• Home
  • Search Results
  • Acetylation of glucokinase regulatory protein decreases glucose metabolism by suppressing glucokinase activity.

Acetylation of glucokinase regulatory protein decreases glucose metabolism by suppressing glucokinase activity.

Scientific reports (2015-12-02)
Joo-Man Park, Tae-Hyun Kim, Seong-Ho Jo, Mi-Young Kim, Yong-Ho Ahn
ABSTRACT

Glucokinase (GK), mainly expressed in the liver and pancreatic β-cells, is critical for maintaining glucose homeostasis. GK expression and kinase activity, respectively, are both modulated at the transcriptional and post-translational levels. Post-translationally, GK is regulated by binding the glucokinase regulatory protein (GKRP), resulting in GK retention in the nucleus and its inability to participate in cytosolic glycolysis. Although hepatic GKRP is known to be regulated by allosteric mechanisms, the precise details of modulation of GKRP activity, by post-translational modification, are not well known. Here, we demonstrate that GKRP is acetylated at Lys5 by the acetyltransferase p300. Acetylated GKRP is resistant to degradation by the ubiquitin-dependent proteasome pathway, suggesting that acetylation increases GKRP stability and binding to GK, further inhibiting GK nuclear export. Deacetylation of GKRP is effected by the NAD(+)-dependent, class III histone deacetylase SIRT2, which is inhibited by nicotinamide. Moreover, the livers of db/db obese, diabetic mice also show elevated GKRP acetylation, suggesting a broader, critical role in regulating blood glucose. Given that acetylated GKRP may affiliate with type-2 diabetes mellitus (T2DM), understanding the mechanism of GKRP acetylation in the liver could reveal novel targets within the GK-GKRP pathway, for treating T2DM and other metabolic pathologies.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Acetonitrile, anhydrous, 99.8%
Sigma-Aldrich
HEPES, ≥99.5% (titration)
Sigma-Aldrich
Sodium chloride, BioXtra, ≥99.5% (AT)
Sigma-Aldrich
HEPES, BioPerformance Certified, ≥99.5% (titration), suitable for cell culture
Sigma-Aldrich
Sodium chloride, for molecular biology, DNase, RNase, and protease, none detected, ≥99% (titration)
Sigma-Aldrich
IPTG, ≥99% (TLC), ≤0.1% Dioxane
Sigma-Aldrich
Sodium chloride solution, 0.9% in water, BioXtra, suitable for cell culture
Sigma-Aldrich
Phenylmethanesulfonyl fluoride, ≥98.5% (GC)
Sigma-Aldrich
Sodium chloride, BioReagent, suitable for cell culture, suitable for insect cell culture, suitable for plant cell culture, ≥99%
Sigma-Aldrich
Ethylenediaminetetraacetic acid, ACS reagent, 99.4-100.6%, powder
Sigma-Aldrich
Ethylenediaminetetraacetic acid, BioUltra, anhydrous, ≥99% (titration)
Sigma-Aldrich
Cycloheximide, from microbial, ≥94% (TLC)
Sigma-Aldrich
2-Deoxy-D-glucose, ≥98% (GC), crystalline
Sigma-Aldrich
Ammonium bicarbonate, ReagentPlus®, ≥99.0%
Sigma-Aldrich
Sodium chloride solution, 5 M in H2O, BioReagent, for molecular biology, suitable for cell culture
Sigma-Aldrich
HEPES buffer solution, 1 M in H2O
Sigma-Aldrich
Nicotinamide, BioReagent, suitable for cell culture, suitable for insect cell culture
Sigma-Aldrich
Cycloheximide, ≥95% (HPLC)
Sigma-Aldrich
Cycloheximide solution, Ready-Made Solution, microbial, 100 mg/mL in DMSO, 0.2 μm filtered
Sigma-Aldrich
Sodium chloride solution, 5 M
Sigma-Aldrich
Acetonitrile solution, contains 0.1 % (v/v) trifluoroacetic acid, suitable for HPLC
SAFC
Sodium chloride solution, 5 M
Sigma-Aldrich
Nicotinamide, ≥99.5% (HPLC)
Sigma-Aldrich
Acetonitrile, ACS reagent, ≥99.5%
SAFC
HEPES
Sigma-Aldrich
Ethylenediaminetetraacetic acid, anhydrous, crystalline, BioReagent, suitable for cell culture
Sigma-Aldrich
Ethylenediaminetetraacetic acid solution, 0.02% in DPBS (0.5 mM), sterile-filtered, BioReagent, suitable for cell culture
Sigma-Aldrich
Sodium chloride, meets analytical specification of Ph. Eur., BP, USP, 99.0-100.5%
Sigma-Aldrich
Ethylenediaminetetraacetic acid, purified grade, ≥98.5%, powder
Sigma-Aldrich
Trichostatin A, ≥98% (HPLC), from Streptomyces sp.