Importance of the proximal region of the RIP140 promoter.

<p>(<b>A</b>) Schematic representation of the RIP140 promoter sequence (RIP900 plasmid) showing the E2Fs binding sites (a, b, c, d and e, indicated with grey ovals), the Sp1 binding sites (open circles) and the different 5′ deletion mutants (ΔPAc, ΔPPc and ΔPSc). (<b>B</b>) MCF-7 cells were transiently transfected with the human RIP140 promoter reporter plasmids (25 ng) containing mutations of the E2Fs binding sites together with expression vectors for E2F1 and DP1 (25 ng each). In the left panel, each mutant has one E2F site mutated (mE2Fa, b, c, d and e) or multiple mutations which abolish all sites (E2Fnull). In the right panel, only the indicated site remains intact (E2Fa, b, c, d and e). (<b>C</b> and <b>D</b>) The same experiments as above were repeated with deletion mutants (respectively ΔPAc, ΔPPc, ΔPSc) of the RIP140 promoter (<b>C</b>) or with the proximal promoter region (mutant ΔPSc) with point mutations of the E2F binding sites (mE2Fd and e) (<b>D</b>). All results were expressed as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035839#pone-0035839-g002" target="_blank">Figure 2D</a> and representative experiments are shown (n = 3).