title: Glycosylphosphatidylinositols synthesized by Trichophyton rubrum in a cell-free system.
abstract: The opportunistic fungi Trichophyton rubrum and T. mentagrophytes, are responsible for relatively non-inflammatory chronic dermatophytes infections in immunocompromised patients but also in healthy individuals. This chronic infection is associated with immunosuppressive effects of the cell wall components particularly the polysaccharides secreted by these organisms. We have studied glycosylphosphatidylinositol (GPI) anchor biosynthesis in the pathogenic fungus T. rubrum and could demonstrate that T. rubrum is able to synthesize GPI structures. Glycolipids synthesized in a cell-free system prepared from the dermatophyte T. rubrum and labeled with [3H]mannose, and [3H]galactose using GDP-[3H]mannose and UDP-[3H]galactose, respectively, were identified and structurally characterized as GPIs. The evolutionary conserved backbone of T. rubrum GPIs incorporates galactose. Further, all glycolipids lack the acyl group on the inositol which was shown for Saccharomyces cerevisiae and mammalian GPIs. Our data suggest significant differences in the GPI biosynthetic pathway between mammalian and T. rubrum cells that could perhaps be exploited for the development of an antimycotic for Trichophyton infection.
authors.affiliation: Institut für Virology, Medizinisches Zentrum für Hygiene und Medizinische Mikrobiologie, Philipps-Universität Marburg, Robert-Koch-Strasse 17, D-35037 Marburg, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Pusch
authors.forename: Isaak
authors.initials: I
authors.lastname: Effendy
authors.forename: Ralph T
authors.initials: RT
authors.lastname: Schwarz
authors.forename: Nahid
authors.initials: N
authors.lastname: Azzouz
mesh_terms: D000215:Acylation; D002462:Cell Membrane / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D005690:Galactose / Q000378:metabolism; D006017:Glycolipids / Q000096:biosynthesis / Q000737:chemistry; D017261:Glycosylphosphatidylinositols / Q000096:biosynthesis*; D006801:Humans; D007294:Inositol / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D014249:Trichophyton / Q000378:metabolism*; D014316:Tritium / Q000378:metabolism
chemical_list: D006017:Glycolipids; D017261:Glycosylphosphatidylinositols; D011134:Polysaccharides; D014316:Tritium; D007294:Inositol; D005690:Galactose