Cells at indicated time points were cross-linked by 1% formaldehyde, quenched with 0.125 M glycine. The chromatin DNA was extracted and sheared into 200-400 bp, and immuoprecipitated using a EZ-ChIP kit (Millipore, 17-371), and indicated antibodies. Barcoded ChIP-Seq libraries were made from 1 to 10 ng of chromatin immunoprecipitated DNA (ChIP-DNA) using the NuGen Ovation Ultralow V2 kit. 13 cycles were used for PCR amplification of the libraries. Amplified libraries were checked for adapter artifacts by Agilent Bioanalyzer using DNA high sensitivity reagents and chips (Agilent). All libraries were quantified by qPCR using an Illumina Library Quantification kit (KAPA Biosystems). Libraries were pooled in equimolar amounts and run on the HiSeq 2500 sequencer with a single read 50 cycle run (Illumina).