Crystal structure of the OpcA integral membrane adhesin from Neisseria meningitidis.

abstract：:Nonenzymatic manganese was first shown to provide protection against superoxide toxicity in vivo in 1981, but the chemical mechanism responsible for this protection subsequently became controversial due to conflicting reports concerning the ability of Mn to catalyze superoxide disproportionation in vitro. In a recent ...

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

authors： Barnese K,Gralla EB,Valentine JS,Cabelli DE

更新日期：2012-05-01 00:00:00

abstract：:Estrogen signaling occurs through at least two distinct molecular pathways: (i) direct binding of liganded estrogen receptors (ERs) to estrogen-responsive DNA elements (EREs) (the "ER/ERE pathway") and (ii) indirect recruitment of liganded ERs to activating protein-1 (AP-1)-responsive DNA elements via heterodimers of ...

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

authors： Cheung E,Acevedo ML,Cole PA,Kraus WL

更新日期：2005-01-18 00:00:00

abstract：:Human cancer cells with a mutated p53 tumor-suppressor gene have a selective growth advantage and may exhibit resistance to ionizing radiation and certain chemotherapeutic agents. To examine the prognostic value of mutations in the p53 gene, a cohort of 90 Midwestern Caucasian breast cancer patients were analyzed with...

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

authors： Kovach JS,Hartmann A,Blaszyk H,Cunningham J,Schaid D,Sommer SS

更新日期：1996-02-06 00:00:00

abstract：:Humans who have inherited the class I major histocompatibility allele HLA-A29 have a markedly increased relative risk of developing the eye disease termed birdshot chorioretinopathy. This disease affecting adults is characterized by symmetrically scattered, small, cream-colored spots in the fundus associated with reti...

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

authors： Szpak Y,Vieville JC,Tabary T,Naud MC,Chopin M,Edelson C,Cohen JH,Dausset J,de Kozak Y,Pla M

更新日期：2001-02-27 00:00:00

abstract：:Surfaces with patterned wettability contrast are important in industrial applications such as heat transfer, water collection, and particle separation. Traditional methods of fabricating such surfaces rely on microfabrication technologies, which are only applicable to certain substrates and are difficult to scale up a...

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

authors： Chen D,McKinley GH,Cohen RE

更新日期：2016-07-19 00:00:00

abstract：:A recA-independent recombinational event is described which results in insertion of an entire plasmid genome at a unique site of another plasmid, and coincident excision of a precisely defined DNA segment originally present at the point of the insertion. The resulting recombinant molecules subsequently can undergo sit...

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

authors： Kopecko DJ,Cohen SN

更新日期：1975-04-01 00:00:00

abstract：:The mechanisms that are essential for the maintenance of nutrient status in breast milk are unclear. Our data demonstrate that the intestine via hypoxia-inducible factor (HIF)-2α is an essential regulatory mechanism for maintaining the quality of breast milk. During lactation, intestinal HIF-2α is highly increased, le...

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

authors： Ramakrishnan SK,Anderson ER,Martin A,Centofanti B,Shah YM

更新日期：2015-07-14 00:00:00

abstract：:Tauopathies are a class of neurodegenerative diseases associated with pathological tau. Despite many advances in our understanding of these diseases, the direct mechanism through which tau contributes to neurodegeneration remains poorly understood. Previously, our laboratory implicated the histone demethylase LSD1 in ...

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

authors： Engstrom AK,Walker AC,Moudgal RA,Myrick DA,Kyle SM,Bai Y,Rowley MJ,Katz DJ

更新日期：2020-11-17 00:00:00

abstract：:Ciliary Neurotrophic Factor (CNTF) was first characterized as a trophic factor for motor neurons in the ciliary ganglion and spinal cord, leading to its evaluation in humans suffering from motor neuron disease. In these trials, CNTF caused unexpected and substantial weight loss, raising concerns that it might produce ...

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

authors： Lambert PD,Anderson KD,Sleeman MW,Wong V,Tan J,Hijarunguru A,Corcoran TL,Murray JD,Thabet KE,Yancopoulos GD,Wiegand SJ

更新日期：2001-04-10 00:00:00

abstract：:Accumulating evidence indicates that epigenetic alterations contribute to exacerbated activation or deregulation of the mechanisms that maintain tolerance to self-antigens in patients with lupus, a systemic autoimmune disease that can be triggered by medications taken to treat a variety of conditions. Here, we tested ...

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

authors： Mazari L,Ouarzane M,Zouali M

更新日期：2007-04-10 00:00:00

abstract：:Global demand for agricultural products such as food, feed, and fuel is now a major driver of cropland and pasture expansion across much of the developing world. Whether these new agricultural lands replace forests, degraded forests, or grasslands greatly influences the environmental consequences of expansion. Althoug...

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

authors： Gibbs HK,Ruesch AS,Achard F,Clayton MK,Holmgren P,Ramankutty N,Foley JA

更新日期：2010-09-21 00:00:00

abstract：:Tregs are essential for maintaining peripheral tolerance, and thus targeting these cells may aid in the treatment of autoimmunity and cancer by enhancing or reducing suppressive functions, respectively. Before these cells can be harnessed for therapeutic purposes, it is necessary to understand how they maintain tolera...

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

authors： Pabbisetty SK,Rabacal W,Volanakis EJ,Parekh VV,Olivares-Villagómez D,Cendron D,Boyd KL,Van Kaer L,Sebzda E

更新日期：2016-08-09 00:00:00

abstract：:The oligomerization of activated D- and L- and racemic guanosine-5'-phosphoro-2-methylimidazole on short templates containing D- and L-deoxycytidylate has been studied. Results obtained with D-oligo(dC)s as templates are similar to those previously reported for experiments with a poly(C) template. When one L-dC or two...

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

authors： Kozlov IA,Pitsch S,Orgel LE

更新日期：1998-11-10 00:00:00

abstract：:Swarming bacteria move in multicellular groups and exhibit adaptive resistance to multiple antibiotics. Analysis of this phenomenon has revealed the protective power of high cell densities to withstand exposure to otherwise lethal antibiotic concentrations. We find that high densities promote bacterial survival, even ...

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

authors： Butler MT,Wang Q,Harshey RM

更新日期：2010-02-23 00:00:00

abstract：:Receptor-mediated endocytosis proceeds by transfer of receptor-ligand complexes from clathrin-coated pits at the cell surface to uncoated endocytic vesicles termed receptosomes (or endosomes). These vesicles have now been purified more than 37-fold based on their content of newly internalized epidermal growth factor. ...

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

authors： Dickson RB,Beguinot L,Hanover JA,Richert ND,Willingham MC,Pastan I

更新日期：1983-09-01 00:00:00

abstract：:Significant attention has focused on the role of low-density lipoprotein (LDL) in the pathogenesis of atherosclerosis. However, recent advances have identified triglyceride-rich lipoproteins [e.g., very LDL (VLDL)] as independent risk predictors for this disease. We have previously demonstrated peroxisome proliferator...

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

authors： Lee CH,Kang K,Mehl IR,Nofsinger R,Alaynick WA,Chong LW,Rosenfeld JM,Evans RM

更新日期：2006-02-14 00:00:00

abstract：:The hypothesis that intracellular Ca2+ is an essential component of the intracellular mechanism of insulin action in the adipocyte was evaluated. Cells were loaded with the Ca2+ chelator quin-2, by preincubating them with quin-2 AM, the tetrakis(acetoxymethyl) ester of quin-2. Quin-2 loading inhibited insulin-stimulat...

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

authors： Pershadsingh HA,Shade DL,Delfert DM,McDonald JM

更新日期：1987-02-01 00:00:00

abstract：:We present an algorithm to generate complete evolutionary profiles that represent the topology of the molecular phylogenetic tree of the homologous group. The method, based on the multidimensional QR factorization of numerically encoded multiple sequence alignments, removes redundancy from the alignments and orders th...

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

authors： Sethi A,O'Donoghue P,Luthey-Schulten Z

更新日期：2005-03-15 00:00:00

abstract：:We have identified, cultured, characterized, and propagated adult pluripotent stem cells (PSC) from a subset of human peripheral blood monocytes. These cells, which in appearance resemble fibroblasts, expand in the presence of macrophage colony-stimulating factor and display monocytic and hematopoietic stem cell marke...

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

authors： Zhao Y,Glesne D,Huberman E

更新日期：2003-03-04 00:00:00

abstract：:Size has a profound effect on the structure of the brain. Many brain structures scale allometrically, that is, their relative size changes systematically as a function of brain size. Here we use independent contrasts analysis to examine the scaling of frontal cortex in 43 species of mammals including 25 primates and 1...

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

authors： Bush EC,Allman JM

更新日期：2004-03-16 00:00:00

abstract：:If a population (species) consists of n haploid lines (subpopulations) which reproduce asexually and each of which is subject to random extinction and subsequent replacement, it is shown that, at equilibrium in which mutational production of new alleles and their random extinction balance each other, the genetic diver...

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

authors： Maruyama T,Kimura M

更新日期：1980-11-01 00:00:00

abstract：:The sterol regulatory element-binding protein (SREBP) family of transcription factors controls the biosynthesis of cholesterol and other lipids, and lipid synthesis is critical for cell growth and proliferation. We were, therefore, interested in the expression and activity of SREBPs during the cell cycle. We found tha...

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

authors： Bengoechea-Alonso MT,Punga T,Ericsson J

更新日期：2005-08-16 00:00:00

abstract：:A cell of the bacterium Escherichia coli was tethered covalently to a glass coverslip by a single flagellum, and its rotation was stopped by using optical tweezers. The tweezers acted directly on the cell body or indirectly, via a trapped polystyrene bead. The torque generated by the flagellar motor was determined by ...

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

authors： Berry RM,Berg HC

更新日期：1997-12-23 00:00:00

abstract：:Despite their importance for biological activity, slower molecular motions beyond the nanosecond range remain poorly understood. We have assembled an unprecedented set of experimental NMR data, comprising up to 27 residual dipolar couplings per amino acid, to define the nature and amplitude of backbone motion in prote...

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

authors： Bouvignies G,Bernadó P,Meier S,Cho K,Grzesiek S,Brüschweiler R,Blackledge M

更新日期：2005-09-27 00:00:00

abstract：:In skeletal muscle, dihydropyridine receptors and dihydropyridine-sensitive Ca2+ channels are preferentially localized in the transverse tubular membranes. Starting with an antigenic membrane fraction enriched in rabbit muscle transverse tubules (T-tubules), several monoclonal antibodies were produced by a fusion of s...

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

authors： Malouf NN,Coronado R,McMahon D,Meissner G,Gillespie GY

更新日期：1987-07-01 00:00:00

abstract：:Absolute pitch (AP) is the rare ability to identify the pitch of a tone without the aid of a reference tone. Understanding both the nature and genesis of AP can provide insights into neuroplasticity in the auditory system. We explored factors that may influence the accuracy of pitch perception in AP subjects both duri...

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

authors： Athos EA,Levinson B,Kistler A,Zemansky J,Bostrom A,Freimer N,Gitschier J

更新日期：2007-09-11 00:00:00

abstract：:The completion of the human genome draft has taken several years and is only the beginning of a period in which large amounts of DNA and RNA sequence information will be required from many individuals and species. Conventional sequencing technology has limitations in cost, speed, and sensitivity, with the result that ...

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

authors： Braslavsky I,Hebert B,Kartalov E,Quake SR

更新日期：2003-04-01 00:00:00

abstract：:Noncompetitive inhibitors of the nicotinic acetylcholine (ACh) receptors suppress cation flux directly by binding in and blocking the open channel or indirectly by stabilizing closed states of the receptor. The lidocaine derivative QX-314 and the acridine derivative quinacrine act directly as open channel blockers, bu...

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

authors： Yu Y,Shi L,Karlin A

更新日期：2003-04-01 00:00:00

abstract：:Endosymbiotic acquisition of bacteria by a protist, with subsequent evolution of the bacteria into mitochondria and plastids, had a transformative impact on eukaryotic biology. Reconstructing events that created a stable association between endosymbiont and host during the process of organellogenesis--including establ...

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

authors： Nowack EC,Grossman AR

更新日期：2012-04-03 00:00:00

abstract：:Mismatch repair contributes to genetic stability, and inactivation of the mammalian pathway leads to tumor development. Mismatch correction occurs by an excision-repair mechanism and has been shown to depend on the 5' to 3' hydrolytic activity exonuclease 1 (Exo1) in eukaryotic cells. However, genetic and biochemical ...

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

authors： Kadyrov FA,Genschel J,Fang Y,Penland E,Edelmann W,Modrich P

更新日期：2009-05-26 00:00:00