Cdc73 is necessary for proper recruitment of PAFc and MLL fusion proteins to target loci. ChIP assays were performed on the MA-Cdc73fl-CreER cell line treated with either EtOH (solid black lines) or 100 nM 4-OHT (dotted black lines) for 48 hours. The Meis1 locus (transcribed from left to right) is shown schematically with the sites of primer probe sets recognizing exon 1 and intron 8 of Meis1. IPs performed in EtOH-treated cells are shown in gray, and IPs performed in 4-OHT cells are shown in black. ChIP experiments were performed for (A) Cdc73, (B) Paf1, (C) Flag (MLL-AF9 fusion protein), (D) MllC, (E) H3K4me3, (F) H3K79me2, (G) H2Bub, and (H) RNA Pol II. All binding was calculated as a percentage of 1% input chromatin—except in E, F, and G—that are then divided by total histone H3 and presented in relation to binding at exon 1 in EtOH-treated cells (mean ± SD; n = 2 independent experiments performed in duplicate; *P < .05, **P < .01). Additional ChIP data are presented in supplemental Figure 5. Ig, immunoglobulin.