Replacement of the promoter of the yeast plasma membrane ATPase gene by a galactose-dependent promoter and its physiological consequences.

In order to probe the physiological role of the yeast plasma membrane ATPase we have replaced the constitutive promoter of its gene by a galactose-dependent promoter. The resulting cells stop growing on glucose medium when the preformed ATPase is diluted to 20% of normal. There is a correlation between ATPase activity and both proton efflux from the cells and amino acid transport. A large proportion of growth-arrested cells appear enlarged and with several buds containing nuclei.