Polycomb group RING finger protein 3 (PCGF3)

Component of a Polycomb group (PcG) multiprotein PRC1- like complex, a complex class necessary to maintain the transcriptionally repressive state of many genes, such as Hox genes, throughout evolution. PcG PRC1 complex acts through chromatin remodeling and modification of histones; it mediates monoubiquitination of histone H2A'Lys-119', rendering chromatin heritably changed in its expressibility.

Within the PRC1-like complex, regulates RNF2 ubiquitin ligase activity (PubMed:26151332). Plays a redundant role with PCGF5 as part of a PRC1-like complex that mediates monoubiquitination of histone H2A'Lys-119' on the X chromosome and is required for normal silencing of a single copy of the X chromosome in XX females (By similarity).