Transcriptional repressor that binds to the consensus sequence 5'-CGGACGTT-3' and to the RB1 promoter. Transcriptional activator that promotes histone H4 gene transcription at the G1/S phase transition in conjunction with NPAT. Also activates transcription of the ATM and PRKDC genes. Autoregulates its expression by associating with its own promoter (By similarity). Binds MBD2 and a histone deacetylase complex. Interacts with NPAT (By similarity). Associated with discrete nuclear foci. Ubiquitinated. Ubiquitination may lead to proteasome-mediated degradation (By similarity).