First Author | Duh JL | Year | 1995 |
Journal | J Biol Chem | Volume | 270 |
Issue | 51 | Pages | 30499-507 |
PubMed ID | 8530481 | Mgi Jnum | J:30335 |
Mgi Id | MGI:77847 | Doi | 10.1074/jbc.270.51.30499 |
Citation | Duh JL, et al. (1995) The Y-box motif mediates redox-dependent transcriptional activation in mouse cells. J Biol Chem 270(51):30499-507 |
abstractText | We show here that the OxyR response element (ORE) in the bacterial oxyR promoter can also function as a redox-dependent enhancer in mammalian cells. Fusion of ORE to an SV40 basal promoter driving chloramphenicol acetyltransferase (CAT) expression confers H2O2 inducibility to expression of the cat gene in mouse Hepa-1 hepatoma cells. Nuclear extracts from these cells contain DNA-binding proteins that specifically interact with ORE DNA, cannot be completed by cognate oligonucleotides to AP-1 or NF kappa B, and are constitutively expressed, since treatment with H2O2 causes no detectable changes in binding activity or DNA-protein interaction. Recombinant cDNA clones that express ORE-binding proteins were isolated from a mouse hepatoma expression library and found to be representatives of two different members of the murine Y-box family of transcription factors. Canonical Y-box and ORE oligonucleotides compete with each other for binding to Y-box proteins in gel shift assays and antibodies to FRGY2, a Xenopus Y-box protein, supershift both Y-box and ORE DNA-protein complexes. In addition, antisense oligonucleotides to mouse YB-1 mRNA abolish induction of ORE-mediated cat expression by H2O2, and luciferase reporter constructs containing ORE, or the Y-box from the human MHC class II HLA-DQ gene, exhibit identical dose-dependent H2O2 inducibilities, which can be abolished by addition of 2-mercaptoethanol to the culture medium. These results suggest that the Y-box proteins may be an integral component of a eukaryotic redox signaling pathway. |