Haithem Barbour

Abstract Histone posttranslational modifications are key regulators of chromatin-associated processes including gene expression, DNA replication and DNA repair. Monoubiquitinated histone H2A, H2Aub (K118 in Drosophila or K119 in vertebrates) is catalyzed by the Polycomb group (PcG) repressive complex 1 (PRC1) and reversed by the PcG-repressive deubiquitinase (PR-DUB)/BAP1 complex.

Because the interaction between BAP1 and ASXL2 is important for their stability and tumor suppression33, we sought to investigate the potential role of ubiquitination in coordinating BAP1/ASXL2 stability and function. First, we co-transfected Myc-ASXL2 in HEK293T cells with HA-Ub and Flag-BAP1, and immunoprecipitated (IP) ASXL2 protein to detect its ubiquitination state. Immunoblotting with anti-HA (Ub) revealed a distinct ASXL2 protein band suggesting its monoubiquitination (Fig. 1c).