Fig. 3. The C-terminal portion of SWAP-70 colocalizes with F-actin. (A) The structure of SWAP-70 and its truncation mutants; all constructs were tagged with GFP at the N-terminus. PH, pleckstrin-homology domain. (B) COS7 cells expressing GFP–SWAP-70(448-585), GFP–SWAP-70(448-564), or GFP–SWAP-70 PH were fixed and stained with Phalloidin to visualize F-actin (red), followed by analysis with confocal microscopy. The merged image of SWAP-70 and F-actin is also shown (`merge'). Areas boxed in the panels of GFP–SWAP-70(448-585) are shown at higher magnification in left upper panels. Bar, 20 µm. (C) COS7 cells expressing GFP–SWAP-70 were treated with or without EGF for 5 minutes and fixed with Phalloidin to visualize F-actin (red), followed by analysis with a confocal microscopy. The x/z planes shown in the upper panel are the vertical sections along the white lines shown in the middle part of the panels. Stacked images of each planes of focus (marked as `stacked') and dorsal planes of focus (marked as `dorsal') are shown. Membrane ruffles can be observed clearly in the x/z plane or the dorsal plane (arrowheads). Bar, 20 µm.