Scaffold protein that serves as a bridging partner between the PRC2/EZH2 complex and the elongin BC complex: required to fine-tune the transcriptional status of Polycomb group (PcG) target genes in embryonic stem cells (ESCs). Plays a key role in genomic regions that display both active and repressive chromatin properties in pluripotent stem cells by sustaining low level expression at PcG target genes: acts by recruiting the elongin BC complex, thereby restricting excessive activity of the PRC2/EZH2 complex. Interaction with USP7 promotes deubiquitination of H2B at promoter sites. Acts as a regulator of neuronal differentiation.
