Abstract:
:We have isolated and sequenced cDNA clones corresponding to the DR beta 1 and DR beta 2 loci from two homozygous B-cell lines typed as DR7 (Burkhart) and DR9 (ISK). These nucleotide sequences were compared to beta 1 and beta 2 chains of other DR haplotypes. The first-domain sequences of beta 2 chains are identical in DR4 and DR7 haplotypes. In addition, there is strong sequence homology within the 3' untranslated regions of beta 1 genes from DR4, -7, and -9 haplotypes, thus confirming the close evolutionary relationship among these three haplotypes. In contrast, the first-domain sequences of beta 1 molecules from these haplotypes are very different from each other and do not reflect the DR4, -7, -9 family relationship. Two explanations for the differences in degree of diversity between beta 1 and beta 2 chains are suggested. The differences may be a consequence of selection pressures; this implies functional differences for products of the beta 1 and beta 2 loci. Alternatively, closely linked segments of the human class II region may differ in their underlying rates of variation, independent of selection pressures, and this may in part account for the extraordinary diversity found in the beta 1 first domain.
journal_name
Proc Natl Acad Sci U S Aauthors
Gregersen PK,Moriuchi T,Karr RW,Obata F,Moriuchi J,Maccari J,Goldberg D,Winchester RJ,Silver Jdoi
10.1073/pnas.83.23.9149subject
Has Abstractpub_date
1986-12-01 00:00:00pages
9149-53issue
23eissn
0027-8424issn
1091-6490journal_volume
83pub_type
杂志文章abstract::We construct counterexamples to classical calculus facts such as the inverse and implicit function theorems in scale calculus-a generalization of multivariable calculus to infinite-dimensional vector spaces, in which the reparameterization maps relevant to symplectic geometry are smooth. Scale calculus is a corner sto...
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.1811701116
更新日期:2019-04-30 00:00:00
abstract::As the most prototypical G protein-coupled receptor, beta-adrenergic receptor (betaAR) regulates the pace and strength of heart beating by enhancing and synchronizing L-type channel (LCC) Ca(2+) influx, which in turn elicits greater sarcoplasmic reticulum (SR) Ca(2+) release flux via ryanodine receptors (RyRs). Howeve...
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.0906560106
更新日期:2009-10-20 00:00:00
abstract::Despite a growing number of ion channel genes implicated in hereditary ataxia, it remains unclear how ion channel mutations lead to loss-of-function or death of cerebellar neurons. Mutations in the gene KCNMA1, encoding the α-subunit of the BK channel have emerged as responsible for a variety of neurological phenotype...
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.1920008117
更新日期:2020-03-17 00:00:00
abstract::The MAL6 locus is one of five closely related unlinked loci, any one of which is sufficient for fermentation of maltose in Saccharomyces. Previous genetic analysis indicated that this locus is defined by two complementation groups, MALp and MALg. MALp reportedly is a regulatory gene required for inducible synthesis 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.81.9.2811
更新日期:1984-05-01 00:00:00
abstract::Many important hominid-bearing fossil localities in East Africa are in regions that are extremely hot and dry. Although humans are well adapted to such conditions, it has been inferred that East African environments were cooler or more wooded during the Pliocene and Pleistocene when this region was a central stage 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.1001824107
更新日期:2010-06-22 00:00:00
abstract::The fractionation of cells of a parsley suspension culture [Petroselinum crispum (Mill.) A. Hill] by protoplasting and subsequent removal of the vacuoles led to physiologically intact evacuolated protoplasts retaining light inducibility of chalcone synthase expression. Lysis of the evacuolated protoplasts permitted 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.91.11.5038
更新日期:1994-05-24 00:00:00
abstract::The constant heavy chain (CH1) domain affects antibody affinity and fine specificity, challenging the paradigm that only variable regions contribute to antigen binding. To investigate the role of the CH1 domain, we constructed IgA2 from the broadly neutralizing anti-HIV-1 2F5 IgG1, and compared 2F5 IgA2 and IgG bindin...
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.1200024109
更新日期:2012-07-31 00:00:00
abstract::Homologous recombination is an important biological process that occurs in all organisms and facilitates genome rearrangements and repair of DNA double-strand breaks. Eukaryotic Rad51 proteins (Rad51sp or Rhp51 in fission yeast) are functional and structural homologs of bacterial RecA protein, an evolutionarily conser...
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.2632890100
更新日期:2003-12-23 00:00:00
abstract::This investigation was undertaken to determine the possible role of growth hormone (GH) in the hormonal regulation of hepatic low density lipoprotein (LDL) receptor expression. Treatment of normal rats with estrogen (ethynylestradiol, 5 mg/kg per day) increased the number of hepatic LDL receptors, and the LDL receptor...
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.89.15.6983
更新日期:1992-08-01 00:00:00
abstract::Loss of function of CDKN2A/B, also known as INK4/ARF [encoding p16INK4A, p15INK4B, and p14ARF (mouse p19Arf)], confers susceptibility to cancers, whereas its up-regulation during organismal aging provokes cellular senescence and tissue degenerative disorders. To better understand the transcriptional regulation of p16 ...
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.1909720116
更新日期:2019-12-09 00:00:00
abstract::The internal dynamics of bacteriorhodopsin, the light-driven proton pump in the purple membrane of Halobacterium halobium, has been studied by inelastic neutron scattering for various conditions of temperature and hydration. Light activation can take place when the membrane is vibrating harmonically. The ability 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.90.20.9668
更新日期:1993-10-15 00:00:00
abstract::Restricted fetal growth is associated with postnatal mortality and morbidity and may be directly related to alterations in the capacity of the placenta to supply nutrients. We proposed previously that imprinted genes can regulate nutrient supply by the placenta. Here, we tested the hypothesis that the insulin-like gro...
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.0402508101
更新日期:2004-05-25 00:00:00
abstract::Spontaneous reciprocal mitotic recombination in the yeast Saccharomyces cerevisiae, associated with heteroallelic recombination, occurs almost exclusively at the two-strand stage and involves recombination of unduplicated chromosomes (i.e., during G1) or the unduplicated regions of chromosomes during the S phase of mi...
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.75.9.4436
更新日期:1978-09-01 00:00:00
abstract::The coordinated redistribution of sugars from mature "source" leaves to developing "sink" leaves requires tight regulation of sugar transport between cells via plasmodesmata (PD). Although fundamental to plant physiology, the mechanisms that control PD transport and thereby support development of new leaves have remai...
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.1919196117
更新日期:2020-03-03 00:00:00
abstract::We describe an algorithm to compute trisections of orientable four-manifolds using arbitrary triangulations as input. This results in explicit complexity bounds for the trisection genus of a 4-manifold in terms of the number of pentachora (4-simplices) in a triangulation. ...
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.1717173115
更新日期:2018-10-23 00:00:00
abstract::Global agricultural emissions of the greenhouse gas nitrous oxide (N2O) have increased by around 20% over the last 100 y, but regulation of these emissions and their impact on bacterial cellular metabolism are poorly understood. Denitrifying bacteria convert nitrate in soils to inert di-nitrogen gas (N2) via N2O and 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.1314529110
更新日期:2013-12-03 00:00:00
abstract::Systemic lupus erythematosus (SLE) is a multigenic autoimmune disease, and the major histocompatibility complex (MHC) class II polymorphism serves as a key genetic element. In SLE-prone (NZB x NZW)F(1) mice, the MHC H-2(d/z) heterozygosity (H-2(d) of NZB and H-2(z) of NZW) has a strong impact on disease; thus, congeni...
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.0405807101
更新日期:2004-09-21 00:00:00
abstract::Viperin is an IFN-inducible radical S-adenosylmethionine (SAM) enzyme that inhibits viral replication. We determined crystal structures of an anaerobically prepared fragment of mouse viperin (residues 45-362) complexed with S-adenosylhomocysteine (SAH) or 5'-deoxyadenosine (5'-dAdo) and l-methionine (l-Met). Viperin 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.1705402114
更新日期:2017-06-27 00:00:00
abstract::Interleukin 3 (IL-3) stimulates the proliferation and differentiation of various haematopoietic progenitor cells. Recently, IL-3 and other cytokines were reported to exert a neurotrophic activity and to be associated with neurological disorders, suggesting their complex role in the central nervous system. We now show ...
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.95.19.11354
更新日期:1998-09-15 00:00:00
abstract::There is evidence that interstitial telomere (TTAGGG)n-like sequences at chromosome 2 fragile sites play an important role in the somatic events that characterize the earliest phases of radiation-induced acute myeloid leukemia in the CBA/H mouse. Here we show that the highly inbred CBA/H colony unexpectedly contains f...
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.90.4.1407
更新日期:1993-02-15 00:00:00
abstract::Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is a hallmark of major depressive disorder. A number of studies have shown that this dysregulation is correlated with impaired forebrain glucocorticoid receptor (GR) function. To determine whether a primary, acquired deficit in forebrain GR signaling is 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.0406458102
更新日期:2005-01-11 00:00:00
abstract::Two mouse monoclonal anti-anti-idiotopic antibodies (anti-anti-Id, Ab3), AF14 and AF52, were prepared by immunizing BALB/c mice with rabbit polyclonal anti-idiotypic antibodies (anti-Id, Ab2) raised against antibody D1.3 (Ab1) specific for the antigen hen egg lysozyme. AF14 and AF52 react with an "internal image" mono...
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.94.16.8697
更新日期:1997-08-05 00:00:00
abstract::Many changes have been described in the brains of Alzheimer's disease (AD) patients, including loss of neurons and formation of senile plaques and neurofibrillary tangles. The molecular mechanisms underlying these pathologies are unclear. Northern blot, dot-blot, and reverse transcription-coupled PCR analyses have dem...
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.95.16.9620
更新日期:1998-08-04 00:00:00
abstract::The type VI secretion system (T6SS) is a lethal weapon used by many bacteria to kill eukaryotic predators or prokaryotic competitors. Killing by the T6SS results from repetitive delivery of toxic effectors. Despite their importance in dictating bacterial fitness, systematic prediction of T6SS effectors remains challen...
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.1505317112
更新日期:2015-07-21 00:00:00
abstract::Geckos can run rapidly on walls and ceilings, requiring high friction forces (on walls) and adhesion forces (on ceilings), with typical step intervals of approximately 20 ms. The rapid switching between gecko foot attachment and detachment is analyzed theoretically based on a tape model that incorporates the adhesion ...
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.0608841103
更新日期:2006-12-19 00:00:00
abstract::Natural antimicrobial peptides (AMPs) provide prototypes for the design of unconventional antimicrobial agents. Existing bulk assays measure AMP activity but do not provide details of the growth-halting mechanism. We use fluorescence microscopy to directly observe the attack of the human antimicrobial peptide LL-37 on...
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.1101130108
更新日期:2011-04-19 00:00:00
abstract::The poison frogs (family Dendrobatidae) are terrestrial anuran amphibians displaying a wide range of coloration and toxicity. These frogs generally have been considered to be aposematic, but relatively little research has been carried out to test the predictions of this hypothesis. Here we use a comparative approach 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.101134898
更新日期:2001-05-22 00:00:00
abstract::Hepatocytes polarize by forming functionally distinct sinusoidal (basolateral) and canalicular (apical) plasma membrane domains. Two distinct routes are used for delivery of membrane proteins to the canaliculus. Proteins having glycosylphosphatidylinositol anchors or single transmembrane domains are targeted to the si...
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.0503702102
更新日期:2005-10-18 00:00:00
abstract::In the retinae of many vertebrates, there are classes of horizontal cell that probably utilize gamma-aminobutyric acid (GABA) as a neurotransmitter. As with other amino acid transmitter agents, the postsynaptic action of GABA is thought to be terminated by uptake into neurons and glia surrounding the release site. 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.87.22.8945
更新日期:1990-11-01 00:00:00
abstract::Human activities have increased N availability dramatically in terrestrial and aquatic ecosystems. Extensive research demonstrates that local plant species diversity generally declines in response to nutrient enrichment, yet the mechanisms for this decline remain unclear. Based on an analysis of >900 species responses...
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.0408648102
更新日期:2005-03-22 00:00:00