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Updated: May 24, 2026

Deacetylation Assays to Unravel the Interplay between Sirtuins (SIRT2) and Specific Protein-substrates
14:32

Deacetylation Assays to Unravel the Interplay between Sirtuins (SIRT2) and Specific Protein-substrates

Published on: February 27, 2016

SIRT3 protein deacetylates isocitrate dehydrogenase 2 (IDH2) and regulates mitochondrial redox status

Wei Yu1, Kristin E Dittenhafer-Reed, John M Denu

  • 1Department of Biomolecular Chemistry and the Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, Wisconsin 53715, USA.

The Journal of Biological Chemistry
|March 15, 2012
PubMed

Insights

Caloric restriction activates SIRT3 deacetylase, which enhances IDH2 enzyme activity by removing an inhibitory acetyl group. This boosts NADPH production, protecting cells from oxidative stress and potentially impacting cancer metabolism.

Area of Science:

  • Mitochondrial biology
  • Metabolic regulation
  • Oxidative stress

Background:

  • Mitochondria are crucial for energy metabolism and implicated in age-related diseases.
  • NADPH-dependent antioxidant pathways maintain cellular redox balance.
  • Isocitrate dehydrogenase 2 (IDH2) is a key source of mitochondrial NADPH.

Purpose of the Study:

  • To investigate the regulatory relationship between IDH2 and SIRT3 under caloric restriction.
  • To elucidate the mechanism by which SIRT3 influences IDH2 activity.
  • To explore the implications for cellular redox homeostasis and disease.

Main Methods:

  • Biochemical assays to measure IDH2 activity.
  • Site-directed mutagenesis to create acetylated and deacetylated IDH2 variants.
  • Genetic incorporation of acetyllysine at a specific IDH2 residue (Lys-413).
  • Oxidative stress assays in mouse embryonic fibroblasts (MEFs).

Main Results:

  • Acetylation of IDH2 at Lys-413 caused a 44-fold decrease in its activity.
  • SIRT3-mediated deacetylation fully restored IDH2 activity.
  • SIRT3's protection against oxidative stress was IDH2-dependent.
  • A deacetylated IDH2 mimic protected Sirt3(-/-) MEFs from oxidative stress by increasing glutathione levels.

Conclusions:

  • SIRT3 directly regulates IDH2 activity through deacetylation at Lys-413.
  • This SIRT3-IDH2 interaction is critical for maintaining redox balance under caloric restriction.
  • The findings reveal a novel mechanism linking SIRT3, IDH2, and oxidative stress, with potential relevance to cancer metabolism.

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