Identification of a putative regulator of early T cell activation genes   总被引：98，自引：0，他引：98  

J P Shaw  P J Utz  D B Durand  J J Toole  E A Emmel  G R Crabtree 《Science (New York, N.Y.)》1988,241(4862):202-205

Molecules involved in the antigen receptor-dependent regulation of early T cell activation genes were investigated with the use of functional sequences of the T cell activation-specific enhancer of interleukin-2 (IL-2). One of these sequences forms a protein complex, NFAT-1, specifically with nuclear extracts of activated T cells. This complex appeared 10 to 25 minutes before the activation of the IL-2 gene. Studies with inhibitors of protein synthesis indicated that the time of synthesis of the activator of the IL-2 gene in Jurkat T cells corresponds to the time of appearance of NFAT-1. NFAT-1, or a very similar protein, bound functional sequences of the long terminal repeat (LTR) of the human immunodeficiency virus type 1; the LTR of this virus is known to be stimulated during early T cell activation. The binding site for this complex activated a linked promoter after transfection into antigen receptor-activated T cells but not other cell types. These characteristics suggest that NFAT-1 transmits signals initiated at the T cell antigen receptor.  相似文献   

Organic Glasses: A New Class of Photorefractive Materials     

PM Lundquist  R Wortmann  C Geletneky  RJ Twieg  M Jurich  VY Lee  CR Moylan  DM Burland 《Science (New York, N.Y.)》1996,274(5290):1182-1185

The performance of amorphous organic photorefractive (PR) materials in applications such as optical data storage is generally limited by the concentration of active molecules (chromophores) that can be incorporated into the host without forming a crystalline material with poor optical quality. In polymeric PR systems described previously, performance has been limited by the necessity of devoting a large fraction of the material to inert polymer and plasticizing components in order to ensure compositional stability. A new class of organic PR materials composed of multifunctional glass-forming organic chromophores is described that have long-term stability and greatly improved PR properties.  相似文献   

The Origin of the Great Bend of the Nile from SIR-C/X-SAR Imagery     

RJ Stern  MG Abdelsalam 《Science (New York, N.Y.)》1996,274(5293):1696-1698

The course of the Nile in northern Sudan follows a contorted path through Precambrian bedrock. Radar imagery shows that basement structures control the river's course in this region. Northward-flowing segments follow Precambrian fabrics, whereas east-west segments follow faults of much younger age. These faults may reflect recent uplift of the Nubian Swell and deflection of the river to the southwest to form the great bend of the Nile.  相似文献   

The global circulation of seasonal influenza A (H3N2) viruses     

Russell CA  Jones TC  Barr IG  Cox NJ  Garten RJ  Gregory V  Gust ID  Hampson AW  Hay AJ  Hurt AC  de Jong JC  Kelso A  Klimov AI  Kageyama T  Komadina N  Lapedes AS  Lin YP  Mosterin A  Obuchi M  Odagiri T  Osterhaus AD  Rimmelzwaan GF  Shaw MW  Skepner E  Stohr K  Tashiro M  Fouchier RA  Smith DJ 《Science (New York, N.Y.)》2008,320(5874):340-346

Antigenic and genetic analysis of the hemagglutinin of approximately 13,000 human influenza A (H3N2) viruses from six continents during 2002-2007 revealed that there was continuous circulation in east and Southeast Asia (E-SE Asia) via a region-wide network of temporally overlapping epidemics and that epidemics in the temperate regions were seeded from this network each year. Seed strains generally first reached Oceania, North America, and Europe, and later South America. This evidence suggests that once A (H3N2) viruses leave E-SE Asia, they are unlikely to contribute to long-term viral evolution. If the trends observed during this period are an accurate representation of overall patterns of spread, then the antigenic characteristics of A (H3N2) viruses outside E-SE Asia may be forecast each year based on surveillance within E-SE Asia, with consequent improvements to vaccine strain selection.  相似文献   

THE CARNEGIE FOUNDATION     

Gager CS  Daumford WI  Shaw HB 《Science (New York, N.Y.)》1910,31(803):780-781

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A TRIPLE-SPECTRUM DISCHARGE TUBE     

Shaw RW  Sabine GB 《Science (New York, N.Y.)》1931,74(1911):179-180

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ALCALIGENES ABORTUS FROM THE SPINAL FLUID     

Shaw FW 《Science (New York, N.Y.)》1929,70(1819):454-455

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Mechanism of Na+/H+ antiporting     

Arkin IT  Xu H  Jensen MØ  Arbely E  Bennett ER  Bowers KJ  Chow E  Dror RO  Eastwood MP  Flitman-Tene R  Gregersen BA  Klepeis JL  Kolossváry I  Shan Y  Shaw DE 《Science (New York, N.Y.)》2007,317(5839):799-803

Na+/H+ antiporters are central to cellular salt and pH homeostasis. The structure of Escherichia coli NhaA was recently determined, but its mechanisms of transport and pH regulation remain elusive. We performed molecular dynamics simulations of NhaA that, with existing experimental data, enabled us to propose an atomically detailed model of antiporter function. Three conserved aspartates are key to our proposed mechanism: Asp164 (D164) is the Na+-binding site, D163 controls the alternating accessibility of this binding site to the cytoplasm or periplasm, and D133 is crucial for pH regulation. Consistent with experimental stoichiometry, two protons are required to transport a single Na+ ion: D163 protonates to reveal the Na+-binding site to the periplasm, and subsequent protonation of D164 releases Na+. Additional mutagenesis experiments further validated the model.  相似文献   

COCCIDIOIDAL GRANULOMA     

Shaw FW 《Science (New York, N.Y.)》1931,73(1887):237

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AN IMPROVED METHOD FOR THE STUDY OF NUTRITIONAL ANEMIA IN THE WHITE RAT     

Nevens WB  Shaw DD 《Science (New York, N.Y.)》1930,72(1862):249-251

Experiments in our laboratory have demonstrated that white rats fed only fresh whole milk secured enough minerals from their cages to prevent anemia. Animals consuming large amounts of milk became anemic more quickly than those limited to small amounts. Access to feces delayed somewhat the onset of anemia. These results probably explain some of the conflicting data reported in the literature and also raise a question regarding the correctness of conclusions drawn from experiments in which recognition was not given the factors shown in this study to be important.  相似文献