Functional Landscape of PCGF Proteins Reveals Both RING1A/B-Dependent-and RING1A/B-Independent-Specific Activities

• DOI: 10.1016/j.molcel.2019.04.002
• Publication Date: 2019-04-24T14:33:36Z
• Authors: Andrea Scelfo; Daniel Fernández-...; Simone Tamburri; Marika Zanotti; Elisa Lavarone; Monica Soldi; Tiziana Bonaldi; Karin Johanna Fer...; Diego Pasini
• Keywords: Polycomb-group proteins; PRC2; Transcription; Non-histone protein

Polycomb repressive complexes 1 and 2 (PRC1 PRC2) control cell identity by establishing facultative heterochromatin domains at common sets of target genes. PRC1, which deposits H2Aub1 through the E3 ligases RING1A/B, forms six biochemically distinct subcomplexes depending on assembled PCGF protein (PCGF1-PCGF6); however, it is yet unclear whether these have also specific activities. Here we show that PCGF1 PCGF2 largely compensate for each other, while other proteins high levels specificity associates with transcription repression, whereas PCGF3 PCGF6 associate actively transcribed Notably, can assemble be recruited to several active sites independently RING1A/B activity (therefore, PRC1). For chromatin recruitment, complex requires combinatorial activities its MGA-MAX E2F6-DP1 subunits, an interaction USF1 DNA binding factor.