Behavior of hematopoietic stem cells in a large animal.

abstract：:The ATP-dependent enzyme dethiobiotin synthetase from Escherichia coli catalyses the formation of dethiobiotin from CO2 and 7, 8-diaminopelargonic acid. The reaction is initiated by the formation of a carbamate and proceeds through a phosphorylated intermediate, a mixed carbamic phosphoric anhydride. Here, we report t...

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

authors： Käck H,Gibson KJ,Lindqvist Y,Schneider G

更新日期：1998-05-12 00:00:00

abstract：:A low molecular weight inhibitor of cell-free protein synthesis effective at subnanomolar concentrations is formed on incubation of cytoplasmic extracts from interferon-treated cells with double-stranded RNA and ATP. It can be conveniently synthesized by incubating a poly(I).poly(C)-Sepharose-bound enzyme fraction fro...

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

authors： Kerr IM,Brown RE

更新日期：1978-01-01 00:00:00

abstract：:The challenging problem of ultra-high-energy-density, high-efficiency, and small-scale portable power generation is addressed here using a distinctive thermophotovoltaic energy conversion mechanism and chip-based system design, which we name the microthermophotovoltaic (μTPV) generator. The approach is predicted to be...

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

authors： Chan WR,Bermel P,Pilawa-Podgurski RC,Marton CH,Jensen KF,Senkevich JJ,Joannopoulos JD,Soljacic M,Celanovic I

更新日期：2013-04-02 00:00:00

abstract：:High-resolution mapping of quantitative trait loci (QTL) in animals has proved to be difficult because the large effect sizes detected in crosses between inbred strains are often caused by numerous linked QTLs, each of small effect. In a study of fearfulness in mice, we have shown it is possible to fine map small-effe...

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

authors： Mott R,Talbot CJ,Turri MG,Collins AC,Flint J

更新日期：2000-11-07 00:00:00

abstract：:The anti-hapten responses to the dinitrophenyl (Dnp) conjugate of the random linear terpolymers poly(L-Glu,LLys,LPhe), GLphi, or poly(LGlu,LLys,LAla), GLA, are of highly restricted heterogeneity. Thus, individual mice of most responder strains express an average of two to four anti-Dnp clones to Dnp-GLphi or Dnp-GLA, ...

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

authors： Kipps TJ,Benacerraf B,Dorf ME

更新日期：1978-06-01 00:00:00

abstract：:An intermolecular intercalation of base pairs was found at the CA step in the I222 crystal structure of the RNA.DNA hybrid, r(CAAAGAAAAG).d(CTTTTCTTTG), which contains two-thirds of the polypurine tract sequence of HIV-1 with a substitution of cytosine for the initial adenine. This sequence crystallized in both P21212...

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

authors： Han GW,Kopka ML,Langs D,Sawaya MR,Dickerson RE

更新日期：2003-08-05 00:00:00

abstract：:The AG dinucleotide at the 3' splice sites of metazoan nuclear pre-mRNAs plays a critical role in catalytic step II of the splicing reaction. Previous studies have shown that replacement of the guanine by adenine in the AG (AG --> GG) inhibits this step. We find that the second step was even more severely inhibited by...

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

authors： Gaur RK,Beigelman L,Haeberli P,Maniatis T

更新日期：2000-01-04 00:00:00

abstract：:Many insects are dependent on bacterial symbionts that provide essential nutrients (ex. aphid-Buchnera and tsetse-Wiglesworthia associations), wherein the symbionts are harbored in specific cells called bacteriocytes that constitute a symbiotic organ bacteriome. Facultative and parasitic bacterial symbionts like Wolba...

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

authors： Hosokawa T,Koga R,Kikuchi Y,Meng XY,Fukatsu T

更新日期：2010-01-12 00:00:00

abstract：:β-Phosphoglucomutase (βPGM) catalyzes isomerization of β-D-glucose 1-phosphate (βG1P) into D-glucose 6-phosphate (G6P) via sequential phosphoryl transfer steps using a β-D-glucose 1,6-bisphosphate (βG16BP) intermediate. Synthetic fluoromethylenephosphonate and methylenephosphonate analogs of βG1P deliver novel step 1 ...

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

authors： Jin Y,Bhattasali D,Pellegrini E,Forget SM,Baxter NJ,Cliff MJ,Bowler MW,Jakeman DL,Blackburn GM,Waltho JP

更新日期：2014-08-26 00:00:00

abstract：:Human P-glycoprotein (Pgp) confers multidrug resistance to cancer cells by ATP-dependent extrusion of a great many structurally dissimilar hydrophobic compounds. The manner in which Pgp recognizes these different substrates is unknown. The protein shows internal homology between its N- and C-terminal halves, each comp...

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

authors： Dey S,Ramachandra M,Pastan I,Gottesman MM,Ambudkar SV

更新日期：1997-09-30 00:00:00

abstract：:Cyclooxygenase-2 (COX-2) expression is induced by mitogenic and proinflammatory factors. Its overexpression plays a causal role in inflammation and tumorigenesis. COX-2 expression is tightly regulated, but the mechanisms are largely unclear. Here we show the control of COX-2 expression by an endogenous tryptophan meta...

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

authors： Cheng HH,Kuo CC,Yan JL,Chen HL,Lin WC,Wang KH,Tsai KK,Guvén H,Flaberg E,Szekely L,Klein G,Wu KK

更新日期：2012-08-14 00:00:00

abstract：:Pathways and enzymes of fatty acid synthase-mediated, long-even-chain (generally C16-C20) fatty acid synthesis are well studied, and general metabolism involved in short-chain (C4-C7) fatty acid biosynthesis is also understood. In contrast, mechanisms of medium-chain (C8-C14) fatty acid synthesis are unclear. Recent w...

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

authors： Kroumova AB,Xie Z,Wagner GJ

更新日期：1994-11-22 00:00:00

abstract：:Methane emissions in the Arctic are important, and may be contributing to global warming. While methane emission rates from Arctic lakes are well documented, methods are needed to quantify the relative contribution of active layer groundwater to the overall lake methane budget. Here we report measurements of natural t...

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

authors： Paytan A,Lecher AL,Dimova N,Sparrow KJ,Kodovska FG,Murray J,Tulaczyk S,Kessler JD

更新日期：2015-03-24 00:00:00

abstract：:Gene-regulatory networks are ubiquitous in nature and critical for bottom-up engineering of synthetic networks. Transcriptional repression is a fundamental function that can be tuned at the level of DNA, protein, and cooperative protein-protein interactions, necessitating high-throughput experimental approaches for in...

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

authors： Swank Z,Laohakunakorn N,Maerkl SJ

更新日期：2019-03-26 00:00:00

abstract：:We prepared a stable cell line expressing the glucagon receptor to characterize the effect of G(s)-coupled receptor stimulation on extracellular signal-regulated protein kinase 1/2 (ERK1/2) activity. Glucagon treatment of the cell line caused a dose-dependent increase in cAMP concentration, activation of cAMP-dependen...

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

authors： Jiang Y,Cypess AM,Muse ED,Wu CR,Unson CG,Merrifield RB,Sakmar TP

更新日期：2001-08-28 00:00:00

abstract：:Functionally differentiated chicken macrophages were derived by in vitro differentiation of embryonic yolk sac cells and were characterized by several macrophage-specific cell markers. Uniform, infected, virus-producing cultures were obtained after exposure of these macrophages to avian myoblastosis virus (AMV), avian...

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

authors： Durban EM,Boettiger D

更新日期：1981-06-01 00:00:00

abstract：:Voltage-gated sodium (Na(V)) and potassium (K(V)) channels are critical components of neuronal action potential generation and propagation. Here, we report that Na(V)β1 encoded by SCN1b, an integral subunit of Na(V) channels, coassembles with and modulates the biophysical properties of K(V)1 and K(V)7 channels, but no...

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

authors： Nguyen HM,Miyazaki H,Hoshi N,Smith BJ,Nukina N,Goldin AL,Chandy KG

更新日期：2012-11-06 00:00:00

abstract：:Spermatogonia are the male germ stem cells that continuously produce sperm for the next generation. Spermatogenesis is a complicated process that proceeds through mitotic phase of stem cell renewal and differentiation, meiotic phase, and postmeiotic phase of spermiogenesis. Full recapitulation of spermatogenesis in vi...

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

authors： Hong Y,Liu T,Zhao H,Xu H,Wang W,Liu R,Chen T,Deng J,Gui J

更新日期：2004-05-25 00:00:00

abstract：:Eye-opening represents a turning point in the function of the visual cortex. Before eye-opening, the visual cortex is largely devoid of sensory inputs and neuronal activities are generated intrinsically. After eye-opening, the cortex starts to integrate visual information. Here we used in vivo two-photon calcium imagi...

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

authors： Rochefort NL,Garaschuk O,Milos RI,Narushima M,Marandi N,Pichler B,Kovalchuk Y,Konnerth A

更新日期：2009-09-01 00:00:00

abstract：:Aged rats, displaying impairments in spatial learning and memory associated with marked cellular atrophy of forebrain cholinergic neurons, received intracerebroventricular infusions of one of the four neurotrophins nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT-3), or neurotrop...

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

authors： Fischer W,Sirevaag A,Wiegand SJ,Lindsay RM,Björklund A

更新日期：1994-08-30 00:00:00

abstract：:Orai1 and stromal interaction molecule 1 (STIM1) mediate store-operated Ca(2+) entry (SOCE) in immune cells. STIM1, an endoplasmic reticulum (ER) Ca(2+) sensor, detects store depletion and interacts with plasma membrane (PM)-resident Orai1 channels at the ER-PM junctions. However, the molecular composition of these ju...

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

authors： Woo JS,Srikanth S,Nishi M,Ping P,Takeshima H,Gwack Y

更新日期：2016-03-08 00:00:00

abstract：:MAP kinase-interacting kinase 1 and 2 (Mnk1 and Mnk2) are protein-serine/threonine kinases that are activated by ERK or p38 and phosphorylate eIF4E, which is involved in cap-dependent translation initiation. However, Mnk1/2 double knockout (Mnk-DKO) mice show normal cell growth and development despite an absence of eI...

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

authors： Ueda T,Sasaki M,Elia AJ,Chio II,Hamada K,Fukunaga R,Mak TW

更新日期：2010-08-10 00:00:00

abstract：:The conformation of DNA molecules tethered to the surface of a microarray may significantly affect the efficiency of hybridization. Although a number of methods have been applied to determine the structure of the DNA layer, they are not very sensitive to variations in the shape of DNA molecules. Here we describe the a...

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

authors： Moiseev L,Unlü MS,Swan AK,Goldberg BB,Cantor CR

更新日期：2006-02-21 00:00:00

abstract：:The specificity of human skin collagenase and of an enzyme from an invasive tumor were studied by using types I, II, III, IV, and V (AB) collagen as substrates. Human skin collagenase degraded types I, II, and III collagen, producing the characteristic 3/4 and 1/4 cleavage products, but failed to degrade type IV or V ...

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

authors： Liotta LA,Abe S,Robey PG,Martin GR

更新日期：1979-05-01 00:00:00

abstract：:Compartmentalization of biomolecules within lipid membranes is a fundamental requirement of living systems and an essential feature of many pharmaceutical therapies. However, applications of membrane-enclosed solutions of proteins, DNA, and other biologically active compounds have been limited by the difficulty of for...

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

authors： Stachowiak JC,Richmond DL,Li TH,Liu AP,Parekh SH,Fletcher DA

更新日期：2008-03-25 00:00:00

abstract：:Some monocytes normally take up residence in tissues as sessile macrophages, but others differentiate into migratory cells resembling dendritic cells that emigrate to lymph nodes. In an in vitro model of a vessel wall, lipid mediators lysophosphatidic acid and platelet-activating factor, whose signals are implicated i...

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

authors： Llodrá J,Angeli V,Liu J,Trogan E,Fisher EA,Randolph GJ

更新日期：2004-08-10 00:00:00

abstract：:STAT1 is an essential transcription factor for macrophage activation by IFN-gamma and requires phosphorylation of the C-terminal Ser727 for transcriptional activity. In macrophages, Ser727 phosphorylation in response to bacterial lipopolysaccharide (LPS), UV irradiation, or TNF-alpha occurred through a signaling path ...

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

authors： Kovarik P,Stoiber D,Eyers PA,Menghini R,Neininger A,Gaestel M,Cohen P,Decker T

更新日期：1999-11-23 00:00:00

abstract：:Embryonic stem cell-based therapies exhibit great potential for the treatment of Parkinson's disease (PD) because they can significantly rescue PD-like behaviors. However, whether the transplanted cells themselves release dopamine in vivo remains elusive. We and others have recently induced human embryonic stem cells ...

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

authors： Kang X,Xu H,Teng S,Zhang X,Deng Z,Zhou L,Zuo P,Liu B,Liu B,Wu Q,Wang L,Hu M,Dou H,Liu W,Zhu F,Li Q,Guo S,Gu J,Lei Q,Lü J,Mu Y,Jin M,Wang S,Jiang W,Liu K,Wang C,Li W,Zhang K,Zhou Z

更新日期：2014-11-04 00:00:00

abstract：:We have isolated CaKRE9, a gene from Candida albicans, that is a functional homologue of the Saccharomyces cerevisiae KRE9 gene involved in beta-1,6-glucan synthesis. Disruption of the CaKRE9 gene in C. albicans shows that CaKre9p is required for the synthesis or assembly of this fungal polymer. Homozygous null disrup...

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

authors： Lussier M,Sdicu AM,Shahinian S,Bussey H

更新日期：1998-08-18 00:00:00

abstract：:dAn.dTn sequences, otherwise known as A tracts, are hotspots for cis-syn thymine dimer formation and deletion mutations induced by UV light. Such A tracts are also known to bend DNA, suggesting that some biological effects of UV light might be related to the distinctive structure and properties of cis-syn dimer-contai...

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

authors： Wang CI,Taylor JS

更新日期：1991-10-15 00:00:00