Fig. 4. Interaction of PIG-P with other components of GPI-GnT. FLAG-PIG-P was co-expressed in JY5 cells with GST–PIG-A (lane 1), –PIG-H (lane 2), –PIG-C (lane 3), –GPI1 (lane 4) or –ALDH (lane 5), and their associations were analyzed by co-precipitation. The lysates (in 1% digitonin) were precipitated with anti-FLAG beads and immunoprecipitates were analyzed by western blotting against anti-FLAG (top panel) and anti-GST (middle) antibodies. GST-tagged proteins were collected from the supernatant obtained after the immunoprecipitation by glutathione beads and analyzed by western blotting against anti-GST antibody (bottom). An asterisk in the middle panel indicates the heavy chain of mouse anti-FLAG antibody that was recognized by protein G. Positions of molecular size markers are indicated on the left (kDa).