The Transcriptional Regulator BpsR Controls the Growth of Bordetella bronchiseptica by Repressing Genes Involved in Nicotinic Acid Degradation
| Autor: | Thomas Hollis, Manita Guragain, Mary E. Finger, Rajendar Deora, Natalia Cattelan, Matt S. Conover, Jamie Jennings-Gee |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Transcription Genetic Bordetella 030106 microbiology Bordetella bronchiseptica Microbiology Niacin 03 medical and health sciences Bacterial Proteins Genes Regulator Transcriptional regulation Inducer transcriptional regulation Molecular Biology Gene Ciencias Exactas biology Base Sequence Biofilm Promoter Gene Expression Regulation Bacterial biology.organism_classification Biochemistry metabolism Bacteria Gene Deletion Research Article |
| Zdroj: | SEDICI (UNLP) Universidad Nacional de La Plata instacron:UNLP |
| ISSN: | 1098-5530 |
| Popis: | Many of the pathogenic species of the genus Bordetella have an absolute requirement for nicotinic acid (NA) for laboratory growth. These Gram-negative bacteria also harbor a gene cluster homologous to the nic cluster of Pseudomonas putida which is involved in the aerobic degradation of NA and its transcriptional control. We report here that BpsR, a negative regulator of biofilm formation and Bps polysaccharide production, controls the growth of Bordetella bronchiseptica by repressing the expression of nic genes. The severe growth defect of the ΔbpsR strain in Stainer-Scholte medium was restored by supplementation with NA, which also functioned as an inducer of nic genes at low micromolar concentrations that are usually present in animals and humans. Purified BpsR protein bound to the nic promoter region, and its DNA binding activity was inhibited by 6-hydroxynicotinic acid (6-HNA), the first metabolite of the NA degradative pathway. Reporter assays with the isogenic mutant derivative of the wild-type (WT) strain harboring deletion in nicA, which encodes a putative nicotinic acid hydroxylase responsible for conversion of NA to 6-HNA, showed that 6-HNA is the actual inducer of the nic genes in the bacterial cell. Gene expression profiling further showed that BpsR dually activated and repressed the expression of genes associated with pathogenesis, transcriptional regulation, metabolism, and other cellular processes. We discuss the implications of these findings with respect to the selection of pyridines such as NA and quinolinic acid for optimum bacterial growth depending on the ecological niche. Centro de Investigación y Desarrollo en Fermentaciones Industriales |
| Databáze: | OpenAIRE |
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