Overexpression of RPI1, a novel inhibitor of the yeast Ras-cyclic AMP pathway, down-regulates normal but not mutationally activated ras function.
Overexpression of RPI1, a novel inhibitor of the yeast Ras-cyclic AMP pathway, down-regulates normal but not mutationally activated ras function.
复制标题
RPI1 是一种新型酵母 Ras 环 AMP 通路抑制剂，其过度表达会下调正常但非突变激活的 ras 功能。
DOI：
10.1128/mcb.11.8.3894-3904.1991
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发表时间：
1991
影响因子：
5.3
通讯作者：
Powers,S
中科院分区：
文献类型：
--
作者：
Kim,JH;Powers,S
A high-copy-number plasmid genomic library was screened for genes that when overexpressed down- regulate Ras protein activity inSaccharomyces cerevisiae. We report on the structure and characterization of one such gene,RPI1, which potentially encodes a novel 46-kDa negative regulator of the Ras-cyclic AMP pathway. Three lines of evidence suggest that theRPI1gene product operates upstream to negatively regulate the activity of normal but not mutationally activated Ras proteins: (i) overexpressedRPI1lowers cyclic AMP levels in wild-type yeast cells but not in yeast cells carrying theRAS2Val-19mutation, (ii) overexpressedRPI1suppresses the heat shock sensitivity phenotype induced by overexpression of normalRAS2but does not suppress the same phenotype induced byRAS2Val-19, and (iii) disruption ofRPI1results in a heat shock sensitivity phenotype which can be suppressed by mutations that lower normal Ras activity. Thus,RPI1appears to encode an inhibitor of Ras activity that shares a common feature with Ras GTPase-activating proteins in that it fails to down-regulate activated RAS2Va1-19function. We present evidence that the down-regulatory effect ofRPI1requires the presence of one of the two Ras GTPase activators,IRA1andIRA2.
