title: A minimum size homologue of Ca2+/calmodulin-dependent protein kinase IV naturally occurring in zebrafish.
abstract: Ca(2+)/calmodulin-dependent protein kinase (CaMK) IV is a multifunctional Ser/Thr protein kinase that is predominantly expressed in the nuclei of neurons. CaMKIV consists of a catalytic domain and a regulatory (Ca(2+)/calmodulin binding and autoinhibitory) domain, which are located in the N-terminal and central regions, respectively. Here, we identified the zebrafish homologue of CaMKIV (zCaMKIV) on the basis of biochemical characterization. zCaMKIV showed similar biochemical properties as well as tissue and subcellular distributions to rat CaMKIV (rCaMKIV). However, zCaMKIV had a fairly small size with a molecular mass of about 40 kDa, and was devoid of a region corresponding to the C-terminal domain of rCaMKIV. Since zCaMKIV is composed of regions that are nearly equivalent to only a catalytic and a regulatory domain, it should represent a minimum size homologue possessing CaMKIV function. zCaMKIV and rCaMKIV differed in their substrate specificities, since rCaMKIV preferred histone H1 over myelin basic protein, while zCaMKIV did not. Moreover, zCaMKIV was more readily dephosphorylated by zebrafish nuclear CaMK phosphatase (CaMKP-N) than rCaMKIV. These results suggest that the C-terminal region of CaMKIV plays a role in interacting with its target and modulator proteins.
authors.affiliation: Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa 761-0795, Japan.
authors.forename: Takaki
authors.initials: T
authors.lastname: Nimura
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Sugiyama
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Sueyoshi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Shigeri
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Ishida
authors.forename: Isamu
authors.initials: I
authors.lastname: Kameshita
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4 / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D051379:Mice; D009474:Neurons; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D011994:Recombinant Proteins; D029961:Zebrafish Proteins; D054734:Calcium-Calmodulin-Dependent Protein Kinase Type 4; D010749:Phosphoprotein Phosphatases; C517871:ppm1e protein, zebrafish