Fig. 8: Level of Ubc9 auto-sumoylation is increased in aged cells.

a, b Immunoblot assay of sumoylated proteins (a) and Ubc9-Flag (b) before and after enrichment for replicatively aged cells; blotting done as in Fig. 5a. Calcofluor stain images of young and old cells are shown on the right in each panel. The number outside of and within the parentheses represents the average number of bud scars (i.e., the replicative age or number of cell divisions) and the number of cells measured for counting, respectively. Scale bar: 5 μm. c, d RLS analysis of WT (W303) (c) and ulp2Δ (d) cells with indicated plasmids on SD - Leu plates, as was done in Fig. 3a. e RLS analysis of the indicated strains on the SD plates supplemented with 2.0% or 0.5% glucose, as in the experiments shown in Fig. 3a. f Quantification of RLS ratio of 0.5% to 2.0% in e and Supplementary Fig. 10. Dot blots represent individual data points obtained from three independent experiments. The error bars represent the SD from three independent experiments. Asterisks indicate statistically significant differences (*P < 0.05, two-tailed Student’s t test). g Schematic diagram depicting the role of Ubc9 auto-sumoylation in longevity.