UNDERSTANDING THE MOLECULAR BASIS OF EPIGENETIC TRANSCRIPTIONAL SILENCING

了解表观遗传转录沉默的分子基础

• 批准号: 8360578
• 负责人: Yvonne Nsokika Fondufe-Mittendorf
• 金额: $ 18.38万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8360578
• 关键词: Alpha Cell; Binding; Cells; Centers of Research Excellence; Chromatin; Complex; Data; Development; Epigenetic Process; Equilibrium; Event; Freezing; Funding; Gene Expression Regulation; Gene Silencing; Genes; Grant; Growth; Histones; Homeostasis; Malignant Neoplasms; Measures; Molecular; National Center for Research Resources; Partner in relationship; Pattern; Polymerase Chain Reaction; Principal Investigator; Regulator Genes; Relative (related person); Research; Research Infrastructure; Resources; Source; Structure; System; Testing; Time; Transcription Factor TFIIB; United States National Institutes of Health; Yeasts; base; chromatin immunoprecipitation; cost; gene repression; human disease; promoter; transcription factor

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Epigenetic silencing, the heritable repression of transcription within chromatin domains, is critical in eukaryotic gene regulation. Maintaining homeostasis requires a delicate balance of gene regulatory events involving transcription factors. Deregulation of silencing patterns ushers growth of aberrant cells, and development and proliferation of cancer. However, the molecular mechanism of epigenetic silencing remains unknown. My previous data indicate that silencing is initiated downstream of activator binding but upstream of TFIIB recruitment and preinitiation-complex assembly suggesting silencing acts through posttranslationally modifying histones, to govern TFIIB recruitment to promoters. This project aims to identify transcription factors and molecular mechanisms responsible for transcriptional silencing. We will determine the essential regulators of silenced genes by backtracking from TFIIB binding to activator binding and quantify the relative occupancy of these crucial regulators at silenced versus active genes. Utilizing the silenced mating system in yeast to examine the mechanism of silencing in a natural context, the extent of occupancy of key regulatory factors at the silenced/active mating loci in "a" and "alpha" cells, will be measured by chromatin immunoprecipitation and real-time polymerase chain reaction. We will test the hypothesis that these key regulators control silencing through ongoing, reversible, dynamic competition rather than through frozen, inert structure.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供。子项目的主要支持 并且子项目的主要研究者可能是由其他来源提供的， 包括其他 NIH 来源。 子项目可能列出的总成本 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 表观遗传沉默，即染色质域内转录的可遗传抑制，在真核基因调控中至关重要。维持体内平衡需要涉及转录因子的基因调控事件的微妙平衡。沉默模式的失调会导致异常细胞的生长以及癌症的发展和增殖。然而，表观遗传沉默的分子机制仍不清楚。我之前的数据表明，沉默是在激活剂结合的下游、TFIB 招募和启动前复合物组装的上游启动的，这表明沉默通过翻译后修饰组蛋白起作用，以控制 TFIIB 招募到启动子。 该项目旨在确定负责转录沉默的转录因子和分子机制。我们将通过从 TFIIB 结合回溯到激活剂结合来确定沉默基因的重要调节因子，并量化这些关键调节因子在沉默基因与活性基因上的相对占用率。利用酵母中的沉默交配系统来检查自然环境下的沉默机制，通过染色质免疫沉淀和“a”和“α”细胞中沉默/活跃交配位点的关键调节因子的占据程度，以及实时聚合酶链式反应。我们将检验以下假设：这些关键监管机构通过持续的、可逆的、动态的竞争而不是通过冻结的惰性结构来控制沉默。