Fig. 8. Reduction of PYK2 focal adhesion targeting by FAK. (a) First, fak^-/- fibroblasts were transiently transfected with the empty vector (A-C) or vectors encoding FAK (D-F) or FRNK (G-I). They were then stained with polyclonal antibodies against PYK2 (UBI) (A,D,G) or monoclonal antibodies against paxillin (B) or FAK (E,H); C, F and I are overlay pictures. Arrows indicate the FAK- or FRNK-expressing cells. Bar, 50 µm. (b) Summary of results from (a). More than 100 transfected cells were examined for endogenous PYK2 subcellular localization. Although most fak^-/- cells (>90%) exhibited PYK2 focal adhesion targeting (+++), most fak^-/- cells expressing FAK or FRNK (>80%) showed reduced staining intensity (+) compared with fak^-/- cells without FAK or FRNK expression in the same image field.