FIGURE 2.

Paxillin functions upstream of Raf/MEK but downstream of the EGFR. A, non-targeting (Nsp) or paxillin (Pax)-specific siRNA-treated LnCAP cells were serum-starved and then stimulated with DHT (25 nm) for the indicated times. Western blots were performed for phosphorylated and total MEK1/2. Cell lysates were from the same experiments represented in Fig. 1C. B and C, paxillin- or non-targeting siRNA-treated LnCAP cells were co-transfected with cDNAs encoding caMEK or caRaf for 72 h. Serum-starved cells were then treated with 25 nm DHT for 30 min. Western blots detected total and phosphorylated Erk1/2 as well as paxillin. D, paxillin or non-targeting siRNA-treated LnCAP cells were stimulated with DHT (25 nm) or EGF (20 ng/ml) for 30 min and phosphorylated, and total EGFR was detected by Western blot. Cell lysates were from the same experiment in Figs. 1, C and D. Each experiment was performed at least three times with similar results.