The role of iron and copper molecules in the neuronal vulnerability of locus coeruleus and substantia nigra during aging.

abstract：:Encoding ribonuclease H1 (RNase H1) degrades RNA hybridized to DNA, and its function is essential for mitochondrial DNA maintenance in the developing mouse. Here we define the role of RNase H1 in mitochondrial DNA replication. Analysis of replicating mitochondrial DNA in embryonic fibroblasts lacking RNase H1 reveals ...

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

authors： Holmes JB,Akman G,Wood SR,Sakhuja K,Cerritelli SM,Moss C,Bowmaker MR,Jacobs HT,Crouch RJ,Holt IJ

更新日期：2015-07-28 00:00:00

abstract：:We report the presence of protein kinase C (PKC) in ejaculated human sperm as revealed by enzymatic activity assay and indirect immunohistochemistry. PKC is localized in the equatorial segment and in the principal piece of the tail. Addition of phorbol 12-myristate 13-acetate resulted in increased flagellar motility t...

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

authors： Rotem R,Paz GF,Homonnai ZT,Kalina M,Naor Z

更新日期：1990-09-01 00:00:00

abstract：:Saposin A, a heat-stable 16-kDa glycoprotein, was isolated from Gaucher disease spleen and purified to homogeneity. Chemical sequencing from its amino terminus and of peptides obtained by digestion with protease from Staphylococcus aureus strain V-8 demonstrated that saposin A is derived from proteolytic processing of...

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

authors： Morimoto S,Martin BM,Yamamoto Y,Kretz KA,O'Brien JS,Kishimoto Y

更新日期：1989-05-01 00:00:00

abstract：:Nitrogenase is an ATP-requiring enzyme capable of carrying out multielectron reductions of inert molecules. A purified remodeled nitrogenase containing two amino acid substitutions near the site of its FeMo cofactor was recently described as having the capacity to reduce carbon dioxide (CO2) to methane (CH4). Here, we...

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

authors： Fixen KR,Zheng Y,Harris DF,Shaw S,Yang ZY,Dean DR,Seefeldt LC,Harwood CS

更新日期：2016-09-06 00:00:00

abstract：:Collectivistic cultures have been characterized as having harmonious, cooperative ingroup relationships. However, we find evidence that people in collectivistic cultures are more vigilant toward ingroup members, mindful of their possible unethical intentions. Study 1 found that Chinese participants were more vigilant ...

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

authors： Liu SS,Morris MW,Talhelm T,Yang Q

更新日期：2019-07-16 00:00:00

abstract：:Accurate calculations of force generated and of ATP flux, in steady isotonic contractions, are made on a simple, two-state muscle model of the sliding filament type. The objective is to illustrate the proper formulation and use of a complete and self-consistent molecular model of muscle. Otherwise, the model is not me...

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

authors： Chen YD,Hill TL

更新日期：1974-05-01 00:00:00

abstract：:Bicistronic cassettes under control of a single promoter have recently been suggested as useful tools for coordinate expression of two different foreign proteins in mammalian cells. Using the long 5' untranslated region of encephalomyocarditis virus as translational enhancer of the second gene, a bicistronic unit comp...

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

authors： Aran JM,Gottesman MM,Pastan I

更新日期：1994-04-12 00:00:00

abstract：:Coagulation is an innate defense mechanism intended to limit blood loss and trap invading pathogens during infection. However, Staphylococcus aureus has the ability to hijack the coagulation cascade and generate clots via secretion of coagulases. Although many S. aureus have this characteristic, some do not. The popul...

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

authors： Trivedi U,Madsen JS,Everett J,Fell C,Russel J,Haaber J,Crosby HA,Horswill AR,Burmølle M,Rumbaugh KP,Sørensen SJ

更新日期：2018-12-11 00:00:00

abstract：:How cells achieve their final sizes is a pervasive biological question. One strategy to increase cell size is for the cell to amplify its chromosomal DNA content through endoreduplication cycles. Although endoreduplication is widespread in eukaryotes, we know very little about its molecular mechanisms. Successful prog...

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

authors： Sugimoto-Shirasu K,Roberts GR,Stacey NJ,McCann MC,Maxwell A,Roberts K

更新日期：2005-12-20 00:00:00

abstract：:The reported isolation of nanobacteria from human kidney stones raises the intriguing possibility that these microorganisms are etiological agents of pathological extraskeletal calcification [Kajander, E. O. & Ciftçioglu, N. (1998) Proc. Natl. Acad. Sci. USA 95, 8274-8279]. Nanobacteria were previously isolated from F...

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

authors： Cisar JO,Xu DQ,Thompson J,Swaim W,Hu L,Kopecko DJ

更新日期：2000-10-10 00:00:00

abstract：:Climate change due to anthropogenic greenhouse gas emissions is expected to increase the frequency and intensity of precipitation events, which is likely to affect the probability of flooding into the future. In this paper we use river flow simulations from nine global hydrology and land surface models to explore unce...

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

authors： Dankers R,Arnell NW,Clark DB,Falloon PD,Fekete BM,Gosling SN,Heinke J,Kim H,Masaki Y,Satoh Y,Stacke T,Wada Y,Wisser D

更新日期：2014-03-04 00:00:00

abstract：:Myofibril formation was visualized in cultured live cardiomyocytes that were transfected with plasmids expressing green fluorescent protein (GFP) linked to the Z-band protein, alpha-actinin. The expression of this fluorescent protein provided an in vivo label for structures containing alpha-actinin. The GFP-alpha-acti...

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

authors： Dabiri GA,Turnacioglu KK,Sanger JM,Sanger JW

更新日期：1997-08-19 00:00:00

abstract：:Selective harvest of large individuals should alter natural adaptive landscapes and drive evolution toward reduced somatic growth and increased reproductive investment. However, few studies have simultaneously considered the relative importance of artificial and natural selection in driving trait changes in wild popul...

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

authors： Edeline E,Carlson SM,Stige LC,Winfield IJ,Fletcher JM,James JB,Haugen TO,Vøllestad LA,Stenseth NC

更新日期：2007-10-02 00:00:00

abstract：:Genes encoding thymidylate synthetase from Bacillus subtilis bacteriophages were cloned in Escherichia coli. Chimeric plasmids pCD1 and pCD3 were constructed from site-specific endonuclease digests of bacteriophage phi3T DNA cloned in pMB9 in E. coli. Similar cloning techniques with bacteriophage beta22 DNA yielded ch...

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

authors： Duncan CH,Wilson GA,Young FE

更新日期：1978-08-01 00:00:00

abstract：:Novel organismal structures in metazoans are often undergirded by complex gene regulatory networks; as such, understanding the emergence of new structures through evolution requires reconstructing the series of evolutionary steps leading to these underlying networks. Here, we reconstruct the step-by-step assembly of t...

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

authors： Irimia M,Denuc A,Burguera D,Somorjai I,Martín-Durán JM,Genikhovich G,Jimenez-Delgado S,Technau U,Roy SW,Marfany G,Garcia-Fernàndez J

更新日期：2011-03-29 00:00:00

abstract：:Retroviruses evolved from long terminal repeat (LTR) retrotransposons by acquisition of envelope functions, and subsequently reinvaded host genomes. Together, endogenous retroviruses and LTR retrotransposons represent major components of animal, plant, and fungal genomes. Sequences from these elements have been exapte...

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

authors： Dodonova SO,Prinz S,Bilanchone V,Sandmeyer S,Briggs JAG

更新日期：2019-05-14 00:00:00

abstract：:The Bill and Melinda Gates Foundation supports an ambitious portfolio of novel vaccines, drug regimens, and diagnostic tools for tuberculosis (TB). We elicited the expected efficacies and improvements of the novel interventions in discussions with the foundations managing their development. Using an age-structured mat...

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

authors： Abu-Raddad LJ,Sabatelli L,Achterberg JT,Sugimoto JD,Longini IM Jr,Dye C,Halloran ME

更新日期：2009-08-18 00:00:00

abstract：:Congenital malformations now represent the largest single cause of mortality in the infant of the diabetic mother. The mechanism by which diabetes exerts its teratogenic effects is not known. This study evaluated whether arachidonic acid might be involved, a possibility raised by the role of arachidonic acid in palata...

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

authors： Goldman AS,Baker L,Piddington R,Marx B,Herold R,Egler J

更新日期：1985-12-01 00:00:00

abstract：:Circulating peripheral blood cells and disaggregated yolk sac cells were obtained from normal mouse embryos as early as day 9 of gestation, prior to the formation of the fetal liver. These were cultured in vitro in plasma clots or methylcellulose, in the presence of either embryonic fluid or adult spleen cell-conditio...

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

authors： Wong PM,Clarke BJ,Carr DH,Chui DH

更新日期：1982-05-01 00:00:00

abstract：:The Na,K-ATPase contains a binding site for cardiac glycosides, such as ouabain, digoxin, and digitoxin, which is highly conserved among species ranging from Drosophila to humans. Although advantage has been taken of this site to treat congestive heart failure with drugs such as digoxin, it is unknown whether this sit...

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

authors： Dostanic-Larson I,Van Huysse JW,Lorenz JN,Lingrel JB

更新日期：2005-11-01 00:00:00

abstract：:An RNA-directed DNA polymerase was isolated from the peripheral blood leukocytes of a patient with acute myelomonocytic leukemia by successive purification of a particulate cytoplasmic fraction with endogenous, ribonuclease-sensitive DNA polymerase activity. Like RNA-directed DNA polymerase from mammalian type-C virus...

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

authors： Gallagher RE,Todaro GJ,Smith RG,Livingston DM,Gallo RC

更新日期：1974-04-01 00:00:00

abstract：:Fibronectin (FN) forms the primitive fibrillar matrix in both embryos and healing wounds. To study the matrix in living cell cultures, we have constructed a cell line that secretes FN molecules chimeric with green fluorescent protein. These FN-green fluorescent protein molecules were assembled into a typical matrix th...

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

authors： Ohashi T,Kiehart DP,Erickson HP

更新日期：1999-03-02 00:00:00

abstract：:For the emergence of early life, the formation of biopolymers such as RNA is essential. However, the addition of nucleotide monomers to existing oligonucleotides requires millimolar concentrations. Even in such optimistic settings, no polymerization of RNA longer than about 20 bases could be demonstrated. How then cou...

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

authors： Mast CB,Schink S,Gerland U,Braun D

更新日期：2013-05-14 00:00:00

abstract：:We present the first experimental evidence to our knowledge that ingroup relations attenuate core disgust and that this helps explain the ability of groups to coact. In study 1, 45 student participants smelled a sweaty t-shirt bearing the logo of another university, with either their student identity (ingroup conditio...

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

authors： Reicher SD,Templeton A,Neville F,Ferrari L,Drury J

更新日期：2016-03-08 00:00:00

abstract：:An evolutionary framework for viewing the formation, the stability, the organizational structure, and the social dynamics of biological families is developed. This framework is based upon three conceptual pillars: ecological constraints theory, inclusive fitness theory, and reproductive skew theory. I offer a set of 1...

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

authors： Emlen ST

更新日期：1995-08-29 00:00:00

abstract：:To investigate the role of the myosin hinge region in muscle contraction, we examined the contraction characteristics and Mg-ATPase activity of glycerinated muscle fibers prepared from rabbit psoas in the presence and absence of polyclonal antibody directed against the subfragment 2 (S-2) region of myosin. The antibod...

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

authors： Sugi H,Kobayashi T,Gross T,Noguchi K,Karr T,Harrington WF

更新日期：1992-07-01 00:00:00

abstract：:A fundamental mystery of plant cell biology is the occurrence of "stromules," stroma-filled tubular extensions from plastids (such as chloroplasts) that are universally observed in plants but whose functions are, in effect, completely unknown. One prevalent hypothesis is that stromules exchange signals or metabolites ...

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

authors： Brunkard JO,Runkel AM,Zambryski PC

更新日期：2015-08-11 00:00:00

abstract：:We are interested in tracking changes in large-scale data by periodically creating an agglomerative clustering and examining the evolution of clusters (communities) over time. We examine a large real-world data set: the NEC CiteSeer database, a linked network of >250,000 papers. Tracking changes over time requires a c...

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

authors： Hopcroft J,Khan O,Kulis B,Selman B

更新日期：2004-04-06 00:00:00

abstract：:Native cytochrome c (cyt c) has a compact tertiary structure with a hexacoordinated heme iron and functions in electron transport in mitochondria and apoptosis in the cytoplasm. However, the possibility that protein modifications confer additional functions to cyt c has not been explored. Disruption of methionine 80 (...

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

authors： Godoy LC,Muñoz-Pinedo C,Castro L,Cardaci S,Schonhoff CM,King M,Tórtora V,Marín M,Miao Q,Jiang JF,Kapralov A,Jemmerson R,Silkstone GG,Patel JN,Evans JE,Wilson MT,Green DR,Kagan VE,Radi R,Mannick JB

更新日期：2009-02-24 00:00:00

abstract：:Alzheimer's disease is a neurodegenerative disorder characterized by the accumulation of amyloid plaques in the brain. This amyloid primarily contains amyloid-beta (Abeta), a 39- to 43-aa peptide derived from the proteolytic cleavage of the endogenous amyloid precursor protein. The 42-residue-length Abeta peptide (Abe...

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

authors： Zhang R,Hu X,Khant H,Ludtke SJ,Chiu W,Schmid MF,Frieden C,Lee JM

更新日期：2009-03-24 00:00:00