Oral Presentation 24th Annual Lorne Proteomics Symposium 2019

Proteomics reveals multiple phenotypes associated with N-linked glycosylation in Campylobacter jejuni (#48)

Joel A Cain 1 2 , Ashleigh L Dale 1 2 , Paula Niewold 2 3 , William P Klare 1 2 , Lok Man 1 2 , Melanie Y White 2 3 , Nichollas E Scott 1 4 , Stuart J Cordwell 1 2 3 5
  1. School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
  2. Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
  3. Discipline of Pathology, University of Sydney, Sydney, NSW, Australia
  4. Department of Microbiology and Immunology, The University of Melbourne, Melbourne, Victoria, Australia
  5. Sydney Mass Spectrometry, University of Sydney, Sydney, NSW, Australia

Campylobacter jejuni is the leading cause of acute gastroenteritis, and is typically acquired via consumption of undercooked poultry. N-linked protein glycosylation encoded by the pgl gene cluster targets >80 membrane proteins and is required for both non-symptomatic chicken colonization and full human intestinal epithelial cell virulence. Despite this, the biological functions of N-glycosylation remain unknown. Here we examined the effects of pgl gene deletion on the C. jejuni proteome using label-based liquid chromatography / tandem mass spectrometry (LC-MS/MS), quantifying 1359 C. jejuni proteins. Data independent analysis (DIA-SWATH-MS) was also employed to validate changes to 1080 proteins. Deletion of the pglB oligosaccharyltransferase (ΔpglB) resulted in a significant change in abundance of 185 proteins, with 137 restored by the reintroduction of pglB (ΔpglB::pglB). Loss of pglB was associated with significantly reduced abundances of known pgl targets and increased levels of stress-related proteins, including ClpB, GroEL, GroES, GrpE and DnaK. pglB mutants demonstrated reduced survival following temperature and osmotic shock, and showed altered biofilm phenotypes compared to wild-type C. jejuni. Finally, targeted metabolomics established that loss of N-glycosylation resulted in significant alterations to the C. jejuni metabolome, including changes in amino acid and carbon source preferences and disruption of chemotactic responses to key growth substrates. These effects could be correlated to protein-level changes within pgl mutants towards a host of cellular transporters, transducer-like proteins required for substrate recognition, and respiration-associated proteins necessary for growth under low oxygen conditions. These data indicate a multi-factorial role for N-glycosylation in C. jejuni physiology.