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.
Department of Biological Chemistry, School of Medicine, University of Maryland, Baltimore 21201.
A
A
Wawrzynow
J H
JH
Collins
N V
NV
Bogatcheva
A V
AV
Vorotnikov
N B
NB
Gusev
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