Molecular Modulator of RPA and RAD51 in Maintaining Genome Stability

DNA损伤构成了对遗传完整性的主要威胁，因此被牵连到遗传过程中。 癌症的发病机制。阐明保护基因组稳定性的机制对于 了解致癌的潜在机制。基因组的完整性不断受到威胁， 由细胞代谢过程以及环境因素引起的内源性和外源性因子 暴露，其中许多会阻碍正常的DNA复制并导致复制叉停滞。分叉需要 进行适当的修复和拯救，以防止DNA损伤和基因组不稳定， 肿瘤发生为了修复和挽救停滞的复制，一种调节DNA损伤的蛋白质网络 在细胞周期中，DNA修复、复制和细胞周期检查点被激活，以响应停滞的复制。 以稳定和重新启动失速的叉。然而，对分叉修复的机制知之甚少。 最近的研究表明，RAD51和RPA在失速叉处的平衡和动力学对于 叉稳定和重新启动。然而，如何调节RAD 51和RPA活动在很大程度上仍然难以捉摸。我们 最近的研究结果表明，高亲和力的单链DNA结合蛋白复合物（称为CST）可能 是RPA和RAD51在GC丰富的重复序列在复制应激反应的一个新的调节剂。的 本研究的目的是了解叉状神经元中CST、RAD51和RPA之间的分子关系 拯救，目的是提供新的见解，细胞如何抵消基因毒素引起的DNA损伤。 我们建议整合先进的生物化学、细胞生物学、细胞成像和下一代测序技术， 研究CST如何调节停滞位点的RPA结合并维持分叉进展的技术， 应激下稳定性（目标1），定义CST如何调节富含GC停滞位点的RAD 51活性（目标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）。从拟议的研究结果将提供新的信息的机制， 基因组稳定性维持，挽救停滞的复制和保持基因组稳定性。

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.