Dissection of the dual function of the beta-subunit of protein kinase CK2 ('casein kinase-2'): a synthetic peptide reproducing the carboxyl-terminal domain mimicks the positive but not the negative effects of the whole protein.
The dual function of the regulatory beta-subunit of protein kinase CK2 is highlighted by its ability to abolish calmodulin phosphorylation in contrast to its stimulatory effect on the phosphorylation of peptide substrates. Here we show that a synthetic peptide reproducing the C-terminal region of the beta-subunit (beta[170-215]) stimulates to a similar extent the phosphorylation of either the peptide substrate or calmodulin and also protects the catalytic alpha-subunit against thermal inactivation as efficiently as full-length beta-subunit. These data show that the positive and negative functions of the beta-subunit reside in physically separated domains and that the elements responsible for positive regulation are located in the C-terminal region.
Marin
O
O
Dipartimento di Chimica Biologica, CRIBI and CNR, Università di Padova, Italy.
Meggio
F
F
Boldyreff
B
B
Issinger
O G
OG
Pinna
L A
LA
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002147:Calmodulin / Q000378:metabolism; D047390:Casein Kinase II; D004795:Enzyme Stability; D006358:Hot Temperature; D008099:Liver / Q000201:enzymology; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D012045:Regulatory Sequences, Nucleic Acid; D013329:Structure-Activity Relationship
D002147:Calmodulin; D046911:Macromolecular Substances; D010446:Peptide Fragments; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases