title: Redox regulation of NF-kappa B DNA binding activity by dihydrolipoate.
abstract: NF-kappa B transcription factor regulates a wide variety of cellular and viral genes including the human immunodeficiency virus type 1. Here, we demonstrate that dihydrolipoate/alpha-lipoate redox couple which is a cofactor for mitochondrial dehydrogenases reactions, influences the DNA binding activity of NF-kappa B. The elimination of dithiothreitol in the electrophoretic mobility shift assay protocol resulted in the inability to detect DNA binding activity of activated NF-kappa B. The DNA binding activity was restored by the addition of dihydrolipoate in the binding reaction mixture. Inhibition of NF-kappa B DNA binding activity by in vitro exposure to a sulfhydryl oxidizing agent, diamide was also blocked by dihydrolipoate. In contrast, the addition of the oxidized form, alpha-lipoate inhibited the NF-kappa B DNA binding activity. Coincidentally, preincubation of Jurkat cells with dihydrolipoate potentiated and alpha-lipoate inhibited the okadaic acid-induced NF-kappa B activation as detected by assessing its DNA binding activity. These results suggest the redox exchange between lipoate and NF-kappa B molecules. Furthermore, since the inhibition of AP-1 DNA binding activity by diamide was also blocked by dihydrolipoate, this natural reductant may participate in the redox regulation of transcription factors by enhancing the DNA-protein interactions.
authors.affiliation: Department of Molecular & Cell Biology, University of California, Berkeley 94720, USA.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Mizuno
authors.forename: H J
authors.initials: HJ
authors.lastname: Tritschler
authors.forename: L
authors.initials: L
authors.lastname: Packer
mesh_terms: D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D015342:DNA Probes; D003958:Diamide / Q000494:pharmacology; D004229:Dithiothreitol / Q000494:pharmacology; D004988:Ethers, Cyclic / Q000494:pharmacology; D006801:Humans; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D019319:Okadaic Acid; D010084:Oxidation-Reduction; D008063:Thioctic Acid / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D015342:DNA Probes; D004988:Ethers, Cyclic; D016328:NF-kappa B; D018808:Transcription Factor AP-1; D014409:Tumor Necrosis Factor-alpha; D003958:Diamide; D019319:Okadaic Acid; D008063:Thioctic Acid; C015144:dihydrolipoic acid; D004247:DNA; D004229:Dithiothreitol