Molecular analysis of RNAP II and III transcription

该提案的广泛的长期目标是在分子水平上确定RNA聚合酶II和III的转录起始机制。这些研究将导致更好地了解转录机制及其如何调节。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了解许多类型的疾病提供基础，例如癌症和涉及DNA修复缺陷的综合征，这些缺陷可能是由异常基因调控或转录机制突变引起的。该项目的具体目标是通过分子、生物化学和遗传学方法研究RNA聚合酶II和III利用的转录起始和再起始机制。新的因素，相互作用的TFIIA末端结构域在preinitiation复合物（PIC）的作用，将被确定。Pol II转录再起始的机制将被研究，重点是介体因子的作用和识别在再起始反应中使用的Pol II形式。将研究几种不同的介质复合物在基因调控中的作用。将阐明Pol III因子BRF的核心结构域的作用，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中锌带结构域的目标，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.