Figure 1.

Recombinant Msg protein expressed in Saccharomyces cerevisiae does not localize to the cell wall. A, Schematic diagram of the Pneumocystis jirovecii msg construct that was inserted in pESC-URA vector. The hemagglutinin (HA) tag, histidine (His) tag, and enterokinase site were added between the upstream conserved sequence and variable region of msg. B, Western blot analysis of expressed protein, using peroxidase-conjugated anti-HA antibody. Protein extracts prepared from cells transformed with msg construct (lane 1) showed immunoreactivity to 2 approximately 130-kDa bands (arrow), while extracts from cells transformed with vector alone (lane 2) showed no immunoreactivity. C, Immunofluorescence microscopy analysis of yeast cells expressing Msg using FITC-conjugated anti-HA antibody. The cells expressing Msg showed no fluorescence when viewed under UV light, indicating that Msg is not expressed on the yeast cell wall. Yeast cells can be seen under bright light.