Acts as a transcriptional coactivator. Increases ligand-dependent transcriptional activity of AR and promotes AR sumoylation. The stimulation of AR activity is dependent upon sumoylation (PubMed:14609956, PubMed:26522984). Also functions as a transcriptional coactivator in the TGF-beta signaling pathway by increasing the activity of the SMAD3/SMAD4 transcriptional complex (PubMed:16777850). Involved in transcriptional activation of a subset of NOTCH1 target genes including MYC. Involved in thymocyte and T cell development (By similarity). Involved in the regulation of postmitotic positioning of pyramidal neurons in the developing cerebral cortex (PubMed:30639322).
