Chemical probes unravel an antimicrobial defense response triggered by binding of the human opioid dynorphin to a bacterial sensor kinase
ABSTRACT: Host-microbe communication via small molecule signals is often poorly understood at the molecular level. Under conditions of host stress, levels of the human opioid peptide dynorphin are elevated, triggering virulence in the opportunistic pathogenic bacterium Pseudomonas aeruginosa (PAO1) via an unknown pathway. Here we apply multiple chemical biology strategies to unravel the mode of action of this putative interkingdom signal. We designed and applied dynorphin-inspired photoaffinity probes (DYN4 and DYN5) to reveal the protein targets of the peptide in live bacteria via chemical proteomics. Sensor kinase ParS was identified as a potential hit. Subsequent full proteome studies revealed that dynorphin(1-13) (DYN) induces an antimicrobial peptide-like response in Pseudomonas, with specific upregulation of membrane defence mechanisms (datasets Stat.10 and Exp.5). No such response was observed in a parS mutant (Stat.1), functionally linking DYN engagement with ParS to this phenotype.
Journal of the American Chemical Society 20170420 17
Host-microbe communication via small molecule signals is important for both symbiotic and pathogenic relationships, but is often poorly understood at the molecular level. Under conditions of host stress, levels of the human opioid peptide dynorphin are elevated, triggering virulence in the opportunistic pathogenic bacterium Pseudomonas aeruginosa via an unknown pathway. Here we apply a multilayered chemical biology strategy to unravel the mode of action of this putative interkingdom signal. We d ...[more]
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