FoxK1 and FoxK2 in insulin regulation of cellular and mitochondrial metabolism

Nat Commun. 2019 Apr 5;10(1):1582. doi: 10.1038/s41467-019-09418-0.

Abstract

A major target of insulin signaling is the FoxO family of Forkhead transcription factors, which translocate from the nucleus to the cytoplasm following insulin-stimulated phosphorylation. Here we show that the Forkhead transcription factors FoxK1 and FoxK2 are also downstream targets of insulin action, but that following insulin stimulation, they translocate from the cytoplasm to nucleus, reciprocal to the translocation of FoxO1. FoxK1/FoxK2 translocation to the nucleus is dependent on the Akt-mTOR pathway, while its localization to the cytoplasm in the basal state is dependent on GSK3. Knockdown of FoxK1 and FoxK2 in liver cells results in upregulation of genes related to apoptosis and down-regulation of genes involved in cell cycle and lipid metabolism. This is associated with decreased cell proliferation and altered mitochondrial fatty acid metabolism. Thus, FoxK1/K2 are reciprocally regulated to FoxO1 following insulin stimulation and play a critical role in the control of apoptosis, metabolism and mitochondrial function.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Cell Proliferation
  • Cell Survival
  • Forkhead Transcription Factors / metabolism
  • Forkhead Transcription Factors / physiology*
  • Glycogen Synthase Kinase 3 / metabolism
  • Humans
  • Insulin / metabolism*
  • Mice
  • Mitochondria / metabolism*
  • Signal Transduction
  • TOR Serine-Threonine Kinases / metabolism

Substances

  • Forkhead Transcription Factors
  • FoxK2 protein, mouse
  • Foxk1 protein, mouse
  • Insulin
  • mTOR protein, mouse
  • TOR Serine-Threonine Kinases
  • Glycogen Synthase Kinase 3