1993 Fiscal Year Final Research Report Summary
Regulatory role of ca^<2+> -binging protein requcalcin in signal transduction system and its mechanism
| Project/Area Number |
04671362
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Biological pharmacy
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| Research Institution | University of Shizuoka |
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Principal Investigator |
YAMAGUCHI Masayoshi University of Shizuoka, Graduate School, Professor, 大学院・独立研究科, 教授 (70046308)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Regucalcin / Ca^<2+>-binding protein / Signal transduction system / liver plasma menbrane (Ca^<2+>-Mg^<2+>)-ATPase / Nuclear Ca^<2+> transport system / Nuclear Ca2+-ATPase |
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| Research Abstract |
The requlatory role of Ca^<2+> -binding protein requcalcin in signal trasnduction system of liver cells was investigated, and the following results were obtained.
1) Requcalcin activates directly (Ca^<2+>-Mg^<2+>)-ATPase in liver plasma membranes, an the activation is not involved in the Ca^<2+>-dependent phosphorylation of the enzyme.
2) The activating mechanism of requcalcin on (Ca^<2+>-Mg^<2+>)-ATPase is not involved on GTP-binding protein which modulates the receptor-mediated hormonal effect in rat liver plasma menbranes.
3) Regucalcin stimulates Ca^<2+> release from liver nuclei, and the effect is not influenced by calmodulin antagonist, suggesting that regucalcin can regulate the Ca^2 transport system in rat liver nuclei.
4) Arachidonic acid inhibited Ca^<2+> uptake and stimulated Ca^<2+> release in rat liver nuclei.
5) NAD^+ has an inhibitory effect on nuclear Ca^<2+> uptake.
6) Liver nuclei were Ca^<2+> -ATPase which can taken up Ca^<2+>.Rgucalcin had no effect on the enzyme activity, although arachidonic acid and NAD^+ inhibited the enzyme activity.
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