Transport of phosphate into vacuoles of Saccharomyces cerevisiae

Isolated vacuoles of the yeast Saccharomyces cerevisiae accumulated orthophosphate at pH 6-7. This accumulation was inhibited by MgATP, and was insensitive to protonophores. Triton X-100 blocked this process. The accumulation increased linear by any phosphate concentrations employed (from 0.2 to 10 mM). It is proposed that phosphate is transported into yeast vacuoles via a channel transport system independent of the electrochemical proton gradient on the vacuolar membrane.