动粒是真核生物遗传物质分配过程中关键的多组分超结构蛋白质机器，其正确组装是细胞有丝分裂顺利完成的基础。酿酒酵母被视为优选的动粒组装研究对象，其动粒组装模式对理解其他真核生物动粒的功能机制有着重要的指导意义。在酿酒酵母中，Ctf3C-Cnn1-Wip1五元复合物担负着将外层动粒与着丝粒DNA联结在一起的关键生物学功能，但该复合物及其人源同源物的组装机制和结构-功能关系尚不清楚。在本项目的研究工作中，申请人拟通过X-射线晶体学及冷冻电镜方法并结合其他生物化学和细胞生物学技术手段，阐明Ctf3C-Cnn1-Wip1五元复合物各亚基间的相互作用关系和组装顺序，揭示该复合物联结上下游动粒蛋白的结构基础，探索上述相互作用关系对酿酒酵母动粒组装和有丝分裂过程的影响。上述研究工作的开展还将为深入理解该复合物人源同源物CENP-I/H/K/T/W组装异常在重大疾病发生发展中的病理学意义提供新的线索和思路。

The kinetochore is a disc-shaped multi-component superstructure protein machinery, found at the centromere of a chromatid, to which microtubules attach during cell division. The kinetochore of Saccharomyces cerevisiae is a preferred investigated subject both for eukaryotes kinetochore assembly mechanism and its structure-function relationship. In Saccharomyces cerevisiae, a five-element complex Ctf3C-Cnn1-Wip1, connecting outer-kinetochore associated with the centromere DNA, is essential for the chromosome segregation. In this project, using crystallography, CryoEM and other biochemical and cell biology methods, the applicant wants to elucidate the interaction relationship between each subunits of Ctf3C-Cnn1-Wip1 complex and the assembly mechanism of it; and reveal the structure bases that how does this complex interact with upstream and downstream kinetochore proteins; and explore how do above interactions influence the kinetochore assembly and cell division process in Saccharomyces cerevisiae. Above research would also provide new clues and opinions for the pathological significance of the abnormal assembly of the CENP-I/H/K/T/W (the human homolog of Ctf3C-Cnn1-Wip1) in the occurrence and the development of critical diseases.