Abstract:
:The GTPase-activating protein (GAP) has been postulated to function either as a negative regulator or as a possible target protein of Ras in mammalian cells and Xenopus oocytes. Ras must be localized in the plasma membrane of vertebrate cells to function, but GAP is localized in the cytosol. To test whether Ras function depends on a cytosolic factor such as GAP, we microinjected into Xenopus oocytes a form of Saccharomyces cerevisiae RAS1 ([Leu68]RAS1 terminated at residue 185, called [Leu68]RAS1(term.] that lacks the consensus membrane localization site, does not respond to GAP in a GTPase assay, but binds to GAP 100-fold more tightly than [Val12]Ras. [Leu68]RAS1(term.) alone did not stimulate oocyte germinal-vesicle breakdown. Instead, [Leu68]RAS1(term.) was observed to inhibit the action of insulin-like growth factor 1 or microinjected [Val12]Ras but not the action of progesterone as monitored by germinal-vesicle breakdown. Coinjection of purified mammalian GAP with [Leu68]RAS1(term.) reduced the inhibition of [Val12]Ras-stimulated germinal-vesicle breakdown. The results raise the possibility that a cytosolic factor is required for the action of [Val12]Ras in Xenopus oocytes and that this factor is either GAP or another protein with which GAP can compete for binding to [Leu68]RAS1(term.).
journal_name
Proc Natl Acad Sci U S Aauthors
Gibbs JB,Schaber MD,Schofield TL,Scolnick EM,Sigal ISdoi
10.1073/pnas.86.17.6630subject
Has Abstractpub_date
1989-09-01 00:00:00pages
6630-4issue
17eissn
0027-8424issn
1091-6490journal_volume
86pub_type
杂志文章abstract::The liver provides for long-term energy needs of the body by converting excess carbohydrate into fat for storage. Insulin is one factor that promotes hepatic lipogenesis, but there is increasing evidence that glucose also contributes to the coordinated regulation of carbohydrate and fat metabolism in liver by mechanis...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0401516101
更新日期:2004-05-11 00:00:00
abstract::The vulval development of Caenorhabditis elegans provides an opportunity to investigate genetic networks that control gene expression during organogenesis. During the fourth larval stage (L4), seven vulval cell types are produced, each of which executes a distinct gene expression program. We analyze how the expression...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0408122102
更新日期:2005-04-05 00:00:00
abstract::Coagulation factor V is a high molecular weight plasma glycoprotein that participates as a cofactor in the conversion of prothrombin to thrombin by factor Xa. A phage lambda gt11 Hep G2 cell cDNA expression library was screened by using an affinity-purified antibody to human factor V, and 11 positive clones were isola...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.83.18.6800
更新日期:1986-09-01 00:00:00
abstract::A fragment of the cloned gene for the human myeloma ND epsilon chain, coding for the second, third, and fourth domains of the immunoglobulin, has been coupled to the tryptophan control region of an expression plasmid and subcloned in Escherichia coli. Induction of gene expression results in the synthesis of the expect...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.10.2955
更新日期:1984-05-01 00:00:00
abstract::Although it has long been recognized that the enteric community of bacteria that inhabit the human distal intestinal track broadly impacts human health, the biochemical details that underlie these effects remain largely undefined. Here, we report a broad MS-based metabolomics study that demonstrates a surprisingly lar...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0812874106
更新日期:2009-03-10 00:00:00
abstract::Landscape-scale reconstructions of ancient environments within the cradle of humanity may reveal insights into the relationship between early hominins and the changing resources around them. Many studies of Olduvai Gorge during Pliocene-Pleistocene times have revealed the presence of precession-driven wet-dry cycles a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2004532117
更新日期:2020-10-06 00:00:00
abstract::A primary method for studying cellular function is to examine cell morphology after a given manipulation. Fluorescent markers attached to proteins/intracellular structures of interest in conjunction with 3D fluorescent microscopy are frequently exploited for functional analysis. Despite the central role of morphology ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1117796109
更新日期:2012-05-29 00:00:00
abstract::Recently, hepatic peroxisome proliferator-activated receptor (PPAR)γ has been implicated in hepatic lipid accumulation. We found that the C3H mouse strain does not express PPARγ in the liver and, when subject to a high-fat diet, is resistant to hepatic steatosis, compared with C57BL/6 (B6) mice. Adenoviral PPARγ2 inje...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1203218109
更新日期:2012-08-21 00:00:00
abstract::Protein kinases are important mediators of much of the signal transduction that occurs in eukaryotic cells. Unfortunately, the identification of protein kinase substrates has proven to be a difficult task, and we generally know few, if any, of the physiologically relevant targets of any particular kinase. Here, we des...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0501046102
更新日期:2005-09-27 00:00:00
abstract::Solid-state cross-polarization/magic-angle sample-spinning (13)C NMR spectra have been recorded on chlorophyll a-water aggregates, methyl pyrochlorophyllide a, and methyl pyropheophorbide a (derivatives that lack a phytyl chain). Spectra have also been collected under a decoupling regime in which resonances of certain...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.2.641
更新日期:1984-01-01 00:00:00
abstract::We are presented with choices each day about how to invest our effort to achieve our goals. Critically, these decisions must frequently be made under conditions of incomplete information, where either the effort required or possible reward to be gained is uncertain. Such choices therefore require the development of po...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1800444115
更新日期:2018-05-29 00:00:00
abstract::The goal of this study was to characterize and classify pulmonary neuroendocrine tumors based on array comparative genomic hybridization (aCGH). Using aCGH, we performed karyotype analysis of 33 small cell lung cancer (SCLC) tumors, 13 SCLC cell lines, 19 bronchial carcinoids, and 9 gastrointestinal carcinoids. In con...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1008132107
更新日期:2010-07-20 00:00:00
abstract::AB-type toxins, like other bacterial toxins, are notably opportunistic molecules. They rely on target cell receptors to reach the appropriate location within the target cell where translocation of their enzymatic subunits occurs. The anthrax toxin, however, times its own uptake, suggesting that toxin binding triggers ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0910782107
更新日期:2010-01-26 00:00:00
abstract::Like all aliphatic amines, the polyamines spermine and spermidine are physical quenchers of singlet molecular oxygen (1O2*). The rate constants of these processes were determined in vitro with photochemically generated 1O2* and the hydrocarbon rubrene as substrate, in pyridine. At millimolar concentration, spermine an...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.23.11426
更新日期:1992-12-01 00:00:00
abstract::Ubc13 is a ubiquitin-conjugating enzyme responsible for noncanonical ubiquitination of TNF receptor-associated factor (TRAF)-family adapter proteins involved in Toll-like receptor and TNF-family cytokine receptor signaling, which are regulators of innate immunity. Gene ablation was used to study the function of Ubc13 ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0700548104
更新日期:2007-04-10 00:00:00
abstract::Molecular dynamics (MD) simulations provide essential information about the thermodynamics and dynamics of proteins. To construct the free-energy surface from equilibrium trajectories, it is necessary to group the individual snapshots in a meaningful way. The inherent structures (IS) are shown to provide an appropriat...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0915087107
更新日期:2010-05-18 00:00:00
abstract::The Kitaev model with an applied magnetic field in the [Formula: see text] direction shows two transitions: from a nonabelian gapped quantum spin liquid (QSL) to a gapless QSL at [Formula: see text] and a second transition at a higher field [Formula: see text] to a gapped partially polarized phase, where K is the stre...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1821406116
更新日期:2019-06-18 00:00:00
abstract::The paradigm of bacterial quorum sensing (QS), which mediates cell-density-dependent gene expression, usually has been studied in high-cell-density planktonic liquid cultures or in biofilms in which signal concentrations accumulate to sufficiently high levels to induce QS. Presumably under conditions with restricted d...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0711723105
更新日期:2008-02-26 00:00:00
abstract::The notion of stability of a local ring arises naturally in investigating completed moduli spaces via geometric invariant theory. A scheme corresponding to a boundary point of a moduli space of nonsingular varieties cannot have unstable singular points. This paper reports some results concerning the stability of surfa...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.75.9.4085
更新日期:1978-09-01 00:00:00
abstract::Circular RNA replicons have been reported in plants and, in one case, in animal cells. We describe such an element in yeast. In certain yeast strains, a 20S RNA species appears on transfer of cells to acetate medium. This phenotype shows cytoplasmic (non-Mendelian) inheritance and the 20S RNA is associated with 23-kDa...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.87.19.7628
更新日期:1990-10-01 00:00:00
abstract::Electron transfer dissociation (ETD) is a recently introduced mass spectrometric technique that provides a more comprehensive coverage of peptide sequences and posttranslational modifications. Here, we evaluated the use of ETD for a global phosphoproteome analysis. In all, we identified a total of 1,435 phosphorylatio...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0611217104
更新日期:2007-02-13 00:00:00
abstract::A technique is described for isolation of plasmid DNA in closed and open circular double-stranded forms from bacterial cells, by use of ATP-dependent deoxyribonuclease purified from Micrococcus luteus. This DNase, acting only upon linear DNA molecules, degrades all bacterial chromosomal DNA extracted in the linear for...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.70.10.2884
更新日期:1973-10-01 00:00:00
abstract::Transient cytosolic Ca(2+) ([Ca(2+)](cyt)) elevations are early events in plant signaling pathways including those related to abiotic stress. The restoration of [Ca(2+)](cyt) to prestimulus levels involves ATP-driven Ca(2+) pumps, but direct evidence for an essential role of a plant Ca(2+)-ATPase in abiotic stress ada...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0800864105
更新日期:2008-12-09 00:00:00
abstract::These experiments investigate the capacity of thalamic and cortical structures in a sensory system to process information of a modality normally associated with another system. Retinal ganglion cells in newborn Syrian hamsters were made to project permanently to the main thalamic somatosensory (ventrobasal) nucleus. W...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.1.357
更新日期:1989-01-01 00:00:00
abstract::Acyl-homoserine lactone (acyl-HSL) signaling is thought to mediate quorum sensing in many species of Proteobacteria. The opportunistic human pathogen Pseudomonas aeruginosa uses acyl-HSLs to regulate hundreds of genes, including many that code for extracellular virulence factors. The idea that the P. aeruginosa acyl-H...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0503728102
更新日期:2005-06-21 00:00:00
abstract::We previously reported that long-term cyclic estrogen (E) treatment reverses age-related impairment of cognitive function mediated by the dorsolateral prefrontal cortex (dlPFC) in ovariectomized (OVX) female rhesus monkeys, and that E induces a corresponding increase in spine density in layer III dlPFC pyramidal neuro...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0704757104
更新日期:2007-07-03 00:00:00
abstract::This paper is devoted to the study of the arithmetic properties of values of G-functions introduced by Siegel [Siegel, C. L. (1929) Abh. Preuss. Akad. Wiss. Phys.-Math. Kl. 1]. One of the main results is a theorem on the linear independence of values of G-functions at rational points close to the origin. In this theor...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.22.7261
更新日期:1984-11-01 00:00:00
abstract::A sequence-specific single-stranded DNA-binding protein from the trypanosomatid protozoan Crithidia fasciculata binds to a sequence of 12 nucleotides located at the origin of replication of kinetoplast DNA minicircles. This sequence, termed the universal minicircle sequence (UMS), is conserved in the kinetoplast DNA m...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.15.6891
更新日期:1992-08-01 00:00:00
abstract::Symbiotic microbes impact the severity of a variety of diseases through regulation of T-cell development. However, little is known regarding the molecular mechanisms by which this is accomplished. Here we report that a secreted factor, Erdr1, is regulated by the microbiota to control T-cell apoptosis. Erdr1 expression...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1619336114
更新日期:2017-05-23 00:00:00
abstract::Eukaryotic initiator proteins form origin recognition complexes (ORCs) that bind to replication origins during most of the cell cycle and direct assembly of prereplication complexes (pre-RCs) before the onset of S phase. In the eubacterium Escherichia coli, there is a temporally similar nucleoprotein complex comprisin...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0909472106
更新日期:2009-11-03 00:00:00