Coatomer, the coat protein of COPI transport vesicles, discriminates endoplasmic reticulum residents from p24 proteins
Coatomer, the coat protein of COPI transport vesicles, discriminates endoplasmic reticulum residents from p24 proteins
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DOI：
10.1128/mcb.01055-06
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发表时间：
2006-11-01
影响因子：
5.3
通讯作者：
Wieland, Felix
中科院分区：
文献类型：
--
作者：
Bethune, Julien;Kol, Matthijs;Wieland, Felix
在COPI囊泡的形成过程中，被衣蛋白和膜蛋白之间发生相互作用：要么是用于回收内质网（ER）的货物蛋白，要么是在内质网和高尔基体之间循环的蛋白质。虽然已经确定了ER居民涂层上的结合位点，但循环蛋白如何与COPI涂层结合仍不清楚。为了在分子水平上理解这些蛋白质的摄取机制，我们研究了p24蛋白与涂层的结合，作为循环蛋白和er常驻货物的例子。p24蛋白需要二聚化才能在γ - cop的两个独立结合位点与涂层相互作用。相比之下，er驻留的货物作为单体结合到涂层上，并结合到γ - cop以外的位点上。因此，COPI外壳通过涉及不同亚基的差异结合来区分p24蛋白和er驻留蛋白。
In the formation of COPI vesicles, interactions take place between the coat protein coatomer and membrane proteins: either cargo proteins for retrieval to the endoplasmic reticulum (ER) or proteins that cycle between the ER and the Golgi. While the binding sites on coatomer for ER residents have been characterized, how cycling proteins bind to the COPI coat is still not clear. In order to understand at a molecular level the mechanism of uptake of such proteins, we have investigated the binding to coatomer of p24 proteins as examples of cycling proteins as well as that of ER-resident cargos. The p24 proteins required dimerization to interact with coatomer at two independent binding sites in gamma-COP. In contrast, ER-resident cargos bind to coatomer as monomers and to sites other than gamma-COP. The COPI coat therefore discriminates between p24 proteins and ER-resident proteins by differential binding involving distinct subunits.