Abstract:
:Guanosine tetraphosphate, recently discovered to mediate the regulatory relationship between protein synthesis and RNA accumulation in various bacteria, has been synthesized in vitro in large quantities and analyzed by natural-abundance (13)C nuclear magnetic resonance spectroscopy in order to confirm its structure and establish the positions of phosphate attachment. These studies have established its structure as guanosine 5'-diphosphate, 3'-diphosphate.
journal_name
Proc Natl Acad Sci U S Aauthors
Que L Jr,Willie GR,Cashel M,Bodley JW,Gray GRdoi
10.1073/pnas.70.9.2563subject
Has Abstractpub_date
1973-09-01 00:00:00pages
2563-6issue
9eissn
0027-8424issn
1091-6490journal_volume
70pub_type
杂志文章abstract::A physical map of the 9.2-Mbp Myxococcus xanthus DK1622 chromosome at a resolution of 25 kbp was constructed by using a strategy that is applicable to virtually all microorganisms. Segments of the chromosome were used as hybridization probes to subdivide a yeast artificial chromosome (YAC) library into groups of linke...
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.91.20.9584
更新日期:1994-09-27 00:00:00
abstract::Members of the arenavirus family, famous for their hemorrhagic syndromes, cause distinct neurological disorders; however, cellular and molecular targets as well as pathogenesis of peripheral nervous system disorders associated with these viruses are unknown. Using noncytolytic lymphocytic choriomeningitis virus, the p...
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.2232366100
更新日期:2003-12-23 00:00:00
abstract::Initiation of adenovirus DNA replication in vitro occurs on a linearized plasmid DNA containing 3,327 base pairs of the adenovirus terminal sequence. Various deletions have been constructed in the plasmid DNA and their template activities examined. Deletions from an internal restriction enzyme cleavage site that retai...
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.80.21.6446
更新日期:1983-11-01 00:00:00
abstract::RNA interference, mediated by small interfering RNAs (siRNAs), is a conserved regulatory process that has evolved as an antiviral defense mechanism in plants and animals. It is not known whether host cells also use siRNAs as an antibacterial defense mechanism in eukaryotes. Here, we report the discovery of an endogeno...
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.0608258103
更新日期:2006-11-21 00:00:00
abstract::The oscillator of the circadian clock of cyanobacteria is composed of three proteins, KaiA, KaiB, and KaiC, which together generate a self-sustained ∼24-h rhythm of phosphorylation of KaiC. The mechanism propelling this oscillator has remained elusive, however. We show that stacking interactions between the CI and CII...
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.1211508109
更新日期:2012-10-16 00:00:00
abstract::The versatility of CRISPR-Cas endonucleases as a tool for biomedical research has led to diverse applications in gene editing, programmable transcriptional control, and nucleic acid detection. Most CRISPR-Cas systems, however, suffer from off-target effects and unpredictable nonspecific binding that negatively impact ...
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.1918685117
更新日期:2020-05-26 00:00:00
abstract::Many urological studies rely on models of animals, such as rats and pigs, but their relation to the human urinary system is poorly understood. Here, we elucidate the hydrodynamics of urination across five orders of magnitude in body mass. Using high-speed videography and flow-rate measurement obtained at Zoo Atlanta, ...
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.1402289111
更新日期:2014-08-19 00:00:00
abstract::A fraction of the unintegrated viral DNA that appears early after infection of mouse cells by Moloney leukemia virus is infectious. The infectivity could be deomonstrated by an XC plaque assay of the cells exposed to DNA co-precipitated with calcium phosphate. The number of plaques deriving from closed-circular, super...
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.72.12.4910
更新日期:1975-12-01 00:00:00
abstract::A fundamental aspect of climate change is the potential shifts in flowering phenology and pollen initiation associated with milder winters and warmer seasonal air temperature. Earlier floral anthesis has been suggested, in turn, to have a role in human disease by increasing time of exposure to pollen that causes aller...
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.1014107108
更新日期:2011-03-08 00:00:00
abstract::Mesp2 is a transcription factor that plays fundamental roles in somitogenesis, and its expression is strictly restricted to the anterior presomitic mesoderm just before segment border formation. The transcriptional on-off cycle is linked to the segmentation clock. In our current study, we show that a T-box transcripti...
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.0508238103
更新日期:2006-03-07 00:00:00
abstract::C1q-like genes (C1ql1-C1ql4) encode small, secreted proteins that are expressed in differential patterns in the brain but whose receptors and functions remain unknown. BAI3 protein, in contrast, is a member of the cell-adhesion class of G protein-coupled receptors that are expressed at high levels in the brain but who...
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.1019577108
更新日期:2011-02-08 00:00:00
abstract::Metalloproteases (MPs) are a large and diverse class of enzymes implicated in numerous physiological and pathological processes, including tissue remodeling, peptide hormone processing, and cancer. MPs are tightly regulated by multiple posttranslational mechanisms in vivo, hindering their functional analysis by conven...
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.0402784101
更新日期:2004-07-06 00:00:00
abstract::Synucleinopathies are a group of progressive disorders characterized by the abnormal aggregation and accumulation of α-synuclein (aSyn), an abundant neuronal protein that can adopt different conformations and biological properties. Recently, aSyn pathology was shown to spread between neurons in a prion-like manner. Pr...
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.1606791113
更新日期:2016-10-18 00:00:00
abstract::Sands from various geographic locations reduce N(2) from the air to NH(3) and traces of N(2)H(4) on exposure to sunlight. This N(2) photofixation occurs under sterile conditions on the surface of finely dispersed titanium minerals such as rutile, utilizing reducing equivalents generated through the photolysis of chemi...
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.80.12.3873
更新日期:1983-06-01 00:00:00
abstract::We have investigated the role of Sonic hedgehog (Shh) in the development of facial structures by depriving chicken embryos of the most anterior sources of this morphogen, including the prechordal plate and the anterior ventral endoderm of the foregut, before the onset of neural crest cell (NCC) migration to the first ...
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.0604751103
更新日期:2006-08-01 00:00:00
abstract::Decision-makers increasingly seek scientific guidance on investing in nature, but biodiversity remains difficult to estimate across diverse landscapes. Here, we develop empirically based models for quantifying biodiversity across space. We focus on agricultural lands in the tropical forest biome, wherein lies the grea...
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.1604981113
更新日期:2016-12-20 00:00:00
abstract::Synthetic 3-phosphocitrate, an extremely potent inhibitor of calcium phosphate crystallization as determined in a nonbiological physical-chemical assay, has many similarities to a mitochondrial factor that inhibits crystallization of nondiffracting amorphous calcium phosphate. In order to determine whether phosphocitr...
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.78.9.5528
更新日期:1981-09-01 00:00:00
abstract::The infection of human cells by laboratory strains of human immunodeficiency virus type 1 (HIV-1) can be blocked readily in vitro by recombinant soluble CD4 and CD4-immunoglobulin hybrid molecules. In contrast, infection by primary isolates of HIV-1 is much less sensitive to blocking in vitro by soluble CD4-based mole...
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.88.16.7056
更新日期:1991-08-15 00:00:00
abstract::A critique is presented of the Lumsden-Wilson theory [Lumsden, C. J. & Wilson, E. O. (1980) Proc. Natl. Acad. Sci. USA 77, 4382-4386] of the transmission of cultural traits. An analysis of the underlying assumptions and the mathematical nature of the theory clarifies its essentially reductionist and determinist qualit...
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.78.6.3976
更新日期:1981-06-01 00:00:00
abstract::The discovery of RNAi has revolutionized loss-of-function genetic studies in mammalian systems. However, significant challenges still remain to fully exploit RNAi for mammalian genetics. For instance, genetic screens and in vivo studies could be broadly improved by methods that allow inducible and uniform gene express...
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.1019736108
更新日期:2011-03-01 00:00:00
abstract::Arabidopsis thaliana endosperm, a transient tissue that nourishes the embryo, exhibits extensive localized DNA demethylation on maternally inherited chromosomes. Demethylation mediates parent-of-origin-specific (imprinted) gene expression but is apparently unnecessary for the extensive accumulation of maternally biase...
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.1306164110
更新日期:2013-05-07 00:00:00
abstract::Rat thoracic aortic smooth muscle cells (line A10, ATCC CRL 1476) display a high density of atrial natriuretic factor (ANF) receptors. ANF stimulated the accumulation of cGMP in these cells in a time- and dose-dependent fashion. These cells are known to display a high density of vasopressin receptors of the vascular V...
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.83.22.8492
更新日期:1986-11-01 00:00:00
abstract::Extracts of Escherichia coli strains infected with bacteriophage phiX174 catalyze DNA synthesis dependent on double-stranded, circular phiX174 replicative form I (phiX RFI) by a semiconservative process. The reaction required Mg++, ATP, all four dNTP, and exogenous phiX RFI DNA as template and yielded phiX RFI and phi...
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.73.6.1887
更新日期:1976-06-01 00:00:00
abstract::We have isolated three classes of monoclonal antibodies against Drosophila cell-surface antigens that are expressed with positional specificity in imaginal discs. Comparison of immunofluorescence patterns with the wing-disc fate map reveals that expression of the antigens is not directly related to the specific type o...
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.81.23.7485
更新日期:1984-12-01 00:00:00
abstract::The subcellular localization of cathepsin B activity (EC 3.4.22.1) in three murine melanomas of increasing metastatic potential (Cloudman less than B16-F1 less than B16 amelanotic) was determined. Cathepsin B activity was localized in the heavy mitochondrial fraction of normal murine liver but in the light mitochondri...
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.83.8.2483
更新日期:1986-04-01 00:00:00
abstract::Fetal pancreatic beta cells demonstrate a deficient insulin release in response to glucose, but the underlying mechanism at the cellular level is unknown. By using beta cells from 21-day fetal rats we made an attempt to clarify the mechanism(s) behind this reduced glucose response. In addition to measuring insulin rel...
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.86.12.4505
更新日期:1989-06-01 00:00:00
abstract::Organic substances can adopt an amorphous solid or semisolid state, influencing the rate of heterogeneous reactions and multiphase processes in atmospheric aerosols. Here we demonstrate how molecular diffusion in the condensed phase affects the gas uptake and chemical transformation of semisolid organic particles. Flo...
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.1103045108
更新日期:2011-07-05 00:00:00
abstract::Surface functionalization of semiconductors has been the backbone of the newest developments in microelectronics, energy conversion, sensing device design, and many other fields of science and technology. Over a decade ago, the notion of viewing the surface itself as a chemical reagent in surface reactions was introdu...
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.1006656107
更新日期:2011-01-18 00:00:00
abstract::To examine the hypothesis that bone marrow consists of discrete stem cell regulatory volumes or domains, we studied spleen colony-forming unit (CFU-S) population growth kinetics in unirradiated WBB6F1-W/Wv mice receiving various doses of +/+ bone marrow cells. Assay of femoral marrow CFU-S content in the eight recipie...
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.79.3.840
更新日期:1982-02-01 00:00:00
abstract::A procedure for combined sequential affinity adsorption-electrophoresis has been devised. Its use for the rapid purification of a calcium-dependent cyclic nucleotide phosphodiesterase from bovine brain in high yield is described. In this procedure, proteins bound to a solid phase of calcium-dependent regulatory protei...
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.76.10.4903
更新日期:1979-10-01 00:00:00