A putative zinc finger protein, Saccharomyces cerevisiae Vps18p, affects late Golgi functions required for vacuolar protein sorting and efficient alpha-factor prohormone maturation.
A putative zinc finger protein, Saccharomyces cerevisiae Vps18p, affects late Golgi functions required for vacuolar protein sorting and efficient alpha-factor prohormone maturation.
复制标题
一种假定的锌指蛋白，酿酒酵母 Vps18p，影响液泡蛋白分选和有效的 α 因子激素原成熟所需的晚期高尔基体功能。
DOI：
10.1128/mcb.11.12.5813-5824.1991
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发表时间：
1991
影响因子：
5.3
通讯作者：
Emr,SD
中科院分区：
文献类型：
--
作者：
Robinson,JS;Graham,TR;Emr,SD
Saccharomyces cerevisiaestrains carryingvps18mutations are defective in the sorting and transport of vacuolar enzymes. The precursor forms of these proteins are missorted and secreted from the mutant cells. Mostvps18mutants are temperature sensitive for growth and are defective in vacuole biogenesis; no structure resembling a normal vacuole is seen. A plasmid complementing the temperature-sensitive growth defect of strains carrying thevps18-4allele was isolated from a centromere-based yeast genomic library. Integrative mapping experiments indicated that the 26-kb insert in this plasmid was derived from theVPS18locus. A 4-kb minimal complementing fragment contains a single long open reading frame predicted to encode a 918-amino-acid hydrophilic protein. Comparison of theVPS18sequence with thePEP3sequence reported in the accompanying paper (R. A. Preston, H. F. Manolson, K. Becherer, E. Weidenhammer, D. Kirkpatrick, R. Wright, and E. W. Jones, Mol. CeU. Biol. 11:5801-5812, 1991) shows that the two genes are identical. Disruption of theVPS18/PEP3gene (vpsl8∆::TRP1) is not lethal but results in the same vacuolar protein sorting and growth defects exhibited by the original temperature-sensitivevps18alleles. In addition,vps18∆1::TRP1 MATα strains exhibit a defect in the Kex2p-dependent processing of the secreted pheromone α-factor. This finding suggests thatvpsl8mutations alter the function of a late Golgi compartment which contains Kex2p and in which vacuolar proteins are thought to be sorted from proteins destined for the cell surface. The Vpsl8p sequence contains a cysteine-rich, zinc finger-like motif at the COOH terminus. A mutant in which the first cysteine of this motif was changed to serine results in a temperature-conditional carboxypeptidase Y sorting defect shortly after a shift to nonpermissive conditions. We identified a similar cysteine-rich motif near the COOH terminus of another Vps protein, the Vps11/Pep5/End1 protein. Preston et al. (Mol. Cell. Biol. 11:5801-5812, 1991) present evidence that the Vpsl8/Pep3 protein colocalizes with the Vps11/Pep5 protein to the cytosolic face of the vacuolar membrane. Together with the similar phenotypes exhibited by bothvps11andvps18mutants, this finding suggests that they may function at a common step during vacuolar protein sorting and that the integrity of their zinc finger motifs may be required for this function.
