DISTINCT TYPE-2A PROTEIN PHOSPHATASES ACTIVATE HMGCOA REDUCTASE AND ACETYL-COA CARBOXYLASE IN LIVER

Acetyl-CoA carboxylase and HMGCoA reductase are inactivated by the sam e AMP-activated protein kinase and are activated by type-2A protein ph osphatase. To determine whether the same species of protein phosphatas e-2A were involved, we studied the interconversion of acetyl-CoA carbo xylase and HMGCoA reductase in isolated rat hepatocytes. We show that (i) these enzymes are differently regulated in hepatocytes and (ii) th e species of type-2A protein phosphatase involved in their activation are different and can be separated by anion-exchange chromatography. ( C) 1997 Federation of European Biochemical Societies.