Cyclic AMP-dependent phosphorylation of phospholamban regulates the Ca2+ pump ATPase in the sarcoplasmic reticulum, modulating Ca2+ transients and the myocardial contractile response.
Ca2+ transients in myocardial cells are modulated by cyclic AMP-dependent phosphorylation of a protein in the sarcoplasmic reticulum. This protein, termed phospholamban, serves to regulate the Ca2+ pump ATPase of this membrane, thus altering the mode of Ca2+ transients and the myocardial contractile response. Elucidating the structure of phospholamban and its intimate interaction with the Ca2+ pump ATPase should provide the basis for understanding, at the molecular level, how the cAMP system contributes to excitation-contraction coupling in muscle cells.
Tada et al. (Mon,) reported a review. Cyclic AMP-dependent phosphorylation of phospholamban regulates the Ca2+ pump ATPase in the sarcoplasmic reticulum, modulating Ca2+ transients and the myocardial contractile response.