Amino acid analysis of Saccharomyces cerevisiae cells indicated that neutral amino acids such as glycine and alanine were probably excluded from the vacuoles, and that vacuolar H+-ATPase (V-ATPase) was involved in the vacuolar compartmentalization of these amino acids. We found that vacuolar membrane vesicles export neutral amino acids in an ATP-dependent manner. This is important in identifying vacuolar transporters for neutral amino acids.
