Retinoblastoma binding protein 4 （RBBP4） is a ubiquitously expressed nuclear protein which is a member of a highly conserved subfamily of WD-repeat proteins. RBBP4 is present in protein complexes involved in histone acetylation and chromatin assembly. In addition， RBBP4 is part of co-repressor complexes， which is a fundamental component of transcriptional silencing. RBBP4 is observed among several cellular proteins which bind directly to a retinoblastoma protein to regulate cell proliferation. RBBP4 also is a part of the Mi-2 complex which is implicated in chromatin remodeling and transcriptional repression connected with histone deacetylation.
