Résumé
Objective To investigate the role of protein phosphorylation in Pseudomonas aeruginosa (P.aeruginosa) strains in response to stress triggered by mouse macrophages.Methods The strong cation exchange-immobilized metal affinity chromatography (SCX-IMAC) was performed to enrich phosphopeptides.The nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS) was carried out to identify and analyze phosphoproteome.Results Fourteen phosphopeptides from twelve proteins were identified within thirty-one phosphorylation sites on serine,threonine and tyrosine residues.Fifty percent of these phosphorylated proteins were membrane proteins,indicating that their phosphorylation modification was more critical for bacteria in response to the stress.In terms of biological process of Gene Ontology,these identified proteins were involved in stress response,iron transport,anaerobic respiration,response to hydrogen peroxide and signal transduction by phosphorylation,etc.Conclusion These phosphorylated proteins in P.aeruginosa strains are necessary for signal transduction and their response to harsh environment within the macrophages,such as iron limitation,hypoxia and oxidative stress.This study provides evidence for further investigation on virulence and pathogenesis of P.aeruginosa.