title: Phosphorylation and inactivation of HMG-CoA reductase at the AMP-activated protein kinase site in response to fructose treatment of isolated rat hepatocytes.
abstract: We have previously shown that incubation of isolated hepatocytes with fructose leads to elevation of AMP and activation of the AMP-activated protein kinase. We now show that this treatment causes marked inactivation of HMG-CoA reductase. Using immunoprecipitation from the microsomal fraction of 32P-labelled cells, we also show that this treatment leads to a 2.6-fold increase in the phosphorylation of the 100 kDa subunit of HMG-CoA reductase. Successive digestion of this 32P-labelled subunit with cyanogen bromide and endoproteinase Lys-C confirmed that Ser-871, the site phosphorylated in cell-free assays by the AMP-activated protein kinase, was the only site phosphorylated under these conditions.
authors.affiliation: Department of Biochemistry, The University, Dundee, Scotland, UK.
authors.forename: J G
authors.initials: JG
authors.lastname: Gillespie
authors.forename: D G
authors.initials: DG
authors.lastname: Hardie
mesh_terms: D000818:Animals; D001345:Autoradiography; D001665:Binding Sites; D015153:Blotting, Western; D002478:Cells, Cultured; D003488:Cyanogen Bromide; D010450:Endopeptidases; D004789:Enzyme Activation; D005632:Fructose / Q000494:pharmacology*; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism*; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D007525:Isoelectric Focusing; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D008297:Male; D008666:Metalloendopeptidases; D010766:Phosphorylation; D011233:Precipitin Tests; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D012694:Serine / Q000378:metabolism
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D005632:Fructose; D012694:Serine; D006903:Hydroxymethylglutaryl CoA Reductases; D011494:Protein Kinases; D010450:Endopeptidases; D008666:Metalloendopeptidases; C039830:peptidyl-Lys metalloendopeptidase; D003488:Cyanogen Bromide