Figure 8.

In Cos cells expressing very low amount of hAR, stimulation by 0.001 nM R1881 triggers the Src kinase activity but not gene transcription. Cos cells were transfected with the ARE-3416-Luc reporter gene in the absence or presence of the indicated amounts of hAR cDNA. (A) Cells were left unstimulated or stimulated for 18 h with the indicated concentrations of the androgen R1881. The luciferase activity was assayed, normalized using β-gal as an internal control, and expressed as fold induction. The same lysates were used for Western blot analysis with the C-19 anti-AR Ab (A, inset). (B) Quiescent cells were left unstimulated or stimulated for 2 min with the indicated concentrations of R1881. Lysates were either immunoblotted with the C-19 anti-AR Ab (top) or immunoprecipitated with anti-Src mAb. Immunoprecipitates were either blotted with anti-Src mAb (middle) or assayed for Src kinase activity using enolase as a substrate (bottom).