Sirtuin 2 regulates cellular iron homeostasis via deacetylation of transcription factor NRF2

J Clin Invest. 2017 Apr 3;127(4):1505-1516. doi: 10.1172/JCI88574. Epub 2017 Mar 13.

Abstract

SIRT2 is a cytoplasmic sirtuin that plays a role in various cellular processes, including tumorigenesis, metabolism, and inflammation. Since these processes require iron, we hypothesized that SIRT2 directly regulates cellular iron homeostasis. Here, we have demonstrated that SIRT2 depletion results in a decrease in cellular iron levels both in vitro and in vivo. Mechanistically, we determined that SIRT2 maintains cellular iron levels by binding to and deacetylating nuclear factor erythroid-derived 2-related factor 2 (NRF2) on lysines 506 and 508, leading to a reduction in total and nuclear NRF2 levels. The reduction in nuclear NRF2 leads to reduced ferroportin 1 (FPN1) expression, which in turn results in decreased cellular iron export. Finally, we observed that Sirt2 deletion reduced cell viability in response to iron deficiency. Moreover, livers from Sirt2-/- mice had decreased iron levels, while this effect was reversed in Sirt2-/- Nrf2-/- double-KO mice. Taken together, our results uncover a link between sirtuin proteins and direct control over cellular iron homeostasis via regulation of NRF2 deacetylation and stability.

MeSH terms

  • Acetylation
  • Animals
  • Cation Transport Proteins / metabolism
  • Epigenesis, Genetic
  • Gene Expression
  • HEK293 Cells
  • Hep G2 Cells
  • Homeostasis
  • Humans
  • Iron / metabolism*
  • Liver / metabolism
  • Mice, Knockout
  • NF-E2-Related Factor 2 / metabolism*
  • Protein Processing, Post-Translational*
  • Protein Stability
  • Sirtuin 2 / physiology*
  • Transcriptional Activation

Substances

  • Cation Transport Proteins
  • NF-E2-Related Factor 2
  • NFE2L2 protein, human
  • metal transporting protein 1
  • Iron
  • SIRT2 protein, human
  • Sirtuin 2