Molecular basis of centriole duplication

中心粒复制的分子基础

• 批准号: 10014716
• 负责人: Kyung Lee
• 金额: $ 135.48万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10014716
• 关键词: Abnormal Cell; Aneuploidy; Animals; Architecture; Biogenesis; Biological Process; C-terminal; Cell Cycle; Cell Cycle Progression; Cell division; Cell physiology; Cells; Cellular biology; Centrioles; Centrosome; Chromosome Segregation; Client; Complex; Data; Defect; Development; Disease; Ensure; Etiology; Eukaryotic Cell; Event; Exhibits; Future; Goals; Higher Order Chromatin Structure; Human; In Vitro; Life; Malignant Neoplasms; Mediating; Membrane; Microtubule-Organizing Center; Mitotic spindle; Molecular; Names; Organelles; Organism; PLK1 gene; Phase; Play; Polo-Box Domain; Procentriole; Process; Property; Proteins; Research; Role; Site; Subcellular structure; Work; X-Ray Crystallography; biophysical techniques; density; genome integrity; human disease; in vivo; macromolecular assembly; nanoscale; novel; scaffold; self assembly; self organization; single molecule

The centrosome, a unique membrane-less multiprotein organelle that serves as the main microtubule-organizing center in animal cells, plays a pivotal role in the orderly progression of the cell cycle. Since faulty assembly and duplication of the centrosome results in abnormal cell division, which then leads to various human disorders, elucidating the molecular mechanisms underlying centrosome assembly and function is likely a key step to understanding the etiology of centrosome-associated human diseases. By combining cell biology with biophysical methods and X-ray crystallography, we demonstrated that two pericentriolar scaffolds, Cep152 and Cep63, possess intrinsic activity of co-phase-separating into condensates and form a heterotetrameric complex that serves as a building block for generating a nanoscale cylindrical self-assembly around a centriole. Remarkably, two short uncharacterized regions named Self-Assembly Motifs (one each from Cep63 and Cep152) cooperatively conferred physicochemical properties that allowed them to undergo density transition and self-assemble into a cylindrical architecture. Interestingly, the Cep152-Cep63 condensates exhibited a rapid turnover, underwent fusion with other assemblies, and carried out a significant degree of internal rearrangement within a condensate. A Cep152-Cep63 cylindrical architecture that self-assembled on a flat substrate displayed a decreased but still detectable level of dynamic turnover. Interestingly, Polo-like kinase 4 (Plk4), a key regulator of centriole biogenesis, also dynamically phase-separated from a Cep152-bound state around a centriole (i.e., ring state) into a dot-like, low-nanoscale spherical condensate (i.e., dot state) upon autophosphorylating its C-terminal cryptic polo-box domain. Additional in vitro and in vivo data suggest that the Plk4 condensate serves as an assembling body at the future procentriole assembly site by amassing downstream procentriole assembly components such as STIL and Sas6 and facilitating Plk4-mediated centriole biogenesis. Thus, the formation of biomolecular condensates appears to be a fundamental step that not only promotes the self-assembly of a pericentriolar architecture but also triggers the process of centriole duplication.

中心体是一种独特的无膜多蛋白细胞器，是动物细胞中主要的微管组织中心，在细胞周期的有序进行中起着关键作用。由于中心体的错误组装和复制导致细胞分裂异常，从而导致各种人类疾病，阐明中心体组装和功能的分子机制可能是理解中心体相关人类疾病病因的关键一步。通过将细胞生物学与生物物理方法和X射线晶体学相结合，我们证明了两种中心粒周围支架Cep 152和Cep 63具有共相分离成凝聚物的内在活性，并形成异四聚体复合物，该复合物可作为构建模块。围绕中心粒产生纳米级圆柱形自组装。值得注意的是，两个名为自组装基序（分别来自Cep 63和Cep 152）的短的未表征区域合作赋予了物理化学性质，使它们能够经历密度转变并自组装成圆柱形结构。有趣的是，Cep 152-Cep 63凝聚物表现出快速的周转，与其他组件融合，并在凝聚物内进行了显着程度的内部重排。一个Cep 152-Cep 63的圆柱形架构，自组装在一个平面基板上显示出减少，但仍然可检测到的动态营业额水平。有趣的是，Polo样激酶4（Plk 4），中心粒生物发生的关键调节因子，也从中心粒周围的Cep 152结合状态动态地相分离（即，环状态）转变成点状的、低纳米级的球形凝聚物（即，点状态），使其C-末端隐蔽polo-box结构域自磷酸化。另外的体外和体内数据表明，Plk 4缩合物通过积累下游原中心粒组装组分如STIL和Sas 6并促进Plk 4介导的中心粒生物发生而在未来的原中心粒组装位点充当组装体。因此，生物分子凝聚物的形成似乎是一个基本的步骤，不仅促进了自组装的pericentriolar架构，但也触发了中心粒复制的过程。