Functional Map -- HIV Tat Second Exon in Cytokine Regulation

艾滋病毒和艾滋病感染是世界性的严重健康问题。尽管在发现艾滋病毒与艾滋病之间的关系方面取得了显著进展，并导致发达世界的治疗得到显著改善，但我们仍然远远没有达到可以在全世界实施的有效预防或治疗。因此，更好地了解病毒与宿主之间的致病关系仍然是科学的负担。确实有 一些HFV-1相关的病理，包括HIV-1相关的痴呆（HIVD），其不能很好地用病毒复制水平来解释，并且不能简单地通过有效控制复制而消失。HIV-1达特蛋白在病毒转录中的作用已得到充分研究，它是介导一系列HIV病理学（包括HIVD和卡波西肉瘤）的显著候选病毒组分。达特对这些非LTR活性的分子机制和氨基酸需求尚不清楚。此外，全长Tat 101蛋白相对于单外显子Tat 72形式而言研究不足，特别是其通过调节宿主基因表达在HIV-1发病机制中的作用。这项建议旨在填补这一空白。中心假设是在达特第二外显子内存在独特的、可定义的结构域，其在全长蛋白质的背景下负责宿主基因的完全调节。我们的具体目标将解决这一假设，通过定义细胞因子基因，以最明显的差异方式响应于目标1中的两种生理相关形式的达特（Tat 72和Tat 101）。这将在目标2中通过合理的靶向缺失诱变方法来跟踪，以粗略地定位第二外显子中的氨基酸区域，该区域为全长蛋白质提供在细胞因子基因调节中的附加功能。最后，在目标3中，通过引入逻辑设计的功能区， 单个氨基酸取代以测试对细胞因子基因调节的影响。在这项研究的结论，我们将有显着推进该领域的理解的第二外显子的达特完全介导宿主基因调控的分子要求。我们将处于一个有利的位置继续调查达特 有助于HFV-1的发病机制，因为我们将有一套独特的工具来探测与达特第二外显子内的功能元件接触的细胞蛋白伴侣。我们的长期目标是使用这些工具来研究达特蛋白在HIV-1相关病理学，特别是HIVD中的生物学作用和意义。

Infection with HIV and AIDS are devastating worldwide health problems. Although progress has been outstanding in discovering the relationship between HIV and AIDS and this has resulted in dramatically improved treatment in the developed world, we are still far from effective prevention or treatment that can be implemented worldwide. Thus the burden on science to better understand the pathogenic relationship between virus and host remains. Indeed, there are some HFV-1 associated pathologies, including HIV-1 associated dementia (HIVD), that simply are not well explained by the level of viral replication and may not disappear simply with effective control of replication. The HIV-1 Tat protein, well-studied for its role in viral transcription, represents a conspicuous candidate viral component that mediates a range of HIV pathologies, including HIVD and Kaposi's sarcoma. The molecular mechanisms and amino acid requirements of Tat for these non-LTR activities remain unclear. Further the full-length Tat101 protein has been understudied relative to the single exon Tat72 form, particularly for its role in HIV-1 pathogenesis through regulation of host gene expression. This proposal seeks to fill that gap. The central hypothesis is that there is a unique, definable domain within the Tat second exon, that in the context of the full length protein, is responsible for full regulation of host genes. Our specific aims will address this hypothesis by defining the cytokine genes that respond in the most clearly differential manner to the two physiologically relevant forms of Tat (Tat72 and Tat101) in aim 1. This will be followed up in aim 2 by a rationally targeted deletion mutagenesis approach to grossly map the amino acid region in the second exon that provides the added function to the full length protein in regulation of cytokine genes. Finally, in aim 3, the functional region identified by the deletion analysis will be fine mapped by introduction of logically designed individual amino acid substitutions to test the effect on cytokine gene regulation. At the conclusion of this study, we will have significantly advance the field in understanding the molecular requirements of the second exon of Tat to fully mediate host gene regulation. We will be in an opportune position to continue to investigate the pathways by which Tat contributes to HFV-1 pathogenesis because we will have a unique set of tools with which to probe the cellular protein partners that contact the functional element within the Tat second exon. It is our long range goal to use these tools to investigate the biological role and significance of the Tat protein on HIV-1 associated pathologies, particularly HIVD.