Fig. 4.

Plk1 phosphorylation of CLIP-170 and p150^Glued increases the stability of the AR. A: Expression of CLIP-170-S195E or -S195E/S1318D increases the level of the AR. Total lysates from LNCaP cells stably expressing CLIP-170 constructs (WT, S195A, S195A/S1318A, T286A, S195E, S195E/1318D or T287D) were subjected to IB with antibodies against the AR or β-actin, and quantified. For comparison, the ratio of AR/β-actin of cells expressing WT CLIP-170 was set to 1.0. B: Expression of CLIP-170-S195A/S1318A enhances degradation of the AR. LNCaP cells stably expressing CLIP-170 constructs (WT or S195A/S1318A) were treated with 75 μg/ml of cycloheximide (CHX) for different times (0, 10, 20, 30 minutes), and harvested for IB. C: Expression of CLIP-170-S195A/S1318A prevents DHT-induced AR activation. LNCaP cells stably expressing CLIP-170 constructs were treated with DHT (100 nM), paclitaxel (100 nM) or both drugs (D+T) for 2 hrs and harvested for IB. DHT, dihydrotestosterone. D: Expression of p150^Glued-S179A reduces the protein level of the AR. Total lysates from LNCaP cells stably expressing p150^Glued constructs (WT, S179A or S179D) were analyzed by IB. E, expression of p150^Glued-S179A inhibits DHT-induced AR activation. LNCaP cells stably expressing p150^Glued constructs (WT or S179A) were treated with DHT or PTX as in C and analyzed by IB.