title: Ca2+/calmodulin-dependent protein kinase II phosphorylation regulates the cardiac ryanodine receptor.
abstract: The cardiac ryanodine receptor (RyR2)/calcium release channel on the sarcoplasmic reticulum is required for muscle excitation-contraction coupling. Using site-directed mutagenesis, we identified the specific Ca2+/calmodulin-dependent protein kinase II (CaMKII) phosphorylation site on recombinant RyR2, distinct from the site for protein kinase A (PKA) that mediates the "fight-or-flight" stress response. CaMKII phosphorylation increased RyR2 Ca2+ sensitivity and open probability. CaMKII was activated at increased heart rates, which may contribute to enhanced Ca2+-induced Ca2+ release. Moreover, rate-dependent CaMKII phosphorylation of RyR2 was defective in heart failure. CaMKII-mediated phosphorylation of RyR2 may contribute to the enhanced contractility observed at higher heart rates. The full text of this article is available online at http://circres.ahajournals.org.
authors.affiliation: Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, 630 W 168th St, P&S 9-401, Box 65, New York, NY 10032, USA.
authors.forename: Xander H T
authors.initials: XH
authors.lastname: Wehrens
authors.forename: Stephan E
authors.initials: SE
authors.lastname: Lehnart
authors.forename: Steven R
authors.initials: SR
authors.lastname: Reiken
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Marks
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000502:physiology*; D002304:Cardiac Pacing, Artificial; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000209:etiology / Q000378:metabolism; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009203:Myocardial Infarction / Q000150:complications; D009206:Myocardium / Q000201:enzymology*; D010766:Phosphorylation; D010768:Phosphoserine / Q000737:chemistry; D011499:Protein Processing, Post-Translational; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000502:physiology; D019837:Ryanodine Receptor Calcium Release Channel / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013449:Sulfonamides / Q000494:pharmacology; D022021:Tacrolimus Binding Proteins / Q000378:metabolism; D014463:Ultrasonography; D000096926:Benzenesulfonamides
chemical_list: D000318:Adrenergic beta-Agonists; D001596:Benzylamines; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D004791:Enzyme Inhibitors; D007545:Isoproterenol; D010768:Phosphoserine; D011993:Recombinant Fusion Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D013449:Sulfonamides; D022021:Tacrolimus Binding Proteins; C072105:KN 93; D000096926:Benzenesulfonamides; C403484:tacrolimus binding protein 1B