Evolution of P transposable elements: sequences of Drosophila nebulosa P elements.

abstract：:The phosphodiester bond formation by DNA-dependent RNA-polymerase (RNA nucleotidyltransferase, nucleosidetriphosphate:RNA nucleotidyltransferase, EC 2.7.7.6) can in principle result in retention, inversion, or racemization of configuration at the alpha-phosphorus of the nucleoside 5'-triphosphate being polymerized. As...

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

authors： Eckstein F,Armstrong VW,Sternbach H

更新日期：1976-09-01 00:00:00

abstract：:The detrimental effects of elevated intensities of mid-UV radiation (UVB), a result of stratospheric ozone depletion during the austral spring, on the primary producers of the Antarctic marine ecosystem have been well documented. Here we report that natural populations of Antarctic zooplankton also sustain significant...

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

authors： Malloy KD,Holman MA,Mitchell D,Detrich HW 3rd

更新日期：1997-02-18 00:00:00

abstract：:Recent findings suggest that neurons can efficiently repair oxidatively damaged DNA, and that both DNA damage and repair are enhanced by activation of excitatory glutamate receptors. However, in pathological conditions such as ischemic stroke, excessive DNA damage can trigger the death of neurons. Oxidative DNA damage...

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

authors： Canugovi C,Yoon JS,Feldman NH,Croteau DL,Mattson MP,Bohr VA

更新日期：2012-09-11 00:00:00

abstract：:Entamoeba histolytica is a single cell eukaryote that is the etiologic agent of amoebic colitis. Core promoter elements of E. histolytica protein encoding genes include a TATA-like sequence (GTATTTAAAG/C) at -30, a novel element designated GAAC (GAACT) that has a variable location between TATA and the site of transcri...

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

authors： Singh U,Rogers JB,Mann BJ,Petri WA Jr

更新日期：1997-08-05 00:00:00

abstract：:When fibers of fibrin clots or fragments of fibrinogen pellets are negatively stained they exhibit in the electron microscope characteristic patterns of cross-striations or bands. Those found in pellet material are indistinguishable from those seen in thrombin-induced fibrin fibers. The pattern seen in fibrin from bov...

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

authors： Williams RC

更新日期：1983-03-01 00:00:00

abstract：:We noticed that disease-related amyloidogenic proteins and especially cellular prion proteins have the highest proportion of incompletely desolvated backbone H bonds among soluble proteins. Such bonds are vulnerable to water attack and thus represent structural weaknesses. We have measured the adsorption of proteins o...

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

authors： Fernández A,Berry RS

更新日期：2003-03-04 00:00:00

abstract：:The synaptic vesicle membrane protein synaptotagmin (tagmin) is essential for fast, calcium-dependent, neurotransmitter release and is likely to be the calcium sensor for exocytosis, because of its many calcium-dependent properties. Polyphosphoinositides are needed for exocytosis, but it has not been known why. We now...

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

authors： Schiavo G,Gu QM,Prestwich GD,Söllner TH,Rothman JE

更新日期：1996-11-12 00:00:00

abstract：:Antigen stimulation of mast cells via FcepsilonRI, the high-affinity receptor for IgE, triggers a signaling cascade that requires Ca(2+) mobilization for exocytosis of secretory granules during an allergic response. This study investigates critical signaling components by using mutant RBL mast cells that are defective...

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

authors： Hong-Geller E,Holowka D,Siraganian RP,Baird B,Cerione RA

更新日期：2001-01-30 00:00:00

abstract：:The voltage-gated potassium (Kv) channel Kv1.5 mediates the I(Kur) repolarizing current in human atrial myocytes and regulates vascular tone in multiple peripheral vascular beds. Understanding the complex regulation of Kv1.5 function is of substantial interest because it represents a promising pharmacological target f...

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

authors： Benson MD,Li QJ,Kieckhafer K,Dudek D,Whorton MR,Sunahara RK,Iñiguez-Lluhí JA,Martens JR

更新日期：2007-02-06 00:00:00

abstract：:Two mutants of Balb/c 3T3 cells defective in adhesiveness to substratum have been isolated. After exposure to a mutagen a cell population was treated with prostaglandin E1 and methylisobutylxanthine to elevate the cells 3':5'-cyclic AMP levels and adhesion to the substratum; then, loosley adherent cells were harvested...

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

authors： Pouysségur JM,Pastan I

更新日期：1976-02-01 00:00:00

abstract：:Preferential phosphorylation of specific proteins by cAMP-dependent protein kinase (PKA) may be mediated in part by the anchoring of PKA to a family of A-kinase anchor proteins (AKAPs) positioned in close proximity to target proteins. This interaction is thought to depend on binding of the type II regulatory (RII) sub...

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

authors： Burton KA,Johnson BD,Hausken ZE,Westenbroek RE,Idzerda RL,Scheuer T,Scott JD,Catterall WA,McKnight GS

更新日期：1997-09-30 00:00:00

abstract：:Dual inactivation of PTEN and INK4a/ARF tumor suppressor genes is a common feature observed in a broad spectrum of human cancer types. To validate functional collaboration between these genes in tumor suppression, we examined the biological consequences of Pten and/or Ink4a/Arf deficiency in cells and mice. Relative t...

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

authors： You MJ,Castrillon DH,Bastian BC,O'Hagan RC,Bosenberg MW,Parsons R,Chin L,DePinho RA

更新日期：2002-02-05 00:00:00

abstract：:Developmental hemoglobin switching involves sequential globin gene activations and repressions that are incompletely understood. Earlier observations, described herein, led us to hypothesize that nuclear ferritin is a repressor of the adult beta-globin gene in embryonic erythroid cells. Our data show that a ferritin-f...

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

authors： Broyles RH,Belegu V,DeWitt CR,Shah SN,Stewart CA,Pye QN,Floyd RA

更新日期：2001-07-31 00:00:00

abstract：:Endothelial cells (EC) play a central role in inflammatory immune responses and efficiently induce effector functions in T cells, despite lacking the classical costimulatory ligands CD80 and CD86. By using the mAb HIL-131 we now demonstrate that human inducible costimulator-ligand (ICOS-L), a molecule related to CD80/...

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

authors： Khayyamian S,Hutloff A,Büchner K,Gräfe M,Henn V,Kroczek RA,Mages HW

更新日期：2002-04-30 00:00:00

abstract：:Recent studies have shown that phytoliths are softer than dental enamel but still act as abrasive agents. Thus, phytolith content should be reflected in dental wear. Because native phytoliths show lower indentation hardness than phytoliths extracted by dry ashing, we propose that the hydration state of plant tissue wi...

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

authors： Winkler DE,Schulz-Kornas E,Kaiser TM,De Cuyper A,Clauss M,Tütken T

更新日期：2019-01-22 00:00:00

abstract：:The high resolution 1H and 31P NMR spectra of the (dG-dC)8 duplex have been recorded in low- and high-salt solutions in order to evaluate the structural aspects of the salt-induced transition of oligo(dG-dC) in solution [Pohl, F. M. & Jovin, T. M. (1972) J. Mol. Biol. 67, 375-396]. The NMR data require that the (dG-d...

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

authors： Patel DJ,Canuel LL,Pohl FM

更新日期：1979-06-01 00:00:00

abstract：:Recent climate change has increased arctic soil temperatures and thawed large areas of permafrost, allowing for microbial respiration of previously frozen C. Furthermore, soil destabilization from melting ice has caused an increase in thermokarst failures that expose buried C and release dissolved organic C (DOC) to s...

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

authors： Cory RM,Crump BC,Dobkowski JA,Kling GW

更新日期：2013-02-26 00:00:00

abstract：:For a distribution F on R(p) and a point x in R(p) the simplicial depth D(x), which is the probability that x be inside a random simplex whose vertices are p + 1 independent observations from F, is introduced. D(x) can be viewed as a measure of depth of the point x relative to F, and its empirical version gives rise t...

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

authors： Liu RY

更新日期：1988-03-01 00:00:00

abstract：:We previously isolated from mouse spleen an octapeptide (LSPFPFDL) that in association with the class I major histocompatibility complex protein Ld is recognized by the antigen-specific receptor of an alloreactive CD8+ T-cell clone (2C). Guided by an assay dependent upon the same 2C T-cell receptor, we have now isolat...

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

authors： Udaka K,Tsomides TJ,Walden P,Fukusen N,Eisen HN

更新日期：1993-12-01 00:00:00

abstract：:In over 90% of cervical cancers and cancer-derived cell lines, the p53 tumor suppressor pathway is disrupted by human papillomavirus (HPV). The HPV E6 protein promotes the degradation of p53 and thus inhibits the stabilization and activation of p53 that would normally occur in response to HPV E7 oncogene expression. R...

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

authors： Hietanen S,Lain S,Krausz E,Blattner C,Lane DP

更新日期：2000-07-18 00:00:00

abstract：:Humans have altered natural patterns of fire for millennia, but the impact of human-set fires is thought to have been slight in wet closed-canopy forests. In the South Island of New Zealand, Polynesians (Māori), who arrived 700-800 calibrated years (cal y) ago, and then Europeans, who settled ∼150 cal y ago, used fire...

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

authors： McWethy DB,Whitlock C,Wilmshurst JM,McGlone MS,Fromont M,Li X,Dieffenbacher-Krall A,Hobbs WO,Fritz SC,Cook ER

更新日期：2010-12-14 00:00:00

abstract：:Normal myeloid precursors and MGI(+)D(+) myeloid leukemic cells can be induced to differentiate to mature cells by the normal protein inducer MGI. The sequence of differentiation is the induction of C3 and Fc rosettes, C3 and Fc immune phagocytosis (IP), synthesis and secretion of lysozyme, and formation of mature mac...

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

authors： Lotem J,Sachs L

更新日期：1977-12-01 00:00:00

abstract：:The nitrogen isotopic composition (15N/14N) of forested ecosystems varies systematically worldwide. In tropical forests, which are elevated in 15N relative to temperate biomes, a decrease in ecosystem 15N/14N with increasing rainfall has been reported. This trend is seen in a set of well characterized Hawaiian rainfor...

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

authors： Houlton BZ,Sigman DM,Hedin LO

更新日期：2006-06-06 00:00:00

abstract：:Human serum albumin (HSA) derivatized with cis-aconitic anhydride was covalently coupled to liposomes with a size of approximately 100 nm [polyaconitylated HSA (Aco-HSA) liposomes]. Within 30 min after injection into a rat, Aco-HSA liposomes were completely cleared from the blood and almost exclusively taken up by the...

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

authors： Kamps JA,Morselt HW,Swart PJ,Meijer DK,Scherphof GL

更新日期：1997-10-14 00:00:00

abstract：:Earlier papers demonstrated an extensive genetic exchange among fluorescent Pseudomonads; this one documents for genes specifying enzymes of peripheral dissimilation an extrachromosomal array, segregation, and frequent interstrain transfer. An hypothesis is presented of a general mechanism for the formation and mainte...

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

authors： Rheinwald JG,Chakrabarty AM,Gunsalus IC

更新日期：1973-03-01 00:00:00

abstract：:The results of physicochemical studies of mammalian metallothioneins are summarized and used to propose a model of the protein. The primary structures of all mammalian metallothioneins are very homologous; there are 38 invariant residues and 20 of them are cysteines. The results of UV and CD optical studies indicated ...

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

authors： Boulanger Y,Goodman CM,Forte CP,Fesik SW,Armitage IM

更新日期：1983-03-01 00:00:00

abstract：:The kinetics of hepatic uptake and degradation of sphingomyelin/cholesterol (2:1, M/M) small unilamellar liposomes were investigated in a BALB/c mouse. The tissue distribution of liposomes was determined by scintillation spectrometry. The percentage of intact liposomes in tissues was estimated by the technique of gamm...

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

authors： Hwang KJ,Luk KF,Beaumier PL

更新日期：1980-07-01 00:00:00

abstract：:The human proteome contains a plethora of short linear motifs (SLiMs) that serve as binding interfaces for modular protein domains. Such interactions are crucial for signaling and other cellular processes, but are difficult to detect because of their low to moderate affinities. Here we developed a dedicated approach, ...

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

authors： Ivarsson Y,Arnold R,McLaughlin M,Nim S,Joshi R,Ray D,Liu B,Teyra J,Pawson T,Moffat J,Li SS,Sidhu SS,Kim PM

更新日期：2014-02-18 00:00:00

abstract：:When deprived of D-glucose for 24 hr, chicken embryo fibroblasts exhibit a marked increase in hexose transport activity compared with that of control cells. Scatchard analysis of [3H]cytochalasin B binding to starved cell plasma membranes (46 pmol/mg) indicated a six-fold increase compared with fed cell plasma membran...

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

authors： Pessin JE,Tillotson LG,Yamada K,Gitomer W,Carter-Su C,Mora R,Isselbacher KJ,Czech MP

更新日期：1982-04-01 00:00:00

abstract：:Urinary acidification by the turtle bladder is due to a H+-ATPase that is located in the luminal membrane. The rate of H+ transport is stimulated by an increase in the ambient CO2. Using the fluorescent dye acridine orange, we showed that the mitochondria-rich cell of this equilibrium contains vesicles whose internal ...

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

authors： Gluck S,Cannon C,Al-Awqati Q

更新日期：1982-07-01 00:00:00