title: Transient overexpression of catalase does not inhibit TNF- or PMA-induced NF-kappa B activation.
abstract: H2O2 has been proposed as a second messenger involved in cell signaling for NF-kappa B activation. In the present study, this hypothesis was tested by transiently overexpressing catalase, a specific scavenger of H2O2, in COS-1 cells. A mammalian expression vector was constructed by incorporating catalase gene from pCAT10 clone into the unique EcoRI site of the pSG5 vector which contains the SV-40 promoter. Transient transfection of the catalase expression vector by the DEAE-dextran method led to a four-fold increase in catalase activity and catalase content as detected by immunoblot analysis. This level of increase was detected in both nuclear/mitochondrial- and cytosolic/microsomal fractions. Overexpression of catalase, however, did not block TNF- or PMA-induced NF-kappa B activation. These results weaken the hypothesis that H2O2 is a second messenger for TNF- and PMA-signaling for NF-kappa B activation.
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: L
authors.initials: L
authors.lastname: Packer
mesh_terms: D000818:Animals; D001483:Base Sequence; D002374:Catalase / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D015870:Gene Expression; D006861:Hydrogen Peroxide / Q000378:metabolism; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides; D015398:Signal Transduction; D013755:Tetradecanoylphorbol Acetate / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000494:pharmacology*
chemical_list: D016328:NF-kappa B; D009838:Oligodeoxyribonucleotides; D014409:Tumor Necrosis Factor-alpha; D006861:Hydrogen Peroxide; D002374:Catalase; D013755:Tetradecanoylphorbol Acetate