title: Phosphorylation by casein kinase II affects the interaction of caldesmon with smooth muscle myosin and tropomyosin.
abstract: Smooth muscle caldesmon was phosphorylated by casein kinase II, and the effects of phosphorylation on the interaction of caldesmon and its chymotryptic peptides with myosin and tropomyosin were investigated. The N-terminal chymotryptic peptide of caldesmon of molecular mass 27 kDa interacted with myosin. Phosphorylation of Ser-73 catalysed by casein kinase II resulted in a 2-fold decrease in the affinity of the native caldesmon (or its 27 kDa N-terminal peptide) for smooth muscle myosin. At low ionic strength, caldesmon and its N-terminal peptides of molecular masses 25 and 27 kDa were retarded on a column of immobilized tropomyosin. Phosphorylation of Ser-73 led to a 2-4-fold decrease in the affinity of caldesmon (or its N-terminal peptides) for tropomyosin. Thus phosphorylation of Ser-73 catalysed by casein kinase II affects the interaction of caldesmon with both smooth muscle myosin and tropomyosin.
authors.affiliation: Department of Biochemistry, School of Biology, Moscow State University, Russia.
authors.forename: N V
authors.initials: NV
authors.lastname: Bogatcheva
authors.forename: A V
authors.initials: AV
authors.lastname: Vorotnikov
authors.forename: K G
authors.initials: KG
authors.lastname: Birukov
authors.forename: V P
authors.initials: VP
authors.lastname: Shirinsky
authors.forename: N B
authors.initials: NB
authors.lastname: Gusev
mesh_terms: D000818:Animals; D002148:Calmodulin-Binding Proteins / Q000378:metabolism*; D047390:Casein Kinase II; D004372:Ducks; D008099:Liver / Q000201:enzymology; D009130:Muscle, Smooth / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011817:Rabbits; D014335:Tropomyosin / Q000378:metabolism*
chemical_list: D002148:Calmodulin-Binding Proteins; D014335:Tropomyosin; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D009218:Myosins