The Structures of COPI-Coated Vesicles Reveal Alternate Coatomer Conformations and Interactions
The Structures of COPI-Coated Vesicles Reveal Alternate Coatomer Conformations and Interactions
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DOI：
10.1126/science.1221443
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发表时间：
2012-06-15
期刊：
影响因子：
56.9
通讯作者：
Briggs, John A. G.
中科院分区：
文献类型：
--
作者：
Faini, Marco;Prinz, Simone;Briggs, John A. G.
真核细胞间的转运是由包被囊泡介导的。从酵母到人类，原型蛋白质外壳COPI、COPII和网格蛋白是保守的。在体外组装的COPII和网格蛋白涂层（无膜）的结构研究表明，涂层组件组装规则笼，组件之间具有相同的相互作用。尚未获得包被膜囊泡的详细三维结构。在这里，我们解决了个别COPI包被膜囊泡的结构，通过冷冻电子断层扫描和subtomograms平均在体外重建出芽反应。被观察到的外壳蛋白复合物，coatomer，采取替代构象改变其他coatomer的数量与它相互作用，并形成囊泡的大小和形状可变。这代表了囊泡外壳组装的根本不同的基础。
Transport between compartments of eukaryotic cells is mediated by coated vesicles. The archetypal protein coats COPI, COPII, and clathrin are conserved from yeast to human. Structural studies of COPII and clathrin coats assembled in vitro without membranes suggest that coat components assemble regular cages with the same set of interactions between components. Detailed three-dimensional structures of coated membrane vesicles have not been obtained. Here, we solved the structures of individual COPI-coated membrane vesicles by cryoelectron tomography and subtomogram averaging of in vitro reconstituted budding reactions. The coat protein complex, coatomer, was observed to adopt alternative conformations to change the number of other coatomers with which it interacts and to form vesicles with variable sizes and shapes. This represents a fundamentally different basis for vesicle coat assembly.