Abstract:
:Efficient expression of human T-cell leukemia virus type I (HTLV-I) genes requires both host and viral proteins and is dependent on DNA sequences in the proviral long terminal repeats (LTRs). We have used DNase I-protection assays (footprinting) to construct a map of protein-DNA interactions over a 250-nucleotide region of the LTR upstream of the start site for viral RNA synthesis. We find that a host factor (host expression factor 1, or HEF-1) binds to the imperfect 21-nucleotide repeats that have previously been implicated in HTLV-I gene expression. HEF-1 binding activity is present in preparations from both lymphoid and nonlymphoid cell lines. However, the boundaries of the protected regions and the presence of a flanking DNase-hypersensitive site vary with cell type. Several regions of binding are detected in addition to the HEF-1 sites, including a complex group of sites 40-90 nucleotides upstream of the RNA start site. A comparison of HTLV-I-transformed T lymphocytes that do and do not express the viral trans-activating protein p40xI shows that none of the observed features of the DNase I footprint pattern correlate directly with the presence of this protein in the extract. These results suggest (i) that the primary recognition of promoter elements in the HTLV-I LTR involves specific interactions with host-cell proteins and (ii) that p40xI influences the activity of one or more of these proteins, rather than interacting directly with the DNA.
journal_name
Proc Natl Acad Sci U S Aauthors
Nyborg JK,Dynan WS,Chen IS,Wachsman Wdoi
10.1073/pnas.85.5.1457subject
Has Abstractpub_date
1988-03-01 00:00:00pages
1457-61issue
5eissn
0027-8424issn
1091-6490journal_volume
85pub_type
杂志文章abstract::Alternaria solani, the causal agent of early blight disease in potato, produces two host-specific, lipidlike toxins in culture. Both compounds are required in the leaf bioassay for the elicitation of typical early blight symptoms, but the compounds are individually inactive. The procedures for the preparation of both ...
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.75.10.4935
更新日期:1978-10-01 00:00:00
abstract::In 1950, John Nash contributed a remarkable one-page PNAS article that defined and characterized a notion of equilibrium for n- person games. This notion, now called the "Nash equilibrium," has been widely applied and adapted in economics and other behavioral sciences. Indeed, game theory, with the Nash equilibrium as...
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.0308738101
更新日期:2004-03-23 00:00:00
abstract::Although heparin and low-molecular-weight heparins (LMWH) have been widely used clinically as anticoagulants, their broader use has been limited by the lack of noninvasive delivery methods for this class of molecules. In this study, we demonstrate an efficient, rapid, and reproducible delivery system for heparin throu...
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.0402891101
更新日期:2004-06-29 00:00:00
abstract::We show that the motion of a slightly compressible fluid is near that of an incompressible fluid. That is, for a given initial velocity field, the motion of a compressible fluid with large sound speed is near to that of an idealized incompressible fluid. We consider the compressible fluid motion in Lagrangian coordina...
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.72.2.539
更新日期:1975-02-01 00:00:00
abstract::We have determined the volume and location of hippocampal tissue required for normal acquisition of a spatial memory task. Ibotenic acid was used to make bilateral symmetric lesions of 20-100% of hippocampal volume. Even a small transverse block (minislab) of the hippocampus (down to 26% of the total) could support sp...
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.92.21.9697
更新日期:1995-10-10 00:00:00
abstract::The production of hybridomas between immunologically activated T cells and malignant T-cell lines offers a potentially unlimited source of soluble T-cell-derived products. Recently, human T-T hybrids have been described; however, their use has been hampered by slow growth and chromosomal instability due at least in pa...
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.79.23.7484
更新日期:1982-12-01 00:00:00
abstract::We identified a viral IL-10 homolog encoded by an ORF (UL111a) within the human cytomegalovirus (CMV) genome, which we designated cmvIL-10. cmvIL-10 can bind to the human IL-10 receptor and can compete with human IL-10 for binding sites, despite the fact that these two proteins are only 27% identical. cmvIL-10 require...
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.97.4.1695
更新日期:2000-02-15 00:00:00
abstract::Cancer cells are characterized by genetic mutations that deregulate cell proliferation and suppress cell death. To arrest the uncontrolled replication of malignant cells, conventional chemotherapies systemically disrupt cell division, causing diverse and often severe side effects as a result of collateral damage to no...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,收录出版
doi:10.1073/pnas.1006377107
更新日期:2010-09-28 00:00:00
abstract::Noniridescent coloration by the spongy keratin in parrot feather barbs has fascinated scientists. Nonetheless, its ultimate origin remains as yet unanswered, and a quantitative structural and optical description is still lacking. Here we report on structural and optical characterizations and numerical simulations of 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.1204383109
更新日期:2012-07-03 00:00:00
abstract::Human cDNA clones encoding a structure-specific recognition protein, SSRP1, that binds specifically to DNA modified with cisplatin have been isolated and characterized. The SSRP1 gene maps to human chromosome 11q12. The cDNA clones, obtained by using partial-length cDNAs described previously, predict an 81-kDa protein...
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.89.6.2307
更新日期:1992-03-15 00:00:00
abstract::Incubation of rat calvaria for short times in the presence of a labeled amino acid revealed the existence of a collagen fraction (procollagen) that functions as a biosynthetic precursor of collagen. Procollagen contains an alpha1-like chain (pre-alpha1) that elutes earlier from CM-cellulose than does rat-bone alpha1 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.68.6.1138
更新日期:1971-06-01 00:00:00
abstract::Proopiomelanocortin (POMC), a major pituitary product, is also present in the adult mouse testis. We have shown previously that POMC mRNAs are most abundant in a subpopulation of Leydig cells associated with tubules in specific stages of the cycle of the seminiferous epithelium. In the present study, we examined the e...
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.84.6.1600
更新日期:1987-03-01 00:00:00
abstract::Type 2 diabetes mellitus (T2DM) is strongly associated with obesity in most, but not all, ethnic groups, suggesting important ethnic differences in disease susceptibility. Although it is clear that insulin resistance plays a major role in the pathogenesis of T2DM and that insulin resistance is strongly associated with...
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.0608537103
更新日期:2006-11-28 00:00:00
abstract::Aberrations in the T cell repertoire with the emergence of oligoclonal populations have been described in patients with rheumatoid arthritis (RA). However, the extent of the repertoire perturbations as well as the underlying mechanisms are not known. We now have examined the diversity of the peripheral CD4 T cell repe...
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.95.24.14447
更新日期:1998-11-24 00:00:00
abstract::By using single-molecule multiparameter fluorescence detection, fluorescence resonance energy transfer experiments, and newly developed data analysis methods, this study demonstrates directly the existence of three structurally distinct forms of reverse transcriptase (RT):nucleic acid complexes in solution. Single-mol...
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.0434003100
更新日期:2003-02-18 00:00:00
abstract::Rhythmic, spontaneously pulsating cardiac cells cultured from newborn rats are immediately stimulated to beat faster by addition of a number of tubulin-binding agents but not by their non-tubulin-binding analogues. The tubulin-binding agents tested include vinblastine, vincristine, navelbine, two analogs of vinblastin...
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.89.4.1256
更新日期:1992-02-15 00:00:00
abstract::Control of transcription and enzyme activities are two interwoven regulatory systems essential for the function of a metabolic node. Saccharomyces cerevisiae strains differing in enzyme activities at the chorismate branch point of aromatic amino acid biosynthesis were constructed by recombinant DNA technology. Express...
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.240469697
更新日期:2000-12-05 00:00:00
abstract::Understanding Hadean (>4 Ga) Earth requires knowledge of its crust. The composition of the crust and volatiles migrating through it directly influence the makeup of the atmosphere, the composition of seawater, and nutrient availability. Despite its importance, there is little known and less agreed upon regarding the n...
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.1720880115
更新日期:2018-06-19 00:00:00
abstract::Measurements of the water proton spinlattice relaxation (T(1)) in 106 human tumors confirms earlier results with animals [Damadian, R. (1971) Science 171, 1151-1153]. T(1) of all the tumors studied were significantly longer than T(1) of the corresponding normal tissues. Mean standard error and range were reported 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.71.4.1471
更新日期:1974-04-01 00:00:00
abstract::Normal as well as Rous sarcoma virus-infected chicken pectoral and chicken embryo fibroblasts proliferate actively in a plasma containing medium of physiological ion concentrations (Ca2+, 1.2 mM; Mg2+, 0.7 mM). Reduction of medium calcium and magnesium concentrations is necessary to achieve selective quiescence of nor...
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.77.11.6606
更新日期:1980-11-01 00:00:00
abstract::Humans are consciously aware of some memories and can make verbal reports about these memories. Other memories cannot be brought to consciousness, even though they influence behavior. This conspicuous difference in access to memories is central in taxonomies of human memory systems but has been difficult to document 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.071600998
更新日期:2001-04-24 00:00:00
abstract::Since its discovery in 1907, polyploidy has been recognized as an important phenomenon in vascular plants, and several lines of evidence indicate that most, if not all, plant species ultimately have a polyploid ancestry. However, previous estimates of the frequency of polyploid speciation suggest that the formation an...
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.0811575106
更新日期:2009-08-18 00:00:00
abstract::A form of autosomal dominant juvenile myoclonic epilepsy is caused by a nonconservative missense mutation, A322D, in the GABAA receptor alpha1 subunit M3 transmembrane helix. We reported previously that the A322D mutation reduced total and surface alpha1(A322D) subunit protein and that residual alpha1(A322D) subunit 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.0700163104
更新日期:2007-08-07 00:00:00
abstract::Most HLA haplotypes carry two expressed DR beta-chain genes; in the DR4 haplotype, the polymorphic locus has been called DR beta 1 and the apparently nonpolymorphic locus has been called DR beta 2. We have isolated nearly full-length DR beta-chain cDNA clones representing each of these two loci from a cell line homozy...
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.84.1.209
更新日期:1987-01-01 00:00:00
abstract::Compressional waves that sample the lowermost mantle west of Central America show a rapid change in travel times of up to 4 s over a sampling distance of 300 km and a change in waveforms. The differential travel times of the PKP waves (which traverse Earth's core) correlate remarkably well with predictions for S-wave ...
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.0609143103
更新日期:2007-01-02 00:00:00
abstract::Gel-forming mucins, the primary macromolecular components of airway mucus, facilitate airway clearance by mucociliary transport. In cystic fibrosis (CF) altered mucus properties impair mucociliary transport. Airways primarily secrete two closely related gel-forming mucins, MUC5B and MUC5AC. However, their morphologic ...
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.1703228114
更新日期:2017-06-27 00:00:00
abstract::Understanding the different categories of facial expressions of emotion regularly used by us is essential to gain insights into human cognition and affect as well as for the design of computational models and perceptual interfaces. Past research on facial expressions of emotion has focused on the study of six basic 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.1322355111
更新日期:2014-04-15 00:00:00
abstract::Accumulation of amyloid-beta (Aβ), which is associated with Alzheimer's disease, can be caused by excess production or insufficient clearance. Because of its β-sheet structure, fibrillar Aβ is resistant to proteolysis, which would contribute to slow degradation of Aβ plaques in vivo. Fibrillar Aβ can be internalized b...
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.1719808115
更新日期:2018-02-13 00:00:00
abstract::Two regions of human thyrotropin (thyroid-stimulating hormone, TSH) receptor (TSHR) (residues 12-44 and 308-364) were selected on the basis that they exhibit no sequence resemblance to luteinizing hormone/chorionic gonadotropin receptor. Five synthetic overlapping peptides (12-30, 24-44, 308-328, 324-344, and 339-364)...
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.88.9.3613
更新日期:1991-05-01 00:00:00
abstract::Metallic nanoscale structures are capable of supporting surface plasmon polaritons (SPPs), propagating collective electron oscillations with tight spatial confinement at the metal surface. SPPs represent one of the most promising structures to beat the diffraction limit imposed by conventional dielectric optics. Ag 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.0902064106
更新日期:2009-12-15 00:00:00