PEP4 gene of Saccharomyces cerevisiae encodes proteinase A, a vacuolar enzyme required for processing of vacuolar precursors
PEP4 gene of Saccharomyces cerevisiae encodes proteinase A, a vacuolar enzyme required for processing of vacuolar precursors
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DOI：
10.1128/mcb.6.7.2490-2499.1986
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发表时间：
1986-07
影响因子：
5.3
通讯作者：
Gustav;Ammerer;C. Hunter;J. Rothman;G. Saari;L. A. Valls;T. Stevens
中科院分区：
文献类型：
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作者：
Gustav;Ammerer;C. Hunter;J. Rothman;G. Saari;L. A. Valls;T. Stevens
通过使用允许检测异常分泌液泡蛋白的酵母细胞的免疫学筛选程序来克隆酿酒酵母的蛋白酶A结构基因(J.H.Rothman、C.P.Hunter、L.A.Valls和T.H.Stevens，Proc.Natl.Acad.Sci.USA，83：3248-3252，1986)。通过补充 pep4-3 突变，在多拷贝质粒上获得了第二个克隆基因。这两个基因的核苷酸序列被独立测定并发现是相同的。克隆基因的预测氨基酸序列表明，蛋白酶 A 是作为 405 个氨基酸前体合成的，该前体通过蛋白水解转化为 329 个氨基酸的成熟酶。蛋白酶 A 与哺乳动物天冬氨酰蛋白酶（例如胃蛋白酶、肾素和组织蛋白酶 D）表现出显着的同源性。相似性不仅反映了相似的功能，而且还反映了两种蛋白质相似的加工和细胞内靶向机制。克隆的蛋白酶 A 结构基因，即使携带在单拷贝质粒上，也可以补充在 pep4 突变体中观察到的几种液泡水解酶活性的缺陷。基因组拷贝中携带缺失的菌株无法补充相反交配类型的 pep4 突变体。遗传连锁数据表明，克隆的蛋白酶 A 结构基因的整合拷贝映射到 PEP4 基因座。因此，PEP4基因编码液泡天冬氨酰蛋白酶、蛋白酶A，其是许多液泡酶原的体内加工所必需的。
The proteinase A structural gene of Saccharomyces cerevisiae was cloned by using an immunological screening procedure that allows detection of yeast cells which are aberrantly secreting vacuolar proteins (J. H. Rothman, C. P. Hunter, L. A. Valls, and T. H. Stevens, Proc. Natl. Acad. Sci. USA, 83:3248-3252, 1986). A second cloned gene was obtained on a multicopy plasmid by complementation of a pep4-3 mutation. The nucleotide sequences of these two genes were determined independently and were found to be identical. The predicted amino acid sequence of the cloned gene suggests that proteinase A is synthesized as a 405-amino-acid precursor which is proteolytically converted to the 329-amino-acid mature enzyme. Proteinase A shows substantial homology to mammalian aspartyl proteases, such as pepsin, renin, and cathepsin D. The similarities may reflect not only analogous functions but also similar processing and intracellular targeting mechanisms for the two proteins. The cloned proteinase A structural gene, even when it is carried on a single-copy plasmid, complements the deficiency in several vacuolar hydrolase activities that is observed in a pep4 mutant. A strain carrying a deletion in the genomic copy of the gene fails to complement a pep4 mutant of the opposite mating type. Genetic linkage data demonstrate that integrated copies of the cloned proteinase A structural gene map to the PEP4 locus. Thus, the PEP4 gene encodes a vacuolar aspartyl protease, proteinase A, that is required for the in vivo processing of a number of vacuolar zymogens.