COPI- and COPII-coated vesicles bud directly from the endoplasmic reticulum in yeast
COPI- and COPII-coated vesicles bud directly from the endoplasmic reticulum in yeast
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DOI：
10.1016/0092-8674(95)90144-2
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发表时间：
1995-12-29
期刊：
影响因子：
64.5
通讯作者：
Orci, L
中科院分区：
文献类型：
--
作者：
Bednarek, SY;Ravazzola, M;Orci, L
胞质酵母蛋白Sec13p-Sec31p、Sec23p-Sec24p和小的GTP结合蛋白Sar1p通过形成称为COPII的膜外壳来产生蛋白质运输小泡。我们通过薄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的外膜形成运输囊泡。另一组酵母胞质蛋白，辅酶A和Arf1p(COPI)，也从核膜形成包被的芽和囊泡。真菌代谢物布雷菲尔丁A抑制了核膜上有COPI涂层但没有COPII涂层的芽和小泡的形成。这两个小泡群体是不同的。然而，这两种类型的囊泡都缺乏内质网(ER)驻留蛋白，每种类型都含有停靠在高尔基复合体上所需的靶向蛋白。我们的数据表明，COPI和COPII介导了内质网中不同的囊泡运输途径。
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.