RIN directly binds to the promoter regions of target genes as revealed by chromatin immunoprecipitation. (a) Western blot revealed the specificity of the affinity-purified RIN polyclonal antibodies used for chromatin immunoprecipitation (ChIP) assay. Nuclear proteins were isolated from wild-type and rin mutant fruit at the orange ripening stage and hybridized with the RIN polyclonal antibodies. (b) ChIP-qPCR shows the binding of RIN to the promoter regions of five E2 genes. The promoter structures of the target genes are presented. Blue boxes represent CArG box elements and numbers indicate the position of these motifs relative to the translational start site. Green fragments with upper-case letters represent the regions used for ChIP-qPCR. Values are the percentage of DNA fragments that co-immunoprecipitated with anti-RIN antibodies (black bars) or non-specific antibodies (preimmune rabbit IgG; grey bars) relative to the input DNAs. Error bars represent the SD of three independent experiments.