Galactofuranose attenuates cellular adhesion of Aspergillus fumigatus.
Galactofuranose (Galf) is a major molecule found in cell wall polysaccharides, secreted glycoproteins, membrane lipophosphoglycans and sphingolipids of Aspergillus fumigatus. The initial step in the Galf synthetic pathway is the re-arrangement of UDP-galactopyranose to UDP-Galf through the action of UDP-galactopyranose mutase. A mutant lacking the AfUGM1 gene encoding the UDP-galactopyranose mutase has been constructed. In the mutant, though there is a moderate reduction in the mycelial growth associated with an increased branching, it remains as pathogenic and as resistant to cell wall inhibitors and phagocytes as the wild-type parental strain. The major phenotype seen is a modification of the cell wall surface that results in an increase in adhesion of the mutants to different inert surfaces (glass and plastic) and epithelial respiratory cells. The adhesive phenotype is due to the unmasking of the mannan consecutive to the removal of galactofuran by the ugm1 mutation. Removal of the mannan layer from the mutant surface by a mannosidase treatment abolishes mycelial adhesion to surfaces.
Lamarre
Claude
C
Unité des Aspergillus, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France.
Beau
Rémi
R
Balloy
Viviane
V
Fontaine
Thierry
T
Wong Sak Hoi
Joanne
J
Guadagnini
Stéphanie
S
Berkova
Nadia
N
Chignard
Michel
M
Beauvais
Anne
A
Latgé
Jean-Paul
JP
D001232:Aspergillus fumigatus / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D002448:Cell Adhesion; D002460:Cell Line; D004847:Epithelial Cells / Q000382:microbiology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005690:Galactose / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000378:metabolism*; D017353:Gene Deletion; D006801:Humans; D019751:Intramolecular Transferases / Q000235:genetics / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D025282:Mycelium / Q000648:ultrastructure; D013172:Spores, Fungal / Q000254:growth & development; D014530:Uridine Diphosphate / Q000031:analogs & derivatives / Q000096:biosynthesis
D005656:Fungal Proteins; C104136:uridine diphosphate galactofuranose; D014530:Uridine Diphosphate; D019751:Intramolecular Transferases; C098051:UDP-galactopyranose mutase; D005690:Galactose