Vallejo C G, Serrano R
European Molecular Biology Laboratory, Heidelberg, Germany.
Yeast. 1989 Jul-Aug;5(4):307-19. doi: 10.1002/yea.320050411.
Two mutations containing insertions and deletions in the promoter in the plasma membrane H+-ATPase gene (PMA1) of Saccharomyces cerevisiae have been introduced into the genome by homologous recombination, replacing the wild-type gene. The resulting strains have 15 and 23% of the wild-type ATPase content. Decreased levels of ATPase correlate with decreased rates of proton efflux and decreased uptake rates of amino acids, methylamine, hygromycin B and tetraphenylphosphonium. This supports a central role of the enzyme in yeast bioenergetics. However, the final accumulation gradient of tetraphenylphosphonium is not affected by the mutations and that of methylamine and 2-aminoisobutyric acid is only decreased in the most extreme mutant. Apparently, kinetic constraints seem to prevent the equilibration of yeast active transports with the electrochemical proton gradient. As expected from their transport defects, the ATPase-deficient mutants are more resistant to hygromycin B and more sensitive to acidification than wild-type yeast. Mutant cells are very elongated, suggesting a structural role of the ATPase in the yeast surface.
通过同源重组将酿酒酵母质膜H⁺-ATP酶基因（PMA1）启动子中含有插入和缺失的两个突变引入基因组，取代野生型基因。所得菌株的ATP酶含量分别为野生型的15%和23%。ATP酶水平的降低与质子外流速率降低以及氨基酸、甲胺、潮霉素B和四苯基鏻的摄取速率降低相关。这支持了该酶在酵母生物能量学中的核心作用。然而，四苯基鏻的最终积累梯度不受突变影响，甲胺和2-氨基异丁酸的积累梯度仅在最极端的突变体中降低。显然，动力学限制似乎阻止了酵母主动运输与电化学质子梯度的平衡。正如从它们的运输缺陷所预期的那样，ATP酶缺陷型突变体比野生型酵母对潮霉素B更具抗性，对酸化更敏感。突变细胞非常细长，表明ATP酶在酵母表面具有结构作用。
