Fig 1: Induction of ER stress increases XBP1s binding to the promoters of downstream target genes.Chromatin immunoprecipitations were performed with cross-linked chromatin from MDA-MB-231 cells treated with Tg (0.5 μM) alone or in combination with MKC8866 (MKC, 20 μM) for 18 h using either XBP1s or control rabbit IgG antibodies. The enriched DNA was quantified by qPCR using primers designed against (A) the promoter of PERK or (B) exon 1 of DNAJB9. The amount of immunoprecipitated DNA in each sample is represented as signal relative to the total amount of input chromatin, which is equivalent to one. Mean percent signal relative to input ± SD, N = 3. Statistical significance for all qPCR experiments was determined using one-way ANOVA followed by TUKEY HSD post-hoc analysis. *p ≤ 0.05, ***p ≤ 0.001.