Relative to Fig. 1: AGO1 locates at ERα binding sites, and its binding is enhanced by E2. (A) Analysis of known DNA binding motifs of TFs expressed in MCF-7 cells at AGO1-associated genomic regions in serum-maintained cells. (B) Enrichment of TF binding at AGO1-associated regions in serum-maintained MCF7 cells. (C) Schematic representation of the hormone treatment experiments time line. (D) Table showing the overlap between the number of genomic sites (peaks) bound by ERα and by AGO1, considering each replicate separately and the common peaks. (E) Correlation heat map between AGO1 ChIP-seq samples and replicates based on read counts data on peak sets. (F) MA plot (gene expression ratios [Yang et al., 2002] depicting fold changes in AGO1 binding affinity between untreated and treated samples. (G and H) MCF-7 cells were hormone starved and then treated with vehicle or E2 for 1 h. (G) ERα binding to the enhancers was assessed by ChIP-qPCR. Data are represented as mean ± SD (n = 3). IP, immunoprecipitation. (H) AGO1 binding to the enhancers was assessed by ChIP-qPCR. Data are represented as mean ± SD (n = 3; *, P < 0.05; **, P < 0.01; two-tailed Student’s t test).