Recruitment of cyclin T1/P-TEFb to an HIV type 1 long terminal repeat promoter proximal RNA target is both necessary and sufficient for full activation of transcription.

abstract：:A graph-theoretic condition is given for the existence of stable solutions to the Volterra-Lotka equations. ...

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

authors： Yorke JA,Anderson WN

更新日期：1973-07-01 00:00:00

abstract：:Epithelial barrier disruption is a major cause of inflammatory bowel disease (IBD); however, the mechanism through which epigenetic regulation modulates intestinal epithelial integrity remains largely undefined. Here we show that EZH2, the catalytic subunit of polycomb repressive complex (PRC2), is indispensable for m...

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

authors： Liu Y,Peng J,Sun T,Li N,Zhang L,Ren J,Yuan H,Kan S,Pan Q,Li X,Ding Y,Jiang M,Cong X,Tan M,Ma Y,Fu D,Cai S,Xiao Y,Wang X,Qin J

更新日期：2017-05-09 00:00:00

abstract：:Ca2+ is a powerful inhibitor (Ki is congruent to 16 muM) of basal and prostaglandin E1 (PGE1)-stimulated adenylate cyclase [ATP pyrophosphate-lyase (cyclizing); EC 4.6.1.1] activity in membranes obtained from homogenized human platelets. Ca2+ (but not the ionophore A23,187) decreased V(max) of the reaction without an ...

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

authors： Rodan GA,Feinstein MB

更新日期：1976-06-01 00:00:00

abstract：:DNA vaccines, comprised of plasmid DNA encoding proteins from pathogens, allergens, and tumors, are being evaluated as prophylactic vaccines and therapeutic treatments for infectious diseases, allergies, and cancer; plasmids encoding normal human proteins are likewise being tested as vaccines and treatments for autoim...

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

authors： Liu M,Acres B,Balloul JM,Bizouarne N,Paul S,Slos P,Squiban P

更新日期：2004-10-05 00:00:00

abstract：:A mutation partially suppressing the UV sensitivity caused by recF143 in a uvrA6 background was located at codon 37 of recA where GTG (valine) became ATG (methionine). This mutation, originally named srf-803, was renamed recA803. Little if any suppression of the recF143 defect in UV induction of a lexA regulon promote...

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

authors： Madiraju MV,Templin A,Clark AJ

更新日期：1988-09-01 00:00:00

abstract：:A major challenge in research on executive control is to reveal its functional decomposition into underlying neural mechanisms. A typical assumption is that this decomposition occurs solely through anatomically based dissociations. Here we tested an alternative hypothesis that different cognitive control processes may...

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

authors： Braver TS,Paxton JL,Locke HS,Barch DM

更新日期：2009-05-05 00:00:00

abstract：:Inhibition of eicosanoid formation in larvae of the tobacco hornworm Manduca sexta, using specific inhibitors of phospholipase A2, cyclooxygenase, and lipoxygenase, severely weakened the ability of larvae to clear the bacterium Serratia marscescens from their hemolymph. The reduced capability to remove bacteria is ass...

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

authors： Stanley-Samuelson DW,Jensen E,Nickerson KW,Tiebel K,Ogg CL,Howard RW

更新日期：1991-02-01 00:00:00

abstract：:We have assessed whether retinoic acid (RA) comes from local sources or is available widely to activate gene expression in embryos. We used an RA-responsive indicator cell line, L-C2A5, to localize RA sources. In these cells, an RA-sensitive promoter/lacZ reporter construct used previously by us to produce indicator t...

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

authors： Colbert MC,Linney E,LaMantia AS

更新日期：1993-07-15 00:00:00

abstract：:Molecular adaptation is typically assumed to proceed by sequential fixation of beneficial mutations. In diploids, this picture presupposes that for most adaptive mutations, the homozygotes have a higher fitness than the heterozygotes. Here, we show that contrary to this expectation, a substantial proportion of adaptiv...

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

authors： Sellis D,Callahan BJ,Petrov DA,Messer PW

更新日期：2011-12-20 00:00:00

abstract：:The fluorescent probes acridine orange and oxonol-V were used as indicators of pH gradients (DeltapH) and membrane potential differences (DeltaPsi), respectively, in membrane vesicles believed to be derived from the tonoplast of Beta vulgaris L. Low concentrations of nitrate (1-5 mM) caused a partial dissipation of bo...

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

authors： Blumwald E,Poole RJ

更新日期：1985-06-01 00:00:00

abstract：:Direct cell-cell communication is crucial for many processes in biology, particularly embryogenesis, interactions between hematopoetic cells, and in the nervous system. This communication is often mediated by the binding of receptors to cognate ligands at a cell-cell junction. One such interaction that is very importa...

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

authors： Qi S,Krogsgaard M,Davis MM,Chakraborty AK

更新日期：2006-03-21 00:00:00

abstract：:Energy relaxation in light-harvesting complexes has been extensively studied by various ultrafast spectroscopic techniques, the fastest processes being in the sub-100-fs range. At the same time, much slower dynamics have been observed in individual complexes by single-molecule fluorescence spectroscopy (SMS). In this ...

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

authors： Malý P,Gruber JM,Cogdell RJ,Mančal T,van Grondelle R

更新日期：2016-03-15 00:00:00

abstract：:A method has been developed that enables us to identify intracellular degradation intermediates of fructose-bisphosphate aldolase B (D-fructose-1,6-bisphosphate D-glyceraldehyde-3-phosphate-lyase, EC 4.1.2.13). This method is based on the use of antibody against thoroughly denatured purified aldolase. This antibody ha...

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

authors： Reznick AZ,Rosenfelder L,Shpund S,Gershon D

更新日期：1985-09-01 00:00:00

abstract：:Thioredoxin (Trx) is an intracellular redox protein with extracellular cytokine-like and chemokine-like activities. We show here that, although plasma Trx levels are unrelated to survival of HIV-infected individuals with CD4 cell counts above 200/microl blood, survival is significantly impaired (P = 0.003) when plasma...

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

authors： Nakamura H,De Rosa SC,Yodoi J,Holmgren A,Ghezzi P,Herzenberg LA,Herzenberg LA

更新日期：2001-02-27 00:00:00

abstract：:Incubation of rat calvaria for short times in the presence of a labeled amino acid revealed the existence of a collagen fraction (procollagen) that functions as a biosynthetic precursor of collagen. Procollagen contains an alpha1-like chain (pre-alpha1) that elutes earlier from CM-cellulose than does rat-bone alpha1 a...

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

authors： Bellamy G,Bornstein P

更新日期：1971-06-01 00:00:00

abstract：:For more than a century we have understood that our brain's left hemisphere is the primary site for processing language, yet why this is so has remained more elusive. Using positron emission tomography, we report cerebral blood flow activity in profoundly deaf signers processing specific aspects of sign language in ke...

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

authors： Petitto LA,Zatorre RJ,Gauna K,Nikelski EJ,Dostie D,Evans AC

更新日期：2000-12-05 00:00:00

abstract：:RNA viruses are notorious for their genetic plasticity and propensity to exploit new host-range opportunities, which can lead to the emergence of human disease epidemics such as severe acute respiratory syndrome, AIDS, dengue, and influenza. However, the mechanisms of host-range change involved in most of these viral ...

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

authors： Anishchenko M,Bowen RA,Paessler S,Austgen L,Greene IP,Weaver SC

更新日期：2006-03-28 00:00:00

abstract：:Because xenon NMR is highly sensitive to the local environment, laser-polarized xenon could be a unique probe of living tissues. Realization of clinical and medical science applications beyond lung airspace imaging requires methods of efficient delivery of laser-polarized xenon to tissues, because of the short spin-la...

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

authors： Goodson BM,Song Y,Taylor RE,Schepkin VD,Brennan KM,Chingas GC,Budinger TF,Navon G,Pines A

更新日期：1997-12-23 00:00:00

abstract：:A plasmid that consists of an 812-base-pair segment containing the replication origin of plasmid ColE1 and of a 1240-base-pair segment containing a beta-lactamase gene has been constructed. The plasmid DNA has three principal sites where transcription is initiated in vitro. One is located in the ColE1 segment 555 nucl...

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

authors： Itoh T,Tomizawa J

更新日期：1980-05-01 00:00:00

abstract：:Although adaptor ADAP (FYB) and its binding to SLP-76 has been implicated in TcR-induced "inside-out" signaling for LFA-1 activation in T cells, little is known regarding its role in LFA-1-mediated "outside-in" signaling. In this study, we demonstrate that ADAP and SLP-76-ADAP binding are coupled to LFA-1 costimulatio...

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

authors： Wang H,Wei B,Bismuth G,Rudd CE

更新日期：2009-07-28 00:00:00

abstract：:The β-1,3-glucan chrysolaminarin is the main storage polysaccharide of diatoms. In contrast to plants and green algae, diatoms and most other algal groups do not accumulate storage polysaccharides in their plastids. The diatom Phaeodactylum tricornutum possesses only a single gene encoding a putative β-1,3-glucan synt...

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

authors： Huang W,Haferkamp I,Lepetit B,Molchanova M,Hou S,Jeblick W,Río Bártulos C,Kroth PG

更新日期：2018-05-01 00:00:00

abstract：:The structure of HIV-1 Psi-RNA has been elucidated by a concerted approach combining structural probes with mass spectrometric detection (MS3D), which is not affected by the size and crystallization properties of target biomolecules. Distance constraints from bifunctional cross-linkers provided the information require...

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

authors： Yu ET,Hawkins A,Eaton J,Fabris D

更新日期：2008-08-26 00:00:00

abstract：:Profilin1, a ubiquitously expressed actin-binding protein, plays a critical role in cell migration through actin cytoskeletal regulation. Given the traditional view of profilin1 as a promigratory molecule, it is difficult to reconcile observations that profilin1 is down-regulated in various invasive adenocarcinomas an...

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

authors： Bae YH,Ding Z,Das T,Wells A,Gertler F,Roy P

更新日期：2010-12-14 00:00:00

abstract：:Although sexual selection theory has proved successful in explaining a wide array of male ornaments, the function of ornaments occurring in females is largely unknown. Traditionally, female ornaments have been considered nonfunctional, being merely a genetically correlated response to selection for male ornamentation....

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

authors： Amundsen T,Forsgren E

更新日期：2001-11-06 00:00:00

abstract：:By incorporating a population number regulating mechanism into the formulation of genic selection involving a pair of alleles (A1 and A2) with respective frequencies x and I-x, it is shown that the change of x in one generation is given by deltax = sx(1-x)/W, in which W is the mean absolute selective value (in Wright'...

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

authors： Kimura M

更新日期：1978-04-01 00:00:00

abstract：:Microcalcifications geographically target the location of abnormalities within the breast and are of critical importance in breast cancer diagnosis. However, despite stereotactic guidance, core needle biopsy fails to retrieve microcalcifications in up to 15% of patients. Here, we introduce an approach based on diffuse...

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

authors： Soares JS,Barman I,Dingari NC,Volynskaya Z,Liu W,Klein N,Plecha D,Dasari RR,Fitzmaurice M

更新日期：2013-01-08 00:00:00

abstract：:Copper is an essential micronutrient that plays a central role for a broad range of biological processes. Although there is compelling evidence that the intracellular milieu does not contain any free copper ions, the rapid kinetics of copper uptake and release suggests the presence of a labile intracellular copper poo...

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

authors： Yang L,McRae R,Henary MM,Patel R,Lai B,Vogt S,Fahrni CJ

更新日期：2005-08-09 00:00:00

abstract：:Interphase chromosomes were isolated in good yield from four species of fungi. In no case does the chromatin contain histones such as are characteristic of the chromosomes of other eukaryotic organisms. ...

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

authors： Leighton TJ,Dill BC,Stock JJ,Phillips C

更新日期：1971-03-01 00:00:00

abstract：:Concepts organize the relationship among individual stimuli or events by highlighting shared features. Often, new goals require updating conceptual knowledge to reflect relationships based on different goal-relevant features. Here, our aim is to determine how hippocampal (HPC) object representations are organized and ...

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

authors： Mack ML,Love BC,Preston AR

更新日期：2016-11-15 00:00:00

abstract：:Alternative ribosome subunit proteins are prevalent in the genomes of diverse bacterial species, but their functional significance is controversial. Attempts to study microbial ribosomal heterogeneity have mostly relied on comparing wild-type strains with mutants in which subunits have been deleted, but this approach ...

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

authors： Chen YX,Xu ZY,Ge X,Sanyal S,Lu ZJ,Javid B

更新日期：2020-08-11 00:00:00