酵母中肌醇生物合成的调控突变：肌醇分泌突变体的分离
Regulatory mutations of inositol biosynthesis in yeast: isolation of inositol-excreting mutants.
作者信息
Greenberg M L, Reiner B, Henry S A
出版信息
Genetics. 1982 Jan;100(1):19-33. doi: 10.1093/genetics/100.1.19.
The enzyme inositol-1-phosphate synthase (I-1-P synthase), product of the INO1 locus, catalyzes the synthesis of inositol-1-phosphate from the substrate glucose-6-phosphate. The activity of this enzyme is dramatically repressed in the presence of inositol. By selecting for mutants which overproduce and excrete inositol, we have identified mutants constitutive for inositol-1-phosphate synthase as well as a mutation in phospholipid biosynthesis. Genetic analysis of the mutants indicates that at least three loci (designated OPI1, OPI2 and OPI4) direct inositol-mediated repression of I-1-P synthase. Mutants of these loci synthesize I-1-P synthase constitutively. Three loci are unlinked to each other and to INO1, the structural gene for the enzyme. A mutant of a fourth locus, OPI3, does not synthesize I-1-P synthase constitutively, despite its inositol excretion phenotype. This mutant is preliminarily identified as having a defect in phospholipid synthesis.
肌醇-1-磷酸合酶（I-1-P合酶）由INO1基因座编码，催化底物葡萄糖-6-磷酸合成肌醇-1-磷酸。在肌醇存在的情况下，该酶的活性会受到显著抑制。通过筛选过量产生并分泌肌醇的突变体，我们鉴定出了肌醇-1-磷酸合酶组成型突变体以及磷脂生物合成中的一个突变。对这些突变体的遗传分析表明，至少有三个基因座（命名为OPI1、OPI2和OPI4）指导肌醇介导的I-1-P合酶抑制作用。这些基因座的突变体组成型合成I-1-P合酶。这三个基因座彼此不连锁，也与该酶的结构基因INO1不连锁。第四个基因座OPI3的一个突变体尽管具有肌醇排泄表型，但并不组成型合成I-1-P合酶。该突变体初步被鉴定为在磷脂合成方面存在缺陷。
Zotero 插件