Experimental evidence for the interaction of PAK1 with EEA1. Confocal analysis of the cross section (a) and the vertical section (c) of PDGF-induced MEF cell reveals that endogenous EEA1 colocalized (yellow) with PAK1-GFP. (b) Quantification of the colocalization where the x-axis represents the white line in the inset (rotated -90° compared to (a)) and the y-axis represents the fluorescence intensity. The first peak of intensity in both channels indicates that PAK1 (green) and EEA1 (red) were enriched at the same site. (d) Sequence matching (computed with the multiple sequence alignment program ClustalW) obtained for the phage-display selected peptide QLRSEGPF and the aminoacidic sequence of EEA1. (e) Binding of the selected peptide (QLRSEGPF) to GST-CRIB and the negative control performed with GST alone. Binding of the insertless phage was tested with either GST or GST-CRIB, which showed no differences in affinity. The y-axis represents the absorbance (OD 450 nm). Results are the mean of triplicate experiments.