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Mechanisms of R-loop-Associated Genome Instability

R 环相关基因组不稳定性的机制

基本信息

批准号：
10806721
负责人：
Karlene A Cimprich
金额：
$ 1.09万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-07-01 至 2024-04-30
项目状态：
已结题

项目摘要

PROJECT SUMMARY (from parent application) Replication and transcription are fundamental physiological processes, yet paradoxically they both threaten genome stability. Replication forks encounter various types of endogenous and exogenous obstacles that keep them from accurately completing DNA replication. Recent studies suggest that the deleterious effects of transcription could be a consequence of R-loops, three-stranded nucleic acid structures containing an RNA-DNA hybrid and a region of single-stranded DNA. R-loops occur throughout the genome of mammalian cells and regulate various aspects of gene expression, but their accumulation leads to DNA damage, particularly when cells are undergoing DNA replication. Increasing evidence suggests that conflicts between transcription- associated R-loops and replication protein complexes are important factors underlying genome instability, but the specific mechanisms driving this instability are currently unknown. The long-term goal of this research program is to understand how cells distinguish and resolve regulatory and deleterious R-loops, and how this is perturbed in human disease. It is hypothesized that R-loops are dynamic structures that become susceptible to processing when they accumulate, leading to the formation of DNA breaks and ultimately resulting in genome instability. The object of this application is to define how R-loops are recognized and processed in the cells throughout the cell cycle, to determine where in the genome processing occurs, and to determine how conflicts with the replication machinery contribute to R-loop processing. In the first aim, the processing of R-loops by cellular endonucleases involved in DNA repair will be explored in cells using molecular and cell biological approaches. In the second aim, the sites and products of R-loop formation and processing will be identified and mapped. These studies will take advantage of cutting-edge genomic approaches that have been developed to map the spatial distribution of R-loops and R-loop processing products throughout the genome. Finally, in the third aim, the impact of an R-loop on collisions between replication and transcription machineries will be studied in cells. These studies will take advantage of a novel system recently developed to control such collisions and R-loop formation in the context of the replication fork and recent break-mapping strategies.

项目摘要（来自母公司申请）复制和转录是基本的生理过程，但矛盾的是，它们都威胁着基因组稳定性复制分叉遇到各种类型的内源性和外源性障碍，使其无法准确完成DNA复制。最近的研究表明，转录可能是R环（含有RNA-DNA的三链核酸结构）的结果杂交体和单链DNA区域。R环存在于哺乳动物细胞的整个基因组中，调节基因表达的各个方面，但它们的积累会导致DNA损伤，特别是当细胞正在进行DNA复制。越来越多的证据表明，转录之间的冲突- 相关的R环和复制蛋白复合物是基因组不稳定性的重要因素，驱动这种不稳定性的具体机制目前尚不清楚。这项研究的长期目标是该计划旨在了解细胞如何区分和解决调节性和有害的R环，以及这是如何人类疾病的困扰。假设R环是动态结构，当它们积累时，它们会进行加工，导致DNA断裂的形成，并最终导致基因组不稳定这个应用程序的目的是定义如何在细胞中识别和处理R环在整个细胞周期，以确定在基因组处理发生，并确定如何冲突，与复制机制一起参与R环加工。在第一个目标中，通过将使用分子和细胞生物学方法在细胞中探索参与DNA修复的细胞核酸内切酶。接近。在第二个目标中，将识别R环形成和加工的位点和产物，映射。这些研究将利用已开发的尖端基因组方法，绘制整个基因组中R环和R环加工产物的空间分布图。最后在第三个目标，将研究R环对复制和转录机制之间碰撞的影响在细胞中。这些研究将利用最近开发的一种新系统来控制这种碰撞，在复制叉和最近的断裂映射策略的背景下的R环形成。