转运必需内体分选复合物螺旋纤丝Vps24⁃Vps2的冷冻电镜结构研究  

Cryo⁃EM structure of the ESCRT⁃III Vps24⁃Vps2 filament

作　　者：刘德生 李耀旺 孙珊 LIU Desheng;LI Yaowang;SUN Shan(State Key Laboratory of Membrane Biology,Beijing Frontier Research Center for Biological Structures,School of Life Sciences,Tsinghua University,Beijing 100084;School of Life Sciences,Southern University of Science and Technology,Shenzhen Guangdong 518005,China)

机构地区：[1]膜生物学国家重点实验室,北京生物结构前沿研究中心,清华大学生命科学学院,北京100084 [2]南方科技大学生命科学学院,广东深圳518005

出　　处：《电子显微学报》2025年第1期28-35,共8页Journal of Chinese Electron Microscopy Society

基　　金：国家自然科学基金资助项目(No.92254306)。

摘　　要：转运必需内体分选复合物-Ⅲ(endosomal sorting complex required for transport-Ⅲ,ESCRT-Ⅲ)介导了一系列细胞膜重塑事件,包括多囊体的形成、细胞分裂和病毒释放等。这些过程的关键步骤之一是将ESCRT-Ⅲ蛋白亚基组装成纤丝状结构。在本研究中,作者利用冷冻电镜技术解析了由Vps24和Vps2融合蛋白(Vps24-Vps2)形成的双链螺旋纤丝的结构,分辨率为4.07A。在该结构中,呈伸展构象的Vps24-Vps2单体首先形成反向结合的二聚体,二聚体之间再错位结合形成一股螺旋,两股螺旋互相缠绕最终形成纤丝。该结构为理解ESCRT-Ⅲ丝状结构组装以及解聚过程提供了结构基础。The cellular ESCRT-Ⅲ proteins mediate a variety of membrane remodeling activities events such as multivesicular body biogenesis,midbody abscission during cytokinesis,wound plasma membrane repair,and enveloped virus budding.The assembly of ESCRT-Ⅲ subunits into filament⁃like structures is essential for these processes.In this study,we used Cryo⁃electron microscopy to resolve the structure of a double⁃stranded helical filament formed by a chimeric ESCRT-Ⅲ subunit Vps24-Vps2 from Saccharomyces cerevisiae at a resolution of 4-07Å.In each protofilament,the Vps24-Vps2 monomer is in an extended open conformation and assemble in a misaligned manner.Neighboring Vps24-2 monomers between two protofilaments adopt an inverse arrangement to entangle each other into a filament.Our structure provides a structural basis for understanding the assembly and disassembly of ESCRT-Ⅲ filaments.

关 键 词：转运必需内体分选复合物 ESCRT Vps24 Vps2 冷冻电镜结构 

分 类 号：Q7[生物学—分子生物学] Q71Q244