Dynamics of transcriptional regulatory complexes: Mechanism and function

转录调控复合物的动力学：机制和功能

• 批准号: 1817891
• 负责人: Keith Yamamoto
• 金额: $ 90.73万
• 依托单位: University of California-San Francisco
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-15 至 2020-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1817891&HistoricalAwards=false
• 关键词: Dynamics; transcriptional; regulatory; complexes; Mechanism

This project will define a new mechanism for dynamic regulation of gene expression. Turning a gene on or off is known to occur by assembly of a "regulatory protein machine" on the DNA near the gene. Such machines are composed of gene-specific combinations of proteins that work as a unit to switch the gene on or off in particular cells in particular ways. Emerging results indicate that mechanisms have evolved to actively disassemble these machines, resulting in a dynamic process of machine building and breakdown. This project will investigate how the dynamics of these regulatory protein machines alters the expression patterns of specific genes. The study is important because gene expression patterns have long been thought to be specified solely by the makeup of the regulatory machines without considering the role played by dynamics of machine building and breakdown. The results of this work will define factors involved in regulatory machinery dynamics and how they selectively modulate gene expression patterns. Notably, this research plan is integral to the career planning, development, and advancement to independence of an outstanding woman scientist, providing valuable experience in conceiving, executing and managing an original, impactful research program.Focusing on the glucocorticoid receptor (GR), this project will test the hypothesis that transcriptional regulatory complex (TRC) dynamics is a determinant of specific gene expression. The steroid hormone cortisol, which gates GR activity, circulates at levels that fluctuate according to circadian and ultradian (~1 hour) cycles, and spike in response to certain external cues. DNA-bound GR-containing TRCs are highly dynamic in vivo, with disassembly driven by molecular chaperones. This project will 1) define mechanisms of GR:DNA dynamics; 2) identify factors that target chaperones to TRCs to confer disassembly; and 3) determine effects of TRC dynamics on GR-regulated transcription. Mechanisms will be pursued in vitro and in cultured cells using molecular biological, biochemical, and proteomic methods to define how chaperone-mediated dynamics confers specific transcription patterns in response to glucocorticoid fluctuations. Revealing dynamics as a regulatory modality will advance understanding of context-specific metazoan gene expression, the principle mechanism that distinguishes cells types and shapes biological processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该项目将定义一种新的基因表达动态调控机制。 已知基因的开启或关闭是通过在基因附近的DNA上组装“调节蛋白机器”来实现的。 这种机器由基因特异性蛋白质组合组成，这些蛋白质作为一个单元以特定方式在特定细胞中打开或关闭基因。新出现的结果表明，机制已经发展到积极拆卸这些机器，导致机器的建设和故障的动态过程。本项目将研究这些调节蛋白机器的动力学如何改变特定基因的表达模式。这项研究很重要，因为基因表达模式长期以来一直被认为仅由调节机器的组成来指定，而不考虑机器构建和分解的动态所扮演的角色。 这项工作的结果将定义参与调控机制动力学的因素，以及它们如何选择性地调节基因表达模式。值得注意的是，这个研究计划是一个杰出的女科学家的职业规划，发展和独立的进步不可或缺的，在构思，执行和管理一个原创的，有影响力的研究计划提供宝贵的经验。这个项目将集中在糖皮质激素受体（GR），这个项目将测试的假设，转录调控复合物（TRC）的动态是一个特定的基因表达的决定因素。控制GR活性的类固醇激素皮质醇根据昼夜节律和超昼夜（约1小时）周期以波动的水平循环，并响应某些外部线索而飙升。DNA结合的GR-含有TRCs在体内是高度动态的，由分子伴侣驱动拆卸。该项目将1）定义GR的机制：DNA动力学; 2）确定靶向分子伴侣的TRC赋予拆卸的因素; 3）确定TRC动力学对GR调节转录的影响。机制将在体外和培养的细胞中使用分子生物学，生物化学和蛋白质组学方法来确定如何伴侣介导的动态赋予特定的转录模式，响应糖皮质激素的波动。揭示动态作为一种调控方式将促进对特定环境后生动物基因表达的理解，这是区分细胞类型和塑造生物过程的主要机制。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。