title: Molecular basis distinguishing the DNA binding profile of Nrf2-Maf heterodimer from that of Maf homodimer.
abstract: Nrf2-small Maf heterodimer activates the transcription of many cytoprotective genes through the antioxidant response element and serves as a key factor in xenobiotic and oxidative stress responses. Our surface plasmon resonance-microarray binding analysis revealed that both Nrf2-MafG heterodimer and MafG homodimer bind to the consensus Maf recognition element with high affinity but bind differentially to the suboptimal binding sequences degenerated from the consensus. We examined the molecular basis distinguishing the binding profile of Nrf2-MafG heterodimer from that of MafG homodimer and found that the Ala-502 residue in the basic region of Nrf2 is a critical determinant of its binding specificity. In Maf proteins, a tyrosine resides in the position corresponding to Ala-502 in Nrf2. We prepared a mutant Nrf2 molecule in which Ala-502 was replaced with tyrosine. In surface plasmon resonance-microarray analysis, heterodimer of Nrf2(A502Y) and MafG displayed a binding specificity similar to that of MafG homodimer. The target genes activated by mutant Nrf2(A502Y)-small Maf heterodimer were largely different, albeit with some overlap, from those activated by wild-type Nrf2-small Maf, indicating that the array of target genes regulated by Nrf2-small Maf heterodimer differs substantially from that regulated by Maf homodimer in vivo. These results suggest that the distinct DNA binding profile of Nrf2-Maf heterodimer is biologically significant for Nrf2 to function as a key regulator of cytoprotective genes. Our contention is supported that the differential DNA binding specificity between Maf homodimers and Nrf2-Maf heterodimers establishes the differential gene regulation by these dimer-forming transcription factors.
authors: Graduate School of Comprehensive Human Sciences and Center for Tsukuba Advanced Research Alliance, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, 305-8572; Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575.
authors: Momoko
authors: M
authors: Kimura
authors: Graduate School of Comprehensive Human Sciences and Center for Tsukuba Advanced Research Alliance, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, 305-8572.
authors: Tae
authors: T
authors: Yamamoto
authors: Graduate School of Comprehensive Human Sciences and Center for Tsukuba Advanced Research Alliance, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, 305-8572.
authors: Jianyong
authors: J
authors: Zhang
authors: Department of Stress Response Science, Hirosaki University School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562.
authors: Ken
authors: K
authors: Itoh
authors: Graduate School of Comprehensive Human Sciences and Center for Tsukuba Advanced Research Alliance, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, 305-8572; TOYOBO Co. Ltd. Biotechnology Frontier Project, 10-24 Toyo-Cho, Tsuruga, 914-0047.
authors: Motoki
authors: M
authors: Kyo
authors: TOYOBO Co. Ltd. Biotechnology Frontier Project, 10-24 Toyo-Cho, Tsuruga, 914-0047.
authors: Terue
authors: T
authors: Kamiya
authors: Research Center for Advance Science and Technology, University of Tokyo, Tokyo 153-8904.
authors: Hiroyuki
authors: H
authors: Aburatani
authors: Graduate School of Comprehensive Human Sciences and Center for Tsukuba Advanced Research Alliance, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, 305-8572.
authors: Fumiki
authors: F
authors: Katsuoka
authors: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577.
authors: Hirofumi
authors: H
authors: Kurokawa
authors: Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8572.
authors: Toshiyuki
authors: T
authors: Tanaka
authors: Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575; Environmental Response Project, Exploratory Research for Advanced Technology-Japan Science and Technology Corp. (ERATO-JST), Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan.
authors: Hozumi
authors: H
authors: Motohashi
authors: Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575; Environmental Response Project, Exploratory Research for Advanced Technology-Japan Science and Technology Corp. (ERATO-JST), Tohoku University Graduate School of Medicine, 2-1 Seiryo-cho, Aoba-ku, Sendai 980-8575, Japan. Electronic address: hozumim@mail.tains.tohoku.ac.jp.
authors: Masayuki
authors: M
authors: Yamamoto
mesh_terms: D000595:Amino Acid Sequence; D004247:DNA / Q000737:chemistry*; D019281:Dimerization; D005786:Gene Expression Regulation; D006801:Humans; D007700:Kinetics; D051259:MafG Transcription Factor / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D051267:NF-E2-Related Factor 2 / Q000737:chemistry* / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D011485:Protein Binding; D051257:Proto-Oncogene Proteins c-maf / Q000737:chemistry* / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D020349:Surface Plasmon Resonance; D014443:Tyrosine / Q000737:chemistry
chemical_list: C495607:MAF protein, human; C103944:MAFG protein, human; D051259:MafG Transcription Factor; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D051257:Proto-Oncogene Proteins c-maf; D012097:Repressor Proteins; D014443:Tyrosine; D004247:DNA