Identification of the site phosphorylated by casein kinase II in smooth muscle caldesmon.
Phosphorylation of avian gizzard caldesmon by casein kinase II was investigated. The enzyme incorporates about 1 mol of phosphate per mol of caldesmon. All sites of phosphorylation are located in short chymotryptic peptides with Mr 25-27 kDa or in the short N-terminal peptide formed after cleavage of chicken gizzard caldesmon at Cys153. The primary structure of the tryptic peptide containing the main site of duck gizzard caldesmon phosphorylation is S-E-V-N-A-Q-N-X-V-A-E-D-E-T-K, where X is an unidentified residue, presumed to be phosphoserine. Thus, Ser73 is the main site phosphorylated by casein kinase II in avian gizzard caldesmon.
Wawrzynow
A
A
Department of Biological Chemistry, School of Medicine, University of Maryland, Baltimore 21201.
Collins
J H
JH
Bogatcheva
N V
NV
Vorotnikov
A V
AV
Gusev
N B
NB
D000595:Amino Acid Sequence; D000818:Animals; D002148:Calmodulin-Binding Proteins / Q000378:metabolism*; D047388:Casein Kinases; D002851:Chromatography, High Pressure Liquid; D004372:Ducks; D005895:Gizzard, Avian / Q000201:enzymology; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000201:enzymology*; D010446:Peptide Fragments / Q000302:isolation & purification; D010748:Phosphopeptides / Q000302:isolation & purification; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D013379:Substrate Specificity
D002148:Calmodulin-Binding Proteins; D010446:Peptide Fragments; D010748:Phosphopeptides; D011494:Protein Kinases; D047388:Casein Kinases