Abstract：
:Cellular ras genes encode a family of membrane-associated proteins (p21ras) that bind guanine nucleotide and possess a low intrinsic GTPase activity. The p21ras proteins are ubiquitously expressed in mammalian cells and are thought to be involved in a growth-promoting signal transduction pathway; their mode of action, however, remains unknown. The ligand-induced movement of cell-surface receptors seems to be a primary event in the transduction of several extracellular signals that control cell growth and differentiation. In B lymphocytes, surface immunoglobulin receptors crosslinked by antibody or other multivalent ligands form aggregates called patches, which then collect into a single assembly, a cap, at one pole of the cell. This process constitutes the initial signal for the activation of a B cell. Here we show by immunofluorescence microscopy that p21ras co-caps with surface immunoglobulin molecules in mouse splenic B lymphocytes. In contrast, no apparent change in the distribution of p21ras occurs during the capping of concanavalin A receptors. The redistribution of p21ras is apparent at the early stages (patching) of immunoglobulin capping and is inhibited by metabolic inhibitors and the cytoskeleton-disrupting agents colchicine and cytochalasin D. The distribution of another membrane-associated guanine nucleotide-binding regulatory protein, the Gi alpha subunit, is not affected by surface immunoglobulin capping. These findings demonstrate that p21ras can migrate in a directed manner along the plasma membrane and suggest that p21ras may be a component of the signalling pathway initiated by the capping of surface immunoglobulin in B lymphocytes.
journal_name
Naturejournal_title
Natureauthors
Graziadei L,Riabowol K,Bar-Sagi Ddoi
10.1038/347396a0subject
Has Abstractpub_date
1990-09-27 00:00:00pages
396-400issue
6291eissn
0028-0836issn
1476-4687journal_volume
347pub_type
杂志文章相关文献
NATURE文献大全abstract：:The maintenance of genome stability during mitosis is coordinated by the spindle assembly checkpoint (SAC) through its effector the mitotic checkpoint complex (MCC), an inhibitor of the anaphase-promoting complex (APC/C, also known as the cyclosome)1,2. Unattached kinetochores control MCC assembly by catalysing a chan...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/s41586-018-0281-1
更新日期：2018-07-01 00:00:00
abstract：:The silicate Earth is strongly depleted in moderately volatile elements (such as lead, zinc, indium and alkali elements) relative to CI chondrites, the meteorites that compositionally most closely resemble the Sun. This depletion may be explained qualitatively by accretion of 10 to 20 per cent of a volatile-rich body ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature23645
更新日期：2017-09-27 00:00:00
abstract：:Eukaryotic cells make many types of primary and processed RNAs that are found either in specific subcellular compartments or throughout the cells. A complete catalogue of these RNAs is not yet available and their characteristic subcellular localizations are also poorly understood. Because RNA represents the direct out...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature11233
更新日期：2012-09-06 00:00:00
abstract：:Mitochondrial genomes (mitochondrial DNA, mtDNA) encode essential oxidative phosphorylation (OXPHOS) components. Because hundreds of mtDNAs exist per cell, a deletion in a single mtDNA has little impact. However, if the deletion genome is enriched, OXPHOS declines, resulting in cellular dysfunction. For example, Kearn...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature17989
更新日期：2016-05-19 00:00:00
abstract：:Several functionally important genetic elements (such as the TATA box, mRNA splice sequences, poly(A) addition signal) were first detected as short segments of unexplained sequence homology within non-coding regions of different genes. A short region of unknown sequence in the intron between the human J kappa and C ka...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/304447a0
更新日期：1983-08-04 00:00:00
abstract：:We often face alternatives that we are free to choose between. Planning movements to select an alternative involves several areas in frontal and parietal cortex that are anatomically connected into long-range circuits. These areas must coordinate their activity to select a common movement goal, but how neural circuits...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature06849
更新日期：2008-05-15 00:00:00
abstract：:A key step in the elimination of pathogens from the body is the covalent binding of complement proteins C3 and C4 to their surfaces. Proteolytic activation of these proteins results in a conformational change, and an internal thioester is exposed which reacts with amino or hydroxyl groups on the target surface to form...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/379177a0
更新日期：1996-01-11 00:00:00
abstract：:Growth factors raise intracellular pH (pHi) by stimulating Na+/H+ exchange in the absence of HCO3-. In mutant cells that lack the Na+/H+ exchange activity, this alkalinization does not occur, and the cells do not proliferate without artificial elevation of pHi. It has therefore been widely suggested that an early pHi ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/337648a0
更新日期：1989-02-16 00:00:00
abstract：:Chemokines are small secreted proteins that stimulate the directional migration of leukocytes and mediate inflammation. During screening of a murine choroid plexus complementary DNA library, we identified a new chemokine, designated neurotactin. Unlike other chemokines, neurotactin has a unique cysteine pattern, Cys-X...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/42491
更新日期：1997-06-05 00:00:00
abstract：:Human fibroblast cells produce beta-type interferon only in response to viral infection or treatment with an inducer such as poly(rI) X poly(rC); this event is most probably controlled at the transcriptional level (for review see ref. 1). To study the induction process, we inserted the human fibroblast interferon (IFN...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/301634a0
更新日期：1983-02-17 00:00:00
abstract：:Membrane-enclosed organelles, a defining characteristic of eukaryotic cells, are lost during differentiation of specific cell types such as reticulocytes (an intermediate in differentiation of erythrocytes), central fibre cells of the eye lens, and keratinocytes. The degradation of these organelles must be tightly reg...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/26500
更新日期：1998-09-24 00:00:00
abstract：:When a force deforms an elastic object, practical experience suggests that the resulting displacement will be in the same direction as the force. This property is known as positive stiffness. Less familiar is the concept of negative stiffness, where the deforming force and the resulting displacement are in opposite di...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/35069035
更新日期：2001-03-29 00:00:00
abstract：:Bone has recently emerged as a pleiotropic endocrine organ that secretes at least two hormones, FGF23 and osteocalcin, which regulate kidney function and glucose homeostasis, respectively. These findings have raised the question of whether other bone-derived hormones exist and what their potential functions are. Here ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature21697
更新日期：2017-03-16 00:00:00
abstract：:The three-dimensional structures of macromolecules and their complexes are mainly elucidated by X-ray protein crystallography. A major limitation of this method is access to high-quality crystals, which is necessary to ensure X-ray diffraction extends to sufficiently large scattering angles and hence yields informatio...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature16949
更新日期：2016-02-11 00:00:00
abstract：:One way of accounting for lowered atmospheric carbon dioxide concentrations during Pleistocene glacial periods is by invoking the Antarctic stratification hypothesis, which links the reduction in CO2 to greater stratification of ocean surface waters around Antarctica. As discussed by Sigman and Boyle, this hypothesis ...
journal_title：Nature
pub_type： 评论,杂志文章
doi：10.1038/35088129
更新日期：2001-08-09 00:00:00
abstract：:Mutations in the p53 tumour-suppressor gene are the most frequently observed genetic lesions in human cancers. To investigate the role of the p53 gene in mammalian development and tumorigenesis, a null mutation was introduced into the gene by homologous recombination in murine embryonic stem cells. Mice homozygous for...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/356215a0
更新日期：1992-03-19 00:00:00
abstract：:Modern chitons (Mollusca: Polyplacophora) possess a highly conserved skeleton of eight shell plates (valves) surrounded by spicules or scales, and fossil evidence suggests that the chiton skeleton has changed little since the first appearance of the class in the Late Cambrian period (about 500 million years before pre...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature02548
更新日期：2004-05-20 00:00:00
abstract：:In this Letter, errors in Supplementary Table 1 have been corrected. ...
journal_title：Nature
pub_type： 杂志文章,已发布勘误
doi：10.1038/s41586-018-0573-5
更新日期：2018-11-01 00:00:00
abstract：:The realization of superfluidity in a dilute gas of fermionic atoms, analogous to superconductivity in metals, represents a long-standing goal of ultracold gas research. In such a fermionic superfluid, it should be possible to adjust the interaction strength and tune the system continuously between two limits: a Barde...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature02199
更新日期：2003-12-04 00:00:00
abstract：:The rat hippocampus receives a strong cholinergic innervation from the medial septum; information about the development and function of this pathway could help to elucidate the mechanisms of memory functions. Previous electrophysiological studies have shown that septal stimulation in vivo facilitates commissural and p...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/313577a0
更新日期：1985-02-14 00:00:00
abstract：:Since the discovery of superconductivity in the high-transition-temperature (high-T(c)) copper oxides two decades ago, it has been firmly established that the CuO(2) plane is essential for superconductivity and gives rise to a host of other very unusual properties. A new family of superconductors with the general comp...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature07081
更新日期：2008-06-26 00:00:00
abstract：:Experimental and simulation studies show that small monomeric proteins fold in one kinetic step, which entails overcoming the free-energy barrier between the unfolded and the native protein through a transition state. Two models of transition state formation have been proposed: a 'nonspecific' one in which it depends ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/379096a0
更新日期：1996-01-04 00:00:00
abstract：:Neurons in the developing rodent cortex are generated from radial glial cells that function as neural stem cells. These epithelial cells line the cerebral ventricles and generate intermediate progenitor cells that migrate into the subventricular zone (SVZ) and proliferate to increase neuronal number. The developing hu...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature08845
更新日期：2010-03-25 00:00:00
abstract：:Sex-determination genes are among the most fluid features of the genome in many groups of animals. In some taxa the master sex-determining gene moves frequently between chromosomes, whereas in other taxa different genes have been recruited to determine the sex of the zygotes. There is a well developed theory for the o...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature06178
更新日期：2007-10-18 00:00:00
abstract：:Over the last twenty years classical views of how compound eyes work optically have undergone a series of overhauls. Exner's central concept of an optically inhomogeneous lens cylinder has survived, and such devices are now made commercially. He was wrong, however, about some crustacean eyes. They produce images by a ...
journal_title：Nature
pub_type： 杂志文章,评审
doi：10.1038/287681a0
更新日期：1980-10-23 00:00:00
abstract：:The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this dista...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature03614
更新日期：2005-05-19 00:00:00
abstract：:Evolutionary adaptation can be rapid and potentially help species counter stressful conditions or realize ecological opportunities arising from climate change. The challenges are to understand when evolution will occur and to identify potential evolutionary winners as well as losers, such as species lacking adaptive c...
journal_title：Nature
pub_type： 杂志文章,评审
doi：10.1038/nature09670
更新日期：2011-02-24 00:00:00
abstract：:Herpesviruses are characterized by their ability to maintain life-long latent infections in their animal hosts. However, the mechanisms that allow establishment and maintenance of the latent state remain poorly understood. Herpes simplex virus 1 (HSV-1) establishes latency in neurons of sensory ganglia, where the only...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature07103
更新日期：2008-08-07 00:00:00
abstract：:Techniques to facilitate controlled interactions between single photons and atoms are now being actively explored. These techniques are important for the practical realization of quantum networks, in which multiple memory nodes that utilize atoms for generation, storage and processing of quantum states are connected b...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/nature04327
更新日期：2005-12-08 00:00:00
abstract：:The gal operon of Escherichia coli is controlled by two independent promotors--one is activated and the other inhibited by cyclic AMP and cyclic AMP receptor protein. The two promotors are modulated, however, by the same operator locus and receptor protein. ...
journal_title：Nature
pub_type： 杂志文章
doi：10.1038/279492a0
更新日期：1979-06-07 00:00:00
