The reduction of ELK1 level decreases the ability of HNF4α to interact with the promoters of a subset of genes. (A), HepG2 cells were transfected with siControl (siCtr) or siELK1. Protein interaction of HNF4α and ELK1 was determined by ChIP assay with either antibody against HNF4α or goat normal IgG (IgG). Chromatin-immunoprecipitated DNA was analyzed by PCR with primers specific for the ELK1 binding sites in the promoter regions of COL4A1, ZNF175, MMP15 and SEC24A genes. The result shown in (A) is a representative experiment, replicated three times with similar results. (B), Histograms show densitometric analyses of relative binding abilities. Values represent mean ± SD of three separate experiments. The relative quantitative analysis was carried out by comparison of siELK1 with siControl, and the siControl was set at 1. *p < 0.05 and **p < 0.01 indicate a significant difference compared to siCtr. IP, immunoprecipitation.
Wang et al. BMC Genomics 2011 12:128 doi:10.1186/1471-2164-12-128