GPI-anchored cell surface protein of white koji mold

Abstract

A candidate of the GPI-anchored cell surface protein (CwpA) was obtained fromAspergillus kawachii. This protein possessed hydrophobic regions in both the N-terminus and C-terminus, a feature indicating the characteristics of a GPI-anchored protein.
CwpA existed in the membrane fraction of the cell, and it was extracted into the detergent phase (Triton X114) when not treated with PI-PLC, but it remained in the aqueous phase when treated with PI-PLC. CwpA, which was deleted from the GPI anchor signal by the insertion of an artificial stop codon just before the C-terminal hydrophobic region, was secreted. These results suggest that CwpA is a GPI-protein.
Fluorescence was observed at the cell surface in the transformant of the GFP-CwpA fusion gene, indicating the fact that CwpA is anchored to the cell membrane via GPI.