Cells in 10-cm2 dishes were fixed in 1% formaldehyde for 5 min, and fixation was quenched with addition of glycine to 125 mM for an additional 5 min. Cells were harvested by scraping from plates and were washed twice in 1× PBS before storage at −80°C. ChIP was performed as previously described (Shah et al. 2013) except that extracts were sonicated nine times for 5 min each round (30 sec of sonication with intermediate incubation of 30 sec per round) using a Bioruptor (Diagenode). All ChIPs were performed using 500 µg of extract and 2 µg of antibody per sample. Thirty microliters of Protein G Dynabeads (Invitrogen, 100.02D) was used per ChIP. ChIP DNA was used to make sequencing libraries using NEBNext (New England Biolabs). Libraries were quantified (Kapa Biosystems), and sequencing was performed on either Hi-Seq or NextSeq platforms (50-bp, single-end reads) (Illumina).