Fig. 4: COMMD4 binds to histone H2A-H2B and regulates the monoubiquitination of H2B.
From: COMMD4 functions with the histone H2A-H2B dimer for the timely repair of DNA double-strand breaks
a Immunoblot showing H2B monoubiquitination in control and COMMD4-depleted cells ±5 μg/ml of Actinomycin D and ±irradiation. b Immunofluorescence showing RNF40 protein levels with 6 Gy IR at 0 and 4 h post-IR treatment in control and COMMD4-depleted cells. Scale bar denotes 5 μm. Fifty cells were quantified per condition. c In vitro ubiquitination assay of H2B ± recombinant COMMD4 or with COMMD4 and without the E2 enzyme. Monoubiquitination and polyubiquitination of H2B is shown. d Direct interaction between COMMD4 and H2A/H2B, demonstrating that COMMD4 preferentially binds H2B. e In vitro direct interaction between H2A, H2B and COMMD4 ± recombinant CK2. H2B was used pull-out the complexes and shows loading. f Same as e, however, COMMD4 was used to pull-out the complexes. g Direct interaction between H2A, H2B and COMMD4, in the absence and presence of purified nucleosomes, ±recombinant ATM and CK2. COMMD4 was used pull-out the complexes and shows the loading.
