthesize magnetite.
C1 TOKYO UNIV AGR & TECHNOL,DEPT BIOTECHNOL,KOGANEI,TOKYO 184,JAPAN.
C3 Tokyo University of Agriculture & Technology
NR 36
TC 183
Z9 209
U1 0
U2 59
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 47
EP 49
DI 10.1038/365047a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600050
DA 2026-03-10
ER

PT J
AU CHAPARRO, A
   STROMEYER, CF
   HUANG, EP
   KRONAUER, RE
   ESKEW, RT
AF CHAPARRO, A
   STROMEYER, CF
   HUANG, EP
   KRONAUER, RE
   ESKEW, RT
TI COLOR IS WHAT THE EYE SEES BEST
SO NATURE
LA English
DT Article
ID retinal ganglion-cells; lateral geniculate-nucleus; red-green; chromatic stimuli; macaque; luminance; contrast; sensitivity; integration; adaptation
AB IT has been argued by Watson, Barlow and Robson1 that the visual stimulus that humans detect best specifies the spatial-temporal structure of the receptive field of the most sensitive visual neurons. To investigate 'what the eye sees best' they used stimuli that varied in luminance alone. Because the most abundant primate retinal ganglion cells, the P cells, are colour-opponent2-4, we might expect that a coloured pattern would also be detected well. We generalized Watson et al.'s study1 to include variations in colour as well as luminance. We report here that our best detected coloured stimulus was seen 5-9-fold better than our best luminance spot and 3-8-fold better than Watson's best luminance stimulus. The high sensitivity to colour is consistent with the prevalence and high colour contrast-gain of retinal P cells, and may compensate for the low chromatic contrasts typically found in natural scenes.
C1 HARVARD UNIV,DEPT PSYCHOL,CAMBRIDGE,MA 02138.
   NORTHEASTERN UNIV,DEPT PSYCHOL,BOSTON,MA 02115.
C3 Harvard University; Northeastern University
RP CHAPARRO, A (corresponding author), HARVARD UNIV,DIV APPL SCI,CAMBRIDGE,MA 02138, USA.
NR 28
TC 132
Z9 148
U1 1
U2 16
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 348
EP 350
DI 10.1038/361348a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000056
PM 8426653
DA 2026-03-10
ER

PT J
AU DAUTEUIL, O
   BRUN, JP
AF DAUTEUIL, O
   BRUN, JP
TI OBLIQUE RIFTING IN A SLOW-SPREADING RIDGE
SO NATURE
LA English
DT Article
ID norwegian-greenland sea; evolution; basin
AB IN oceanic rifts, the spreading direction is usually nearly perpendicular to the ridge axis, but at the Reykjanes1 and Mohns2-4 ridges this direction is highly oblique (30-degrees to 40-degrees to the axis). These ridges possess axial valleys containing oblique raised features (highs), corresponding to second- or third-order ridge axis discontinuities5. At the Reykjanes ridge, Searle and Laughton1 observed small highs which they interpreted as volcanic domes. Here we present a fault map of the Mohns ridge obtained from image processing of Seabeam data. We argue that the oblique highs in this ridge are of tectonic origin. The axial valley is interpreted as the surface trace of a deformable band of oceanic lithosphere inherited from an earlier stage of perpendicular spreading. We describe laboratory experiments on brittle-ductile models which support this interpretation, in which stretching at 30-degrees to a deformable band reproduces the en echelon horst-and-graben pattern of the Mohns ridge.
RP DAUTEUIL, O (corresponding author), GEOSCI RENNES,TECTON LAB,CAMPUS BEAULIEU,AVE GEN LECLERC,F-35042 RENNES,FRANCE.
NR 13
TC 119
Z9 128
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 145
EP 148
DI 10.1038/361145a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600056
DA 2026-03-10
ER

PT J
AU HERBST, CA
   COOK, RL
   KING, HE
AF HERBST, CA
   COOK, RL
   KING, HE
TI HIGH-PRESSURE VISCOSITY OF GLYCEROL MEASURED BY CENTRIFUGAL-FORCE VISCOMETRY
SO NATURE
LA English
DT Article
ID temperature; dependence; liquids; polymers; volume; solids; model
AB As a liquid approaches its glass transition temperature T(g), its viscosity increases rapidly. The glass transition can be induced either by lowering the temperature through T(g) or by increasing the pressure (and thereby the density) at constant temperature. The effect of temperature on viscosity is well studied, but the density dependence of viscosity close to T(g) is less well understood. Here we report measurements of the viscosity of glycerol, one of the most widely studied glass-forming liquids, at pressures of up to 3 GPa using centrifugal-force viscometry in a diamond-anvil cell. We find that free-volume theory1,2, which ascribes an incompressible hard-sphere volume to the molecules, provides a good description of the viscosity over the entire pressure range (and by extrapolation, up to the glass transition at approximately 5 GPa). We are thus able to predict the effect of pressure on T(g) and on the glass fragility (the structural breakdown in the liquid close to the transition).
RP HERBST, CA (corresponding author), EXXON RES & ENGN CO,CORP RES SCI LABS,ROUTE 22 E CLINTON TOWNSHIP,ANNANDALE,NJ 08801, USA.
NR 32
TC 64
Z9 67
U1 1
U2 45
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 518
EP 520
DI 10.1038/361518a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400053
DA 2026-03-10
ER

PT J
AU SWARTZ, KJ
   MERRITT, A
   BEAN, BP
   LOVINGER, DM
AF SWARTZ, KJ
   MERRITT, A
   BEAN, BP
   LOVINGER, DM
TI PROTEIN-KINASE-C MODULATES GLUTAMATE RECEPTOR INHIBITION OF CA2+ CHANNELS AND SYNAPTIC TRANSMISSION
SO NATURE
LA English
DT Article
ID omega-conotoxin; hippocampal-neurons; peripheral neurons; calcium channels; phorbol esters; rat; desensitization; phosphorylates; transmitter; excitation
AB FAST synaptic transmission in the central nervous system can be modulated by neurotransmitters and second-messenger pathways. For example, transmission at glutamatergic synapses can be depressed by the metabotropic glutamate receptor1,2, providing autoreceptor-mediated negative feedback. Metabotropic glutamate receptor inhibition of Ca2+ channels may contribute to this pathway3-6. In contrast, stimulation of protein kinase C can enhance excitatory synaptic transmission7, whereas both depression and enhancement of Ca2+ current have been reported8. Here we show that in hippocampal CA3 and cortical pyramidal neurons, activation of protein kinase C enhances current through N-type Ca2+ channels and, in addition, dramatically reduces G protein-dependent inhibition of these same channels by the metabotropic glutamate receptor. In parallel experiments on fast excitatory transmission at corticostriatal synapses, kinase C activators were similarly found to reduce the inhibitory effect produced by stimulation of the metabotropic glutamate receptor. The results show that second-to-second control of Ca2+ channels by the metabotropic glutamate receptor can itself be modulated on a slower timescale by protein kinase C. These mechanisms may be used in the control of fast excitatory synaptic transmission.
C1 VANDERBILT UNIV,MED CTR,SCH MED,DEPT MOLEC PHYSIOL & BIOPHYS,NASHVILLE,TN 37232.
C3 Vanderbilt University
RP SWARTZ, KJ (corresponding author), HARVARD UNIV,SCH MED,DEPT NEUROBIOL,BOSTON,MA 02115, USA.
NR 35
TC 195
Z9 212
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 165
EP 168
DI 10.1038/361165a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600063
PM 8380626
DA 2026-03-10
ER

PT J
AU BARR, TL
   KLINOWSKI, J
   HE, HY
   ALBERTI, K
   MULLER, G
   LERCHER, JA
AF BARR, TL
   KLINOWSKI, J
   HE, HY
   ALBERTI, K
   MULLER, G
   LERCHER, JA
TI EVIDENCE FOR STRONG ACIDITY OF THE MOLECULAR-SIEVE CLOVERITE
SO NATURE
LA English
DT Article
ID ray photoelectron-spectroscopy; oxides; chemistry; zeolites; esca
AB ZEOLITES derive their catalytic activity from the strong acidity of protons attached to the negatively charged aluminosilicate framework, which makes the materials excellent proton donors. Unlike zeolites, the aluminophosphate molecular sieves1,2 are built from alternating AlO4- and PO4+ tetrahedra and are thus electrically neutral. Much attention has therefore been devoted to the generation of Bronsted acidity in these materials by introducing heteroatoms, such as Si, Mg, Fe, Co or Zn, to produce negatively charged frameworks3-6. Similar arguments apply to gallophosphate molecular sieves7-10, of which cloverite9,10 is a remarkable example. This extra-large-pore material contains pore openings in the form of a four-leafed clover, defined by a ring of 20 gallium and phosphorus atoms, some of which are linked to terminal hydroxyl groups. Here we use NMR, X-rav photoelectron spectroscopy (ESCA) and infrared spectroscopy to show that the P-OH groups in cloverite are localized versions of those in solid phosphoric acid, H3PO4. Cloverite is thus a strong Bronsted acid even though no heteroatoms are present in its framework.
C1 UNIV CAMBRIDGE,DEPT CHEM,LENSFIELD RD,CAMBRIDGE CB2 1EW,ENGLAND.
   VIENNA TECH UNIV,INST PHYS CHEM,A-1060 VIENNA,AUSTRIA.
   VIENNA TECH UNIV,CHRISTIAN DOPPLER LAB HETEROGENE KATALYSE,A-1060 VIENNA,AUSTRIA.
C3 University of Cambridge; Technische Universitat Wien; Technische Universitat Wien
NR 25
TC 37
Z9 39
U1 0
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 429
EP 431
DI 10.1038/365429a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300052
DA 2026-03-10
ER

PT J
AU RODHAM, DA
   SUZUKI, S
   SUENRAM, RD
   LOVAS, FJ
   DASGUPTA, S
   GODDARD, WA III
   BLAKE, GA
AF RODHAM, DA
   SUZUKI, S
   SUENRAM, RD
   LOVAS, FJ
   DASGUPTA, S
   GODDARD, WA III
   BLAKE, GA
TI HYDROGEN-BONDING IN THE BENZENE AMMONIA DIMER
SO NATURE
LA English
DT Article
ID rotational spectrum; clusters; spectroscopy; complexes
AB AMINES have long been characterized as amphoteric (acting as both donor and acceptor) in terms of their hydrogen-bond interactions in the condensed phase. With the possible exception of (NH3)2, however, no gas-phase complexes exhibiting hydrogen-bond donation by ammonia, the 'simplest amine', have been observed1,2. Here we present high-resolution optical and microwave spectra of the benzene-ammonia dimer in the gas phase, which show that the ammonia molecule resides above the benzene plane and undergoes free or nearly free internal rotation. In the vibrationally averaged structure, the C3 symmetry axis of NH3 is tilted by about 58-degrees relative to the benzene C6 axis, such that the ammonia protons interact with the benzene tau-cloud. Our ab initio calculations predict a ''monodentate' minimum-energy structure, with very low barriers to rotation of ammonia. The larger separation of the two molecular components, and the smaller dissociation energy, relative to the benzene-water dimer3 reflect the weak hydrogen-bond donor capability of ammonia, but the observed geometry greatly resembles the amino-aromatic interaction found naturally in proteins4.
C1 NATL INST STAND & TECHNOL, DIV MOLEC PHYS, GAITHERSBURG, MD 20899 USA.
   CALTECH, BECKMAN INST,CTR MAT & MOLEC SIMULAT, PASADENA, CA 91125 USA.
   CALTECH, DIV GEOL & PLANETARY SCI, PASADENA, CA 91125 USA.
C3 National Institute of Standards & Technology (NIST) - USA; California Institute of Technology; California Institute of Technology
RP RODHAM, DA (corresponding author), CALTECH, DIV CHEM & CHEM ENGN, 127-72, PASADENA, CA 91125 USA.
NR 19
TC 269
Z9 286
U1 0
U2 75
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 735
EP 737
DI 10.1038/362735a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000050
DA 2026-03-10
ER

PT J
AU YUSE, A
   SANO, M
AF YUSE, A
   SANO, M
TI TRANSITION BETWEEN CRACK PATTERNS IN QUENCHED GLASS PLATES
SO NATURE
LA English
DT Article
ID dynamic fracture
AB THE study of fracture is an old topic1, but only recently has an understanding begun to emerge of crack formation, propagation and morphology (which is often fractal)2-8. When a brittle material such as glass is broken under tensile stress9, the cracks have a complicated morphology10. Fineberg et al.11 showed that this process may be caused by a dynamic instability, whereby the speed of crack propagation increases until it approaches the speed of sound: at this point, complex structures appear. But crack morphology in quasi-static fracture, where the speed of the crack tip is much smaller than the speed of sound, can also exhibit marked changes12. Here we present studies of crack propagation in glass plates caused by sudden but carefully controlled cooling. We observe a transition from straight to regular, wavy cracks as the tip speed increases. The scaling behaviour of an appropriately defined relaxation time suggests that this transition is a Hopf bifurcation13, like those seen in a variety of other nonlinear systems. At still higher speeds, the oscillatory cracks split into first two and then four or more branches.
RP YUSE, A (corresponding author), TOHOKU UNIV,ELECT COMMUN RES INST,SENDAI,MIYAGI 980,JAPAN.
NR 17
TC 222
Z9 239
U1 0
U2 84
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 329
EP 331
DI 10.1038/362329a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600054
PM 29633994
DA 2026-03-10
ER

PT J
AU ILDEFONSE, B
   NICOLAS, A
   BOUDIER, F
AF ILDEFONSE, B
   NICOLAS, A
   BOUDIER, F
TI EVIDENCE FROM THE OMAN OPHIOLITE FOR SUDDEN STRESS CHANGES DURING MELT INJECTION AT OCEANIC SPREADING CENTERS
SO NATURE
LA English
DT Article
ID iceland; mantle; dikes; flow
AB THE system of dikes in the uppermost mantle below oceanic spreading centres bears witness to the processes involved in the supply of melt to the ridge. Such systems cannot be studied on currently active ridges, but can be seen in ophiolites; in particular, the Oman ophiolite allows us to examine segments of a fast-spreading ridge1. Here we present a statistical analysis of the orientation of intrusions in the uppermost mantle section of the Oman ophiolite spreading centres, which points to the existence of two systems: dikes whose azimuth is parallel to the sheeted dikes (which we thus consider as related to the extensional lithospheric stress field) and sills, roughly parallel to the Moho2. Branching contemporaneous dikes and sills are frequently observed. We suggest that these relations can be explained by repeated sudden changes of the dominant stress field from lithospheric to asthenospheric. Such changes could result from the episodic relaxation of lithospheric stress in response to tension fracturing of the lithospheric lid, related to sudden melt surges. This episodic behaviour is recorded in the sheeted dike complex, with each dike (each about one metre wide) representing one of these fractures.
RP ILDEFONSE, B (corresponding author), UNIV MONTPELLIER 2,CNRS,TECTONOPHYS LAB,F-34095 MONTPELLIER 05,FRANCE.
NR 12
TC 33
Z9 34
U1 0
U2 7
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 673
EP 675
DI 
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500065
DA 2026-03-10
ER

PT J
AU TZEDAKIS, PC
AF TZEDAKIS, PC
TI LONG-TERM TREE POPULATIONS IN NORTHWEST GREECE THROUGH MULTIPLE QUATERNARY CLIMATIC CYCLES
SO NATURE
LA English
DT Article
ID vegetational history; middle pleistocene; palynology; macedonia
AB THE emergent view of Quaternary cold stage European landscapes dominated by open vegetation communities has led to the concept that tree populations occurred only in restricted sites (refugia) in southern Europe1-5, although there is still considerable uncertainty over the precise location and extent of such populations. Trees respond to Quaternary climatic change by spreading from refugia during interglacials, but at the end of an interglacial period there is no reverse migratory movement in the direction of refugia, as most northern populations degrade in situ. It has thus been proposed that survival of European trees through Quaternary climatic cycles is dependent on populations persisting continuously in southern Europe6. According to this model, it is these southern populations that furnish European interglacial forests with essentially the same components during the Quaternary and, moreover, it is failure to survive in these 'long-term refugia' that brings about a tree species' ultimate disappearance from Europe6. I present here a 430,000-year record of vegetational and climatic change from northwest Greece comparable to that of other long sequences, but exceptional in documenting the continuous presence of temperate tree pollen throughout the sequence. The levels and consistency of representation suggest the local occurrence of tree populations at fluctuating densities and distributions according to prevailing climatic regimes.
RP TZEDAKIS, PC (corresponding author), UNIV CAMBRIDGE,DEPT PLANT SCI,SUBDEPT QUATERNARY RES,DOWNING ST,CAMBRIDGE CB2 3EA,ENGLAND.
NR 36
TC 224
Z9 235
U1 1
U2 26
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 29
PY 1993
VL 364
IS 6436
BP 437
EP 440
DI 10.1038/364437a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LP640
UT WOS:A1993LP64000052
DA 2026-03-10
ER

PT J
AU ABERG, A
   NORDLUND, P
   EKLUND, H
AF ABERG, A
   NORDLUND, P
   EKLUND, H
TI UNUSUAL CLUSTERING OF CARBOXYL SIDE-CHAINS IN THE CORE OF IRON-FREE RIBONUCLEOTIDE REDUCTASE
SO NATURE
LA English
DT Article
ID concanavalin-a
AB THE principal driving forces of protein folding are the burial of hydrophobic residues in the interior of proteins and the exposure of charged residues at the surface1. Charged residues are only occasionally found in the interior, where they form hydrogen bonds to oppositely charged residues or main-chain atoms2. Ribonucleotide reductase, a key enzyme in DNA synthesis, catalyses the de novo production of deoxyribonucleotide precursors. It is composed of two different dimeric proteins R1 and R2 (refs 3-5). R2 subunits contain buried iron-centres with each centre formed by two ferric ions coordinated by four carboxylates and two histidine ligands6. Iron-free R2, apoR2, is a precursor of active R2 and folds into a stable protein which is transformed into active R2 by ferrous ions and molecular oxygen. Here we show that the iron-free protein does not undergo any major structural changes compared with the iron-containing R2. The effect of this is a clustering of four carboxyl side chains in the interior of the subunit, in contrast to the normal distribution of charged residues in proteins.
C1 LAB MOLEC BIOPHYS, OXFORD OX1 3QH, ENGLAND.
   SWEDISH UNIV AGR SCI, CTR BIOMED, DEPT MOLEC BIOL, S-75124 UPPSALA, SWEDEN.
C3 University of Oxford; Swedish University of Agricultural Sciences
RP ABERG, A (corresponding author), UNIV STOCKHOLM, DEPT MOLEC BIOL, S-10691 STOCKHOLM, SWEDEN.
NR 25
TC 69
Z9 76
U1 0
U2 9
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 276
EP 278
DI 10.1038/361276a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400066
PM 8423856
DA 2026-03-10
ER

PT J
AU MUELLER, MW
   ALLMAIER, M
   ESKES, R
   SCHWEYEN, RJ
AF MUELLER, MW
   ALLMAIER, M
   ESKES, R
   SCHWEYEN, RJ
TI TRANSPOSITION OF GROUP-II INTRON AL1 IN YEAST AND INVASION OF MITOCHONDRIAL GENES AT NEW LOCATIONS
SO NATURE
LA English
DT Article
ID nuclear genes; rna; tetrahymena; podospora; deletion; maturase; mobility; invitro; origin; dna
AB INTRON mobility at the RNA level1-8 by splicing reversal at allelic (homing) and non-allelic locations (transposition) has been reported in vitro9-12. In the living cell, however, only intron homing by unidirectional gene conversion has been described5,6,13,14. Supposing that intron insertions at non-allelic sites might occur in vivo, we speculated that group II splice-site-associated macro-deletions15-18 in fungal mitochondrial DNA might result from group II intron transposition to new locations followed by recombination. We used polymerase chain reaction techniques to detect this critical, infrequent intermediate in mtDNA populations. Here we report on group II intron aI1 transposition to non-allelic, splicing-compatible locations within the cox1 gene of yeast mtDNA. The identified integration sites are preceded by motifs similar to the upstream exon A1. Sequences flanking intron aI1 are not co-converted to the insertion sites and cis- and trans-acting mutations within aI1 reduce intron mobility below detection levels. These findings suggest the involvement of an RNA intermediate in group II intron transposition.
RP MUELLER, MW (corresponding author), UNIV VIENNA,INST MICROBIOL & GENET,VIENNA BIOCTR,A-1030 VIENNA,AUSTRIA.
NR 30
TC 84
Z9 89
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 174
EP 176
DI 10.1038/366174a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600062
PM 8232557
DA 2026-03-10
ER

PT J
AU HAY, JC
   MARTIN, TFJ
AF HAY, JC
   MARTIN, TFJ
TI PHOSPHATIDYLINOSITOL TRANSFER PROTEIN REQUIRED FOR ATP-DEPENDENT PRIMING OF CA2+-ACTIVATED SECRETION
SO NATURE
LA English
DT Article
AB ELUCIDATION of the reactions responsible for the calcium-regulated fusion of secretory granules with the plasma membrane in secretory cells would be facilitated by the identification of participant proteins having known biochemical activities. The successful characterization of cytosolic1-3 and vesicle 4,5 proteins that may function in calcium-regulated secretion has not yet revealed the molecular events underlying this process. Regulated secretion consists of sequential priming and triggering steps which depend on ATP and Ca2+, respectively, and require distinct cytosolic proteins6. Characterization of priming-specific factors (PEP proteins) should enable the ATP-requiring reactions to be identified. Here we show that one of the mammalian priming factors (PEP3) is identical to phosphatidylinositol transfer protein (PITP)7. The physiological role of PITP was previously unknown. We also find that SEC14p, the yeast phosphatidylinositol transfer protein which is essential for constitutive secretion8-10, can substitute for PEP3/PITP in priming. Our results indicate that a role for phospholipid transfer proteins is conserved in the constitutive and regulated secretory pathways.
C1 UNIV WISCONSIN, PROGRAM CELL & MOLEC BIOL, 1117 W JOHNSON ST, MADISON, WI 53706 USA.
   UNIV WISCONSIN, DEPT ZOOL, MADISON, WI 53706 USA.
C3 University of Wisconsin System; University of Wisconsin Madison; University of Wisconsin System; University of Wisconsin Madison
NR 30
TC 319
Z9 357
U1 0
U2 4
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 572
EP 575
DI 10.1038/366572a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800072
PM 8255295
DA 2026-03-10
ER

PT J
AU CLASS, C
   GOLDSTEIN, SL
   GALER, SJG
   WEIS, D
AF CLASS, C
   GOLDSTEIN, SL
   GALER, SJG
   WEIS, D
TI YOUNG FORMATION AGE OF A MANTLE PLUME SOURCE
SO NATURE
LA English
DT Article
ID lower continental-crust; south indian-ocean; isotopic composition; kerguelen plateau; evolution; basalts; convection; pb; island; constraints
AB The Ninetyeast Ridge hotspot track displays strontium, neodymium and lead isotope variations over time that reflect simple radioactive decay in the plume source rather than a change in the mantle components present. The lead isotope variations indicate that the time spent by the plume source in a non-convecting mantle boundary layer was only a few hundreds of millions of years, contrary to the conventional view of individual plume sources as old (1-3 Gyr) or persistent features.
C1 UNIV LIBRE BRUXELLES, B-1050 BRUSSELS, BELGIUM.
C3 Universite Libre de Bruxelles
RP CLASS, C (corresponding author), MAX PLANCK INST CHEM, POSTFACH 3060, W-6500 MAINZ, GERMANY.
NR 60
TC 47
Z9 47
U1 0
U2 7
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD APR 22
PY 1993
VL 362
IS 6422
BP 715
EP 721
DI 10.1038/362715a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KY450
UT WOS:A1993KY45000045
DA 2026-03-10
ER

PT J
AU HAN, M
   GOLDEN, A
   HAN, YM
   STERNBERG, PW
AF HAN, M
   GOLDEN, A
   HAN, YM
   STERNBERG, PW
TI C-ELEGANS LIN-45 RAF GENE PARTICIPATES IN LET-60 RAS-STIMULATED VULVAR DIFFERENTIATION
SO NATURE
LA English
DT Article
ID nematode caenorhabditis-elegans; embryonic cell lineages; protein-kinase-c; tyrosine kinase; induction; sequence; mutations; binding; fates; identification
AB Vulval differentiation in Caenorhabditis elegans is controlled by intercellular signalling mediated by a receptor tyrosine kinase and a ras gene product. The lin-45 gene encodes a homologue of the raf family of serine/threonine kinases and is necessary for vulval differentiation. The lin-45 raf gene product appears to act downstream of the ras protein in this pathway. A proto-oncogene-mediated signalling pathway may be a common feature of metazoan development.
C1 CALTECH,HOWARD HUGHES MED INST,DIV BIOL 15629,PASADENA,CA 91125.
C3 California Institute of Technology; Howard Hughes Medical Institute
RP HAN, M (corresponding author), UNIV COLORADO,DEPT MOLEC CELLULAR & DEV BIOL,BOULDER,CO 80309, USA.
FU NIGMS NIH HHS [R01 GM047869] Funding Source: Medline
NR 48
TC 228
Z9 291
U1 0
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 133
EP 140
DI 10.1038/363133a0
PG 8
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100038
PM 8483497
DA 2026-03-10
ER

PT J
AU ROEHL, H
   KIMBLE, J
AF ROEHL, H
   KIMBLE, J
TI CONTROL OF CELL FATE IN C-ELEGANS BY A GLP-1 PEPTIDE CONSISTING PRIMARILY OF ANKYRIN REPEATS
SO NATURE
LA English
DT Article
ID of-function mutations; caenorhabditis-elegans; notch-gene; lin-12; drosophila; sequences; lineages; locus
AB THE homologous proteins GLP-1 and LIN-12 are required for cell interactions during nematode development1-5. glp-1 and lin-12 are members of a gene family that includes Drosophila Notch and several vertebrate homologues6. The members of this family have a single transmembrane domain and a similar arrangement of repeated amino-acid motifs (see Fig. 1). The mechanism by which proteins in this family function is not understood. One hypothesis is that these proteins are receptors, each with an extracellular domain that binds a ligand and an intracellular domain that influences the activity of downstream cell fate regulators. Here we report that a region of the GLP-1 intracellular domain, consisting primarily of six ankyrin repeats, is sufficient to direct cell fate. The cell fate transformations seen are similar to transformations caused by gain-of-function mutations in either glp-1 or lin-12 and do not rely on endogenous lin-12 or glp-1 activity. We propose that the ankyrin repeat region of GLP-1 is responsible for controlling downstream regulators of cell fate.
C1 UNIV WISCONSIN,DEPT BIOCHEM,MADISON,WI 53706.
   UNIV WISCONSIN,MOLEC BIOL LAB,MADISON,WI 53706.
C3 University of Wisconsin System; University of Wisconsin Madison; University of Wisconsin System; University of Wisconsin Madison
RP ROEHL, H (corresponding author), UNIV WISCONSIN,DEPT GENET,MADISON,WI 53706, USA.
NR 26
TC 101
Z9 125
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 632
EP 635
DI 10.1038/364632a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100054
PM 8350921
DA 2026-03-10
ER

PT J
AU ESTEVEZ, M
   ATTISANO, L
   WRANA, JL
   ALBERT, PS
   MASSAGUE, J
   RIDDLE, DL
AF ESTEVEZ, M
   ATTISANO, L
   WRANA, JL
   ALBERT, PS
   MASSAGUE, J
   RIDDLE, DL
TI THE DAF-4 GENE ENCODES A BONE MORPHOGENETIC PROTEIN-RECEPTOR CONTROLLING C-ELEGANS DAUER LARVA DEVELOPMENT
SO NATURE
LA English
DT Article
ID nematode caenorhabditis-elegans; transforming growth-factor; serine threonine kinase; ventralizing factor; messenger-rna; family; differentiation; temperature; expression; pheromone
AB THE bone morphogenetic protein (BMP) family is a conserved group of signalling molecules within the transforming growth factor-beta (TGF-beta) superfamily1,2. This group, including the Drosophila decapentaplegic (dpp) protein and the mammalian BMPs, mediates cellular interactions and tissue differentiation during development3,4 . Here we show that a homologue of human BMPs controls a developmental switch in the life cycle of the free-living soil nematode Caenorhabditis elegans. Starvation and overcrowding induce C elegans to form a developmentally arrested, third-stage dauer larva5. The daf-4 gene, which acts to inhibit dauer larva formation and promote growth, encodes a receptor protein kinase similar to the daf-1, activin and TGF-beta receptor serine/threonine kinases. When expressed in monkey COS cells, the daf-4 receptor binds human BMP-2 and BMP-4. The daf-4 receptor is the first to be identified for any growth factor in the BMP family.
C1 UNIV MISSOURI,DIV BIOL SCI,COLUMBIA,MO 65211.
   MEM SLOAN KETTERING CANC CTR,HOWARD HUGHES MED INST,CELL BIOL & GENET PROGRAM,NEW YORK,NY 10021.
C3 University of Missouri System; University of Missouri Columbia; Memorial Sloan Kettering Cancer Center; Howard Hughes Medical Institute
RP ESTEVEZ, M (corresponding author), UNIV MISSOURI,MOLEC BIOL PROGRAM,311 TUCKER HALL,COLUMBIA,MO 65211, USA.
NR 31
TC 345
Z9 411
U1 0
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 644
EP 649
DI 10.1038/365644a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600058
PM 8413626
DA 2026-03-10
ER

PT J
AU BAKKER, TCM
AF BAKKER, TCM
TI POSITIVE GENETIC CORRELATION BETWEEN FEMALE PREFERENCE AND PREFERRED MALE ORNAMENT IN STICKLEBACKS
SO NATURE
LA English
DT Article
ID gasterosteus-aculeatus l; costly mate preferences; sexual selection; handicap principle; color patterns; evolution; choice; models; behavior; fisher
AB A NUMBER of population genetics models predict the evolution of male sexual ornaments through female choice1, but their genetic assumptions and predictions have hardly been investigated2,3. A key feature of these models is a positive genetic correlation between male ornaments and female preference for them4. Here I test this prediction at the within-population level with three-spined stickle-backs, Gasterosteus aculeatus, which show conspicuous sexual dichromatism5. Intense red males are preferred in various situations6-10, but there is great intrapopulational variation in redness both among wild-caught6,10 and among laboratory-bred males11, which is partly environmental6 and may be partly genetic12,13.  Also, females show considerable intrapopulational variation in their preference for redder males6,8,9, which is partly environmental8,9. Wild-caught, intense red males and dull males were crossed with a number of females from the same population in a full-sib/half-sib breeding design. Daughters were tested for their preference for more intensely red males, and the sons' coloration was quantified. Both traits showed genetic variation. Also the redness of the sons correlated with the preference for red of their sisters, thus the two traits show positive genetic correlation.
RP BAKKER, TCM (corresponding author), UNIV BERN,INST ZOOL,VERHALTENSOKOL ABT,WOHLENSTR 50A,CH-3032 HINTERKAPPELEN,SWITZERLAND.
NR 35
TC 205
Z9 227
U1 1
U2 64
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 20
PY 1993
VL 363
IS 6426
BP 255
EP 257
DI 10.1038/363255a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LC866
UT WOS:A1993LC86600050
DA 2026-03-10
ER

PT J
AU AHMAD, M
   CASHMORE, AR
AF AHMAD, M
   CASHMORE, AR
TI HY4 GENE OF A-THALIANA ENCODES A PROTEIN WITH CHARACTERISTICS OF A BLUE-LIGHT PHOTORECEPTOR
SO NATURE
LA English
DT Article
ID coli dna photolyase; arabidopsis-thaliana; insertion mutagenesis; hypocotyl elongation; domains
AB SPECIFIC responses to blue light are found throughout the biological kingdom. These responses-which in higher plants include phototropism, inhibition of hypocotyl elongation, and stomatal opening1-are in many cases thought to be mediated by flavin-type photoreceptors2. But no such blue-light photoreceptor has yet been identified or isolated, although blue-light responses in plants were reported by Darwin over a century ago3, long before the discovery of the now relatively well characterized red/far-red light photoreceptor, phytochrome. Here we describe the isolation of a gene corresponding to the HY4 locus of Arabidopsis thaliana. The hy4 mutant5 is one of several mutants6 that are selectively insensitive to blue light during the blue-light-dependent inhibition of hypocotyl elongation response, which suggests that they lack an essential component   of the cryptochrome-associated light-sensing pathway. The HY4 gene, isolated by gene tagging, was shown to encode a protein with significant homology to microbial DNA photolyases. As photolyases are a rare class of flavoprotein that catalyse blue-light-dependent reactions7, the protein encoded by HY4 has a structure consistent with that of a flavin-type blue-light photoreceptor.
RP AHMAD, M (corresponding author), UNIV PENN,INST PLANT SCI,DEPT BIOL,PHILADELPHIA,PA 19104, USA.
NR 23
TC 1070
Z9 1228
U1 2
U2 229
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 162
EP 166
DI 10.1038/366162a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600059
PM 8232555
DA 2026-03-10
ER

PT J
AU GULYAS, AI
   MILES, R
   SIK, A
   TOTH, K
   TAMAMAKI, N
   FREUND, TF
AF GULYAS, AI
   MILES, R
   SIK, A
   TOTH, K
   TAMAMAKI, N
   FREUND, TF
TI HIPPOCAMPAL PYRAMIDAL CELLS EXCITE INHIBITORY NEURONS THROUGH A SINGLE RELEASE SITE
SO NATURE
LA English
DT Article
ID miniature synaptic currents; long-term potentiation; protein parvalbumin; rat hippocampus; slices; cortex; identification; transmission; variability; system
AB MORPHOLOGICALLY a synapse consists of a presynaptic release site containing vesicles, a postsynaptic element with membrane specialization, and a synaptic cleft between them1. The number of release sites shapes the properties of synaptic transmission between neurons2-4. Although excitatory interactions between cortical neurons have been examined5-9, the number of release sites remains unknown. We have now recorded excitatory postsynaptic potentials evoked by single pyramidal cells in hippocampal interneurons and visualized both cells using biocytin injections. Light and electron microscopy showed that excitatory postsynaptic potentials were mediated by a single synapse. We also reconstructed the entire axon arborization of single pyramidal cells, filled in vivo, in sections counterstained for parvalbumin, which selectively marks basket and axo-axonic cells10,11. Single synaptic contacts between pyramidal cells and parvalbumin-containing neurons were dominant (>80%), providing evidence for high convergence and divergence in hippocampal networks12.
C1 HUNGARIAN ACAD SCI,INST EXPTL MED,POB 67,H-1450 BUDAPEST,HUNGARY.
   INST PASTEUR,INSERM,U261,NEUROBIOL LAB,F-75264 PARIS 15,FRANCE.
   FUKUI MED SCH,DEPT ANAT,FUKUI 91011,JAPAN.
C3 HUN-REN; HUN-REN Institute of Experimental Medicine; Hungarian Academy of Sciences; Institut National de la Sante et de la Recherche Medicale (Inserm); Pasteur Network; Universite Paris Cite; Institut Pasteur Paris; University of Fukui
NR 31
TC 291
Z9 312
U1 1
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 683
EP 687
DI 10.1038/366683a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500069
PM 8259211
DA 2026-03-10
ER

PT J
AU SAGER, WW
   HAN, HC
AF SAGER, WW
   HAN, HC
TI RAPID FORMATION OF THE SHATSKY RISE OCEANIC PLATEAU INFERRED FROM ITS MAGNETIC ANOMALY
SO NATURE
LA English
DT Article
ID flood basalts; pacific-ocean; seamounts; evolution
AB SHATSKY Rise, in the northwest Pacific Ocean, is probably the oldest extant oceanic plateau, and as with most such features, its origin is uncertain. Both oceanic plateaus and continental flood basalts are thought to be formed by rapid, voluminous eruptions that occur when the 'head' of a newly born mantle plume ascends to the base of the lithosphere1-3. High eruption rates have been estimated for flood basalts (for example, 1.5 km3 yr-1 for the Deccan Traps2) from dating of lava flows, but the inaccessibility of oceanic plateaus makes it necessary to extrapolate dating information from a small number of samples and sites4. Here we estimate the eruption rate of Shatsky Rise by a method that is indirect, but has the virtue of 'sampling' the entire volume of the plateau above the surrounding sea floor. The main, southern part of the plateau has a positive magnetic anomaly, corresponding to a reversed geomagnetic polarity at the time of eruption. Using age constraints to identify the longest period of reversed polarity during which the plateau could have formed, we estimate that 2 x 10(6) km3 of material erupted at a minimum rate of 1.7 km3 yr-1. This is somewhat less than the rate of 8-22 km3 yr-1 estimated for the Ontong-Java Plateau4, but still represents a massive eruption, consistent with the plume-head hypothesis.
C1 TEXAS A&M UNIV SYST,DEPT GEOPHYS,COLL STN,TX 77843.
C3 Texas A&M University System; Texas A&M University College Station
RP SAGER, WW (corresponding author), TEXAS A&M UNIV SYST,DEPT OCEANOG,COLL STN,TX 77843, USA.
NR 23
TC 58
Z9 69
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 610
EP 613
DI 10.1038/364610a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100047
DA 2026-03-10
ER

PT J
AU STEHLE, JH
   FOULKES, NS
   MOLINA, CA
   SIMONNEAUX, V
   PEVET, P
   SASSONECORSI, P
AF STEHLE, JH
   FOULKES, NS
   MOLINA, CA
   SIMONNEAUX, V
   PEVET, P
   SASSONECORSI, P
TI ADRENERGIC SIGNALS DIRECT RHYTHMIC EXPRESSION OF TRANSCRIPTIONAL REPRESSOR CREM IN THE PINEAL-GLAND
SO NATURE
LA English
DT Article
ID melatonin; gene; rat; antagonist; activator; receptor; hamster
AB Transcription factor CREM appears to play a key physiological and developmental role within the hypothalamic-pituitary-gonadal axis. This axis is modulated by the pineal hormone melatonin, whose production is in turn driven by the endogenous clock. There is striking circadian fluctuation of a novel CREM isoform, ICER, which is expressed at high levels during the night. ICER is generated from an alternative, intronic promoter and functions as a powerful repressor of cyclic AMP-induced transcription. Rhythmic adrenergic signals originated by the clock direct ICER expression by stimulation of the cAMP signal transduction pathway.
C1 FAC MED STRASBOURG, CNRS,GENET MOLEC EUCARYOTES LAB,INSERM,U184, 11 RUE HUMANN, F-67085 STRASBOURG, FRANCE.
   UNIV STRASBOURG 1, CNRS, URA 1332, F-67070 STRASBOURG, FRANCE.
C3 Centre National de la Recherche Scientifique (CNRS); Institut National de la Sante et de la Recherche Medicale (Inserm); Universites de Strasbourg Etablissements Associes; Universite de Strasbourg; Universites de Strasbourg Etablissements Associes; Universite de Strasbourg; Centre National de la Recherche Scientifique (CNRS)
NR 48
TC 379
Z9 399
U1 0
U2 5
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 314
EP 320
DI 10.1038/365314a0
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600043
PM 8397338
DA 2026-03-10
ER

PT J
AU CARNEY, HJ
   BINFORD, MW
   KOLATA, AL
   MARIN, RR
   GOLDMAN, CR
AF CARNEY, HJ
   BINFORD, MW
   KOLATA, AL
   MARIN, RR
   GOLDMAN, CR
TI NUTRIENT AND SEDIMENT RETENTION IN ANDEAN RAISED-FIELD AGRICULTURE
SO NATURE
LA English
DT Article
ID ecosystems
AB RAISED-FIELD agriculture was widespread throughout Central and South America in prehispanic times1,2. In this system of agriculture, crops are cultivated on a series of raised beds, which are separated from one another by deep, water-filled channels. In some regions, rehabilitation of the raised fields is now underway, largely because this practice leads to fertile soils, adequate water supply and protection from frost and therefore to substantially higher yields than more conventional methods3,4. Here we report analyses of water quality in the channels alongside rehabilitated raised fields in the vicinity of Tiwanaku, on the Bolivian side of the Lake Titicaca basin (Fig. 1). We find that high concentrations of nitrate, available phosphate and turbidity decline significantly as the water flows through the raised-field channels. Water flowing through control sites shows no significant change. Retention of nutrients and suspended sediments in the channels helps to maintain soil fertility and reduces pollution of down-stream waters. Thus it seems there are environmental benefits in rehabilitating raised fields, which complement and help sustain the economic benefits demonstrated previously3,4.
C1 HARVARD UNIV,GRAD SCH DESIGN,LANDSCAPE ECOL GRP,CAMBRIDGE,MA 02138.
   UNIV CHICAGO,DEPT ANTHROPOL,CHICAGO,IL 60637.
   UNIV MAYOR SAN ANDRES,INST ECOL,LA PAZ,BOLIVIA.
C3 Harvard University; University of Chicago; Universidad Mayor de San Andres
RP CARNEY, HJ (corresponding author), UNIV CALIF DAVIS,INST ECOL,DIV ENVIRONM STUDIES,DAVIS,CA 95616, USA.
NR 18
TC 21
Z9 25
U1 0
U2 24
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 131
EP 133
DI 10.1038/364131a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700043
DA 2026-03-10
ER

PT J
AU BERNHAGEN, J
   CALANDRA, T
   MITCHELL, RA
   MARTIN, SB
   TRACEY, KJ
   VOELTER, W
   MANOGUE, KR
   CERAMI, A
   BUCALA, R
AF BERNHAGEN, J
   CALANDRA, T
   MITCHELL, RA
   MARTIN, SB
   TRACEY, KJ
   VOELTER, W
   MANOGUE, KR
   CERAMI, A
   BUCALA, R
TI MIF IS A PITUITARY-DERIVED CYTOKINE THAT POTENTIATES LETHAL ENDOTOXEMIA
SO NATURE
LA English
DT Article
ID tumor-necrosis-factor; migration-inhibitory factor; activates human macrophages; binding-protein; lipopolysaccharide; cachectin; interleukin-1; hypothalamus; cells; genes
AB CYTOKINES are critical in the often fatal cascade of events that cause septic shock1-3. One regulatory system that is likely to be important in controlling inflammatory responses is the neuroendocrine axis. The pituitary, for example, is ideally situated to integrate central and peripheral stimuli4, and initiates the increase in systemic glucocorticoids that accompanies host stress responses6-8. To assess further the contribution of the pituitary to systemic inflammatory processes, we examined the secretory profile of cultured pituitary cells and whole pituitaries in vivo after stimulation with bacterial lipopolysaccharide (LPS). Here we identify macrophage migration inhibitory factor (MIF)9-11 as a major secreted protein released by anterior pituitary cells in response to LPS stimulation. Serum analysis of control, hypophysectomized and T-cell-deficient (nude) mice suggests that pituitary-derived MIF contributes to circulating MIF present in the post-acute phase of endotoxaemia. Recombinant murine MIF greatly enhances lethality when co-injected with LPS and anti-MIF antibody confers full protection against lethal endotoxaemia. We conclude that MIF plays a central role in the toxic response to endotoxaemia and possibly spetic shock.
C1 PICOWER INST MED RES,350 COMMUNITY DR,MANHASSET,NY 11030.
   UNIV TUBINGEN,INST PHYSIOL CHEM,W-7400 TUBINGEN 1,GERMANY.
   CORNELL UNIV,MED CTR,NEW YORK HOSP,COLL MED,DIV NEUROSURG,NEW YORK,NY 10021.
   N SHORE UNIV HOSP,CORNELL UNIV MED COLL,COLL MED,DEPT SURG,MANHASSET,NY 11030.
C3 Eberhard Karls University of Tubingen; Cornell University; Weill Cornell Medicine; NewYork-Presbyterian Hospital; Northwell Health; North Shore University Hospital; Cornell University
NR 27
TC 921
Z9 1023
U1 1
U2 26
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 21
PY 1993
VL 365
IS 6448
BP 756
EP 759
DI 10.1038/365756a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MC812
UT WOS:A1993MC81200064
PM 8413654
DA 2026-03-10
ER

PT J
AU GREENHAM, NC
   MORATTI, SC
   BRADLEY, DDC
   FRIEND, RH
   HOLMES, AB
AF GREENHAM, NC
   MORATTI, SC
   BRADLEY, DDC
   FRIEND, RH
   HOLMES, AB
TI EFFICIENT LIGHT-EMITTING-DIODES BASED ON POLYMERS WITH HIGH ELECTRON-AFFINITIES
SO NATURE
LA English
DT Article
ID electroluminescent diodes; carrier confinement; emission; layer
AB CONJUGATED polymers have been incorporated as active materials into several kinds of electronic device, such as diodes, transistors1 and light-emitting diodes2. The first polymer light-emitting diodes were based on poly(p-phenylene vinylene) (PPV), which is robust and has a readily processible precursor polymer. Electroluminescence in this material is achieved by injection of electrons into the conduction band and holes into the valence band, which capture one another with emission of visible radiation. Efficient injection of electrons has previously required the use of metal electrodes with low work functions, primarily calcium; but this reactive metal presents problems for device stability. Here we report the fabrication of electroluminescent devices using a new family of processible poly(cyanoterephthalylidene)s. As the lowest unoccupied orbitals of these polymers (from which the conduction band is formed) lie at lower energies than those of PPV, electrodes made from stable metals such as aluminium can be used for electron injection. For hole injection, we use indium tin oxide coated with a PPV layer; this helps to localize charge at the interface between the PPV and the new polymer, increasing the efficiency of recombination. In this way, we are able to achieve high internal efficiencies (photons emitted per electrons injected) of up to 4% in these devices.
C1 UNIV CAMBRIDGE, CHEM LAB, CAMBRIDGE CB2 1EW, ENGLAND.
C3 University of Cambridge
RP GREENHAM, NC (corresponding author), UNIV CAMBRIDGE, CAVENDISH LAB, MADINGLEY RD, CAMBRIDGE CB3 0HE, ENGLAND.
NR 22
TC 1687
Z9 1815
U1 2
U2 252
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD OCT 14
PY 1993
VL 365
IS 6447
BP 628
EP 630
DI 10.1038/365628a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MB846
UT WOS:A1993MB84600052
DA 2026-03-10
ER

PT J
AU PEREZVELAZQUEZ, JL
   ANGELIDES, KJ
AF PEREZVELAZQUEZ, JL
   ANGELIDES, KJ
TI ASSEMBLY OF GABA(A) RECEPTOR SUBUNITS DETERMINES SORTING AND LOCALIZATION IN POLARIZED CELLS
SO NATURE
LA English
DT Article
ID hippocampal-neurons; functional expression; membrane glycoprotein; epithelial-cells; messenger-rna; proteins; rat; heterogeneity; biogenesis; domains
AB THE GABA(A) receptor, the principal inhibitory receptor in the CNS, is distributed on cell bodies, dendrites, and in some cells at axon hillocks and presynaptic terminals1-6. The dendritic distribution is crucial for shunting of excitatory synaptic inputs7,8. Molecular cloning has revealed that the GABA(A) receptor can be formed by a diverse set of subunits and by separately encoded subunit isoforms9,10, the expression of each of which differs in distinct areas of the central nervous system11-13 and during development14,15. Why different genes exist to encode these isoforms is not clear, but may be linked to functional differences16-19. Here we show that assembly of specific isoforms also codes for sorting and localization of the receptor complex. Confocal microscopy and immunoblot analysis of epithelial cells transfected with the complementary DNAs encoding the alpha1 and beta1 GABA(A) receptor subunits and probed with subunit isoform-specific antibodies show that the alpha1 subunit is targeted to the basolateral surface, and that the beta1 subunit is sorted to the apical membrane. In cells where alpha1 and beta1 isoforms are co-expressed, assembly of the beta1 with the alpha1 subunit isoform re-routes the alpha1 subunit to the apical surface. The ability to assemble complexes of different isoform composition and to target these to specific regions of the cell surface would enable neurons to modulate GABA(A) receptor distribution and possibly alter the composition of its synapses in response to transcriptional levels of specific subunit isoforms.
C1 BAYLOR COLL MED,DEPT CELL BIOL,HOUSTON,TX 77030.
   BAYLOR COLL MED,DEPT BIOCHEM,HOUSTON,TX 77030.
   BAYLOR COLL MED,DEPT NEUROSCI,HOUSTON,TX 77030.
C3 Baylor College of Medicine; Baylor College of Medicine; Baylor College of Medicine
NR 43
TC 68
Z9 71
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 457
EP 460
DI 10.1038/361457a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300063
PM 8381522
DA 2026-03-10
ER

PT J
AU TAKAHASHI, T
   MOMIYAMA, A
AF TAKAHASHI, T
   MOMIYAMA, A
TI DIFFERENT TYPES OF CALCIUM CHANNELS MEDIATE CENTRAL SYNAPTIC TRANSMISSION
SO NATURE
LA English
DT Article
ID metabotropic glutamate receptor; omega-aga-iva; selective modulation; nerve-terminals; neurons; conotoxin; hippocampus; release; invitro
AB SYNAPTIC transmission is mediated by calcium entry through voltage-dependent calcium channels in presynaptic nerve terminals1,2. Various types of calcium channel have been characterized in neuronal somata3-6, but it is not clear which subtypes induce transmitter release at central synapses. The N-type Ca2+ channel blocker omega-conotoxin GVIA (omega-CgTx) suppresses the excitatory postsynaptic responses only partially7,8, whereas potassium-induced release of glutamate from brain synaptosomes can be blocked by omega-Aga-VIA (ref. 9), a blocker of P-type calcium channels5,10 and possibly of other types of calcium channels11,12. Here we test type-specific calcium-channel blockers on postsynaptic currents recorded from neurons in thin slices of rat central nervous system13. Inhibitory postsynaptic currents in cerebellar and spinal neurons and excitatory postsynaptic currents in hippocampal neurons are markedly suppressed by omega-Aga-IVA and reduced to a lesser extent by omega-CgTx. The L-type calcium channel blocker nicardipine had no effect. Our results indicate that at least two types of calcium channel mediate synaptic transmission in the mammalian central nervous system.
C1 KYOTO UNIV,FAC MED,DEPT PHYSIOL,KYOTO 606,JAPAN.
C3 Kyoto University
NR 25
TC 669
Z9 727
U1 0
U2 26
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 156
EP 158
DI 10.1038/366156a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600057
PM 7901765
DA 2026-03-10
ER

PT J
AU GURNIS, M
AF GURNIS, M
TI PHANEROZOIC MARINE INUNDATION OF CONTINENTS DRIVEN BY DYNAMIC TOPOGRAPHY ABOVE SUBDUCTING SLABS
SO NATURE
LA English
DT Article
ID scale mantle convection; sea-level changes; subsidence; platforms
AB A spherical model of mantle flow constrained by the locations of trenches can be used to predict the dynamic topography of the Earth's surface, and hence the marine inundation of continents. For past periods of high sea level, the predicted geographical pattern of flooding correlates well with the geological record. The high spatial correlation may result from increased plate velocities at these times, leading to increased rates of subduction, subsidence and inundation at convergent margins.
RP GURNIS, M (corresponding author), UNIV MICHIGAN, DEPT GEOL SCI, ANN ARBOR, MI 48109 USA.
NR 32
TC 154
Z9 171
U1 0
U2 12
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 589
EP 593
DI 10.1038/364589a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100041
DA 2026-03-10
ER

PT J
AU SERENO, PC
   FORSTER, CA
   ROGERS, RR
   MONETTA, AM
AF SERENO, PC
   FORSTER, CA
   ROGERS, RR
   MONETTA, AM
TI PRIMITIVE DINOSAUR SKELETON FROM ARGENTINA AND THE EARLY EVOLUTION OF DINOSAURIA
SO NATURE
LA English
DT Article
AB WE report here the discovery of a primitive dinosaur skeleton from Upper Triassic strata in northwestern Argentina. The 1-m-long skeleton represents a new taxon, Eoraptor lunensis gen. et sp. nov., which is close to the predicted structure and size of the common dinosaurian ancestor1-5. The skull, which has a unique heterodont dentition, does not exhibit any of the specializations of the major dinosaurian clades (Ornithischia, Sauropodomorpha, Theropoda). The forelimbs are less than half the length of the hind limbs, which suggests an obligatory bipedal posture. Although close in overall form to the common dinosaurian ancestor, the functionally tridactyl, grasping/raking hand and other features show that Eoraptor is allied phylogenetically with theropods. The discovery of Eoraptor supports the hypothesis that dinosaurs diverged rapidly at small body size from a common ancestor, with the principal herbivorous and carnivorous lineages present by the middle Carnian.
C1 UNIV NACL SAN JUAN,MUSEO CIENCIAS NAT,SAN JUAN 5400,ARGENTINA.
   UNIV CHICAGO,DEPT GEOPHYS SCI,CHICAGO,IL 60637.
C3 Universidad Nacional de San Juan; University of Chicago
RP SERENO, PC (corresponding author), UNIV CHICAGO,DEPT ORGANISMAL BIOL & ANAT,1027 E 57TH ST,CHICAGO,IL 60637, USA.
NR 24
TC 214
Z9 234
U1 1
U2 34
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 64
EP 66
DI 10.1038/361064a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800048
DA 2026-03-10
ER

PT J
AU GORDON, C
   MCGURK, G
   DILLON, P
   ROSEN, C
   HASTIE, ND
AF GORDON, C
   MCGURK, G
   DILLON, P
   ROSEN, C
   HASTIE, ND
TI DEFECTIVE MITOSIS DUE TO A MUTATION IN THE GENE FOR A FISSION YEAST 26S PROTEASE SUBUNIT
SO NATURE
LA English
DT Article
ID cyclin
AB WE have isolated a mutant, mts2, in the fission yeast Schizosaccharomyces pombe which is defective in chromosome segregation. The predicted amino-acid sequence of the cloned mts2+ gene product is 75% identical to the S4 subunit of the human 26S ATP/ubiquitin-dependent protease1. The human S4 subunit complementary DNA expressed from an S. pombe expression plasmid can rescue an S. pombe mts2 gene disruption. Both observations demonstrate that the mts2+ gene is the S. pombe homologue of the human S4 subunit. In addition, we provide genetic evidence for a physical interaction between the S4 and the related S7 subunit in the 26S multiprotein protease. We show that polyubiquitin-conjugated proteins accumulate in the mts2 mutant at the restrictive temperature, demonstrating that the mutant has an in vivo defect in the ubiquitin-dependent proteolysis pathway. Finally, the phenotype for the mts2 mutant indicates that protein degradation by the 26S protease is essential not for entry into but for the completion of mitosis.
C1 ROCHE INST MOLEC BIOL, ROCHE RES CTR, DEPT GENE REGULAT, NUTLEY, NJ 07110 USA.
   HUMAN GENOME SCI, ROCKVILLE, MD 20850 USA.
C3 Roche Holding; Roche Holding USA; GlaxoSmithKline; Glaxosmithkline USA; Human Genome Sciences Inc
RP GORDON, C (corresponding author), WESTERN GEN HOSP, MRC, HUMAN GENET UNIT, CREWE RD, EDINBURGH EH4 2XU, MIDLOTHIAN, SCOTLAND.
NR 17
TC 222
Z9 229
U1 0
U2 2
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 355
EP 357
DI 10.1038/366355a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500052
PM 8247131
DA 2026-03-10
ER

PT J
AU MURRY, RL
   STROUT, DL
   ODOM, GK
   SCUSERIA, GE
AF MURRY, RL
   STROUT, DL
   ODOM, GK
   SCUSERIA, GE
TI ROLE OF SP(3) CARBON AND 7-MEMBERED RINGS IN FULLERENE ANNEALING AND FRAGMENTATION
SO NATURE
LA English
DT Article
ID hartree-fock; c-60; buckminsterfullerene; c60
AB WHEN fullerenes1,2 are fragmented by laser irradiation, they lose C2 fragments and retain a closed carbon cage3. The detailed mechanism of this process remains unknown, although survival of the cage implies that annealing (rearrangement of the bonding) must play an important role3,4. Here we use ab initio quantum-chemical calculations to show that fullerene annealing happens more readily than fragmentation, and that both are intimately related. Our findings imply that the assumptions commonly made about fullerenes5-that they are composed of five- and six-membered rings of sp2 carbons- are not valid under high-energy conditions. In particular, the appearance of sp3 carbon and seven-membered rings is central in both the annealing and fragmentation processes. Our theoretical predictions imply that the high-energy processes of fullerene growth6-11 and coalescence12 are much richer than previously thought, and that their mechanisms may also involve structures containing sp3 carbon and seven-membered rings. Our results may aid in the design of experimental methods for controlling the nature of fullerene cages (for example, doping, opening and re-closing them).
C1 RICE UNIV, DEPT CHEM, HOUSTON, TX 77251 USA.
   RICE UNIV, RICE QUANTUM INST, HOUSTON, TX 77251 USA.
C3 Rice University; Rice University
NR 26
TC 197
Z9 210
U1 0
U2 26
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 665
EP 667
DI 10.1038/366665a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500062
DA 2026-03-10
ER

PT J
AU CASEY, WH
   WESTRICH, HR
   BANFIELD, JF
   FERRUZZI, G
   ARNOLD, GW
AF CASEY, WH
   WESTRICH, HR
   BANFIELD, JF
   FERRUZZI, G
   ARNOLD, GW
TI LEACHING AND RECONSTRUCTION AT THE SURFACES OF DISSOLVING CHAIN-SILICATE MINERALS
SO NATURE
LA English
DT Article
ID dissolution kinetics; reaction-rates; feldspar; wollastonite; hydrolysis; chrysotile; mechanism; pyroxene
AB THE pathways by which silicate minerals transform to solutes, clays and amorphous solids are relevant to a wide range of natural, industrial and even medical concerns. For example, weathered layers on silicate may have a high sorptive capacity, affecting nutrient and contamination retention in soils; less obviously, such layers on inhaled silicate grains might affect their interaction with lung tissue. Here we report the observation, in dissolution experiments on a range of chain-silicate minerals, of the formation of a near-surface amorphous region enriched in silicon and hydrogen, and depleted in other metals. Raman spectroscopy and ion-beam elemental analysis show that portions of the polymeric silicate anion in this region spontaneously reconstruct to form a network that contains four-member silicate rings and areas of incipient crystallization.  If hydrolysable metals interact with the silicate anion during this reconstruction, clays and amorphous products may form directly. This process complements traditional dissolution-precipitation pathways of mineral diagenesis1, as the silicon does not have to be present in solution before being incorporated into a growing secondary phase.
C1 UNIV CALIF DAVIS,DEPT GEOL,DAVIS,CA 95616.
   SANDIA NATL LABS,GEOCHEM RES,ALBUQUERQUE,NM 87185.
   SANDIA NATL LABS,DIV ION SOLID & INTERACT,ALBUQUERQUE,NM 87185.
   UNIV WISCONSIN,DEPT GEOL,MADISON,WI 53706.
C3 University of California System; University of California Davis; United States Department of Energy (DOE); Sandia National Laboratories; United States Department of Energy (DOE); Sandia National Laboratories; University of Wisconsin System; University of Wisconsin Madison
RP CASEY, WH (corresponding author), UNIV CALIF DAVIS,DEPT LAND AIR & WATER RESOURCES,DAVIS,CA 95616, USA.
NR 28
TC 203
Z9 219
U1 0
U2 93
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 18
PY 1993
VL 366
IS 6452
BP 253
EP 256
DI 10.1038/366253a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MH325
UT WOS:A1993MH32500059
DA 2026-03-10
ER

PT J
AU HESSLER, NA
   SHIRKE, AM
   MALINOW, R
AF HESSLER, NA
   SHIRKE, AM
   MALINOW, R
TI THE PROBABILITY OF TRANSMITTER RELEASE AT A MAMMALIAN CENTRAL SYNAPSE
SO NATURE
LA English
DT Article
ID excitatory postsynaptic potentials; group-ia synapses; time course; transmission; glutamate; receptor; currents
AB WHEN an action potential reaches a synaptic terminal, fusion of a transmitter-containing vesicle with the presynaptic membrane occurs with a probability (p(r))  of less than one1. Despite the fundamental importance of this parameter, p(r) has not been directly measured in the central nervous system. Here we describe a novel approach to determine p(r), monitoring the decrement of NMDA (N-methyl-D-aspartate)-receptor mediated synaptic currents in the presence of the use-dependent channel blocker MK-801 (ref. 2). On a single postsynaptic CA1 hippocampal slice neuron, two classes of synapses with a sixfold difference in p(r) are resolved. Synapses with low p(r) contribute to over half of transmission and are more sensitive to drugs enhancing transmitter release. Switching between these two classes of synapses provides the potential for large changes in synaptic efficacy and could underlie forms of activity-dependent plasticity.
C1 UNIV IOWA,NEUROSCI PROGRAM,IOWA CITY,IA 52242.
   UNIV IOWA,DEPT PHYSIOL & BIOPHYS,IOWA CITY,IA 52242.
C3 University of Iowa; University of Iowa
NR 20
TC 482
Z9 528
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 569
EP 572
DI 10.1038/366569a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800071
PM 7902955
DA 2026-03-10
ER

PT J
AU FORTINI, ME
   REBAY, I
   CARON, LA
   ARTAVANISTSAKONAS, S
AF FORTINI, ME
   REBAY, I
   CARON, LA
   ARTAVANISTSAKONAS, S
TI AN ACTIVATED NOTCH RECEPTOR BLOCKS CELL-FATE COMMITMENT IN THE DEVELOPING DROSOPHILA EYE
SO NATURE
LA English
DT Article
ID sevenless protein; tyrosine kinase; gene-product; locus; melanogaster; expression; homolog; photoreceptor; sequence; enhancer
AB THE Notch locus of Drosophila melanogaster encodes a 2,703-amino-acid transmembrane protein required for a variety of developmental processes, including neurogenesis, oogenesis and ommatidial assembly1,2.  The Notch protein contains a large extracellular domain of 36 epidermal growth factor-like repeats as well as three Notch/Lin-12 repeats and an intracellular domain with 6 Cdc10/ankyrin repeats, motifs that are highly conserved in several vertebrate Notch homologues3-9. Truncation of the extracellular domain of the Drosophila Notch protein produces an activated receptor, as judged by its ability to cause phenotypes similar to gain-of-function alleles or duplications of the Notch locus10. Equivalent truncations of vertebrate Notch-related proteins have been associated with malignant neoplasms and other developmental abnormalities8,11-13.  We present here an analysis of activated Notch function at single-cell resolution in the Drosophila compound eye. We find that overexpression of full-length Notch in defined cell types has no apparent effects but that overexpression of activated Notch in the same cells transiently blocks their proper cell-fate commitment, causing them either to adopt incorrect cell fates or to differentiate incompletely. Moreover, an activated Notch protein lacking the transmembrane domain is translocated to the nucleus, raising the possibility that Notch may participate directly in nuclear events.
C1 YALE UNIV,DEPT BIOL,NEW HAVEN,CT 06536.
   YALE UNIV,HOWARD HUGHES MED INST,NEW HAVEN,CT 06536.
C3 Yale University; Howard Hughes Medical Institute; Yale University
RP FORTINI, ME (corresponding author), YALE UNIV,DEPT CELL BIOL,NEW HAVEN,CT 06536, USA.
NR 30
TC 282
Z9 325
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 555
EP 557
DI 10.1038/365555a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100057
PM 8413612
DA 2026-03-10
ER

PT J
AU MILINKOVITCH, MC
   ORTI, G
   MEYER, A
AF MILINKOVITCH, MC
   ORTI, G
   MEYER, A
TI REVISED PHYLOGENY OF WHALES SUGGESTED BY MITOCHONDRIAL RIBOSOMAL DNA-SEQUENCES
SO NATURE
LA English
DT Article
ID evolution; rna; mammals; origin; eocene
AB LIVING cetaceans are subdivided into two highly distinct suborders, Odontoceti (the echolocating toothed whales) and Mysticeti (the filter-feeding baleen whales), which are believed to have had a long independent history. Here we report the determination of DNA sequences from two mitochondrial ribosomal gene segments (930 base pairs per species) for 16 species of cetaceans, a perissodactyl and a sloth, and construct the first phylogeny for whales and dolphins based on explicit cladistic methods. Our data (and earlier published myoglobin sequences) confirmed that cetaceans are closely related to artiodactyls and that all families and superfamilies of cetaceans are monophyletic. A surprising finding was that one group of toothed whales, the sperm whales, is more closely related to the baleen whales than to other odontocetes. The common ancestor of baleen whales and sperm whales might have lived only 10-15 million years ago. The suggested paraphyly of toothed whales has many implications for classification, phylogeny and our understanding of the evolutionary history of cetaceans.
C1 SUNY STONY BROOK,DEPT ECOL & EVOLUT,STONY BROOK,NY 11794.
   UNIV LIBRE BRUXELLES,INST RECH INTERDISCIPLINAIRE BIOL HUMAINE & NUCL,B-1070 BRUSSELS,BELGIUM.
C3 State University of New York (SUNY) System; Stony Brook University; Universite Libre de Bruxelles
NR 31
TC 146
Z9 161
U1 1
U2 47
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 346
EP 348
DI 10.1038/361346a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000055
PM 8426652
DA 2026-03-10
ER

PT J
AU TOMOTSUNE, D
   SHOJI, H
   WAKAMATSU, Y
   KONDOH, H
   TAKAHASHI, N
AF TOMOTSUNE, D
   SHOJI, H
   WAKAMATSU, Y
   KONDOH, H
   TAKAHASHI, N
TI A MOUSE HOMOLOG OF THE DROSOPHILA TUMOR-SUPPRESSOR GENE L(2)GL CONTROLLED BY HOX-C8 IN-VIVO
SO NATURE
LA English
DT Article
ID homeotic genes; expression; protein; ultrabithorax; organization; melanogaster; capacity; disruption; polymerase; sequence
AB THE homeobox is a 183-base-pair DNA sequence originally found in Drosophila segmentation and homeotic genes1,2. In Drosophila, homeotic genes are clustered in the Antennapedia and Bithorax complexes, collectively called the homeotic gene complex (HOM-C)3. In the mouse genome, about 40 homeobox genes (Hox) are clustered in four chromosomal regions (Hox A to D). The Hox genes are arranged in the same order and have the same antero-posterior pattern of expression as their structural homologue in the HOM-C4,5, suggesting that they control mouse pattern formation in the same way that HOM-C members do in Drosophila. Homeobox gene products are believed to be transcription factors that regulate expression of target genes. A few candidate target genes have been identified in Drosophila by various approaches6 but the Hox gene targets are poorly understood, mostly because of limitations in the available approaches. Here we identify several candidate Hox gene targets, including a mouse homologue of the Drosophila tumour-suppressor gene l(2)gl, by immunopurification of DNA sequences bound to a Hox protein in native chromatin.
C1 NAGOYA UNIV,SCH SCI,DEPT MOLEC BIOL,NAGOYA,AICHI 464,JAPAN.
C3 Nagoya University
NR 29
TC 106
Z9 114
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 69
EP 72
DI 10.1038/365069a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600056
PM 8103190
DA 2026-03-10
ER

PT J
AU HERNDL, GJ
   MULLERNIKLAS, G
   FRICK, J
AF HERNDL, GJ
   MULLERNIKLAS, G
   FRICK, J
TI MAJOR ROLE OF ULTRAVIOLET-B IN CONTROLLING BACTERIOPLANKTON GROWTH IN THE SURFACE-LAYER OF THE OCEAN
SO NATURE
LA English
DT Article
ID marine; antarctica; bacteria; carbon
AB THERE is evidence that the potentially harmful solar ultraviolet-B (UV-B, 280-320 mm) radiation penetrates much deeper into the ocean's water column than previously thought1,2. UV-B radiation is also responsible for photochemical degradation of refractory macromolecules into biologically labile organic compounds3,4. It thus seems reasonable to assume that UV-B radiation might influence the cycling of organic matter in the sea, which is believed to be largely mediated by bacterioplankton5. Here we report that bacterioplankton activity in the surface layers of the oceans is suppressed by solar radiation by about 40% in the top 5 m of the water column in nearshore waters, whereas in oligotrophic open oceans suppression might be detectable to a depth of >10 m. Bacterioplankton from near-surface (0.5 m depth) waters of a highly stratified water column were as sensitive to surface UV-B radiation as subpycnocline bacteria, indicating no adaptative mechanisms against surface solar radiation in near-surface bacterioplankton consortia. Surface solar radiation levels also photochemically degrade bacterial extracellular enzymes. Thus elevated UV-B radiation due to the destruction of the stratospheric ozone layer might lead to reduced bacterial activity and accompanying increased concentration of labile dissolved organic matter in the surface layers of the ocean as bacterial uptake of this is retarded.
RP HERNDL, GJ (corresponding author), UNIV VIENNA,INST ZOOL,ALTHANSTR 14,A-1090 VIENNA,AUSTRIA.
NR 13
TC 281
Z9 309
U1 0
U2 38
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 717
EP 719
DI 10.1038/361717a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900053
DA 2026-03-10
ER

PT J
AU GRATZ, AJ
   NELLIS, WJ
   HINSEY, NA
AF GRATZ, AJ
   NELLIS, WJ
   HINSEY, NA
TI OBSERVATIONS OF HIGH-VELOCITY, WEAKLY SHOCKED EJECTA FROM EXPERIMENTAL IMPACTS
SO NATURE
LA English
DT Article
ID antarctic meteorite; lunar origin; alha-81005; spallation
AB A SMALL proportion of meteorites found on Earth are thought to come from planet-sized bodies1,2. The 'lunar meteorites' are now well established as having come from the Moon3-6 on the basis of direct comparison with lunar samples. The SNC meteorites (shergottites, nakhlites and chassignites) - seven achondrite meteorites distinguished by extremely young formation ages (<1.3 Gyr), high volatile contents, distinctive oxygen isotopic ratios and rare earth compositions - are igneous rocks, believed2 to have formed on a planet, probably Mars. But it is hard to reconcile the weakly shocked nature of many lunar and SNC meteorites with the strong shock metamorphism known to accompany impacts of the size required to eject material from a planet-sized body. Computer modelling7-10 of impacts has yet to resolve this issue, although it has been proposed9,10 that surface rarefaction near an impact can produce high-velocity, weakly shocked ejecta. Here we present the results of a cratering experiment which separates and captures the ejecta from different regions around the impact site. We recover high-velocity, weakly shocked material as predicted9,10, lending additional support both to our understanding of cratering mechanics and to a planetary or lunar origin for the SNC and lunar meteorites.
C1 LAWRENCE LIVERMORE NATL LAB,DIV H,LIVERMORE,CA 94550.
C3 United States Department of Energy (DOE); Lawrence Livermore National Laboratory
RP GRATZ, AJ (corresponding author), LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550, USA.
NR 22
TC 28
Z9 29
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 10
PY 1993
VL 363
IS 6429
BP 522
EP 524
DI 10.1038/363522a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LF939
UT WOS:A1993LF93900041
DA 2026-03-10
ER

PT J
AU GREIG, S
   AKAM, M
AF GREIG, S
   AKAM, M
TI HOMEOTIC GENES AUTONOMOUSLY SPECIFY ONE ASPECT OF PATTERN IN THE DROSOPHILA MESODERM
SO NATURE
LA English
DT Article
ID embryos; expression; twist; gradient; protein
AB TRANSPLANTATION and ablation experiments have led to the generalization that in insects the mesoderm is naive, and that pattern is imposed upon it by the ectoderm1-6. This has been demonstrated directly by mosaic analysis for the case of one muscle in Drosophila. The unique character of this muscle depends on the activity of sex-determining and homeotic genes, not in the muscle itself, but in the nerve that innervates it7. Indirect evidence suggests, however, that homeotic genes specify some aspects of mesoderm patterning autonomously. Homeotic genes are expressed in the mesoderm, and are regulated in a segment-specific pattern analogous to, but different from, that seen in the ectoderm6,8. Moreover, the effects of homeotic mutations on the muscles do not always mirror transformations seen in the epidermis9,10. Here we examine this problem directly, by expressing homeotic genes ectopically in the mesoderm without altering their expression in the overlying ectoderm. We find that the pattern of adult muscle precursor cells characteristic of the thorax can be converted to that seen in the abdomen by expressing the homeotic gene abdominal-A specifically in the mesoderm.
C1 DEPT GENET,CAMBRIDGE CB2 1QR,ENGLAND.
RP GREIG, S (corresponding author), WELLCOME CRC INST,TENNIS COURT RD,CAMBRIDGE CB2 1QR,ENGLAND.
FU Wellcome Trust Funding Source: Medline
NR 23
TC 148
Z9 167
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 630
EP 632
DI 10.1038/362630a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800047
PM 8096627
DA 2026-03-10
ER

PT J
AU BROWNING, ND
   CHISHOLM, MF
   PENNYCOOK, SJ
AF BROWNING, ND
   CHISHOLM, MF
   PENNYCOOK, SJ
TI ATOMIC-RESOLUTION CHEMICAL-ANALYSIS USING A SCANNING-TRANSMISSION ELECTRON-MICROSCOPE
SO NATURE
LA English
DT Article
ID interface; crystals; scattering
AB THE high angle elastic scattering of electrons in scanning transmission electron microscopy depends strongly on the atomic number Z, of the sample atoms, through the Z2 dependence of the Rutherford scattering cross-section1. The detection of scattered electrons at high angles and over a large angular range (75-150 milliradians) removes the coherent effects of diffraction, and the resulting incoherent image provides a compositional map of the sample with high atomic-number contrast1. If a fine electron probe is used, and the sample is a crystalline material oriented along one of its principal axes, individual columns of atoms can be imaged in this way2. Electrons scattered at low angles are not used in this detection scheme, and are thus available for simultaneous electron energy-loss spectroscopy3; in principle, this combination of techniques should allow the direct chemical analysis of single atomic columns in crystalline materials. Here we present electron energy-loss spectra from expitaxial interfaces between cobalt silicide and silicon, which confirm that atomic resolution can be achieved by this approach. The ability to correlate structure and chemistry with atomic resolution holds great promise for the detailed study of defects and interfaces.
RP BROWNING, ND (corresponding author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA.
NR 20
TC 447
Z9 512
U1 2
U2 192
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 143
EP 146
DI 10.1038/366143a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600052
DA 2026-03-10
ER

PT J
AU HAYASHI, Y
   MOMIYAMA, A
   TAKAHASHI, T
   OHISHI, H
   OGAWAMEGURO, R
   SHIGEMOTO, R
   MIZUNO, N
   NAKANISHI, S
AF HAYASHI, Y
   MOMIYAMA, A
   TAKAHASHI, T
   OHISHI, H
   OGAWAMEGURO, R
   SHIGEMOTO, R
   MIZUNO, N
   NAKANISHI, S
TI ROLE OF A METABOTROPIC GLUTAMATE-RECEPTOR IN SYNAPTIC MODULATION IN THE ACCESSORY OLFACTORY-BULB
SO NATURE
LA English
DT Article
ID nervous-system; neurons; expression; cloning; brain
AB VARIOUS functions of glutamate transmission are mediated by both ionotropic and metabotropic glutamate receptors1. The metabotropic glutamate receptors (mGluRs) consist of at least six different subtypes that are classified into three subgroups, mGluR1/mGluR5, mGluR2/mGluR3, and mGluR4/mGluR6 (refs 1-5), but their physiological roles are largely unknown. Here we report the identification of a very potent agonist for mGluR2/mGluR3, DCG-IV, and the specific localization of mGluR2 in granule cell dendrites that form dendrodendritic synapses with mitral cells in the accessory olfactory bulb. Using the DCG-IV agonist for mGluR2 in combination with slice patch-recording, we demonstrate that the granule cell mGluR2 presynaptically suppresses inhibitory GABA (gamma-aminobutyrate) transmission to the mitral cell. Our results indicate that mGluR2 in granule cells plays an important role in the persistent excitation of olfactory sensory transmission in the accessory olfactory bulb by relieving mitral cells from the GABA inhibition.
C1 KYOTO UNIV,FAC MED,INST IMMUNOL,KYOTO 606,JAPAN.
   KYOTO UNIV,FAC MED,DEPT PHARMACOL,KYOTO 606,JAPAN.
   KYOTO UNIV,FAC MED,DEPT PHYSIOL,KYOTO 606,JAPAN.
   KYOTO UNIV,FAC MED,DEPT MORPHOL BRAIN SCI,KYOTO 606,JAPAN.
C3 Kyoto University; Kyoto University; Kyoto University; Kyoto University
NR 20
TC 351
Z9 369
U1 0
U2 10
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 687
EP 690
DI 10.1038/366687a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500070
PM 7903116
DA 2026-03-10
ER

PT J
AU BEINBORN, M
   LEE, YM
   MCBRIDE, EW
   QUINN, SM
   KOPIN, AS
AF BEINBORN, M
   LEE, YM
   MCBRIDE, EW
   QUINN, SM
   KOPIN, AS
TI A SINGLE AMINO-ACID OF THE CHOLECYSTOKININ-B GASTRIN RECEPTOR DETERMINES SPECIFICITY FOR NONPEPTIDE ANTAGONISTS
SO NATURE
LA English
DT Article
ID analgesia; l-365,260; potent
AB THE brain cholecystokinin-B/gastrin receptor (CCK-B/gastrin) has been implicated in mediating anxiety, panic attacks, satiety, and the perception of pain1-5. The canine and human CCK-B/gastrin receptors share 90% amino-acid identity6,7 and have similar agonist affinities. These receptors can be selectively blocked by the non-peptide benzodiazepine-based antagonists L365260 (ref. 8) and L364718 (ref. 9); however, the binding of these antagonists to the human and canine receptors differs by up to 20-fold, resulting in a reversal of affinity rank order. Here we report the identification of a single amino acid in the sixth transmembrane domain of the CCK-B/gastrin receptor that corresponds to valine 319 in the human homologue and which is critical in determining the binding affinity for these non-peptide antagonists. We show that it is the variability in the aliphatic side chain of the amino acid in position 319 that confers antagonist specificity. Substitution of valine 319 with a leucine residue decreases the affinity for L365260 20-fold while concomitantly increasing the affinity for L364718. An isoleucine in the same position of the human receptor selectively increases affinity for L364718. Interspecies differences in the aliphatic amino acid occupying this single position selectively affect antagonist affinities without altering the agonist binding profile6,7,10. We therefore conclude that the residues underlying non-peptide antagonist affinity must differ from those that confer agonist specificity. To our knowledge, these findings are the first example in which a critical antagonist binding determinant for a seven-transmembrane-domain peptide hormone receptor has been identified.
C1 TUFTS UNIV,NEW ENGLAND MED CTR,SCH MED,DIV GASTROENTEROL,BOSTON,MA 02111.
   TUFTS UNIV,NEW ENGLAND MED CTR,SCH MED,GRASP,CTR DIGEST DIS,BOSTON,MA 02111.
   MED SCH HANNOVER,DEPT GEN PHARMACOL,W-3000 HANNOVER 61,GERMANY.
C3 Tufts Medical Center; Tufts University; Tufts University; Tufts Medical Center; Hannover Medical School
NR 15
TC 228
Z9 238
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 25
PY 1993
VL 362
IS 6418
BP 348
EP 350
DI 10.1038/362348a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KU176
UT WOS:A1993KU17600062
PM 8455720
DA 2026-03-10
ER

PT J
AU CERLING, TE
   WANG, Y
   QUADE, J
AF CERLING, TE
   WANG, Y
   QUADE, J
TI EXPANSION OF C4 ECOSYSTEMS AS AN INDICATOR OF GLOBAL ECOLOGICAL CHANGE IN THE LATE MIOCENE
SO NATURE
LA English
DT Article
ID carbon isotope; photosynthesis; paleosols; plants
AB THE most common and the most primitive pathway of the three different photosynthetic pathways used by plants is the C3 pathway, or Calvin cycle, which is characterized by an initial CO2 carboxylation to form phosphoglyceric acid, a 3-carbon acid. The carbon isotope composition (deletaC-13) of C3 plants varies from about -23 to -35 parts per thousand1-3 and averages about -26 parts per thousand. Virtually all trees, most shrubs, herbs and forbs, and cool-season grasses and sedges use the C3 pathway. In the C4 pathway (Hatch-Slack cycle), CO2 initially combines with phosphoenol pyruvate to form the 4-carbon acids malate or aspartic acid, which are translocated to bundle sheath cells where CO2 is released and used in Calvin cycle reactions1-4. The carbon isotope composition of C4 plants ranges from about -10 to -14 parts per thousand, averaging about -13 parts per thousand for modern plants1-3. Warm-season grasses and sedges are the most abundant C4 plants, although C4 photosynthesis is found in about twenty families5. The third photosynthetic pathway, CAM, combines features of both C3 and C4 pathways. CAM plants, which include many succulents, have intermediate carbon isotope compositions and are also adapted to conditions of water and CO2 stress. The modern global ecosystem has a significant component of C4 plants, primarily in tropical savannas, temperate grasslands and semi-desert scrublands. Studies of palaeovegetation from palaeosols and palaeodiet from fossil tooth enamel indicate a rapid expansion of C4 biomass in both the Old World and the New World starting 7 to 5 million years ago. We propose that the global expansion of C4 biomass may be related to lower atmospheric carbon dioxide levels because C4 photosynthesis is favoured over C3 photosynthesis when there are low concentrations of carbon dioxide in the atmosphere.
C1 UNIV ARIZONA,DEPT GEOSCI,TUCSON,AZ 85705.
C3 University of Arizona
RP CERLING, TE (corresponding author), UNIV UTAH,DEPT GEOL & GEOPHYS,SALT LAKE CITY,UT 84112, USA.
NR 32
TC 588
Z9 734
U1 1
U2 197
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 344
EP 345
DI 10.1038/361344a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000054
DA 2026-03-10
ER

PT J
AU ECKHARDT, CJ
   PEACHEY, NM
   SWANSON, DR
   TAKACS, JM
   KHAN, MA
   GONG, X
   KIM, JH
   WANG, J
   UPHAUS, RA
AF ECKHARDT, CJ
   PEACHEY, NM
   SWANSON, DR
   TAKACS, JM
   KHAN, MA
   GONG, X
   KIM, JH
   WANG, J
   UPHAUS, RA
TI SEPARATION OF CHIRAL PHASES IN MONOLAYER CRYSTALS OF RACEMIC AMPHIPHILES
SO NATURE
LA English
DT Article
ID langmuir-blodgett-films; resolution
AB OPTICAl activity manifested by chiral molecules and crystals is of long-standing interest in physics, chemistry, biology and geology1,2. The structure of chiral lattices in two and three dimensions may provide insights into chiral discrimination, and chiral phases play an important part in the physics and applications of liquid-crystal and amphiphilic films3-7. Here we report the observation of spontaneous separation of chiral phases in an oriented monolayer of rigid, chiral amphiphiles deposited on mica. Atomic force microscopy of the ordered films reveals domains of mirror-image structures. We propose that this may be the signature of separation into domains of pure enantiomers, although other possibilities exist. This separation of chiral phases in two dimensions may be considered analogous to the spontaneous resolution of enantiomers in three-dimensional crystallization, as exploited by Pasteur in 1848 to isolate enantiomers of sodium tartrate1.
C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011.
C3 Iowa State University; United States Department of Energy (DOE); Ames National Laboratory
RP ECKHARDT, CJ (corresponding author), UNIV NEBRASKA,DEPT CHEM,LINCOLN,NE 68588, USA.
NR 17
TC 145
Z9 147
U1 1
U2 41
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 614
EP 616
DI 10.1038/362614a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800040
DA 2026-03-10
ER

PT J
AU CHU, CW
   GAO, L
   CHEN, F
   HUANG, ZJ
   MENG, RL
   XUE, YY
AF CHU, CW
   GAO, L
   CHEN, F
   HUANG, ZJ
   MENG, RL
   XUE, YY
TI SUPERCONDUCTIVITY ABOVE 150-K IN HGBA2CA2CU3O8+DELTA AT HIGH-PRESSURES
SO NATURE
LA English
DT Article
AB RECENTLY, superconductivity at >130 K was reported1,2 in multi-phase samples of the compound system HgBa2Can-1CunO2n+2+delta (Hg-12(n-1)n) with n=1,2,3,.... Single-phase Hg-1223 was subsequently synthesized and found to be superconducting at a record temperature of 135 K (ref. 3). It remains to be seen if a much higher transition temperature (T(c)) than 135 K can be achieved in this compound system. The application of pressure generally increases the T(c) of underdoped layered cuprates, with a pressure derivative of T(c) that decreases with increasing doping4,5. Preliminary studies on Hg-1223(6) showed a pressure-induced increase in T(c) without any sign of saturation up to 17 kbar. Here we report the observation of superconductivity at up to 153 K in Hg-1223 at 150 kbar, with a main transition at 147 K. This observation provides an indication that superconductivity at >150 K may be possible in this system at ambient pressure, if suitable forms of chemical substitution can be found.
C1 UNIV HOUSTON,TEXAS CTR SUPERCONDUCT,HOUSTON,TX 77204.
C3 University of Houston System; University of Houston
RP CHU, CW (corresponding author), UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204, USA.
NR 11
TC 522
Z9 608
U1 3
U2 107
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 323
EP 325
DI 10.1038/365323a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600045
DA 2026-03-10
ER

PT J
AU YAMAZAKI, T
   WIDMANN, E
   HAYANO, RS
   IWASAKI, M
   NAKAMURA, SN
   SHIGAKI, K
   HARTMANN, FJ
   DANIEL, H
   VONEGIDY, T
   HOFMANN, P
   KIM, YS
   EADES, J
AF YAMAZAKI, T
   WIDMANN, E
   HAYANO, RS
   IWASAKI, M
   NAKAMURA, SN
   SHIGAKI, K
   HARTMANN, FJ
   DANIEL, H
   VONEGIDY, T
   HOFMANN, P
   KIM, YS
   EADES, J
TI FORMATION OF LONG-LIVED GAS-PHASE ANTIPROTONIC HELIUM-ATOMS AND QUENCHING BY H-2
SO NATURE
LA English
DT Article
ID metastable states; liquid-helium
AB IN 1964 Condo1 suggested that the decay characteristics of negative (pi- and K-) mesons in helium bubble chambers could be explained by the capture of these particles in large-angular-momentum metastable orbitals of exotic helium atoms. Russell2 predicted that similar 'atoms' might be formed by antiprotons in liquid helium. Nearly two decades later the postulated metastability of K- and pi- mesons in liquid helium was observed experimentally3-5. We recently observed6 that about 3% of the antiprotons stopped in liquid helium survive for several microseconds before annihilating in the helium nuclei. This is more than a million times longer than the typical (picosecond) lifetimes of antiprotons that come to rest in matter, and it represents the signature of the formation of metastable antiprotonic atoms. Here we show that the same phenomenon is observed in gas-phase helium, but that surprisingly the lifetime of the 'atoms' is the same as in the liquid phase, despite the reduction in collisional de-excitation. In addition. we show that the presence of trace amounts of hydrogen gas greatly reduces the lifetime, suggesting that a single collision with H-2 is sufficient to destroy the metastability.
C1 UNIV TOKYO,DEPT PHYS,BUNKYO KU,TOKYO 113,JAPAN.
   UNIV TOKYO,MESON SCI LAB,BUNKYO KU,TOKYO 113,JAPAN.
   TECH UNIV MUNICH,DEPT PHYS,W-8046 GARCHING,GERMANY.
   CERN,CH-1211 GENEVA 23,SWITZERLAND.
C3 University of Tokyo; University of Tokyo; Technical University of Munich; European Organization for Nuclear Research (CERN)
RP YAMAZAKI, T (corresponding author), UNIV TOKYO,INST NUCL STUDY,TANASHI,TOKYO 188,JAPAN.
NR 14
TC 177
Z9 178
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 21
PY 1993
VL 361
IS 6409
BP 238
EP 240
DI 10.1038/361238a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KH614
UT WOS:A1993KH61400051
DA 2026-03-10
ER

PT J
AU BUDD, G
AF BUDD, G
TI A CAMBRIAN GILLED LOBOPOD FROM GREENLAND
SO NATURE
LA English
DT Article
ID ribosomal-rna sequences; burgess shale; british-columbia; anomalocaris; affinity; arthropods; opabinia; origin; fauna
AB THE discovery of several 'Burgess Shale'-like faunas in the Cambrian has added significant new data to the debate about the nature of the 'Cambrian explosion'. Lobopod animals have emerged as a much more important component of the Cambrian fauna than of the Recent1,2. A new lobopod-like animal, Kerygmachela kierke-gaardi gen. et sp. nov., is now reported from the Lower Cambrian Sirius Passet fauna, north Greenland3. Although it shares features with other recently described lobopods, it differs in possessing lateral lobes along the body with dorsal gill-like structures attached to them, a feature that may indicate a relationship with the enigmatic Opabinia4. The presence of such a gilled lobopod suggests an evolutionary link between lobopods and the clade consisting of biramous-limbed arthropods5,6. The Cambrian lobopods thus represent a paraphyletic clade from which fully arthropodized taxa were derived. The data from Kerygmachela, when considered with recently published molecular data, may suggest a biphyletic origin for the arthropod grade of organization.
RP BUDD, G (corresponding author), UNIV CAMBRIDGE, DEPT EARTH SCI, DOWNING ST, CAMBRIDGE CB2 3EQ, ENGLAND.
NR 29
TC 116
Z9 127
U1 0
U2 12
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 709
EP 711
DI 10.1038/364709a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700054
DA 2026-03-10
ER

PT J
AU BISNOVATYLKOGAN, GS
   POSTNOV, KA
AF BISNOVATYLKOGAN, GS
   POSTNOV, KA
TI PULSAR MOTION EFFECT AND GEMINGAS HIGH BRAKING INDEX
SO NATURE
LA English
DT Article
ID field
AB THE pulsar braking index, n, is a dimensionless quantity describing the rate at which a magnetized neutron star loses rotational energy1. It can be determined from pulsar timing measurements, and for distant pulsars is found to lie close to n = 3 (ref. 2), as predicted by theoretical models of pulsar emission mechanisms3-5. In contrast, the timing parameters-in particular the second derivative of the pulsation frequency-of the nearby pulsar Geminga6-11 indicate an extremely large braking index of about 10-30. To understand this property of Geminga, we consider here the effect on the measured timing parameters of a pulsar's motion through space. We find that the Doppler effect alone can give a high apparent braking index, but only ff the pulsar is very close and has an abnormally high velocity (>1,000 km s-1). A more likely (but related) cause of the high braking index is the pulsar's proper motion: failure to correct for changes in the source coordinates with time can greatly influence the higher derivatives of the pulsar frequency, and lead to an erroneous value of n. A self-consistent analysis of the timing data, which account for both the proper motion and the Doppler effect, should permit a reliable estimate of the distance to Geminga.
C1 Moscow MV Lomonosov State Univ, Sternberg Astron Inst, MOSCOW 119992, RUSSIA.
C3 Lomonosov Moscow State University
RP BISNOVATYLKOGAN, GS (corresponding author), MOSCOW SPACE RES INST, PROFSOYUZNAYA ST 84-32, MOSCOW 117810, RUSSIA.
NR 20
TC 7
Z9 9
U1 0
U2 0
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 663
EP 665
DI 10.1038/366663a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500061
DA 2026-03-10
ER

PT J
AU HATA, Y
   SLAUGHTER, CA
   SUDHOF, TC
AF HATA, Y
   SLAUGHTER, CA
   SUDHOF, TC
TI SYNAPTIC VESICLE FUSION COMPLEX CONTAINS UNC-18 HOMOLOG BOUND TO SYNTAXIN
SO NATURE
LA English
DT Article
ID glutathione-s-transferase; caenorhabditis-elegans; escherichia-coli; purification; cleavage; proteins; cloning; family
AB THREE synaptic proteins, syntaxin, SNAP-25 and synaptobrevin, were recently identified as targets of clostridial neurotoxins that irreversibly inhibit synaptic vesicle fusion1-4. Experiments searching for membrane receptors for N-ethylmaleimide-sensitive fusion protein (NSF), which has an important role in membrane fusion, revealed an ATP-dependent interaction of the same three synaptic proteins with NSF and its soluble attachment proteins5. Thus, two independent approaches identify syntaxin, synaptobrevin and SNAP-25 as components of the synaptic vesicle fusion machinery, but their mode of action is unclear6. We have now discovered a brain protein of relative molecular mass 67,000 (67K) which binds stably to syntaxin. Amino-acid sequencing and complementary DNA cloning revealed that the 67K protein is encoded by the mammalian homologue of the Caenorhabditis elegans gene unc-18. In C. elegans, unc-18 belongs to a group of genes defined by mutations with a paralytic phenotype and accumulations of acetylcholine, suggesting a defect in neurotransmitter release7,8. The binding of the mammalian homologue of unc-18 (Munc-18) to syntaxin requires the N terminus of syntaxin whereas that of SNAP-25 involves a more C-terminal sequence. Our data suggest that Munc-18 is a previously unidentified essential component of the synaptic vesicle fusion protein complex.
C1 UNIV TEXAS,HLTH SCI CTR,SW MED SCH,HOWARD HUGHES MED INST,DALLAS,TX 75235.
   UNIV TEXAS,HLTH SCI CTR,SW MED SCH,DEPT MOLEC GENET,DALLAS,TX 75235.
C3 University of Texas System; University of Texas Dallas; University of Texas Southwestern Medical Center; Howard Hughes Medical Institute; University of Texas System; University of Texas Dallas; University of Texas Southwestern Medical Center
NR 30
TC 607
Z9 729
U1 1
U2 81
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 25
PY 1993
VL 366
IS 6453
BP 347
EP 351
DI 10.1038/366347a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MJ705
UT WOS:A1993MJ70500050
PM 8247129
DA 2026-03-10
ER

PT J
AU LINDSLEY, JE
   WANG, JC
AF LINDSLEY, JE
   WANG, JC
TI STUDY OF ALLOSTERIC COMMUNICATION BETWEEN PROTOMERS BY IMMUNOTAGGING
SO NATURE
LA English
DT Article
ID topoisomerase-ii; transition; dna
AB LIGAND-INDUCED allosteric changes in proteins are important in their cellular functions and regulation1,2, and both concerted and sequential examples are known3-5. The distinction has entailed elaborate analysis, however, and only a few systems have been unequivocally analysed. We have investigated the coupling between ATP usage and DNA transport by type II DNA topoisomerases6,7, and one key question concerning allostery in these dyadic enzymes is whether ATP binding to one protomer can induce a concerted conformational change in the entire enzyme. Here we use an enzyme with one immunotagged subunit defective in ATP binding and one wild-type subunit to show that it can. Our approach should be generally applicable in the study of allostery and communication between members of a macromolecular assembly.
RP LINDSLEY, JE (corresponding author), HARVARD UNIV,DEPT BIOCHEM & MOLEC BIOL,CAMBRIDGE,MA 02138, USA.
NR 9
TC 62
Z9 75
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 25
PY 1993
VL 361
IS 6414
BP 749
EP 750
DI 10.1038/361749a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KN789
UT WOS:A1993KN78900064
PM 7680110
DA 2026-03-10
ER

PT J
AU THERIAULT, Y
   LOGAN, TM
   MEADOWS, R
   YU, LP
   OLEJNICZAK, ET
   HOLZMAN, TF
   SIMMER, RL
   FESIK, SW
AF THERIAULT, Y
   LOGAN, TM
   MEADOWS, R
   YU, LP
   OLEJNICZAK, ET
   HOLZMAN, TF
   SIMMER, RL
   FESIK, SW
TI SOLUTION STRUCTURE OF THE CYCLOSPORINE-A CYCLOPHILIN COMPLEX BY NMR
SO NATURE
LA English
DT Article
ID cis-trans isomerase; binding-protein; conformation
AB CYCLOSPORIN A, a cyclic undecapeptide, is a potent immunosuppressant that binds to a peptidyl-prolyl cis-trans isomerase1,2 of 165 amino acids, cyclophilin3. The cyclosporin A/cyclophilin complex inhibits the calcium- and calmodulin-dependent phosphatase, calcineurin4, resulting in a failure to activate genes encoding interleukin-2 and other lymphokines5,6. The three-dimensional structures of uncomplexed cyclophilin7, a tetrapeptide/cyclophilin complex8,9, and cyclosporin A when bound to cyclophilin10,11 have been reported. However, the structure of the cyclosporin A/cyclophilin complex has not been determined. Here we present the solution structure of the cyclosporin A/cyclophilin complex obtained by heteronuclear three-dimensional NMR spectroscopy. The structure, one of the largest determined by NMR, differs from proposed models of the complex12-14 and is analysed in terms of the binding interactions and structure/activity relationships for CsA analogues15,16.
C1 ABBOTT LABS,DIV PHARMACEUT DISCOVERY,ABBOTT PK,IL 60064.
C3 Abbott Laboratories
NR 31
TC 179
Z9 190
U1 0
U2 21
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 7
PY 1993
VL 361
IS 6407
BP 88
EP 91
DI 10.1038/361088a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KF718
UT WOS:A1993KF71800056
PM 8421500
DA 2026-03-10
ER

PT J
AU SPIVACK, AJ
   YOU, CF
   SMITH, HJ
AF SPIVACK, AJ
   YOU, CF
   SMITH, HJ
TI FORAMINIFERAL BORON ISOTOPE RATIOS AS A PROXY FOR SURFACE OCEAN PH OVER THE PAST 21-MYR
SO NATURE
LA English
DT Article
ID dsdp interstitial waters; carbon-dioxide; exchange; cycle; crust; sea
AB THE pH of the surface ocean is a sensitive function of its alkalinity and total inorganic carbon concentration, properties which also control the partial pressure of atmospheric carbon dioxide17. Thus, an accurate proxy for past ocean pH could yield information about variations in atmospheric CO2. Recently, it has been suggested that the boron isotopic composition of foraminiferal tests depends on the pH of sea water as well as its isotopic composition1,2. Here we present boron isotope and elemental data for sedimentary pore fluids and isotope data for bulk foraminiferal samples from a deep-sea sediment core. The composition of the pore waters implies that sea water boron concentrations and isotopic composition have been constant during the past 21 Myr, allowing us to reconstruct past ocean pH directly from the foraminiferal isotope data. We find that 21 Myr ago, surface ocean pH was only 7.4 +/- 0.2, but it then increased to 8.2 +/- 0.2 (roughly the present value) about 7.5 Myr ago. This is consistent with suggestions3-5 that atmospheric CO2 concentrations may have been much higher 21 Myr ago than today.
RP SPIVACK, AJ (corresponding author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,9500 GILMAN DR,LA JOLLA,CA 92093, USA.
NR 23
TC 189
Z9 238
U1 2
U2 63
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 149
EP 151
DI 10.1038/363149a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100043
DA 2026-03-10
ER

PT J
AU GAUCHAT, JF
   HENCHOZ, S
   MAZZEI, G
   AUBRY, JP
   BRUNNER, T
   BLASEY, H
   LIFE, P
   TALABOT, D
   FLORESROMO, L
   THOMPSON, J
   KISHI, K
   BUTTERFIELD, J
   DAHINDEN, C
   BONNEFOY, JY
AF GAUCHAT, JF
   HENCHOZ, S
   MAZZEI, G
   AUBRY, JP
   BRUNNER, T
   BLASEY, H
   LIFE, P
   TALABOT, D
   FLORESROMO, L
   THOMPSON, J
   KISHI, K
   BUTTERFIELD, J
   DAHINDEN, C
   BONNEFOY, JY
TI INDUCTION OF HUMAN IGE SYNTHESIS IN B-CELLS BY MAST-CELLS AND BASOPHILS
SO NATURE
LA English
DT Article
ID messenger-rna; interleukin-4; ligand; cd40; identification; cyclosporine; leukemia; line
AB IMMUNOGLOBULIN E (IgE) is central to the induction of allergic diseases through its binding to the high-affinity receptor (FcepsilonR1) on mast cells and basophils. Crosslinking by allergens of the bound IgE leads to the release of various inflammatory mediators. IgE production by B cells requires a physical interaction with T cells1, involving a number of surface adhesion molecules1,2, as well as the soluble factors interleukin-4 (IL-4)3,4 and IL-13 (ref. 5) produced by T cells6,7, basophils8 and mast cells9. Here we report that, in the presence of IL-4, mast and basophilic cell lines can provide the cell contact signals that are required for IgE synthesis. The human cell lines HMC-1 (mast) and KU812 (basophilic) both express the ligand for CD40 (CD40L) which is shown to be responsible for the IgE production. Moreover, freshly isolated purified human lung mast cells and blood basophils are also shown to express CD40L and to induce IgE production. This evidence suggests that mast cells and basophils may therefore play a key role in allergy not only by producing inflammatory mediators, but also by directly regulating IgE production independently of T cells.
C1 GLAXO INST MOLEC BIOL,14 CHEMIN AULX,CH-1228 PLAN LES OUATES,SWITZERLAND.
   INSELSPITAL BERN,CH-3010 BERN,SWITZERLAND.
   GLAXO GRP RES LTD,GREENFORD UB6 0HE,MIDDX,ENGLAND.
   NIIGATA UNIV,NIIGATA 951,JAPAN.
   MAYO CLIN & MAYO FDN,ROCHESTER,MN 55905.
C3 GlaxoSmithKline; GlaxoSmithKline Switzerland; GlaxoSmithKline; Glaxosmithkline United Kingdom; Niigata University; Mayo Clinic
NR 29
TC 578
Z9 632
U1 1
U2 19
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 340
EP 343
DI 10.1038/365340a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600052
PM 7690905
DA 2026-03-10
ER

PT J
AU FORLONI, G
   ANGERETTI, N
   CHIESA, R
   MONZANI, E
   SALMONA, M
   BUGIANI, O
   TAGLIAVINI, F
AF FORLONI, G
   ANGERETTI, N
   CHIESA, R
   MONZANI, E
   SALMONA, M
   BUGIANI, O
   TAGLIAVINI, F
TI NEUROTOXICITY OF A PRION PROTEIN-FRAGMENT
SO NATURE
LA English
DT Article
ID rat ventral prostate; scrapie prion; amyloid protein; messenger-rna; cell-death; identification; brain; apoptosis; purification; disease
AB THE cellular prion protein (PrP(C)) is a sialoglycoprotein of M(r) 33-35K that is expressed predominantly in neurons1-3. In transmissible and genetic neurodegenerative disorders such as scrapie of sheep, spongiform encephalopathy of cattle and Creutzfeldt-Jakob or Gerstmann-Straussler-Scheinker diseases of humans4,5, PrP(C) is converted into an altered form (termed PrP(Sc)) which is distinguishable from its normal homologue by its relative resistance to protease digestion6-8. PrP(Sc) accumulates in the central nervous system of affected individuals8,9 and its protease-resistant core aggregates extracellularly into amyloid fibrils10-12.  The process is accompanied by nerve cell loss, whose pathogenesis and molecular basis are not understood. We report here that neuronal death results from chronic exposure of primary rat hippocampal cultures to micromolar concentrations of a peptide corresponding to residues 106-126 of the amino-acid sequence deduced from human PrP complementary DNA. DNA fragmentation of degenerating neurons indicates that cell death occurred by apoptosis. The PrP peptide 106-126 has a high intrinsic ability to polymerize into amyloid-like fibrils in vitro. These findings indicate that cerebral accumulation of PrP(Sc) and its degradation products may play a role in the nerve cell degeneration that occurs in prion-related encephalopathies.
C1 IST NAZL NEUROL CARLO BESTA,I-20133 MILAN,ITALY.
C3 Fondazione IRCCS Istituto Neurologico Carlo Besta
RP FORLONI, G (corresponding author), MARIO NEGRI INST PHARMACOL RES,VIA ERITREA 62,I-20157 MILAN,ITALY.
NR 35
TC 901
Z9 973
U1 0
U2 46
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 8
PY 1993
VL 362
IS 6420
BP 543
EP 546
DI 10.1038/362543a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KW453
UT WOS:A1993KW45300055
PM 8464494
DA 2026-03-10
ER

PT J
AU LAIDLAW, WM
   DENNING, RG
   VERBIEST, T
   CHAUCHARD, E
   PERSOONS, A
AF LAIDLAW, WM
   DENNING, RG
   VERBIEST, T
   CHAUCHARD, E
   PERSOONS, A
TI LARGE 2ND-ORDER OPTICAL POLARIZABILITIES IN MIXED-VALENCY METAL-COMPLEXES
SO NATURE
LA English
DT Article
ID nonlinearity; hyperpolarizability; molecules
AB THE potential development of optoelectronic devices based on the nonlinear polarization of molecular materials has aroused much recent interest1,2. The search for large second-order electric susceptibilities (that is, proportional to the square of an applied electric field) has concentrated on acentric organic or organometallic chromophores with an organic pi-electron system coupling electron donor and acceptor groups3-6. It is conceivable that mixed-valence compounds characterized by an intervalence charge-transfer (IVCT) transition7, in which the donor and acceptor centres are both metal atoms, might also have the potential to provide a large second-order response8, but this possibility has not been widely explored. Here we report the first hyperpolarizability, beta, of a bimetallic complex ion, [(CN)5Ru-mu-CN-Ru(NH3)5]- (I in Fig. 1), and a novel organometallic analogue, [(eta5-C5H5)Ru(PPh3)2-mu-CN-Ru(NH3)5]3+ (II). Measurements of beta (which is related to the bulk second-order response) in solution at a wavelength of 1,064 nm using the newly developed hyper-Rayleigh scattering technique9,10 give values greater than 10(-27) e.s.u., which are among the largest reported for solution species. The ease with which the energy of the IVCT transition can be modified suggests that there may be considerable potential for this class of chromophore in nonlinear optical devices.
C1 UNIV OXFORD,INORGAN CHEM LAB,S PARKS RD,OXFORD OX1 3QR,ENGLAND.
   UNIV LEUVEN,CHEM & BIOL DYNAM LAB,B-3001 LOUVAIN,BELGIUM.
C3 University of Oxford; KU Leuven
NR 28
TC 188
Z9 193
U1 0
U2 27
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 58
EP 60
DI 10.1038/363058a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200055
DA 2026-03-10
ER

PT J
AU LIN, SC
   LIN, CJR
   GUKOVSKY, I
   LUSIS, AJ
   SAWCHENKO, PE
   ROSENFELD, MG
AF LIN, SC
   LIN, CJR
   GUKOVSKY, I
   LUSIS, AJ
   SAWCHENKO, PE
   ROSENFELD, MG
TI MOLECULAR-BASIS OF THE LITTLE MOUSE PHENOTYPE AND IMPLICATIONS FOR CELL-TYPE-SPECIFIC GROWTH
SO NATURE
LA English
DT Article
ID hormone-releasing-factor; anterior-pituitary cells; pancreatic-islet tumor; transgenic mice; messenger-rna; dwarf mice; thyroid-cells; cyclic-amp; protein; gene
AB The molecular basis for the little (lit) mouse phenotype, characterized by a hypoplastic anterior pituitary gland, is the mutation of a single nucleotide that alters Asp 60 to Gly in the growth hormone releasing factor receptor. Detailed analysis of the lit mouse anterior pituitary reveals spatially distinct proliferative zones of growth hormone-producing stem cells and mature somatotrophs, each regulated by a different trophic factor. This sequential growth factor requirement for a specific cell type may exemplify a common strategy for regulating cellular proliferation in other mammalian organs.
C1 UNIV CALIF SAN DIEGO, DEPT MED, LA JOLLA, CA 92093 USA.
   UNIV CALIF LOS ANGELES, DEPT MICROBIOL & MOLEC GENET, LOS ANGELES, CA 90024 USA.
   UNIV CALIF LOS ANGELES, DEPT MED, LOS ANGELES, CA 90024 USA.
   UNIV CALIF LOS ANGELES, INST MOLEC BIOL, LOS ANGELES, CA 90024 USA.
   SALK INST BIOL STUDIES, NEURONAL STRUCT & FUNCT LAB, LA JOLLA, CA 92037 USA.
C3 University of California System; University of California San Diego; University of California System; University of California Los Angeles; University of California System; University of California Los Angeles; University of California System; University of California Los Angeles; Salk Institute
RP LIN, SC (corresponding author), UNIV CALIF SAN DIEGO, SCH MED, HOWARD HUGHES MED INST, EUKARYOT REGULATORY BIOL PROGRAM, LA JOLLA, CA 92093 USA.
NR 54
TC 429
Z9 444
U1 0
U2 13
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 208
EP 213
DI 10.1038/364208a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300047
PM 8391647
DA 2026-03-10
ER

PT J
AU PHIPPS, BM
   TYPKE, D
   HEGERL, R
   VOLKER, S
   HOFFMANN, A
   STETTER, KO
   BAUMEISTER, W
AF PHIPPS, BM
   TYPKE, D
   HEGERL, R
   VOLKER, S
   HOFFMANN, A
   STETTER, KO
   BAUMEISTER, W
TI STRUCTURE OF A MOLECULAR CHAPERONE FROM A THERMOPHILIC ARCHAEBACTERIUM
SO NATURE
LA English
DT Article
ID heat-shock; 3-dimensional reconstruction; protein; binding; carboxylase; plant; groel; atp
AB WE recently reported that a wide range of thermophilic archaebacteria have a novel ATPase complex which accumulates to high levels upon heat shock and may be a new type of molecular chaperone related to the chaperonins1. Striking similarities between the complex, referred to here as the 'thermosome', and the subsequently characterized chaperones TF55 of the thermophilic archaebacterium Sulfolobus shibatae2 and TCP-1 from eukaryotic cytosol2-5 suggest that these proteins belong to a single family. Here we determine the three-dimensional structure of the thermosome from Pyrodictium occultum by random conical tilt reconstruction from electron micrographs. The reconstruction reveals a complex consisting of two rings of eight subunits each, stacked face-to-face. The subunits are kidney-shaped and composed of at least two domains. In the centre of the thermosome is a large cavity of about 6.7 nm diameter; the opening of this cavity on each face of the complex is partially blocked by a mass which appears to be weakly connected to the eight-membered ring.
C1 MAX PLANCK INST BIOCHEM,W-8033 MARTINSRIED,GERMANY.
   UNIV REGENSBURG,DEPT MICROBIOL,W-8400 REGENSBURG,GERMANY.
C3 Max Planck Society; University of Regensburg
NR 29
TC 127
Z9 130
U1 1
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 4
PY 1993
VL 361
IS 6411
BP 475
EP 477
DI 10.1038/361475a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KK713
UT WOS:A1993KK71300069
DA 2026-03-10
ER

PT J
AU FRANCIS, CL
   RYAN, TA
   JONES, BD
   SMITH, SJ
   FALKOW, S
AF FRANCIS, CL
   RYAN, TA
   JONES, BD
   SMITH, SJ
   FALKOW, S
TI RUFFLES INDUCED BY SALMONELLA AND OTHER STIMULI DIRECT MACROPINOCYTOSIS OF BACTERIA
SO NATURE
LA English
DT Article
ID epidermal growth-factor; carcinoma-cells a-431; cultured-mammalian-cells; factor receptor; cytoskeletal changes; epithelial-cells; tyrosine kinase; kb-cells; membrane; typhimurium
AB RUFFLES are specialized plasma membrane ultrastructures of mammalian cells thought to be integral to growth, development and locomotion1-4. Induced by growth factors5-8, mitogens9 or oncogene expression10,11, ruffles are sites of filamentous actin rearrangement7,8 and are temporally associated with enhanced pinocytosis10,12. But the function of ruffles, their mechanism of induction and their role in pinocytosis are not understood. We have observed formation of structures resembling ruffles associated with the site of entry of invasive Salmonella typhimurium13. Here we report that ruffles elicited by invasive Salmonella directly mediate internalization of non-invasive bacteria in a macropinocytotic fashion, a phenomenon we term 'passive entry'. Furthermore, ruffles induced in the absence of Salmonella also facilitate passive entry. We present evidence that ruffles, common to many signalling events, comprise the macropinocytotic machinery mediating pinocytosis and are subverted by Salmonella so as to enter mammalian cells.
C1 STANFORD UNIV,DEPT MOLEC & CELLULAR PHYSIOL,STANFORD,CA 94305.
   NIH,ROCKY MT LAB,HAMILTON,MT 59840.
C3 Stanford University; National Institutes of Health (NIH) - USA; NIH National Institute of Allergy & Infectious Diseases (NIAID)
RP FRANCIS, CL (corresponding author), STANFORD UNIV,DEPT MICROBIOL & IMMUNOL,STANFORD,CA 94305, USA.
NR 30
TC 375
Z9 431
U1 0
U2 19
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 639
EP 642
DI 10.1038/364639a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100056
PM 8350922
DA 2026-03-10
ER

PT J
AU PIMPLIKAR, SW
   SIMONS, K
AF PIMPLIKAR, SW
   SIMONS, K
TI REGULATION OF APICAL TRANSPORT IN EPITHELIAL-CELLS BY A G(S) CLASS OF HETEROTRIMERIC G-PROTEIN
SO NATURE
LA English
DT Article
ID gtp-binding proteins; mdck cells; surface; mastoparan; membranes; domains
AB THE role of heterotrimeric GTP-binding proteins in signal transduction is well established1. They might also be involved in vesicular transport2-6. Here we show that in the epithelial cell line Madin-Darby Canine Kidney, transport of influenza haemagglutinin protein to the apical surface is stimulated and that of vesicular stomatitis virus glycoprotein to the basolateral surface is retarded by AlF(3-5) treatment. Treatment of cells with the reagents known to influence the G(i) class of G proteins affected only the basolateral pathway whereas reagents acting on the G(s) class of G proteins specifically affected the apical pathway. In permeabilized cells, antibodies raised against the N-terminal domain of the alpha-subunit of G(s) inhibited the transport of haemagglutinin from the trans-Golgi network to apical surface but not between the endoplasmic reticulum and Golgi complex. These observations demonstrate involvement of a G(s) class of heterotrimeric G proteins, besides that of the G(i), in vesicular transport2. Moreover, the apical and the basolateral pathways in epithelial cells seem to be regulated by G(s) and G(i) proteins, respectively, in the trans-Golgi network.
C1 EUROPEAN MOLEC BIOL LAB,CELL BIOL PROGRAMME,POSTFACH 102209,W-6900 HEIDELBERG,GERMANY.
C3 European Molecular Biology Laboratory (EMBL)
NR 23
TC 187
Z9 192
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 1
PY 1993
VL 362
IS 6419
BP 456
EP 458
DI 10.1038/362456a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KV424
UT WOS:A1993KV42400086
PM 8385268
DA 2026-03-10
ER

PT J
AU HAMMOND, SA
   BOLLINGER, RC
   TOBERY, TW
   SILICIANO, RF
AF HAMMOND, SA
   BOLLINGER, RC
   TOBERY, TW
   SILICIANO, RF
TI TRANSPORTER-INDEPENDENT PROCESSING OF HIV-1 ENVELOPE PROTEIN FOR RECOGNITION BY CD8+ T-CELLS
SO NATURE
LA English
DT Article
ID toxic lymphocytes-t; major histocompatibility complex; class-ii region; endoplasmic-reticulum; antigen presentation; signal sequence; virus; mhc; expression; gene
AB CD8+ cytolytic T lymphocytes (CTL) identify virally infected cells by recognizing processed viral antigen in association with class I major histocompatibility complex (MHC) molecules on infected cells1-4. Processing begins in the cytosol5-7 with the generation of peptides, possibly by a protease complex with MHC-encoded subunits, known as the proteasome8-11. Transport of the resulting cytosolic peptides into the endoplasmic reticulum for association with class I molecules is essential and probably involves a heterodimer of the MHC-encoded proteins, Tap-1 and Tap-2(12-17). The site of processing of viral envelope proteins is uncertain. These proteins are not present in the cytosol because of cotranslational translocation into the endoplasmic reticulum. We show here that the HIV-1 envelope (env) protein is processed in infected cells by a novel Tap-1/Tap-2-independent pathway that seems to be localized to the endoplasmic reticulum.
RP HAMMOND, SA (corresponding author), JOHNS HOPKINS UNIV,SCH MED,DEPT MED,BALTIMORE,MD 21205, USA.
NR 50
TC 97
Z9 98
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 158
EP 161
DI 10.1038/364158a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700053
PM 8321286
DA 2026-03-10
ER

PT J
AU YANG, J
   ELLINOR, PT
   SATHER, WA
   ZHANG, JF
   TSIEN, RW
AF YANG, J
   ELLINOR, PT
   SATHER, WA
   ZHANG, JF
   TSIEN, RW
TI MOLECULAR DETERMINANTS OF CA2+ SELECTIVITY AND ION PERMEATION IN L-TYPE CA2+ CHANNELS
SO NATURE
LA English
DT Article
ID sensitive calcium-channel; mono-valent cations; concentration-dependence; functional expression; k+ channel; pore; mutations; binding; blockade; voltage
AB VOLTAGE-GATED Ca2+ channels link changes in membrane potential to the delivery of Ca2+, a key second messenger for many cellular responses1. Ca2+ channels show selectivity for Ca2+ over more plentiful ions such as Na+ or K+ by virtue of their high-affinity binding of Ca2+ within the pore2-6. It has been suggested that this binding involves four conserved glutamate residues7-10 in equivalent positions in the putative pore-lining regions of repeats I-IV in the Ca2+ channel alpha1 subunit. We have carried out a systematic series of single amino-acid substitutions in each of these positions and find that all four glutamates participate in high-affinity binding of Ca2+ or Cd2+. Each glutamate carboxylate makes a distinct contribution to ion binding, with the carboxylate in repeat III having the strongest effect. Some single glutamate-to-lysine mutations completely abolish micromolar Ca2+ block, indicating that the pore does not possess any high-affinity binding site that acts independently of the four glutamate residues. The prevailing model of Ca2+ permeation2,3 must thus be modified to allow binding of two Ca2+ ions in close proximity11,12, within the sphere of influence of the four glutamates. The functional inequality of the glutamates may be advantageous in allowing simultaneous interactions with multiple Ca2+ ions moving single-file within the pore. Competition among Ca2+ ions for individual glutamates11,12, together With repulsive ion-ion electrostatic interaction2,3, may help achieve rapid flux rates through the channel2-5.
C1 STANFORD UNIV, MED CTR, BECKMAN CTR, DEPT MOLEC & CELLULAR PHYSIOL, STANFORD, CA 94305 USA.
C3 Stanford University
NR 30
TC 529
Z9 606
U1 3
U2 26
PU NATURE RESEARCH
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD NOV 11
PY 1993
VL 366
IS 6451
BP 158
EP 161
DI 10.1038/366158a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MG216
UT WOS:A1993MG21600058
PM 8232554
DA 2026-03-10
ER

PT J
AU FLEGAL, AR
   MARING, H
   NIEMEYER, S
AF FLEGAL, AR
   MARING, H
   NIEMEYER, S
TI ANTHROPOGENIC LEAD IN ANTARCTIC SEA-WATER
SO NATURE
LA English
DT Article
ID weddell sea; contamination; pollution; cadmium; copper; column; fluxes; metals; soils; snow
AB ANTARCTICA is believed to be a relatively pristine continent, mainly because of its remote location and the atmospheric circulation patterns that limit the transport of industrial aerosols into the Antarctic polar cell1-4. This perception is apparently supported by the extremely low concentrations of lead in Antarctic surface waters-an observation that has been interpreted as showing insignificant contamination by anthropogenic lead5. The isotopic composition of lead in other natural waters has been used as a tracer of the sources of lead, and in particular to identify anthropogenic inputs6,7. Here we apply this approach to Antarctic surface waters, and show that despite the low concentrations of lead in these waters (which are confirmed by our measurements), their isotopic composition reveals a significant contribution of lead from industrial sources. The extremely low concentrations of lead in these waters appear to be due to biological scavenging of the lead during periods of intense primary production.
C1 UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,DIV MARINE & ATMOSPHER CHEM,MIAMI,FL 33149.
   LAWRENCE LIVERMORE NATL LAB,DIV NUCL CHEM,LIVERMORE,CA 94550.
C3 University of Miami; United States Department of Energy (DOE); Lawrence Livermore National Laboratory
RP FLEGAL, AR (corresponding author), UNIV CALIF SANTA CRUZ,EARTH SCI BOARD,SANTA CRUZ,CA 95064, USA.
NR 26
TC 73
Z9 80
U1 1
U2 23
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 16
PY 1993
VL 365
IS 6443
BP 242
EP 244
DI 10.1038/365242a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LX471
UT WOS:A1993LX47100050
DA 2026-03-10
ER

PT J
AU WALWORTH, N
   DAVEY, S
   BEACH, D
AF WALWORTH, N
   DAVEY, S
   BEACH, D
TI FISSION YEAST CHK1-PROTEIN KINASE LINKS THE RAD CHECKPOINT PATHWAY TO CDC2
SO NATURE
LA English
DT Article
ID tyrosine phosphatase; gene
AB THE dependence of cell-cycle progression on the integrity of the genome has been described as checkpoint control1,2. A number of mutants of the fission yeast Schizosaccharomyces pombe, selected for their sensitivity to DNA damage caused by radiation (rad mutants) or to the DNA synthesis inhibitor hydroxyurea (hus mutants) have been classified as checkpoint mutants because they fail to arrest the cell cycle in response to DNA damage or incompletely replicated DNA3-6. Coupling of the checkpoint pathways that monitor DNA repair and replication to control of the cell cycle is essential. In a search for components that interact with the cell-cycle regulatory kinase p34cdc2, we have identified a novel fission yeast protein kinase homologue which is involved in cell-cycle arrest when DNA damage has occurred or when unligated DNA is present. We have called the gene encoding this protein chk1 for checkpoint kinase. Multiple copies of chk1 partially rescue the ultraviolet sensitivity of rad1-1, a mutant deficient in checkpoint control3-5. Identification of a gene involved in checkpoint control as a rescue of a cdc2 mutant links the rad1-dependent DNA-damage-sensing pathway and p34cdc2 activity.
C1 COLD SPRING HARBOR LAB, HOWARD HUGHES MED INST, COLD SPRING HARBOR, NY 11724 USA.
C3 Cold Spring Harbor Laboratory; Howard Hughes Medical Institute
NR 19
TC 419
Z9 475
U1 0
U2 7
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 27
PY 1993
VL 363
IS 6427
BP 368
EP 371
DI 10.1038/363368a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LD917
UT WOS:A1993LD91700059
PM 8497322
DA 2026-03-10
ER

PT J
AU HO, K
   NICHOLS, CG
   LEDERER, WJ
   LYTTON, J
   VASSILEV, PM
   KANAZIRSKA, MV
   HEBERT, SC
AF HO, K
   NICHOLS, CG
   LEDERER, WJ
   LYTTON, J
   VASSILEV, PM
   KANAZIRSKA, MV
   HEBERT, SC
TI CLONING AND EXPRESSION OF AN INWARDLY RECTIFYING ATP-REGULATED POTASSIUM CHANNEL
SO NATURE
LA English
DT Article
ID cftr chloride channel; cystic-fibrosis gene; squid giant-axon; k+ channels; sodium-channel; rat-brain; functional expression; complementary-dna; membrane-protein; shaker locus
AB A complementary DNA encoding an ATP-regulated potassium channel has been isolated by expression cloning from rat kidney. The predicted 45K protein, which features two potential membrane-spanning helices and a proposed ATP-binding domain, represents a major departure from the basic structural design characteristic of voltage-gated and second messenger-gated ion channels. But the presence of an HS region, which is likely to form the ion conduction pathway, indicates that the protein may share a common origin with voltage-gated potassium channel proteins.
C1 HARVARD UNIV, SCH MED, HARVARD CTR STUDY KIDNEY DIS, 75 FRANCIS ST, BOSTON, MA 02115 USA.
   BRIGHAM & WOMENS HOSP, DEPT MED, DIV RENAL, MOLEC PHYSIOL & BIOPHYS LAB, BOSTON, MA 02115 USA.
   WASHINGTON UNIV, MED CTR, SCH MED, DEPT CELL BIOL & PHYSIOL, ST LOUIS, MO 63110 USA.
   UNIV MARYLAND, DEPT PHYSIOL, BALTIMORE, MD 21201 USA.
   BRIGHAM & WOMENS HOSP, DEPT MED, DIV ENDOCRINE & HYPERTENS, BOSTON, MA 02115 USA.
C3 Harvard University; Harvard Medical School; Harvard University; Harvard University Medical Affiliates; Brigham & Women's Hospital; Washington University (WUSTL); University System of Maryland; University of Maryland Baltimore; Harvard University; Harvard University Medical Affiliates; Brigham & Women's Hospital
NR 102
TC 887
Z9 987
U1 0
U2 27
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 31
EP 38
DI 10.1038/362031a0
PG 8
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600050
PM 7680431
DA 2026-03-10
ER

PT J
AU DYNLACHT, BD
   WEINZIERL, ROJ
   ADMON, A
   TJIAN, R
AF DYNLACHT, BD
   WEINZIERL, ROJ
   ADMON, A
   TJIAN, R
TI THE DTAF(II)80 SUBUNIT OF DROSOPHILA TFIID CONTAINS BETA-TRANSDUCIN REPEATS
SO NATURE
LA English
DT Article
ID saccharomyces-cerevisiae; glucose repression; protein; gene; cdc4; coactivators; expression; homology; sequence; complex
AB A KEY component of the RNA polymerase II transcriptional apparatus, TFIID, is a multi-protein complex containing the TATA box-binding protein (TBP) and at least seven tightly associated factors (TAFs)1,2. Although the functions of most TFIID subunits are unknown, it is clear that TAFs are not necessary for basal activity but that one or more are required for regulated transcription, and so behave as coactivators1-4. The presence of multiple subunits indicates that there is an intricate assembly process and that TAFs may be responsible for other activities. We have described the properties of the subunit dTAF(II)110, which can interact directly with the transcriptional activator Sp1 (ref. 5). In addition, the largest subunit, dTAF(II)250, binds directly to TBP and links other TAFs to the complex6. Here we describe the cloning, expression and partial characterization of the Drosophila TAF of M(r) 80,000, dTAF(II)80. Sequence analysis reveals that dTAF(II)80 contains several copies of the WD40 (beta-transducin) repeat7. Moreover, dTAF(II)80 shares extended sequence similarity with an Arabidopsis gene, COP1, which encodes a putative transcription factor that is thought to regulate development8. We have expressed recombinant dTAF(II)80 and begun to characterize its interaction with other members of the TFIID complex. Purified recombinant dTAF(II)80 is unable to bind TBP directly or to interact strongly with the C-terminal domain of dTAF(II)250 (DELTAN250). Instead, dTAF(II)80 is only able to recognize and interact with a higher-order complex containing TBP, DELTAN250, 110 and 60. These findings suggest the formation of TFIID may require an ordered assembly of the TAFs, some of which bind directly to TBP and others that are tethered to the complex as a result of specific TAF/TAF interactions.
C1 UNIV CALIF BERKELEY,DEPT MOLEC & CELL BIOL,HOWARD HUGHES MED INST,BERKELEY,CA 94720.
C3 Howard Hughes Medical Institute; University of California System; University of California Berkeley
NR 22
TC 118
Z9 124
U1 0
U2 4
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 176
EP 179
DI 10.1038/363176a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100052
PM 8483503
DA 2026-03-10
ER

PT J
AU LANE, HA
   FERNANDEZ, A
   LAMB, NJC
   THOMAS, G
AF LANE, HA
   FERNANDEZ, A
   LAMB, NJC
   THOMAS, G
TI P70(S6K) FUNCTION IS ESSENTIAL FOR G1-PROGRESSION
SO NATURE
LA English
DT Article
ID protein-kinase; ribosomal protein-s6; dependent protein; dna-synthesis; map2 kinase; s6 kinase; rat-liver; phosphorylation; fibroblasts; serum
AB AN essential step in the pathway by which growth factors trigger cellular proliferation is the induction of high levels of protein synthesis1-3. This appears in part to be controlled by multiple phosphorylation of the ribosomal protein S6 (refs 4, 5). The main kinase responsible, p70s6k (refs 6-8), is activated through the phosphorylation of four sites clustered in a putative autoinhibitory domain9, which is mediated by a signalling pathway distinct from those used by other well characterized mitogen-activated serine/threonine kinases (such as p42/p44mapk or p90rsk; refs 10, 11). Here we investigate the role of p70s6k in the mitogenic response. Microinjection of quiescent rat embryo fibroblasts with any of three distinct polyclonal antibodies to p70s6k abolishes serum-induced entry into S phase of the cell cycle. This effect is preceded by almost complete abrogation of the activation of protein synthesis and the expression of an essential immediate early gene product, c-fos. The inhibitory effect on DNA synthesis is also elicited by microinjection of the antibodies late in G1 phase, consistent with the finding that p70s6k activity remains high throughout G1.
C1 FRIEDRICH MIESCHER INST, POB 2543, CH-4002 BASEL, SWITZERLAND.
   CNRS, INSERM, F-34033 MONTPELLIER, FRANCE.
C3 Friedrich Miescher Institute for Biomedical Research; Institut National de la Sante et de la Recherche Medicale (Inserm); Centre National de la Recherche Scientifique (CNRS); Universite de Montpellier
NR 29
TC 351
Z9 367
U1 0
U2 3
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 170
EP 172
DI 10.1038/363170a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100050
PM 8483501
DA 2026-03-10
ER

PT J
AU KENYON, C
   CHANG, J
   GENSCH, E
   RUDNER, A
   TABTIANG, R
AF KENYON, C
   CHANG, J
   GENSCH, E
   RUDNER, A
   TABTIANG, R
TI A C-ELEGANS MUTANT THAT LIVES TWICE AS LONG AS WILD-TYPE
SO NATURE
LA English
DT Article
ID nematode caenorhabditis-elegans; life-span; genetic-analysis; dauer larva; senescence
AB WE have found that mutations in the gene daf-2 can cause fertile, active, adult Caenorhabditis elegans hermaphrodites to live more than twice as long as wild type. This lifespan extension, the largest yet reported in any organism1, requires the activity of a second gene, daf-16. Both genes also regulate formation of the dauer larva, a developmentally arrested larval form that is induced by crowding and starvation and is very long-lived2-4. Our findings raise the possibility that the longevity of the dauer is not simply a consequence of its arrested growth, but instead results from a regulated lifespan extension mechanism that can be uncoupled from other aspects of dauer formation. daf-2 and daf-16 provide entry points into understanding how lifespan can be extended.
RP KENYON, C (corresponding author), UNIV CALIF SAN FRANCISCO, DEPT BIOPHYS, SAN FRANCISCO, CA 94143 USA.
NR 22
TC 2715
Z9 3324
U1 10
U2 419
PU NATURE PORTFOLIO
PI BERLIN
PA HEIDELBERGER PLATZ 3, BERLIN, 14197, GERMANY
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 461
EP 464
DI 10.1038/366461a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800063
PM 8247153
DA 2026-03-10
ER

PT J
AU BLACKMAN, DK
   ORCUTT, JA
   FORSYTH, DW
   KENDALL, JM
AF BLACKMAN, DK
   ORCUTT, JA
   FORSYTH, DW
   KENDALL, JM
TI SEISMIC ANISOTROPY IN THE MANTLE BENEATH AN OCEANIC SPREADING CENTER
SO NATURE
LA English
DT Article
ID mid-atlantic ridge; temperature; offset; zone; flow
AB BENEATH an active mid-ocean ridge, the mantle upwells in response to the divergence of the newly formed plates, leading to high temperatures and pressure-release melting below the ridge axis. The width of the upwelling region and the amount of melting depend on mantle rheology1-5, but all models predict a maximum decrease in seismic velocity at the ridge axis. It has also been suggested, however, that the alignment of anisotropic minerals by shear in the upwelling mantle will increase seismic velocity for rays travelling subvertically through the upwelling zone6,7. Here we report the observation of a consistent pattern of anomalously early P-wave arrival times at an array of ocean-bottom seismographs deployed across the axis of the southern Mid-Atlantic Ridge: P-waves from distant earthquakes arrive earlier at stations near the axis than at those further away. Our results are consistent with a model of anisotropy in which the degree of mineral alignment is greatest directly beneath the ridge axis, and significant anisotropy extends tens of kilometres from the axis.
C1 BROWN UNIV, DEPT GEOL SCI, PROVIDENCE, RI 02912 USA.
C3 Brown University
RP BLACKMAN, DK (corresponding author), UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, INST GEOPHYS & PLANETARY PHYS, LA JOLLA, CA 92093 USA.
NR 30
TC 33
Z9 34
U1 0
U2 2
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 16
PY 1993
VL 366
IS 6456
BP 675
EP 677
DI 10.1038/366675a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MM265
UT WOS:A1993MM26500066
DA 2026-03-10
ER

PT J
AU RAMAKRISHNAN, V
   FINCH, JT
   GRAZIANO, V
   LEE, PL
   SWEET, RM
AF RAMAKRISHNAN, V
   FINCH, JT
   GRAZIANO, V
   LEE, PL
   SWEET, RM
TI CRYSTAL-STRUCTURE OF GLOBULAR DOMAIN OF HISTONE H5 AND ITS IMPLICATIONS FOR NUCLEOSOME BINDING
SO NATURE
LA English
DT Article
ID gene activator protein; synchrotron radiation; anomalous dispersion; b-dna; chromatin; sequence; resolution; model; h-5; molecule
AB The structure of GH5, the globular domain of the linker histone H5, has been solved to 2.5 angstrom resolution by multiwavelength anomalous diffraction on crystals of the selenomethionyl protein. The structure shows a striking similarity to the DNA-binding domain of the catabolite gene activator protein CAP, thereby providing a possible model for the binding of GH5 to DNA.
C1 MRC,MOLEC BIOL LAB,CAMBRIDGE CB2 2QH,ENGLAND.
C3 MRC Laboratory Molecular Biology
RP RAMAKRISHNAN, V (corresponding author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA.
NR 47
TC 678
Z9 782
U1 0
U2 38
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 18
PY 1993
VL 362
IS 6417
BP 219
EP 223
DI 10.1038/362219a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KT026
UT WOS:A1993KT02600046
PM 8384699
DA 2026-03-10
ER

PT J
AU SHIDARA, M
   KAWANO, K
   GOMI, H
   KAWATO, M
AF SHIDARA, M
   KAWANO, K
   GOMI, H
   KAWATO, M
TI INVERSE-DYNAMICS MODEL EYE-MOVEMENT CONTROL BY PURKINJE-CELLS IN THE CEREBELLUM
SO NATURE
LA English
DT Article
ID ocular following responses; vestibuloocular reflex; primate flocculus; alert monkey
AB MANY lines of evidence suggest that the cerebellum is involved in motor control1.  But what features of these movements are encoded by cerebellar neurons? For slow-tracking eye movements, the activity of Purkinje cells in the ventral paraflocculus of the cerebellum is known to be correlated with eye velocity2-5 and acceleration5. Here we show that the complex temporal pattern of the firing frequency that occurs during the ocular following response elicited by movements of a large visual scene6-8 can be reconstructed by an inverse-dynamics representation, which uses the position, velocity and acceleration of eye movements. Further analysis reveals that the velocity and acceleration components can provide appropriate dynamic drive signals to ocular motor neurons, whereas the position component often has the wrong polarity. We conclude that these Purkinje cells primarily contribute dynamic command signals.
C1 ATR,HUMAN INFORMAT PROC RES LAB,KYOTO 61902,JAPAN.
   HOKKAIDO UNIV,ELECTR SCI RES INST,PARALLEL DISTRIBUTED PROC LAB,SAPPORO,HOKKAIDO 060,JAPAN.
C3 Hokkaido University
RP SHIDARA, M (corresponding author), ELECTROTECH LAB,NEUROSCI SECT,1-1-4 UMEZONO,TSUKUBA,IBARAKI 305,JAPAN.
NR 21
TC 257
Z9 285
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 50
EP 52
DI 10.1038/365050a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600051
PM 8361536
DA 2026-03-10
ER

PT J
AU MACCHIA, D
   ALMERIGOGNA, F
   PARRONCHI, P
   RAVINA, A
   MAGGI, E
   ROMAGNANI, S
AF MACCHIA, D
   ALMERIGOGNA, F
   PARRONCHI, P
   RAVINA, A
   MAGGI, E
   ROMAGNANI, S
TI MEMBRANE TUMOR-NECROSIS-FACTOR-ALPHA IS INVOLVED IN THE POLYCLONAL B-CELL ACTIVATION-INDUCED BY HIV-INFECTED HUMAN T-CELLS
SO NATURE
LA English
DT Article
ID acquired immunodeficiency syndrome; immune-deficiency syndrome; homosexual men; binding; clones
AB INFECTION of CD4+ T cells by human immune deficiency virus-1 (HIV-1) causes severe dysfunction of cellular immunity1-3, but paradoxically results in intense polyclonal activation of B cells, possibly accounting for both hypergammaglobulinaemia and frequent development of B-cell malignancies seen in HIV-infected patients4-7. We have reported that human CD4+ T-cell clones infected with HIV in vitro markedly stimulate immunoglobulin synthesis by B cells through a non-cognate, contact-dependent mechanism8. We show here that HIV-infected T-cell clones do not express the CD40 ligand (CD40L), a molecule critical for non-cognate B-cell activation9, but a small proportion of them do express membrane tumour-necrosis factor (TNF)-alpha. The ability of HIV-infected T-cell clones to induce polyclonal B-cell activation appears to be restricted to TNF-alpha-positive T blasts and is inhibited by antibodies against both TNF-alpha and TNF-alpha receptor. Freshly isolated CD4+ T cells from HIV-infected individuals express TNF-alpha on the cell membrane and induce TNF-alpha-mediated immunoglobulin production by B cells. Thus, membrane TNF-alpha seems to be involved in the polyclonal B-cell activation induced by HIV-infected T cells.
C1 UNIV FLORENCE,DIV CLIN IMMUNOL & ALLERGOL,VIALE MORGAGNI 85,I-50134 FLORENCE,ITALY.
   UNIV PISA,POLICLIN SANTA CHIARA,IST CLIN MED 1,I-56100 PISA,ITALY.
C3 University of Florence; University of Pisa
NR 17
TC 158
Z9 165
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 464
EP 466
DI 10.1038/363464a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800063
PM 7684824
DA 2026-03-10
ER

PT J
AU BORJA, M
   DUTTA, PK
AF BORJA, M
   DUTTA, PK
TI STORAGE OF LIGHT ENERGY BY PHOTOELECTRON TRANSFER ACROSS A SENSITIZED ZEOLITE SOLUTION INTERFACE
SO NATURE
LA English
DT Article
ID electron-transfer; hydrogen evolution; charge separation; reduction; complexes; molecules; acceptor; state; triad; cages
AB A COMMON strategy for storage of solar energy involves the photoexcitation of a donor molecule D followed by electron transfer to an acceptor A. To exploit this strategy in a practical context, a way must be found to impede the back-reaction in which the electron is transferred from A to D (ref. 1). Previous attempts to achieve long-lived charge separation have involved the use of D-A combinations held in well defined geometries by spacer groups2,3 or immobilized on supports such as porous media4-12. Immobilization of the redox species poses problems, however, for their subsequent separation in order to reclaim the stored energy. Here we report a system that achieves efficient D-A electron transfer, a slow back-reaction and easy separation of the products. We trap the photosensitizer donor, trisbipyridine ruthenium(II), in the supercages of zeolite Y, and use as the acceptor a neutral, zwitterionic viologen in the surrounding solution. Electron transfer from the ruthenium centre to the viologen is mediated by N,N'-tetramethylene-2,2'-bipyridinium ions loaded into the zeolite by ion exchange. Isolation of the donor within the zeolite from the acceptor in the solution outside makes the photochemically generated products easily accessible. Practical utilization of this trimolecular redox assembly will, however, require improvement of the quantum yield.
C1 OHIO STATE UNIV,DEPT CHEM,120 W 18TH AVE,COLUMBUS,OH 43210.
C3 University System of Ohio; Ohio State University
NR 23
TC 185
Z9 195
U1 0
U2 38
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAR 4
PY 1993
VL 362
IS 6415
BP 43
EP 45
DI 10.1038/362043a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KP976
UT WOS:A1993KP97600053
DA 2026-03-10
ER

PT J
AU STEVENS, CF
   WANG, YY
AF STEVENS, CF
   WANG, YY
TI REVERSAL OF LONG-TERM POTENTIATION BY INHIBITORS OF HEME OXYGENASE
SO NATURE
LA English
DT Article
ID dentate gyrus; transmission; hippocampus; zinc; rat
AB EVIDENCE that carbon monoxide can serve as an intercellular messenger in brain1-3, a role much like that demonstrated for nitric oxide in various tissues4, prompted us to investigate whether carbon monoxide participates in long-term potentiation (LTP), the cellular mechanism that may underlie certain forms of learning and memory. Although LTP is triggered in the postsynaptic neuron, at least some fraction of LTP is expressed presynaptically as an increase in the quantity of neurotransmitter released5-14. Thus, a retrograde signal must form the communication link between the postsynaptic site of induction and the presynaptic site of expression. To test whether carbon monoxide might act as a retrograde signal in LTP, we have investigated the effect on LTP of inhibitors of the enzyme haem oxygenase-2, which catalyses the production of carbon monoxide in the brain. We find that these inhibitors prevent the induction of LTP and have no effect on one form of long-term depression. Furthermore, they will reverse LTP that is already established.
RP STEVENS, CF (corresponding author), SALK INST BIOL STUDIES,HOWARD HUGHES MED INST,10010 N TORREY PINES RD,LA JOLLA,CA 92037, USA.
NR 23
TC 258
Z9 270
U1 1
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 147
EP 149
DI 10.1038/364147a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700049
PM 8321285
DA 2026-03-10
ER

PT J
AU FERREDAMARE, AR
   PRENDERGAST, GC
   ZIFF, EB
   BURLEY, SK
AF FERREDAMARE, AR
   PRENDERGAST, GC
   ZIFF, EB
   BURLEY, SK
TI RECOGNITION BY MAX OF ITS COGNATE DNA THROUGH A DIMERIC B/HLH/Z DOMAIN
SO NATURE
LA English
DT Article
ID loop-helix protein; c-myc; negative regulator; binding proteins; leucine zipper; transcription; motif; myod; refinement; enhancer
AB The three-dimensional structure of the basic/helix-loop-helix/leucine zipper domain of the transcription factor Max complexed with DNA has been determined by X-ray crystallography at 2.9 angstrom resolution. Max binds as a dimer to its recognition sequence CACGTG by direct contacts between the alpha-helical basic region and the major groove. This symmetric homodimer, a new protein fold, is a parallel, left-handed, four-helix bundle, with each monomer containing two alpha-helical segments separated by a loop. The two alpha-helical segments are composed of the basic region plus helix 1 and helix 2 plus the leucine repeat, respectively. As in GCN4, the leucine repeat forms a parallel coiled coil.
C1 ROCKEFELLER UNIV, MOLEC BIOPHYS LAB, 1230 YORK AVE, NEW YORK, NY 10021 USA.
   ROCKEFELLER UNIV, HOWARD HUGHES MED INST LAB, NEW YORK, NY 10021 USA.
   KAPLAN CANC CTR, DEPT BIOCHEM, NEW YORK, NY 10016 USA.
   NYU MED CTR, HOWARD HUGHES MED INST, NEW YORK, NY 10016 USA.
C3 Rockefeller University; Rockefeller University; Howard Hughes Medical Institute; New York University
NR 66
TC 660
Z9 734
U1 1
U2 32
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD MAY 6
PY 1993
VL 363
IS 6424
BP 38
EP 45
DI 10.1038/363038a0
PG 8
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LA682
UT WOS:A1993LA68200050
PM 8479534
DA 2026-03-10
ER

PT J
AU WARNE, PH
   VICIANA, PR
   DOWNWARD, J
AF WARNE, PH
   VICIANA, PR
   DOWNWARD, J
TI DIRECT INTERACTION OF RAS AND THE AMINO-TERMINAL REGION OF RAF-1 IN-VITRO
SO NATURE
LA English
DT Article
ID protein-kinase-c; signal transduction; binding; domain; gap; expression; activation; mutations; growth; cells
AB THE Ras proteins are key regulators of the growth of eukaryotic cells, but their direct target enzymes, or 'effectors', are unknown1. The protein encoded by the c-raf-1 proto-oncogene is thought to function downstream of p21ras because disruption of Raf blocks signalling by Ras in a number of systems2-5. Here we report that the amino-terminal cysteine-rich regulatory region of p74c-raf-1 expressed as a glutathione-S-transferase (GST) fusion protein binds directly to Ras with relatively high affinity (50 nM). The binding is strictly dependent on the Ras protein being in the active GTP-bound conformation rather than the inactive GDP-bound state. Raf-GST interacts with wild-type and oncogenic Ras (Val 12) but fails to interact with a biologically inert effector mutant of Ras (Ala 38) and a dominant negative mutant (Asn 17). A peptide based on the effector region of Ras inhibits the interaction. Raf-GST acts as a potent competitive inhibitor of the GTPase-activating proteins p120GAP and neurofibromin. In addition, Raf itself displays weak GTPase-stimulating activity towards Ras. It is therefore likely that Raf is a direct effector of Ras.
C1 IMPERIAL CANC RES FUND,44 LINCOLNS INN FIELDS,LONDON WC2A 3PX,ENGLAND.
C3 Cancer Research UK
NR 18
TC 683
Z9 766
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 352
EP 355
DI 10.1038/364352a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000062
PM 8332195
DA 2026-03-10
ER

PT J
AU GRINSPOON, DH
AF GRINSPOON, DH
TI IMPLICATIONS OF THE HIGH D/H RATIO FOR THE SOURCES OF WATER IN VENUS ATMOSPHERE
SO NATURE
LA English
DT Article
ID deuterium; hydrogen; escape; wet
AB THE high abundance ratio of deuterium to hydrogen in the atmosphere of Venus (120 times that on Earth) can be interpreted either as the signature of a lost primordial ocean1, or of a steady state in which water is continuously supplied to the surface of Venus by comets or volcanic outgassing, balancing loss through hydrogen escape2,3. New observations4-6 of a water concentration of only 30 parts per million in Venus' atmosphere imply that the residence time of water in the atmosphere, before it escapes to space, is short compared with the age of the Solar System, casting doubt on the primordial ocean hypothesis. But a recent theoretical reanalysis of collisional ejection7 has increased estimates of the deuterium escape efficiency by a factor of 10: this means that if the venusian water budget is in steady state, the D/H ratio of the source water must be 10-15 times higher than that on Earth, ruling out cometary water, whose D/H ratio is thought to be lower than this8. Here I suggest that these observations can be understood either as the result of continuous outgassing from a highly fractionated mantle source (such as might result from severe dessication of the mantle, or massive hydrogen escape early in the planet's history) or Rayleigh fractionation after massive outgassing from catastrophic resurfacing of the planet in the past 0.5-1 Gyr.
RP GRINSPOON, DH (corresponding author), UNIV COLORADO,ATMOSPHER & SPACE PHYS LAB,BOULDER,CO 80309, USA.
NR 21
TC 105
Z9 109
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 428
EP 431
DI 10.1038/363428a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800051
DA 2026-03-10
ER

PT J
AU SUCHYNA, TM
   XU, LX
   GAO, F
   FOURTNER, CR
   NICHOLSON, BJ
AF SUCHYNA, TM
   XU, LX
   GAO, F
   FOURTNER, CR
   NICHOLSON, BJ
TI IDENTIFICATION OF A PROLINE RESIDUE AS A TRANSDUCTION ELEMENT INVOLVED IN VOLTAGE GATING OF GAP-JUNCTIONS
SO NATURE
LA English
DT Article
AB GAP junction channels are structurally distinct from other ion channels in that they comprise two hemichannels which interact head-to-head to form an aqueous channel between cells. Intercellular voltage differences together with increased intracellular concentrations of H+ and Ca2+ cause closure of these normally patent channels1. The relative sensitivity to voltage varies with the subunit (connexin) composition of the channels2. The third of four transmembrane-spanning regions (M3) in connexins has been proposed to form the channel lining3, and a global 'tilting' of the hemichannel subunits has been correlated with channel closure4. But specific components involved in transduction of channel gating events have not been identified in either gap junctions or other ion channel classes (however, see model in ref. 5). We have examined a strictly conserved proline centrally located in M2 of connexin proteins. Mutation of this proline (Pro 87) in connexin 26 causes a reversal in the voltage-gating response when the mutant hemichannel is paired with wild-type connexin 26 in the Xenopus oocyte system. This suggests that the unique properties associated with this residue are critical to the transduction of voltage gating in these channels.
C1 SUNY BUFFALO,DEPT BIOL SCI,BUFFALO,NY 14260.
C3 State University of New York (SUNY) System; University at Buffalo, SUNY
NR 26
TC 140
Z9 151
U1 0
U2 2
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 28
PY 1993
VL 365
IS 6449
BP 847
EP 849
DI 10.1038/365847a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MD951
UT WOS:A1993MD95100053
PM 8413670
DA 2026-03-10
ER

PT J
AU GROOTES, PM
   STUIVER, M
   WHITE, JWC
   JOHNSEN, S
   JOUZEL, J
AF GROOTES, PM
   STUIVER, M
   WHITE, JWC
   JOHNSEN, S
   JOUZEL, J
TI COMPARISON OF OXYGEN-ISOTOPE RECORDS FROM THE GISP2 AND GRIP GREENLAND ICE CORES
SO NATURE
LA English
DT Article
AB RECENT results1,2 from the Greenland Ice-core Project (GRIP) Summit ice core suggest that the climate in Greenland has been remarkably stable during the Holocene, but was extremely unstable for the time period represented by the rest of the core, spanning the last two glaciations and the intervening Eemian interglacial. Here we present the complete oxygen isotope record for the Greenland Ice Sheet Project 2 (GISP2) core, drilled 28 km west of the GRIP core. We observe large, rapid climate fluctuations throughout the last glacial period, which closely match those reported for the GRIP core. However, in the bottom 10% of the cores, spanning the Eemian interglacial and the previous glaciation, there are significant differences between the two records. It is possible that ice flow may have altered the chronological sequences of the stratigraphy for the bottom part of one or both of the cores. Considerable further work will be necessary to evaluate the likelihood of this, and the extent to which it will still be possible to extract meaningful climate information from the lowest sections of the cores.
C1 UNIV WASHINGTON,QUATERNARY RES CTR,SEATTLE,WA 98195.
   UNIV COLORADO,INSTAAR,BOULDER,CO 80304.
   UNIV COPENHAGEN,NIELS BOHR INST,DEPT GEOPHYS,DK-2200 COPENHAGEN,DENMARK.
   UNIV ICELAND,INST SCI,DEPT GEOPHYS,IS-107 REYKJAVIK,ICELAND.
   CTR ETUD SACLAY,CEA,DSM,MODELISAT CLIMAT & ENVIRONM LAB,F-91191 GIF SUR YVETTE,FRANCE.
C3 University of Washington; University of Washington Seattle; University of Colorado System; University of Colorado Boulder; University of Copenhagen; Niels Bohr Institute; University of Iceland; CEA; Universite Paris Saclay
RP GROOTES, PM (corresponding author), UNIV WASHINGTON,DEPT GEOL SCI,SEATTLE,WA 98195, USA.
NR 19
TC 1529
Z9 1774
U1 1
U2 280
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD DEC 9
PY 1993
VL 366
IS 6455
BP 552
EP 554
DI 10.1038/366552a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA ML218
UT WOS:A1993ML21800065
DA 2026-03-10
ER

PT J
AU BURBANK, DW
   DERRY, LA
   FRANCELANORD, C
AF BURBANK, DW
   DERRY, LA
   FRANCELANORD, C
TI REDUCED HIMALAYAN SEDIMENT PRODUCTION 8 MYR AGO DESPITE AN INTENSIFIED MONSOON
SO NATURE
LA English
DT Article
ID northern hemisphere climate; southern asia; pakistan; ocean; magnetostratigraphy; plateau; uplift; west
AB UPLIFT of the Tibetan plateau about 7-8 Myr ago1,2 may have been responsible3-5 for the apparent intensification of the Asian monsoon6-10 around that time. Increases in the oceanic Sr-87/Sr-86 ratio during the Neogene period have been attributed11,12 to increased erosion from the Himalayan orogen. It has been suggested that the monsoonal intensification may have enhanced overall erosion rates in the region5,13. If this were the case, sediment accumulation rates would have increased in the surrounding basins at this time. Here we present a reanalysis of stratigraphic data from the Indo-Gangetic foreland and the Bengal fan, which demonstrates that both of these basins experienced a decline in sediment-accumulation rates 8 Myr ago. Thus it seems that monsoonal intensification was accompanied by a decrease in mechanical weathering. This decrease could be due to reduced tectonic activity, decreased Himalayan glaciation or slope stabilization from dense plant cover.
C1 HARTWICK COLL,DEPT CHEM,ONEONTA,NY 13820.
   CNRS,CRPG,F-54501 VANDOEUVRE NANCY,FRANCE.
C3 Universite de Lorraine; Centre National de la Recherche Scientifique (CNRS)
RP BURBANK, DW (corresponding author), UNIV SO CALIF,DEPT GEOL SCI,LOS ANGELES,CA 90089, USA.
NR 38
TC 142
Z9 168
U1 0
U2 25
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 48
EP 50
DI 10.1038/364048a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800052
DA 2026-03-10
ER

PT J
AU SLOANLANCASTER, J
   EVAVOLD, BD
   ALLEN, PM
AF SLOANLANCASTER, J
   EVAVOLD, BD
   ALLEN, PM
TI INDUCTION OF T-CELL ANERGY BY ALTERED T-CELL-RECEPTOR LIGAND ON LIVE ANTIGEN-PRESENTING CELLS
SO NATURE
LA English
DT Article
ID unresponsiveness; proliferation; stimulation; activation; clones; restimulation; molecules; occupancy; invitro; events
AB ACTIVATION of CD4+ T helper cells results from the occupancy of the T-cell receptor (TCR) by immunogenic peptide bound to a class II major histocompatibility complex (MHC) molecule1, together with a co-stimulatory signal from the antigen-presenting cell (APC)2. This activation leads to proliferation, cytokine production (Th1 or Th2 profile) and cytolysis3. Engagement of the TCR in the absence of co-stimulation causes Th1 cells to become unresponsive to subsequent antigenic stimulation4-6. We have previously demonstrated that analogues of an immunogenic peptide could stimulate Th1 and Th2 cells to carry out some effector functions without inducing proliferation7,25, a phenomenon we term partial activation. Here we study the consequences of such partial activation through the TCR of two Th1 clones using peptide analogues presented by a live APC. A peptide analogue that is unable to stimulate clonal proliferation or production of cytokine or inositol phosphate can induce the T cells to become profoundly unresponsive to subsequent stimulation with the immunogenic peptide. Thus, altering the ligand of the TCR by using a peptide analogue on a functional APC sends a signal to Th1 clones that results in anergy.
C1 WASHINGTON UNIV,SCH MED,DEPT PATHOL,660 S EUCLID,ST LOUIS,MO 63110.
C3 Washington University (WUSTL)
NR 26
TC 587
Z9 643
U1 0
U2 11
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD MAY 13
PY 1993
VL 363
IS 6425
BP 156
EP 159
DI 10.1038/363156a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LB801
UT WOS:A1993LB80100046
PM 8483498
DA 2026-03-10
ER

PT J
AU KELLERMANN, KI
AF KELLERMANN, KI
TI THE COSMOLOGICAL DECELERATION PARAMETER ESTIMATED FROM THE ANGULAR-SIZE REDSHIFT RELATION FOR COMPACT RADIO-SOURCES
SO NATURE
LA English
DT Article
ID luminosity
AB IN cosmological models based on the standard Friedmann-Robertson-Walker geometry, the apparent flux density or angular size of standard candles or standard rods varies with redshift in a way that depends on the deceleration parameter q0. (Open universes have q0 < 0.5; closed universes have q0 > 0.5.) At low redshift, however, observational errors are much greater than the differences in q0 expected for different cosmological models, while at high redshift observational uncertainties, particularly at optical wavelengths, and apparent systematic evolutionary changes in sources obscure the expected geometrical effects. Here I show that measurements by very-long-baseline interferometry (VLBI) of compact radio sources associated with active galaxies and quasars may be largely free of evolutionary effects even at substantial redshifts. The relation between angular size and redshift for a sample of these sources indicates a value of q0 close to 0.5, corresponding to cosmological density near the critical value.
RP KELLERMANN, KI (corresponding author), NATL RADIO ASTRON OBSERV,520 EDGEMENT RD,CHARLOTTESVILLE,VA 22903, USA.
NR 22
TC 145
Z9 151
U1 1
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 14
PY 1993
VL 361
IS 6408
BP 134
EP 136
DI 10.1038/361134a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KG466
UT WOS:A1993KG46600051
DA 2026-03-10
ER

PT J
AU LYONS, TW
   BERNER, RA
   ANDERSON, RF
AF LYONS, TW
   BERNER, RA
   ANDERSON, RF
TI EVIDENCE FOR LARGE PREINDUSTRIAL PERTURBATIONS OF THE BLACK-SEA CHEMOCLINE
SO NATURE
LA English
DT Article
ID sedimentary pyrite formation; iron; matter; sulfur
AB RECENT studies1-8 have documented significant short-term vertical fluctuations in the position of the oxic-anoxic interface (chemocline) in the waters of the Black Sea, the world's largest anoxic basin. Natural5,9 and anthropogenic3,4,8,10 influences have been invoked as possible causes of the observed fluctuations, but it has been difficult to establish the relative importance of these two forcings. One reason is that observations of the magnitude of chemocline displacement have not extended sufficiently far in the past to eliminate the possibility of anthropogenic changes in freshwater input. Here we present chemical analyses of shelf sediments, collected from the Bosporus region of the Black Sea, which contain a record of past water column chemistry. We find that the chemocline in this region rose by at least 40-50 m greater-than-or-equal-to 250-300 years ago, precluding anthropogenic forcing as a viable cause. Although our results do not rule out an anthropogenic cause for the recent variations, they do show that natural perturbations more than twice as large as the more recent changes have occurred in the past.
C1 YALE UNIV,DEPT GEOL & GEOPHYS,NEW HAVEN,CT 06520.
   COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964.
C3 Yale University; Columbia University
NR 30
TC 51
Z9 58
U1 0
U2 17
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD OCT 7
PY 1993
VL 365
IS 6446
BP 538
EP 540
DI 10.1038/365538a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MA661
UT WOS:A1993MA66100050
DA 2026-03-10
ER

PT J
AU MASSONNET, D
   ROSSI, M
   CARMONA, C
   ADRAGNA, F
   PELTZER, G
   FEIGL, K
   RABAUTE, T
AF MASSONNET, D
   ROSSI, M
   CARMONA, C
   ADRAGNA, F
   PELTZER, G
   FEIGL, K
   RABAUTE, T
TI THE DISPLACEMENT FIELD OF THE LANDERS EARTHQUAKE MAPPED BY RADAR INTERFEROMETRY
SO NATURE
LA English
DT Article
AB GEODETIC data, obtained by ground- or space-based techniques, can be used to infer the distribution of slip on a fault that has ruptured in an earthquake. Although most geodetic techniques require a surveyed network to be in Place before the earthquake1-3, satellite images, when collected at regular intervals, can capture co-seismic displacements without advance knowledge of the earthquake's location. Synthetic aperture radar (SAR) interferometry, first introduced4 in 1974 for topographic mapping5-8 can also be used to detect changes in the ground surface, by removing the signal from the topography9,10. Here we use SAR interferometry to capture the movements produced by the 1992 earthquake in Landers, California11. We construct an interferogram by combining topographic information with SAR images obtained by the ERS-1 satellite before and after the earthquake. The observed changes in range from the ground surface to the satellite agree well with the slip measured in the field, with the displacements measured by surveying, and with the results of an elastic dislocation model. As a geodetic tool, the SAR interferogram provides a denser spatial sampling (100 m per pixel) than surveying methods1-3 and a better precision (approximately 3 cm) than previous space imaging techniques12,13.
C1 OBSERV MIDI PYRENEES,F-31400 TOULOUSE,FRANCE.
   SCOT CONSEIL,F-31520 RAMONVILLE,FRANCE.
C3 Universite de Toulouse; Universite Toulouse III - Paul Sabatier
RP MASSONNET, D (corresponding author), CTR NATL ETUD SPATIALES,18 AVE E BELIN,F-31055 TOULOUSE,FRANCE.
NR 26
TC 1696
Z9 2065
U1 16
U2 251
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 138
EP 142
DI 10.1038/364138a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700046
DA 2026-03-10
ER

PT J
AU TAN, SS
   BREEN, S
AF TAN, SS
   BREEN, S
TI RADIAL MOSAICISM AND TANGENTIAL CELL DISPERSION BOTH CONTRIBUTE TO MOUSE NEOCORTICAL DEVELOPMENT
SO NATURE
LA English
DT Article
ID cerebral-cortex; somatosensory cortex; migration patterns; visual-cortex; thalamus; projections; neurons; lineage; rhesus
AB THE mammalian neocortex is generated by waves of migrating cells originating from the ventricular Zone1,2. Radial migration3 along radial glia4,5 has been proposed as the dominant mechanism for this process. The radial unit hypothesis3 is poorly supported by retroviral lineage studies, however, and although some clones show limited radial organization6, the emphasis appears to be on widespread tangential dispersion7-10. Here we investigate the pattern of cortical cell dispersion using transgenic mice in which roughly half of the brain cells are coloured by a transgene11. We find that the neocortex is randomly divided into diffused bands, the majority of cells within each band have the same colour, and their radial orientation suggests radial dispersion. Superimposed upon this was a significant contribution by tangentially dispersed cells that did not respect clonal borders. These observations indicate that cortical specification is not dependent upon a single mechanism of cell allocation, but that both radial mosaicism and tangential cell migration are involved.
RP TAN, SS (corresponding author), UNIV MELBOURNE,DEPT ANAT & CELL BIOL,EMBRYOL LAB,PARKVILLE,VIC 3052,AUSTRALIA.
NR 18
TC 175
Z9 188
U1 0
U2 3
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 638
EP 640
DI 10.1038/362638a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800050
PM 8464515
DA 2026-03-10
ER

PT J
AU SLESAREV, AI
   STETTER, KO
   LAKE, JA
   GELLERT, M
   KRAH, R
   KOZYAVKIN, SA
AF SLESAREV, AI
   STETTER, KO
   LAKE, JA
   GELLERT, M
   KRAH, R
   KOZYAVKIN, SA
TI DNA TOPOISOMERASE-V IS A RELATIVE OF EUKARYOTIC TOPOISOMERASE-I FROM A HYPERTHERMOPHILIC PROKARYOTE
SO NATURE
LA English
DT Article
ID desulfurococcus-amylolyticus; methanopyrus-kandleri; archaebacteria; 110-degrees-c; methanogens; archaea; gene
AB THE DNA topoisomerases are ubiquitous enzymes that fulfil vital roles in the replication, transcription and recombination of DNA by carrying out DNA-strand passage reactions1-7. Here we characterize a prokaryotic counterpart to the eukaryotic topoisomerase I in the hyperthermophilic methanogen Methanopyrus kandleri8-10. The new enzyme, called topoisomerase V, has the following properties in common with eukaryotic topoisomerase I, which distinguish it from all other known prokaryotic topoisomerases: (1) its activity is Mg2+-independent; (2) it relaxes both negatively and positively supercoiled DNA; (3) it makes a covalent complex with the 3' end of the broken DNA strand; and (4) it is recognized by antibody raised against human topoisomerase I. Eukaryotic-like enzymes have been discovered in some hyperthermophilic prokaryotes, namely the eocytes11 and the extremely thermophilic archaebacteria12, and hyperthermophilic homologues of eukaryotic DNA polymerase-a, transcription factor IIB and DNA ligase13-15 have all been reported. Thus our findings support the idea that some essential parts of the eukaryotic transcription-translation and replication machineries were in place before the emergence of eukaryotes, and that the closest living relatives of eukaryotes may be hyperthermophiles.
C1 RUSSIAN ACAD SCI,INST MOLEC GENET,MOSCOW 123182,RUSSIA.
   UKRAINIAN ACAD SCI,RE KAVETSKY INST ONCOL & RADIOBIOL,KIEV 252127,UKRAINE.
   UNIV CALIF LOS ANGELES,DEPT BIOL,LOS ANGELES,CA 90024.
   UNIV REGENSBURG,LEHRSTUHL MIKROBIOL,W-8400 REGENSBURG,GERMANY.
   NIDDK,MOLEC BIOL LAB,BETHESDA,MD 20892.
C3 Russian Academy of Sciences; National Academy of Sciences Ukraine; University of California System; University of California Los Angeles; University of Regensburg; National Institutes of Health (NIH) - USA; NIH National Institute of Diabetes & Digestive & Kidney Diseases (NIDDK)
RP SLESAREV, AI (corresponding author), UNIV CALIF LOS ANGELES,INST MOLEC BIOL,LOS ANGELES,CA 90024, USA.
NR 21
TC 85
Z9 114
U1 0
U2 22
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 19
PY 1993
VL 364
IS 6439
BP 735
EP 736
DI 10.1038/364735a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LT677
UT WOS:A1993LT67700064
PM 8395022
DA 2026-03-10
ER

PT J
AU DESAI, SA
   KROGSTAD, DJ
   MCCLESKEY, EW
AF DESAI, SA
   KROGSTAD, DJ
   MCCLESKEY, EW
TI A NUTRIENT-PERMEABLE CHANNEL ON THE INTRAERYTHROCYTIC MALARIA PARASITE
SO NATURE
LA English
DT Article
ID host-cell membrane; plasmodium-falciparum; mitochondrial-membrane; erythrocytic stages; precursors; transport; pathway; culture
AB DURING its 48-hour cycle inside the red blood cell, the human malaria parasite, Plasmodium falciparum, increases its volume 25-fold and divides asexually. This rapid growth demands large amounts of nutrients, a problem exacerbated by the lower metabolic rate and relative ionic impermeability of the host red blood cell. Direct passage of small nutrients across the two membranes that separate the parasite from the erythrocyte cytosol may be important for parasite development, and has been demonstrated for radiolabelled glucose2, amino acids3,4 and purine nucleosides4-6. Flux studies on plasmodia are limited, however, to suspensions of erythrocyte-free parasites and so cannot be used to examine the individual transport properties of the two membranes involved. Here we use the cell-attached patch clamp method7 to overcome this limitation. After removing the intervening red blood cell membrane and forming gigaohm seals on the small (3-5 mum) parasite, we studied transport across the parasitophorous vacuole membrane (PVM), the outer of the two membranes that separate the parasite from the erythrocyte cytosol. A 140-pS channel which is permeable to both cations and anions was identified on the PVM. This channel is present at high density, is open more than 98 per cent of the time at the resting potential of the PVM, and is permeable to lysine and glucuronate. The channel can readily transport amino acids and monosaccharides across the PVM and may be essential for fulfilling the parasite's metabolic demands.
C1 WASHINGTON UNIV,DEPT CELL BIOL,ST LOUIS,MO 63110.
   WASHINGTON UNIV,DEPT MED,ST LOUIS,MO 63110.
   WASHINGTON UNIV,DEPT PATHOL,ST LOUIS,MO 63110.
   WASHINGTON UNIV,DEPT MECH ENGN,ST LOUIS,MO 63110.
C3 Washington University (WUSTL); Washington University (WUSTL); Washington University (WUSTL); Washington University (WUSTL)
NR 29
TC 186
Z9 216
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 15
PY 1993
VL 362
IS 6421
BP 643
EP 646
DI 10.1038/362643a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KX438
UT WOS:A1993KX43800052
PM 7681937
DA 2026-03-10
ER

PT J
AU WAGNER, H
   FROST, B
AF WAGNER, H
   FROST, B
TI DISPARITY-SENSITIVE CELLS IN THE OWL HAVE A CHARACTERISTIC DISPARITY
SO NATURE
LA English
DT Article
ID cats visual-cortex; interaural time difference; barn owl; binocular organization; brain-stem; neurons; telencephalon; wulst; depth
AB WE experience the visual world as being three-dimensional. A major source of depth information derives from the slightly different views of each eye, leading to small variations in the retinal images ('disparities'). Neurons sensitive to visual disparities are thought to form the neural basis of stereo vision1-10. Barn owls2,3 as well as several mammalian species1,4-10 have neurons that are sensitive to visual disparities. But how visual disparities are represented in the brain has been a matter of discussion ever since the first disparity-sensitive neurons were found some 25 years ago. Here we adopt a new approach to this problem and study the neural computation of visual disparities with a paradigm borrowed from auditory research. The measurement of interaural time difference (ITD) has many similarities with the measurement of visual disparity on the formal, algorithmic level. We speculate that the similarities might extend to the level of neural computation. The neural representation of ITD is well understood11-18, and we have studied the representation of disparities with visual stimuli analogous to those successfully used in acoustic experiments. For example, ITD is converted in the brain to a pathlength on an axon that, owing to the finite conduction velocity in neurons, exactly matches the external ITD. This pathlength is called 'characteristic delay,12. Our results suggest that there is an analogue of the characteristic delay in stereo vision which we propose to call 'characteristic disparity'.
C1 MAX PLANCK INST BIOL CYBERNET,D-72076 TUBINGEN,GERMANY.
C3 Max Planck Society
RP WAGNER, H (corresponding author), QUEENS UNIV,DEPT PSYCHOL,KINGSTON K7L 3N6,ONTARIO,CANADA.
NR 27
TC 54
Z9 55
U1 0
U2 5
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 26
PY 1993
VL 364
IS 6440
BP 796
EP 798
DI 10.1038/364796a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LU581
UT WOS:A1993LU58100054
PM 8355804
DA 2026-03-10
ER

PT J
AU JONES, M
   SAUNDERS, R
   ALEXANDER, P
   BIRKINSHAW, M
   DILLON, N
   GRAINGE, K
   HANCOCK, S
   LASENBY, A
   LEFEBVRE, D
   POOLEY, G
   SCOTT, P
   TITTERINGTON, D
   WILSON, D
AF JONES, M
   SAUNDERS, R
   ALEXANDER, P
   BIRKINSHAW, M
   DILLON, N
   GRAINGE, K
   HANCOCK, S
   LASENBY, A
   LEFEBVRE, D
   POOLEY, G
   SCOTT, P
   TITTERINGTON, D
   WILSON, D
TI AN IMAGE OF THE SUNYAEV-ZELDOVICH EFFECT
SO NATURE
LA English
DT Article
ID 3 clusters; abell-2218; galaxy; h0
AB THE Sunyaev-Zel'dovich effect1 is a distortion imposed on the 2.7-K cosmic microwave background radiation when the microwave photons are scattered by the hot gas in galaxy clusters. At radio wavelengths it appears as a decrement (of about 0.5 mK) in the brightness temperature of the background radiation. Measurements of this effect can provide information about the physics of galaxy clusters, and can also potentially be used to determine the Hubble constant, by constraining the size of the cluster along the line of sight. Successful detections have been made with single-dish radio telescopes2,3, from which one-dimensional profiles of the temperature decrement are constructed. But these observations are susceptible to several systematic errors, such as corruption of the measured signal by radio sources located close to the line of sight. To circumvent these problems, we have obtained a two-dimensional image, using an interferometric (rather than single-dish) approach, of structure in the microwave background in the vicinity of the galaxy cluster Abell 2218. Our measurements, combined with X-ray observations of the scattering gas in the same cluster, support a low value of the Hubble constant.
RP JONES, M (corresponding author), MULLARD RADIO ASTRON OBSERV, CAVENDISH LAB, MADINGLEY RD, CAMBRIDGE CB3 0HE, ENGLAND.
NR 17
TC 134
Z9 137
U1 0
U2 1
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 23
PY 1993
VL 365
IS 6444
BP 320
EP 323
DI 10.1038/365320a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LY496
UT WOS:A1993LY49600044
DA 2026-03-10
ER

PT J
AU MULLAART, E
   DEVOS, GJ
   MEERMAN, GJT
   UITTERLINDEN, AG
   VIJG, J
AF MULLAART, E
   DEVOS, GJ
   MEERMAN, GJT
   UITTERLINDEN, AG
   VIJG, J
TI PARALLEL GENOME ANALYSIS BY 2-DIMENSIONAL DNA TYPING
SO NATURE
LA English
DT Article
ID electrophoresis; proteins
C1 UNIV GRONINGEN,DEPT MED GENET,9713 AW GRONINGEN,NETHERLANDS.
C3 University of Groningen
RP MULLAART, E (corresponding author), INGENY BV,POB 685,2300 AR LEIDEN,NETHERLANDS.
NR 10
TC 23
Z9 23
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 469
EP 471
DI 10.1038/365469a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300068
PM 8413593
DA 2026-03-10
ER

PT J
AU WITHERS, GS
   FAHRBACH, SE
   ROBINSON, GE
AF WITHERS, GS
   FAHRBACH, SE
   ROBINSON, GE
TI SELECTIVE NEUROANATOMICAL PLASTICITY AND DIVISION-OF-LABOR IN THE HONEYBEE
SO NATURE
LA English
DT Article
ID mushroom body; apis-mellifera; synaptogenesis; morphology; cortex; brain; bee
AB THE mushroom bodies in the protocerebrum are believed to be the structures of the insect brain most closely associated with higher-order sensory integration and learning1. Drosophila melanogaster mutants with olfactory learning deficit have anatomically abnormal mushroom bodies or altered patterns of gene expression in mushroom body neurons2-4. In addition, anatomical reorganization of the mushroom bodies occurs in adult flies5, and possibly in adult honeybees6,7; disturbance of electrical activity in this region disrupts memory formation in honeybees8. Little is known, however, about the relationship of naturally occurring anatomical changes in the mushroom bodies to naturally occurring behavioural plasticity. We now report that age-based division of labour in adult worker honeybees (Apis mellifera) is associated with substantial changes in certain brain regions, notably the mushroom bodies. Moreover, these striking changes in brain structure are dependent, not on the age of the bee, but on its foraging experience, thus demonstrating a robust anatomical plasticity associated with complex behaviour in an adult insect.
C1 UNIV ILLINOIS,DEPT ENTOMOL,URBANA,IL 61801.
C3 University of Illinois System; University of Illinois Urbana-Champaign
RP WITHERS, GS (corresponding author), UNIV ILLINOIS,NEUROSCI PROGRAM,URBANA,IL 61801, USA.
NR 27
TC 343
Z9 375
U1 0
U2 46
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 238
EP 240
DI 10.1038/364238a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300057
PM 8321320
DA 2026-03-10
ER

PT J
AU DISANTO, JP
   BONNEFOY, JY
   GAUCHAT, JF
   FISCHER, A
   DESAINTBASILE, G
AF DISANTO, JP
   BONNEFOY, JY
   GAUCHAT, JF
   FISCHER, A
   DESAINTBASILE, G
TI CD40 LIGAND MUTATIONS IN X-LINKED IMMUNODEFICIENCY WITH HYPER-IGM
SO NATURE
LA English
DT Article
ID tumor necrosis factor; hyperimmunoglobulinemia-m; switch; receptor; cloning; cells
AB SIGNALLING for the B-cell immunoglobulin isotype switch requires T-cell-derived cytokines and T-B cell interaction, which operates primarily through the CD40 molecule on B cells with its ligand (CD40L) on activated T cells (reviewed in ref. 1). The CD40L is a type II membrane protein2-5 with homology to tumour necrosis factor-alpha and -beta6,7, and has important functions in B-cell activation and differentiation2,4,8. Human CD40L maps on Xq26.3-27.1 (ref. 3), the region where a primary immunodeficiency characterized by an immunoglobulin isotype switch defect (the hyper-IgM immunodeficiency syndrome, HIGM1) has been localized9,10. The hypothesis that HIGM1 involves an abnormality of the CD40L has been tested. We report here the lack of CD40L expression in four unrelated male children with the hyper-IgM syndrome. CD40L transcripts in these patients showed either deletions or point mutations clustered within a limited region of the CD40L. extracellular domain. These genetic alterations with abnormal CD40L expression provide a molecular basis for immunoglobulin isotype switch defects observed in this immunodeficiency.
C1 GLAXO INST MOLEC BIOL,GENEVA 674,SWITZERLAND.
C3 GlaxoSmithKline; GlaxoSmithKline Switzerland
RP DISANTO, JP (corresponding author), HOP NECKER ENFANTS MALAD,INSERM,U132,149 RUE SEVRES,F-75743 PARIS 15,FRANCE.
NR 21
TC 656
Z9 706
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD FEB 11
PY 1993
VL 361
IS 6412
BP 541
EP 543
DI 10.1038/361541a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KL714
UT WOS:A1993KL71400062
PM 8094231
DA 2026-03-10
ER

PT J
AU PFENNIG, DW
   COLLINS, JP
AF PFENNIG, DW
   COLLINS, JP
TI KINSHIP AFFECTS MORPHOGENESIS IN CANNIBALISTIC SALAMANDERS
SO NATURE
LA English
DT Article
ID ambystoma-tigrinum-nebulosum; tiger salamanders; competition
AB INCLUSIVE fitness theory predicts that organisms can often increase their fitness by helping relatives1. Indeed, many animals modify their behaviour towards kin in a fashion consistent with theory2-4. Morphogenesis may also be sensitive to kinship environment, especially in species that facultatively produce distinct morphs that differ in their ability to harm relatives, such as those that produce alternative cannibalistic and non-cannibalistic phenotypes5-9. We tested this hypothesis by examining whether consanguinity affected the probability that structurally distinctive cannibal morphs5,10 would develop in larval Arizona tiger salamanders (Ambystoma tigrinum nebulosum). We report here that when tiger salamander larvae are reared in mixed-brood groups they are significantly more likely to develop the cannibal morphology and at an earlier age than siblings reared in pure-sibship groups. In general, morphogenesis may be responsive to kinship in any species that facultatively develops structures that can be used against conspecifics as weaponry.
C1 ARIZONA STATE UNIV,DEPT ZOOL,TEMPE,AZ 85287.
C3 Arizona State University; Arizona State University-Tempe
RP PFENNIG, DW (corresponding author), CORNELL UNIV,NEUROBIOL & BEHAV SECT,MUDD HALL,ITHACA,NY 14853, USA.
NR 27
TC 98
Z9 115
U1 0
U2 26
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD APR 29
PY 1993
VL 362
IS 6423
BP 836
EP 838
DI 10.1038/362836a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KZ563
UT WOS:A1993KZ56300055
PM 8479520
DA 2026-03-10
ER

PT J
AU TINGLEY, WG
   ROCHE, KW
   THOMPSON, AK
   HUGANIR, RL
AF TINGLEY, WG
   ROCHE, KW
   THOMPSON, AK
   HUGANIR, RL
TI REGULATION OF NMDA RECEPTOR PHOSPHORYLATION BY ALTERNATIVE SPLICING OF THE C-TERMINAL DOMAIN
SO NATURE
LA English
DT Article
ID acetylcholine-receptor; protein-kinase; sequences
AB THE NMDA (N-methyl D-aspartate) receptors in the brain play a critical role in synaptic plasticity, synaptogenesis and excitotoxicity1-3. Molecular cloning has demonstrated that NMDA receptors consist of several homologous subunits (NMDAR1, 2A-2D)4-7. A variety of studies have suggested that protein phosphorylation of NMDA receptors may regulate their function7-12 and play a role in many forms of synaptic plasticity such as long-term potentiation13,14. We have examined the phosphorylation of the NMDA receptor subunit NMDAR1 (NR1) by protein kinase C (PKC) in cells transiently expressing recombinant NR1 and in primary cultures of cortical neurons. PKC phosphorylation occurs on several distinct sites on the NR1 subunit. Most of these sites are contained within a single alternatively spliced exon in the C-terminal domain, which has previously been proposed to be on the extracellular side of the membrane4,5,15. These results demonstrate that alternative splicing of the NR1 messenger RNA regulates its phosphorylation by PKC, and that mRNA splicing is a novel mechanism for regulating the sensitivity of glutamate receptors to protein phosphorylation. These results also provide evidence that the C-terminal domain of the NR1 protein is located intracellularly, suggesting that the proposed transmembrane topology model for glutamate receptors may be incorrect.
C1 JOHNS HOPKINS UNIV,SCH MED,HOWARD HUGHES MED INST,DEPT NEUROSCI,BALTIMORE,MD 21205.
C3 Howard Hughes Medical Institute; Johns Hopkins University
NR 28
TC 377
Z9 414
U1 0
U2 6
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 1
PY 1993
VL 364
IS 6432
BP 70
EP 73
DI 10.1038/364070a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LK818
UT WOS:A1993LK81800060
PM 8316301
DA 2026-03-10
ER

PT J
AU DANSGAARD, W
   JOHNSEN, SJ
   CLAUSEN, HB
   DAHLJENSEN, D
   GUNDESTRUP, NS
   HAMMER, CU
   HVIDBERG, CS
   STEFFENSEN, JP
   SVEINBJORNSDOTTIR, AE
   JOUZEL, J
   BOND, G
AF DANSGAARD, W
   JOHNSEN, SJ
   CLAUSEN, HB
   DAHLJENSEN, D
   GUNDESTRUP, NS
   HAMMER, CU
   HVIDBERG, CS
   STEFFENSEN, JP
   SVEINBJORNSDOTTIR, AE
   JOUZEL, J
   BOND, G
TI EVIDENCE FOR GENERAL INSTABILITY OF PAST CLIMATE FROM A 250-KYR ICE-CORE RECORD
SO NATURE
LA English
DT Article
ID greenland
AB RECENT results1,2 from two ice cores drilled in central Greenland have revealed large, abrupt climate changes of at least regional extent during the late stages of the last glaciation, suggesting that climate in the North Atlantic region is able to reorganize itself rapidly, perhaps even within a few decades. Here we present a detailed stable-isotope record for the full length of the Greenland Ice-core Project Summit ice core, extending over the past 250 kyr according to a calculated timescale. We find that climate instability was not confined to the last glaciation, but appears also to have been marked during the last interglacial (as explored more fully in a companion paper3) and during the previous Saale-Holstein glacial cycle. This is in contrast with the extreme stability of the Holocene, suggesting that recent climate stability may be the exception rather than the rule. The last interglacial seems to have lasted longer than is implied by the deep-sea SPECMAP record4, in agreement with other land-based observations5,6. We suggest that climate instability in the early part of the last interglacial may have delayed the melting of the Saalean ice sheets in America and Eurasia, perhaps accounting for this discrepancy.
C1 UNIV ICELAND, DEPT GEOPHYS, INST SCI, IS-107 REYKJAVIK, ICELAND.
   CTR ETUD SACLAY, DSM, CEA, MODELISAT CLIMAT & ENVIRONM LAB, F-91191 GIF SUR YVETTE, FRANCE.
   LAB GLACIOL & GEOPHYS ENVIRONM, F-38402 ST MARTIN DHERES, FRANCE.
   COLUMBIA UNIV, LAMONT DOHERTY GEOL OBSERV, PALISADES, NY 10964 USA.
C3 University of Iceland; Universite Paris Saclay; CEA; Columbia University
RP DANSGAARD, W (corresponding author), UNIV COPENHAGEN, NIELS BOHR INST, DEPT GEOPHYS, HARALDSGADE 6, DK-2200 COPENHAGEN, DENMARK.
NR 26
TC 3605
Z9 4171
U1 14
U2 787
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 218
EP 220
DI 10.1038/364218a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300050
DA 2026-03-10
ER

PT J
AU WEAVER, PPE
   THOMSON, J
AF WEAVER, PPE
   THOMSON, J
TI CALCULATING EROSION BY DEEP-SEA TURBIDITY CURRENTS DURING INITIATION AND FLOW
SO NATURE
LA English
DT Article
AB TURBIDITY currents transport massive amounts of sediment from continental margins to the deep sea. Individual flows can catastrophically remove and redeposit (as turbidites) many hundreds of cubic kilometres of material1,2, with the larger events reaching the bottom of the continental slope to form the abyssal plains3. Here we show that the age range of sediments in individual turbidites can be used directly to estimate both the thickness of failed sediment in the source region (even when its exact location is unknown) and the extent to which the turbidity current caused erosion of the sea bed. Our method involves the comparison of the abundance ratios of microfossil (coccolith) species in turbidites with those in the ocean margin sediments of the source region. Analysis of a recently emplaced turbidite on the Madeira Abyssal Plain shows that it contains a mixture of sediments with an age range of about 200,000 years, equivalent to the failure of a block of sediment about 15 m deep. Radiocarbon dating and coccolith ratios show that the turbidite contains only about 12% of recent, near-surface sediment, indicating that this turbidity current caused surprisingly little erosion en route.
RP WEAVER, PPE (corresponding author), INST OCEANOG SCI,DEACON LAB,BROOK RD,GODALMING GU8 5UB,SURREY,ENGLAND.
NR 22
TC 53
Z9 56
U1 2
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 136
EP 138
DI 10.1038/364136a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700045
DA 2026-03-10
ER

PT J
AU SHEN, Y
   SAFINYA, CR
   LIANG, KS
   RUPPERT, AF
   ROTHSCHILD, KJ
AF SHEN, Y
   SAFINYA, CR
   LIANG, KS
   RUPPERT, AF
   ROTHSCHILD, KJ
TI STABILIZATION OF THE MEMBRANE-PROTEIN BACTERIORHODOPSIN TO 140-DEGREES-C IN 2-DIMENSIONAL FILMS
SO NATURE
LA English
DT Article
ID purple membrane; x-ray; halobacterium-halobium; electron-microscopy; thermal-stability; model; lipids; helix
AB TWO-DIMENSIONAL assemblies of membrane proteins (see ref. 1, for example) such as bacteriorhodopsin are of current interest because of their potential application in technological areas as diverse as molecular electronics and optical switching2, molecular sieves3,4 and the lithographic fabrication of nanometre-scale patterns5,6. Here we report that bacteriorhodopsin7-9 can retain its folded native structure to temperatures as high as 140-degrees-C when incorporated in multilayer structures of self-assembled, ordered films. Synchrotron X-ray scattering reveals that, under hydrated conditions, the two-dimensional lattice in multilayer films exhibits a reversible solid-liquid transition at about 69-degrees-C, followed by irreversible denaturing of the bacteriorhodopsin at about 90-degrees-C. But in dry films the melting transition and denaturation are suppressed up to 140-degrees-C. These results suggest that it may be feasible to use multilayer assemblies of functional proteins and enzymes10,11 in high-temperature applications.
C1 UNIV CALIF SANTA BARBARA,DEPT MAT,SANTA BARBARA,CA 93106.
   UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106.
   UNIV CALIF SANTA BARBARA,MAT RES LAB,SANTA BARBARA,CA 93106.
   EXXON RES & ENGN CO,ANNANDALE,NJ 08801.
   BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215.
   BOSTON UNIV,DEPT PHYSIOL,BOSTON,MA 02215.
C3 University of California System; University of California Santa Barbara; University of California System; University of California Santa Barbara; University of California System; University of California Santa Barbara; Exxon Mobil Corporation; Boston University; Boston University
NR 29
TC 157
Z9 165
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD NOV 4
PY 1993
VL 366
IS 6450
BP 48
EP 50
DI 10.1038/366048a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MF007
UT WOS:A1993MF00700049
DA 2026-03-10
ER

PT J
AU HOLZ, GG
   KUHTREIBER, WM
   HABENER, JF
AF HOLZ, GG
   KUHTREIBER, WM
   HABENER, JF
TI PANCREATIC BETA-CELLS ARE RENDERED GLUCOSE-COMPETENT BY THE INSULINOTROPIC HORMONE GLUCAGON-LIKE PEPTIDE-1(7-37)
SO NATURE
LA English
DT Article
ID electrical-activity; b-cells; gene-expression; ca-2+ channels; protein-kinase; atp; currents; release; activation; modulation
AB NON-INSULIN-DEPENDENT diabetes mellitus (NIDDM, type 2 diabetes) is a disorder of glucose homeostasis characterized by hyperglycaemia, peripheral insulin resistance, impaired hepatic glucose metabolism, and diminished glucose-dependent secretion of insulin from pancreatic beta-cells1. Glucagon-like-peptide-1(7-37) (GLP-1)2 is an intestinally derived hormone that may be useful for the treatment of NIDDM because it acts in vivo to increase the level of circulating insulin, and thus lower the concentration of blood glucose3,4. This therapeutic effect may result from the ability of GLP-1 to compensate for a defect in the glucose signalling pathway that regulates insulin secretion from beta-cells. In support of this concept we report here that GLP-1 confers glucose sensitivity to glucose-resistant beta-cells, a phenomenon we term glucose competence. Induction of glucose competence by GLP-1 results from its synergistic interaction with glucose to inhibit metabolically regulated potassium channels that are also targeted for inhibition by sulphonylurea drugs commonly used in the treatment of NIDDM5. Glucose competence allows membrane depolarization, the generation of action potentials, and Ca2+ influx, events that are known to trigger insulin secretion6,7.
RP HOLZ, GG (corresponding author), HARVARD UNIV,MASSACHUSETTS GEN HOSP,SCH MED,HOWARD HUGHES MED INST,MOLEC ENDOCRINOL LAB,BOSTON,MA 02114, USA.
FU NIDDK NIH HHS [R01 DK045817] Funding Source: Medline
NR 32
TC 507
Z9 591
U1 0
U2 18
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JAN 28
PY 1993
VL 361
IS 6410
BP 362
EP 365
DI 10.1038/361362a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA KJ590
UT WOS:A1993KJ59000061
PM 8381211
DA 2026-03-10
ER

PT J
AU SCHLAGGAR, BL
   FOX, K
   OLEARY, DDM
AF SCHLAGGAR, BL
   FOX, K
   OLEARY, DDM
TI POSTSYNAPTIC CONTROL OF PLASTICITY IN DEVELOPING SOMATOSENSORY CORTEX
SO NATURE
LA English
DT Article
ID receptor antagonists disrupt; striate cortex; blockade prevents; cortical activity; nmda receptors; visual-cortex; rat; acetylcholinesterase; period; axons
AB THE rearrangement of synaptic connections during normal and deprived development is thought to be controlled by correlations in afferent impulse activity1. A favoured model is based on postsynaptic detection of synchronously active afferents; synapses are stabilized when pre- and postsynaptic activity is correlated and weakened or eliminated when their activity is uncorrelated2,3. Most evidence for this model comes from demonstrations that correlated afferent input is necessary for the segregation of eye-dominant inputs in the developing vertebrate visual system1,4,5 and that critical period plasticity of ocular dominance columns in cat visual cortex is disrupted by blockade of postsynaptic transmission6-8. We tested whether the developmental plasticity of somatosensory columns, known as 'barrels', in rodent primary somatosensory cortex (S1)9-13 is similar to that of ocular dominance columns. We report here that the selective disruption of postsynaptic activation in rat S1 by application of a glutamate receptor antagonist inhibits rearrangements in the somatotopic patterning of thalamocortical afferents induced by manipulations of the sensory periphery during the critical period. These findings show that postsynaptic activation has a prominent role in critical period plasticity in S1 cortex.
C1 SALK INST BIOL STUDIES,MOLEC NEUROBIOL LAB,10010 N TORREY PINES RD,LA JOLLA,CA 92037.
   UNIV MINNESOTA,DEPT PHYSIOL,MINNEAPOLIS,MN 55455.
C3 Salk Institute; University of Minnesota System; University of Minnesota Twin Cities
NR 30
TC 283
Z9 301
U1 0
U2 0
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD AUG 12
PY 1993
VL 364
IS 6438
BP 623
EP 626
DI 10.1038/364623a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LR771
UT WOS:A1993LR77100052
PM 8102476
DA 2026-03-10
ER

PT J
AU LEIBSLE, FM
   MURRAY, PW
   FRANCIS, SM
   THORNTON, G
   BOWKER, M
AF LEIBSLE, FM
   MURRAY, PW
   FRANCIS, SM
   THORNTON, G
   BOWKER, M
TI ONE-DIMENSIONAL REACTIVITY IN CATALYSIS STUDIED WITH THE SCANNING TUNNELING MICROSCOPE
SO NATURE
LA English
DT Article
ID single-crystal; surface; co; adsorption; rh(110); no
AB THE scanning tunnelling microscope (STM) has yielded great insight into the structure of surfaces and into the dynamics of surface reconstruction and adsorption1. We show here that it can also provide direct information about the microscopic mechanisms of catalytic reactions on surfaces. We have studied the oxidation of carbon monoxide on an oxygen-precovered rhodium (110) surface, a process related to the catalytic removal of CO in exhaust gases2,3. The STM images show that the reactivity is strongly influenced by the oxygen-induced reconstructions of the surface. The reaction is initiated at high-energy adsorption sites, mainly at steps and domain boundaries of the adsorbed oxygen layer. The CO strips away one-dimensional islands of oxygen atoms on the reconstructed surface, proceeding in the [011] direction. More generally, these results show how the STM can provide insights into the microkinetics of surface reactions.
C1 UNIV LIVERPOOL,DEPT CHEM,LEVERHULME CTR INNOVAT CATALYSIS,LIVERPOOL L69 3BX,ENGLAND.
   UNIV MANCHESTER,DEPT CHEM,MANCHESTER M13 9PL,LANCS,ENGLAND.
C3 University of Liverpool; University of Manchester
RP LEIBSLE, FM (corresponding author), UNIV LIVERPOOL,INTERDISCIPLINARY RES CTR SURFACE SCI,POB 147,LIVERPOOL L69 3BX,ENGLAND.
NR 20
TC 99
Z9 102
U1 0
U2 31
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 706
EP 709
DI 10.1038/363706a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900051
DA 2026-03-10
ER

PT J
AU NEDIVI, E
   HEVRONI, D
   NAOT, D
   ISRAELI, D
   CITRI, Y
AF NEDIVI, E
   HEVRONI, D
   NAOT, D
   ISRAELI, D
   CITRI, Y
TI NUMEROUS CANDIDATE PLASTICITY-RELATED GENES REVEALED BY DIFFERENTIAL CDNA CLONING
SO NATURE
LA English
DT Article
ID molecular-cloning; stress proteins; expression; cells; acid; proenkephalin; mechanisms; extraction; sequence; seizure
AB PLASTICITY is a property of the nervous system that allows it to modify its response to an altered input. This capacity for change suggests that there are molecular mechanisms in neurons that can couple stimuli to long-term alterations in phenotype1-3. Neuronal excitation elicits rapid transcriptional activation of several immediate-early genes4, for example c-fos, c-jun and zif268. Many immediate-early genes encode transcription factors that control expression of downstream genes whose products are believed to bring about long-term plastic changes3,4. Here we use a highly sensitive differential complementary DNA cloning procedure to identify genes that may participate in long-term plasticity. We cloned 52 cDNAs of genes induced by the glutamate analogue kainate in the hippocampus dentate gyrus. The number of these candidate plasticity-related genes (CPGs) is estimated to be 500-1,000. One of the cloned CPGs (16C8), encoding a protease inhibitor, is induced by a stimulus producing long-term potentiation and during dentate gyrus development; a second, cpg1, is dependent on activation of the NMDA (N-methyl-D-aspartate) receptor for induction and encodes a new small, dentate-gyrus-specific protein. Seventeen of the cloned CPGs encode known proteins, including six suggesting that strong neuronal activation leads to de novo synthesis of vesicular and other synaptic components.
RP NEDIVI, E (corresponding author), WEIZMANN INST SCI,DEPT HORMONE RES,IL-76100 REHOVOT,ISRAEL.
NR 38
TC 445
Z9 498
U1 0
U2 15
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 24
PY 1993
VL 363
IS 6431
BP 718
EP 722
DI 10.1038/363718a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LJ339
UT WOS:A1993LJ33900055
PM 8515813
DA 2026-03-10
ER

PT J
AU NATAF, HC
   VANDECAR, J
AF NATAF, HC
   VANDECAR, J
TI SEISMOLOGICAL DETECTION OF A MANTLE PLUME
SO NATURE
LA English
DT Article
ID convection plumes; deep
AB A detailed seismological study of the mantle beneath the Bowie hotspot, west of Canada, reveals a zone of low seismic velocities. The anomaly, probed at a depth of approximately 700 km, adds a delay of 0.15 s to the travel times of seismic waves traversing a region approximately 150 km In diameter, located approximately 150 km away from the vertical projection of the Bowie seamount. This observation suggests that a mantle plume is present in the lower mantle beneath Bowie, with the amplitude of the anomaly implying a temperature contrast of about approximately 300 K.
C1 ECOLE NORMALE SUPER,DEPT TERRE ATMOSPHERE OCEAN,F-75231 PARIS 05,FRANCE.
   UNIV WASHINGTON,GEOPHYS PROGRAM,SEATTLE,WA 98195.
C3 Universite PSL; Ecole Normale Superieure (ENS); University of Washington; University of Washington Seattle
RP NATAF, HC (corresponding author), UNIV UTRECHT,DEPT THEORET GEOPHYS,POB 80021,3508 TA UTRECHT,NETHERLANDS.
NR 32
TC 82
Z9 86
U1 0
U2 9
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 115
EP 120
DI 10.1038/364115a0
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700039
DA 2026-03-10
ER

PT J
AU WOOD, SA
   ALLEN, ND
   ROSSANT, J
   AUERBACH, A
   NAGY, A
AF WOOD, SA
   ALLEN, ND
   ROSSANT, J
   AUERBACH, A
   NAGY, A
TI NON-INJECTION METHODS FOR THE PRODUCTION OF EMBRYONIC STEM CELL-EMBRYO CHIMERAS
SO NATURE
LA English
DT Article
ID mouse embryo
C1 MT SINAI HOSP, SAMUEL LUNENFELD RES INST, TORONTO M5G 1X5, ONTARIO, CANADA.
   AFRC, BABRAHAM INST, CAMBRIDGE CB2 4AT, ENGLAND.
C3 University of Toronto; Sinai Health System Toronto; Lunenfeld Tanenbaum Research Institute; UK Research & Innovation (UKRI); Biotechnology and Biological Sciences Research Council (BBSRC); Babraham Institute
RP WOOD, SA (corresponding author), MAX PLANCK INST IMMUNBIOL, DEPT MOLEC EMBRYOL, W-7800 FREIBURG, GERMANY.
NR 16
TC 200
Z9 235
U1 0
U2 2
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD SEP 2
PY 1993
VL 365
IS 6441
BP 87
EP 89
DI 10.1038/365087a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LV646
UT WOS:A1993LV64600062
PM 8361547
DA 2026-03-10
ER

PT J
AU HAGEN, MHJ
   MEIJER, EJ
   MOOIJ, GCAM
   FRENKEL, D
   LEKKERKERKER, HNW
AF HAGEN, MHJ
   MEIJER, EJ
   MOOIJ, GCAM
   FRENKEL, D
   LEKKERKERKER, HNW
TI DOES C-60 HAVE A LIQUID-PHASE
SO NATURE
LA English
DT Article
ID monte-carlo simulation; ensemble
AB ABOVE a substance's liquid-vapour critical point (T(c)), the distinction between the liquid and vapour phases disappears. Below the triple point (T(t)), meanwhile (at which solid, liquid and vapour coexist), only the solid and vapour are stable. The liquid range, T(c)/T(t), depends on the nature of the intermolecular forces: for argon, T(c)/T(t) = 1.8, whereas for sodium the ratio is 7.5. But might there be molecular substances that have no liquid phase at all? Here we present results which suggest that C60 is such a substance. We map out the phase diagram using computer simulations in which the C60 molecules are represented by spheres interacting via Lennard-Jones potentials summed over all 60 carbon atoms. We find that the sublimation line passes above the metastable liquid-vapour coexistence curve. By drawing an analogy with the aggregation of colloidal particles, we expect that solid C60 formed by nucleation from the vapour phase will be amorphous rather than crystalline.
C1 FOM,INST ATOM & MOLEC PHYS,KRUISLAAN 407,1098 SJ AMSTERDAM,NETHERLANDS.
   UNIV UTRECHT,VANT HOFF LAB,3584 CH UTRECHT,NETHERLANDS.
C3 AMOLF; Utrecht University
NR 12
TC 268
Z9 278
U1 1
U2 63
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD SEP 30
PY 1993
VL 365
IS 6445
BP 425
EP 426
DI 10.1038/365425a0
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LZ633
UT WOS:A1993LZ63300050
DA 2026-03-10
ER

PT J
AU SIROCKO, F
   SARNTHEIN, M
   ERLENKEUSER, H
   LANGE, H
   ARNOLD, M
   DUPLESSY, JC
AF SIROCKO, F
   SARNTHEIN, M
   ERLENKEUSER, H
   LANGE, H
   ARNOLD, M
   DUPLESSY, JC
TI CENTURY-SCALE EVENTS IN MONSOONAL CLIMATE OVER THE PAST 24,000 YEARS
SO NATURE
LA English
DT Article
ID indian-ocean; arabian sea; time scale; yr bp; level; circulation; calibration; holocene; record; bc
AB BOTH the marine sediment record and numerical modelling of the atmospheric summer circulation over the northern Indian Ocean and southeast Asia have shown that the monsoonal climate exhibits a direct but nonlinear response to the intensity of solar insolation during summer, with a time lag of several thousand years1,2. Here we present evidence from a high-resolution record of oxygen isotopes and carbonate spanning the past 24,000 calendar years that the response of the southwest monsoon over the Arabian Sea to long-term, gradual insolation changes occurred in several distinct events of less than 300 years duration, at 14,300, 13,500, 13,060, 9,900, 8,800 and 7,300 C-14 yr BP. Thus, during this transitional period from glacial to post-glacial conditions the slow solar forcing seems to have induced very rapid changes in local climate. We speculate that the rapid response may be related to albedo changes in Asia.
C1 COLUMBIA UNIV,LAMONT DOHERTY EARTH OBSERV,PALISADES,NY 10964.
   CEA,CNRS,CTR FAIBLES RADIOACT,F-91198 GIF SUR YVETTE,FRANCE.
   CHRISTIAN ALBRECHTS UNIV KIEL,INST KERNPHYS,W-2300 KIEL 1,GERMANY.
C3 Columbia University; CEA; Centre National de la Recherche Scientifique (CNRS); Universite Paris Saclay; University of Kiel
RP SIROCKO, F (corresponding author), CHRISTIAN ALBRECHTS UNIV KIEL,INST GEOL PALAONTOL,OLSHAUSENSTR 40-60,D-24098 KIEL,GERMANY.
NR 34
TC 563
Z9 610
U1 0
U2 84
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 322
EP 324
DI 10.1038/364322a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000052
DA 2026-03-10
ER

PT J
AU TAVLADORAKI, P
   BENVENUTO, E
   TRINCA, S
   DEMARTINIS, D
   CATTANEO, A
   GALEFFI, P
AF TAVLADORAKI, P
   BENVENUTO, E
   TRINCA, S
   DEMARTINIS, D
   CATTANEO, A
   GALEFFI, P
TI TRANSGENIC PLANTS EXPRESSING A FUNCTIONAL SINGLE-CHAIN FV-ANTIBODY ARE SPECIFICALLY PROTECTED FROM VIRUS ATTACK
SO NATURE
LA English
DT Article
ID bushy stunt virus; monoclonal-antibody; escherichia-coli; mosaic-virus; protein; infection; gene; resolution; domains; tobacco
AB EXPRESSION Of Viral genes in transgenic plants is a very effective tool for attenuating plant viral infection1-3. Nevertheless, the lack of generality and risk issues related to the expression of viral genes in plants4 might limit the exploitation of this strategy. Expression in plants of antibodies against essential viral proteins could provide an alternative approach to engineer viral resistance. Recently, expression of complete5-7 or engineered7-9 antibodies has been successfully achieved in plants. The engineered single-chain Fv antibody scFv (refs 10, 11) is particularly suitable for expression in plants because of its small size and the lack of assembly requirements. Here we present evidence that constitutive expression in transgenic plants of a scFv antibody, directed against the plant icosahedral tombusvirus artichoke mottled crinkle virus, causes reduction of infection incidence and delay in symptom development.
C1 ENEA, DIPARTIMENTO RIC & SVILUPPO AGROIND, DIV INGN GENET, CP 2400, I-00100 ROME, ITALY.
   SISSA, I-34013 TRIESTE, ITALY.
C3 Italian National Agency New Technical Energy & Sustainable Economics Development; Italian National Agency New Technical Energy & Sustainable Economics Development; International School for Advanced Studies (SISSA)
NR 30
TC 333
Z9 442
U1 0
U2 34
PU NATURE PUBLISHING GROUP
PI LONDON
PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND
SN 0028-0836
EI 1476-4687
J9 NATURE
JI Nature
PD DEC 2
PY 1993
VL 366
IS 6454
BP 469
EP 472
DI 10.1038/366469a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA MK098
UT WOS:A1993MK09800066
PM 8247156
DA 2026-03-10
ER

PT J
AU SCHAEFFER, P
   OCAMPO, R
   CALLOT, HJ
   ALBRECHT, P
AF SCHAEFFER, P
   OCAMPO, R
   CALLOT, HJ
   ALBRECHT, P
TI EXTRACTION OF BOUND PORPHYRINS FROM SULFUR-RICH SEDIMENTS AND THEIR USE FOR RECONSTRUCTION OF PALEOENVIRONMENTS
SO NATURE
LA English
DT Article
ID oil-shale; geochemical significance; chlorophyll-c; petroporphyrins; gilsonite; fossils
AB PORPHYRINS, which are present in most sediments and crude oils, represent the 'molecular fossils' of compounds such as chlorophylls, bacteriochlorophylls and haems in the organisms from which the organic material is derived1-4. They have the potential to provide information about palaeoenvironmental conditions at the time of deposition5-9. Porphyrins derived from degradation of chlorophylls are of particular interest because of the possibility of relating palaeoproductivity estimates from sediments to chlorophyll-based measurements of present-day productivity determined by remote sensing. But standard analytical methods do not detect all of the porphyrins present in a geological sample - a substantial fraction of the porphyrins may be bound to kerogen10,11 or to solvent-extractable macromolecules, or may be degraded by the oxidative extraction procedures. It has been shown recently12-16 that sulphur may play a crucial part in binding 'biomarker' molecules at an early stage of sediment diagenesis, and that desulphurization using Raney nickel may liberate small molecules bound to sulphur-containing species. Here we show that this approach releases large amounts of porphyrins from the total organic extract of a sulphur-rich marl. Liberating bound porphyrins in this way may greatly enhance the amount of information on palaeoenvironments that can be extracted from geochemical analysis of sediments.
C1 UNIV STRASBOURG 1,INST CHIM,CNRS,URA 31,1 RUE BLAISE PASCAL,F-67070 STRASBOURG,FRANCE.
C3 Universites de Strasbourg Etablissements Associes; Universite de Strasbourg; Centre National de la Recherche Scientifique (CNRS)
NR 32
TC 52
Z9 55
U1 0
U2 19
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 8
PY 1993
VL 364
IS 6433
BP 133
EP 136
DI 10.1038/364133a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LL367
UT WOS:A1993LL36700044
DA 2026-03-10
ER

PT J
AU CLOS, J
   RABINDRAN, S
   WISNIEWSKI, J
   WU, C
AF CLOS, J
   RABINDRAN, S
   WISNIEWSKI, J
   WU, C
TI INDUCTION TEMPERATURE OF HUMAN HEAT-SHOCK FACTOR IS REPROGRAMMED IN A DROSOPHILA CELL ENVIRONMENT
SO NATURE
LA English
DT Article
ID binding
AB HEAT shock factor (HSF)1,2, the transcriptional activator of eukaryotic heat shock genes, is induced to bind DNA by a monomer to trimer transition involving leucine zipper interactions3,4. Although this mode of regulation is shared among many eukaryotic species, there is variation in the temperature at which HSF binding activity is induced. We investigated the basis of this variation by analysing the response of a human HSF expressed in Drosophila cells and Drosophila HSF expressed in human cells. We report here that the temperature that induces DNA binding and trimerization of human HSF in Drosophila was decreased by approximately 10-degrees-C to the induction temperature for the host cell, whereas Drosophila HSF expressed in human cells was constitutively active. The results indicate that the activity of HSF in vivo is not a simple function of the absolute environmental temperature.
C1 NCI,BIOCHEM LAB,BLDG 37,RM 4C-09,BETHESDA,MD 20892.
C3 National Institutes of Health (NIH) - USA; NIH National Cancer Institute (NCI)
NR 16
TC 80
Z9 87
U1 0
U2 8
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 15
PY 1993
VL 364
IS 6434
BP 252
EP 255
DI 10.1038/364252a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LM683
UT WOS:A1993LM68300062
PM 8321322
DA 2026-03-10
ER

PT J
AU MCINTIRE, SL
   JORGENSEN, E
   KAPLAN, J
   HORVITZ, HR
AF MCINTIRE, SL
   JORGENSEN, E
   KAPLAN, J
   HORVITZ, HR
TI THE GABAERGIC NERVOUS-SYSTEM OF CAENORHABDITIS-ELEGANS
SO NATURE
LA English
DT Article
ID nematode ascaris; c-elegans; inhibitory motoneurons; gaba; neurons
AB Gamma-AMINOBUTYRIC acid (GABA) is the most abundant inhibitory neurotransmitter in vertebrates and invertebrates1. GABA receptors are the target of anxiolytic, antiepileptic and antispasmodic drugs2, as well as of commonly used insecticides3. How does a specific neurotransmitter such as GABA control animal behaviour? To answer this question, we identified all neurons that react with antisera raised against the neurotransmitter GABA in the nervous system of the nematode Caenorhabditis elegans. We determined the in vivo functions of 25 of the 26 GABAergic neurons by killing these cells with a laser microbeam in living animals and by characterizing a mutant defective in GABA expression. On the basis of the ultrastructurally defined connectivity of the C. elegans nervous system, we deduced how these GABAergic neurons act to control the body and enteric muscles necessary for different behaviours. Our findings provide evidence that GABA functions as an excitatory as well as an inhibitory neurotransmitter.
C1 MIT,DEPT BIOL,HOWARD HUGHES MED INST,CAMBRIDGE,MA 02139.
   HARVARD UNIV,SCH MED,PROGRAM NEUROSCI,BOSTON,MA 02115.
C3 Massachusetts Institute of Technology (MIT); Howard Hughes Medical Institute; Harvard University; Harvard Medical School
NR 25
TC 373
Z9 472
U1 0
U2 43
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 337
EP 341
DI 10.1038/364337a0
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000057
PM 8332191
DA 2026-03-10
ER

PT J
AU MCINTIRE, SL
   JORGENSEN, E
   HORVITZ, HR
AF MCINTIRE, SL
   JORGENSEN, E
   HORVITZ, HR
TI GENES REQUIRED FOR GABA FUNCTION IN CAENORHABDITIS-ELEGANS
SO NATURE
LA English
DT Article
ID nervous-system; c-elegans; acid; ascaris
AB Gamma-AMINOBUTYRIC acid (GABA) neurotransmission is widespread in vertebrate and invertebrate nervous systems1. Here we use a genetic approach to identify molecules specific to GABA function. On the basis of the known in vivo roles of GABAergic neurons in controlling behaviour of the nematode Caenorhabditis elegans2, we identified mutants defective in GABA-mediated behaviours. Five genes are necessary either for GABAergic neuronal differentiation or for pre- or postsynaptic GABAergic function. The gene unc-30 is required for the differentiation of a specific type of GABAergic neuron, the type-D inhibitory motor neuron. The gene unc-25 is necessary for GABA expression and probably encodes the GABA biosynthetic enzyme glutamic acid decarboxylase. The genes unc-46 and unc-47 seem to be required for normal GABA release. Finally, the gene unc-49 is apparently necessary postsynaptically for the inhibitory effect of GABA on the body muscles and might encode a protein needed for the function of a GABA(A)-like receptor. Some of these genes are likely to encode previously unidentified proteins required for GABA function.
C1 MIT,DEPT BIOL,HOWARD HUGHES MED INST,CAMBRIDGE,MA 02139.
   HARVARD UNIV,SCH MED,PROGRAM NEUROSCI,BOSTON,MA 02115.
C3 Howard Hughes Medical Institute; Massachusetts Institute of Technology (MIT); Harvard University; Harvard Medical School
NR 18
TC 261
Z9 337
U1 1
U2 31
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUL 22
PY 1993
VL 364
IS 6435
BP 334
EP 337
DI 10.1038/364334a0
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LN570
UT WOS:A1993LN57000056
PM 8332190
DA 2026-03-10
ER

PT J
AU ZIRIN, H
   WANG, H
AF ZIRIN, H
   WANG, H
TI NARROW LANES OF TRANSVERSE MAGNETIC-FIELD IN SUNSPOTS
SO NATURE
LA English
DT Article
ID flares
AB SOLAR flares are closely associated with magnetic activity on the surface of the Sun. They typically occur1 in complex sunspot groups, where the vertical magnetic fields reverse abruptly, and the horizontal (transverse) fields connecting the vertical poles are both sheared and strong. A single field inversion line may be the site of many flares1. Here we report observations of a large, active sunspot group which reveal a series of oppositely directed vertical-field inversions separated by extremely narrow elongated channels of intense horizontal fields. In a minimum-energy configuration, lines of force connecting oppositely directed vertical fields simply arch across the inversion line; but when newly emerged sunspots move through older magnetic-field configurations, the poles are pushed together and the field lines turn sharply along the inversion line to reconnect with the vertical field some distance away. These multiple channels of horizontal field imply a large curl term (del x B), and hence a substantial electric current. Our observations show that almost all of the larger flares in this region occur in these highly convoluted fields.
RP ZIRIN, H (corresponding author), CALTECH,BIG BEAR SOLAR OBSERV,PASADENA,CA 91125, USA.
NR 10
TC 67
Z9 70
U1 0
U2 1
PU MACMILLAN MAGAZINES LTD
PI LONDON
PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW
SN 0028-0836
EI 
J9 NATURE
JI Nature
PD JUN 3
PY 1993
VL 363
IS 6428
BP 426
EP 428
DI 10.1038/363426a0
PG 3
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA LE938
UT WOS:A1993LE93800050
DA 2026-03-10
ER

