Coatomer, Arf1p, and nucleotide are required to bud coat protein complex I-coated vesicles from large synthetic liposomes
Coatomer, Arf1p, and nucleotide are required to bud coat protein complex I-coated vesicles from large synthetic liposomes
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DOI：
10.1073/pnas.95.19.11199
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发表时间：
1998-09-15
影响因子：
11.1
通讯作者：
Orci, L
中科院分区：
文献类型：
--
作者：
Spang, A;Matsuoka, K;Orci, L
合成的外壳蛋白复合物I（COPI）包被的囊泡由大的（直径约300 nm）化学成分确定的脂质体自发形成，脂质体与coatomer、Arf 1 p和鸟苷5 '-[γ-硫代]三磷酸一起孵育。包被囊泡的直径为40-70 nm，大约是由天然膜形成的COPI囊泡的大小。COPI包被的芽和囊泡的形成以及Arf 1 p与供体脂质体的结合依赖于鸟苷5 '-[γ-硫代]三磷酸。与COPII包衣的行为相反，包衣体与含有各种带电或中性磷脂的脂质体结合。然而，COPI芽和囊泡的形成受到酸性磷脂的刺激。在缺乏Arf 1 p的情况下，包衣体与含有二油酰磷脂酸作为唯一酸性磷脂的脂质体结合，以形成大的包衣表面，而不形成COPI包衣的芽或囊泡。我们得出结论，Arf 1 p-GTP和coatomer包括最低限度的必要设备，以创建一个COPI包被囊泡。
Synthetic coat protein complex I (COPI)coated vesicles form spontaneously from large (approximate to 300 nm in diameter), chemically defined liposomes incubated with coatomer, Arf1p, and guanosine 5'-[gamma-thio]triphosphate. Coated vesicles are 40-70 nm in diameter, approximately the size of COPI vesicles formed from native membranes. The formation of COPI-coated buds and vesicles and the binding of Arf1p to donor liposomes depends on guanosine 5'-[gamma-thio]triphosphate. In contrast to the behavior of the COPII coat, coatomer binds to liposomes containing a variety of charged or neutral phospholipids. However, the formation of COPI buds and vesicles is stimulated by acidic phospholipids. In the absence of Arf1p, coatomer binds to liposomes containing dioleoylphosphatidic acid as a sole acidic phospholipid to form large coated surfaces without forming COPI-coated buds or vesicles. We conclude that Arf1p-GTP and coatomer comprise the minimum apparatus necessary to create a COPI-coated vesicle.