Voa1p functions in V-ATPase assembly in the yeast endoplasmic reticulum.
Voa1p functions in V-ATPase assembly in the yeast endoplasmic reticulum.
复制标题
Voa1p 在酵母内质网中的 V-ATP 酶组装中发挥作用。
DOI：
10.1091/mbc.e08-06-0629
复制
发表时间：
2008
影响因子：
3.3
通讯作者：
Stevens,TomH
中科院分区：
文献类型：
--
作者：
Ryan,Margret;Graham,LaurieA;Stevens,TomH
酵母无糖酵母ATP酶（Saccharomyces aevacuolar ATPase，V-ATPase）是一个多亚基复合体，分为两个部分：V1部分催化ATP水解，V0部分使质子移位，导致其驻留细胞器酸化。四种蛋白质因子参与V0的组装。我们已经发现了第五个V0装配因子，Voa 1 p（YGR 106 C）;内质网（ER）本地化的膜糖蛋白。Voa 1 p在V0装配中的作用在表达ER修复缺陷形式的V-ATP酶装配因子Vma 21 p（Vma 21 pQQ）的细胞中被揭示。Voa 1 p invma 21 QQ酵母细胞的丧失导致V-ATP酶功能的丧失;细胞不能酸化其空泡，并表现出缺乏V-ATP酶的细胞的典型生长缺陷。V0装配严重受损invoa 1 vma 21 QQ双突变体。V0-Vma 21 p复合物的分离表明，Voa 1 p与Vma 21 p以及V0亚基c、c′和c″的核心蛋白脂质环的结合最强。在剩余的三个V0亚基（a、d和e）组装成V0复合物时，Voa 1 p从现在完全组装的V0-Vma 21 p复合物中解离。我们的研究结果表明，Voa 1 p功能与Vma 21 p早在V0装配在ER，但它解离之前退出的V0-Vma 21 p复合物从ER运输到高尔基室。
The yeastSaccharomyces cerevisiaevacuolar ATPase (V-ATPase) is a multisubunit complex divided into two sectors: the V1sector catalyzes ATP hydrolysis and the V0sector translocates protons, resulting in acidification of its resident organelle. Four protein factors participate in V0assembly. We have discovered a fifth V0assembly factor, Voa1p (YGR106C); an endoplasmic reticulum (ER)-localized integral membrane glycoprotein. The role of Voa1p in V0assembly was revealed in cells expressing an ER retrieval-deficient form of the V-ATPase assembly factor Vma21p (Vma21pQQ). Loss of Voa1p invma21QQyeast cells resulted in loss of V-ATPase function; cells were unable to acidify their vacuoles and exhibited growth defects typical of cells lacking V-ATPase. V0assembly was severely compromised invoa1 vma21QQdouble mutants. Isolation of V0–Vma21p complexes indicated that Voa1p associates most strongly with Vma21p and the core proteolipid ring of V0subunits c, c′, and c″. On assembly of the remaining three V0subunits (a, d, and e) into the V0complex, Voa1p dissociates from the now fully assembled V0–Vma21p complex. Our results suggest Voa1p functions with Vma21p early in V0assembly in the ER, but then it dissociates before exit of the V0–Vma21p complex from the ER for transport to the Golgi compartment.