1999 Fiscal Year Final Research Report Summary
Identification of transcription factor related to toxicity of dioxin
| Project/Area Number |
10672117
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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 |
Environmental pharmacy
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| Research Institution | National Institute for Environmental Studies |
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Principal Investigator |
AOKI Yasunobu National Institute for Environmental Studies, Environmental Health Science Division, Section Chief, 環境健康部・病態機構研究室, 室長 (20159297)
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| Co-Investigator(Kenkyū-buntansha) |
IMAGAWA Masayoshi Graduate School of Pharmaceutical Sciences Osaka University, Associate Professor, 大学院・薬学研究科, 助教授 (20136823)
MATSUMOTO Michi National Institute for Environmental Studies, Environmental Health Science Division, Senior Research Scientist, 環境健康部・病態機構研究室, 主任研究員 (60132867)
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| Project Period (FY) |
1998 – 1999
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| Keywords | coplanar PCB / 33'44'5-pemtachlorobiphenyl / pi-class glutathione S-transferase / rat liver parenchymal / CAT assay / GPEI / uv-cross-link / antioxidant responsive element |
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| Research Abstract |
2378-tetrachlorodibenzo-p-dioxin (dioxin) and related compounds exert various toxicities such as teratogenicity and tumor promoting activity, but the mechanisms of gene expression accompanied with emerge of their toxic effect remain to be unclear. Previously, we showed that 3453'4'-pentachlorobiphenyl (PenC) a dioxin related compound, induces the expression of pi class glutathione S-transferase (GSTP1) gene in primary cultured rat liver parenchymal cells.
In order to understand the regulation of GSTP1 gene expression, a regulatory element on 5' flanking sequence of this gene was identified by CAT assay. The GPEI element was shown to be required for stimulation of GSTP1 gene expression by PenCB in primary cultured liver parenchymal cells. GPEI is already known to contain a dyad of phorbol ester responsive element-like elements oriented palindromically. It is suggested that a novel signal transduction pathway activated by PenCB contributes to stimulation of GSTP1 expression.
Not only PenCB but epidermal growth factor (EGF) induces the expression of GSTP1 gene. GPEI element is also required for the expression of this gene by EGF and TGFα. It is suggested that EGF and TGFα induce GSTP1 by the same signal transduction pathway as PenCB.
We intend now to identify the GPEI binding protein using a nuclear extract of immortalized rat liver parenchymal cells which constitutively express GSTP1 as a starting material. GPEI binding proteins in the nucleous were cross-linked with 32P labeled GPEI oligomer by UV irradiation and were separated by 2D gel electrophoresis. Proteins bound to GPEI oligomer were isolated after detecting by autoradiography. After determining the molecular weights of triptic digests of isolated proteins by MALDI-TOF/MS, we have identified the GPEI binding proteins referring with the data base of protein sequences.
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Research Products
(2 results)
