Lightning Oral Talk 25th Annual Lorne Proteomics Symposium 2020

Identification of novel N-glycosylation sites from the bacterium Campylobacter jejuni (#21)

Joel Cain 1 2 , Stuart Cordwell 1 2 3 4
  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. Sydney Mass Spectrometry, University of Sydney, Sydney, NSW, Australia

Campylobacter jejuni is the predominant cause of acute gastroenteritis in the developed world. It's ability to perform N-glycosylation is a key trait which contributes  to its pathogenicity as well as establishing a commensal relationship within avian guts (the primary vector for infection). Recently we established that loss of N-glycosylation was associated with an array of phenotypes including aberrant chemotactic responses, altered respiratory preferences, changes in cell morphology and increased susceptibility towards temperature and osmotic stress. Given the lack of concrete connections between known targets of this PTM and the affected phenotypic traits, we looked to broaden the list of known N-glycoproteins within C. jejuni with the aim of identifying putative causative agents. Of the known 131 modification sites, we were able to unequivocally demonstrate occupation of ~80% of known N-glycopeptides in C. jejuni. We were also able to identify 54 novel modification sites, including 15 novel N-glycoproteins. We also looked to assess biological occupancy of novel and previously identified sites from relative quantitation of N-sequon containing peptides between wild-type and an N-glycosylation incompetent C. jejuni strain - an oligosaccharyltransferase mutant, ΔpglB.