Using Cryo-EM to Study the Structure of COPII Coats

描述(由申请人提供)： 这项计划的目标是使用冷冻电子显微镜对COPII包被的囊泡进行三维重建。COPII蛋白负责形成囊泡，将蛋白质和脂类从内质网(ER)输送到高尔基体。COPII蛋白由Sar1、Sec23/24和Sec13/31组成。它们在内质网膜上形成一个晶格，将膜内陷成一个球形囊泡。生化实验已经提出了蛋白质相互作用的方式，并导致了许多形成COPII晶格的模型。将用低温电子显微镜研究COPII晶格的结构。对Sar1和Sec23/24的晶体结构进行了解析。将这些结构适合于COPII涂层的重建将有助于确定COPII晶格中的蛋白质间接触以及晶格是如何形成的。此外，这些研究将有助于理解真核蛋白质的运输机制，并可能有助于理解和治疗与运输中断相关的疾病。

DESCRIPTION (provided by applicant): The goal of this proposal is to use cryo-electron microscopy to make three-dimensional reconstructions of COPII coated vesicles. COPII proteins are responsible for forming the vesicles that transport proteins and lipids from the endoplasmic reticulum (ER) to the Golgi apparatus. COPII proteins consist of Sar1, Sec23/24, and Sec13/31. These form a lattice on the ER membrane that invaginates the membrane into a spherical vesicle. Biochemical experiments have suggested ways that the proteins interact and have lead to a number of models for the formation of the COPII lattice. The structure of the COPII lattice will be studied by cryoelectron microscopy. Crystal structures of Sar1 and Sec23/24 have been solved. Fitting these structures into the reconstruction of the COPII coat will help determine the inter-protein contacts in the COPII lattice and how the lattice is formed. Moreover, these studies will contribute to the understanding of eukaryotic protein transport machinery and may contribute to the understanding and treatment of diseases associated with disrupted transport.