<prompt> Function of Phospholamban is :Regulates Na K PumpTranspos calcium out of the mitrochondriaBinds actin with myosinCollects calcium into the sarcoplasmic  <response>: D i.e. Collects calcium into the sarcoplasmic reticulum Phospholamban is a protein contained within the sarcoplasmic reticulum that inhibits the activity of sarcoplasmic calcium pumpQ. Inactivation of phospholamban results in an increase in calcium sequestration by sarcoplasmic reticulum.Q - In cardiac muscle, the rapid sequestration of Ca2 shoens the duration of contraction. - In smooth muscle, sequestration causes the muscle to relax. - Phospholamban has little effect on skeletal muscle contraction. 