| Project/Area Number |
14580649
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Functional biochemistry
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| Research Institution | Kagawa University(Faculty of Medicine) |
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Principal Investigator |
TOKUMITSU Hiroshi Kagawa University, Medicine, Associate Professor, 医学部, 助教授 (20237077)
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| Co-Investigator(Kenkyū-buntansha) |
KOBAYASHI Ryoji Kagawa University, Medicine, Professor, 医学部, 教授 (00020917)
MURAO Koji Kagawa University, Medicine, Associate Professor, 医学部附属病院, 助手 (20291982)
ISHIDA Toshihiko Kagawa University, Medicine, Professor, 医学部, 教授 (50159737)
SAJI Ikutaro Sumitomo Pharmaceuticals Co. Ktd, Researcher, 研究本部, 主席研究員
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 2003: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2002: ¥3,100,000 (Direct Cost: ¥3,100,000)
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| Keywords | Calmodulin / Intracellular calcium / Protein kinase / CaM-kinase / CaM-KK / Protein kinase inhibitor / STO-609 / MLCK-A / 細胞内情報伝達 / リン酸化酵素カスケード / CREB |
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| Research Abstract |
Ca^<2+>/calmodulin-dependent protein kinases (CaM-Ks) constitute a diverse group of enzymes, which are involved in many cellular responses mediated by an increase in the concentration of intracellular calcium. Previous studies have demonstrated that two multifunctional CaM-kinases, CaM-KI and IV, are activated by phosphorylation of an activation loop Thr residue by an upstream CaM-kinase kinase (CaM-KK) resulting in a large increase in catalytic efficiency. In order to evaluate the physiological functions of CaM-KK and of the CaM-kinase cascade, we attempted to synthesize a potent and specific inhibitor of CaM-KK, STO-609. In this study, we characterize the effects of the inhibitor STO-609 on CaM-KK activity both in vitro and in intact cells. Furthermore, based on the results that the distinct sensitivity of CaM-KK isoforms to STO-609 is due to a single amino acid substitution (Val/Leu) in the ATP-binding pocket, we have generated an STO-609-resistant CaM-KK mutant, which might be useful for validating the pharmacological effects and specificity of STO-609 in vivo. We also have examined the activation mechanism of Dictyostelium MLCK-A by using constitutively active Ca^<2+>/calmodulin-dependent protein kinase kinase (CaM-KKc) as a surrogate MLCK-A kinase, indicating that the protein kinase cascade regulates MLCK-A in Dictyostelium analogous to CaM-kinase cascade.
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