SERCA activity is tightly regulated by several mechanisms. [Phospholamban](), a regulatory protein, inhibits SERCA pumps when it is dephosphorylated. Upon phosphorylation, phospholamban's inhibitory effect is relieved, thus enhancing SERCA activity. Other regulatory proteins include sarcolipin and myoregulin, which also modulate SERCA function. Additionally, calcium levels themselves provide feedback regulation to ensure proper pump activity.
