title: Rbt1 protein domains analysis in Candida albicans brings insights into hyphal surface modifications and Rbt1 potential role during adhesion and biofilm formation.
abstract: Cell wall proteins are central to the virulence of Candida albicans. Hwp1, Hwp2 and Rbt1 form a family of hypha-associated cell surface proteins. Hwp1 and Hwp2 have been involved in adhesion and other virulence traits but Rbt1 is still poorly characterized. To assess the role of Rbt1 in the interaction of C. albicans with biotic and abiotic surfaces independently of its morphological state, heterologous expression and promoter swap strategies were applied. The N-terminal domain with features typical of the Flo11 superfamily was found to be essential for adhesiveness to polystyrene through an increase in cell surface hydrophobicity. A 42 amino acid-long domain localized in the central part of the protein was shown to enhance the aggregation function. We demonstrated that a VTTGVVVVT motif within the 42 amino acid domain displayed a high β-aggregation potential and was responsible for cell-to-cell interactions by promoting the aggregation of hyphae. Finally, we showed through constitutive expression that while Rbt1 was directly accessible to antibodies in hyphae, it was not so in yeast. Similar results were obtained for another cell wall protein, namely Iff8, and suggested that modification of the cell wall structure between yeast and hyphae can regulate the extracellular accessibility of cell wall proteins independently of gene regulation.
authors.affiliation: INRA, UMR1319 Micalis, Jouy-en-Josas, France ; AgroParisTech, UMR Micalis, Thiverval Grignon, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Monniot
authors.affiliation: INRA, UMR1319 Micalis, Jouy-en-Josas, France ; AgroParisTech, UMR Micalis, Thiverval Grignon, France.
authors.forename: Anita
authors.initials: A
authors.lastname: Boisramé
authors.affiliation: INRA, UMR1319 Micalis, Jouy-en-Josas, France ; AgroParisTech, UMR Micalis, Thiverval Grignon, France.
authors.forename: Grégory
authors.initials: G
authors.lastname: Da Costa
authors.affiliation: Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France ; INRA, USC2019, Paris, France.
authors.forename: Muriel
authors.initials: M
authors.lastname: Chauvel
authors.affiliation: UMR Agroécologie 1347 Agrosup/INRA/Université de Bourgogne, Laboratoire Microbiologie Environnementale et Risque Sanitaire (M.E.R.S.), Dijon, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Sautour
authors.affiliation: Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France ; INRA, USC2019, Paris, France ; Université Paris Descartes, Sorbonne Paris Cité, Paris, France ; Assistance Publique - Hôpitaux de Paris Unité de Parasitologie-Mycologie, Service de Microbiologie, Hôpital Necker-Enfants-Malades, Paris, France.
authors.forename: Marie-Elisabeth
authors.initials: ME
authors.lastname: Bougnoux
authors.affiliation: INRA, UMR1319 Micalis, Jouy-en-Josas, France ; AgroParisTech, UMR Micalis, Thiverval Grignon, France.
authors.forename: Marie-Noëlle
authors.initials: MN
authors.lastname: Bellon-Fontaine
authors.affiliation: UMR Agroécologie 1347 Agrosup/INRA/Université de Bourgogne, Laboratoire Microbiologie Environnementale et Risque Sanitaire (M.E.R.S.), Dijon, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Dalle
authors.affiliation: Institut Pasteur, Unité Biologie et Pathogénicité Fongiques, Département Génomes et Génétique, Paris, France ; INRA, USC2019, Paris, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: d'Enfert
authors.affiliation: INRA, UMR1319 Micalis, Jouy-en-Josas, France ; AgroParisTech, UMR Micalis, Thiverval Grignon, France.
authors.forename: Mathias L
authors.initials: ML
authors.lastname: Richard
mesh_terms: D000595:Amino Acid Sequence; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D002176:Candida albicans / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D025301:Hyphae / Q000187:drug effects / Q000378:metabolism*; D011137:Polystyrenes / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011995:Recombination, Genetic / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship
chemical_list: D005656:Fungal Proteins; D011137:Polystyrenes