Alterations of amino acid repeats in the Escherichia coli hemolysin affect cytolytic activity and secretion.

abstract：:Down syndrome (DS) is the most common form of intellectual disability. The cognitive alterations in DS are thought to depend on brain regions critical for learning and memory such as the prefrontal cortex (PFC) and the hippocampus (HPC). Neuroimaging studies suggest that increased brain connectivity correlates with lo...

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

authors： Alemany-González M,Gener T,Nebot P,Vilademunt M,Dierssen M,Puig MV

更新日期：2020-05-26 00:00:00

abstract：:The dissociation and association of an immobilized preparation of the octameric enzyme porphobilinogen synthase [5-aminolevulinate hydro-lyase (adding 5-aminolevulinate and cyclizing), EC 4.2.1.24] is described. On treatment of the immobilized preparation with 4 M urea, four subunits per octamer are removed which can ...

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

authors： Gurne D,Chen J,Shemin D

更新日期：1977-04-01 00:00:00

abstract：:Much of our understanding of atmospheric secondary organic aerosol (SOA) formation from volatile organic compounds derives from laboratory chamber measurements, including mass yield and elemental composition. These measurements alone are insufficient to identify the chemical mechanisms of SOA production. We present he...

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

authors： Zhang X,McVay RC,Huang DD,Dalleska NF,Aumont B,Flagan RC,Seinfeld JH

更新日期：2015-11-17 00:00:00

abstract：:Human PC4 and the yeast ortholog Sub1 have multiple functions in RNA polymerase II transcription. Genome-wide mapping revealed that Sub1 is present on Pol III-transcribed genes. Sub1 was found to interact with components of the Pol III transcription system and to stimulate the initiation and reinitiation steps in a sy...

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

authors： Tavenet A,Suleau A,Dubreuil G,Ferrari R,Ducrot C,Michaut M,Aude JC,Dieci G,Lefebvre O,Conesa C,Acker J

更新日期：2009-08-25 00:00:00

abstract：:Secondary organic aerosol (SOA) comprises a significant portion of atmospheric particular matter. The impact of particular matter on both human health and global climate has long been recognized. Despite its importance, there are still many unanswered questions regarding the formation and evolution of SOA in the atmos...

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

authors： Chang WL,Griffin RJ,Dabdub D

更新日期：2010-04-13 00:00:00

abstract：:In virtually every real-life situation humans are confronted with complex and cluttered visual environments that contain a multitude of objects. Because of the limited capacity of the visual system, objects compete for neural representation and cognitive processing resources. Previous work has shown that such attentio...

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

authors： Kaiser D,Stein T,Peelen MV

更新日期：2014-07-29 00:00:00

abstract：:Fragment screens for new ligands have had wide success, notwithstanding their constraint to libraries of 1,000-10,000 molecules. Larger libraries would be addressable were molecular docking reliable for fragment screens, but this has not been widely accepted. To investigate docking's ability to prioritize fragments, a...

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

authors： Teotico DG,Babaoglu K,Rocklin GJ,Ferreira RS,Giannetti AM,Shoichet BK

更新日期：2009-05-05 00:00:00

abstract：:Recombinant plasmids containing mutant or wild-type adenovirus serotype 2 EIa genes that produce the 12S mRNA alone, the 13S mRNA alone, or both mRNAs were cotransfected into HeLa cells with plasmids containing the viral EIIa or EIII transcription units. The amount of RNA produced from the EIIa and EIII promoters was ...

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

authors： Leff T,Elkaim R,Goding CR,Jalinot P,Sassone-Corsi P,Perricaudet M,Kédinger C,Chambon P

更新日期：1984-07-01 00:00:00

abstract：:Purified diphtheria toxin is shown to inhibit protein synthesis in Ehrlich-Lettré ascites carcinoma cells in vitro. Protein synthesis in Ehrlich-Lettré cells is at least 10,000 times more sensitive to toxin than protein synthesis in normal mouse spleen or thymus cells. This sensitivity correlates with the observation ...

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

authors： Iglewski BH,Rittenberg MB

更新日期：1974-07-01 00:00:00

abstract：:We provide empirical evidence of immigrants' specialization in skill acquisition well before entering the US labor market. Nationally representative datasets enable studying the academic trajectories of immigrant children, with a focus on high-school course-taking patterns and college major choice. Immigrant children ...

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

authors： Rangel MA,Shi Y

更新日期：2019-01-08 00:00:00

abstract：:Some of the most important impacts of global climate change will be felt among the populations, predominantly in developing countries, referred to as "subsistence" or "smallholder" farmers. Their vulnerability to climate change comes both from being predominantly located in the tropics, and from various socioeconomic,...

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

authors： Morton JF

更新日期：2007-12-11 00:00:00

abstract：:I describe some recent observations of large-scale structure in the galaxy distribution. The best constraints come from two-dimensional galaxy surveys and studies of angular correlation functions. Results from galaxy redshift surveys are much less precise but are consistent with the angular correlations, provided the ...

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

authors： Efstathiou G

更新日期：1993-06-01 00:00:00

abstract：:The acetylcholine receptor is a protein that contains certain critical disulfide bonds. Experiments were designed to determine the role such bonds might play in the physiological activity of the receptor. Modification of the receptor with sodium bisulfite and diamide produced an increase in the time constants of the m...

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

authors： Steinacker A,Zuazaga DC

更新日期：1981-12-01 00:00:00

abstract：:Ler, a homolog of H-NS in enteropathogenic Escherichia coli (EPEC), plays a critical role in the expression of virulence genes encoded by the pathogenic island, locus of enterocyte effacement (LEE). Although Ler acts as an antisilencer of multiple LEE operons by alleviating H-NS-mediated silencing, it represses its ow...

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

authors： Bhat A,Shin M,Jeong JH,Kim HJ,Lim HJ,Rhee JH,Paik SY,Takeyasu K,Tobe T,Yen H,Lee G,Choy HE

更新日期：2014-06-24 00:00:00

abstract：:Before they even speak, infants become attuned to the sounds of the language(s) they hear, processing native phonetic contrasts more easily than nonnative ones. For example, between 6 to 8 mo and 10 to 12 mo, infants learning American English get better at distinguishing English and [l], as in "rock" vs. "lock," relat...

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

authors： Schatz T,Feldman NH,Goldwater S,Cao XN,Dupoux E

更新日期：2021-02-09 00:00:00

abstract：:Two of the most important models to account for the specificity and sensitivity of the T cell receptor (TCR) are the kinetic proofreading and serial ligation models. However, although kinetic proofreading provides a means for individual TCRs to measure accurately the length of time they are engaged and signal appropri...

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

authors： Chan C,George AJ,Stark J

更新日期：2001-05-08 00:00:00

abstract：:Cultured rat embryo cells are resistant to neoplastic transformation by chemical carcinogens unless they are extensively subcultured or infected with a murine leukemia virus (MuLV) first. We found that, in normal cultured cells, MuLV activates expression of rat genes that are the progenitors of sarcoma virus genes, b...

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

authors： Kimball PC,Simon MC,Mishra NK

更新日期：1980-06-01 00:00:00

abstract：:During cardiac trabeculation, cardiomyocytes delaminate from the outermost (compact) layer to form complex muscular structures known as trabeculae. As these cardiomyocytes delaminate, the remodeling of adhesion junctions must be tightly coordinated so cells can extrude from the compact layer while remaining in tight c...

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

authors： Cherian AV,Fukuda R,Augustine SM,Maischein HM,Stainier DY

更新日期：2016-07-05 00:00:00

abstract：:Apolipoprotein E (apoE) secreted by macrophages in the artery wall exerts an important protective effect against the development of atherosclerosis, presumably through its ability to promote lipid efflux. Previous studies have shown that increases in cellular free cholesterol levels stimulate apoE transcription in mac...

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

authors： Laffitte BA,Repa JJ,Joseph SB,Wilpitz DC,Kast HR,Mangelsdorf DJ,Tontonoz P

更新日期：2001-01-16 00:00:00

abstract：:Mature peripheral T cells respond to foreign but not to self-antigens. During development in the thymus, deletion of high-affinity self-reactive immature thymocytes contributes to tolerance of mature T cells. However, double-positive thymocytes are positively selected to survive if they respond to self-peptide-MHC com...

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

authors： Stephen TL,Wilson BS,Laufer TM

更新日期：2012-05-08 00:00:00

abstract：:Microtubule-targeting agents (MTAs) are widely used for treatment of cancer and other diseases, and a detailed understanding of the mechanism of their action is important for the development of improved microtubule-directed therapies. Although there is a large body of data on the interactions of different MTAs with pu...

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

authors： Mohan R,Katrukha EA,Doodhi H,Smal I,Meijering E,Kapitein LC,Steinmetz MO,Akhmanova A

更新日期：2013-05-28 00:00:00

abstract：:Biogeochemical reactions occur unevenly in space and time, but this heterogeneity is often simplified as a linear average due to sparse data, especially in subsurface environments where access is limited. For example, little is known about the spatial variability of groundwater denitrification, an important process in...

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

authors： Kolbe T,de Dreuzy JR,Abbott BW,Aquilina L,Babey T,Green CT,Fleckenstein JH,Labasque T,Laverman AM,Marçais J,Peiffer S,Thomas Z,Pinay G

更新日期：2019-02-12 00:00:00

abstract：:Treatment of 45Ca2+-loaded GH3 pituitary cells with various concentrations of digitonin revealed discrete pools (I and II) of cellular 45Ca2+ defined by differing detergent sensitivities. Markers for cytosol and intracellular organelles indicated that the two 45Ca2+ pools were correlated with the two major cellular Ca...

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

authors： Ronning SA,Heatley GA,Martin TF

更新日期：1982-10-01 00:00:00

abstract：:Activation of eukaryotic class II gene expression involves the formation of a transcription initiation complex that includes RNA polymerase II, general transcription factors, and SRB components of the holoenzyme. Negative regulators of transcription have been described, but it is not clear whether any are general repr...

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

authors： Gadbois EL,Chao DM,Reese JC,Green MR,Young RA

更新日期：1997-04-01 00:00:00

abstract：:Soot particles produced by incomplete combustion processes are one of the major components of urban air pollution. Chemistry at their surfaces lead to the heterogeneous conversion of several key trace gases; for example NO(2) interacts with soot and is converted into HONO, which rapidly photodissociates to form OH in ...

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

authors： Monge ME,D'Anna B,Mazri L,Giroir-Fendler A,Ammann M,Donaldson DJ,George C

更新日期：2010-04-13 00:00:00

abstract：:Arsenate is an abundant oxyanion that, because of its ability to mimic the phosphate group, is toxic to cells. Arsenate reductase (EC; encoded by the arsC gene in bacteria) participates to achieve arsenate resistance in both prokaryotes and yeast by reducing arsenate to arsenite; the arsenite is then exported by a spe...

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

authors： Bennett MS,Guan Z,Laurberg M,Su XD

更新日期：2001-11-20 00:00:00

abstract：:Gene conversion and conversion-associated reciprocal recombination have been studied in various Saccharomyces cerevisiae hybrids. In a sample of 11,023 unselected meiotic tetrads, 907 conversions were observed at the arg4, thr3, his1, and SUP6 loci. Of these conversions, 445 (or 49.1%) were associated with reciprocal ...

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

authors： Hurst DD,Fogel S,Mortimer RK

更新日期：1972-01-01 00:00:00

abstract：:When either the homologous RNA (avian myeloblastosis virus RNA) or a heterologous RNA (poliovirus RNA) was used as a template, the anticomplementary DNA synthesized in vitro by avian myeloblastosis virus reverse transcriptase (RNA-directed DNA nucleotidyltransferase, EC 2.7.7.7) was primed by fragments of the original...

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

authors： Myers JC,Dobkin C,Spiegelman S

更新日期：1980-03-01 00:00:00

abstract：:A 6.1-kilobase insertion into the rudimentary (r) gene was cloned and partially sequenced. The insertion consists of a 703-base-pair (bp) P element next to a 5.4-kilobase single-copy sequence. The normal position of the single-copy sequence is near the tip of the X chromosome. Upon insertion into the r gene, this chim...

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

authors： Tsubota SI,Huong DV

更新日期：1991-02-01 00:00:00

abstract：:The traG protein of the F sex factor is an inner membrane protein with a molecular weight of 116,000. Mutants in traG (or in traN) are able to trigger conjugal DNA replication even though they cannot efficiently form stable mating aggregates with F(-) cells. The traG protein (and the traN protein) probably acts in the...

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

authors： Manning PA,Morelli G,Achtman M

更新日期：1981-12-01 00:00:00