Direct evidence of host-mediated glycosylation of NleA and its dependence on interaction with the COPII complex

ABSTRACT

Non-LEE-encoded Effector A (NleA) is a type III secreted effector protein of enterohaemorrhagic and enteropathogenic Escherichia coli as well as the related mouse pathogen Citrobacter rodentium. NleA translocation into host cells is essential for virulence. We previously published several lines of evidence indicating that NleA is modified by host-mediated mucin-type O-linked glycosylation, the first example of a bacterial effector protein modified in this way. In this study, we use lectins to provide direct evidence for the modification of NleA by O-linked glycosylation and determine that the interaction of NleA with the COPII complex is necessary for this modification to occur.

KEYWORDS:

• EPEC
• EHEC
• Citrobacter rodentium
• type III secretion
• effectors
• NleA
• post-translational modification
• glycosylation
• O-GalNAc
• Tn antigen
• core 1 O-glycan
• COPII

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

LB and SG conceptualized and designed the experiments. LB performed the experiments and analyzed the data. FLM provided technical support. SG supervised the project. The manuscript was written by LB and edited by FLM and SG.

Data availability statement

The data that support the findings of this study are available from the corresponding author, SG, upon reasonable request.

Additional information

Funding

This work was supported by a National Sciences and Engineering Research Council of Canada (NSERC) Discovery Grants (RGPIN-2014-05119 & RGPIN-2023-04257) awarded to SG. FLM is supported by Canadian Institute for Health and Research (CIHR grant FDN_159902), the Canadian Funds for Innovation – Major Science Initiative – GlycoNET Integrated Services (grant #42481) and McGill Interdisciplinary Initiative in Immunity and Infection. LB is supported by Fonds de Recherche Quebec Santé (FRQS) Training Awards.