DNA-蛋白质共价交联损伤修复蛋白复合物的结构与功能研究

DNA-蛋白质共价交联的损伤（DPCs）是一种严重的DNA损伤，会阻碍DNA的转录和复制，从而影响细胞分裂乃至引起细胞的死亡。DPCs损伤修复缺陷的人更易患早衰症和肝细胞癌等疾病。研究表明，酵母中DPCs的损伤修复的主要通路牵涉到蛋白酶Wss1，分离酶Cdc48，Cdc48适配因子等多个蛋白，并受到蛋白质f翻译后修饰如泛素化和苏素化的调控。在Cdc48蛋白帮助下，Wss1与底物相互作用，底物被wss1切割并运送到蛋白酶体降解。然而，Wss1与Cdc48以对DPCs损伤进行修复的细节尚不清楚。我们希望通过解析以Wss1、Cdc48和不同底物复合物为主体的一系列蛋白三维结构，开展生化功能研究，最终阐明机体修复DPCs损伤的详细机制，从而为抗衰老和肿瘤的预防及治疗提供结构和理论基础。

Covalent DNA–protein crosslinks (DPCs) are severe DNA lesions, which may impede DNA transcription and replication，therefore influence cell division and cause cell death. People with DPCs repairing defects are more likely to suffer from diseases such as premature aging and hepatocellular carcinoma. Reseaches indicated that one main repairing pathway in yeast is that protease Wss1 proteolytically breaks down the bulk of the protein components of DPCs, in the aid of the segregase Cdc48 and cdc48-adaptors. and is regulated by protein post-translation modification such as ubiquitination and sumolyation. Cdc48 can help Wss1 bind to the substrate protein. The substrate protein will be hydrolyzed by Wss1 and be transfered to proteasome where it will be degradated. However， detailed repairing mechanism by which Wss1, Cdc48 coordinatedly resolve DPCs is still unclear..We plan to determing a number of protein and protein complex 3D-structures, including Wss1，cdc48 in complex with various substrates， together with biochemical experiments to elucidate the detailed DPCs repairing mechanism. A better understanding of the repairing mechanism will provide the structure and theoretical basis for anti-aging and treatment of cancer.