Abstract
Campylobacter jejuni is the leading cause of bacterial gastroenteritis in the world. A number of factors are believed to contribute to the ability of C. jejuni to cause disease within the human host including the secretion of non-flagellar proteins via the flagellar type III secretion system (FT3SS). Here for the first time we have utilised quantitative proteomics using stable isotope labelling by amino acids in cell culture (SILAC), and label-free liquid chromatography-mass spectrometry (LC/MS), to compare supernatant samples from C. jejuni M1 wild type and flagella-deficient (flgG mutant) strains to identify putative novel proteins secreted via the FT3SS. Genes encoding proteins that were candidates for flagellar secretion, derived from the LC/MS and SILAC datasets, were deleted. Infection of human CACO-2 tissue culture cells using these mutants resulted in the identification of novel genes required for interactions with these cells. This work has shown for the first time that both CJM1_0791 and CJM1_0395 are dependent on the flagellum for their presence in supernatants from C. jejuni stains M1 and 81–176. Biological significanceThis study provides the most complete description of the Campylobac er jejuni secretome to date. SILAC and label-free proteomics comparing mutants with or without flagella have resulted in the identification of two C. jejuni proteins that are dependent on flagella for their export from the bacterial cell.
Highlights
Campylobacter jejuni is the leading cause of foodborne bacterial gastroenteritis in the world [1]
In this study we have used a combination of SILAC and label-free LC-MS to investigate the C. jejuni flagellumdependant secretome
In this study we have used a combination of SILAC and label-free liquid chromatography-mass spectrometry (LC/MS) to screen C. jejuni secretomes obtained from WT M1 and flagellum-deficient strains
Summary
Campylobacter jejuni is the leading cause of foodborne bacterial gastroenteritis in the world [1]. Research investigating C. jejuni pathogenesis has identified important roles for flagellum-dependent motility, adhesion/invasion of host epithelial cells and toxin production among others, as factors important for causing human disease [3]. These factors are frequently observed among bacterial pathogens, C. jejuni appears unlike other enteric pathogens with respect to extracellular protein secretion [4]. It has been proposed that C. jejuni utilises its flagellum for motility and to act as a conduit for the secretion of non-flagellar proteins [5].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
