Figure 6.

Effects of serine phosphorylation on FAK peptide binding to the Cas SH3 domain when Cas binding is restricted to site I of His-FRNK. (A) Representative Western blot of peptide competition assays by using GST-Cas SH3 and His-FRNK P_IIA. As in Figure 5, components were incubated in the presence of increasing amounts (1, 10, 25, 50, or 100 μM) of each peptide and FRNK was detected by immunoblotting with the mAb 2A7 and ¹²⁵I anti-mouse IgG. (B) Quantitation and graphical representation of PhosphorImager data by using His-FRNK P_IIA with 25 or 100 μM peptide competitor. Data are presented using the same methods detailed in Figure 5.