SUN蛋白的coiled-coil结构域是其内在动态调控因子  

Coiled-Coil Domains of SUN Proteins as Intrinsic Dynamic Regulators

作　　者：Si Nie Huimin Ke Feng Gao Jinqi Ren Mingzhu Wang Lin Huo Weimin Gong 冯巍[2] 

机构地区：[1]不详 [2]中国科学院生物物理研究所

出　　处：《科学新闻》2017年第4期177-178,共2页Science News

基　　金：国家自然科学基金委项目;科技部973项目的资助.

摘　　要：真核细胞的核膜是由内核膜和外核膜组成的双层膜状结构，其可以分隔细胞核与细胞质，保护细胞核内的遗传物质，并维持细胞正常活动所需的机械特性。进化上高度保守的内核膜SUN蛋白和外核膜KASH蛋白在核膜间隙相互作用，形成了一个跨越核膜并连接细胞骨架与细胞核骨架的分子桥梁，其实现了跨核膜机械力的传递，为细胞核定位、染色体重构以及端粒定位等重要生物学过程提供了结构基础。SUN proteins are the core components of LINC complexes that span across the nuclear envelope for nuclear positioning and migration. SUN proteins contain at least one predicted coiled-coil domain preceding the SUN domain. Here, we found that the two coiled-coil domains (CC1 and CC2) of SUN2 exhibit distinct oligomeric states. CC2 is a monomer in solution. The structure of the CC2-SUN monomer revealed that CC2 unexpectedly folds as a three-helix bundle that interacts with the SUN domain and locks it in an inactive conformation. In contrast, CC1 is a trimer. The structure of the CC1 trimer demonstrated that CC1 is an imperfect coiled coil for the trimerization and activation of the SUN domain. Modulations of CC1 and CC2 dictate different oligomeric states of CC1-CC2-SUN, which is essential for LINC complex formation. Thus, the two coiled-coil domains of SUN2 act as the intrinsic dynamic regulators for controlling the SUN domain activity.

关 键 词：SUN 结构 动态调控 蛋白 因子 真核细胞 细胞骨架 细胞核 

分 类 号：Q510.3[生物学—生物化学]