VPS1P, A MEMBER OF THE DYNAMIN GTPASE FAMILY, IS NECESSARY FOR GOLGI MEMBRANE-PROTEIN RETENTION IN SACCHAROMYCES-CEREVISIAE
VPS1P, A MEMBER OF THE DYNAMIN GTPASE FAMILY, IS NECESSARY FOR GOLGI MEMBRANE-PROTEIN RETENTION IN SACCHAROMYCES-CEREVISIAE
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DOI：
10.1002/j.1460-2075.1993.tb05974.x
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发表时间：
1993-08-01
期刊：
影响因子：
11.4
通讯作者：
PAYNE, GS
中科院分区：
文献类型：
--
作者：
WILSBACH, K;PAYNE, GS
酿酒酵母KEX2编码的内切酶位于高尔基复合体中，参与α因子交配信息素前体的成熟。笼状蛋白重链基因的破坏会导致Kex2p在细胞表面的错误定位，并降低α因子前体的成熟度。基于这些发现，已经设计了一种基因筛查来分离影响Kex2p在高尔基复合体中保留的突变。一个基因座lam1的两个等位基因被分离出来，这导致了α因子前体的低效成熟。在lam1细胞中，Kex2p没有错误地定位到细胞表面，但异常不稳定。通过降低空泡蛋白水解酶活性的Pep4突变，可以恢复正常的稳定性。相反，信息素成熟缺陷不能被Pep4纠正。蔗糖密度梯度离心法分离细胞器表明，Kex2p不保留在lam1细胞的高尔基复合体中。液泡蛋白前体由lam1突变体分泌，揭示了高尔基复合体的另一个分类缺陷。遗传互补表明lam1与VPS1基因是等位基因，VPS1基因编码与动力蛋白相关的GTP酶。这些结果表明，Vps1p对于高尔基体晚期隔室的膜蛋白保留是必需的。
The KEX2-encoded endoprotease of Saccharomyces cerevisiae resides in the Golgi complex where it participates in the maturation of alpha-factor mating pheromone precursor. Clathrin heavy chain gene disruptions cause mislocalization of Kex2p to the cell surface and reduce maturation of the alpha-factor precursor. Based on these findings, a genetic screen has been devised to isolate mutations that affect retention of Kex2p in the Golgi complex. Two alleles of a single genetic locus, lam1 (lowered alpha-factor maturation), have been isolated, which result in inefficient maturation of alpha-factor precursor. In lam1 cells, Kex2p is not mislocalized to the cell surface but is abnormally unstable. Normal stability is restored by the pep4 mutation which reduces the activity of vacuolar proteases. In contrast, the pheromone maturation defect is not corrected by pep4. Organelle fractionation by sucrose density gradient centrifugation shows that Kex2p is not retained in the Golgi complex of lam1 cells. Vacuolar protein precursors are secreted by lam1 mutants, revealing another sorting defect in the Golgi complex. Genetic complementation reveals that lam1 is allelic to the VPS1 gene, which encodes a dynamin-related GTPase. These results indicate that Vps1p is necessary for membrane protein retention in a late Golgi compartment.