Progressive deterioration of myocardial function during acute and/or chronic heart disease probably involves defects in CA2+ uptake and release by the cardiac sacroplasmic reticulum (SR). It is vital, therefore, to develop an understanding of how the SR is regulated. Accordingly, this proposal will examine and elucidate the role of phosphorylation/dephosphorylation processes of SR in regulating its calcium pump both under in vitro and in vivo conditions. Work from several laboratories including ours has shown that SR function is modulated by cAMP-dependent phosphorylation. Recently, we have shown that cardiac SR is also phosphorylated by another intrinsic protein kinase which depends on calcium and calmodulin for its activity, and this phophorylation also appears to control Ca2+ transport. The proposed research will further elucidate the mechanism by which Ca2+-calmodulin-dependent phosphorylation regulates the Ca2+-ATPase activity and will determine the individual steps in the Ca2+-ATPase reaction sequence which are modulated by this phosphorylation. The interrelationship of cAMP-dependent and Ca2+-calmodulin-dependent phosphorylation as regulatory mechanisms for the Ca2+ pump will be studied. Special emphasis will be placed on the Ca2+-calmodulin-dependent protein kinase(s) and on the phosphoprotein phosphatase(s) in terms of purification and characterization since these are likely the enzymes involved in the """"""""reversible regulation"""""""" of SR function in vitro. Furthermore, this proposal will correlate the more biochemical in vitro findings with in vivo events, where SR phosphorylation will be studied using 32P-perfuse beating hearts. The dynamics of changes in SR phosphorylation/dephosphorylation and function during the response of the myocardium to Beta-adrenergic agonists/antagonists will be determined. Changes in SR will be correlated with changes in other cellular functions which occur in response to Beta-adrenergic agonists. The specificity of such existing correlations will be determined. The proposed research should provide important information concerning phosphorylation/dephosphorylation of SR as a regulatory mechanism for the calcium pump and, therefore, an important mechanisms of the contraction-relaxation cycle in cardiac muscle. These basic studies will lead to more rational experiments designed to elucidate the role of SR phosphorylation/dephosphorylation in models of ischemic heart disease and congestive heart failure.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL026057-06
Application #
3338423
Study Section
Cardiovascular and Pulmonary Research B Study Section (CVB)
Project Start
1981-07-01
Project End
1989-06-30
Budget Start
1986-07-01
Budget End
1987-06-30
Support Year
6
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Cincinnati
Department
Type
Schools of Medicine
DUNS #
City
Cincinnati
State
OH
Country
United States
Zip Code
45221
Liu, Guan-Sheng; Gardner, George; Adly, George et al. (2018) A novel human S10F-Hsp20 mutation induces lethal peripartum cardiomyopathy. J Cell Mol Med :
Bidwell, Philip A; Haghighi, Kobra; Kranias, Evangelia G (2018) The antiapoptotic protein HAX-1 mediates half of phospholamban's inhibitory activity on calcium cycling and contractility in the heart. J Biol Chem 293:359-367
Chen, Mu; Xu, Dongzhu; Wu, Adonis Z et al. (2018) Phospholamban regulates nuclear Ca2+ stores and inositol 1,4,5-trisphosphate mediated nuclear Ca2+ cycling in cardiomyocytes. J Mol Cell Cardiol 123:185-197
Liu, Guan-Sheng; Zhu, Hongyan; Cai, Wen-Feng et al. (2018) Regulation of BECN1-mediated autophagy by HSPB6: Insights from a human HSPB6S10F mutant. Autophagy 14:80-97
Bidwell, Philip A; Liu, Guan-Sheng; Nagarajan, Narayani et al. (2018) HAX-1 regulates SERCA2a oxidation and degradation. J Mol Cell Cardiol 114:220-233
Pollak, Adam J; Haghighi, Kobra; Kunduri, Swati et al. (2017) Phosphorylation of serine96 of histidine-rich calcium-binding protein by the Fam20C kinase functions to prevent cardiac arrhythmia. Proc Natl Acad Sci U S A 114:9098-9103
Kranias, Evangelia G; Hajjar, Roger J (2017) The Phospholamban Journey 4 Decades After Setting Out for Ithaka. Circ Res 120:781-783
Watanabe, Shin; Ishikawa, Kiyotake; Fish, Kenneth et al. (2017) Protein Phosphatase Inhibitor-1 Gene Therapy in a Swine Model of Nonischemic Heart Failure. J Am Coll Cardiol 70:1744-1756
Mazzocchi, G; Sommese, L; Palomeque, J et al. (2016) Phospholamban ablation rescues the enhanced propensity to arrhythmias of mice with CaMKII-constitutive phosphorylation of RyR2 at site S2814. J Physiol 594:3005-30
Stillitano, Francesca; Turnbull, Irene C; Karakikes, Ioannis et al. (2016) Genomic correction of familial cardiomyopathy in human engineered cardiac tissues. Eur Heart J 37:3282-3284

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