title: Beyond antioxidant genes in the ancient Nrf2 regulatory network.
abstract: Nrf2, a basic leucine zipper transcription factor encoded by the gene NFE2L2, is a master regulator of the transcriptional response to oxidative stress. Nrf2 is structurally and functionally conserved from insects to humans, and it heterodimerizes with the small MAF transcription factors to bind a consensus DNA sequence (the antioxidant response element, or ARE) and regulate gene expression. We have used genome-wide chromatin immunoprecipitation and gene expression data to identify direct Nrf2 target genes in Drosophila and humans. These data have allowed us to construct the deeply conserved ancient Nrf2 regulatory network-target genes that are conserved from Drosophila to human. The ancient network consists of canonical antioxidant genes, as well as genes related to proteasomal pathways and metabolism and a number of less expected genes. We have also used enhancer reporter assays and electrophoretic mobility-shift assays to confirm Nrf2-mediated regulation of ARE activity at a number of these novel target genes. Interestingly, the ancient network also highlights a prominent negative feedback loop; this, combined with the finding that Nrf2-mediated regulatory output is tightly linked to the quality of the ARE it is targeting, suggests that precise regulation of nuclear Nrf2 concentration is necessary to achieve proper quantitative regulation of distinct gene sets. Together, these findings highlight the importance of balance in the Nrf2-ARE pathway and indicate that Nrf2-mediated regulation of xenobiotic metabolism, glucose metabolism, and proteostasis has been central to this pathway since its inception.
authors.affiliation: Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, USA.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Lacher
authors.affiliation: Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, USA.
authors.forename: Joslynn S
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Environmental Genomics Section, Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
authors.forename: Xuting
authors.initials: X
authors.lastname: Wang
authors.affiliation: Environmental Genomics Section, Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
authors.forename: Michelle R
authors.initials: MR
authors.lastname: Campbell
authors.affiliation: Environmental Genomics Section, Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA.
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Bell
authors.affiliation: Department of Biomedical Sciences, University of Minnesota Medical School, Duluth, MN 55812, USA; Developmental Biology Center, University of Minnesota, Minneapolis, MN 55455, USA. Electronic address: mslatter@umn.edu.
authors.forename: Matthew
authors.initials: M
authors.lastname: Slattery
mesh_terms: D000818:Animals; D061745:Antioxidant Response Elements / Q000235:genetics; D000975:Antioxidants / Q000378:metabolism; D001483:Base Sequence; D047369:Chromatin Immunoprecipitation; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics*; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D051267:NF-E2-Related Factor 2 / Q000235:genetics*; D010802:Phylogeny; D012097:Repressor Proteins / Q000235:genetics*; D059467:Transcriptome / Q000235:genetics*
chemical_list: D000975:Antioxidants; D029721:Drosophila Proteins; D051267:NF-E2-Related Factor 2; D012097:Repressor Proteins; C116463:cnc protein, Drosophila
keywords: ARE; Drosophila; Enhancer; Free radicals; Genomics; Human; Keap1; Nrf2; Transcriptional regulation