Lithium and sodium tolerance in yeast without functional vacuolar H+ ATPase. Strains RS-1175 (ENA1-4 TFP1), RS-1176 (ENA1-4 TFP1 nhaA), RS-1177 (ENA1-4 tfp1), and RS-1178 (ENA1-4 tfp1 nhaA) (top) and strains RS-1170 (ena1-4 TFP1), RS-1171 (ena1-4 TFP1 nhaA), RS-1179 (ena1-4 tfp1), and RS-1180 (ena1-4 tfp1 nhaA) (bottom) were tested for salt tolerance as described in Materials and Methods. Plates contained either no salt (control) or 0.2 M LiCl, 0.4 M NaCl, or 1.2 M NaCl as indicated. Similar results were obtained in three independent experiments.