Mechanism Transcript Elongation in Chromatin

染色质转录本延伸的机制

• 批准号: 7880959
• 负责人: VASILY M STUDITSKY
• 金额: $ 41.33万
• 依托单位: UNIV OF MED/DENT NJ-R W JOHNSON MED SCH
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-17 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7880959
• 关键词: Address; Biochemical; Cells; Chromatin; Chromatin Structure; DNA Polymerase II; DNA-Directed RNA Polymerase; Data; Development; Dissociation; Electron Microscopy; Elongation Factor; Fluorescence Resonance Energy Transfer; Gene Expression Regulation; Genes; Genetic Transcription; Goals; Histones; In Vitro; Life; Modification; Molecular; Molecular Chaperones; Molecular Genetics; Mono-S; Nucleosomes; Oncogenes; Play; Polymerase; Polynucleosome; Positioning Attribute; Process; RNA; RNA Binding; RNA Polymerase II; Regulation; Regulator Genes; Research; Role; System; Techniques; Testing; Transcript; Transcription Initiation; Transcription Process; Transcriptional Regulation; Work; chromatin modification; clinically significant; histone modification; improved; in vivo; novel strategies; promoter; research study; single molecule; transcription factor; tumorigenesis

DESCRIPTION (provided by applicant): The process of transcription is essential for all living cells. Transcription is accomplished in four steps: promoter binding, RNA chain initiation, RNA transcript elongation, and RNA transcript termination. Regulation of transcription can occur at each of these steps. Recent studies suggest that transcript elongation by RNA polymerase II is one of the major targets of gene regulation. It has been established that regulation of gene expression at the level of transcript elongation involves factors interacting with histones. These factors facilitate transient displacement of histones from chromatin during transcript elongation and modify the rate of transcription through chromatin. The long-term research goal of this proposal is to understand the mechanism and the regulation of transcript elongation by eukaryotic RNA polymerases in chromatin. When eukaryotic genes are activated for transcription, their chromatin structure changes to accommodate transcription factors and to allow efficient transcription by RNA polymerases. However, for many genes there is evidence that transcribed regions are covered with nucleosomes. This raises the questions: 1. How do polymerases transcribe through the nucleosome barrier? 2. How do the factors interacting with histones change the rate of transcript elongation? These questions will be addressed in a highly purified transcription system in vitro. We will analyze transcription of homogeneous and well-defined mono- and polynucleosomal chromatin templates using biochemical, fluorescent, molecular genetic and single-molecule techniques. Our experiments will be focused on analysis of eukaryotic RNA polymerase II. The specific aims are: 1. To test whether transient displacement of histones from nucleosome is the rate-limiting step during transcript elongation. 2. To determine whether elongation factors such as FACT facilitate transcription through chromatin by interacting with histones within polymerase-engaged nucleosomes. The discovery that some elongation factors play important roles in oncogenesis underscores the potential clinical significance of analysis of the mechanism of transcript elongation through chromatin.

描述（由申请人提供）：转录过程对所有活细胞都是必不可少的。转录通过四个步骤完成：启动子结合、RNA链起始、RNA转录延伸和RNA转录终止。转录调控可以发生在这些步骤中的每一步。近年来的研究表明，RNA聚合酶II的转录延伸是基因调控的主要目标之一。已经确定转录延伸水平的基因表达调控涉及与组蛋白相互作用的因子。这些因子在转录延伸过程中促进组蛋白从染色质上的瞬时位移，并通过染色质改变转录速率。本课题的长期研究目标是了解真核RNA聚合酶在染色质中转录延伸的机制和调控。当真核基因被激活转录时，它们的染色质结构改变以适应转录因子并允许RNA聚合酶有效转录。然而，有证据表明，许多基因的转录区被核小体覆盖。这就提出了以下问题：1。聚合酶如何通过核小体屏障进行转录？2. 与组蛋白相互作用的因子如何改变转录本延伸率？这些问题将在体外高度纯化的转录系统中得到解决。我们将使用生化，荧光，分子遗传学和单分子技术分析均匀和明确的单核体和多核体染色质模板的转录。我们的实验将集中在真核RNA聚合酶II的分析。具体目标是：1。测试组蛋白从核小体的瞬时位移是否是转录物延伸过程中的限速步骤。2. 确定伸长因子如FACT是否通过染色质与参与聚合酶的核小体中的组蛋白相互作用促进转录。一些延伸因子在肿瘤发生中发挥重要作用的发现，强调了通过染色质分析转录物延伸机制的潜在临床意义。