Genome-wide occupancy of FLAG-MED25 and ETV4 in PC3 cells

Our in vitro binding studies support a model whereby MED25 exhibits multivalent interactions with a subset of related ETS factors, ETV1/4/5. We hypothesize that the interaction would allow for coregulation of genes by ETV1/4/5 and MED25, acting perhaps to link the ETVs to the Mediator complex. To explore this possibility, we compared the genome occupancy for FLAG-tagged MED25 and ETV4 in the prostate cancer cell line PC3, which overexpresses ETV4. We also tested for relevance of MED25 and ETV4 binding to for gene expression in PC3s. We found a high degree of overlap in the FLAG-MED25 and ETV4 ChIPs datasets consistent with our model, and also identified a subset of target genes co-dependent on Med25 and ETV4. Overall design: ChIP-seq in PC3 cells expressing FLAG-MED25 using either anti-FLAG antibody or anti-ETV4 antibody.