Nikawa J, Nakano H, Ohi N
Department of Biochemical Engineering and Science, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, Fukuoka, Japan.
Gene. 1996 May 24;171(1):107-11. doi: 10.1016/0378-1119(96)00073-x.
The Saccharomyces cerevisiae ire15 mutant has a defect in the expression of the IN01 gene, showing an inositol auxotrophic phenotype. The growth defect of this mutant is suppressed by human cDNAs such as for the TGF-beta receptor-encoding gene (TGFR) [Nikawa, Gene 149 (1994) 367-372]. Here, we isolated a new human cDNA, HCP1, which suppresses the ire15 mutation by genetic complementation. Sequencing analysis revealed that HCP1 encodes 360 amino acid residues (40,515 Da). The product of HCP1 is highly conserved among species and the yeast homolog was also found to suppress the ire15 mutation. Northern blot analysis revealed that multicopies of the yeast and human HCP1, as well as TGFR, resulted in an increase in the IN01 mRNA level in the yeast mutant. These results clearly indicate that the products of human and yeast HCP1 are structural and functional homologs, and are involved in expression of genes such as of IN01.
酿酒酵母ire15突变体在IN01基因的表达上存在缺陷，表现出肌醇营养缺陷型表型。该突变体的生长缺陷可被诸如转化生长因子β受体编码基因（TGFR）等人类cDNA所抑制[西川，《基因》149（1994）367 - 372]。在此，我们分离出一种新的人类cDNA，即HCP1，它通过基因互补抑制ire15突变。序列分析表明，HCP1编码360个氨基酸残基（40,515道尔顿）。HCP1的产物在物种间高度保守，并且发现其酵母同源物也能抑制ire15突变。Northern印迹分析显示，酵母和人类HCP1以及TGFR的多拷贝导致酵母突变体中IN01 mRNA水平升高。这些结果清楚地表明，人类和酵母HCP1的产物是结构和功能上的同源物，并参与诸如IN01等基因的表达。
