Figure 8.

PI 3-kinase activation in response to FGFR3 derivatives. Immunoprecipitated tyrosine-phosphorylated proteins were subjected to an in vitro lipid kinase assay using PI and [³²P]-γ-ATP as substrates. The control was Vps34p-purified PI 3-kinase from yeast. Arrows indicate the position of the origin and the ³²P-labeled PIP product detected by autoradiography after TLC. Fold increase in PIP production over mock-transfected cells was quantitated using NIH Image and is indicated in the bar graph.