YEAST SYNAPTOBREVIN HOMOLOGS ARE MODIFIED POSTTRANSLATIONALLY BY THE ADDITION OF PALMITATE
YEAST SYNAPTOBREVIN HOMOLOGS ARE MODIFIED POSTTRANSLATIONALLY BY THE ADDITION OF PALMITATE
复制标题
DOI：
10.1073/pnas.92.13.5987
复制
发表时间：
1995-06-20
影响因子：
11.1
通讯作者：
GERST, JE
中科院分区：
文献类型：
--
作者：
COUVE, A;PROTOPOPOV, V;GERST, JE
酵母具有两个同源的突触brevin家族的囊泡相关膜蛋白，在膜识别和囊泡融合中起作用。酵母蛋白Snc1和Snc2定位于分泌囊泡，是构成性胞吐所必需的。它们还与质膜蛋白Sec9形成物理复合物，这是囊泡对接和融合在体内发生所必需的。这种分子复合物的形成，作为囊泡融合的先决条件，似乎在进化上是保守的。在这里，我们证明了Snc蛋白在Snc1的Cys-95上添加棕榈酸酯片段进行了一次翻译后修饰。Cys-95（位于跨膜结构域的近端）的修饰是快速的，发生在内质网中，并且是持久的。Cys-95向Ser-95的突变阻断了棕榈酰化，似乎影响了Snc蛋白的稳定性。这提供了突触蛋白样蛋白在翻译后被修饰的证据，我们预测脂肪酰化可能在高等真核生物中发现。
Yeast possess two homologs of the synaptobrevin family of vesicle-associated membrane proteins that function in membrane recognition and vesicle fusion. Yeast proteins Snc1 and Snc2 localize to secretory vesicles and are required for constitutive exocytosis. They also form a physical complex with a plasma membrane protein, Sec9, which is necessary for vesicle docking and fusion to occur in vivo. Formation of this molecular complex, as a prerequisite for vesicle fusion, appears to have been conserved evolutionarily. Here we demonstrate that Snc proteins undergo a single posttranslational modification with the addition of a palmitate moiety to Cys-95 in Snc1. Modification of Cys-95 (which is located proximal to the transmembrane domain) is rapid, occurs in the endoplasmic reticulum, and is long-lasting. Mutation of Cys-95 to Ser-95 blocks palmitoylation and appears to affect Snc protein stability. This provides evidence that synaptobrevin like proteins are modified posttranslationally, and we predict that fatty acylation may be common to those found in higher eukaryotes.