Molecular Modulator of RPA and RAD51 in Maintaining Genome Stability

RPA 和 RAD51 维持基因组稳定性的分子调节剂

• 批准号: 10055860
• 负责人: Weihang Chai
• 金额: $ 24.51万
• 依托单位: LOYOLA UNIVERSITY CHICAGO
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10055860
• 关键词: Molecular; Modulator; RPA; RAD51; Maintaining

DNA damage constitutes a major threat to genetic integrity, and has thus been implicated in the pathogenesis of cancer. Elucidating the mechanism safeguarding genome stability is important for understanding the mechanism underlying carcinogenesis. Genome integrity is constantly threatened by endogenous and exogenous agents arising from cellular metabolic processes as well as environmental exposure, many of which impede normal DNA replication and cause replication fork stalling. Stalled forks need to be properly repaired and rescued to prevent DNA lesions and genome instabilities that contribute to tumorigenesis. To repair and rescue stalled replication, a network of proteins regulating DNA damage response, DNA repair, replication, and cell cycle checkpoints are activated in response to stalled replication in order to stabilize and restart stalled forks. However, the mechanism underlying fork repair is poorly understood. Recent studies have revealed that the balance and dynamics of RAD51 and RPA at stalled forks are crucial for fork stabilization and restart. Yet how RAD51 and RPA activities are modulated remains largely elusive. Our recent findings suggest that the high-affinity single-stranded DNA binding protein complex known as CST may be a new modulator for RPA and RAD51 at GC-rich repetitive sequences in response to replication stress. The objective of this proposal is to understand the molecular relationship between CST, RAD51 and RPA in fork rescue, with the goal to provide novel insights into how cells counteract DNA damage caused by genotoxins. We propose to integrate advanced biochemical, cell biological, cell imaging, and next-gen sequencing techniques to examine how CST may regulate RPA binding at stalled sites and maintain fork progression and stability under stress (Aim 1), define how CST may modulate RAD51 activity at GC-rich stalled sites (Aim 2), and characterize the regulatory role of a surface-exposed region of CST in regulating RAD51 and RPA activities (Aim 3). Findings from the proposed research will provide novel information on the mechanism of genome stability maintenance of rescuing stalled replication and preserving genome stability.

DNA损害构成了对遗传完整性的主要威胁，因此与 癌症的发病机理。阐明该机理保护基因组稳定性对于 了解癌变的基础机制。基因组完整性不断受到威胁 由细胞代谢过程以及环境产生的内源性和外源性剂 暴露，其中许多阻碍了正常的DNA复制并导致复制叉停滞。停滞的叉子需要 要正确维修和救出，以防止DNA病变和基因组不稳定性有助于 肿瘤发生。要修复和救援停滞的复制，是调节DNA损伤的蛋白质网络 响应，DNA修复，复制和细胞周期检查点因停滞的复制而激活 为了稳定和重新开始停滞的叉子。但是，叉式修复的机制知之甚少。 最近的研究表明，停滞叉子的Rad51和RPA的平衡和动力学对于 分叉稳定并重新启动。然而，如何调制RAD51和RPA活动仍然难以捉摸。我们的 最近的发现表明，高亲和力的单链DNA结合蛋白复合物称为CST 响应复制应力，成为RPA和RAD51的新调节剂。这 该建议的目的是了解叉子中CST，RAD51和RPA之间的分子关系 救援，目的是提供有关细胞如何抵消基因毒素引起的DNA损伤的新见解。 我们建议整合先进的生化，细胞生物学，细胞成像和下一代测序 研究CST如何调节停滞位点的RPA结合并维持叉进程和 在压力下的稳定性（AIM 1），定义CST如何在富含GC的停滞位点调节RAD51活性（AIM 2）， 并表征CST表面暴露区域在调节RAD51和RPA中的调节作用 活动（目标3）。拟议研究的发现将提供有关机制机制的新信息 基因组稳定性维持拯救停滞的复制和保存基因组稳定性。