Identification and characterization of CaMKP-N, nuclear calmodulin-dependent protein kinase phosphatase.
Calmodulin-dependent protein kinase phosphatase (CaMKP) dephosphorylates and concomitantly deactivates multifunctional Ca(2+)/calmodulin-dependent protein kinases (CaMKs), such as CaMKI, CaMKII, and CaMKIV. In the present study, a nuclear CaMKP-related protein, CaMKP-N, was identified. This protein consisted of 757 amino acid residues with a calculated molecular weight of 84,176. Recombinant CaMKP-N dephosphorylated CaMKIV. The activity of CaMKP-N requires Mn(2+) ions and is stimulated by polycations. Transiently expressed CaMKP-N in COS-7 cells was localized in the nucleus. This finding together with previous reports regarding localization of CaMKs indicates that CaMKP-N dephosphorylates CaMKIV and nuclear CaMKII, whereas CaMKP dephosphorylates CaMKI and cytosolic CaMKII.
Takeuchi
M
M
Department of Biochemistry, Asahikawa Medical College, Asahikawa, Hokkaido 078-8510, Japan.
Ishida
A
A
Kameshita
I
I
Kitani
T
T
Okuno
S
S
Fujisawa
H
H
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology*; D002522:Chlorocebus aethiops; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D007313:Insecta; D008345:Manganese / Q000378:metabolism; D008969:Molecular Sequence Data; D004676:Myelin Basic Protein / Q000494:pharmacology; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation; D011073:Polyamines / Q000494:pharmacology; D000071228:Polyelectrolytes; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment; D013347:Subcellular Fractions; D014018:Tissue Distribution
D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D008345:Manganese; D004676:Myelin Basic Protein; D010749:Phosphoprotein Phosphatases; D011073:Polyamines; D000071228:Polyelectrolytes; D011994:Recombinant Proteins; C517683:CAMK4 protein, human