(A) Changes in abundance of histone PTM categories between interphase and mitosis. (B) Changes in individual histone PTM abundance between interphase and mitosis. (C) Changes in abundance of particular BRD4-binding histone PTMs between interphase and mitosis. (D) Quantitative western blots of BRD4, GAPDH, and multiple histone PTMs during interphase, mitosis, or mitosis after 1 h of 250-nM JQ1 treatment. Non-JQ1 conditions were treated with 1 h of 250-nM DMSO. Results were normalized to within-lane background, GAPDH, and the interphase condition. Conditions with error bars represent n = 2 experiments, means ± SEM; other conditions are n = 1. (E) Changes in abundance of particular histone di-PTM combinations between interphase and mitosis. For (A)–(C) and (E), PTM abundance was normalized to peptide abundance.