title: Caenorhabditis elegans bacterial pathogen resistant bus-4 mutants produce altered mucins.
abstract: Caenorabditis elegans bus-4 glycosyltransferase mutants are resistant to infection by Microbacterium nematophilum, Yersinia pestis and Yersinia pseudotuberculosis and have altered susceptibility to two Leucobacter species Verde1 and Verde2. Our objective in this study was to define the glycosylation changes leading to this phenotype to better understand how these changes lead to pathogen resistance. We performed MALDI-TOF MS, tandem MS and GC/MS experiments to reveal fine structural detail for the bus-4 N- and O-glycan pools. We observed dramatic changes in O-glycans and moderate ones in N-glycan pools compared to the parent strain. Ce core-I glycans, the nematode's mucin glycan equivalent, were doubled in abundance, halved in charge and bore shifts in terminal substitutions. The fucosyl O-glycans, Ce core-II and neutral fucosyl forms, were also increased in abundance as were fucosyl N-glycans. Quantitative expression analysis revealed that two mucins, let-653 and osm-8, were upregulated nearly 40 fold and also revealed was a dramatic increase in GDP-Man 4,6 dehydratease expression. We performed detailed lectin binding studies that showed changes in glycoconjugates in the surface coat, cuticle surface and intestine. The combined changes in cell surface glycoconjugate distribution, increased abundance and altered properties of mucin provide an environment where likely the above pathogens are not exposed to normal glycoconjugate dependent cues leading to barriers to these bacterial infections.
authors.affiliation: Food and Drug Administration, Center for Biologics Evaluation and Research, Bethesda, Maryland, United States of America.
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Parsons
authors.affiliation: Food and Drug Administration, Center for Biologics Evaluation and Research, Bethesda, Maryland, United States of America.
authors.forename: Rahman M
authors.initials: RM
authors.lastname: Mizanur
authors.affiliation: Food and Drug Administration, Center for Biologics Evaluation and Research, Bethesda, Maryland, United States of America.
authors.forename: Ewa
authors.initials: E
authors.lastname: Jankowska
authors.affiliation: Genetics Unit, Department of Biochemistry, University of Oxford, Oxford, United Kingdom.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Hodgkin
authors.affiliation: Genetics Unit, Department of Biochemistry, University of Oxford, Oxford, United Kingdom.
authors.forename: Delia
authors.initials: D
authors.lastname: O Rourke
authors.affiliation: Genetics Unit, Department of Biochemistry, University of Oxford, Oxford, United Kingdom.
authors.forename: Dave
authors.initials: D
authors.lastname: Stroud
authors.affiliation: Food and Drug Administration, Center for Biologics Evaluation and Research, Bethesda, Maryland, United States of America.
authors.forename: Salil
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: Food and Drug Administration, Center for Biologics Evaluation and Research, Bethesda, Maryland, United States of America.
authors.forename: John F
authors.initials: JF
authors.lastname: Cipollo
mesh_terms: D000818:Animals; D001419:Bacteria / Q000472:pathogenicity*; D017173:Caenorhabditis elegans / Q000378:metabolism* / Q000382:microbiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D009077:Mucins / Q000235:genetics / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D029742:Caenorhabditis elegans Proteins; D009077:Mucins; D011134:Polysaccharides