Retrovirus-mediated transfer of nuclear factor-kappa B subunit genes modulates I kappa B alpha and interferon beta expression.
Nuclear factor (NF)-kappa B proteins regulate the transcription of numerous genes involved in the immune response, transcription control, and viral pathogenesis. To examine the effect of ectopic expression of NF-kappa B proteins on DNA-binding activity and gene expression, individual NF-kappa B subunit genes were introduced into NIH 3T3 cells via retrovirus-mediated gene transfer. Expression of NF-kappa B subunits RelA (p65), NF-kappa B1 (p105), NF-kappa B2 (p100), and c-Rel increased the basal level of nuclear NF-kappa B DNA binding in NIH 3T3 cells, whereas expression of delta RelA (p65 delta) and NF-kappa B2 (p52) subunits did not affect basal level activity. Tumor necrosis factor-alpha treatment of the NF-kappa B-expressing cells stimulated the induced level of DNA-binding activity, reflecting interaction between endogenous murine and transfected human NF-kappa B proteins. Interestingly, expression of RelA (p65), c-Rel, NF-kappa B1 (p105), NF-kappa B2 (p100), and NF-kappa B2 (p52) subunits increased I kappa B alpha protein levels from 3- to 30-fold, indicating that one mechanism to compensate for the increased expression of NF-kappa B proto-oncogenes was to increase the synthesis and/or stability of the regulatory I kappa B alpha protein. In addition, overexpression of RelA (p65), c-Rel, NF-kappa B2 (p100), and NF-kappa B2 (p52) altered the induction kinetics of IFN-beta mRNA after Sendai virus infection, whereas overexpression of NF-kappa B1 (p105) dramatically decreased IFN-beta mRNA induction.
Terry Fox Molecular Oncology Group, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec, Canada.
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Bitar
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Beauparlant
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Pitha
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D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D018014:Gene Transfer Techniques; D006801:Humans; D020672:I-kappa B Proteins; D016899:Interferon-beta / Q000096:biosynthesis*; D051379:Mice; D008969:Molecular Sequence Data; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000235:genetics*; D012190:Retroviridae / Q000235:genetics*
D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; C000606205:Nfkbia protein, mouse; D000072000:NF-KappaB Inhibitor alpha; D016899:Interferon-beta