In mouse embryonic stem cells (mESCs), the transcriptional network can be divided into three functionally distinct modules: Polycomb, Core, and Myc, and the Polycomb module represses developmental genes []. This family includes the polycomb repressive complex 2-associated factor EPOP (Elongin BC and Polycomb Repressive Complex 2 (PRC2) Associated Protein, also termed C17orf96, esPRC2p48, E130012A19Rik), a scaffold protein expressed in the inner cell mass of the mouse blastocyst serving as a bridging partner between the PRC2/EED-EZH2 complex and the elongin BC complex, and fine-tuning the transcriptional status of Polycomb group (PcG) target genes in embryonic stem cells. Both EPOP and Elongin BC are required to maintain low levels of expression at PRC2 genomic targets []. EPOP interacts with the H2B deubiquitinase USP7 to modulate transcriptional processes in mESCs similar to MYC [].Another member of the family is the uncharacterized SKI/DACH domain-containing protein 1.
