Differential localization of coatomer complex isoforms within the Golgi apparatus
Differential localization of coatomer complex isoforms within the Golgi apparatus
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DOI：
10.1073/pnas.0611360104
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发表时间：
2007-03-13
影响因子：
11.1
通讯作者：
Wieland, Felix T.
中科院分区：
文献类型：
--
作者：
Moelleken, Joerg;Malsam, Joerg;Wieland, Felix T.
Coatomer是包衣蛋白复合物（COP）l-囊泡的包衣蛋白，是由α -、β -、β '-、γ -、δ -、ε -和ζ -COP 7个亚基组成的可溶性蛋白质复合物。高等真核生物有两个相似的γ -亚基和ζ -亚基，称为γ 1-和γ 2-COP以及ζ 1-和ζ 2-COP。已知这些亚基的不同组合存在于涂层复合物中，gamma 1/zeta 1-， gamma 1/zeta 2-和gamma 2/zeta 1- cop代表了哺乳动物中主要的涂层群体。COPI囊泡在早期分泌途径中的作用是相当有争议的主题。为了帮助解决这一讨论，我们使用了定量免疫电子显微镜，发现copi -异构体的定位确实存在显著差异，早期高尔基体偏爱gamma 1 zeta 1-和gamma 1 zeta 2-涂层体，晚期高尔基体偏爱gamma 2 zeta 1-涂层体。这些差异表明，涂层异构体的不同功能类似于网格蛋白/接头囊泡，其中不同的接头蛋白服务于特定的运输路线。
Coatomer, the coat protein of coat protein complex (COP)l-vesicles, is a soluble protein complex made up of seven subunits, alpha-, beta-, beta'-, gamma-, delta-, epsilon-, and zeta-COP. Higher eukaryotes have two paralogous versions of the gamma- and zeta- subunits, termed gamma 1- and gamma 2-COP and zeta 1- and zeta 2-COP. Different combinations of these subunits are known to exist within coatomer complexes, and gamma 1/zeta 1-, gamma 1/zeta 2-, and gamma 2/zeta 1-COP represent the major coatomer populations in mammals. The role of COPI vesicles in the early secretory pathway is the subject of considerable debate. To help to resolve this discussion, we used quantitative immunoelectron microscopy and found that significant localization differences for COPI-isoforms do exist, with a preference for gamma 1 zeta 1- and gamma 1 zeta 2-coatomer in the early Golgi apparatus and gamma 2 zeta 1-coatomer in the late Golgi apparatus. These differences suggest distinct functions for coatomer isoforms in a manner similar to clathrin/adaptor vesicles, where different adaptor proteins serve particular transport routes.