真核生物有丝分裂中，姐妹染色单体的准确分离与平均分配依赖于着丝粒及其两侧的动粒复合体。CENP-A核小体是着丝粒的表观遗传标志，也是动粒组装的起始位点。动粒内层由多种着丝粒蛋白（CENPs）组装而成，本课题组曾揭示核心亚基CENP-H/I/K分子组装机制，但着丝粒识别与动粒组装机制尚不清晰，以往研究认为CENP-C与CENP-A的相互作用是动粒组装的起始。我们最新研究发现CENP-I与着丝粒DNA及CENP-A核小体存在直接相互作用，暗示CENP-I可能在着丝粒识别与动粒组装中发挥更重要的功能。本项目拟利用生物化学与生物物理学等方法，解析CENP-H/I/K与着丝粒DNA及CENP-A核小体的互作方式与结构基础，建立以CENP-H/I/K识别着丝粒新模型；联合细胞生物学及超分辨显微技术厘清动粒亚基间依赖关系与组装顺序，揭示CENP-H/I/K启动动粒组装的新机制。

In mitosis, the precise alignment and separation of sister chromosomes depend on the kinetochore, a protein complex on both sides of centromere. Kinetochore is a macromolecular complex assembled by dozens of core proteins (CENPs), which connects chromosomes and spindles. CENP-A nucleosome is the epigenetic marker of centromere localization as a starting position for kinetochore assembly. Our group has revealed the molecular assembly mechanism of core subunit CENP-H/I/K complex, but the mechanism of kinetochore assembly and centromere recognition is unclear.Previous studies believed that CENP-C depends on direct interaction with CENP-A and recruits other components to complete assembly of the whole kinetochore, but this model faces many questions. In this project, Our latest study found that CENP-I can interact directly with centromeric DNA and CENP-A nucleosomes, which means that CENP-I may play a more important role in centromere recognition and kinetochore assembly. In this project,We will use biochemical and biophysical methods to determine the CENP-H/I/K-NCPs-CENP-A structure, combined with cell biology and super resolution microscopy to clarify the dependence and assembly sequence among kinetochore subunits, and reveal the molecular mechanism of CENP-H/I/K involved in centromere recognition and kinetochore assembly initiation. elucidate the mechanism of CENP-H/I/K complex in centromere recognition and kinetochore assembly.