中心粒核心结构的装配与功能研究

中心体是动物细胞主要的微管组织中心，其内部组分中心粒还是纤毛和鞭毛装配的基体，在细胞分裂、运动、传递外界信号等过程中起重要作用。中心体异常与肿瘤和许多人类遗传病如小头畸形、纤毛病等相关，研究中心体的组装与调控机制具有重要的理论和医学价值。中心体装配包括核心的车轮结构、九组对称排列的微管，以及微管外侧的中心粒外周物质PCM。申请人过去的工作利用3D-SIM超高分辨显微技术揭示了中心粒外层和PCM区域蛋白的时空分布模式（Open Biology, 2012; NCB, 2016）。但受限于分辨率，中心粒核心结构的蛋白组装至今仍缺乏系统的研究。本项目的前期工作利用STED显微技术并优化了成像条件，实现对中心粒核心结构蛋白空间分布的解析。进一步，本项目将对这些蛋白的时间募集序列、上下游通路及蛋白相互作用网络进行研究。项目将揭示中心体早期装配的蛋白动态图谱，为理解中心体相关的细胞异变提供分子机理。

The centrosome is the main microtubule-organizing center in animal cells. It comprises of two barrel-shaped centrioles, one of which is surrounded by pericentriolar material (PCM). In non-dividing cells, the older centriole provides a template for cilium assembly. Extra copies of centrosomes are common features among cancer cells, whereas defects in ciliogenesis cause a wide range of human diseases including microcephaly and a group of disorders collectively known as the ciliopathies. Thus understanding how centrosomes are assembled and what controls it are important in both basic and biomedical research. Using 3D-SIM super-resolution microscopy, our and others’ work has revealed the organization of the PCM into distinct concentric domains, each populated by a specific set of proteins. Meanwhile, proteins that reside within 120 nm diameter of the centriole remain mostly unresolvable. We now applied STED super-resolution microscopy and were able to visualize the distribution of centriolar proteins at resolution of 55 nm. This enabled us to explore the protein architecture of centriole core structure, namely the cartwheel. Next, we would like to study the timely recruitment of these factors, their dependency and the regulation. The proposed work will not only reveal the fundamental knowledge of how the centrosome core structure is built, but will also provide clues to how cells go awry in cancer and in a number of heritable diseases whose roots lie in the malfunction of the centrosome.