Figure 4. Vav3 PH domain alone is not sufficient to enhance AR transcriptional activity but interferes with coactivation of AR by wild type Vav3.

A. PC3 cells transfected with AR, PSA-luc and the indicated plasmids encoding: Vav3 (or EV), GFP fused to the Vav3 PH domain (GFP-Vav3 PH) or GFP, Vav3 plus GFP-Vav3 PH or Vav3 plus GFP were treated with vehicle or R1881 (5 nM). Samples were assayed for luciferase activity and normalized to protein concentration. RLU relative to EV with vehicle treatment from 3 independent experiments performed in triplicate are averaged and plotted (RLU/protein ± SEM). Significance was determined by two-tailed Student’s t test (*p<0.05). B. Parallel cultures transfected with the indicated plasmids were subjected to western blot analysis to assess relative expression levels of Vav3, GFP-Vav3 PH and GFP. C. LNCaP cells transfected with GFP-Vav3 PH domain, GFP-Akt PH domain or GFP control vector were fixed and imaged by confocal microscopy. Representative cells from two independent experiments are shown. Lower images are merged with DAPI staining in blue.