Fig. 5.
A PI3-K inhibitor inhibits UBF phosphorylation in vivo and in vitro. (A) R+ cells in serum-free medium or stimulated with IGF-I were labeled with [32P]orthophosphate as described in Fig. 1. In one set of cells stimulated with IGF-I, the PI3-K inhibitor LY294002 was added 1 h before stimulation. Autoradiograph of the labeled and immunoprecipitated UBF is shown. The numbers below the lanes are the densitometric ratios in arbitrary units. (B) The experiment was repeated in vitro by using the same conditions as in Fig. 4.