Figure 3.

HSF1 binds to both the 5′UTR promoter and the rs2802292 SNP enhancer region at FOXO3 locus only in cells containing the minor G-allele under oxidative stress. (A) Schematic representation of FOXO3 locus revealing the presence of a putative HSF1 consensus motif in the 5′UTR region at genomic positions 108 553 298–108 553 314. (B–E) ChIP experiments (n = 3) performed on HEK-293 cells homozygous for the rs2802292 G-allele (GG), homozygous GG and TT cells originated from human dermal primary fibroblasts and HAP1 FOXO3 SNP rs2802292 (G to T) and HAP1 parental (G) cells cultured in normal conditions and under oxidative stress (1 h H₂O₂, 100 μM) showing HSF1 occupancy of the 5′UTR region and of the genomic rs2802292 SNP region (B) and the involvement of activating epigenetic modifications such as acetylation of lysine 27 (H3K27ac) (C) and monomethylation of lysine 4 of histone H3 (H3K4me1) (D) on the 5′UTR and the rs2802292 region in the presence of the minor G-allele, but not in TT cells. IgGs were used as an immunoprecipitation control (E). Exon 3 region was used as a control. P-values were derived from t-tests: *P ≤ 0.05.