在酵母中，COP I和COP II包被囊泡直接从内质网出芽形成。

COPI- and COPII-coated vesicles bud directly from the endoplasmic reticulum in yeast.

作者信息

Bednarek S Y, Ravazzola M, Hosobuchi M, Amherdt M, Perrelet A, Schekman R, Orci L

机构信息

Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley 94720, USA.

出版信息

Cell. 1995 Dec 29;83(7):1183-96. doi: 10.1016/0092-8674(95)90144-2.

DOI:10.1016/0092-8674(95)90144-2

PMID:8548805

Abstract

The cytosolic yeast proteins Sec13p-Sec31p, Sec23p-Sec24p, and the small GTP-binding protein Sar1p generate protein transport vesicles by forming the membrane coat termed COPII. We demonstrate by thin section and immunoelectron microscopy that purified COPII components form transport vesicles directly from the outer membrane of isolated yeast nuclei. Another set of yeast cytosolic proteins, coatomer and Arf1p (COPI), also form coated buds and vesicles from the nuclear envelope. Formation of COPI-coated, but not COPII-coated, buds and vesicles on the nuclear envelope is inhibited by the fungal metabolite brefeldin A. The two vesicle populations are distinct. However, both vesicle types are devoid of endoplasmic reticulum (ER) resident proteins, and each contains targeting proteins necessary for docking at the Golgi complex. Our data suggest that COPI and COPII mediate separate vesicular transport pathways from the ER.

摘要

胞质酵母蛋白Sec13p - Sec31p、Sec23p - Sec24p以及小GTP结合蛋白Sar1p通过形成被称为COPII的膜被来产生蛋白质运输囊泡。我们通过超薄切片和免疫电子显微镜证明，纯化的COPII组分直接从分离的酵母细胞核外膜形成运输囊泡。另一组酵母胞质蛋白，即外被体蛋白和Arf1p（COPI），也从核膜形成被膜小芽和囊泡。真菌代谢产物布雷菲德菌素A可抑制核膜上COPI被膜小芽和囊泡的形成，但不抑制COPII被膜小芽和囊泡的形成。这两种囊泡群体是不同的。然而，这两种囊泡类型都不含内质网（ER）驻留蛋白，并且每种都含有在高尔基体复合体对接所需的靶向蛋白。我们的数据表明，COPI和COPII介导了从内质网出发的不同囊泡运输途径。