title: The role of protein kinases and protein phosphatases in the regulation of cardiac sarcoplasmic reticulum function.
abstract: Canine cardiac sarcoplasmic reticulum is phosphorylated by adenosine 3',5'-monophosphate (cAMP)-dependent and by calcium.calmodulin-dependent protein kinases on a 27,000 proteolipid, called phospholamban. Both types of phosphorylation are associated with an increase in the initial rates of Ca2+ transport by SR vesicles which reflects an increased turnover of elementary steps of the calcium ATPase reaction sequence. The stimulatory effects of the protein kinases on the calcium pump may be reversed by an endogenous protein phosphatase, which can dephosphorylate both the cAMP-dependent and the calcium.calmodulin-dependent sites on phospholamban. Thus, the calcium pump in cardiac sarcoplasmic reticulum appears to be under reversible regulation mediated by protein kinases and protein phosphatases.
authors.affiliation: Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Ohio.
authors.forename: E G
authors.initials: EG
authors.lastname: Kranias
authors.forename: R C
authors.initials: RC
authors.lastname: Gupta
authors.forename: G
authors.initials: G
authors.lastname: Jakab
authors.forename: H W
authors.initials: HW
authors.lastname: Kim
authors.forename: N A
authors.initials: NA
authors.lastname: Steenaart
authors.forename: S T
authors.initials: ST
authors.lastname: Rapundalo
mesh_terms: D000251:Adenosine Triphosphatases; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000032:analysis; D004285:Dogs; D006321:Heart / Q000502:physiology*; D010749:Phosphoprotein Phosphatases / Q000502:physiology*; D010766:Phosphorylation; D011494:Protein Kinases / Q000502:physiology*; D011506:Proteins / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000502:physiology*; D000099211:Phospholamban; D017871:Calcium-Calmodulin-Dependent Protein Kinases
chemical_list: D000251:Adenosine Triphosphatases; D002118:Calcium; D002135:Calcium-Binding Proteins; D010749:Phosphoprotein Phosphatases; D011494:Protein Kinases; D011506:Proteins; D000099211:Phospholamban; D017871:Calcium-Calmodulin-Dependent Protein Kinases