| Autor: |
Samuels DS; Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA., Lybecker MC; Department of Biology, University of Colorado, Colorado Springs, CO 80918, USA., Yang XF; Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA., Ouyang Z; Department of Molecular Medicine, University of South Florida, Tampa, FL 33612, USA., Bourret TJ; Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE, 68105 USA., Boyle WK; Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE, 68105 USA., Stevenson B; Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky School of Medicine, Lexington, KY 40536, USA., Drecktrah D; Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA., Caimano MJ; Departments of Medicine, Pediatrics, and Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA. |
| Abstrakt: |
Borrelia ( Borreliella ) burgdorferi , along with closely related species, is the etiologic agent of Lyme disease. The spirochete subsists in an enzootic cycle that encompasses acquisition from a vertebrate host to a tick vector and transmission from a tick vector to a vertebrate host. To adapt to its environment and persist in each phase of its enzootic cycle, B. burgdorferi wields three systems to regulate the expression of genes: the RpoN-RpoS alternative sigma factor cascade, the Hk1/Rrp1 two-component system and its product c-di-GMP, and the stringent response mediated by Rel Bbu and DksA. These regulatory systems respond to enzootic phase-specific signals and are controlled or fine- tuned by transcription factors, including BosR and BadR, as well as small RNAs, including DsrABb and Bb6S RNA. In addition, several other DNA-binding and RNA-binding proteins have been identified, although their functions have not all been defined. Global changes in gene expression revealed by high-throughput transcriptomic studies have elucidated various regulons, albeit technical obstacles have mostly limited this experimental approach to cultivated spirochetes. Regardless, we know that the spirochete, which carries a relatively small genome, regulates the expression of a considerable number of genes required for the transitions between the tick vector and the vertebrate host as well as the adaptation to each. |
