The two-component system PrrBA and NtrYX regulate the adaptation of Brucella to low oxygen tension

CARRICA M; FERNANDEZ I; PARIS G; FERNANDO A. GOLDBAUM

Mendosa

Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2012

Brucella is the causative agent of the zoonotic disease brucellosis, which is endemic in many parts of the world. The success of Brucella as pathogen resides in its ability to adapt to the harsh environmental conditions found in mammalians host. One of its main adaptations is the induction of the expression of different genes involved in respiration at low oxygen tension. We describe a regulatory network involved in this adaptation. We show that in Brucella abortus the two-component system PrrBA regulates the expression of the two-component system NtrYX, which is involved in redox sensing, and the transcriptional regulators FnrR and NnrA, which are involved in oxygen and nitric oxide sensing, respectively. We also show that PrrBA and NtrYX coordinately regulate the expression of denitrification and high-affinity cytochrome oxidase genes. Strikingly, a double mutant strain in prrB and ntrY genes is severely impaired in growth and virulence, while the ntrY and prrB single mutant strains are not. The regulatory network proposed could contribute to shed light into the mechanisms used by Brucella for a successful adaptation to its replicative niche inside mammalians cells.