Protein degradation, meiosis and sporulation in proteinase-deficient mutants of Saccharomyces cerevisiae.
Protein degradation, meiosis and sporulation in proteinase-deficient mutants of Saccharomyces cerevisiae.
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酿酒酵母蛋白酶缺陷突变体的蛋白质降解、减数分裂和孢子形成。
DOI：
10.1093/genetics/97.1.45
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发表时间：
1981
期刊：
影响因子：
3.3
通讯作者：
Jones,EW
中科院分区：
文献类型：
--
作者：
Zubenko,GS;Jones,EW
在产孢过程中，a/α二倍体降解约50%的营养蛋白。这种降解不是孢子形成特异性的，因为a/amating型的无孢子二倍体以类似于ira/α对应物的方式降解其营养蛋白。缺乏羧肽酶Y活性的二倍体，prc 1/prc 1，显示约80%的野生型蛋白质降解水平，但在正常子囊的生产中未受损。缺乏蛋白酶B活性的二倍体，prb 1/prb 1，显示约50%的野生型蛋白质降解水平。蛋白酶B缺乏对降解的影响上位于羧肽酶Y缺乏引起的降解缺陷。prb 1纯合子进行减数分裂并产生孢子，但子囊和孢子可能是异常的。当暴露于孢子形成方案时，对于多效性肽4 - 3突变纯合的二倍体仅显示出野生型水平的30%的降解，并且不经历减数分裂或孢子形成。孢子萌发不需要蛋白酶B和羧肽酶Y。--从暴露于孢子形成方案的a/a或α/α二倍体中产生的表达最初杂合的耐药标记（can 1）的菌落中，约有一半似乎来自交配型转换，随后是减数分裂和孢子形成。
During the process of sporulation,a/α diploids degrade about 50% of their vegetative proteins. This degradation is not sporulation specific, for asporogenous diploids ofa/amating type degrade their vegetative proteins in a fashion similar to that of theira/α counterparts. Diploids lacking carboxypeptidase Y activity,prc1/prc1, show about 80% of wild-type levels of protein degradation, but are unimpaired in the production of normal asci. Diploids lacking proteinase B activity,prb1/prb1, show about 50% of wild-type levels of protein degradation. The effect on degradation of the proteinase B deficiency is epistatic to the degradation deficit attributable to the carboxypeptidase Y deficiency. Theprb1homozygotes undergo meiosis and produce spores, but the asci and, possibly, the spores are abnormal. Diploids homozygous for the pleiotropicpep4-3mutation show only 30% of the wild-type levels of degradation when exposed to a sporulation regimen, and do not undergo meiosis or sporulation. Neither proteinase B nor carboxypeptidase Y is necessary for germination of spores. ——Approximately half of the colonies arising froma/aor α/α diploids exposed to the sporulation regiment that express an initially heterozygous drug-resistance marker (can1) appear to arise from mating-type switches followed by meiosis and sporulation.