title: Nrf2 activation is associated with Z-DNA formation in the human HO-1 promoter.
abstract: Using a luciferase reporter assay, we previously demonstrated that a Z-DNA-forming sequence of alternating thymine-guanine repeats in the human heme oxygenase-1 gene (HO-1) promoter is involved in nuclear factor erythroid-derived 2 (NF-E2)-related factor 2 (Nrf2)-mediated HO-1 promoter activation. However, the actual Z-DNA formation in this native genomic locus has not been experimentally demonstrated. To detect Z-DNA formation in vivo, we generated a construct containing the Z-DNA-binding domain of human adenosine deaminase acting on double-stranded RNA 1 fused with enhanced green fluorescence protein, designated as the Z-probe. A chromatin immunoprecipitation assay using an anti-GFP antibody showed that the Z-probe detects the well-characterized Z-DNA formation in the CSF1 promoter. Using this detection system, we demonstrated that the glutathione-depleting agent, diethyl maleate, induced Nrf2-dependent Z-DNA formation in the HO-1 promoter, but not in the thioredoxin reductase 1 gene promoter. Moreover, a time course analysis revealed that Z-DNA formation precedes HO-1 transcriptional activation. Concurrent with Z-DNA formation, nucleosome occupancy was reduced, and the recruitment of RNA polymerase II was enhanced in the HO-1 promoter region, suggesting that Z-DNA formation enhances HO-1 gene transcription. Furthermore, Nrf2-induced BRG1 recruitment to the HO-1 promoter temporarily occurred simultaneously with Z-DNA formation. Thus, these results implicate Nrf2-dependent Z-DNA formation in HO-1 transcriptional activation and suggest the involvement of BRG1 in Z-DNA formation.
authors.affiliation: Department of Stress Response Science, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Maruyama
authors.forename: Junsei
authors.initials: J
authors.lastname: Mimura
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Harada
authors.forename: Ken
authors.initials: K
authors.lastname: Itoh
mesh_terms: D002460:Cell Line; D043542:DNA, Z-Form / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000032:analysis; D051547:Heme Oxygenase-1 / Q000235:genetics*; D006801:Humans; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics; D008298:Maleates / Q000494:pharmacology; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D015533:Transcriptional Activation
chemical_list: D043542:DNA, Z-Form; D008298:Maleates; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D016173:Macrophage Colony-Stimulating Factor; C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1; C014476:diethyl maleate