Abstract:
:Replication of plasmid DNA molecules containing the simian virus 40 (SV40) origin of DNA replication has been reconstituted with seven highly purified cellular proteins plus the SV40 large tumor (T) antigen. Initiation of DNA synthesis is absolutely dependent upon T antigen, replication protein A, and the DNA polymerase alpha-primase complex and is stimulated by the catalytic subunit of protein phosphatase 2A. Efficient elongation of nascent chains additionally requires proliferating cell nuclear antigen, replication factor C, DNA topoisomerase I, and DNA polymerase delta. Electron microscopic studies indicate that DNA replication begins at the viral origin and proceeds via intermediates containing two forks that move in opposite directions. These findings indicate that the reconstituted replication reaction has many of the characteristics expected of authentic viral DNA replication.
journal_name
Proc Natl Acad Sci U S Aauthors
Weinberg DH,Collins KL,Simancek P,Russo A,Wold MS,Virshup DM,Kelly TJdoi
10.1073/pnas.87.22.8692subject
Has Abstractpub_date
1990-11-01 00:00:00pages
8692-6issue
22eissn
0027-8424issn
1091-6490journal_volume
87pub_type
杂志文章abstract::The phenotype and antigenic specificity of cells secreting interleukin (IL) 4, IL-6, and interferon gamma was studied in mice during primary and secondary immune responses. T lymphocytes were the major source of interferon gamma, whereas non-B/non-T cells were the dominant source of IL-4 and IL-6 in the spleens of imm...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.7.2534
更新日期:1995-03-28 00:00:00
abstract::In contrast with speciation in terrestrial organisms, marine plankton frequently display gradual morphological change without lineage division (e.g., phyletic gradualism or gradual evolution), which has raised the possibility that a different mode of evolution dominates within pelagic environments. Here, we reexamine ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.0902887106
更新日期:2009-12-15 00:00:00
abstract::We solve a discrete version of the classic Plateau problem, which asks for a minimal surface spanning a given curve. Our algorithm is based on a network-flow formulation that finds minimal slabs, intuitively corresponding to minimal "surfaces" of prescribed thickness. We let the slab thickness approach zero in order t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.19.9235
更新日期:1992-10-01 00:00:00
abstract::White matter stroke is a distinct stroke subtype, accounting for up to 25% of stroke and constituting the second leading cause of dementia. The biology of possible tissue repair after white matter stroke has not been determined. In a mouse stroke model, white matter ischemia causes focal damage and adjacent areas of a...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1615322113
更新日期:2016-12-27 00:00:00
abstract::Interleukin 16 (IL-16) is a chemotactic cytokine that binds to the CD4 receptor and affects the activation of T cells and replication of HIV. It is expressed as a large 67-kDa precursor protein (pro-IL-16) in lymphocytes, macrophages, and mast cells, as well as in airway epithelial cells from asthmatics after challeng...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.4.1541
更新日期:1999-02-16 00:00:00
abstract::After the emergence of pandemic influenza viruses in 1957, 1968, and 2009, existing seasonal viruses were observed to be replaced in the human population by the novel pandemic strains. We have previously hypothesized that the replacement of seasonal strains was mediated, in part, by a population-scale boost in antibod...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1200039109
更新日期:2012-02-14 00:00:00
abstract::The induction of antigen-specific tolerance is critical for the prevention of autoimmunity and maintenance of immune tolerance. In addition to their classical role as sentinels of the immune response-inducing T cell reactivity, dendritic cells (DCs) play an important role in maintaining peripheral tolerance through th...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0504484102
更新日期:2005-09-20 00:00:00
abstract::IFN-alpha/beta plays an essential role in innate immunity against viral and bacterial infection. Among the proteins induced by IFN-alpha/beta are the ubiquitin-like ISG15 protein and its E1- (Ube1L) and E2- (UbcH8) conjugating enzymes, leading to the conjugation of ISG15 to cellular proteins. It is likely that ISG15 c...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0504754102
更新日期:2005-07-19 00:00:00
abstract::It has recently been demonstrated that coupled enzymatic processes may possess, for a particular choice of the state variables, multidimensional inflection points in thermodynamic force-flow space. The conditions for reciprocity in the linear region near such a reference state, which may be far from equilibrium, are o...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.78.7.4314
更新日期:1981-07-01 00:00:00
abstract::The F-box represents a protein motif originally identified as a conserved amino-terminal domain within the Neurospora crassa negative regulator sulfur controller-2. Recently, F-boxes have been found within a number of cell cycle regulatory proteins, where they mediate ubiquitin-driven proteolytic events required for m...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.5.2417
更新日期:1998-03-03 00:00:00
abstract::Changes in the expression of Hox genes have been widely linked to the evolution of animal body plans, but functional demonstrations of this relationship have been impeded by the lack of suitable model organisms. A classic case study involves the repeated evolution of specialized feeding appendages, called maxillipeds,...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0902804106
更新日期:2009-08-18 00:00:00
abstract::To understand the biogeochemical roles of microorganisms in the environment, it is important to determine when and under which conditions they are metabolically active. Bioorthogonal noncanonical amino acid tagging (BONCAT) can reveal active cells by tracking the incorporation of synthetic amino acids into newly synth...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1603757113
更新日期:2016-07-12 00:00:00
abstract::The basidiomycete Ustilago maydis is the causative agent of the disease corn smut. To be pathogenic, strains of U. maydis must be heterozygous for a locus called "b," which appears to control both pathogenicity and sexual development. Two alleles of the b locus of U. maydis were isolated by complementation and hybridi...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.3.978
更新日期:1989-02-01 00:00:00
abstract::Inbred 129 strain mice are predisposed to developing male germ cell tumors (GCTs) of the testes. The inherent genetic defects that underlie male GCT susceptibility in the 129 mouse strain are unknown. GCT incidence is increased in 129 strain males that lack functional p53 protein, and we have used this finding to faci...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.140208197
更新日期:2000-07-18 00:00:00
abstract::Mutations in the DAX-1 [dosage-sensitive sex reversal-adrenal hypoplasia congenita (AHC) critical region on the X chromosome; NR0B1] gene cause X-linked AHC associated with hypogonadotropic hypogonadism. DAX-1 encodes an unusual orphan member of the nuclear hormone receptor superfamily, acting as a transcriptional rep...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.122044099
更新日期:2002-06-11 00:00:00
abstract::UT-1 cells are a clone of Chinese hamster ovary cells that were selected to grow in the presence of compactin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase [mevalonate: NADP+ oxidoreductase (CoA-acylating), EC 1.1.1.34]. These cells have 100- to 1,000-fold more immunoprecipitable reductas...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.79.17.5205
更新日期:1982-09-01 00:00:00
abstract::On April 14, 2010, when meltwaters from the Eyjafjallajökull glacier mixed with hot magma, an explosive eruption sent unusually fine-grained ash into the jet stream. It quickly dispersed over Europe. Previous airplane encounters with ash resulted in sandblasted windows and particles melted inside jet engines, causing ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1015053108
更新日期:2011-05-03 00:00:00
abstract::cDNA clones encoding a glutamic acid-rich protein were isolated from a bovine retina cDNA expression library. The cDNA sequence contained an open reading frame of 1770 base pairs encoding a protein of 590 amino acids (64,509 Da) and untranslated regions of 60 and 490 base pairs at the 5' and 3' ends, respectively. The...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.88.8.3116
更新日期:1991-04-15 00:00:00
abstract::Stopping an action in response to an unexpected event requires both that the event is attended to, and that the action is inhibited. Previous neuroimaging investigations of stopping have failed to adequately separate these cognitive elements. Here we used a version of the widely used Stop Signal Task that controls for...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1000175107
更新日期:2010-03-30 00:00:00
abstract::The recruitment and evolutionary optimization of promiscuous enzymes is key to the rapid adaptation of organisms to changing environments. Our understanding of the precise mechanisms underlying enzyme repurposing is, however, limited: What are the active-site features that enable the molecular recognition of multiple ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1607817115
更新日期:2018-07-31 00:00:00
abstract::In many adult tissues, mesenchymal stem cells (MSCs) are closely associated with perivascular niches and coexpress many markers in common with pericytes. The ability of pericytes to act as MSCs, however, remains controversial. By using genetic lineage tracing, we show that some pericytes differentiate into specialized...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1015449108
更新日期:2011-04-19 00:00:00
abstract::The structure of the catalytically inactive mutant (C215S) of the human protein-tyrosine phosphatase 1B (PTP1B) has been solved to high resolution in two complexes. In the first, crystals were grown in the presence of bis-(para-phosphophenyl) methane (BPPM), a synthetic high-affinity low-molecular weight nonpeptidic s...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.94.25.13420
更新日期:1997-12-09 00:00:00
abstract::The HB-19 pseudopeptide 5[Kpsi(CH(2)N)PR]-TASP, psi(CH(2)N) for reduced peptide bond, is a specific inhibitor of HIV infection in different CD4(+) cell lines and in primary T-lymphocytes and macrophages. It blocks virus-particle attachment to permissive cells by binding and forming a stable complex with nucleolin expr...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.221467298
更新日期:2001-11-20 00:00:00
abstract::The genetic basis for virulence in influenza virus is largely unknown. To explore the mutational basis for increased virulence in the lung, the H3N2 prototype clinical isolate, A/HK/1/68, was adapted to the mouse. Genomic sequencing provided the first demonstration, to our knowledge, that a group of 11 mutations can c...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.111165798
更新日期:2001-06-05 00:00:00
abstract::Extended defects are known to have critical influences in achieving desired material performance. However, the nature of extended defect generation is highly elusive due to the presence of multiple nucleation mechanisms with close energetics. A strategy to design extended defects in a simple and clean way is thus high...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1808812115
更新日期:2018-09-18 00:00:00
abstract::Experiments were designed to determine the interrelationship between cyclic AMP and Ca(2+) during the processes of sperm capacitation and the acrosome reaction. In minimal culture media containing pyruvate and lactate as substrates, guinea pig spermatozoa required a minimum of 1.0-1.5 hr to capacitate in the presence ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.76.11.5699
更新日期:1979-11-01 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
pub_type: 杂志文章
doi:10.1073/pnas.73.11.3979
更新日期:1976-11-01 00:00:00
abstract::Development of effective chemopreventive agents against prostate cancer (CaP) for humans requires conclusive evidence of their efficacy in animal models that closely emulates human disease. The autochthonous transgenic adenocarcinoma of the mouse prostate (TRAMP) model, which spontaneously develops metastatic CaP, is ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.171326098
更新日期:2001-08-28 00:00:00
abstract::The Arabidopsis thaliana SOS1 protein is a putative Na+/H+ antiporter that functions in Na+ extrusion and is essential for the NaCl tolerance of plants. sos1 mutant plants share phenotypic similarities with mutants lacking the protein kinase SOS2 and the Ca2+ sensor SOS3. To investigate whether the three SOS proteins ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.132092099
更新日期:2002-06-25 00:00:00
abstract::The S1-nuclease analysis was used to investigate the pattern of inhibin expression in the rat. In a first series of experiments, expression of the alpha, beta A, and beta B subunits of inhibin were monitored in various tissues from male and female rats. Two observations emerge from these studies. First, expression of ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.85.1.247
更新日期:1988-01-01 00:00:00