Sirt2 facilitates hepatic glucose uptake by deacetylating glucokinase regulatory protein

Nat Commun. 2018 Jan 2;9(1):30. doi: 10.1038/s41467-017-02537-6.

Abstract

Impaired hepatic glucose uptake (HGU) causes postprandial hyperglycemia in type 2 diabetes. Here, we show that diminished hepatic Sirt2 activity impairs HGU in obese diabetic mice. Hepatic Sirt2 overexpression increases HGU in high-fat diet (HFD)-fed obese diabetic mice and mitigates their impaired glucose tolerance. Hepatic Sirt2 knockdown in non-diabetic mice reduces HGU and causes impaired glucose tolerance. Sirt2 promotes glucose-dependent HGU by deacetylating K126 of glucokinase regulatory protein (GKRP). Glucokinase and GKRP glucose-dependent dissociation is necessary for HGU but is inhibited in hepatocytes derived from obese diabetic mice, depleted of Sirt2 or transfected with GKRP acetylation-mimicking mutants. GKRP deacetylation-mimicking mutants dissociate from glucokinase in a glucose concentration-dependent manner in obese diabetic mouse-derived hepatocytes and increase HGU and glucose tolerance in HFD-induced or db/db obese diabetic mice. We demonstrate that Sirt2-dependent GKRP deacetylation improves impaired HGU and suggest that it may be a therapeutic target for type 2 diabetes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Animals
  • Biological Transport
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Diabetes Mellitus, Type 2 / metabolism*
  • Gene Expression Regulation / physiology*
  • Gene Knockdown Techniques
  • Glucose / metabolism*
  • Intracellular Signaling Peptides and Proteins
  • Liver / enzymology*
  • Liver / metabolism
  • Mice
  • Mice, Obese
  • Mutation
  • Sirtuin 2 / genetics
  • Sirtuin 2 / metabolism*

Substances

  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • Gckr protein, mouse
  • Intracellular Signaling Peptides and Proteins
  • Sirt2 protein, mouse
  • Sirtuin 2
  • Glucose