Abstract:
:Avian homologues of mammalian gamma delta and alpha beta T-cell antigen receptors, TCR1 and TCR2, have been identified with monoclonal antibodies. These TCR isotypes are associated with the avian CD3 proteins on the T-cell surface. During chick development, T-cell subpopulations bearing CD3/TCR1 or CD3/TCR2 receptor complexes are generated sequentially in the thymus and seeded to the periphery in the same order. In this study, we used two-color immunofluorescence to identify the subsequent development of a third subpopulation of T cells, provisionally named TCR3. These CD3+ cells, which expressed neither TCR1 nor TCR2, were first detected in the blood 1 week after hatching and increased numerically as a function of age to account for approximately 15% of the circulating T-cell pool in adults. Most (greater than 80%) of the TCR3 cells expressed the CD4 accessory molecule. The relative incidence of the TCR3 subpopulation increased dramatically as a consequence of embryonic treatment with anti-TCR2 antibody and thymectomy after hatching. Two disulfide-linked polypeptides, of Mr 48,000 and 40,000, were associated with the CD3 complex on the TCR3 cells. Examination of the TCR protein backbones and peptide mapping of the TCR chains after partial proteolysis indicated that the TCR3 heterodimer differs from both TCR1 and TCR2. These results suggest the existence of a third class of T-cell receptors in birds.
journal_name
Proc Natl Acad Sci U S Aauthors
Chen CH,Sowder JT,Lahti JM,Cihak J,Lösch U,Cooper MDdoi
10.1073/pnas.86.7.2351subject
Has Abstractpub_date
1989-04-01 00:00:00pages
2351-5issue
7eissn
0027-8424issn
1091-6490journal_volume
86pub_type
杂志文章abstract::We used 5,6-dichloro-beta D-ribofuranosyl-benzimidazole (DRB), a selective and reversible inhibitor of mRNA production, to investigate the regulation of the pathway leading to resistance to viruses in cells treated with interferon (IF). DRB allows initiation of transcription but promotes premature termination of 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.77.1.452
更新日期:1980-01-01 00:00:00
abstract::Populations of isogenic embryonic stem cells or clonal bacteria often exhibit extensive phenotypic heterogeneity that arises from intrinsic stochastic dynamics of cells. The phenotypic state of a cell can be transmitted epigenetically in cell division, leading to correlations in the states of cells related by descent....
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.1504407112
更新日期:2015-05-05 00:00:00
abstract::Gyrate atrophy of the choroid and retina (GA) is an inherited chorioretinal degeneration caused by deficiency of ornithine delta-aminotransferase (OAT; L-ornithine: 2-oxo-acid aminotransferase; EC 2.6.1.13). GA is one of the "Finnish genetic diseases," a group of several rare monogenic disorders that occur with increa...
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.86.1.197
更新日期:1989-01-01 00:00:00
abstract::The nuclear receptor REV-ERBα integrates the circadian clock with hepatic glucose and lipid metabolism by nucleating transcriptional comodulators at genomic regulatory regions. An interactomic approach identified O-GlcNAc transferase (OGT) as a REV-ERBα-interacting protein. By shielding cytoplasmic OGT from proteasoma...
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.1805397115
更新日期:2018-11-20 00:00:00
abstract::The DNA-binding domain of c-Myb consists of three homologous tandem repeats of 52 amino acids. The structure of the third (C-terminal) repeat obtained by NMR analysis has a conformation related to the helix-turn-helix motif. To identify the role of each repeat in the sequence recognition of DNA, we analyzed specific 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.90.20.9320
更新日期:1993-10-15 00:00:00
abstract::Retinoblastoma-related (RBR) proteins regulate cell division in higher eukaryotes by controlling the adenovirus E2 promoter binding factor (E2F)/dimerization partner (DP) family of transcription factors that regulate expression of many genes involved in cell-cycle progression. We identified a previously undescribed me...
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.0506160102
更新日期:2005-09-13 00:00:00
abstract::In characterizing mice with targeted disruption of the SerpinB2 gene, we observed animals that were small at birth with delayed growth and decreased life expectancy. Although this phenotype cosegregated with homozygosity for the inactive SerpinB2 allele, analysis of homozygous SerpinB2-deficient mice derived from two ...
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.1012050107
更新日期:2010-09-28 00:00:00
abstract::The specificity of human skin collagenase and of an enzyme from an invasive tumor were studied by using types I, II, III, IV, and V (AB) collagen as substrates. Human skin collagenase degraded types I, II, and III collagen, producing the characteristic 3/4 and 1/4 cleavage products, but failed to degrade type IV or V ...
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.76.5.2268
更新日期:1979-05-01 00:00:00
abstract::Global climate change is expected to have broad ecological consequences for species and communities. Attempts to forecast these consequences usually assume that changes in air or water temperature will translate into equivalent changes in a species' organismal body temperature. This simple change is unlikely because 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.0510992103
更新日期:2006-06-20 00:00:00
abstract::To determine whether the human pituitary contains a previously unidentified, nonprolactin (non-hPRL), non-growth-hormone (non-hGH) factor capable of stimulating mammary development, we tested the effects of whole human pituitary extract (hPE) and pituitary extracts depleted of hPRL and hGH ("stripped hPE") in hypophys...
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.84.22.8110
更新日期:1987-11-01 00:00:00
abstract::NGC 7027 shows the richest spectrum of any known gaseous nebula. In the region of the spectrum surveyed we have measured lines of ions of H, He, C, N, O, F, Ne, Mg, Si, P, S, Cl, Ar, K, Ca, Mn, and Fe using the new Hamilton Echelle Spectrograph of Lick Observatory with a charge-coupled device (CCD) detector. Since a 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.85.8.2417
更新日期:1988-04-01 00:00:00
abstract::Several dual route models of human speech processing have been proposed suggesting a large-scale anatomical division between cortical regions that support motor-phonological aspects vs. lexical-semantic aspects of speech processing. However, to date, there is no complete agreement on what areas subserve each route or ...
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.1614038114
更新日期:2016-12-27 00:00:00
abstract::Mobile ectothermic animals can control their body temperatures by selecting specific thermal conditions in the environment, but embryos--trapped within an immobile egg and lacking locomotor structures--have been assumed to lack that ability. Falsifying that assumption, our experimental studies show that even early sta...
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.1102965108
更新日期:2011-06-07 00:00:00
abstract::Studies of biotic remains of polar ice caps have been limited to morphological identification of plant pollen and spores. By using sensitive molecular techniques, we now demonstrate a much greater range of detectable organisms; from 2000- and 4000-year-old ice-core samples, we obtained and characterized 120 clones tha...
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.96.14.8017
更新日期:1999-07-06 00:00:00
abstract::Treatment of a human breast cancer cell line (MDA-MB-435) in nude mice with a recombinant adenovirus containing the human interferon (IFN) consensus gene, IFN-con1 (ad5/IFN), resulted in tumor regression in 100% of the animals. Tumor regression occurred when virus was injected either within 24 hr of tumor cell implant...
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.93.9.4513
更新日期:1996-04-30 00:00:00
abstract::The type specimen for Australopithecus africanus (Taung) includes a natural endocast that reproduces most of the external morphology of the right cerebral hemisphere and a fragment of fossilized face that articulates with the endocast. Despite the fact that Taung died between 3 and 4 y of age, the endocast reproduces ...
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.1119752109
更新日期:2012-05-29 00:00:00
abstract::Transcription in eukaryotic nuclei is carried out by DNA-dependent RNA polymerases I, II, and III. Human RNA polymerase III (Pol III) transcribes small untranslated RNAs that include tRNAs, 5S RNA, U6 RNA, and some microRNAs. Increased Pol III transcription has been reported to accompany or cause cell transformation. ...
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.0914980107
更新日期:2010-03-02 00:00:00
abstract::Helodermin is a vasoactive intestinal peptide-like peptide in the salivary gland venom of the lizard Heloderma suspectum. Helodermin-like immunofluorescence was observed in the parafollicular (C) cells in several mammals and in the C cell homologues of the chicken ultimobranchial gland. Thus, helodermin-like peptides ...
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.86.4.1357
更新日期:1989-02-01 00:00:00
abstract::To explore the basis for the template specificities of the bacteriophage T3 and T7 RNA polymerases (EC 2.7.7.6), we determined the nucleotide sequences of six promoters recognized by the T3 RNA polymerase and compared them with the previously determined promoter sequences recognized by the bacteriophage T7 RNA polymer...
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.80.10.2814
更新日期:1983-05-01 00:00:00
abstract::Meiotic recombination in the yeast Saccharomyces cerevisiae is initiated by programmed double-strand breaks at selected sites throughout the genome (hotspots). alpha-Hotspots are binding sites for transcription factors. Double-strand breaks at alpha-hotspots require binding of transcription factor but not high levels ...
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.201529598
更新日期:2001-12-04 00:00:00
abstract::The P23T mutant of human gammaD-crystallin (HGD) is associated with cataract. We have previously investigated the solution properties of this mutant, as well as those of the closely related P23V and P23S mutants, and shown that although mutations at site 23 of HGD do not produce a significant structural change in 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.0707412104
更新日期:2007-10-23 00:00:00
abstract::The inability to perceive and coordinate both internal and external signals that function to regulate cellular growth and proliferation is a hallmark of oncogenic transformation. To examine the effects of the v-mos oncogene on distinct signal transduction pathways, the 6m2 cell line was used, in which expression of 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.86.2.597
更新日期:1989-01-01 00:00:00
abstract::Biological organisms have evolved a wide range of immune mechanisms to defend themselves against pathogens. Beyond molecular details, these mechanisms differ in how protection is acquired, processed, and passed on to subsequent generations-differences that may be essential to long-term survival. Here, we introduce a 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.1600663113
更新日期:2016-08-02 00:00:00
abstract::The major late transcriptional unit of adenovirus type 2 has served as a model for studying transcription in eukaryotes. We report that pausing and premature termination are intrinsic to the transcription of this transcriptional unit by RNA polymerase II. In vivo and in isolated nuclei, transcription pauses at discret...
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.81.19.5931
更新日期:1984-10-01 00:00:00
abstract::Site-directed spin labeling EPR (SDSL-EPR) was used to determine the structure of the inhibitory region of TnI in the intact cardiac troponin ternary complex. Maeda and collaborators have modeled the inhibitory region of TnI (skeletal 96-112: the structural motif that communicates the Ca(2+) signal to actin) as a kink...
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.202477399
更新日期:2002-10-01 00:00:00
abstract::Two subjects, of 11,000 healthy individuals screened, were found to be missing three and four immunoglobulin isotypes, respectively (IgA1, IgG2, and IgG4; IgA1, IgG2, IgG4, and IgE), and have been analyzed at the DNA level by means of Southern blotting and Ig heavy-chain-specific probes. A broad deletion within the he...
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.81.18.5811
更新日期:1984-09-01 00:00:00
abstract::We have isolated a cDNA clone, called Dmyd for Drosophila myogenic-determination gene, that encodes a protein with structural and functional characteristics similar to the members of the vertebrate MyoD family. Dmyd clone encodes a polypeptide of 332 amino acids with 82% identity to MyoD in the 41 amino acids of the 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.88.9.3782
更新日期:1991-05-01 00:00:00
abstract::Pathologic ocular neovascularization commonly causes blindness. It is critical to identify the factors altered in pathologically proliferating versus normally quiescent vessels to develop effective targeted therapeutics. MicroRNAs regulate both physiological and pathological angiogenesis through modulating expression ...
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.1508426112
更新日期:2015-09-29 00:00:00
abstract::Renal excretion of water and major electrolytes exhibits a significant circadian rhythm. This functional periodicity is believed to result, at least in part, from circadian changes in secretion/reabsorption capacities of the distal nephron and collecting ducts. Here, we studied the molecular mechanisms underlying circ...
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.0904890106
更新日期:2009-09-22 00:00:00
abstract::Ultraviolet (UV)-stimulated nonconservative DNA synthesis has been observed in E. coli rendered permeable to nucleoside triphosphates by exposure to toluene. This synthesis is detected in toluenized cells in which the background of UV-independent DNA synthesis is reduced by use of dnaB mutants temperature-sensitive fo...
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.70.1.129
更新日期:1973-01-01 00:00:00