Inverted-region electron transfer as a mechanism for enhancing photosynthetic solar energy conversion efficiency.

abstract：:Cell-free extracts of nifF and nifJ mutants of Klebsiella pneumoniae are unable to couple acetylene reduction (N2 fixation) by nitrogenase to the oxidation of organic metabolites. However, nifF and nifJ mutants can complement each other in vitro to establish the coupling. This indicates that the products of the nifF a...

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

authors： Nieva-Gómez D,Roberts GP,Klevickis S,Brill WJ

更新日期：1980-05-01 00:00:00

abstract：:Local levels of active thyroid hormone (3,3',5-triiodothyronine) are controlled by the action of activating and inactivating iodothyronine deiodinase enzymes. Deiodinases are selenocysteine-dependent membrane proteins catalyzing the reductive elimination of iodide from iodothyronines through a poorly understood mechan...

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

authors： Schweizer U,Schlicker C,Braun D,Köhrle J,Steegborn C

更新日期：2014-07-22 00:00:00

abstract：:Many Drosophila non-long terminal repeat (LTR) retrotransposons actively transpose into internal, gene-rich regions of chromosomes but do not transpose onto chromosome ends. HeT-A and TART are remarkable exceptions; they form telomeres of Drosophila by repeated transpositions onto the ends of chromosomes and never tra...

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

authors： Rashkova S,Karam SE,Pardue ML

更新日期：2002-03-19 00:00:00

abstract：:The stress inoculation hypothesis presupposes that brief intermittent stress exposure early in life induces the development of subsequent stress resistance in human and nonhuman primates. Rodent studies, however, suggest a role for maternal care rather than stress exposure per se (i.e., the maternal mediation hypothes...

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

authors： Parker KJ,Buckmaster CL,Sundlass K,Schatzberg AF,Lyons DM

更新日期：2006-02-21 00:00:00

abstract：:The high susceptibility of human immunoglobulin D to proteolytic degradation affects its biological function, metabolism, and immunoassay. High-pressure liquid chromatography was used to investigate the mechanism and rate of limited proteolytic cleavage of IgD and also to identify, isolate, and quantify the reaction p...

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

authors： Ishioka N,Takahashi N,Putnam FW

更新日期：1987-01-01 00:00:00

abstract：:Establishment of loss-of-function phenotypes is often a key step in determining the biological function of a gene. We describe a procedure to obtain mutant petunia plants in which a specific gene with known sequence is inactivated by the transposable element dTph1. Leaves are collected from batches of 1000 plants with...

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

authors： Koes R,Souer E,van Houwelingen A,Mur L,Spelt C,Quattrocchio F,Wing J,Oppedijk B,Ahmed S,Maes T

更新日期：1995-08-29 00:00:00

abstract：:Lung cancer is the number one cause of cancer-related deaths in the world. Patients treated with current chemotherapies for non-small-cell lung cancers (NSCLCs) have a survival rate of approximately 15% after 5 years. Novel approaches are needed to treat this disease. We show elevated NAD(P)H:quinone oxidoreductase-1 ...

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

authors： Bey EA,Bentle MS,Reinicke KE,Dong Y,Yang CR,Girard L,Minna JD,Bornmann WG,Gao J,Boothman DA

更新日期：2007-07-10 00:00:00

abstract：:Molecular dynamics simulations show that the desolvation rates of isotopes of Li(+), K(+), Rb(+), Ca(2+), Sr(2+), and Ba(2+) may have a relatively strong dependence on the metal cation mass. This inference is based on the observation that the exchange rate constant, k(wex), for water molecules in the first hydration s...

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

authors： Hofmann AE,Bourg IC,DePaolo DJ

更新日期：2012-11-13 00:00:00

abstract：:For almost a century the plant hormone auxin has been central to theories on apical dominance, whereby the growing shoot tip suppresses the growth of the axillary buds below. According to the classic model, the auxin indole-3-acetic acid is produced in the shoot tip and transported down the stem, where it inhibits bud...

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

authors： Mason MG,Ross JJ,Babst BA,Wienclaw BN,Beveridge CA

更新日期：2014-04-22 00:00:00

abstract：:This paper introduces the use of magnetic field tomography (MFT), a noninvasive technique based on distributed source analysis of magnetoencephalography data, which makes possible the three-dimensional reconstruction of dynamic brain activity in humans. MFT has a temporal resolution better than 1 msec and a spatial ac...

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

authors： Ribary U,Ioannides AA,Singh KD,Hasson R,Bolton JP,Lado F,Mogilner A,Llinás R

更新日期：1991-12-15 00:00:00

abstract：:The expression and integration of membrane proteins into vesicle membranes is a critical step in the design of cell-mimetic biosensors, bioreactors, and artificial cells. While membrane proteins have been integrated into a variety of nonnatural membranes, the effects of the chemical and physical properties of these ve...

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

authors： Jacobs ML,Boyd MA,Kamat NP

更新日期：2019-03-05 00:00:00

abstract：:The role of ornithine decarboxylase (OrnDCase, EC 4.1.1.17) and of the polyamines [putrescine (Put), spermidine (Spd), and spermine (Spm)] in mouse skin tumor promotion was investigated by the use of alpha-difluoromethylornithine (CHF2-Orn), an enzyme-activated irreversible inhibitor of OrnDCase. 12-O-Tetradecanoylpho...

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

authors： Weeks CE,Herrmann AL,Nelson FR,Slaga TJ

更新日期：1982-10-01 00:00:00

abstract：:The mechanism of phosphosylation and dephosphorylation of spectrin from human erythrocyte membranes has been examined under closely physiological conditions. The results support the hypothesis that spectrin is an autophosphorylating and dephosphorylating system. (i) Extraction from ghosts of up to 85% of the kinase (c...

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

authors： Imhof BA,Acha-Orbea HJ,Libermann TA,Reber BF,Lanz JH,Winterhalter KH,Birchmeier W

更新日期：1980-06-01 00:00:00

abstract：:The underpinnings of STAT3 hyperphosphorylation resulting in enhanced signaling and cancer progression are incompletely understood. Loss-of-function mutations of enzymes that dephosphorylate STAT3, such as receptor protein tyrosine phosphatases, which are encoded by the PTPR gene family, represent a plausible mechanis...

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

authors： Lui VW,Peyser ND,Ng PK,Hritz J,Zeng Y,Lu Y,Li H,Wang L,Gilbert BR,General IJ,Bahar I,Ju Z,Wang Z,Pendleton KP,Xiao X,Du Y,Vries JK,Hammerman PS,Garraway LA,Mills GB,Johnson DE,Grandis JR

更新日期：2014-01-21 00:00:00

abstract：:The origins of the five groups of living seed plants, including the single relictual species Ginkgo biloba, are poorly understood, in large part because of very imperfect knowledge of extinct seed plant diversity. Here we describe well-preserved material from the Early Cretaceous of Mongolia of the previously enigmati...

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

authors： Herrera F,Shi G,Ichinnorov N,Takahashi M,Bugdaeva EV,Herendeen PS,Crane PR

更新日期：2017-03-21 00:00:00

abstract：:Ribozymes are RNAs that possess the dual properties of RNA sequence-specific recognition, analogous to conventional antisense molecules, and RNA substrate destruction via site-specific cleavage. The cleavage reaction is catalytic in that more than one substrate molecule is processed per ribozyme molecule. We have desi...

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

authors： Ojwang JO,Hampel A,Looney DJ,Wong-Staal F,Rappaport J

更新日期：1992-11-15 00:00:00

abstract：:Sulfoquinovose (SQ; 6-deoxy-6-sulfoglucose) is the polar head group of the plant sulfolipid SQ-diacylglycerol, and SQ comprises a major proportion of the organosulfur in nature, where it is degraded by bacteria. A first degradation pathway for SQ has been demonstrated recently, a "sulfoglycolytic" pathway, in addition...

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

authors： Felux AK,Spiteller D,Klebensberger J,Schleheck D

更新日期：2015-08-04 00:00:00

abstract：:General control nonderepressible 2 (GCN2) plays a major role in the cellular response to amino acid limitation. Although maintenance of amino acid homeostasis is critical for tumor growth, the contribution of GCN2 to cancer cell survival and proliferation is poorly understood. In this study, we generated GCN2 inhibito...

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

authors： Nakamura A,Nambu T,Ebara S,Hasegawa Y,Toyoshima K,Tsuchiya Y,Tomita D,Fujimoto J,Kurasawa O,Takahara C,Ando A,Nishigaki R,Satomi Y,Hata A,Hara T

更新日期：2018-08-14 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

authors： Yasuhiko Y,Haraguchi S,Kitajima S,Takahashi Y,Kanno J,Saga Y

更新日期：2006-03-07 00:00:00

abstract：:Factor XI (plasma thromboplastin antecedent) deficiency is a blood coagulation abnormality occurring in high frequency in Ashkenazi Jews. Three independent point mutations that result in a blood coagulation abnormality have been identified in the factor XI gene of six unrelated Ashkenazi patients. These mutations eith...

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

authors： Asakai R,Chung DW,Ratnoff OD,Davie EW

更新日期：1989-10-01 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：:Dispersed cell cultures were established from 7- to 9-day postnatal mouse cerebellum. The fibrin slice method was used to obtain a localization of plasminogen activator production to specific cells. Fibrinolytically active cells were small (5- to 8-micrometer diameter), round, and occurred singly or in aggregates. Fib...

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

authors： Krystosek A,Seeds NW

更新日期：1981-12-01 00:00:00

abstract：:Resistance to thyroid hormone (RTH) is most often due to point mutations in the beta-isoform of the thyroid hormone (TH) receptor (TR-beta). The majority of mutations involve the ligand-binding domain, where they block TH binding and receptor function on both stimulatory and inhibitory TH response elements. In contras...

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

authors： Machado DS,Sabet A,Santiago LA,Sidhaye AR,Chiamolera MI,Ortiga-Carvalho TM,Wondisford FE

更新日期：2009-06-09 00:00:00

abstract：:The product of the recA gene of E. coli has been identified by labeling proteins synthesized in UV-treated cells after infection with specialized transducing phages carrying the recA gene. Following infection of UV-treated cells by lambda precA, which carries the recA+ gene, a major protein with a molecular weight of ...

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

authors： McEntee K,Hesse JE,Epstein W

更新日期：1976-11-01 00:00:00

abstract：:A-kinase anchoring proteins (AKAPs) shape second-messenger signaling responses by constraining protein kinase A (PKA) at precise intracellular locations. A defining feature of AKAPs is a helical region that binds to regulatory subunits (RII) of PKA. Mining patient-derived databases has identified 42 nonsynonymous SNPs...

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

authors： Smith FD,Omar MH,Nygren PJ,Soughayer J,Hoshi N,Lau HT,Snyder CG,Branon TC,Ghosh D,Langeberg LK,Ting AY,Santana LF,Ong SE,Navedo MF,Scott JD

更新日期：2018-12-04 00:00:00

abstract：:Species expanding into new habitats as a result of climate change or human introductions will frequently encounter resident competitors. Theoretical models suggest that such interspecific competition can alter the speed of expansion and the shape of expanding range boundaries. However, competitive interactions are rar...

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

authors： Legault G,Bitters ME,Hastings A,Melbourne BA

更新日期：2020-10-27 00:00:00

abstract：:The discipline-wide effort to database the fossil record at the occurrence level has made it possible to estimate marine invertebrate extinction and origination rates with much greater accuracy. The new data show that two biotic mechanisms have hastened recoveries from mass extinctions and confined diversity to a rela...

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

authors： Alroy J

更新日期：2008-08-12 00:00:00

abstract：:We provide here evidence that supports the occurrence of a biologically dormant form of selectin ligand carbohydrate, the sialyl 6-sulfo Lewis X containing modified sialic acid, in human leukocytes. The modification of sialic acid involves first de-N-acetylation of sialic acid moiety through ubiquitous de-N-acetylatio...

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

authors： Mitsuoka C,Ohmori K,Kimura N,Kanamori A,Komba S,Ishida H,Kiso M,Kannagi R

更新日期：1999-02-16 00:00:00

abstract：:We studied regional cerebral blood flow using the H2(15)O method while normal subjects performed four similar tasks involving three-letter word beginnings (stems). Prior to each task, subjects studied a list of words. Local blood flow was then monitored during a 40-sec period while subjects (i) silently viewed word st...

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

authors： Squire LR,Ojemann JG,Miezin FM,Petersen SE,Videen TO,Raichle ME

更新日期：1992-03-01 00:00:00

abstract：:Cryopreservation is widely used to maintain backups of cells as it enables the semipermanent storage of cells. During the freezing process, ice crystals that are generated inside and outside the cells can lethally damage the cells. All conventional cryopreservation methods use at least one cryoprotective agent (CPA) t...

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

authors： Akiyama Y,Shinose M,Watanabe H,Yamada S,Kanda Y

更新日期：2019-04-16 00:00:00