title: Structures of the glycosylphosphatidylinositol membrane anchors from Aspergillus fumigatus membrane proteins.
abstract: Glycosylphosphatidylinositol (GPI)-anchored proteins have been identified in all eukaryotes. In fungi, structural and biosynthetic studies of GPIs have been restricted to the yeast Saccharomyces cerevisiae. In this article, four GPI-anchored proteins were purified from a membrane preparation of the human filamentous fungal pathogen Aspergillus fumigatus. Using new methodology applied to western blot protein bands, the GPI structures were characterized by ES-MS, fluorescence labeling, HPLC, and specific enzymatic digestions. The phosphatidylinositol moiety of the A. fumigatus GPI membrane anchors was shown to be an inositol-phosphoceramide containing mainly phytosphingosine and monohydroxylated C24:0 fatty acid. In constrast to yeast, only ceramide was found in the GPI anchor structures of A. fumigatus, even for Gel1p, a homolog of Gas1p in S. cerevisiae that contains diacylglycerol. The A. fumigatus GPI glycan moiety is mainly a linear pentomannose structure linked to a glucosamine residue: Manalpha1-3Manalpha1-2Manalpha1-2Manalpha1-6Manalpha1-4GlcN.
authors.affiliation: Unité Des Aspergillus, Institut Pasteur, 25 Rue Du Docteur Roux, 75724 Paris Cedex 15, France. tfontain@pasteur.fr
authors.forename: Thierry
authors.initials: T
authors.lastname: Fontaine
authors.forename: Thierry
authors.initials: T
authors.lastname: Magnin
authors.forename: Angela
authors.initials: A
authors.lastname: Melhert
authors.forename: Douglas
authors.initials: D
authors.lastname: Lamont
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Latge
authors.forename: Michael A J
authors.initials: MA
authors.lastname: Ferguson
mesh_terms: D001232:Aspergillus fumigatus / Q000737:chemistry*; D015153:Blotting, Western; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D005656:Fungal Proteins / Q000737:chemistry*; D017261:Glycosylphosphatidylinositols / Q000737:chemistry*; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry
chemical_list: D005656:Fungal Proteins; D017261:Glycosylphosphatidylinositols; D008565:Membrane Proteins; D010455:Peptides