Characterization of a cell-wall acid phosphatase (PhoAp) in Aspergillus fumigatus.
In the filamentous fungus Aspergillus fumigatus, the vast majority of the cell-wall-associated proteins are secreted proteins that are in transit in the cell wall. These proteins can be solubilized by detergents and reducing agents. Incubation of a SDS/beta-mercaptoethanol-treated cell-wall extract with various recombinant enzymes that hydrolyse cell-wall polysaccharides resulted in the release of a unique protein in minute amounts only after incubation of the cell wall in the presence of 1,3-beta-glucanase. Sequence analysis and biochemical studies showed that this glycoprotein, with an apparent molecular mass of 80 kDa, was an acid phosphatase (PhoAp) that was active on both phosphate monoesters and phosphate diesters. PhoAp is a glycosylphosphatidylinositol-anchored protein that was recovered in the culture filtrate and cell-wall fraction of A. fumigatus after cleavage of its anchor. It is also a phosphate-repressible acid phosphatase. The absence of PhoAp from a phosphate-rich medium was not associated with a reduction in fungal growth, indicating that this cell-wall-associated protein does not play a role in the morphogenesis of A. fumigatus.
Bernard
Muriel
M
Unité des Aspergillus, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France1.
Mouyna
Isabelle
I
Unité des Aspergillus, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France1.
Dubreucq
Guy
G
Unité des Aspergillus, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France1.
Debeaupuis
Jean-Paul
JP
Unité des Aspergillus, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France1.
Fontaine
Thierry
T
Unité des Aspergillus, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France1.
Vorgias
Constantinos
C
National and Kapodistrian University of Athens, 15784 Athens, Greece2.
Fuglsang
Claus
C
Novozymes A/S, Krogshoejvej 36, 2880 Bagsvaerd, Denmark3.
Latgé
Jean-Paul
JP
Unité des Aspergillus, Institut Pasteur, 25 rue du Docteur Roux, 75724 Paris Cedex 15, France1.
D000135:Acid Phosphatase / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001232:Aspergillus fumigatus / Q000201:enzymology* / Q000235:genetics; D002473:Cell Wall / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D016681:Genome, Fungal; D043326:Glucan 1,3-beta-Glucosidase; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017386:Sequence Homology, Amino Acid; D001617:beta-Glucosidase / Q000378:metabolism
D000135:Acid Phosphatase; D001617:beta-Glucosidase; D043326:Glucan 1,3-beta-Glucosidase