Calorie Restriction and SIRT3 Trigger Global Reprogramming of the Mitochondrial Protein Acetylome

SummaryCalorie restriction (CR) extends life span in diverse species. Mitochondria play a key role in CR adaptation; however, the molecular details remain elusive. We developed and applied a quantitative mass spectrometry method to probe the liver mitochondrial acetyl-proteome during CR versus control diet in mice that were wild-type or lacked the protein deacetylase SIRT3. Quantification of 3,285 acetylation sites—2,193 from mitochondrial proteins—rendered a comprehensive atlas of the acetyl-proteome and enabled global site-specific, relative acetyl occupancy measurements between all four experimental conditions. Bioinformatic and biochemical analyses provided additional support for the effects of specific acetylation on mitochondrial protein function. Our results (1) reveal widespread reprogramming of mitochondrial protein acetylation in response to CR and SIRT3, (2) identify three biochemically distinct classes of acetylation sites, and (3) provide evidence that SIRT3 is a prominent regulator in CR adaptation by coordinately deacetylating proteins involved in diverse pathways of metabolism and mitochondrial maintenance.

Graphical AbstractFigure optionsDownload full-size imageDownload high-quality image (420 K)Download as PowerPoint slideHighlights► MS quantifies 1,578 mitochondrial acetyl sites altered during CR and loss of SIRT3 ► SIRT3 functions as a prominent regulator in CR adaptation ► CR and SIRT3 regulate previously unrecognized processes in mitochondria ► We provide an acetylation atlas for understanding mitochondrial regulation in CR