RNA polymerase II elongation control

项目摘要/摘要 RNA聚合酶II(POL II)的伸长控制在转录调控中起主要作用 在多细胞生物体的发育和分化过程中。这个过程是 以负伸长因子的默认行为为特征的，包括NELF和DSCIF 停止启动启动子附近聚合酶的转录。这些启动子近端停顿了一下 聚合酶通过TTF2或其他终止因子从模板中释放，或者 允许通过正延伸率的选择性动作进入生产性延伸率 因子P-TEFb。P-TEFb的细胞周期蛋白依赖性蛋白激酶活性受可逆调控 与HEXIM蛋白介导的7SK SNRNP的相关性。这项提议的主要目标是 为了进一步定义用于控制POL II伸长和实现高效 通过核小体转录。我们将使用新开发的生化方法和 全球技术，以阐明通过染色质实现转录的机制，作用 Pol II在维持启动子可及性中的作用，以及细胞周期蛋白依赖性激酶和 PAF1复合体在伸长控制中的作用。我们还将确定如何控制按键伸长 P-TEFb因子受7SK-SnRNP调控并检测mRNA帽甲基化的作用 在延伸率控制中。首席调查员是爱荷华大学的教授，这位 项目将在他的实验室提供的良好环境中进行，并在 爱荷华大学卡弗医学院。这里提出的研究应该显著地 增加我们对控制基因表达的机制的理解，这将有助于 解释癌症中发生的转录失调和延伸性劫持 控制机器受艾滋病病毒感染。

Project Summary/Abstract RNA polymerase II (Pol II) elongation control plays a major role in regulating transcription throughout development and differentiation of multi-cellular organisms. The process is characterized by the default action of negative elongation factors, including NELF and DSIF that halt transcription of initiated polymerases near promoters. These promoter-proximal paused polymerases are either released from the template by TTF2 or other termination factors or are allowed to enter productive elongation through the selective action of the positive elongation factor, P-TEFb. The cyclin dependent kinase activity of P-TEFb is regulated by reversible association with the 7SK snRNP mediated by HEXIM proteins. The main goal of this proposal is to further define the mechanisms utilized to control Pol II elongation and to enable efficient transcription through nucleosomes. We will use newly developed biochemical methods and global techniques to elucidate mechanisms enabling transcription through chromatin, the role of paused Pol II in maintaining promoter accessibility, and the role of cyclin dependent kinases and the PAF1 complex in elongation control. We will also determine how the key elongation control factor P-TEFb is regulated by the 7SK snRNP and examine the role of mRNA cap methylation in elongation control. The principle investigator is a professor at the University of Iowa and this project will be carried out in the excellent environment offered by his lab and the facilities in the University of Iowa, Carver College of Medicine. The studies proposed here should significantly increase our understanding of mechanisms controlling gene expression and this will be useful in explaining the dysregulation of transcription that occurs in cancer and the hijacking of elongation control machinery by the AIDs virus.