Chemoproteomic Profiling Reveals the Mechanism of Bile Acid Tolerance in Bacteria

Biwei Liu, Shentian Zhuang, Runze Tian, Yuan Liu, Yanqi Wang, Xiaoguang Lei,* and Chu Wang* ACS Chemical Biology Article ASAP
DOI: 10.1021/acschembio.2c00286

Bile acids (BAs) are a class of endogenous metabolites with important functions. As amphipathic molecules, BAs have strong antibacterial effects, preventing overgrowth of the gut microbiota and defending the invasion of pathogens. However, some disease-causing pathogens can survive the BA stress and knowledge is limited about how they develop BA tolerance. In this work, we applied a quantitative chemoproteomic strategy to profile BAinteracting proteins in bacteria, aiming to discover the sensing pathway of BAs. Using a clickable and photo-affinity BA probe with quantitative mass spectrometry, we identified a list of histidine kinases (HKs) of the twocomponent systems (TCS) in bacteria as the novel binding targets of BA. Genetic screening revealed that knocking out one specific HK, EnvZ, renders bacteria with significant sensitivity to BA. Further biochemical and genetic
experiments demonstrated that BA binds to a specific pocket in EnvZ and activates a downstream signaling pathway to help efflux of BA from bacteria, resulting in BA tolerance. Collectively, our data revealed that EnvZ is a novel sensor of BA in bacteria and its associated TCS signaling pathway plays a critical role in mediating bacterial BA tolerance, which opens new opportunities to combat BA-tolerating pathogens.

Chemoproteomic Profiling Reveals the Mechanism of Bile Acid Tolerance in Bacteria，Biwei Liu, Shentian Zhuang, Runze Tian, Yuan Liu, Yanqi Wang, Xiaoguang Lei,* and Chu Wang* ACS Chemical Biology Article ASAP
DOI: 10.1021/acschembio.2c00286

Bile acids (BAs) are a class of endogenous metabolites with important functions. As amphipathic molecules, BAs have strong antibacterial effects, preventing overgrowth of the gut microbiota and defending the invasion of pathogens. However, some disease-causing pathogens can survive the BA stress and knowledge is limited about how they develop BA tolerance. In this work, we applied a quantitative chemoproteomic strategy to profile BAinteracting proteins in bacteria, aiming to discover the sensing pathway of BAs. Using a clickable and photo-affinity BA probe with quantitative mass spectrometry, we identified a list of histidine kinases (HKs) of the twocomponent systems (TCS) in bacteria as the novel binding targets of BA. Genetic screening revealed that knocking out one specific HK, EnvZ, renders bacteria with significant sensitivity to BA. Further biochemical and genetic
experiments demonstrated that BA binds to a specific pocket in EnvZ and activates a downstream signaling pathway to help efflux of BA from bacteria, resulting in BA tolerance. Collectively, our data revealed that EnvZ is a novel sensor of BA in bacteria and its associated TCS signaling pathway plays a critical role in mediating bacterial BA tolerance, which opens new opportunities to combat BA-tolerating pathogens.