title: Pi class glutathione S-transferase genes are regulated by Nrf 2 through an evolutionarily conserved regulatory element in zebrafish.
abstract: Pi class GSTs (glutathione S-transferases) are a member of the vertebrate GST family of proteins that catalyse the conjugation of GSH to electrophilic compounds. The expression of Pi class GST genes can be induced by exposure to electrophiles. We demonstrated previously that the transcription factor Nrf 2 (NF-E2 p45-related factor 2) mediates this induction, not only in mammals, but also in fish. In the present study, we have isolated the genomic region of zebrafish containing the genes gstp1 and gstp2. The regulatory regions of zebrafish gstp1 and gstp2 have been examined by GFP (green fluorescent protein)-reporter gene analyses using microinjection into zebrafish embryos. Deletion and point-mutation analyses of the gstp1 promoter showed that an ARE (antioxidant-responsive element)-like sequence is located 50 bp upstream of the transcription initiation site which is essential for Nrf 2 transactivation. Using EMSA (electrophoretic mobility-shift assay) analysis we showed that zebrafish Nrf 2-MafK heterodimer specifically bound to this sequence. All the vertebrate Pi class GST genes harbour a similar ARE-like sequence in their promoter regions. We propose that this sequence is a conserved target site for Nrf 2 in the Pi class GST genes.
authors.affiliation: ERATO-JST and Institute of Basic Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Laboratory of Advanced Research D, Tsukuba 305-8577, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Yaeko
authors.initials: Y
authors.lastname: Takagi
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Osanai
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Miki
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Yasutake
authors.initials: Y
authors.lastname: Katoh
authors.forename: Makoto
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamamoto
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D019143:Evolution, Molecular; D005786:Gene Expression Regulation; D005982:Glutathione Transferase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D050436:Regulatory Elements, Transcriptional; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish
chemical_list: D005982:Glutathione Transferase