UNDERSTANDING THE ROLES OF RNA POLYMERASE I IN TRANSCRIPTION AND BEYOND

真核细胞部署至少三种多亚基DNA依赖性RNA聚合酶， 表达细胞存活和增殖所需的多种RNA。相比 表达单个RNA聚合酶的原核细胞，真核RNA聚合酶具有 进化成专门的细胞角色。RNA聚合酶I（Pol I）合成大部分RNA聚合酶。 Pol II合成信使RNA和大多数调节RNA，而Pol III合成信使RNA和大多数调节RNA。 合成转移RNA和5S核糖体RNA。虽然这种“分工”之间的 多年来，核政策一直受到重视，我们对核政策的理解存在巨大差距。 真核生物RNA聚合酶之间的功能差异仍然存在。酶是如何 这些酶的性质不同吗？这些功能上的差异是如何影响 转录相关的转录因子？不同的酶性质是如何 Pos影响其独特的细胞作用？这些问题的答案基本上是 对理解真核生物学很重要。 众所周知，核糖体的合成速率与细胞的增殖速率成正比。 生长和增殖。因此，世界各地的一些实验室正在寻找新的抑制剂 作为潜在的抗癌化疗药物。自转录的 核糖体DNA的聚合是核糖体合成的第一个限速步骤， 作为开发这些抑制剂的关键目标。为了选择性地抑制一种RNA 在不影响其他聚合酶的情况下，了解聚合酶的基本性质至关重要。 酶以及控制酶的细胞机制。因此，在本发明中， 定义Pol I活性及其细胞作用具有直接的翻译价值。 通过定义真核转录的景观和Pol I的许多细胞作用， 该项目将揭示进化生物学基本问题的答案，同时为人类提供信息。 正在进行的研究旨在核糖体RNA合成的治疗靶向。达到这些 目标，我们的实验室已经开发了一个强大的实验方法平台，包括 生物化学、生物物理学、遗传学和基因组学方法。我们开创了 制定实验和分析策略， 彻底定义RNA聚合酶I的功能特性。本项目的总体目标 是利用这些实验优势来影响我们对真核生物的整体理解， 基因表达，并为正在进行的和未来的研究奠定基础，旨在治疗 抑制Pol I。

Eukaryotic cells deploy at least three multisubunit, DNA-dependent RNA polymerases to express the robust variety of RNAs required for cell survival and proliferation. In contrast to prokaryotic cells which express a single RNA polymerase, eukaryotic RNA polymerases have evolved into specialized cellular roles. RNA polymerase I (Pol I) synthesizes the majority of ribosomal RNA, Pol II synthesizes messenger RNA and most regulatory RNAs, whereas Pol III synthesizes transfer RNA and the 5S ribosomal RNA. While this "division of labor" among the nuclear Pols has been appreciated for many years, substantial gaps in our understanding of the functional divergence between the eukaryotic RNA polymerases remain. How do the enzymatic properties of these enzymes differ? How do these functional differences influence regulation of transcription by associated transcription factors? How do divergent enzymatic properties of the Pols impact their unique cellular roles? The answers to these questions are fundamentally important for understanding eukaryotic biology. It is well established that the rate of ribosome synthesis is proportional to the rates of cell growth and proliferation. As a consequence, several labs around the world seek novel inhibitors of ribosome synthesis as potential anticancer chemotherapy agents. Since transcription of the ribosomal DNA by Pol I is the first, rate-limiting step in ribosome synthesis, Pol I has emerged as a key target for the development these inhibitors. In order to selectively inhibit one RNA polymerase without affecting the others, it is crucial to understand the fundamental properties of the enzymes as well as the cellular mechanisms by which the enzymes are controlled. Thus, defining Pol I activity and its cellular roles has immediate translational value. By defining the landscape of eukaryotic transcription and the many cellular roles of Pol I, this project will reveal answers to fundamental questions in evolutionary biology while informing ongoing studies aimed at therapeutic targeting of ribosomal RNA synthesis. To reach these goals, our lab has developed a robust platform of experimental approaches including biochemical, biophysical, genetic, and genomic methodologies. We have pioneered the development of both the experimental and analytical strategies required to rigorously and thoroughly define the functional properties of RNA polymerase I. The overall goal of this project is to leverage these experimental strengths to impact our overall understanding of eukaryotic gene expression and to lay the foundation for ongoing and future studies aimed at therapeutic inhibition of Pol I.