| Project/Area Number |
08457034
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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 | 一般 |
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| Research Field |
General medical chemistry
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| Research Institution | Niigata University |
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Principal Investigator |
ONO Teruo Niigata University, School of Medicine, Professor, 医学部, 教授 (00000927)
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| Co-Investigator(Kenkyū-buntansha) |
KUMAGAI Hidetoshi Niigata University, School of Medicine, Research Associate, 医学部, 助手 (20281008)
SAKAKIBARA Jun Niigata University, School of Medicine, Research Associate, 医学部, 助手 (90242403)
FUJII Hiroshi Niigata University, School of Medicine, Associate Professor, 医学部, 助教授 (90165340)
星野 力 新潟大学, 農学部, 教授 (30165542)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥7,800,000 (Direct Cost: ¥7,800,000)
Fiscal Year 1997: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1996: ¥5,400,000 (Direct Cost: ¥5,400,000)
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| Keywords | squalene epoxidase / lanosterol synthase / cholesterol / transcriptional regulation / SREBP (sterol regulatory element binding protein) / NF-Y / transcription factor / membrane binding domain / 転写調整 / スクアレン・エポキシダーゼ(SE) / 遺伝子構造(イントロン-エクソン構成) / HeLa細胞 / 発現調節 / プロモーター領域 / 染色体8 / D8S508 |
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| Research Abstract |
Human squalene eposidase (SE) and lanosterol synthase (OSC) cDNAs were isolated using rat SE and rat OSC cDNAs as probes. SE genes also isolated from rat and human genomic libraries. We found the human SE gene consisted of 11 exons and located in the neighborhood of chromosome 8q telomere. Regulation of SE gene expression by sterol was studied in comparison with those of 3-hydroxy-3-methylglutaryl CoA reductases (HMG-CoA R) and low density lipoprotein receptor (LDLR). Results suggest that sterol produced endogenously can regulate SE expression at the level of transcription similar to HMG-CoA R and LDLR.Luciferase assay using 5'and 3'promoter deletion mutants determined two critical regions for regulation by sterols. Gelshift and overexpression assays showed that sterol regulatory element binding protein (SREBP) binds to critical region l and mediated the transcriptional regulation of SE gene. Another critical region contains NF-Y binding site.
The amino acid sequence of mammal SE reveals 5 transmembrane spanning domains including beta_1-alpha A-beta_2 motif of FAD binding domain. In contrast Saccharomyces cerevisiac, Schizosaccharomyces pombe and Candida albicans reveal 2 membrane spanning domains. These differences may reflect species specificity of SE inhibitors. Photoaffinity labeled analogues of substrate and its competitive inhibitors were found in two polypeptides of the DELTA^<100> N-terminal fragment (mw 12,000) including the highly conserved sequence I and the tripeptide very close to the highly conserved II,respectively. The results indicated that the higyly conserved I and II region may constitute three dimensional structure of substrate binding domain.
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