Studies of the Rad60-Smc5-Smc6 DNA Repair Complex

多种DNA修复途径已经发展到在面对持续的遗传毒性剂的弹幕时保持基因组的完整性。各种DNA修复机制的缺陷导致癌症的强烈倾向。除了DNA修复途径外，复制检查点也起着重要作用。响应于S期损伤，复制检查点通过协调细胞反应（例如细胞周期停滞、叉稳定化和DNA修复）来维持基因组稳定性。癌症风险因复制检查点所需的人类蛋白质突变而升高。该建议旨在探索DNA修复和复制检查点之间的重要接口，对此知之甚少。这些研究将使用裂殖酵母，裂殖酵母，它已被证明在分析DNA修复和检查点途径，是在人类中保守的宝贵。DNA修复蛋白Rad 60与复制检查点激酶CXCR 4相互作用。Rad 60是DNA修复和基因组完整性所需的Smc 5-Smc 6复合物的一部分。Rad 60受Cds 1依赖性调节，因此，第一个目的是解偶联Cds 1-Rad 60通信并研究对基因组稳定性的影响。第二个目标是了解Rad 60的功能，这反过来又揭示了一个重要的机制，通过该机制，Cynthia维持基因组。第三个目的是探索Smc 5-Smc 6复合物的功能，Rad 60是其中的一部分。Smc 5-Smc 6复合物可能在染色体结构中起作用，从而促进DNA修复。关于染色质结构在DNA修复中的作用知之甚少，因此这些研究将有助于阐明这种联系。在这项研究中获得的结果可能会引发上述蛋白质的人类同源物的类似研究，从而更好地了解人类复制检查点和DNA修复之间的界面。

Multiple DNA repair pathways have evolved to maintain genomic integrity in the face of a constant barrage of genotoxic agents. Defects in various DNA repair mechanisms result in a strong predisposition to cancer. In addition to DNA repair pathways, the replication checkpoint plays an important role. In response to S-phase insults, the replication checkpoint maintains genomic stability by coordinating cellular responses such as; cell-cycle arrest, fork stabilization and DNA repair. Cancer risk is elevated by mutations in human proteins that are required for the replication checkpoint. This proposal is aimed at exploring the important interface between DNA repair and the replication checkpoint, about which little is known. These studies will employ the fission yeast, Schizosaccharomyces pombe, which has proven invaluable in the analysis of DNA repair and checkpoint pathways that are conserved in humans. The DNA repair protein Rad60 interacts with the replication checkpoint kinase, Cdsl. Rad60 is part of the essential Smc5-Smc6 complex that is required for DNA repair and genomic integrity. Rad60 is subject to Cdsl-dependent regulation and therefore, the first aim is to uncouple Cdsl-Rad60 communication and study the effects on genomic stability. The second aim focusses on understanding the function of Rad60, which in turn should reveal an important mechanism through which Cdsl maintains the genome. The third aim is to explore the function of the Smc5-Smc6 complex, of which Rad60 is a part. The Smc5-Smc6 complex likely plays a role in chromosome structure and thereby facilitates DNA repair. Little is known about the role of chromatin structure in DNA repair and therefore these studies will help elucidate this connection. Results obtained in this study will likely prime analogous studies of the human homologues of the above proteins, resulting in a better understanding of the interface between the replication checkpoint and DNA repair in humans.