Pol III-Related Mechanism of Transcription Through Chromatin

染色质转录的 Pol III 相关机制

• 批准号: 0234493
• 负责人: Vasily Studitsky
• 金额: $ 42.23万
• 依托单位: Wayne State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-03-01 至 2003-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0234493&HistoricalAwards=false
• 关键词: Pol; III; Related; Mechanism; Transcription

The genome of higher organisms is organized in DNA-protein complexes called chromatin. Chromatin is designed to allow tight DNA packaging and proper functioning of DNA, as well as regulation of enzymes such as nuclear DNA and RNA polymerases. RNA polymerases transcribe chromatin (make RNA copies of one DNA strand). Transcribed genes are organized in chromatin raising the question of how RNA polymerases deal with chromatin. The primary features of this process have been recapitulated in vitro. In particular, the mechanism used by eukaryotic RNA polymerase III (pol III) is accompanied by transient chromatin remodeling at the sites of transcription followed by recovery of chromatin structure. This project focuses on further mechanistic analysis of this mechanism and its regulation using defined chromatin templates. The mechanism of transcription through chromatin by pol III will be analyzed using biochemical approaches, electron cryo-microscopy and fluorescence resonance energy transfer (FRET). Completion of this project will result in development of novel defined chromatin templates and new techniques useful for analysis of various DNA-protein interactions in chromatin, including interaction of specific regulatory factors and enzymes of DNA metabolism (such as enzymes involved in DNA replication and repair) with chromatin. The data obtained will lead to better understanding of the mechanism of chromatin transcription in terms of the structures of the DNA-protein complexes formed during this process. Since the mechanisms of DNA replication, ATP-dependent chromatin remodeling and the mechanism of transcription through chromatin by pol III have many common features, the results obtained during this research will help to understand all these processes.

高等生物的基因组由DNA-蛋白质复合体组成，称为染色质。染色质的设计允许紧密的DNA包装和DNA的正常功能，以及对核DNA和RNA聚合酶等酶的调节。RNA聚合酶转录染色质(制作一条DNA链的RNA副本)。转录的基因是在染色质中组织起来的，这就提出了RNA聚合酶如何处理染色质的问题。这一过程的主要特征已在体外进行了概括。特别是，真核RNA聚合酶III(PolIII)使用的机制伴随着转录位点的瞬时染色质重塑，随后染色质结构恢复。这个项目的重点是使用已定义的染色质模板进一步分析这一机制及其调节。将使用生化方法、电子冷冻显微镜和荧光共振能量转移(FRET)分析PolIII通过染色质转录的机制。该项目的完成将导致开发新定义的染色质模板和新技术，用于分析染色质中各种DNA-蛋白质相互作用，包括特定调节因子和DNA代谢酶(如参与DNA复制和修复的酶)与染色质的相互作用。获得的数据将有助于更好地理解染色质转录过程中形成的DNA-蛋白质复合体的结构的机制。由于PolIII的DNA复制、依赖于ATP的染色质重塑和通过染色质转录的机制有许多共同的特点，因此本研究的结果将有助于理解所有这些过程。