Phosphorylation of the 165-kDa dihydropyridine/phenylalkylamine receptor from skeletal muscle by protein kinase C.

摘要: Dihydropyridine-sensitive Ca2+ channels exist in many different types of cells and are believed to be regulated by various protein phosphorylation dephosphorylation reactions. The present study concerns the a putative component dihydropyridine-sensitive calcium phospholipid-dependent kinase, kinase C. A skeletal muscle peptide 165 kDa, which is known contain receptors for dihydropyridines, phenylalkylamines, other channel effectors, was found an efficient substrate C when phosphorylated its membrane-bound state. Protein incorporated 1.5-2.0 mol phosphate/mol within 2 min into 165-kDa incubations carried out at 37 degrees In contrast peptide, purified detergent solution markedly less extent than counterpart; 0.1 incorporated. Preincubation membranes with several drugs activators or inhibitors had no specific effects on rate and/or compared that catalyzed cAMP-dependent not additive. Prior prevented subsequent Phosphoamino acid analysis indicated both serine threonine residues. Phosphopeptide mapping experiments showed one unique site and, addition, sites were either multifunctional Ca2+/calmodulin-dependent kinase. results suggest dihydropyridine/phenylalkylamine receptor could serve as physiological intact cells. It therefore possible regulation may occur level this peptide.