Figure 2.

The yeast v-ATPase is required for acidity of the vacuolar lumen and full replicative lifespan. (A) RT-PCR RNA expression analyses of vacuolar proton pump subunits (VMA) and a vacuolar fusion factor (YPT7) in replicatively old cells enriched using MEP. Agarose gel electrophoresis of ethidium bromide stained RT-PCR products is shown. Sip18, encoding an osmotic stress protein previously reported to be upregulated in old cells (Lesur and Campbell 2004), served as a control. See Figure S2A for quantification of old:young mRNA ratios. (B) CMAC-Arg fluorescence imaging of isogenic dividing WT and single deletion yeast mutants. Cells were stained, processed, and imaged in parallel. See Figure S2B for CMAC-Arg fluorescence emission spectra of cells shown here. (C) cDCFDA fluorescence imaging of isogenic dividing WT and single deletion yeast mutants. Cells were stained, processed, and imaged in parallel. (D) RLS of WT yeast and deletion mutants on YPD media. Statistical analysis is available in Table S1 in File S1.