Which is the main regulatory molecule of SERCA2A function in the cardiac muscle?
SERCA2a activity is regulated by phosphorylation of another SR protein, Phospholamban (PLN). Phospholamban (PLB) inhibits the activity of SERCA2a, the Ca(2+)-ATPase in cardiac sarcoplasmic reticulum, by decreasing the apparent affinity of the enzyme for Ca(2+).