Figure 5.

Effect of PDZ-binding motif mutations on GFP integration into iBox-PAK4cat crystals. A, iBox-PAK4cat constructs utilized in this study. B, fluorescent images of cells co-transfected with GFP-NHERF1 PDZ2 and iBox-PAK4cat constructs, as indicated. A full array of images obtained for the co-transfections can be seen in Fig. S7 and equivalent transmitted light images are shown in Fig. S8. Scale bar bottom right indicates 100 μm. C, substitution mutations of the DTRL PDZ-binding motif are associated with significantly lower levels of fluorescence within iBox-PAK4cat crystals (two-way ANOVA with Sidak's multiple comparisons test, F_{(4, 122)} = 287, p < 0.0001). Each point represents the mean fluorescence intensity of a single image containing multiple crystals, as shown in Fig. S9. n = 10–15.