| Project/Area Number |
58060002
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| Research Category |
Grant-in-Aid for Specially Promoted Research
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| Allocation Type | Single-year Grants |
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| Research Institution | Institute for Protein Research, Osaka University |
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Principal Investigator |
SATO Ryo Professor, Institute for Protein Research, Osaka University, 蛋白質研究所, 教授 (00029927)
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| Co-Investigator(Kenkyū-buntansha) |
MIHARA Katsuyoshi Assistant Professor, Graduate School of Medical Science, Kyushu University, 医学系研究科分子生命科学専攻, 助教授 (40029963)
IMAI Yoshio Assistant Professor, Institute for Protein Research, Osaka University, 蛋白質研究所, 助教授 (60029949)
FUJII-KURIYAMA Yoshiaki Division Head, Cancer Institute, Japanese Foundation for Cancer Research, 部長 (00098146)
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| Project Period (FY) |
1983 – 1986
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| Keywords | Cytochrome P-450 / Molecular Multiplicity / cDNA / Regulation of Gene Expression / Enzyme Induction / 酵素誘導 |
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| Research Abstract |
Multiple forms of cytochrome P-450 occur in liver microsomes and administration of various drugs to animals leads to the induction of a specific form or forms of cytochrome P-450. This project was undertaken to elucidate the biochemical and genetic bases of this multiplicity of mammalian cytochrome P-450. The major results obtained in this project may be summarized as follows. First, 15 forms of cytochrome P-450 were purified from liver microsomes of untreated and variously drug-treated rabbits and their properties were examined in detail. Secondly, 16 cDNA clones including 8 full-length ones coding for different forms of rat and rabbit liver microsomal cytochrome P-450 were isolated and their nucleotide sequences determined. Comparison of their deduced primary structures and those determined in other laboratories leads to the conclusion that the mammalian P-450 gene superfamily consists of at least 5 families and some of the families are further classified into several subfamilies. Furthermore, microheterogeneity can be detected in the major phenobarbital-inducible form in rabbit liver. Thirdly, 4 rat P-450 genes, 1 rabbit P-450 gene and 2 human adrenal cortex P-450 genes were cloned and their structures were determined. In the rat P-450c gene three elements regulating its expression were detected in its 5' upstream region and one of them was identified as an enhancer involved in drug-mediated expression. Finally, Rat P-450d and a rabbit P-450 were successfully expressed in yeast cells. The P-450 proteins thus isolated from yeast cells were found to show relatively broad substrate specificities in spite of the fact that these P-450 proteins are homogeneous with respect to primary structure.
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