In vivo and in vitro analysis of ptl1, a yeast ts mutant with a membrane-associated defect in protein translocation.
In vivo and in vitro analysis of ptl1, a yeast ts mutant with a membrane-associated defect in protein translocation.
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ptl1 的体内和体外分析，ptl1 是一种酵母 ts 突变体，具有膜相关的蛋白质易位缺陷。
DOI：
10.1002/j.1460-2075.1988.tb03333.x
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Meyer,DI
中科院分区：
文献类型：
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作者：
Toyn,J;Hibbs,AR;Sanz,P;Crowe,J;Meyer,DI
在Trp-Saccharmyces cerevisiae中，根据其将融合蛋白保留在胞浆中的能力，选择了在内质网膜上转运蛋白质能力有缺陷的突变体。融合基因由前α因子前体(MFα1)N端至磷酸核糖基邻氨基苯甲酸异构酶(TRP1)的前体区域组成。第一种蛋白质易位突变称为ptl1，导致生长和蛋白质易位的温度敏感性。在不允许的温度下，几种分泌蛋白的前体在细胞质中积累。利用这个突变体，我们证明了在不允许的温度下积累在胞浆中的前羧基肽酶Y可以在细胞回到允许的温度时翻译后转位到内质网中。这一结果表明，在体内可以发生翻译后前蛋白跨内质网膜的移位。我们还确定了ptl1中的温度敏感成分是膜相关的，并且从该菌株衍生的膜在体外表现出可逆的温度敏感易位表型。
Mutants defective in the ability to translocate proteins across the membrane of the endoplasmic reticulum were selected in Trp‐ Saccharomyces cerevisiae on the basis of their ability to retain a fusion protein in the cytosol. The fusion comprised the prepro region of prepro‐alpha‐factor (MF alpha 1) N‐terminal to phosphoribosyl anthranilate isomerase (TRP1). The first of the protein translocation mutations, called ptl1, results in temperature‐sensitivity of growth and protein translocation. At the non‐permissive temperature, precursors to several secretory proteins accumulate in the cytosol. Using this mutant, we demonstrate that the prepro‐carboxypeptidase Y that had been accumulated in the cytosol at the non‐permissive temperature could be post‐translationally translocated into the endoplasmic reticulum when cells were returned to the permissive temperature. This result indicates that post‐translational translocation of preproteins across endoplasmic reticulum membranes can occur in vivo. We have also determined that the temperature‐sensitive component is membrane‐associated in ptl1, and that the membranes derived from this strain show a reversible temperature‐sensitive translocation phenotype in vitro.