title: Direct evidence for protein phosphatase-catalyzed dephosphorylation/deactivation of hormone-sensitive lipase from adipose tissue.
abstract: Incubation of purified hormone-sensitive lipase, 32P-phosphorylated with the catalytic subunit of cyclic AMP-dependent protein kinase and [gamma-32P]ATP-Mg2+, with partially purified protein phosphatase from the same tissue caused a rapid decrease of the 32P content of the enzyme protein. Deactivation of the lipase towards emulsified trioleoylglycerol was temporally related to the dephosphorylation with approx. 80% decrease of both phosphorylation and activity within 30 min. Addition of ATP-Mg and cyclic AMP-dependent protein kinase to the dephosphorylated lipase was shown to rephosphorylate and reactivate the enzyme. These findings are the first direct demonstration of reversible protein phosphatase-catalyzed dephosphorylation/deactivation of hormone-sensitive lipase.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000273:Adipose Tissue / Q000201:enzymology*; D000818:Animals; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism; D051381:Rats; D002787:Sterol Esterase / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000255:Adenosine Triphosphate; D011494:Protein Kinases; D002787:Sterol Esterase; D010749:Phosphoprotein Phosphatases