title: Characterization of DegU, a response regulator in Listeria monocytogenes, involved in regulation of motility and contributes to virulence.
abstract: The degU (lmo2515) gene encodes a putative response regulator in the food-borne pathogen Listeria monocytogenes. It has 63% amino acid identity to the DegU response regulator of Bacillus subtilis. We have characterized the degU gene product in L. monocytogenes EGD by generation of a deletion mutant. The DeltadegU mutant was found to be non-motile in motility plate assay and no flagellin was detected. The mutant was attenuated in challenge of mice. Northern blot analysis suggested that the degU gene product is a transcriptional activator of the flagellin gene, flaA, at 25 degrees C. However, the degU gene product had no influence on the transcription of prfA encoding the major virulence regulator, PrfA. The results indicate that the putative DegU response regulator is a pleiotropic regulator involved in expression of both motility at low temperature and in vivo virulence in mice.
authors.affiliation: Department of Veterinary Pathobiology and Centre for Advanced Food Studies, The Royal Veterinary and Agricultural University, Stigbøjlen 4, DK-1870 Frederiksberg C, Denmark.
authors.forename: Gitte M
authors.initials: GM
authors.lastname: Knudsen
authors.forename: John E
authors.initials: JE
authors.lastname: Olsen
authors.forename: Lone
authors.initials: L
authors.lastname: Dons
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D001483:Base Sequence; D004195:Disease Models, Animal; D005260:Female; D005408:Flagellin / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005809:Genes, Regulator; D008089:Listeria monocytogenes / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009068:Movement; D010454:Peptide Termination Factors; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation
chemical_list: D001426:Bacterial Proteins; C066497:DegU protein, Bacteria; D010454:Peptide Termination Factors; D015534:Trans-Activators; D005408:Flagellin; C067138:flaA protein, bacteria