Proteome dynamics in persisting and resuscitating bacterial cells
During antibiotic persistence, bacterial cells become transiently tolerant to antibiotics by restraining their growth and metabolic activity. Detailed molecular characterization of antibiotic persistence is hindered by low count of persisting cells and the need for their isolation. Here we used sustained addition of stable isotope-labeled lysine to selectively label the proteome during hipA-induced persistence and hipB-induced resuscitation of E. coli cells in minimal medium after antibiotic treatment. Time-resolved, 24-hour measurement of label incorporation allowed detection of over 500 newly synthesized proteins in viable cells, demonstrating low but widespread protein synthesis during persistance. Many essential proteins were newly synthesized and several ribosome-associated proteins, such as RaiA and Sra showed high synthesis levels, pointing to their roles in maintenance of persistence. At the onset of resuscitation, cells synthesized the ribosome-splitting GTPase HflX and various ABC transporters, restored translation machinery and resumed metabolism by inducing glycolysis and biosynthesis of amino acids.