TRANSCRIPTION ACTIVATION BY HIV, TAT, HTLV TAX & HBV PX

描述（来自研究者摘要）：这是一次竞争性更新 应用程序.上一笔拨款是用于研究 三种致病病毒的调节蛋白激活转录， 具体地，人免疫缺陷病毒1型（HIV-1）的达特蛋白， 人T细胞白血病病毒1型（HTLV-1）的Tax蛋白和pX B型肝炎病毒（HBV）的蛋白质。在本申请中，申请人寻求 更详细地了解这些病毒调节的作用机制， 蛋白质及其在病毒复制和人类疾病中的作用。的理由 因为这项提议主要依赖于两项相对较新的技术。一是 染色质免疫沉淀（ChIP）测定，其允许检测 在活细胞中与DNA物理相关的特定蛋白质。 第二，使用高密度DNA微阵列的全基因组表达分析， 这使得能够分析大量人类基因组的转录谱， 基因.具体目标是：（1）更详细地了解HIV-1达特 在体外和体内刺激转录。调查员已经确认 一个达特辅因子，Tat-SF 1，并已表明它是一个通用的转录 伸长因子第二个延伸因子AIEF也被牵涉其中， 仍有待确认。Tat-SF 1和AIEF及其达特激活机制 将进一步研究体内。(2)研究HTLV-1 Tax和HBV pX 调节细胞bZIP蛋白的DNA结合。调查显示， Tax和pX显著增加了DNA结合活性，并改变了 靶向选择性的各种细胞蛋白质，具有基本的 区域-亮氨酸拉链（bZIP）DNA结合结构域，通过促进 二聚化。实验被提议理解改变的DNA的基础 结合特异性，所涉及的细胞蛋白质，以及 DNA-蛋白质相互作用(3)分析HTLV-1 Tax和HBV pX如何激活 体内转录和转化细胞。为了测试不同的预测 这些蛋白质如何激活转录的模型， 参与激活的蛋白质，并识别激活的细胞基因 这可能会导致疾病。 (4)了解BEF的作用机制。调查员已经确认 bZIP所需的核蛋白BEF（bZIP增强因子） prtoein功能，与税务和pX协同工作。然而，BEF的工作原理是 一种不同的机制，作为分子伴侣。实验被提议为 进一步研究BEF的作用机制。

DESCRIPTION (from investigator's abstract): This is a competitive renewal application. The previous grant was for studying how the trancriptional regulatory proteins of three pathogenic viruses activate transcription, specifically, the Tat protein of human immunodeficiency virus type 1 (HIV-1), the Tax protein of human T-cell leukemia virus type 1 (HTLV-1), and the pX protein of hepatitis B virus (HBV). In this application, the applicant seeks to understand in greater detail the mechanism of action of these viral regulatory proteins and their role in viral replication and human disease. The rationale for the proposal relies heavily on two relatively new technologies. First, the chromatin immunoprecipitation (ChIP) assay, which allows for the detection of specific proteins that are physically associated with DNA in living cells. Second, the genome-wide expression analysis using high density DNA microarrays, which enables the analysis of transcription profiles of a large array of human genes. The specific aims are: (1) To understand in greater detail how HIV-1 Tat stimulates transcription in vitro and in vivo. The investigator has identified a Tat cofactor, Tat-SF1, and has shown that it is a general transcription elongation factor. A second elongation factor has been implicated, AIEF, and remains to be identified. Tat-SF1 and AIEF and the mechanisms of Tat activation in vivo will be investigated further. (2) To study how HTLV-1 Tax and HBV pX regulates DNA binding of cellular bZIP proteins. The investigator has shown that Tax and pX dramatically increase the DNA binding activity and alter the target selectivity of a wide variety of cellular proteins that possess a basic region-leucine zipper (bZIP) DNA binding domain, through promotion of dimerization. Experiments are proposed to undersstand the basis of altered DNA binding specificity, the cellular proteins involved, and details of the DNA-protein interactions. (3) To analyze how HTLV-1 Tax and HBV pX activate transcription in vivo and transform cells. To test the prediction of different models of how these proteins activate transcription, to identify cellular proteins involved in the activation, and to identify cellular genes activated that may contribute to disease. (4) To understand the mechanism of BEF action. The investigator has identified a nuclear protein BEF (for bZIP-enhancing factor) which is required for bZIP prtoein functions, work synergistically with Tax and pX. However, BEF works by a different mechanism, as a molecular chaperone. Experiments are proposed to further study the mechanism of BEF action.