Role of Chromatin in HIV Transcriptional Regulation

染色质在 HIV 转录调控中的作用

• 批准号: 7284556
• 负责人: Eric M. Verdin
• 金额: $ 40.95万
• 依托单位: J. DAVID GLADSTONE INSTITUTES
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-05-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7284556
• 关键词: Acetylation; Agreement; Binding; Biological Assay; Chromatin; Chromatin Remodeling Factor; Complex; Deoxyribonuclease I; EP300 gene; Event; Future; Genetic Transcription; Genome; Goals; HIV; Histones; Interleukin-4; Mediating; Nucleosomes; PCAF gene; Play; Positioning Attribute; Proteins; Publishing; RNA Interference; Reaction; Recruitment Activity; Regulation; Repression; Role; SMARCA4 gene; Site; Soluble Baker' s Antifol; System; Testing; Transactivation; Transcription Coactivator; Transcription Initiation Site; Transcription Regulatory Protein; Transcriptional Activation; Transcriptional Regulation; Work; chromatin immunoprecipitation; cofactor; derepression; gene repression; hSWI/SNF; in vivo; novel; polybromo; promoter; research study; tat Protein; transcription factor

DESCRIPTION (provided by applicant): The long term goal of this proposal is to understand the mechanism of HIVtranscriptional regulation in the context of chromatin. We have previously shown that the integrated HIV promoter is organized in an array of precisely positioned nucleosomes and two nucleosome-free regions where transcription factors bind. A single nucleosome (nuc-1), is positioned after the transcription start site and is disrupted during transcriptional activation of the HIV promoter by Tat. We have recently identified the human SWI/SNF complex as critical for nuc-1 remodeling. We propose to further study the ordered recruitment of distinct cofactors that are necessary for Tat-mediated transactivation of the HIV promoter. Our specific aims are to: 1. To characterize the role and the mechanism of action of the huSWI/SNF chromatin remodeling complex called PBAF in nuc-1 remodeling and in HIV transcriptional activation by Tat. 2. Aim 2. To characterize the role of the BAF chromatin remodeling complex in HIV transcriptional repression. We have recently demonstrated that knockdown of specific subunits of the BAF complex are associated with transcriptional derepression of the HIV promoter. We plan to expand these observations and to study how the Tat protein mediates the switch between the BAF and PBAF complexes during HIV transcriptional activation. 3. To study the order of recruitment of transcriptional regulatory proteins to the HIV promoter in vivo. We have demonstrated that the chromatin regulators p300, huSWI/SNF, and PCAF participate to the transcriptional regulation of HIV transcription in the context of chromatin. We propose to use chromatin immunoprecipitation assays and RNA interference to study the order of recruitment of these factors along with the pTEFb complex, to the HIV promoter. We will test the hypothesis that Tat acetylation plays a coordinating role in the ordered recruitment of these factors to the HIV promoter. We anticipate that these experiments will further our understanding of HIV transcription integrated into chromatin. These experiments have the potential of identifying novel factors mediating HIV transcriptional regulation that could be targeted therapeutically in the future.

描述（由申请人提供）：本提案的长期目标是了解染色质背景下HIV转录调控的机制。我们以前已经表明，整合的HIV启动子是组织在一个阵列的精确定位的核小体和两个核小体的转录因子结合的区域。单个核小体（nuc-1）位于转录起始位点之后，并且在HIV启动子的转录激活过程中被达特破坏。我们最近发现人SWI/SNF复合物对nuc-1重塑至关重要。我们建议进一步研究Tat介导的HIV启动子反式激活所必需的不同辅因子的有序招募。我们的具体目标是：1.表征huSWI/SNF染色质重塑复合物（称为PBAF）在nuc-1重塑和达特HIV转录激活中的作用和作用机制。2.目标2.研究BAF染色质重塑复合物在HIV转录抑制中的作用。我们最近已经证明，敲低BAF复合物的特定亚基与HIV启动子的转录去抑制有关。我们计划扩大这些观察，并研究如何达特蛋白介导的BAF和PBAF复合物之间的开关在HIV转录激活。3.研究转录调节蛋白在体内向HIV启动子募集的顺序。我们已经证明，染色质调节因子p300，huSWI/SNF，和PCAF参与的转录调控的HIV转录的背景下，染色质。我们建议使用染色质免疫沉淀试验和RNA干扰来研究这些因子与pTEFb复合物一起沿着募集到HIV启动子的顺序。我们将测试的假设，达特乙酰化起着协调作用，这些因素的有序招聘的HIV启动子。我们预计，这些实验将进一步加深我们对HIV转录整合到染色质中的理解。这些实验有可能确定新的因素介导的艾滋病毒转录调控，可以在未来的治疗目标。