FIGURE 2.

SIRT3 opposes hyperacetylation of its targets under CR during aging. (a–d) Liver mitochondrial acetylome analysis using stoichiometry‐based MS quantification. See Table S2 for all identified acetyl‐lysine sites and statistical analysis, n = 4 per group. (a) Percentage of significantly changed acetyl‐lysine residues that show increased stoichiometry due to Sirt3^−/− status, calculated by (the number of acetyl‐lysine sites showing increased stoichiometry)/(the number of significantly changed acetyl‐lysine sites, p < 0.05 ×100%. 5: 5 months old; 25: 25 months old. (b) Heat map of significantly changed lysine sites p < 0.05 in 25 month‐old mice that are a response to loss of SIRT3. Plotted sites are significantly changed (p < 0.1) in either Sirt3^−/−CD versus WTCD or Sirt3^−/−CR versus WTCR comparison. Values are colored based on relative acetylation stoichiometry, normalized to the median value of each site in all four groups, scaling ranging from ‐0.8 to 0.8 (×100%). (c) Functional cluster analysis of KEGG pathways (DAVID 6.8). Significantly enriched (−log10(p value) >1.5) pathways are indicated, with 25 month‐old Sirt3^−/−CD versus WTCD in orange and 25 month‐old Sirt3^−/−CR versus WTCR in blue. (d) Acetylation sites in FAO and BACC metabolism, TCA cycle, and ETC that displayed larger than 5% stoichiometry (p < 0.1) for 25 month‐old Sirt3^−/−CD versus WTCD (orange colored) and 25 month‐old Sirt3^−/−CR versus WTCR comparison (blue colored). CD, control diet; CR, calorie restriction; MS, mass spectrometry; SIRT3, sirtuin3