Banfield D K, Lewis M J, Pelham H R
MRC Laboratory of Molecular Biology, Cambridge, UK.
Nature. 1995 Jun 29;375(6534):806-9. doi: 10.1038/375806a0.
The secretory pathway of eukaryotic cells comprises several distinct membrane-bound compartments which are interconnected by transport vesicles that pinch off from one membrane and fuse with the next. Targeting of these vesicles is mediated in part by interactions between integral membrane proteins on the vesicles and target organelles (soluble NSF attachment protein receptors (SNAREs)), termed v-SNAREs and t-SNAREs, respectively. SNAREs required for endoplasmic reticulum (ER)-Golgi transport and for fusion of vesicles with the plasma membrane are already known. Here we identify two yeast membrane proteins that show genetic interactions with Sed5p, which is the t-SNARE for ER-Golgi traffic. One of these membrane proteins, Sft1p, is structurally similar to the known v-SNAREs and is required for transport from an early to a later Golgi compartment. Our results indicate that a single t-SNARE can control more than one transport step, and provide the first candidate for a SNARE involved in intra-Golgi traffic.
真核细胞的分泌途径由几个不同的膜结合区室组成，这些区室通过运输小泡相互连接，运输小泡从一个膜上脱离并与下一个膜融合。这些小泡的靶向定位部分是由小泡上的整合膜蛋白与靶细胞器（可溶性 NSF 附着蛋白受体（SNAREs））之间的相互作用介导的，分别称为 v-SNAREs 和 t-SNAREs。内质网（ER）-高尔基体运输以及小泡与质膜融合所需的 SNAREs 已经为人所知。在这里，我们鉴定出两种酵母膜蛋白，它们与 Sed5p 表现出遗传相互作用，Sed5p 是 ER-高尔基体运输的 t-SNARE。其中一种膜蛋白 Sft1p，在结构上与已知的 v-SNAREs 相似，是从早期高尔基体区室运输到晚期高尔基体区室所必需的。我们的结果表明，单个 t-SNARE 可以控制多个运输步骤，并为参与高尔基体内部运输的 SNARE 提供了首个候选蛋白。
