LmjPEM1 and LmjPEM2 are integral membrane proteins. (A) Whole cells were subjected to digitonin fractionation followed by Western blot analysis in the presence of antibodies specific to PMM (cytosolic marker), BIP (luminal endoplasmic reticulum marker), GP63 (GPI-anchored integral membrane protein), LmjPEM1, and LmjPEM2 [38,39,40]. (B) Whole cell extracts were incubated in the absence or presence of 1% CHAPS or 0.5 M NaCl followed by ultracentrifugation. The resulting pellets and supernatants were then analyzed by Western blot in the presence of antibodies specific to BIP, GP63, LmjPEM1, and LmjPEM2 [39,40]. (A), (B), Apparent molecular weight are shown on the left. P, pellet; S, supernatant.