Proteomics analysis reveals the effect of Aeromonas hydrophila sirtuin CobB on biological functions

Our previous studies have profiled lysine acetylation and succinylation modifications in Aeromonas hydrophila protein and have found that CobB may be involved in lysine deacylation; however, its effects on bacterial biological function are still unknown. In this study, a data-independent acquisition (DIA)-based proteomics method was used to compare the protein abundance between cob-deleted mutants and wild-type strains. Of the total 2385 identified proteins, 385 were found to have increased abundance, while only 46 showed decreased abundance. Data analysis revealed that many proteins in six metabolic pathways, ribosome, the bacterial secretion system, protein export, RNA degradation, beta-Lactam resistance and oxidative phosphorylation, were affected by the deletion of cobB. Some proteins, such as outer membrane proteins, the two-component regulatory systems and transcriptional factor, were also regulated by cobB. The following phenotype assays confirmed that the ΔcobB mutant produced more biofilm, migrated farther in soft agar, and was more sensitive to oxidative stress than its WT parent. Taken together, the results presented herein provide insights into the behaviors of sirtuin protein CobB in bacteria and demonstrate its important biological functions in A. hydrophila. BIOLOGICAL SIGNIFICANCE: The sirtuin protein CobB play crucial roles on lysine deacylation, such as desuccinylation and deacetylation in many bacterial species, while the intrinsic behavior of CobB on bacteria remains elusive. The current DIA-based quantitative proteomics analysis showed that the deletion of A. hydrophila cobB significantly affect the intracellular biological processes. Further phenotype assays validated proteomics results. Overall, our data further confirmed the important roles of CobB on the complex protein-protein interaction network regulation in A. hydrophila.