Protein kinase A phosphorylation of the cardiac calcium release channel (ryanodine receptor) in normal and failing hearts. Role of phosphatases and response to isoproterenol.
The cardiac ryanodine receptor/calcium release channel (RyR2) on the sarcoplasmic reticulum (SR) comprises a macromolecular complex that includes a kinase and two phosphatases that are bound to the channel via targeting proteins. We previously found that the RyR2 is protein kinase A (PKA)-hyperphosphorylated in end-stage human heart failure. Because heart failure is a progressive disease that often evolves from hypertrophy, we analyzed the RyR2 macromolecular complex in several animal models of cardiomyopathy that lead to heart failure, including hypertrophy, and at different stages of disease progression. We now show that RyR2 is PKA-hyperphosphorylated in diverse models of heart failure and that the degree of RyR2 PKA phosphorylation correlates with the degree of cardiac dysfunction. Interestingly, we show that RyR2 PKA hyperphosphorylation can be lost during perfusion of isolated hearts due to the activity of the endogenous phosphatases in the RyR2 macromolecular complex. Moreover, infusion of isoproterenol resulted in PKA phosphorylation of RyR2 in rat, indicating that systemic catecholamines can activate phosphorylation of RyR2 in vivo. These studies extend our previous analyses of the RyR2 macromolecular complex, show that both the kinase and phosphatase activities in the macromolecular complex are regulated physiologically in vivo, and suggest that RyR2 PKA hyperphosphorylation is likely a general feature of heart failure.
Reiken
Steven
S
Center for Molecular Cardiology, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
Gaburjakova
Marta
M
Guatimosim
Silvia
S
Gomez
Ana M
AM
D'Armiento
Jeanine
J
Burkhoff
Daniel
D
Wang
Jie
J
Vassort
Guy
G
Lederer
W Jonathan
WJ
Marks
Andrew R
AR
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004195:Disease Models, Animal; D006321:Heart / Q000502:physiology / Q000503:physiopathology; D006333:Heart Failure / Q000378:metabolism* / Q000503:physiopathology; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D046911:Macromolecular Substances; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D009203:Myocardial Infarction / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism; D018408:Patch-Clamp Techniques; D010766:Phosphorylation; D051381:Rats; D020303:Rats, Inbred Dahl; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000235:genetics / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism*; D013566:Sympathomimetics / Q000494:pharmacology; D000099211:Phospholamban
D002118:Calcium; D002135:Calcium-Binding Proteins; D017868:Cyclic AMP-Dependent Protein Kinases; D007545:Isoproterenol; D046911:Macromolecular Substances; D020781:Matrix Metalloproteinase 1; D011943:Receptors, Adrenergic, beta; D019837:Ryanodine Receptor Calcium Release Channel; D013566:Sympathomimetics; D000099211:Phospholamban