Abstract:
:Filipin, digitonin, and saponin react with membrane cholesterol to produce unique membrane alterations (sterol-specific complexes) that are easily discernible in freeze-fracture replicas. We have treated both noninnervated and innervated Xenopus embryonic muscle cells in culture with these agents. Freeze-fracture of these treated muscle cells showed that most areas of the muscle plasma membrane contain sterol-specific complexes (19- to 40-nm protuberances and dimples with filipin, a scalloped appearance with digitonin, or an irregular, rough appearance with saponin). However, these complexes were virtually absent from membrane areas of junctional and nonjunctional aggregates of acetylcholine receptor particles. This result suggests that the membrane matrix of these aggregates is low in cholesterol and that this membrane lipid heterogeneity may be linked to the mechanisms involved in their formation and stabilization on muscle cells in culture.
journal_name
Proc Natl Acad Sci U S Aauthors
Bridgman PC,Nakajima Ydoi
10.1073/pnas.78.2.1278subject
Has Abstractpub_date
1981-02-01 00:00:00pages
1278-82issue
2eissn
0027-8424issn
1091-6490journal_volume
78pub_type
杂志文章abstract::The mouse p19Arf (human p14ARF) tumor suppressor protein, encoded in part from an alternative reading frame of the Ink4a (Cdkn2a) gene, inhibits the Mdm2 E3 ubiquitin ligase to activate p53. Arf is not expressed in most normal tissues of young mice but is induced by high thresholds of aberrant hyperproliferative signa...
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.1707292114
更新日期:2017-07-11 00:00:00
abstract::We have investigated whether the large (5- to 15-fold) stimulation of synthesis of growth hormone (somatotropin) observed upon exposure of a strain of rat pituitary (GH3) cells to dexamethasone (a synthetic glucocorticoid) arises from a stimulation of pregrowth hormone mRNA. A good agreement was observed between the s...
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.74.6.2357
更新日期:1977-06-01 00:00:00
abstract::Go is a specific class ("other") of signal-transducing heterotrimeric GTP-binding proteins (G proteins) that is expressed in high levels in mammalian brain. We have cloned two different rat cDNAs encoding the alpha subunit of Go (Go alpha-1 and Go alpha-2) and a human Go alpha chromosomal gene. The human Go alpha gene...
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.88.8.2974
更新日期:1991-04-15 00:00:00
abstract::Data are presented that demonstrate that a dose of 10 R of x-rays to mature oocytes in Drosophila causes a significant increase, more than double the spontaneous frequency, of inherited translocations. The dose-frequency relationship appears to fit best a linear response between 10 and 50 R. From 50 to 500 R, the freq...
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.68.6.1095
更新日期:1971-06-01 00:00:00
abstract::This presentation reviews Chandra's major contribution to the understanding of nearby galaxies. After a brief summary on significant advances in characterizing various types of discrete x-ray sources, the presentation focuses on the global hot gas in and around galaxies, especially normal ones like our own. The hot ga...
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.0914255107
更新日期:2010-04-20 00:00:00
abstract::The complexity and specificity of metazoan transcription are determined by combinatorial control of the composition and activity of regulatory complexes. To investigate the basis of this specificity, we focused on the glucocorticoid receptor (GR), a single regulatory factor that integrates multiple signals to give ris...
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.1216108110
更新日期:2013-01-29 00:00:00
abstract::Release of formylmethionine from the reticulocyte ribosomal substrate, f[(3)H]Met-tRNA.ribosome, is promoted by reticulocyte release factor (RF). The initial rate of this reaction is stimulated by GTP but inhibited by GDPCP. Formation of an RF.UA[(3)H]A(2).ribosome complex is a measure of the binding of reticulocyte 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.70.8.2350
更新日期:1973-08-01 00:00:00
abstract::The transformation of human cells was examined by transfection of cloned oncogenic DNAs derived from the tumor virus simian virus 40 and from the human bladder carcinoma cell line EJ into diploid fibroblasts derived from foreskin (FS-2 cells). The simian virus 40 DNA was found to induce a morphologically transformed 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.80.24.7601
更新日期:1983-12-01 00:00:00
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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.181219298
更新日期:2001-08-28 00:00:00
abstract::Nanobacteria-like objects evidenced at the surface of the orthopyroxenes of the Tataouine meteorite in South Tunisia have been studied by scanning and transmission electron microscopies. A method of micromanipulation has been developed to ensure that exactly the same objects were studied by both methods. We have shown...
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.0832464100
更新日期:2003-06-24 00:00:00
abstract::Human Bestrophin 1 (hBest1) is a calcium-activated chloride channel that regulates neuronal excitability, synaptic activity, and retinal homeostasis. Mutations in hBest1 cause the autosomal-dominant Best macular dystrophy (BMD). Because hBest1 mutations cause BMD, but a knockout does not, we wondered if hBest1 mutants...
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.1400248111
更新日期:2014-04-29 00:00:00
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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.1232294100
更新日期:2003-06-10 00:00:00
abstract::A change in the conformation of the active site of scallop myosin under the influence of regulatory amounts of Ca2+ has been identified by use of the ADP photoaffinity analog 2-[(4-azido-2-nitrophenyl)amino]ethyl diphosphate (NANDP). NANDP, trapped at the active site with Mn2+ and vanadate, photolabeled preferentially...
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.90.1.35
更新日期:1993-01-01 00:00:00
abstract::Two-component signal transduction systems are most often found in prokaryotic organisms where they are responsible for mediating the cellular responses to many environmental stimuli. These systems are composed of an autophosphorylating histidine kinase and a response regulator. We have found evidence for the existence...
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.93.8.3416
更新日期:1996-04-16 00:00:00
abstract::The envelope spike of HIV is one of the most highly N-glycosylated structures found in nature. However, despite extensive research revealing essential functional roles in infection and immune evasion, the chemical structures of the glycans on the native viral envelope glycoprotein gp120--as opposed to recombinantly ge...
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.1006498107
更新日期:2010-08-03 00:00:00
abstract::The aspartate receptor involved in chemotaxis is modified by methyl esterification at four distinct glutamate residues during the adaptive response of this receptor. To explain the high degree of specificity of this modification, it has been proposed that the methyltransferase recognizes the sequence Glu-Glu-Xaa-Xaa-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.83.18.6707
更新日期:1986-09-01 00:00:00
abstract::Immune responses to several soluble antigens were compared between B6.C-H-2bm12 mutant and wild-type B6 mice by using a lymph node T-cell proliferation assay. B6.C-H-2bm12 mice failed to respond to beef insulin whereas other IA gene-controlled responses, such as response to poly(L-Tyr, L-Glu)--poly(DL-Ala, L-Lys) and ...
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.78.10.6406
更新日期:1981-10-01 00:00:00
abstract::Regulated proteolysis is required to execute many cellular programs. In Caulobacter crescentus, timely degradation of the master regulator CtrA by ClpXP protease is essential for cell-cycle progression and requires the colocalization of CtrA and RcdA. Here, we establish a biochemical framework to understand regulated ...
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.0701776104
更新日期:2007-04-17 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1969-08-01 00:00:00
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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.1511585112
更新日期:2015-09-15 00:00:00
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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.0506483102
更新日期:2005-12-13 00:00:00
abstract::A dynamical theory for the evolution of the genetic code is presented, which accounts for its universality and optimality. The central concept is that a variety of collective, but non-Darwinian, mechanisms likely to be present in early communal life generically lead to refinement and selection of innovation-sharing 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.0603780103
更新日期:2006-07-11 00:00:00
abstract::To identify the binding domain for dihydropyridine Ca2+ antagonists, skeletal muscle Ca2+ channels were photolabeled with [3H](+)-PN200-110 and [3H]azidopine. Regions of alpha 1 photolabeled by these ligands were then identified by antibody mapping of proteolytic fragments. Approximately 50% of the specific labeling 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.88.23.10769
更新日期:1991-12-01 00:00:00
abstract::Leptin acts as a potent inhibitory factor against obesity by regulating energy expenditure, food intake, and adiposity. The obese diabetic db/db mouse, which has defects in leptin receptor, displays enhanced neural responses and elevated behavioral preference to sweet stimuli. Here, we show the effects of leptin on 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.190066697
更新日期:2000-09-26 00:00:00
abstract::The effect of combining hormonal treatment consisting of long-acting microcapsules of the agonist [D-Trp6]LH-RH (the D-tryptophan-6 analog of luteinizing hormone-releasing hormone) with the chemotherapeutic agent cyclophosphamide was investigated in the Dunning R-3327H rat prostate cancer model. Microcapsules of [D-Tr...
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.82.8.2498
更新日期:1985-04-01 00:00:00
abstract::Heparin is the most widely prescribed biopharmaceutical in production globally. Its potent anticoagulant activity and safety makes it the drug of choice for preventing deep vein thrombosis and pulmonary embolism. In 2008, adulterated material was introduced into the heparin supply chain, resulting in several hundred 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.1920880117
更新日期:2020-04-28 00:00:00
abstract::CR1 is a short interspersed repetitive DNA element originally identified in the domestic chicken (Gallus gallus). However, unlike virtually all other such sequences described to date, CR1 is not confined to one or a few closely related species. It is probably a ubiquitous component of the avian genome, having been det...
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.88.13.5814
更新日期:1991-07-01 00:00:00
abstract::An in-depth knowledge of the interaction of water with amorphous silica is critical to fundamental studies of interfacial hydration water, as well as to industrial processes such as catalysis, nanofabrication, and chromatography. Silica has a tunable surface comprising hydrophilic silanol groups and moderately hydroph...
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.1722263115
更新日期:2018-03-20 00:00:00
abstract::The foundation of marine coral reef ecosystems is calcium carbonate accumulated primarily by the action of hard corals (Coelenterata: Anthozoa: Scleractinia). Colonial hard coral polyps cover the surface of the reef and deposit calcium carbonate as the aragonite polymorph, stabilized into a continuous calcareous skele...
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.211439698
更新日期:2001-10-09 00:00:00
abstract::Hyperphosphorylated α-synuclein in Lewy bodies and Lewy neurites is a characteristic neuropathological feature of Parkinson's disease (PD) and Dementia with Lewy bodies (DLB). The catalytic subunit of the specific phosphatase, protein phosphatase 2A (PP2A) that dephosphorylates α-synuclein, is hypomethylated in these ...
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.1813365115
更新日期:2018-12-18 00:00:00