Excitation Contraction CouplingMuscle ContractionIsometric ContractionMyocytes, CardiacPhosphorylationMyocardial ContractionSerineCalciumTyrosineHeartUterine ContractionEnzyme ActivationProtein-Serine-Threonine KinasesCells, CulturedProtein KinasesMolecular Sequence DataAmino Acid SequencePhosphoproteinsTime FactorsCell LineOxidative PhosphorylationCardiac OutputMuscle, SmoothElectric StimulationKineticsPhosphoserineProtein Kinase CEnzyme InhibitorsThreonineProtein-Tyrosine KinasesMyocardiumRats, Sprague-DawleyMuscle, SkeletalProtein BindingArrhythmias, CardiacSignal TransductionCyclic AMP-Dependent Protein Kinases