Regulates myosin phosphatase activity. Augments Ca(2+) sensitivity of the contractile apparatus.
Subcellular locations: Cytoplasm, Cytoskeleton, Cytoplasm, Cytoskeleton, Stress fiber
Along actomyosin filaments.
Detected in skeletal muscle, fetal and adult heart, brain, placenta, kidney, spleen, thymus, pancreas and lung. Isoform 3 and isoform 4 are heart specific.