Vacuolar Amino Acid Transporter Avt5p Is Responsible for Lithium Uptake in Schizosaccharomyces pombe

Abstract

The fission yeast Schizosaccharomyces pombe was sensitive to salinity; cell growth was stopped by 0.5 M NaCl and by 10 mM LiCl. The avt5⁺ gene encodes a vacuolar transporter with a broad specificity for amino acids. We found that the avt5Δ mutant became highly tolerant of Li⁺ and Na⁺ in growth. Concanamycin A-sensitive Li⁺ uptake as well as cellular Li⁺ content was lower in the avt5 mutant, suggesting a role of Avt5p in cellular uptake of toxic Li⁺.