The roles of calpastatin and calmodulin in the regulation of calcium channel
| Project/Area Number |
15570137
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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 |
Biophysics
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| Research Institution | Kagoshima University |
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Principal Investigator |
HAO Li-ying Kagoshima University, Graduate School of Medical and Dental Sciences, Research Associate, 大学院・医歯学総合研究科, 助手 (40311881)
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| Co-Investigator(Kenkyū-buntansha) |
KUROKI Sachiko Fukushima Medical University, Faculty of Medicine, Research Associate, 医学部, 助手 (80343391)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2004: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2003: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | calmodulin / calpastatin / CaMKII / Ca^<2+> channel / run-down / CaMK / Ca^<2+> channel |
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| Research Abstract |
Voltage-gated L-type Ca^<2+> channels control diverse physiological functions including gene transcription, rhythmic firing, synaptic transmission, hormone secretion and excitation-contraction coupling. Activity of L-type Ca^<2+> channel decreases when the cytoplasmic side of the channel is perfused with an artificial physiological solution (run-down phenomenon). The mechanism of run-down is still unknown. We have previously reported that both calpastatin(CS) and calmodulin(CaM) can recover Ca^<2+> channel activity after run-down. In this study, we have investigated the relations and the mechanisms of calmodulin and calpastatin in the activation of Ca^<2+> channel and the reversion of run-down. The main results are as follows. (1)The run-down reversing effect of CaM depends on channel phosphorylation state. CaM kinase II keeps the channel in a state that can be reactivated by CaM. (2)Domain L of CS reactivates the L-type Ca^<2+> channel. By screening the short peptides of domain L, we found that the effective region of CS is located in the amino acid residues 45-64 of domain L. (3)To investigate the relations of CS and CaM, binding between these two molecules were examined with GST-fusion protein pull-down assay. The result shows that CS and CaM bind each other in the presence of Ca^<2+>. (4)Binding sites of CS to Ca^<2+> channel were also investigated. CS might bind to the region that has already confirmed as CaM binding region.
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Report
(3 results)
Research Products
(16 results)
