Protein Phosphatase Signaling in Cardiac Myocytes

Excerpt

A delicate balance of protein phosphorylation, performed by protein kinases, and dephosphorylation, performed by protein phosphatases, is required for the proper regulation of various cardiac functions such as Ca²⁺ signaling and excitation-contraction coupling. Abnormalities in this regulatory mechanism may contribute to the initiation and progression of a host of cardiovascular phenotypes, a major cause of mortality in the United States. Serine-threonine phosphatases, including protein phosphatase 1 (PP1), protein phosphatase 2A (PP2A), and protein phosphatase 2B (PP2B), perform the vast majority of dephosphorylation events in the heart. Their role in cardiovascular disease, specifically heart failure and atrial fibrillation, along with their distinctive structure, genetics, localization, and binding partners is reviewed. Specific emphasis is given to PP2A and mouse models that have explored its activity in the heart.