Mechanisms that Couple Chromatin Modifications to Transcription

项目摘要 这个研究项目的目标是阐明调节转录的蛋白质和机制。 在染色质的背景下，这是一个对每个真核细胞都至关重要的过程。核小体对RNA构成障碍 聚合酶II(POL II)，为了准确和有效的基因表达，必须克服它，并且它的性质 相互作用受翻译后修饰的调节。在转录延伸过程中，保守的 一组因素与POL II组合在一起，并通过改变稳定性、定位和后置来促进其运输 核小体的翻译修饰状态。该提案解决了与以下方面相关的三大挑战 真核转录延伸因子的这些功能。(1)通过什么机制 转录延长因子将染色质变化，包括组蛋白修饰，与RNA合成相结合？ (2)这些表观遗传修饰的模式是如何确定的？(3)主要的和 POL II延伸机核心部件的间接作用？我们将探讨这些问题 通过对Paf1复合体(Paf1C)及其相互作用蛋白的全面分析。Paf1C是一种 高度保守的转录延伸因子，在活性小体上与POL II全局结合 基因。Paf1C的多功能特性为揭示转录是如何耦合的提供了一个独特的机会 共同转录的事件。为此，一种包括创新的基因和蛋白质组的多方面方法 筛查、机械生物化学和基因组学将被部署。该项目将决定Paf1C如何 刺激关键的组蛋白修饰，并与具有遗传联系的染色质重塑因子相互作用 前列腺癌。深入研究Paf1C和POL II延伸复合体Will之间的相互作用 揭示在空间上限制依赖Paf1C的染色质变化为活性的分子机制 基因。最后，Paf1C的初级和亚基特异性功能，以及细胞通路 补偿它的缺席，将被确定。研究将在酿酒酵母中进行，以 充分利用为该系统开发的复杂工具。鉴于所有蛋白质的保守性很强 和组蛋白修饰研究，这项工作产生的概念进展将直接 对理解人类基因调控的意义，在这一过程中的缺陷导致广泛的 癌症和其他疾病的范围。

Project Summary The goal of this research program is to elucidate the proteins and mechanisms that regulate transcription within the context of chromatin, a process critical to every eukaryotic cell. Nucleosomes pose barriers to RNA polymerase II (Pol II) that must be overcome for accurate and efficient gene expression, and whose properties and interactions are modulated by post-translational modification. During transcription elongation, a conserved set of factors assembles with Pol II and facilitates its transit by altering the stability, positioning, and post- translational modification states of nucleosomes. The proposal addresses three major challenges related to these functions of eukaryotic transcription elongation factors. (1) What are the mechanisms by which transcription elongation factors couple chromatin changes, including histone modifications, to RNA synthesis? (2) How are the patterns of these epigenetic modifications determined? (3) What are the primary versus indirect functions of core components of the Pol II elongation machinery? These questions will be approached through a comprehensive analysis of the Paf1 complex (Paf1C) and proteins with which it interacts. Paf1C is a highly conserved transcription elongation factor that globally associates with Pol II on the bodies of active genes. The multifunctional nature of Paf1C affords a unique opportunity to reveal how transcription is coupled to co-transcriptional events. To this end, a multifaceted approach comprising innovative genetic and proteomic screens, mechanistic biochemistry, and genomics will be deployed. This project will determine how Paf1C stimulates critical histone modifications and interfaces with a chromatin remodeling factor with genetic links to prostate cancer. In-depth studies of the interactions between Paf1C and the Pol II elongation complex will uncover the molecular mechanisms that spatially constrain Paf1C-dependent chromatin changes to active genes. Finally, the primary and subunit-specific functions of Paf1C, as well as the cellular pathways that compensate for its absence, will be determined. The studies will be performed in Saccharomyces cerevisiae to capitalize on the sophisticated tools developed for that system. Given the strong conservation of all proteins and histone modifications studied, the conceptual advances that arise from this work will have direct implications for the understanding of gene regulation in humans, where defects in this process cause a wide range of cancers and other diseases.