Molecular cloning and characterization of CLICK-III/CaMKIgamma, a novel membrane-anchored neuronal Ca2+/calmodulin-dependent protein kinase (CaMK)

• Published in: The Journal of biological chemistry 2003-05, Vol.278 (20), p.18597
• Main Authors: Takemoto-Kimura, Sayaka, Terai, Hisashi, Takamoto, Maki, Ohmae, Shogo, Kikumura, Shoko, Segi, Eri, Arakawa, Yoshiki, Furuyashiki, Tomoyuki, Narumiya, Shuh, Bito, Haruhiko
• Format: Article
• Language: English
• Subjects: Amino Acid Motifs; Amino Acid Sequence; Animals; Blotting, Northern; Blotting, Western; Calcium - metabolism; Calcium-Calmodulin-Dependent Protein Kinase Type 1; Calcium-Calmodulin-Dependent Protein Kinases - chemistry; Calcium-Calmodulin-Dependent Protein Kinases - genetics; Calcium-Calmodulin-Dependent Protein Kinases - metabolism; Cell Membrane - enzymology; Cell Membrane - metabolism; Cell Nucleus - metabolism; Cells, Cultured; Cloning, Molecular; COS Cells; Golgi Apparatus - enzymology; Humans; Hypothalamus - metabolism; In Situ Hybridization; Lovastatin - analogs & derivatives; Lovastatin - pharmacology; Luciferases - metabolism; Membrane Proteins; Mice; Mice, Inbred ICR; Microscopy, Fluorescence; Molecular Sequence Data; Nerve Tissue Proteins - chemistry; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; Neurons - metabolism; Plasmids - metabolism; Precipitin Tests; Protein Structure, Tertiary; Sequence Homology, Amino Acid; Subcellular Fractions - metabolism; Tissue Distribution; Transfection
• ISSN: 0021-9258

During a screen for novel putative Ca(2+)/calmodulin-dependent protein kinase (CaMK)-like CREB kinases (CLICKs), we have cloned a full-length cDNA for CLICK-III/CaMKIgamma, an isoform of the CaMKI family with an extended C-terminal domain ending with CAAX motif (where AA is aliphatic acid). As expected from the similarity of its kinase domain with the other CaMKI isoforms, full activation of CLICK-III/CaMKIgamma required both Ca(2+)/CaM and phosphorylation by CaMKK. We also found that Ca(2+)/cAMP-response element-binding protein (CREB) was a good substrate for CLICK-III/CaMKIgamma, at least in vitro. Interestingly enough, CLICK-III/CaMKIgamma transcripts were most abundant in neurons, with the highest levels in limited nuclei such as the central nucleus of the amygdala (CeA) and the ventromedial hypothalamus. Consistent with the presence of the CAAX motif, CLICK-III/CaMKIgamma was found to be anchored to various membrane compartments, especially to Golgi and plasma membranes. Both point mutation in the CAAX motif and treatment with compactin, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, disrupted such membrane localization, suggesting that membrane localization of CLICK-III/CaMKIgamma occurred in a prenylation-dependent way. These findings provide a novel mechanism by which neuronal CaMK activity could be targeted to specific membrane compartments.