Figure 10.

Ligand-stimulated FGFR3 activation. CHO-K1 cells, lacking endogenous FGFRs, were transfected with full-length FGFR3 derivatives, with or without the Y724F mutation. Top panel, examination of the lysates with anti-phosphotyrosine sera 4G10 shows that stimulation for 30 min with aFGF (200 ng/ml) plus heparin (20 μg/ml) leads to autophosphorylation of WT FGFR3, but not when the Y724F mutation is present. Bottom panel, equal amounts of each receptor were expressed in the samples. In the top panel, lanes 1–3 are from a 20 s ECL exposure of the immunoblot. In contrast, lane 4 is from a 5 s ECL exposure, because the full-length TDII sample appeared overexposed on the 20 s ECL.