Abstract:
:The infectivity of cloned hepatitis B viral DNA (HBV) has been tested in chimpanzees to identify a fully functional HBV genome and to assess the risk associated with its handling. Only one of two HBV DNA sequence variants tested was shown to be infectious. "Clone purified" virus of predicted nucleotide sequence was produced from the infectious HBV DNA, and the cloned viral genome was identical in structure with naturally occurring HBV. Infection could be initiated independent of whether circular monomeric or plasmid integrated dimeric forms of the viral genome were inoculated, but the infectivity of the DNA depended on liver cell transfection or intrahepatic injection. Intravenous injection of high doses of infectious HBV DNA did not induce hepatitis, suggesting that there is virtually no risk associated with routine laboratory handling of cloned HBV DNA.
journal_name
Proc Natl Acad Sci U S Aauthors
Will H,Cattaneo R,Darai G,Deinhardt F,Schellekens H,Schaller Hdoi
10.1073/pnas.82.3.891subject
Has Abstractpub_date
1985-02-01 00:00:00pages
891-5issue
3eissn
0027-8424issn
1091-6490journal_volume
82pub_type
杂志文章abstract::The cDNA of the gene pds from tomato, encoding the carotenoid biosynthesis enzyme phytoene desaturase, was cloned, and its nucleotide sequence was determined. Cells of Escherichia coli that expressed the tomato pds gene could convert phytoene to zeta-carotene. This result suggests that one polypeptide, the product 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.89.11.4962
更新日期:1992-06-01 00:00:00
abstract::Integrins contain two structurally homologous but distantly related domains: an I-like domain that is present in all beta-subunits and an I domain that is present in some alpha-subunits. Atomic resolution and mutagenesis studies of alpha I domains demonstrate a C-terminal, axial displacement of the alpha7-helix that 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.0307291101
更新日期:2004-02-24 00:00:00
abstract::Factor XI (plasma thromboplastin antecedent) deficiency is a blood coagulation abnormality occurring in high frequency in Ashkenazi Jews. Three independent point mutations that result in a blood coagulation abnormality have been identified in the factor XI gene of six unrelated Ashkenazi patients. These mutations eith...
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.86.20.7667
更新日期:1989-10-01 00:00:00
abstract::The utility of adenovirus (Ad) vectors for gene transduction can be limited by receptor specificity. We developed a gene-delivery vehicle in which the potent Ad5 vector was genetically reengineered to display the mucosal-targeting sigma1 protein of reovirus type 3 Dearing (T3D). A sigma1 construct containing all but 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.0400542101
更新日期:2004-04-20 00:00:00
abstract::For several decades, research into the mechanisms of genetic recombination proceeded without a complete understanding of its cellular function or its place in DNA metabolism. Many lines of research recently have coalesced to reveal a thorough integration of most aspects of DNA metabolism, including recombination. In b...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.131004998
更新日期:2001-07-17 00:00:00
abstract::Synthetic genes for human insulin A and B chains were cloned separately in plasmid pBR322. The cloned synthetic genes were then fused to an Escherichia coli beta-galactosidase gene to provide efficient transcription and translation and a stable precursor protein. The insulin peptides were cleaved from beta-galactosida...
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.76.1.106
更新日期:1979-01-01 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::High levels of D-serine occur in mammalian brain, where it appears to be an endogenous ligand of the glycine site of N-methyl-D-aspartate receptors. In glial cultures of rat cerebral cortex, D-serine is enriched in type II astrocytes and is released upon stimulation with agonists of non-N-methyl-D-aspartate glutamate ...
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.96.2.721
更新日期:1999-01-19 00:00:00
abstract::Using direct percussion, language-competent bonobo-chimpanzees Kanzi and Pan-Banisha produced a significantly wider variety of flint tool types than hitherto reported, and used them task-specifically to break wooden logs or to dig underground for food retrieval. For log breaking, small flakes were rotated drill-like 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.1212855109
更新日期:2012-09-04 00:00:00
abstract::Polyketides represent an extremely diverse class of secondary metabolites often explored for their bioactive traits. These molecules are also attractive building blocks for chemical catalysis and polymerization. However, the use of polyketides in larger scale chemistry applications is stymied by limited titers and yie...
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.1721203115
更新日期:2018-02-27 00:00:00
abstract::The Rhizobium common nod gene products NodABC are involved in the synthesis of the core lipochitooligosaccharide (Nod factor) structure, whereas the products of the host-specific nod genes are necessary for diverse structural modifications, which vary in different Rhizobium species. The sulfate group attached to the R...
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.92.7.2706
更新日期:1995-03-28 00:00:00
abstract::Induction of transformation, cell lethality, and DNA lesions were quantitatively compared in Syrian hamster embryo cells (HEC) treated with three different methylating agents: N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), N-methyl-N-nitrosourea (MNU), or methyl methanesulfonate (MMS). Each induced transformation in a d...
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.82.2.421
更新日期:1985-01-01 00:00:00
abstract::Hormones and nutrients often induce genetic programs via signaling pathways that interface with gene-specific activators. Activation of the cAMP pathway, for example, stimulates cellular gene expression by means of the PKA-mediated phosphorylation of cAMP-response element binding protein (CREB) at Ser-133. Here, we us...
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.0501076102
更新日期:2005-03-22 00:00:00
abstract::The convulsant agent methionine sulfoximine inhibits brain glutamine synthetase irreversibly and the inhibitor becomes bound to the active site of the enzyme as methionine sulfoximine phosphate. Only one of the four isomers of methionine sulfoximine, L-methionine-S-sulfoximine, inhibits glutamine synthetase. In the pr...
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.66.2.500
更新日期:1970-06-01 00:00:00
abstract::Caseinolytic proteases (ClpPs) are large oligomeric protein complexes that contribute to cell homeostasis as well as virulence regulation in bacteria. Although most organisms possess a single ClpP protein, some organisms encode two or more ClpP isoforms. Here, we elucidated the crystal structures of ClpP1 and ClpP2 fr...
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.1219125110
更新日期:2013-07-09 00:00:00
abstract::We examined the origins and functional evolution of the Shaker and KCNQ families of voltage-gated K(+) channels to better understand how neuronal excitability evolved. In bilaterians, the Shaker family consists of four functionally distinct gene families (Shaker, Shab, Shal, and Shaw) that share a subunit structure co...
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.1422941112
更新日期:2015-03-03 00:00:00
abstract::Exocytotic membrane fusion and secretion are promoted by the concerted action of GTP and Ca2+, although the precise site(s) of action in the process are not presently known. However, the calcium-dependent membrane fusion reaction driven by synexin (annexin VII) is an in vitro model for this process, which we have now ...
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.93.20.10797
更新日期:1996-10-01 00:00:00
abstract::We have developed a procedure for purifying highly specific polyclonal antibodies against 5-methylcytosine. These antibodies were used to probe the distribution of 5-methylcytosine among fractionated nucleosomes of mouse cell chromatin. Our results demonstrate that at least 80% of the 5-methylcytosine is localized in ...
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.80.18.5490
更新日期:1983-09-01 00:00:00
abstract::Metallo-β-lactamases (MBLs) hydrolyze almost all β-lactam antibiotics and are unaffected by clinically available β-lactamase inhibitors (βLIs). Active-site architecture divides MBLs into three classes (B1, B2, and B3), complicating development of βLIs effective against all enzymes. Bisthiazolidines (BTZs) are carboxyl...
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.1601368113
更新日期:2016-06-28 00:00:00
abstract::A key energy-saving adaptation to chronic hypoxia that enables cardiomyocytes to withstand severe ischemic insults is hibernation, i.e., a reversible arrest of contractile function. Whereas hibernating cardiomyocytes represent the critical reserve of dysfunctional cells that can be potentially rescued, a lack of a sui...
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.0707778105
更新日期:2008-01-08 00:00:00
abstract::Nipah virus (NiV) and Hendra virus are the type species of the highly pathogenic paramyxovirus genus Henipavirus, which can cause severe respiratory disease and fatal encephalitis infections in humans, with case fatality rates approaching 75%. NiV contains two envelope glycoproteins, the receptor-binding G glycoprotei...
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.0804797105
更新日期:2008-07-22 00:00:00
abstract::A residual sphere is formed by projecting seismic ray travel-time anomalies, relative to a reference Earth model, onto an imaginary sphere around an earthquake. Any dominant slab-like fast band can be determined with spherical harmonic expansion. The technique is useful in detecting trends associated with high-velocit...
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.86.22.8602
更新日期:1989-11-01 00:00:00
abstract::Nuclear bodies are RNA and protein-rich, membraneless organelles that play important roles in gene regulation. The largest and most well-known nuclear body is the nucleolus, an organelle whose primary function in ribosome biogenesis makes it key for cell growth and size homeostasis. The nucleolus and other nuclear bod...
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.1509317112
更新日期:2015-09-22 00:00:00
abstract::N-type Ca2+ channels mediate Ca2+ influx, which initiates fast exocytosis of neurotransmitters at synapses, and they interact directly with the SNARE proteins syntaxin and SNAP-25 (synaptosome-associated protein of 25 kDa) through a synaptic protein interaction (synprint) site in the intracellular loop connecting doma...
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.94.10.5405
更新日期:1997-05-13 00:00:00
abstract::In vivo expression technology (IVET) has been used to identify > 100 Salmonella typhimurium genes that are specifically expressed during infection of BALB/c mice and/or murine cultured macrophages. Induction of these genes is shown to be required for survival in the animal under conditions of the IVET selection. One 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.94.3.934
更新日期:1997-02-04 00:00:00
abstract::Rat liver nuclei pure by enzymatic and electron microscope criteria contain protein kinase C (PKC) that can be activated several hundredfold within 3 min of addition of prolactin or phorbol 12-tetradecanoate 13-acetate. Rat prolactin stimulated PKC maximally at 10(-12) M, whereas ovine prolactin was maximally stimulat...
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.85.22.8649
更新日期:1988-11-01 00:00:00
abstract::The crystal structure of the dimeric gene V protein of bacteriophage f1 was determined using multiwavelength anomalous diffraction on the selenomethionine-containing wild-type and isoleucine-47-->methionine mutant proteins with x-ray diffraction data phased to 2.5 A resolution. The structure of the wild-type protein h...
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.91.6.2071
更新日期:1994-03-15 00:00:00
abstract::An explosion of new information linking activation of cell surface signal initiators to changes in gene expression has recently emerged. The focus of much of this information has centered around the agonist-dependent activation of the mitogen-activated protein (MAP) kinases. Although this intracellular signal transduc...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,评审
doi:10.1073/pnas.90.13.5889
更新日期:1993-07-01 00:00:00
abstract::The levels of c-myc, c-fos, and JE mRNAs accumulate in a biphasic pattern following infection of quiescent BALB/c 3T3 mouse cells with polyomavirus. Maximal levels of c-myc and c-fos mRNAs were seen within 1 hr and were nearly undetectable at 6 hr after infection. At 12 hr after infection mRNA levels were again maxima...
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.84.5.1210
更新日期:1987-03-01 00:00:00
abstract::Thalassemia is a heritable human anemia caused by a variety of mutations that affect expression of the alpha- or the beta-chain of hemoglobin. The expressivity of the phenotype is likely to be influenced by unlinked modifying genes. Indeed, by using a mouse model of alpha-thalassemia, we find that its phenotype is str...
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.96.11.6291
更新日期:1999-05-25 00:00:00