Regulation of Archaeal Transcription

项目摘要/摘要 必需的多亚单位rna聚合酶在转录的每个阶段都受到调节。 循环控制每个结构域中的基因表达。在许多情况下，基因的限速步骤 表达是在转录延伸过程中的，但我们的主要知识缺口仍然存在 对转录启动后调控的理解。我们的研究直接针对 古生物和真核细胞转录调控的突出问题。我们的 首要目标是建立调节启动后活动的分子机制。 并建立基于组蛋白的染色质对基因的调控 表情。改变染色质景观如何改变基因表达？如何，在 分子细节，改变RNA聚合酶活性的DO因子加速转录 在组蛋白结合的DNA上？原本极其稳定的转录延伸怎么可能 复合体被干扰以准确终止转录吗？这些复杂的挑战要求 继续关注定义基因表达的基本机制和 基因表达异常与疾病状态和癌症有关。 我们定义了古代转录和染色质系统是密切相关的，但很少 组成复杂的真核转录系统的不同版本。我们已经描述了 完整的古生物转录循环，并定义了三种控制转录的机制 终止决定，每个决定都揭示了与细菌和真核生物的相似之处 终止机制和要求继续实验以描绘保守的 破坏转录延伸复合体的机制。我们对如何 染色质结构调控基因表达也是不完整的。我们将利用 由天然组蛋白和组蛋白变体形成的单组蛋白染色质的简单性 在全基因组水平上建立由延伸的染色质结构施加的调节。我们 还将描述保守的古细菌-真核转录因子的分子活性 通过组蛋白结合的DNA修饰RNA聚合酶并加速转录。

Project Summary/Abstract The essential multi-subunit RNA polymerases are regulated at each stage of the transcription cycle to control gene expression in each Domain. In many cases the rate limiting step of gene expression is during transcription elongation, but major knowledge gaps remain in our understanding of post-initiation regulation of transcription. Our studies directly address outstanding questions of transcription regulation in archaeal and eukaryotic cells. Our overarching goals are to establish molecular mechanisms that regulate post-initiation activities of RNAP, and establish the regulation imposed by histone-based chromatin on gene expression. How does altering the chromatin-landscape alter gene expression? How, in molecular detail, do factors that modify the activities of RNA polymerase accelerate transcription on histone-bound DNA? How can the otherwise extremely stable transcription elongation complex be disrupted to terminate transcription accurately? These complex challenges demand continued attention to define the foundational mechanisms underlying gene expression and the aberrant gene expression associated with disease states and cancer. We defined that archaeal transcription and chromatin systems are closely related, yet minimal versions of the component complex eukaryotic transcription systems. We have described the complete archaeal transcription cycle and defined three mechanisms that control transcription termination decisions, each of which reveals similarities with bacterial and eukaryotic termination mechanisms and demands continued experimentation to delineate conserved mechanisms to disrupt the transcription elongation complex. Our understanding of how chromatin structure regulates gene expression is also incomplete. We will leverage the simplicity of single-histone chromatin formed with native histones and histone-variants to establish the regulation imposed by extended chromatin structures on a genome-wide level. We will also describe the molecular activities of conserved archaeal-eukaryotic transcription factors that modify RNA polymerase and accelerate transcription through histone-bound DNA.