Fig. 4.

TCF ChIPs at the Egr1 promoter region in Med23 KO ES and MEF cells. ChIP for TCF factors at the SRE clusters in the Egr1 promoter was done in steady-state serum conditions in replicate (n = 4) with KO ES and MEF cells. ES cell (white bars) and MEF (black bars) ChIP was done with anti-TCF, anti-SRF, or preimmune IgG for background control. Precipitated DNA was analyzed by qRT-PCR with primers for each SRE cluster and normalized as the percent of signal relative to input chromatin. Error bars indicate SD from four determinations. The fold difference between ES and MEF cells appear below each ChIP condition. Note that TCFs and SRF ChIP are plotted on different scales. This TCF ChIP was also done with WT cells and showed the same trends in factor binding (fig. S5).