Phosphorylation and dephosphorylation of hormone-sensitive lipase. Interactions between the regulatory and basal phosphorylation sites.
Phosphorylation of the basal site with glycogen synthase kinase-4 enhanced the rate of phosphorylation of the regulatory site by cyclic AMP-dependent protein kinase 1.7-fold. In contrast, the phosphorylation state of the regulatory site did not affect the rate of phosphorylation of the basal site with glycogen synthase kinase-4. The rate of dephosphorylation of either the regulatory or the basal phosphorylation site by protein phosphatase-1, 2A or 2C was independent of the phosphorylation state of the other site. These results suggest that the basal phosphorylation site could play an indirect role in the control of the hormone-sensitive lipase activity in the adipocyte by functioning as a recognition site for the cyclic AMP-dependent protein kinase in the phosphorylation of the activity-controlling regulatory phosphorylation site in response to lipolytic hormones.
Olsson
H
H
Department of Medical and Physiological Chemistry 4, University of Lund, Sweden.
Belfrage
P
P
D000818:Animals; D001665:Binding Sites; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D000242:Cyclic AMP / Q000494:pharmacology*; D038341:Glycogen Synthase Kinases; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D054645:Protein Phosphatase 1; D011817:Rabbits; D051381:Rats; D002787:Sterol Esterase / Q000378:metabolism*
D000242:Cyclic AMP; D011494:Protein Kinases; D038341:Glycogen Synthase Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002787:Sterol Esterase; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1