Polycomb group RING finger protein 1 is a protein that in humans is encoded by the PCGF1 gene.

PCGF1 is a mammalian homolog of the Drosophila polycomb group genes, which act as transcriptional repressors to regulate anterior-posterior patterning in early embryonic development (Nunes et al., 2001 [PubMed 11287196]). See also PCGF2 (MIM 600346).[supplied by OMIM, Aug 2008].
Function: Component of the Polycomb group (PcG) multiprotein BCOR complex, a complex required to maintain the transcriptionally repressive state of some genes, such as BCL6 and the cyclin-dependent kinase inhibitor, CDKN1A. Transcriptional repressor that may be targeted to the DNA by BCL6; this transcription repressor activity may be related to PKC signaling pathway. Represses CDKN1A expression by binding to its promoter, and this repression is dependent on the retinoic acid response element (RARE element). Promotes cell cycle progression and enhances cell proliferation as well. May have a positive role in tumor cell growth by down-regulating CDKN1A.