STO-609, a specific inhibitor of the Ca2+/calmodulin-dependent protein kinase kinase
| Autor: | Tokumitsu, Hiroshi, Inuzuka, Hiroyuki, Ishikawa, Yumi, Ikeda, Masahiko, Saji, Ikutaro, Kobayashi, Ryoji |
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| Rok vydání: | 2003 |
| Předmět: |
animal structures
Calcium-Calmodulin-Dependent Protein Kinase Kinase Biology Mitogen-activated protein kinase kinase Protein Serine-Threonine Kinases Binding Competitive Biochemistry MAP2K7 Substrate Specificity Adenosine Triphosphate Genes Reporter Ca2+/calmodulin-dependent protein kinase Animals Humans Enzyme Inhibitors Phosphorylation Protein kinase A Protein Kinase Inhibitors Molecular Biology Gene Library Glutathione Transferase Kinase Autophosphorylation Cyclin-dependent kinase 2 Brain Cell Biology Isoquinolines Molecular biology Recombinant Proteins Rats Isoenzymes Kinetics Naphthalimides biology.protein Cyclin-dependent kinase 9 Benzimidazoles HeLa Cells |
| Zdroj: | Journal of Biological Chemistry. 278:4368 |
| ISSN: | 0021-9258 |
| DOI: | 10.1016/s0021-9258(19)30856-7 |
| Popis: | STO-609, a selective inhibitor of Ca(2+)/calmodulin-dependent protein kinase kinase (CaM-KK) was synthesized, and its inhibitory properties were investigated both in vitro and in vivo. STO-609 inhibits the activities of recombinant CaM-KK alpha and CaM-KK beta isoforms, with K(i) values of 80 and 15 ng/ml, respectively, and also inhibits their autophosphorylation activities. Comparison of the inhibitory potency of the compound against various protein kinases revealed that STO-609 is highly selective for CaM-KK without any significant effect on the downstream CaM kinases (CaM-KI and -IV), and the IC(50) value of the compound against CaM-KII is approximately 10 microg/ml. STO-609 inhibits constitutively active CaM-KK alpha (glutathione S-transferase (GST)-CaM-KK-(84-434)) as well as the wild-type enzyme. Kinetic analysis indicates that the compound is a competitive inhibitor of ATP. In transfected HeLa cells, STO-609 suppresses the Ca(2+)-induced activation of CaM-KIV in a dose-dependent manner. In agreement with this observation, the inhibitor significantly reduces the endogenous activity of CaM-KK in SH-SY5Y neuroblastoma cells at a concentration of 1 microg/ml (approximately 80% inhibitory rate). Taken together, these results indicate that STO-609 is a selective and cell-permeable inhibitor of CaM-KK and that it may be a useful tool for evaluating the physiological significance of the CaM-KK-mediated pathway in vivo as well as in vitro. |
| Databáze: | OpenAIRE |
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