PLN and heart failure: Since phosphorylation of most Ca2+-handling proteins has been shown to be altered in many models of experimental heart failure, which might lead to increased Ca2+ leakage, we next examined the effects of BO treatment on phospholamban (PLB) phosphorylation at Thr-17 and Ser-16, and RyR2 phosphorylation at Ser-2814 and Ser-2808.