Paraan Mohammadreza, Mendez Joshua, Sharum Savanna, Kurtin Danielle, He Huan, Stagg Scott M
Institute of Molecular Biophysics, Florida State University, 91 Chieftan Way, Tallahassee, FL 32306, USA.
Department of Physics, Florida State University, 77 Chieftan Way, Tallahassee, FL 32306, USA.
Sci Adv. 2020 Jul 22;6(30):eaba8397. doi: 10.1126/sciadv.aba8397. eCollection 2020 Jul.
Clathrin-coated vesicles mediate trafficking of proteins and nutrients in the cell and between organelles. Proteins included in the clathrin-coated vesicles (CCVs) category include clathrin heavy chain (CHC), clathrin light chain (CLC), and a variety of adaptor protein complexes. Much is known about the structures of the individual CCV components, but data are lacking about the structures of the fully assembled complexes together with membrane and in complex with cargo. Here, we determined the structures of natively assembled CCVs in a variety of geometries. We show that the adaptor β2 appendages crosslink adjacent CHC β-propellers and that the appendage densities are enriched in CCV hexagonal faces. We resolve how adaptor protein 2 and other associated factors in hexagonal faces form an assembly hub with an extensive web of interactions between neighboring β-propellers and propose a structural model that explains how adaptor binding can direct the formation of pentagonal and hexagonal faces.
网格蛋白包被囊泡介导细胞内以及细胞器之间蛋白质和营养物质的运输。网格蛋白包被囊泡（CCV）类别中包含的蛋白质有网格蛋白重链（CHC）、网格蛋白轻链（CLC）以及多种衔接蛋白复合物。关于单个CCV组件的结构我们了解很多，但对于完全组装好的复合物连同膜以及与货物结合时的结构却缺乏相关数据。在这里，我们确定了多种几何形状下天然组装的CCV的结构。我们发现衔接蛋白β2附属物交联相邻的CHCβ-螺旋桨，并且附属物密度在CCV六边形面上富集。我们解析了六边形面中的衔接蛋白2和其他相关因子如何形成一个组装中心，该中心在相邻β-螺旋桨之间具有广泛的相互作用网络，并提出了一个结构模型，解释了衔接蛋白结合如何指导五边形和六边形面的形成。
