| Project/Area Number |
10558104
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Functional biochemistry
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
SAKAGUCHI Masao KYUSHU UNIVERSITY, Faculty of Medical Sciences, Associate Professor, 大学院・医学研究院, 助教授 (30205736)
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| Co-Investigator(Kenkyū-buntansha) |
KUSANO Kazutomi Eisai Co., Ltd., Drug Safety and Disposition Research Laboratories, Researcher, 薬物評価研究所, 研究員
TOKUDA Hajime University of Tokyo, Institute of Molecular and Cellular Biosciences, Professor, 分子細胞生物学研究所, 教授 (40125943)
OMURA Tsuneo Kyushu University, Professor Emeritus, 名誉教授 (80029933)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥8,100,000 (Direct Cost: ¥8,100,000)
Fiscal Year 2000: ¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1999: ¥4,500,000 (Direct Cost: ¥4,500,000)
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| Keywords | signal sequence / endoplasmic reticulum / topolgy / cytochrome P450 / 薬物代謝 / 大腸菌 / タンパク質立体構造 / 膜タンパク質 / 膜蛋白質 |
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| Research Abstract |
(1) We have investigated how the amino- (N) -terminal structure affected the expression level of cytochrome P450s in the E coli cells. The N-terminal sequence contains three characteristic segments ; hydrophobic sequence that functions as a type I signal-anchor sequence (SA-I), basic residues-rich sequence (BS), and proline rich region (PR). SA-I and BS could be exchanged among molecular species of P450, whereas PR could not. Specific isoform requires its specific PR sequence. The PR can be removed from folded molecule, indicating that this segment is critical only during the folding process. (2) The requirement of PR for correct folding was also demonstrated using other P450 molecules, mitochondrial and bacterial soluble P450s. Thus we concluded that PR is critical for correct folding of all cytochrome P450 isoforms. (3) We clarified topogenic process of the SA-I membrane proteins on the ER membrane. (4) We clarified targeting motif for the correct location of the SA-I protein of mitochondrial outer membrane. (5) NADPH-cytochrome P450 reductase possesses also the SA-I sequence. (6) We also presented the several lines of evidence demonstrating that SA-I plays a critical role for integration of various membrane proteins including the multispanning membrane proteins.
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