Today, it is well known that proteins can play diverse functions on short timescales, due to post- translational modifications (PTMs). In contrast to eukaryotes, PTM discovery in bacteria is quite recent. Different modifications have been described in bacteria, like the addition of chemical groups on the side chain of specific amino acids (phosphorylation, acetylation, succinylation…). Their roles on bacterial physiology or virulence are increasingly described and their characterization are thus essential to a better understanding of the molecular mechanisms.
Proteomics analyses have revolutionized PTMs characterization thanks to mass spectrometry and analytical separation improvements, bioinformatics tools and antibody development. However, their characterizations are still a challenge for different issues like the low abundance of modified proteins, and the lack of specific antibodies… We will present here different strategies to characterize PTMs in Pseudomonas aeruginosa, one of the major human opportunistic pathogen largely involved in nosocomial infections and responsible of a variety of diseases in weakened individuals. We will mainly focus on two lysine modifications, i.e., acetylation and succinylation, and will show their involvement in P. aeruginosa physiology.