title: Muc5ac gastric mucin glycosylation is shaped by FUT2 activity and functionally impacts Helicobacter pylori binding.
abstract: The gastrointestinal tract is lined by a thick and complex layer of mucus that protects the mucosal epithelium from biochemical and mechanical aggressions. This mucus barrier confers protection against pathogens but also serves as a binding site that supports a sheltered niche of microbial adherence. The carcinogenic bacteria Helicobacter pylori colonize the stomach through binding to host glycans present in the glycocalyx of epithelial cells and extracellular mucus. The secreted MUC5AC mucin is the main component of the gastric mucus layer, and BabA-mediated binding of H. pylori to MUC5AC confers increased risk for overt disease. In this study we unraveled the O-glycosylation profile of Muc5ac from glycoengineered mice models lacking the FUT2 enzyme and therefore mimicking a non-secretor human phenotype. Our results demonstrated that the FUT2 determines the O-glycosylation pattern of Muc5ac, with Fut2 knock-out leading to a marked decrease in α1,2-fucosylated structures and increased expression of the terminal type 1 glycan structure Lewis-a. Importantly, for the first time, we structurally validated the expression of Lewis-a in murine gastric mucosa. Finally, we demonstrated that loss of mucin FUT2-mediated fucosylation impairs gastric mucosal binding of H. pylori BabA adhesin, which is a recognized feature of pathogenicity.
authors.affiliation: i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Júlio Amaral de Carvalho, 45, 4200-135 Porto, Portugal.|Institute of Molecular Pathology and Immunology of University of Porto, Ipatimup, Rua Júlio Amaral de Carvalho, 45, 4200-135 Porto, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Magalhães
authors.affiliation: Structural and Functional Glycobiology Unit, UMR CNRS 8576, University of Lille, 59655 Villeneuve d'Ascq, France.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Rossez
authors.affiliation: Structural and Functional Glycobiology Unit, UMR CNRS 8576, University of Lille, 59655 Villeneuve d'Ascq, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Robbe-Masselot
authors.affiliation: Structural and Functional Glycobiology Unit, UMR CNRS 8576, University of Lille, 59655 Villeneuve d'Ascq, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Maes
authors.affiliation: i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Júlio Amaral de Carvalho, 45, 4200-135 Porto, Portugal.|Institute of Molecular Pathology and Immunology of University of Porto, Ipatimup, Rua Júlio Amaral de Carvalho, 45, 4200-135 Porto, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Gomes
authors.affiliation: Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Shevtsova
authors.affiliation: Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden.
authors.forename: Jeanna
authors.initials: J
authors.lastname: Bugaytsova
authors.affiliation: Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden.
authors.forename: Thomas
authors.initials: T
authors.lastname: Borén
authors.affiliation: i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Júlio Amaral de Carvalho, 45, 4200-135 Porto, Portugal.|Institute of Molecular Pathology and Immunology of University of Porto, Ipatimup, Rua Júlio Amaral de Carvalho, 45, 4200-135 Porto, Portugal.|Medical Faculty, University of Porto, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal.|Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira no 228, 4050-313 Porto, Portugal.
authors.forename: Celso A
authors.initials: CA
authors.lastname: Reis
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism; D000818:Animals; D001422:Bacterial Adhesion; D005647:Fucosyltransferases / Q000235:genetics / Q000378:metabolism*; D005752:Gastric Mucins / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism; D006031:Glycosylation; D016481:Helicobacter Infections / Q000378:metabolism* / Q000382:microbiology; D016480:Helicobacter pylori / Q000378:metabolism* / Q000502:physiology; D006801:Humans; D007983:Lewis Blood Group Antigens / Q000378:metabolism; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D055271:Mucin 5AC / Q000378:metabolism*; D009093:Mucus / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D011485:Protein Binding; D000097631:Galactoside 2-alpha-L-fucosyltransferase
chemical_list: D018829:Adhesins, Bacterial; D005647:Fucosyltransferases; D005752:Gastric Mucins; D007983:Lewis Blood Group Antigens; D055271:Mucin 5AC; D011134:Polysaccharides; D000097631:Galactoside 2-alpha-L-fucosyltransferase; C400429:BabA protein, Helicobacter pylori; C524679:Muc5ac protein, mouse