PRT4165

PRT4165 is a potent inhibitor of PRC1 (polycomb-repressive complex 1)-mediated histone H2A ubiquitylation in vivo and in vitro. PRT4165 inhibits the in vitro histone H2A E3 ubiquitin ligase activity of PRC1 components RING1, RNF2, and a BMI1/RNF2 complex. PRT4165 also inhibits DNA double-strand breaks induced ubiquitylation of histone H2AX. In addition, it prevents Bmi1/Ring1A-mediated ubiquitination and drug-induced degradation of topoisomerase 2α (Top2α).