Investigation of the mechanisms involved in the assembly of COPI-coated vesicles by cryo-electron microscopy

除了允许生命形式存在之外，细胞膜将真核细胞的内部组织成生物化学上不同的区室，在其中执行特定的细胞功能。蛋白质（货物）在不连续的亚细胞区室之间的运输依赖于多层外壳蛋白复合物（CPC）在细胞膜上的组装和拆卸。迄今为止，已经描述了三种主要类型的囊泡：网格蛋白-、COPI（外壳蛋白复合物I）-和COPII（外壳蛋白复合物II）-包被的囊泡。网格蛋白包被的囊泡从质膜、高尔基体网络（trans-Golgi network，TGN）和内体出芽。COPI包被的囊泡主要从高尔基体运输到内质网（ER）和高尔基体池之间。COPII包被的囊泡从ER运输到高尔基体。网格蛋白和COPII包被的囊泡的结构最近已被公布。虽然这些囊泡似乎共享一些共同的机械设计，但囊泡组装的方式存在显着差异。

In addition to allow life forms to exist, cellular membranes organize the interior of the eukaryotic cell into biochemically distinct compartments in which specific cellular functions are performed. The transport of proteins (cargo) between discontinuous sub-cellular compartments relies on the assembly and disassembly of multilayered coat protein complexes (CPCs) onto cellular membrane. To-date, three major types of vesicles have been described: clathrin-, COPI (coat protein complex I)- and COPII (coat protein complex II)-coated vesicles. Clathrin-coated vesicles bud from the plasma membrane, trans-Golgi network (TGN) and endosomes. COPI-coated vesicles traffic primarily from the Golgi to the endoplasmic reticulum (ER) and between Golgi cisternae. COPII-coated vesicles traffic from the ER to the Golgi. The structures of clathrin and COPII coated vesicles have recently been published. Although these vesicles appear to share some common mechanical designs, there are significant differences in the way the vesicles are assembled.