Umemoto N, Ohya Y, Anraku Y
Department of Biology, Faculty of Science, University of Tokyo, Japan.
J Biol Chem. 1991 Dec 25;266(36):24526-32.
A gene, VMA11, is indispensable for expression of the vacuolar membrane H(+)-ATPase activity in the yeast Saccharomyces cerevisiae (Ohya, Y., Umemoto, N., Tanida, I., Ohta, A., Iida, H., and Anraku, Y. (1991) J. Biol. Chem. 266, 13971-13977). The VMA11 gene was isolated from a yeast genomic DNA library by complementation of the vma11 mutation. The nucleotide sequence of the gene predicts a hydrophobic proteolipid of 164 amino acids with a calculated molecular mass of 17,037 daltons. The deduced amino acid sequence shows 56.7% identity, and significant coincidence in amino acid composition with the 16-kDa subunit c (a VMA3 gene product) of the yeast vacuolar membrane H(+)-ATPase. VMA11 and VMA3 on a multicopy plasmid did not suppress the vma3 and vma11 mutation, respectively, suggesting functional independence of the two gene products. Biochemical detection of the VMA11 gene product was unsuccessful, but vacuoles in the VMA11-disrupted cells were not assembled with either subunit c or subunits a and b of the H(+)-ATPase, resulting in defects of the activity and in vivo vacuolar acidification.
基因VMA11对于酿酒酵母液泡膜H(+) -ATP酶活性的表达不可或缺（Ohya, Y., Umemoto, N., Tanida, I., Ohta, A., Iida, H., and Anraku, Y. (1991) J. Biol. Chem. 266, 13971 - 13977）。通过对vma11突变的互补作用，从酵母基因组DNA文库中分离出VMA11基因。该基因的核苷酸序列预测出一个由164个氨基酸组成的疏水蛋白脂质，计算分子量为17,037道尔顿。推导的氨基酸序列显示与酵母液泡膜H(+) -ATP酶的16-kDa亚基c（VMA3基因产物）有56.7%的同一性，并且在氨基酸组成上有显著的一致性。多拷贝质粒上的VMA11和VMA3分别不能抑制vma3和vma11突变，这表明这两种基因产物在功能上是独立的。对VMA11基因产物的生化检测未成功，但VMA11缺失细胞中的液泡没有与H(+) -ATP酶的亚基c或亚基a和b组装在一起，导致活性缺陷和体内液泡酸化异常。
