Acts as a transcriptional repressor. An histone deacetylase (HDAC) activity is required for transcription repression. May play a role in telomere stability. Interacts (via PAH3) with ALY2. Interacts (via PAH2) with TBP1. Interacts with ALY3, GATA21, TRP2, TKI1, VAL1, SKP1B, FBX5 and PUB14. A number of isoforms are produced. According to EST sequences.