title: Activation of rat liver cytosolic 3-hydroxy-3-methylglutaryl coenzyme A reductase kinase by adenosine 5'-monophosphate.
abstract: Inactivation of 3-hydroxy-3-methylglutaryl Coenzyme A reductase by reductase kinase and ATP-Mg needs either ADP or 5'-AMP as cofactors. 5'-AMP is a more potent activator of cytosolic reductase kinase than ADP. This capacity is expressed by increasing not only the rate of reductase inactivation, but also the rate of reductase phosphorylation from [gamma-32P]ATP. Activation constants, Ka, for 5'-AMP and ADP are 20 microM and 420 microM respectively. Neither 3'-AMP nor 2'-AMP activate reductase kinase. Other nucleoside monophosphates like UMP, CMP and GMP cannot replace 5'-AMP as activators of reductase kinase.
mesh_terms: D055372:AMP-Activated Protein Kinases; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000249:Adenosine Monophosphate / Q000494:pharmacology*; D000494:Allosteric Regulation; D000818:Animals; D003600:Cytosol / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D009097:Multienzyme Complexes / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D051381:Rats
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D009097:Multienzyme Complexes; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D008274:Magnesium