SNARE selectivity of the COPII coat
SNARE selectivity of the COPII coat
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DOI：
10.1016/s0092-8674(03)00608-1
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发表时间：
2003-08-22
期刊：
影响因子：
64.5
通讯作者：
Goldberg, J
中科院分区：
文献类型：
--
作者：
Mossessova, E;Bickford, LC;Goldberg, J
COPII外被芽从内质网运输小泡，并将货物和陷阱分子。在这里，我们表明，识别ER-高尔基体陷阱Bet 1，Sed 5和Sec 22发生通过三个结合位点的Sec 23/24亚复合物的酵母COPII。A位点与Sed 5的YNNSNPF基序结合。B位点与存在于Bet 1和Sed 5分子中的Lxx-UM-E序列以及DxE货物分选信号结合。第三个空间上不同的位点与Sec 22结合。COPII选择Bet 1的游离v-SNARE形式，因为LxxLE序列被隔离在v-/t-SNARE复合物的四螺旋束中。COPII有利于Sed 5/Bos 1/Sec 22 t-SNARE复合物中的Sed 5，因为t-SNARE组装去除了自抑制接触以暴露YNNSNPF基序。COPII外套似乎是这些SNARE的融合形式的特定导体，这表明如何囊泡融合特异性可能在出芽过程中编程。
The COPII coat buds transport vesicles from the endoplasmic reticulum that incorporate cargo and SNARE molecules. Here, we show that recognition of the ER-Golgi SNAREs Bet1, Sed5, and Sec22 occurs through three binding sites on the Sec23/24 subcomplex of yeast COPII. The A site binds to the YNNSNPF motif of Sed5. The B site binds to Lxx-UM-E sequences present in both the Bet1 and Sed5 molecules, as well as to the DxE cargo-sorting signal. A third, spatially distinct site binds to Sec22. COPII selects the free v-SNARE form of Bet1 because the LxxLE sequence is sequestered in the four-helix bundle of the v-/t-SNARE complex. COPII favors Sed5 within the Sed5/Bos1/ Sec22 t-SNARE complex because t-SNARE assembly removes autoinhibitory contacts to expose the YNNSNPF motif. The COPII coat seems to be a specific conductor of the fusogenic forms of these SNAREs, suggesting how vesicle fusion specificity may be programmed during budding.