Casein kinase II-catalysed phosphorylation of calmodulin is altered by amino acid deletions in the central helix of calmodulin.
Calmodulin is phosphorylated by casein kinase II on Thr-79, Ser-81, Ser-101 and Thr-117. To determine the consensus sequences for casein kinase II in intact calmodulin, we examined casein kinase II-mediated phosphorylation of engineered calmodulins with 1-4 deletions in the central helical region (positions 81-84). Total casein kinase II-catalyzed phosphate incorporation into all deleted calmodulins was similar to control calmodulin. Neither CaM delta 84 (Glu-84 deleted) nor CaM delta 81-84 (Ser-81 to Glu-84 deleted) has phosphate incorporated into Thr-79 or Ser-81, but both exhibit increased phosphorylation of residues Ser-101 and Thr-117. These data suggest that phosphoserine in the +2 position may be a specificity determinant for casein kinase II in intact proteins and/or secondary structures are important in substrate recognition by casein kinase II.
Sacks
D B
DB
Department of Pathology, Brigham and Women's Hospital, Boston, MA.
Davis
H W
HW
Crimmins
D L
DL
Persechini
A
A
McDonald
J M
JM
D000595:Amino Acid Sequence; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D002147:Calmodulin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D047390:Casein Kinase II; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017384:Sequence Deletion; D012694:Serine; D013379:Substrate Specificity; D013912:Threonine
D002147:Calmodulin; D013912:Threonine; D012694:Serine; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D002118:Calcium