Molecular cloning and characterization of CLICK-III/CaMKIgamma, a novel membrane-anchored neuronal Ca2+/calmodulin-dependent protein kinase (CaMK).
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.
Takemoto-Kimura
Sayaka
S
Department of Pharmacology, Kyoto University Faculty of Medicine, PRESTO-Japan Science and Technology Corporation, Sakyo-ku, Kyoto 606-8315, Japan.
Terai
Hisashi
H
Takamoto
Maki
M
Ohmae
Shogo
S
Kikumura
Shoko
S
Segi
Eri
E
Arakawa
Yoshiki
Y
Furuyashiki
Tomoyuki
T
Narumiya
Shuh
S
Bito
Haruhiko
H
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D019556:COS Cells; D002118:Calcium / Q000378:metabolism; D054729:Calcium-Calmodulin-Dependent Protein Kinase Type 1; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology* / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D003001:Cloning, Molecular; D006056:Golgi Apparatus / Q000201:enzymology; D006801:Humans; D007031:Hypothalamus / Q000378:metabolism; D017403:In Situ Hybridization; D008148:Lovastatin / Q000031:analogs & derivatives* / Q000494:pharmacology; D008156:Luciferases / Q000378:metabolism; D008565:Membrane Proteins; D051379:Mice; D008813:Mice, Inbred ICR; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000378:metabolism; D014018:Tissue Distribution; D014162:Transfection
D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C012258:mevastatin; D008148:Lovastatin; D008156:Luciferases; C517603:CAMK1G protein, human; D054729:Calcium-Calmodulin-Dependent Protein Kinase Type 1; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002118:Calcium