Mechanism of Specific Initiation by RNA Polymerase II

真核细胞核糖核酸酶II识别的启动子转录启动频率的调节在发育和分化过程中改变基因表达模式起着重要作用。人们对这种调控的机制(S)知之甚少，甚至对施加调控的转录启动的基本机制也知之甚少。我们的目标是将RNA聚合酶II的转录启动分为不同的机制步骤，鉴定参与每个步骤的蛋白质和DNA序列，并测试各种II类启动子机制的共性，以期了解这些步骤中哪些是调控的目标，以及这种调控是如何完成的。除了RNA聚合酶II外，已经部分纯化了四种蛋白质因子，它们是体内重建转录所必需的。它们明显的作用表明，在转录启动之前，一个多蛋白复合体在启动子上组装。这可以在这个系统中进行调查。霍利博士在培训期间曾与原核生物和真核生物的RNA聚合酶打交道，并为该领域带来了真正的专业知识。这个项目在资金方面具有很高的优先级。

Regulation of the frequency of transcription initiation from promoters recognized by eukaryotic RNAase II plays a major role in changing the pattern of gene expression during development and differentiation. Very little is known about the mechanism(s) of this regulation, or, indeed, about the basic mechanism of transcription initiation upon which regulation is imposed. The goal here is to dissect transcription initiation by RNA polymerase II into different mechanistic steps, to identify the proteins and DNA sequences that contribute to each step, and to test the generality of the mechanisms among various class II promoters with the hope of understanding which of these steps are targets of regulation and how is this regulation accomplished. Four protein factors have been partially purified that are required in addition to RNA polymerase II for reconstitution transcription in vivo. Their apparent roles suggest that a multi-protein complex assembles at the promoter prior to transcription initiation. This can be investigated in this system. Dr. Hawley has worked with both prokaryotic and eukaryotic RNA polymerase during her training and brings a real expertise to the field. This project takes a very high priority for funding.