Characterization of the bvgR Locus of Bordetella pertussis
AUTOR(ES)
Merkel, Tod J.
FONTE
American Society for Microbiology
RESUMO
Bordetella pertussis, the causative agent of whooping cough, produces a wide array of factors that are associated with its ability to cause disease. The expression and regulation of these virulence factors is dependent upon the bvg locus (originally designated the vir locus), which encodes two proteins: BvgA, a 23-kDa cytoplasmic protein, and BvgS, a 135-kDa transmembrane protein. It is proposed that BvgS responds to environmental signals and interacts with BvgA, a transcriptional regulator which upon modification by BvgS binds to specific promoters and activates transcription. An additional class of genes is repressed by the bvg locus. Expression of this class, the bvg-repressed genes (vrgs [for vir-repressed genes]), is reduced under conditions in which expression of the aforementioned bvg-activated virulence factors is maximal; this repression is dependent upon the presence of an intact bvgAS locus. We have previously identified a locus required for regulation of all of the known bvg-repressed genes in B. pertussis. This locus, designated bvgR, maps to a location immediately downstream of bvgAS. We have undertaken deletion and complementation studies, as well as sequence analysis, in order to identify the bvgR open reading frame and identify the cis-acting sequences required for regulated expression of bvgR. Studies utilizing transcriptional fusions of bvgR to the gene encoding alkaline phosphatase have demonstrated that bvgR is activated at the level of transcription and that this activation is dependent upon an intact bvgAS locus.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=107078Documentos Relacionados
- Analysis of bvgR Expression in Bordetella pertussis
- Identification of a locus required for the regulation of bvg-repressed genes in Bordetella pertussis.
- Contribution of Regulation by the bvg Locus to Respiratory Infection of Mice by Bordetella pertussis
- Characterization of DNA binding sites for the BvgA protein of Bordetella pertussis.
- BvgAS is sufficient for activation of the Bordetella pertussis ptx locus in Escherichia coli.