Increases ligand-dependent transcriptional activity of AR and other nuclear hormone receptors. Interacts with AR, SMARCA4/BRG1 and SMARCE1/BAF57. Interaction with either SMARCA4 and SMARCE1 enhances AR-mediated transcription. Detected at replication foci throughout S phase. Expressed most abundantly in testis with lower levels in heart, brain, pancreas, prostate and ovary. The C-terminal proline-rich domain possesses a significant intrinsic transcriptional activity. This activity is inhibited by the N-terminus in the full-length protein.