Proteomic profiling of the Pseudomonas aeruginosa stringent response highlights global adaptive responses during stationary phase.

Proteomic profiling reveals that the (p)ppGpp-mediated stringent response in Pseudomonas aeruginosa regulates over 300 proteins during stationary phase, emphasizing its role in stress adaptation.

• Why it matters: Understanding how P. aeruginosa adapts to stressful environments is crucial for developing treatments against infections, as the pathogen's resilience is partly driven by the stringent response.
• What they did: The study used shotgun proteomics (LC-MS/MS) to compare a (p)ppGpp-null relA spoT mutant with wild-type PAO1 during late exponential and stationary phases, identifying 146 and 339 differentially abundant proteins, respectively.
• The result: Findings demonstrate that (p)ppGpp orchestrates broad metabolic shutdown and activates stress responses, with evidence of post-transcriptional regulation via small RNAs, offering insights into bacterial survival strategies.