ISOLATION OF THE PUTATIVE STRUCTURAL GENE FOR THE LYSINE-ARGININE-CLEAVING ENDOPEPTIDASE REQUIRED FOR PROCESSING OF YEAST PREPRO-ALPHA-FACTOR
ISOLATION OF THE PUTATIVE STRUCTURAL GENE FOR THE LYSINE-ARGININE-CLEAVING ENDOPEPTIDASE REQUIRED FOR PROCESSING OF YEAST PREPRO-ALPHA-FACTOR
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DOI：
10.1016/0092-8674(84)90442-2
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发表时间：
1984-01-01
期刊：
影响因子：
64.5
通讯作者：
THORNER, J
中科院分区：
文献类型：
--
作者：
JULIUS, D;BRAKE, A;THORNER, J
S.酿酒酵母kex 2突变体在产生2种生物活性分泌肽方面是有缺陷的：杀伤毒素和交配信息素，α-因子这两种分子都是从较大的前体多肽中切除的。在正常细胞中，因子前体被核心糖基化并在细胞内被蛋白水解加工。然而，在kex 2突变体中，前原-α-因子不被蛋白水解切割，并且以高度糖基化的形式分泌。所有的kex 2突变体检查（3个独立的等位基因）缺乏一个锌++敏感的膜相关的内肽酶与特异性切割的一对碱性残基的羧基侧。这种活性的缺乏与遗传杂交中kex 2病变的其他表型共分离。正常的KEX 2基因是通过互补kex 2 -1突变所赋予的3种表型而分离的。在多拷贝质粒上或整合到基因组中的克隆的DNA恢复体外酶活性和前原-α-淀粉酶的蛋白水解加工和糖基化的正常模式。体内因素。基因剂量效应表明，KEX 2是内肽酶的结构基因。
S. cerevisiae kex2 mutants are defective for the production of 2 biologically active secreted peptides: killer toxin and the mating pheromone, .alpha.-factor. Both molecules are excised from larger precursor polypeptides. In normal cell, the .alpha.-factor precursor is core-glycosylated and proteolytically processed intracellularly. In kex2 mutants, however, prepro-.alpha.-factor is not proteolytically cleaved and is secreted in a highly glycosylated form. All kex2 mutants examined (3 independent alleles) lack a Zn++-sensitive membrane-associated endopeptidase with specificity for cleaving on the carboxyl side of a pair of basic residues. Absence of this activity cosegregates with the other phenotypes of a kex2 lesion in genetic crosses. The normal KEX2 gene was isolated by complementation of 3 of the phenotypes conferred by the kex2-1 mutation. The cloned DNA, either on a multicopy plasmid or integrated into the genome, restores both enzymatic activity in vitro and the normal pattern of proteolytic processing and glycosylation of prepro-.alpha.-factor in vivo. Gene dosage effects suggest that KEX2 is the structural gene for the endopeptidase.