Phospholamban

Phospholamban (PLB, PLN ) is a protein in heart muscle cells, which controls the uptake of Ca2 in the sarcoplasmic reticulum: In the dephosphorylated state inhibits the SERCA ( Sarcoplasmic / endoplasmic reticulum calcium ATPase), which is integrated into the membrane of the sarcoplasmic reticulum Ca2 - pump. After β -adrenergic stimulation of cardiac muscle cell phospholamban is phosphorylated by protein kinase A, its inhibitory effect is abolished so that more Ca2 is taken up into the sarcoplasmic reticulum and can relax the heart muscle cell faster. The protein has therefore phosphorylated state in a positive lusitropic effect.

Mutations at the PLB gene can cause a rare dilated cardiomyopathy type 1P.

Human Genome Organisation Proteinkinase A
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