Characterisation of CwpA, a putative glycosylphosphatidylinositol-anchored cell wall mannoprotein in the filamentous fungus Aspergillus niger.
Glycosylphosphatidylinositol (GPI)-anchored proteins in fungi are found at the cell surface, either as plasma membrane proteins (GPI-PMPs) or attached by a remnant of the GPI-anchor to the cell wall (GPI-CWPs). GPI-CWPs can be extracted from the cell wall by treatment with hydrofluoric acid (HF), which cleaves the phosphodiester bond that is present in the remnant of the GPI-anchor. The filamentous fungus Aspergillus niger contains at least seven HF-extractable cell wall mannoproteins. One gene encoding an HF-extractable cell wall mannoprotein, cwpA, was cloned and further characterised. The protein sequence of CwpA indicated the presence of two hydrophobic signal sequences both at the N-terminus and C-terminus of the protein, for entering the ER and the addition of a GPI-anchor, respectively. A CwpA-specific antiserum was raised and in combination with fractionation experiments, we show that this protein was abundantly present as an HF-extractable protein in the cell wall of A. niger.
Damveld
Robbert A
RA
Institute of Biology, Clusius Laboratory, Leiden University, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands.
Arentshorst
Mark
M
VanKuyk
Patricia A
PA
Klis
Frans M
FM
van den Hondel
Cees A M J J
CA
Ram
Arthur F J
AF
D000595:Amino Acid Sequence; D001234:Aspergillus niger / Q000737:chemistry* / Q000235:genetics*; D001483:Base Sequence; D002473:Cell Wall / Q000737:chemistry*; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D017353:Gene Deletion; D017261:Glycosylphosphatidylinositols; D006858:Hydrofluoric Acid; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010802:Phylogeny; D021382:Protein Sorting Signals / Q000235:genetics; D017422:Sequence Analysis, DNA
D004271:DNA, Fungal; D005656:Fungal Proteins; D017261:Glycosylphosphatidylinositols; D008562:Membrane Glycoproteins; D021382:Protein Sorting Signals; C025363:mannoproteins; D006858:Hydrofluoric Acid