Molecular analysis of RNAP II and III transcription

这项建议的广泛和长期目标是在分子水平上确定RNA聚合酶II和III启动转录的机制。这些研究将有助于更好地了解转录机制及其调控方式。这一点很重要，因为转录机制是许多信号转导、细胞周期和发育途径的最终目标。了解基因控制的基本过程将为理解许多类型的疾病提供基础，如癌症和涉及DNA修复缺陷的综合征，这些缺陷可能是由于基因调节异常或转录机制突变造成的。本项目的具体目标是通过分子、生化和遗传学方法研究RNA聚合酶II和III利用的转录起始和再起始机制。将确定与预起始复合体(PIC)中TFIIA末端结构域相互作用的新因子的作用。Pol II转录重新启动的机制将被研究，重点是中介因子的作用和在重新启动反应中使用的Pol II的一种形式的鉴定。我们将研究几种不同的介体复合体在基因调控中的作用。将阐明POL III因子BRF的核心区的作用，并与POL II因子TFIIB的同源区的作用进行比较。最后，将确定TFIIB和BRF中锌带结构域的靶标，比较这些结构域在POL II和III转录中的作用。

The broad, long-term objectives of this proposal are to determine at a molecular level, the mechanism of transcription initiation by RNA Polymerases II and III. These studies will lead to a better understanding of the transcription machinery and how it is regulated. This is important because the transcription machinery is the ultimate target of many signal transduction, cell cycle, and developmental pathways. Understanding the fundamental process of gene control will provide a basis for understanding many types of diseases such as cancer and syndromes involving DNA repair defects which can result from aberrant gene regulation, or from mutations in the transcription machinery. The specific aims of this project are designed to study through molecular, biochemical and genetic methods, the mechanisms of transcription initiation and reinitiation utilized by RNA Polymerases II and III. The role of novel factors, which interact with the TFIIA terminal domain in preinitiation complexes (PICs), will be identified. The mechanism of Pol II transcription reinitiation will be investigated with a focus on the role of the mediator factor and identification of a form of Pol II used in the reinitiation reaction. The role of several distinct mediator complexes in gene regulation will be studied. The role of the core domain of the Pol III factor BRF will be elucidated, and compared to the role of the homologous region of the Pol II factor TFIIB. Finally, the target of the zinc ribbon domains in TFIIB and Brf will be identified, comparing the role of these domains in Pol II and III transcription.