title: Cell wall protein mannosylation determines Candida albicans cell surface hydrophobicity.
abstract: Cell surface hydrophobicity (CSH) has been shown to be an important factor in the ability of the opportunistic pathogenic yeast Candida albicans to adhere to surfaces. Hydrophobic cells adhere more readily to host tissue, and are more resistant to phagocytic killing, than hydrophilic cells. Consequently, CSH plays an important role in the pathogenicity of C. albicans. Previous work suggested a relationship between CSH and cell wall protein glycosylation. The present work tests the hypothesis that changes in outer chain mannosylation, rather than complete loss of oligosaccharide groups, are sufficient to modulate CSH. These studies compared wild-type cells to a variant that has altered mannosylation and is hydrophobic under conditions in which wild-type cells are hydrophilic. Composition analysis of cell surface digests showed that the glycosylation of wild-type cell surface proteins was much more extensive than that seen in the variant. Antibodies which recognize the acid-labile and acid-stable portions of C. albicans mannan showed not only differences between wild-type and variant cells but also differences between wild-type hydrophilic and wild-type hydrophobic cells. The results suggest that exposure of surface hydrophobic regions on C. albicans may be related to the abundance of phosphodiester-linked, acid-labile mannosyl groups rather than the complete loss of outer chain mannosylation on cell wall proteins.
authors.affiliation: Department of Pathology, University of Virginia Medical Center Box 214, Charlottesville, VA 22908, USA.
authors.forename: James
authors.initials: J
authors.lastname: Masuoka
authors.affiliation: Department of Pathology, University of Virginia Medical Center Box 214, Charlottesville, VA 22908, USA.
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Hazen
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002176:Candida albicans / Q000378:metabolism* / Q000472:pathogenicity / Q000648:ultrastructure; D002240:Carbohydrate Sequence; D002473:Cell Wall / Q000378:metabolism* / Q000648:ultrastructure; D005614:Freeze Fracturing; D006031:Glycosylation; D008358:Mannose / Q000032:analysis; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D008562:Membrane Glycoproteins; C025363:mannoproteins; D008358:Mannose