Nikawa J, Murakami A, Esumi E, Hosaka K
Department of Biochemical Engineering and Science, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, Fukuoka.
J Biochem. 1995 Jul;118(1):39-45. doi: 10.1093/oxfordjournals.jbchem.a124889.
Saccharomyces cerevisiae ire15 mutant has a defect in the expression of INO1, showing the inositol auxotrophic phenotype [Nikawa, J. (1994) Gene 149, 367-372]. We have isolated five yeast genes which suppress the ire15 mutation in multiple copies by genetic complementation. Among them, one gene, designated as SCS2, also suppressed the choline-sensitive dominant mutation, CSE1 [Hosaka, K. et al. (1992) J. Biochem. 111, 352-358]. The CSE1 mutation is not allelic to ire15. Sequencing analysis revealed that the SCS2 gene encodes 244 amino acid residues with a calculated molecular mass of 26,866. INO2/SCS1, which is another suppressor gene for CSE1 and is known to be a positive factor for INO1 expression, also suppressed the growth defect of the ire15 mutant. These results clearly indicate that the ire15 and CSE1 mutations genetically interact and the SCS2 and INO2/SCS1 genes are involved in the regulation of INO1 expression.
酿酒酵母ire15突变体在INO1表达上存在缺陷，表现出肌醇营养缺陷型表型[Nikawa, J. (1994) Gene 149, 367 - 372]。我们通过遗传互补分离出了五个能以多拷贝形式抑制ire15突变的酵母基因。其中一个基因，命名为SCS2，也抑制了胆碱敏感显性突变CSE1 [Hosaka, K.等人(1992) J. Biochem. 111, 352 - 358]。CSE1突变与ire15不是等位基因。测序分析表明，SCS2基因编码244个氨基酸残基，计算分子量为26,866。INO2/SCS1是CSE1的另一个抑制基因，已知是INO1表达的正调控因子，它也抑制了ire15突变体的生长缺陷。这些结果清楚地表明，ire15和CSE1突变在遗传上相互作用，并且SCS2和INO2/SCS1基因参与了INO1表达的调控。
