Ma Dandan, Wang Fulin, Wang Rongyi, Hu Yingchun, Chen Zhiquan, Huang Ning, Tian Yonglu, Xia Yuqing, Teng Junlin, Chen Jianguo
Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Beijing, China.
Core Facilities College of Life Sciences, Peking University, Beijing, China.
Elife. 2022 Feb 4;11:e73252. doi: 10.7554/eLife.73252.
The centrosome composed of a pair of centrioles (mother and daughter) and pericentriolar material, and is mainly responsible for microtubule nucleation and anchorage in animal cells. The subdistal appendage (SDA) is a centriolar structure located at the mother centriole's subdistal region, and it functions in microtubule anchorage. However, the molecular composition and detailed structure of the SDA remain largely unknown. Here, we identified α-taxilin and γ-taxilin as new SDA components that form a complex via their coiled-coil domains and that serve as a new subgroup during SDA hierarchical assembly. The taxilins' SDA localization is dependent on ODF2, and α-taxilin recruits CEP170 to the SDA. Functional analyses suggest that α- and γ-taxilin are responsible for SDA structural integrity and centrosomal microtubule anchorage during interphase and for proper spindle orientation during metaphase. Our results shed light on the molecular components and functional understanding of the SDA hierarchical assembly and microtubule organization.
中心体由一对中心粒（母中心粒和子中心粒）及中心粒外周物质组成，主要负责动物细胞中的微管成核和锚定。亚远端附属结构（SDA）是位于母中心粒亚远端区域的一种中心粒结构，其功能是微管锚定。然而，SDA的分子组成和详细结构在很大程度上仍然未知。在这里，我们鉴定出α-微管结合蛋白和γ-微管结合蛋白为新的SDA组分，它们通过其卷曲螺旋结构域形成复合物，并在SDA分级组装过程中作为一个新的亚组发挥作用。微管结合蛋白在SDA的定位依赖于ODF2，并且α-微管结合蛋白将CEP170招募至SDA。功能分析表明，α-微管结合蛋白和γ-微管结合蛋白在间期负责SDA的结构完整性和中心体微管锚定，在中期负责纺锤体的正确定向。我们的结果为SDA分级组装和微管组织的分子组分及功能理解提供了线索。
