Lightning Talk & Poster 27th Annual Lorne Proteomics Symposium 2022

An emerging role for protein lysine acetylation during in vivo-like growth in Campylobacter jejuni (#39)

Ashleigh L Dale 1 2 , Lok Man 1 2 , Melanie White 2 3 , Stuart J Cordwell 1 2 4
  1. School of Life and Environmental Sciences, University of Sydney, Sydney
  2. Charles Perkins Center, Sydney, NSW, Australia
  3. Discipline of Pathology, School of Medical Sciences, University of Sydney, Sydney
  4. Sydney Mass Spectrometry, University of Sydney, Sydney, NSW, Australia

Campylobacter jejuni is the leading cause of acute bacterial gastroenteritis in the developed world, however the biochemical mechanisms of pathogenesis remain poorly understood. Lysine acetylation (K-Ac) is a reversible post-translational modification that can alter in vivo protein structure / function. A combination of acetyl-lysine immunoprecipitation and two-dimensional liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) identified 5,569 acetylated lysines on 1,026 C. jejuni proteins (~63% of the predicted proteome). Functional enrichment confirmed acetylated proteins are involved in central metabolism, stress responses, translation and transcription, chemotaxis, gluconeogenesis and the TCA cycle. Label-based LC-MS/MS quantified acetylated peptides during growth in sodium deoxycholate (DOC, a component of gut bile salts), chicken exudate and mucin. A total of 1,445 proteins and 3,571 K-Ac peptides were quantified, and the most profound shift at the protein and acetylation level was as a result of DOC treatment. A total of 761 K-Ac peptides from 403 proteins were differentially regulated in response to DOC, the majority exhibiting an increase in abundance in K-Ac levels. These protein changes were involved in a number of metabolic pathways and processes, suggesting a dynamic role for K-Ac in bile resistance. We hypothesise a role for the acetogenesis/acetate utilisation pathway in protein acetylation and confirm K-Ac affects the stability of the major C. jejuni adhesin, CadF. This work provides the first system-wide interrogation and analysis of the lysine acetylome of C. jejuni and contributes to our understanding of acetylation as an emerging post-translational modification of interest in bacteria.