The yeast endosomal t-SNARE, pep12p, functions in the absence of its transmembrane domain
The yeast endosomal t-SNARE, pep12p, functions in the absence of its transmembrane domain
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DOI：
10.1034/j.1600-0854.2000.010108.x
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发表时间：
2000-01-01
期刊：
影响因子：
4.5
通讯作者：
Stevens, TH
中科院分区：
文献类型：
--
作者：
Gerrard, SR;Mecklem, AB;Stevens, TH
将蛋白质递送至酿酒酵母的液泡需要两个不同的 SNARE 复合物的功能。 Pep12p 和 Vam3p 都是突触蛋白家族的 t-SNARE，它们是这些 SNARE 复合物的组成部分。我们使用遗传方法来解决 Pep12p 在液泡蛋白运输中的作用，我们对温度敏感的 pep12 突变体的筛选产生了 6 个等位基因，这些等位基因在暴露于不允许的温度时迅速失活。令人惊讶的是，这些等位基因编码的蛋白质在跨膜结构域之前全部被截短。在这里，我们证明 Pep12p 需要其跨膜结构域才能正确定位，但不需要其在囊泡融合中的作用。此外，我们还表明，虽然 Pep12p 可以取代液泡 SNARE 复合物中的 Vam3p，但在此步骤中需要其跨膜结构域才能发挥作用。因此，Pep12p 的跨膜结构域在液泡前和液泡 SNARE 复合体中发挥不同的作用。
Delivery of proteins to the vacuole of the yeast Saccharomyces cerevisiae requires the function of two distinct SNARE complexes. Pep12p and Vam3p are both t-SNAREs of the syntaxin family that are components of these SNARE complexes. We have used a genetic approach to address the role of Pep12p in vacuolar protein transport, Our screen for temperature-sensitive pep12 mutants yielded six alleles that were rapidly inactivated upon exposure to the non-permissive temperature. Surprisingly, the proteins encoded by these alleles were all truncated immediately prior to the transmembrane domain. Here we demonstrate that Pep12p requires its transmembrane domain for proper localization, but not for its role in vesicle fusion, In addition, we show that although Pep12p can replace Vam3p in the vacuolar SNARE complex, its transmembrane domain is required to function at this step. Therefore, the transmembrane domain of Pep12p performs different roles in the prevacuolar and vacuolar SNARE complexes.