Fig. 4. EPEC attachment induces a clustering of raft components. HeLa cells ectopically expressing annexin 2-GFP (A,C,E) or GPI-GFP (B,D,F) were infected with EPECtir (SE896) and then processed for analysis of the fluorescent protein distribution (A,B) or membrane cholesterol distribution by filipin staining (C,D). Phase contrast images revealing the adherent bacteria are given in E and F, respectively. The enlarged insets show a 2.5-fold magnification of the boxed region. Note that both GPI-anchored GFP, as well as annexin 2-GFP, accumulate together with membrane cholesterol at sites of EPEC attachment. Panels G and H show controls of uninfected HeLa cells stained with filipin (G) or transfected with the GPI-GFP expression construct and processed for fluorescent protein analysis (H). Bar, 10 µm.
