Shigella flexneri invasion of HeLa cells induces NF-kappa B DNA-binding activity.
Although information about the genetic basis and mechanisms of Shigella flexneri cellular invasion is accumulating, little is known about changes in cell signaling and their consequences following bacterium-host cell interactions. A general result of signal transduction is alterations in the levels and/or activities of transcription factors. Alterations in transcription factor binding activities were observed following challenge with S. flexneri. Changes in the DNA-binding activities of cellular transcription factors to AP1, AP2, cyclic AMP response element, CTF1/NF1, NF-kappa B/Rel, OCT1, and SP1 DNA-binding sites were investigated by electrophoretic mobility shift assays. NF-kappa B/Rel DNA-binding activity was enhanced more than 11-fold by cellular invasion; noninvasive S. flexneri strains induced low levels of kappa B DNA binding. Both subunits of the NF-kappa B transcription factor, p50 and p65, but not c-Rel (p85), are components of the kappa B DNA-binding activity. These data suggest that changes in cellular transcription factor binding activity are a consequence of S. flexneri invasion, and these changes could play a role in the initial host response or in the pathogenesis of the disease.
Dyer
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RB
Department of Microbiology, University of Texas Medical Branch, Galveston 77555-0605.
Collaco
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Niesel
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Herzog
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D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism; D004405:Dysentery, Bacillary / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000737:chemistry / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D012045:Regulatory Sequences, Nucleic Acid; D012763:Shigella flexneri / Q000472:pathogenicity*; D014157:Transcription Factors / Q000378:metabolism
D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D016328:NF-kappa B; D009687:Nuclear Proteins; D009838:Oligodeoxyribonucleotides; D014157:Transcription Factors