The ATP,Mg-dependent protein phosphatase: regulation by casein kinase-1.
The free modulator subunit of the ATP,Mg-dependent phosphatase is phosphorylated up to 1 mol per mol by casein kinase-1, up to 1.85 mol per mol after dephosphorylation by the PCSH1 phosphatase, but 10-fold less when purified in the presence of NaF, suggesting an in vivo phosphorylation of the casein kinase-1 sites. Peptide mapping of 32P-modulator labeled by casein kinase-1 or -2 shows a different phosphorylation pattern. Phosphorylation of the inactive phosphatase by casein kinase-1 prevents the subsequent kinase FA-mediated activation, while it does not impair the activated phosphatase.
Agostinis
P
P
Afdeling Biochemie, Faculteit Geneeskunde, Katholieke Universiteit te Leuven, Belgium.
Vandenheede
J R
JR
Goris
J
J
Meggio
F
F
Pinna
L A
LA
Merlevede
W
W
D047388:Casein Kinases; D004789:Enzyme Activation; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000502:physiology*
D010750:Phosphoproteins; D011494:Protein Kinases; D047388:Casein Kinases; D010749:Phosphoprotein Phosphatases