Acts as a basic transcriptional regulator. Represses basic transcription driven by several virus and cellular promoters. When associated with BRD7, activates transcription of glucocorticoid-responsive promoter in the absence of ligand-stimulation. Also plays a role in mRNA processing and transport. Binds avidly to poly(G) and poly(C) RNA homopolymers in vitro. Interacts with the adenovirus type 5 (Ad5) E1B-55 kDa, BRD7, PRMT2, TP53 and NXF1. Associates with histones and BRD7. The RGG-box domain is methylated. Methylated. Its methylation is enhanced in the late phase of adenoviral infection. May be due to intron retention.