Raymond C K, Howald-Stevenson I, Vater C A, Stevens T H
Institute of Molecular Biology, University of Oregon, Eugene 97403.
Mol Biol Cell. 1992 Dec;3(12):1389-402. doi: 10.1091/mbc.3.12.1389.
The collection of vacuolar protein sorting mutants (vps mutants) in Saccharomyces cerevisiae comprises of 41 complementation groups. The vacuoles in these mutant strains were examined using immunofluorescence microscopy. Most of the vps mutants were found to possess vacuolar morphologies that differed significantly from wild-type vacuoles. Furthermore, mutants representing independent vps complementation groups were found to share aberrant morphological features. Six distinct classes of vacuolar morphology were observed. Mutants from eight vps complementation groups were defective both for vacuolar segregation from mother cells into developing buds and for acidification of the vacuole. Another group of mutants, represented by 13 complementation groups, accumulated a novel organelle distinct from the vacuole that contained a late-Golgi protein, active vacuolar H(+)-ATPase complex, and soluble vacuolar hydrolases. We suggest that this organelle may represent an exaggerated endosome-like compartment. None of the vps mutants appeared to mislocalize significant amounts of the vacuolar membrane protein alkaline phosphatase. Quantitative immunoprecipitations of the soluble vacuolar hydrolase carboxypeptidase Y (CPY) were performed to determine the extent of the sorting defect in each vps mutant. A good correlation between morphological phenotype and the extent of the CPY sorting defect was observed.
酿酒酵母中液泡蛋白分选突变体（vps突变体）的集合由41个互补群组成。使用免疫荧光显微镜检查了这些突变菌株中的液泡。发现大多数vps突变体具有与野生型液泡明显不同的液泡形态。此外，发现代表独立vps互补群的突变体具有异常的形态特征。观察到六种不同类型的液泡形态。来自八个vps互补群的突变体在液泡从母细胞分离到发育中的芽以及液泡酸化方面均存在缺陷。另一组由13个互补群代表的突变体积累了一种不同于液泡的新型细胞器，该细胞器含有晚期高尔基体蛋白、活性液泡H(+) - ATP酶复合物和可溶性液泡水解酶。我们认为这种细胞器可能代表一种扩大的内体样区室。没有一个vps突变体似乎使大量的液泡膜蛋白碱性磷酸酶发生错误定位。对可溶性液泡水解酶羧肽酶Y（CPY）进行了定量免疫沉淀，以确定每个vps突变体中分选缺陷的程度。观察到形态表型与CPY分选缺陷程度之间有良好的相关性。
