Multifunctional nucleolar protein that terminates ribosomal gene transcription, mediates replication fork arrest and regulates RNA polymerase I transcription on chromatin. Plays a dual role in rDNA regulation, being involved in both activation and silencing of rDNA transcription. Interaction with BAZ2A/TIP5 recovers DNA-binding activity. Oligomer. The oligomeric structure enables to interact simultaneously with two separate DNA fragments. Interacts with BAZ2A/TIP5. Interacts with CAVIN1. Interacts (via the N-terminal region (NRD) and a C-terminal region) with CDKN2A/ARF; the interaction is direct. Interacts (via C-terminal region) with NPM1/B23. May be localized to the nucleolus in an NPM1/B23-dependent manner. May be displaced from the nucleolus into the nucleoplasm in an CDKN2A/ARF-dependent manner. May shuttle back and forth from nucleoplasm to nucleolus. The N-terminal region (NRD) inhibits DNA-binding via its interaction with the C-terminal region. Contaminating sequence. Potential poly-A sequence. Contaminating sequence. Potential poly-A sequence. Contaminating sequence. Sequence of unknown origin in the N-terminal part. Contaminating sequence. Sequence of unknown origin in the N-terminal part. Contaminating sequence. Sequence of unknown origin in the N-terminal part. Contaminating sequence. Sequence of unknown origin in the N-terminal part. Contaminating sequence. Sequence of unknown origin in the C-terminal part.