title: Fucosylation and protein glycosylation create functional receptors for cholera toxin.
abstract: Cholera toxin (CT) enters and intoxicates host cells after binding cell surface receptors using its B subunit (CTB). The ganglioside (glycolipid) GM1 is thought to be the sole CT receptor; however, the mechanism by which CTB binding to GM1 mediates internalization of CT remains enigmatic. Here we report that CTB binds cell surface glycoproteins. Relative contributions of gangliosides and glycoproteins to CTB binding depend on cell type, and CTB binds primarily to glycoproteins in colonic epithelial cell lines. Using a metabolically incorporated photocrosslinking sugar, we identified one CTB-binding glycoprotein and demonstrated that the glycan portion of the molecule, not the protein, provides the CTB interaction motif. We further show that fucosylated structures promote CTB entry into a colonic epithelial cell line and subsequent host cell intoxication. CTB-binding fucosylated glycoproteins are present in normal human intestinal epithelia and could play a role in cholera.
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States.
authors.forename: Amberlyn M
authors.initials: AM
authors.lastname: Wands
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States.
authors.forename: Akiko
authors.initials: A
authors.lastname: Fujita
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States.
authors.forename: Janet E
authors.initials: JE
authors.lastname: McCombs
authors.affiliation: Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.|Mucosal Immunobiology and Vaccine Center, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Jakob
authors.identifier: http://orcid.org/0000-0002-3840-1008
authors.initials: J
authors.lastname: Cervin
authors.affiliation: Department of Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dedic
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Rodriguez
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States.
authors.forename: Nicole
authors.initials: N
authors.lastname: Nischan
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States.
authors.forename: Michelle R
authors.initials: MR
authors.lastname: Bond
authors.affiliation: Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Marcel
authors.initials: M
authors.lastname: Mettlen
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States.
authors.forename: David C
authors.initials: DC
authors.lastname: Trudgian
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States.
authors.forename: Andrew
authors.initials: A
authors.lastname: Lemoff
authors.affiliation: Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.|Mucosal Immunobiology and Vaccine Center, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Marianne
authors.initials: M
authors.lastname: Quiding-Järbrink
authors.affiliation: Department of Surgery, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Gustavsson
authors.affiliation: Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.|School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Catharina
authors.initials: C
authors.lastname: Steentoft
authors.affiliation: Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.|School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Clausen
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States.
authors.forename: Hamid
authors.initials: H
authors.lastname: Mirzaei
authors.affiliation: Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.|Department of Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Susann
authors.initials: S
authors.lastname: Teneberg
authors.affiliation: Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.|Mucosal Immunobiology and Vaccine Center, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Yrlid
authors.affiliation: Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, United States.
authors.forename: Jennifer J
authors.identifier: http://orcid.org/0000-0001-5373-3329
authors.initials: JJ
authors.lastname: Kohler
mesh_terms: D002460:Cell Line; D002772:Cholera Toxin / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D005677:G(M1) Ganglioside / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D011956:Receptors, Cell Surface / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D005677:G(M1) Ganglioside; D002772:Cholera Toxin
keywords: biochemistry; cholera; endocytosis; epithelial cells; glycolipids/gangliosides; glycoprotein; infectious disease; microbiology; none; toxins