A novel SNARE complex implicated in vesicle fusion with the endoplasmic reticulum
A novel SNARE complex implicated in vesicle fusion with the endoplasmic reticulum
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DOI：
10.1093/emboj/16.11.3017
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发表时间：
1997-06-02
期刊：
影响因子：
11.4
通讯作者：
Pelham, HRB
中科院分区：
文献类型：
--
作者：
Lewis, MJ;Rayner, JC;Pelham, HRB
细胞内的囊泡运输部分由v- snares和t-SNAREs控制，这两种完整的膜蛋白允许囊泡（v- snares）与其靶膜（t-SNAREs）之间的特异性相互作用和融合。在酵母中，从高尔基复合体到内质网的逆行运输是由ER t-SNARE Ufe1p介导的，并且还需要另外两种ER蛋白Sec20p和Tip20p相互结合。我们发现它和Tip20p都可以与Ufe1p共沉淀，并且Ufe1p的生长抑制突变可以通过Sec20p的突变来补偿。此外，Sec22p，一个参与从内质膜到高尔基体的前向转运的v-SNARE，与Ufe1p和Sec20p共沉淀，而SEC22作为温度敏感的ufe1突变的等位基因特异性多拷贝抑制因子。这些结果定义了一种新的功能性SNARE复合物，其特征与先前发现的质膜和顺式高尔基复合物不同。他们还表明，单个v-SNARE可以参与顺行和逆行运输，这表明仅存在特定的v-SNARE可能不足以确定运输囊泡的首选目标。
Intracellular vesicular traffic is controlled in part by v- and t-SNAREs, integral membrane proteins which allow specific interaction and fusion between vesicles (v-SNAREs) and their target membranes (t-SNAREs), In yeast, retrograde transport from the Golgi complex to the ER is mediated by the ER t-SNARE Ufe1p, and also requires two other ER proteins, Sec20p and Tip20p, which bind each other, Although Sec2Op is not a typical SNARE, we show that both it and Tip20p can be co-precipitated with Ufe1p, and that a growth-inhibiting mutation in Ufe1p can be compensated by a mutation in Sec20p, Furthermore, Sec22p, a v-SNARE implicated in forward transport from ER to Golgi, co-precipitates with Ufe1p and Sec20p, and SEC22 acts as an allele-specific multicopy suppressor of a temperature-sensitive ufe1 mutation. These results define a new functional SNARE complex, with features distinct from the plasma membrane and cis-Golgi complexes previously identified, They also show that a single v-SNARE can be involved in both anterograde and retrograde transport, which suggests that the mere presence of a particular v-SNARE may not be sufficient to determine the preferred target for a transport vesicle.