A proposed function for spermine and spermidine: protection of replicating DNA against damage by singlet oxygen.

abstract：:Competition for mates can be a major source of selection, not just on secondary sexual traits but across the genome. Mate competition strengthens selection on males via sexual selection, which typically favors healthy, vigorous individuals and, thus, all genetic variants that increase overall quality. However, recent ...

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

authors： Yun L,Chen PJ,Kwok KE,Angell CS,Rundle HD,Agrawal AF

更新日期：2018-06-26 00:00:00

abstract：:The identification of genes contributing to the adaptation of local populations is of great biological interest. In an attempt to characterize functionally important differences among African and non-African Drosophila melanogaster populations, we surveyed neutral microsatellite variation in an 850-kb genomic sequence...

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

authors： Harr B,Kauer M,Schlötterer C

更新日期：2002-10-01 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 N-methyl-D-aspartate (NMDA) receptor, a subtype of excitatory amino acid receptor, mediates synaptic responses in many regions of the central nervous system. This receptor plays a critical role in the mechanisms of both synaptic plasticity and excitotoxicity. Although these receptors were generally thought to be a...

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

authors： Monaghan DT,Olverman HJ,Nguyen L,Watkins JC,Cotman CW

更新日期：1988-12-01 00:00:00

abstract：:Soil systems are being increasingly exposed to the interactive effects of biological invasions and climate change, with rising temperatures expected to benefit alien over indigenous species. We assessed this expectation for an important soil-dwelling group, the springtails, by determining whether alien species show br...

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

authors： Janion-Scheepers C,Phillips L,Sgrò CM,Duffy GA,Hallas R,Chown SL

更新日期：2018-01-02 00:00:00

abstract：:In adipocytes, adenylate cyclase is positively regulated by beta-adrenergic agents and negatively regulated by adenosine. Incubation of adipocytes with adenosine deaminase relieves the inhibition of adenylate cyclase by destroying the adenosine that the cells release into the medium. When adipocytes are incubated with...

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

authors： Chung FZ,Weber HW,Appleman MM

更新日期：1985-03-01 00:00:00

abstract：:Immunization of strain A mice with p-azophenylarsonate-conjugated protein stimulates B cells that synthesize anti-p-azophenylarsonate antibodies. A large fraction of these cells produce antibodies with variable (V) regions encoded by a single heavy chain V gene segment together with multiple combinations of diversity,...

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

authors： Wysocki L,Manser T,Gefter ML

更新日期：1986-03-01 00:00:00

abstract：:In polyandrous species, fathers benefit from attracting greater maternal investment toward their offspring at the expense of the offspring of other males, while mothers should usually allocate resources equally among offspring. This conflict can lead to an evolutionary arms race between the sexes, manifested through a...

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

authors： Raunsgard A,Opedal ØH,Ekrem RK,Wright J,Bolstad GH,Armbruster WS,Pélabon C

更新日期：2018-11-06 00:00:00

abstract：:HIV type 1 (HIV-1) uses the chemokine receptors CCR5 and CXCR4 as coreceptors for entry into target cells. Here we show that the HIV-1 envelope gp120 (Env) activates multiple ionic signaling responses in primary human macrophages, which are important targets for HIV-1 in vivo. Env from both CCR5-dependent JRFL (R5) an...

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

authors： Liu QH,Williams DA,McManus C,Baribaud F,Doms RW,Schols D,De Clercq E,Kotlikoff MI,Collman RG,Freedman BD

更新日期：2000-04-25 00:00:00

abstract：:Neutron diffraction maps have been used to assign the rotor conformations of the hydroxyl hydrogens in trypsin. Knowledge of these conformations is used to assess the relative importance of steric and electrostatic effects in conferring the H-bonding geometries of these groups. A general finding was that most hydroxyl...

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

authors： Kossiakoff AA,Shpungin J,Sintchak MD

更新日期：1990-06-01 00:00:00

abstract：:Discrete growing spiral modes are calculated, on the basis of principles of stellar dynamics, according to the recently developed asymptotic theory of density waves for spiral structure in galaxies. From the growth rates obtained, it appears likely that several spiral modes coexist in a given disk galaxy. General prop...

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

authors： Bertin G,Lau YY,Lin CC,Mark JW,Sugiyama L

更新日期：1977-11-01 00:00:00

abstract：:Dolichol phosphate mannose (Dol-P-Man), formed upon transfer of Man from GDPMan to Dol-P, is a mannosyl donor in pathways leading to N-glycosylation, glycosyl phosphatidylinositol membrane anchoring, and O-mannosylation of protein. Dol-P-Man synthase is an essential protein in Saccharomyces cerevisiae. We have cloned ...

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

authors： Colussi PA,Taron CH,Mack JC,Orlean P

更新日期：1997-07-22 00:00:00

abstract：:Although advances in microfluidic technology have enabled increasingly sophisticated biosensing and bioassay operations to be performed at the microscale, many of these applications employ such small amounts of charged biomolecules (DNA, proteins, and peptides) that they must first be preconcentrated to a detectable l...

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

authors： Shaikh FA,Ugaz VM

更新日期：2006-03-28 00:00:00

abstract：:An explicitly polarizable force field based exclusively on quantum data is applied to calculations of relative binding affinities of ligands to proteins. Five ligands, differing by replacement of an atom or functional group, in complexes with three serine proteases-trypsin, thrombin, and urokinase-type plasminogen act...

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

authors： Khoruzhii O,Donchev AG,Galkin N,Illarionov A,Olevanov M,Ozrin V,Queen C,Tarasov V

更新日期：2008-07-29 00:00:00

abstract：:Bacillus thuringiensis is a widely used bacterial entomopathogen producing insecticidal toxins, some of which are expressed in insect-resistant transgenic crops. Surprisingly, the killing mechanism of B. thuringiensis remains controversial. In particular, the importance of the septicemia induced by the host midgut mic...

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

authors： Caccia S,Di Lelio I,La Storia A,Marinelli A,Varricchio P,Franzetti E,Banyuls N,Tettamanti G,Casartelli M,Giordana B,Ferré J,Gigliotti S,Ercolini D,Pennacchio F

更新日期：2016-08-23 00:00:00

abstract：:The discrepancy between the structural longitudinal organization of the parallel-fiber system in the cerebellar cortex and the functional mosaic-like organization of the cortex has provoked controversial theories about the flow of information in the cerebellum. We address this issue by characterizing the spatiotempora...

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

authors： Cohen D,Yarom Y

更新日期：1998-12-08 00:00:00

abstract：:Classical eyeblink conditioning is a well-characterized model paradigm that engages the septohippocampal cholinergic system. This form of associative learning is impaired in normal aging and severely disrupted in Alzheimer's disease (AD). Some nicotinic cholinergic receptor subtypes are lost in AD, making the use of n...

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

authors： Woodruff-Pak DS,Vogel RW 3rd,Wenk GL

更新日期：2001-02-13 00:00:00

abstract：:Time courses of 13C labeling from alanine and ethanol in perfused mouse livers have been followed by NMR. The enrichment at specific carbons of glucose, glutamate, glutamine, aspartate, acetate, acetoacetate, beta-hydroxybutyrate, and lactate has been measured. The specific labeling of glutamate in the presence of lab...

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

authors： Cohen SM,Shulman RG,McLaughlin AC

更新日期：1979-10-01 00:00:00

abstract：:A principal goal of cancer nanomedicine is to deliver therapeutics effectively to cancer cells within solid tumors. However, there are a series of biological barriers that impede nanomedicine from reaching target cells. Here, we report a stimuli-responsive clustered nanoparticle to systematically overcome these multip...

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

authors： Li HJ,Du JZ,Du XJ,Xu CF,Sun CY,Wang HX,Cao ZT,Yang XZ,Zhu YH,Nie S,Wang J

更新日期：2016-04-12 00:00:00

abstract：:CPEB, a cytoplasmic polyadenylation element-binding protein, plays an important role in translational control of maternal mRNAs in early animal development. During Xenopus oocyte maturation, CPEB undergoes a Cdc2-mediated phosphorylation- and ubiquitin-dependent degradation that is required for proper entry into meios...

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

authors： Setoyama D,Yamashita M,Sagata N

更新日期：2007-11-13 00:00:00

abstract：:Evolution of an oxygenic atmosphere required primordial life to accommodate the toxicity associated with reactive oxygen species. We have characterized an archaeal antioxidant from the hyperthermophilic acidophile Sulfolobus solfataricus. The amino acid sequence of this approximately 22-kDa protein shares little seque...

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

authors： Wiedenheft B,Mosolf J,Willits D,Yeager M,Dryden KA,Young M,Douglas T

更新日期：2005-07-26 00:00:00

abstract：:Supercritical fluids are a unique class of nonaqueous media in which biocatalytic reactions can occur. The physical properties of supercritical fluids, which include gas-like diffusivities and liquid-like densities, can be predictably controlled with changing pressure. This paper describes how adjustment of pressure, ...

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

authors： Kamat SV,Iwaskewycz B,Beckman EJ,Russell AJ

更新日期：1993-04-01 00:00:00

abstract：:Host species have evolved mechanisms that can inhibit pathogen replication even after a cell has been successfully invaded. Here we show that tripartite-motif protein 21 (TRIM21), a ubiquitously expressed E3 ubiquitin ligase that targets viruses inside the cytosol, protects mice against fatal viral infection. Upon inf...

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

authors： Vaysburd M,Watkinson RE,Cooper H,Reed M,O'Connell K,Smith J,Cruickshanks J,James LC

更新日期：2013-07-23 00:00:00

abstract：:This study challenges the paradigm that salt marsh plants prevent lateral wave-induced erosion along wetland edges by binding soil with live roots and clarifies the role of vegetation in protecting the coast. In both laboratory flume studies and controlled field experiments, we show that common salt marsh plants do no...

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

authors： Feagin RA,Lozada-Bernard SM,Ravens TM,Möller I,Yeager KM,Baird AH

更新日期：2009-06-23 00:00:00

abstract：:The fusiform face area (FFA) is a region of human cortex that responds selectively to faces, but whether it supports a more general function relevant for perceptual expertise is debated. Although both faces and objects of expertise engage many brain areas, the FFA remains the focus of the strongest modular claims and ...

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

authors： McGugin RW,Gatenby JC,Gore JC,Gauthier I

更新日期：2012-10-16 00:00:00

abstract：:Social decisions require evaluation of costs and benefits to oneself and others. Long associated with emotion and vigilance, the amygdala has recently been implicated in both decision-making and social behavior. The amygdala signals reward and punishment, as well as facial expressions and the gaze of others. Amygdala ...

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

authors： Chang SW,Fagan NA,Toda K,Utevsky AV,Pearson JM,Platt ML

更新日期：2015-12-29 00:00:00

abstract：:Cyclophilins are a family of proteins that bind cyclosporin A (CsA) and possess peptidyl-prolyl cis-trans isomerase activity. In addition, they are secreted by activated cells and act in a cytokine-like manner, presumably via signaling through a cell surface cyclophilin receptor. More recently, host-derived cyclophili...

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

authors： Sherry B,Zybarth G,Alfano M,Dubrovsky L,Mitchell R,Rich D,Ulrich P,Bucala R,Cerami A,Bukrinsky M

更新日期：1998-02-17 00:00:00

abstract：:Infection with avian influenza A virus of the H5N1 subtype (isolates A/HK/212/03 and A/HK/213/03) was fatal to one of two members of a family in southern China in 2003. This incident was preceded by lethal outbreaks of H5N1 influenza in waterfowl, which are the natural hosts of these viruses and, therefore, normally h...

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

authors： Guan Y,Poon LL,Cheung CY,Ellis TM,Lim W,Lipatov AS,Chan KH,Sturm-Ramirez KM,Cheung CL,Leung YH,Yuen KY,Webster RG,Peiris JS

更新日期：2004-05-25 00:00:00

abstract：:We introduce a methodology, fluorescence lifetime imaging (FLIM), in which the contrast depends on the fluorescence lifetime at each point in a two-dimensional image and not on the local concentration and/or intensity of the fluorophore. We used FLIM to create lifetime images of NADH when free in solution and when bou...

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

authors： Lakowicz JR,Szmacinski H,Nowaczyk K,Johnson ML

更新日期：1992-02-15 00:00:00

abstract：:Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a key transcriptional regulator for antioxidant and anti-inflammation enzymes that binds to its endogenous inhibitor protein, Kelch-like ECH (erythroid cell-derived protein with CNC homology)-associated protein 1, in the cytoplasm under normal conditions. Various e...

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

authors： Kim SB,Pandita RK,Eskiocak U,Ly P,Kaisani A,Kumar R,Cornelius C,Wright WE,Pandita TK,Shay JW

更新日期：2012-10-23 00:00:00