Histone Eviction and Mediator Function in Transcriptional Activation in Yeast

酵母转录激活中的组蛋白驱逐和介体功能

• 批准号: 0949722
• 负责人: Randall Morse
• 金额: $ 55.62万
• 依托单位: Health Research Incorporated/New York State Department of Health
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0949722&HistoricalAwards=false
• 关键词: Histone; Eviction; Mediator; Function; Transcriptional

Intellectual merit: The long term goal of this project is to gain new understanding into mechanisms of transcriptional control in eukaryotes. Regulation of gene transcription is central to growth, development, and response to environment in all cells; thus, understanding transcriptional control is a central goal in genetics. The specific goals of this project are to gain new insight into chromatin remodeling during gene activation, and into the role of the Mediator complex in gene regulation. DNA in higher organisms, including humans, is packaged into nucleosomes by wrapping around an octamer of histone proteins. This creates a potential impediment to protein-DNA interactions needed for transcription of DNA into RNA, and so at many genes these nucleosomes must be remodeled to allow transcription to occur. This project will focus on chromatin remodeling at the CHA1 gene in the yeast Saccharomyces cerevisiae. Genetic and biochemical approaches will be used to examine the mechanism by which remodeling leads to histone eviction at CHA1 and at additional inducible promoters. Studies will also be conducted to investigate the role of the Mediator complex in transcriptional regulation in yeast. Mediator is a large, multi-subunit complex, comprising tail, middle, and head modules that bridges activators, whose binding is the initial step in gene activation, and the general transcription machinery. Mediator is highly conserved across the eukaryotic kingdom, and serves as a conduit for many regulatory signals, but the mechanism by which it controls gene expression is not well understood. Research will be carried out to determine whether one specific part of the Mediator complex, called the tail module, has specific functions aside from its requirement for recruitment of the middle and head modules, and to determine the role of the tail module of Mediator in CHA1 activation, in genome-wide recruitment of Mediator, and in transcriptional repression. Overall, this project will provide new information on fundamental aspects of transcriptional activation which at present is poorly understood. Transcriptional mechanisms are well conserved across eukaryotes. Hence, the information gained from this work will be broadly applicable.Broader impactThis research will include training of a graduate student and postdoctoral fellow. In addition, undergraduates will be recruited to participate in this project as summer interns, to be funded by REU supplements. The project will also result in generation of large data sets from microarray studies, and these will be made publicly available, both by providing raw data files to a public repository (GEO), and by making more user-friendly, processed data files available for download from the principal investigator's web site.

智力优势：该项目的长期目标是获得对真核生物转录控制机制的新认识。基因转录调控是所有细胞生长、发育和对环境反应的核心；因此，理解转录控制是遗传学的中心目标。该项目的具体目标是获得基因激活过程中染色质重塑的新见解，以及介导复合物在基因调控中的作用。在包括人类在内的高等生物中，DNA被包裹在组蛋白八聚体周围，被包装成核小体。这对DNA转录为RNA所需的蛋白质-DNA相互作用造成了潜在的障碍，因此在许多基因上，这些核小体必须被改造以允许转录发生。本项目将重点研究酿酒酵母CHA1基因的染色质重塑。遗传学和生物化学方法将用于研究重塑导致CHA1和其他诱导启动子上组蛋白排出的机制。研究还将进行调查调解复合体在酵母转录调节中的作用。中介体是一个大的多亚基复合物，包括尾部、中间和头部模块，连接激活子和一般转录机制，激活子的结合是基因激活的第一步。在整个真核生物王国中，介质是高度保守的，并作为许多调节信号的管道，但其控制基因表达的机制尚不清楚。研究将确定Mediator复合体的一个特定部分，称为尾部模块，除了需要招募中间和头部模块外，是否具有特定的功能，并确定Mediator的尾部模块在CHA1激活、全基因组招募和转录抑制中的作用。总的来说，这个项目将提供关于转录激活的基本方面的新信息，这在目前是知之甚少的。转录机制在真核生物中是保守的。因此，从这项工作中获得的信息将广泛适用。本研究将包括培养一名研究生和一名博士后。此外，将招募本科生作为暑期实习生参与该项目，由REU补充资助。该项目还将产生来自微阵列研究的大型数据集，这些数据集将通过向公共存储库（GEO）提供原始数据文件，以及通过从主要研究者的网站上提供更方便用户的、处理过的数据文件来公开提供。