Abstract:
:The heterogeneous RNA of the HeLa cell nucleus contains short internal poly(A) sequences which, in contrast to the longer poly(A) sequences at the 3' ends, are not found in messenger RNA of the cytoplasm. A distinct origin for each of these homologous sequences is evident when the effects of actinomycin D and 3'-deoxyadenosine on their biosynthesis are compared. The shorter poly(A) appears to be transcribed, while the longer one does not. A kinetic analysis of the metabolism of each type of poly(A) sequence within different size classes of HnRNA after treatment of the cells with 3'-deoxyadenosine reveals distinctive distribution and metabolism of these sequences and also provides insight into mechanisms proposed for the generation of messenger RNA from these large RNA molecules in the nucleus.
journal_name
Proc Natl Acad Sci U S Aauthors
Nakazato H,Edmonds M,Kopp DWdoi
10.1073/pnas.71.1.200subject
Has Abstractpub_date
1974-01-01 00:00:00pages
200-4issue
1eissn
0027-8424issn
1091-6490journal_volume
71pub_type
杂志文章abstract::Infection of Swiss mouse 3T3FL cells with a clonal isolate of Moloney leukemia virus (MLV-IC) resulted in virus progeny composed of at least three different murine helper oncornaviruses. Each entity was purified in appropriate cells by several sequential terminal dilution isolations and was grouwn to high titers. Besi...
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.72.12.5150
更新日期:1975-12-01 00:00:00
abstract::Seemingly similar individuals often experience drastically different success trajectories, with some repeatedly failing and others consistently succeeding. One explanation is preexisting variability along unobserved fitness dimensions that is revealed gradually through differential achievement. Alternatively, positive...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,随机对照试验
doi:10.1073/pnas.1316836111
更新日期:2014-05-13 00:00:00
abstract::Merkel cell polyomavirus (MCV) contributes to approximately 80% of all Merkel cell carcinomas (MCCs), a highly aggressive neuroendocrine carcinoma of the skin. MCV-positive MCC expresses small T antigen (ST) and a truncated form of large T antigen (LT) and usually contains wild-type p53 (TP53) and RB (RB1). In contras...
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.1818798116
更新日期:2019-01-15 00:00:00
abstract::For centuries ecologists have studied how the diversity and functional traits of plant and animal communities vary across biomes. In contrast, we have only just begun exploring similar questions for soil microbial communities despite soil microbes being the dominant engines of biogeochemical cycles and a major pool 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.1215210110
更新日期:2012-12-26 00:00:00
abstract::We determined the frequency of integrated viral DNA in the livers of three woodchucks chronically infected with the woodchuck hepatitis virus before and during 30 weeks of therapy with the nucleoside analog L-FMAU [1-(2-fluoro-5-methyl-beta, L-arabinofuranosyl)uracil, clevudine]. We found that although viral covalentl...
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.0307422100
更新日期:2004-01-13 00:00:00
abstract::Most studies of cytoskeletal organelles have concentrated on molecular analyses of abundant and biochemically accessible structures. In many of the classical cases, however, the nature of the system chosen has precluded a concurrent genetic analysis. The mitotic spindle of the yeast Saccharomyces cerevisiae is one exa...
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.83.8.2468
更新日期:1986-04-01 00:00:00
abstract::Restriction endonucleases such as EcoRI bind and cleave DNA with great specificity and represent a paradigm for protein-DNA interactions and molecular recognition. Using osmotic pressure to induce water release, we demonstrate the participation of bound waters in the sequence discrimination of substrate DNA by EcoRI. ...
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.95.5.2186
更新日期:1998-03-03 00:00:00
abstract::IL-17-producing CD27(-) γδ cells (γδ(27-) cells) are widely viewed as innate immune cells that make critical contributions to host protection and autoimmunity. However, factors that promote them over IFN-γ-producing γδ(27+) cells are poorly elucidated. Moreover, although human IL-17-producing γδ cells are commonly imp...
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.1204327109
更新日期:2012-10-23 00:00:00
abstract::In a search for a model cell system that might allow studies of the function of the Rho-related GTPase CDC42Hs in human cells, we measured the content and distribution of CDC42Hs in monocytes that were differentiating into macrophages. The total content of this protein increased 5- to 6-fold in phorbol ester-treated 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.91.10.4263
更新日期:1994-05-10 00:00:00
abstract::Chronic psychosocial stress/trauma represents an increasing burden in our modern society and a risk factor for the development of mental disorders, including posttraumatic stress disorder (PTSD). PTSD, in turn, is highly comorbid with a plethora of inflammatory disorders and has been associated with increased bone fra...
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.1819218116
更新日期:2019-04-23 00:00:00
abstract::Seed dormancy is a trait of considerable adaptive significance because it maximizes seedling survival by preventing premature germination under unfavorable conditions. Understanding how seeds break dormancy and initiate growth is also of great agricultural and biotechnological interest. Abscisic acid (ABA) plays prima...
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.081594298
更新日期:2001-04-10 00:00:00
abstract::The pivotal step on the mitochondrial pathway to apoptosis is permeabilization of the mitochondrial outer membrane (MOM) by oligomers of the B-cell lymphoma-2 (Bcl-2) family members Bak or Bax. However, how they disrupt MOM integrity is unknown. A longstanding model is that activated Bak and Bax insert two α-helices, ...
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.1415142111
更新日期:2014-09-30 00:00:00
abstract::The effects of urea and of guanidinium chloride on binding constants in water for 6-(4-tert-butylanilino)-naphthalene-2-sulfonate and of bis(p-tert-butylphenyl) phosphate binding to beta-cyclodextrin and to N,N'-bis(6-beta-cyclo-dextrinyl)imidazolium ion have been determined. Their effects on the water solubility of p...
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.89.15.6916
更新日期:1992-08-01 00:00:00
abstract::The ability to dynamically organize functional nanoparticles (NPs) via the use of environmental triggers (temperature, pH, light, or solvent polarity) opens up important perspectives for rapid and convenient construction of a rich variety of complex assemblies and materials with new structures and functionalities. Her...
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.1714748115
更新日期:2018-02-13 00:00:00
abstract::Unfolded RNase A is known to contain an equilibrium mixture of two forms, a slow-folding form (U(1)) and a fast-folding form (U(2)). If U(1) is produced after unfolding by the slow cis-trans isomerization of proline residues about X-Pro imide bonds, then the formation of U(1) should be catalyzed by strong acids. There...
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.75.10.4764
更新日期:1978-10-01 00:00:00
abstract::Animal mitochondrial DNA (mtDNA) maintains a displacement loop (D loop) at the heavy strand origin of replication. These D loops represent sharply limited synthesis of heavy strands and provide a unique opportunity to examine the termination of DNA synthesis. Direct sizing at the nucleotide level indicates that the 3'...
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.78.10.6116
更新日期:1981-10-01 00:00:00
abstract::The plant kingdom contains vastly untapped natural product chemistry, which has been traditionally explored through the activity-guided approach. Here, we describe a gene-guided approach to discover and engineer a class of plant ribosomal peptides, the branched cyclic lyciumins. Initially isolated from the Chinese wol...
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.1813993115
更新日期:2018-11-13 00:00:00
abstract::beta 1-Adrenergic receptors from turkey erythrocyte membranes have been identified by specific binding of the radiolabeled antagonist (-)-[3H]dihydroalprenolol. These receptors are inactivated by the alkylating agent N-ethylmaleimide when occupied by beta-adrenergic agonists but not when occupied by antagonists or whe...
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.77.7.3801
更新日期:1980-07-01 00:00:00
abstract::Since the development of infectious cDNA clones of viral RNA genomes and the means of delivery of the in vitro-synthesized RNA into cells, alphaviruses have become an attractive system for expression of heterologous genetic information. Alphaviruses replicate exclusively in the cytoplasm, and their genetic material ca...
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.1408677111
更新日期:2014-07-22 00:00:00
abstract::The kinase Cdc2p is a central regulator of entry into and progression through nuclear division during mitosis and meiosis in eukaryotes. Cdc2p is activated at the onset of mitosis by dephosphorylation on tyrosine-15, the phosphorylation status of which is determined mainly by the kinase Wee1p and the phosphatase Cdc25...
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.0702906104
更新日期:2007-09-11 00:00:00
abstract::Cell aggregates are a tool for in vitro studies of morphogenesis, cancer invasion, and tissue engineering. They respond to mechanical forces as a complex rather than simple liquid. To change an aggregate's shape, cells have to overcome energy barriers. If cell shape fluctuations are active enough, the aggregate sponta...
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.0902085106
更新日期:2009-10-13 00:00:00
abstract::Histone methylation has an important role in transcriptional regulation. However, unlike H3K4 and H3K9 methylation, the role of H4K20 monomethylation (H4K20me-1) in transcriptional regulation remains unclear. Here, we show that Wnt3a specifically stimulates H4K20 monomethylation at the T cell factor (TCF)-binding elem...
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.1009353108
更新日期:2011-02-22 00:00:00
abstract::The flux of solvent water coupled to the transit of ions through protein pores is considerable. The effect of this electroosmotic solvent flow on the binding of a neutral molecule [beta-cyclodextrin (betaCD)] to sites within the staphylococcal alpha-hemolysin pore was investigated. Mutant alpha-hemolysin pores were 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.2531778100
更新日期:2003-12-23 00:00:00
abstract::Schaftoside and isoschaftoside are bioactive natural products widely distributed in higher plants including cereal crops and medicinal herbs. Their biosynthesis may be related with plant defense. However, little is known on the glycosylation biosynthetic pathway of these flavonoid di-C-glycosides with different sugar ...
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.2012745117
更新日期:2020-12-01 00:00:00
abstract::A closed duplex DNA molecule relaxed and containing nucleosomes has a different linking number from the same molecule relaxed and without nucleosomes. What does this say about the structure of the nucleosome? A mathematical study of this question is made, representing the DNA molecule by a ribbon. It is shown that 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.75.8.3557
更新日期:1978-08-01 00:00:00
abstract::Plants can recognize and resist invading pathogens by signaling the induction of rapid defense responses. Often these responses are mediated by single dominant resistance genes (R genes). The products of R genes have been postulated to recognize the pathogen and trigger rapid host defense responses. Here we describe i...
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.92.10.4175
更新日期:1995-05-09 00:00:00
abstract::Neuroblastoma-glioma hybrid cells (NG108-15) in suspension accumulate the permeant lipophilic cation [(3)H]tetraphenylphosphonium (TPP(+)) against a concentration gradient. The steady-state level of TPP(+) accumulation is about twice as great in physiological media of low K(+) concentration (i.e., 5 mM K(+)/135 mM Na(...
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.76.2.650
更新日期:1979-02-01 00:00:00
abstract::The GATA factor Serpent (Srp) is required for hemocyte precursor formation during Drosophila hematopoiesis. These blood cell progenitors give rise to two distinct lineages within the developing embryo. Lozenge, a Runx protein homologue, and Glial cells missing-1 and -2 are essential for crystal cell and plasmatocyte p...
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.1635050100
更新日期:2003-09-30 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
pub_type: 杂志文章
doi:10.1073/pnas.022632099
更新日期:2002-02-05 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
pub_type: 杂志文章
doi:10.1073/pnas.0505129102
更新日期:2005-09-27 00:00:00