Life in the end-Permian dead zone.

abstract：:The basidiomycete Ustilago maydis is the causative agent of the disease corn smut. To be pathogenic, strains of U. maydis must be heterozygous for a locus called "b," which appears to control both pathogenicity and sexual development. Two alleles of the b locus of U. maydis were isolated by complementation and hybridi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Kronstad JW,Leong SA

更新日期：1989-02-01 00:00:00

abstract：:Escherichia coli fMet-tRNAfMet alters the pattern of promoter selection of E. coli RNA polymerase (RNA nucleotidyltransferase, nucleosidetriphosphate:RNA nucleotidyltransferase; EC 2.7.7.6), affecting RNA synthesis from the rRNA, suIII+tRNA, and lac promoters in different ways. The in vitro synthesis of the stable RNA...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Debenham PG,Pongs O,Travers AA

更新日期：1980-02-01 00:00:00

abstract：:Lost myelin can be replaced after injury or during demyelinating diseases in a regenerative process called remyelination. In the central nervous system (CNS), the myelin sheaths, which protect axons and allow the fast propagation of electrical impulses, are produced by oligodendrocytes. The abundance and widespread di...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Bielecki B,Mattern C,Ghoumari AM,Javaid S,Smietanka K,Abi Ghanem C,Mhaouty-Kodja S,Ghandour MS,Baulieu EE,Franklin RJ,Schumacher M,Traiffort E

更新日期：2016-12-20 00:00:00

abstract：:Electron spectroscopic imaging, a new technique that permits the quantitative detection of the spatial distributions of atomic elements at high resolution, has been applied to the epiphyseal zone of hypertrophy in the mouse for the visualization of calcium, phosphorus, and sulfur. Longitudinally sectioned epiphyseal g...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Arsenault AL,Ottensmeyer FP

更新日期：1983-03-01 00:00:00

abstract：:Seemingly similar individuals often experience drastically different success trajectories, with some repeatedly failing and others consistently succeeding. One explanation is preexisting variability along unobserved fitness dimensions that is revealed gradually through differential achievement. Alternatively, positive...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： van de Rijt A,Kang SM,Restivo M,Patil A

更新日期：2014-05-13 00:00:00

abstract：:With global heavy metal contamination increasing, plants that can process heavy metals might provide efficient and ecologically sound approaches to sequestration and removal. Mercuric ion reductase, MerA, converts toxic Hg2+ to the less toxic, relatively inert metallic mercury (Hg0) The bacterial merA sequence is rich...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Rugh CL,Wilde HD,Stack NM,Thompson DM,Summers AO,Meagher RB

更新日期：1996-04-16 00:00:00

abstract：:Telomerase is an RNA-directed DNA polymerase, composed of RNA and protein subunits, that replicates the telomere ends of linear eukaryotic chromosomes. Using a genetic strategy described here, we identify the product of the EST2 gene, Est2p, as a subunit of telomerase in the yeast Saccharomyces cerevisiae. Est2p is re...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Counter CM,Meyerson M,Eaton EN,Weinberg RA

更新日期：1997-08-19 00:00:00

abstract：:Syncytins are envelope genes of retroviral origin that have been co-opted for a role in placentation and likely contribute to the remarkable diversity of placental structures. Independent capture events have been identified in primates, rodents, lagomorphs, and carnivores, where they are involved in the formation of a...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Cornelis G,Heidmann O,Degrelle SA,Vernochet C,Lavialle C,Letzelter C,Bernard-Stoecklin S,Hassanin A,Mulot B,Guillomot M,Hue I,Heidmann T,Dupressoir A

更新日期：2013-02-26 00:00:00

abstract：:Adult rat arterial smooth muscle cells (SMC) in primary culture modulate from contractile to synthetic phenotype. This process includes partial loss of myofilaments and formation of an extensive rough endoplasmic reticulum and a large Golgi complex. It gives the cells the ability to initiate DNA synthesis and actively...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Nilsson J,Sjölund M,Palmberg L,Thyberg J,Heldin CH

更新日期：1985-07-01 00:00:00

abstract：:The intestinal mucosa exists in dynamic balance with trillions of luminal microbes. Disruption of the intestinal epithelial barrier, commonly observed in mucosal inflammation and diseases such as inflammatory bowel diseases (IBDs), is often associated with dysbiosis, particularly decreases in species producing short-c...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Wang RX,Lee JS,Campbell EL,Colgan SP

更新日期：2020-05-26 00:00:00

abstract：:Respiratory cytochrome c has been found to be phosphorylated at tyrosine 97 in the postischemic brain upon neuroprotective insulin treatment, but how such posttranslational modification affects mitochondrial metabolism is unclear. Here, we report the structural features and functional behavior of a phosphomimetic cyto...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Guerra-Castellano A,Díaz-Quintana A,Pérez-Mejías G,Elena-Real CA,González-Arzola K,García-Mauriño SM,De la Rosa MA,Díaz-Moreno I

更新日期：2018-07-31 00:00:00

abstract：:Enveloped viruses exploit the endomembrane system to enter host cells. Through a cascade of membrane-trafficking events, virus-bearing vesicles fuse with acidic endosomes and/or lysosomes mediated by SNAREs triggering viral fusion. However, the molecular mechanisms underlying this process remain elusive. Here, we foun...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Pirooz SD,He S,Zhang T,Zhang X,Zhao Z,Oh S,O'Connell D,Khalilzadeh P,Amini-Bavil-Olyaee S,Farzan M,Liang C

更新日期：2014-02-18 00:00:00

abstract：:The immunoglobulin light chain is thought to be organized into two structural domains, the constant and the variable regions, linked by a switch region of lesser tertiary organization. Light chains of homogeneous rabbit antibodies to pneumococcal polysaccharides labeled with (125)I were subjected to trypsin digestion ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Poulsen K,Fraser KJ,Haber E

更新日期：1972-09-01 00:00:00

abstract：:The all-cis hexose D-allose, fed to hamster fibroblast cultures over 14-20 hr, brings about a striking down-regulation of hexose transport. This down-regulation by allose is inhibited by 2,4-dinitrophenol. By using D-[14C]allose and thin-layer chromatography, two types of products accumulated that have been identified...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ullrey DB,Kalckar HM

更新日期：1991-02-15 00:00:00

abstract：:The carbon budget and dynamics of the Earth's interior, including the core, are currently very poorly understood. Diamond-bearing, mantle-derived rocks show a very well defined peak at δ(13)C ≈ -5 ± 3‰ with a very broad distribution to lower values (∼-40‰). The processes that have produced the wide δ(13)C distribution...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Horita J,Polyakov VB

更新日期：2015-01-06 00:00:00

abstract：:The spatial distribution of plant defenses within a leaf may be critical in explaining patterns of herbivory. The generalist lepidopteran larvae, Helicoverpa armigera (the cotton bollworm), avoided the midvein and periphery of Arabidopsis thaliana rosette leaves and fed almost exclusively on the inner lamina. This fee...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Shroff R,Vergara F,Muck A,Svatos A,Gershenzon J

更新日期：2008-04-22 00:00:00

abstract：:In the absence of any overt task performance, it has been shown that spontaneous, intrinsic brain activity is expressed as systemwide, resting-state networks in the adult brain. However, the route to adult patterns of resting-state activity through neuronal development in the human brain is currently unknown. Therefor...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Fransson P,Skiöld B,Horsch S,Nordell A,Blennow M,Lagercrantz H,Aden U

更新日期：2007-09-25 00:00:00

abstract：:The repair of DNA double-strand breaks (DSBs) requires open, flexible chromatin domains. The NuA4-Tip60 complex creates these flexible chromatin structures by exchanging histone H2A.Z onto nucleosomes and promoting acetylation of histone H4. Here, we demonstrate that the accumulation of H2A.Z on nucleosomes at DSBs is...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Gursoy-Yuzugullu O,Ayrapetov MK,Price BD

更新日期：2015-06-16 00:00:00

abstract：:Cardiotoxin VII4 from Naja mossambica mossambica crystallizes in space group P61 (a = b = 73.9 A; c = 59.0 A) with two molecules of toxin (molecular mass = 6715 Da) in the asymmetric unit. The structure was solved by using a combination of multiple isomorphous replacement and density modification methods. Model buildi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Rees B,Samama JP,Thierry JC,Gilibert M,Fischer J,Schweitz H,Lazdunski M,Moras D

更新日期：1987-05-01 00:00:00

abstract：:Mammalian class A macrophage-specific scavenger receptors (SR-A) exhibit unusually broad binding specificity for a wide variety of polyanionic ligands. The properties of these receptors suggest that they may be involved in atherosclerosis and host defense. We have previously observed a similar receptor activity in Dro...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Pearson A,Lux A,Krieger M

更新日期：1995-04-25 00:00:00

abstract：:The mitochondrial trifunctional protein (TFP) catalyzes three reactions in the fatty acid β-oxidation process. Mutations in the two TFP subunits cause mitochondrial trifunctional protein deficiency and acute fatty liver of pregnancy that can lead to death. Here we report a 4.2-Å cryo-electron microscopy α2β2 tetrameri...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Liang K,Li N,Wang X,Dai J,Liu P,Wang C,Chen XW,Gao N,Xiao J

更新日期：2018-07-03 00:00:00

abstract：:The DNA-binding domain of c-Myb consists of three homologous tandem repeats of 52 amino acids. The structure of the third (C-terminal) repeat obtained by NMR analysis has a conformation related to the helix-turn-helix motif. To identify the role of each repeat in the sequence recognition of DNA, we analyzed specific i...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Tanikawa J,Yasukawa T,Enari M,Ogata K,Nishimura Y,Ishii S,Sarai A

更新日期：1993-10-15 00:00:00

abstract：:A technique for systematic peptide variation by a combination of rational and evolutionary approaches is presented. The design scheme consists of five consecutive steps: (i) identification of a "seed peptide" with a desired activity, (ii) generation of variants selected from a physicochemical space around the seed pep...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Schneider G,Schrödl W,Wallukat G,Müller J,Nissen E,Rönspeck W,Wrede P,Kunze R

更新日期：1998-10-13 00:00:00

abstract：:Somatic-cell hybrids have been shown to maintain the correct epigenetic chromatin states to study developmental globin gene expression as well as gene expression on the active and inactive X chromosomes. This suggests the potential use of somatic-cell hybrids containing either a maternal or a paternal human chromosome...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Gabriel JM,Higgins MJ,Gebuhr TC,Shows TB,Saitoh S,Nicholls RD

更新日期：1998-12-08 00:00:00

abstract：:The development of antimicrobials is critical in this time of increasing antibiotic resistance of most clinically relevant bacteria. To date, all current antibiotics focus on inhibiting crucial enzymatic activities of their protein targets (i.e., trimethoprim for dihydrofolate reductase), thus disrupting in vitro esse...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Shakhnovich EA,Hung DT,Pierson E,Lee K,Mekalanos JJ

更新日期：2007-02-13 00:00:00

abstract：:Analysis of the mRNA capping apparatus of the malaria parasite Plasmodium falciparum illuminates an evolutionary connection to fungi rather than metazoans. We show that P. falciparum encodes separate RNA guanylyltransferase (Pgt1) and RNA triphosphatase (Prt1) enzymes and that the triphosphatase component is a member ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ho CK,Shuman S

更新日期：2001-03-13 00:00:00

abstract：:The integrity of the endothelial barrier between circulating blood and tissue is important for blood vessel function and, ultimately, for organ homeostasis. Here, we developed a vessel-on-a-chip with perfused endothelialized channels lined with human bone marrow stromal cells, which adopt a mural cell-like phenotype t...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Alimperti S,Mirabella T,Bajaj V,Polacheck W,Pirone DM,Duffield J,Eyckmans J,Assoian RK,Chen CS

更新日期：2017-08-15 00:00:00

abstract：:For study of the basis of an X-linked form of gout in man, several clonal lines deficient in hypoxanthine-guanine phosphoribosyltransferase (EC 2.4.2.8) were selected from the human lymphoblast line WI-L2 by spontaneous and mutagen-induced resistance to 10 muM 8-azaguanine. Three groups could be defined: (1) clones wi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Lever JE,Nuki G,Seegmiller JE

更新日期：1974-07-01 00:00:00

abstract：:The human chemokine receptors CCR5 and CXCR4 have emerged as the predominant cofactors, along with CD4, for cellular entry of HIV-1 in vivo whereas the contribution of other chemokine receptors to HIV disease has not been yet determined. CCR5-specific (R5) viruses predominate during primary HIV-1 infection whereas vir...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Penn ML,Grivel JC,Schramm B,Goldsmith MA,Margolis L

更新日期：1999-01-19 00:00:00

abstract：:The expression of interleukin 2 receptors (IL-2R) is a critical step leading to normal lymphocyte proliferation. Since thymosin fraction 5 (TF5), a thymic hormone preparation, enhances lymphoproliferative responses of human cells, we examined the effects of TF5 on the expression of IL-2R on mitogen-stimulated human ly...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Sztein MB,Serrate SA,Goldstein AL

更新日期：1986-08-01 00:00:00