Fig. 4. FRAP of 5-integrin shows that it is less mobile in adhesive regions of the cell. Confocal images of 5-GFP expressed in a CHO B2 cell plated on 2 µg ml^–1 fibronectin for 3 hours at 37°C. The first image in the time series (A), the first image after bleaching (B) and the last image (C) in the time series are shown. (D) MEF cells transfected with paxillin-CFP and 5-YFP about 1 hour after plating on 1 µg ml^–1 fibronectin. The lower panel shows where the 5-YFP was bleached both under paxillin and in a more central area of the cell. The paxillin-CFP was not bleached. Normalized FRAP curves showing the recovery of 5-GFP from the highlighted regions in A-C (E) or of 5-YFP (F) from the highlighted regions in D. The plots show the normalized intensity of fluorescence following bleaching of organized (open triangles) or nonorganized 5-integrin (filled circles) in either case. Scale bar, 5 µm.