Isoproterenol induces both cAMP- and calcium-dependent phosphorylation of phospholamban in canine heart in vivo.
The phosphorylation state of phospholamban in hearts of dogs depleted from catecholamines or treated with isoproterenol has been characterized using a sensitive back-phosphorylation method that allows to distinguish between cAMP-dependent and Ca2+/calmodulin-dependent phosphorylation occurring at the protein in situ. The data obtained demonstrate that in response to the beta-adrenergic agonist isoproterenol both the cAMP-dependent and the Ca2+/calmodulin-dependent phosphorylatable site are phosphorylated suggesting a physiological significance also for Ca2+-dependent phosphorylation of phospholamban in canine heart in vivo.
Karczewski
P
P
Central Institute for Cardiovascular Research, Acad. Sci. GDR, Berlin-Buch.
Bartel
S
S
Haase
H
H
Krause
E G
EG
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002147:Calmodulin / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D004285:Dogs; D007545:Isoproterenol / Q000494:pharmacology*; D007700:Kinetics; D009206:Myocardium / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D000099211:Phospholamban; D017871:Calcium-Calmodulin-Dependent Protein Kinases
D002118:Calcium; D002135:Calcium-Binding Proteins; D002147:Calmodulin; D000242:Cyclic AMP; D007545:Isoproterenol; D011494:Protein Kinases; D000099211:Phospholamban; D017871:Calcium-Calmodulin-Dependent Protein Kinases