Mutations in the guanine nucleotide-binding domains of a yeast G alpha protein confer a constitutive or uninducible state to the pheromone response pathway.
Mutations in the guanine nucleotide-binding domains of a yeast G alpha protein confer a constitutive or uninducible state to the pheromone response pathway.
复制标题
酵母 G α 蛋白的鸟嘌呤核苷酸结合结构域的突变赋予信息素响应途径组成型或不可诱导状态。
DOI：
10.1101/gad.5.3.475
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发表时间：
1991
影响因子：
10.5
通讯作者：
Dietzel,C
中科院分区：
文献类型：
--
作者：
Kurjan,J;Hirsch,JP;Dietzel,C
鸟嘌呤核苷酸结合蛋白的几个结构域是保守的，并形成鸟嘌呤核苷酸结合口袋。EF-Tu、ras和Gas中这些结构域的突变已显示导致信息表型。我们在SCG 1中进行了几个类似的改变，SCG 1编码参与酵母中信息素反应的G蛋白的α亚基。scg 1 Lys 388和scg 1Ala 391突变导致严重的生长和细胞形态缺陷;这种表型类似于无效表型，并且是由信息素反应途径的组成性激活引起的。基于酵母G蛋白作用的模型，这些突变的作用与ras中类似突变的作用一致，这导致转化表型。SCG 1Ala 322突变导致信息素反应和交配缺陷。这种效应类似于类似的G α s突变的效应，其导致腺苷酸环化酶的刺激缺陷。scg 1Val 50突变类似于转化突变rasVal 12，导致多种效应，包括生长、细胞形态和交配缺陷。我们的一些结果和解释与先前发表的SCG 1中相同突变的结果不同;具体而言，我们对该突变的基因替换导致信息素反应途径的高基础激活，与GTdR缺陷一致，这在低拷贝质粒上的scg 1Val 50之前没有看到。讨论了这些表型的含义。
Several domains of guanine nucleotide-binding proteins are conserved and form the guanine nucleotide-binding pocket. Mutations in these domains in EF-Tu, ras, and Gas have been shown to result in informative phenotypes. We made several analogous changes in SCG1, which encodes the alpha subunit of the G protein involved in pheromone response in yeast. The scg1Lys388 and scg1Ala391 mutations resulted in severe growth and cell morphology defects; this phenotype is similar to the null phenotype and results from constitutive activation of the pheromone response pathway. On the basis of the model for the action of the yeast G protein, the effect of these mutations is consistent with the effect of analogous mutations in ras, which result in a transforming phenotype. The SCG1Ala322 mutation resulted in pheromone response and mating defects. This effect is similar to the effect of the analogous G alpha s mutation, which results in a defect in stimulation of adenylate cyclase. The scg1Val50 mutation, which is analogous to the transforming mutation rasVal12, resulted in multiple effects, including defects in growth, cell morphology, and mating. Some of our results and interpretations are different from previously published results of others for the same mutation in SCG1; specifically, our gene replacement of this mutation resulted in high basal activation of the pheromone response pathway, consistent with a GTPase defect, which was not seen previously with scg1Val50 on a low-copy plasmid. Implications of these phenotypes are discussed.