Figure 2. Potassium restriction extends yeast lifespan in a vacuole-dependent manner.
In each trace, the y-axis reports the proportion of yeast mother cells that produced at least the number of daughter cells on the x; the number in parentheses reports the median lifespan, in number of divisions, across biological replicates of the indicated genotype in standard medium (control) and/or treatment. Confidence intervals for lifespan measurements are reported in Table S2. (A) Wild-type cells cultured in the indicated medium. Control, standard medium; low-K, potassium restricted medium. (B) Strains isogenic to wild-type lacking the indicated potassium transporter. (C) Wild-type cells cultured in the indicated medium; 2XK, control medium with twice the potassium concentration of the standard; SPS, medium supplemented with 5 mM sodium polystyrene sulfonate. The impact of potassium restriction was significantly different between standard and 2XK media (p = 0.024). (D) vph1, a strain isogenic to the wild-type lacking VPH1, a component of the vacuolar H+ ATPase. The impact of potassium restriction was significantly different between wild-type and vph1 (p = 0.026). (E) AVT1OE, a strain isogenic to the wild-type overexpressing the vacuolar amino acid transporter AVT1. The impact of potassium restriction was significantly different between wild-type and AVT1OE (p= 9.5×10−5). (F) avt1, a strain isogenic to the wild-type lacking AVT1. The impact of potassium restriction was significantly different between wild-type and AVT1OE (p = 9.7×10−14). *, p < 0.001 in a comparison to wild-type in control medium. #, p < 0.001 in a comparison to avt1 in control medium.