TIP 5 (UniProt/Swiss-Prot entry Q9UIF9) is the large subunit of the nucleolar remodeling complex NoRC. NoRC causes the repression of ribosomal gene transcription. It was demonstrated that histone deacetylation is involved in this repression and that TIP5 is associated with the histone deacetylase HDAC1 and mediates the deacetylation of histones in the vicinity of the rDNA promoter. The interaction of TIP5 and HDAC1, which is necessary for transcriptional repression, is established by the C-terminal PHD finger and bromodomain.