SCL recruitment in the absence of DNA binding. Anti-HA or control IgG ChIP of GATA-1–activated (A) and GATA-1–repressed (B) genes in G1E-ER4 cells expressing HA-tagged SCL (HA-SCL) or HA-SCL-RER (HA-SCL*), before and after estradiol (E2) treatment for 21 to 24 hours. The data shown are the averages of 2 (Klf1, Gata2 −2.8), 3 (HS3, Hba-a1, −31, Hba-a1 promoter, Lyl1 and Rgs18 promoters), and 4 (HS2, Hbb-b1, Hbb-b1 promoter, Band3, Band3 promoter, Kit −114, Kit +5) independent experiments. Error bars represent SDs. Note that the decrease in HA-SCL occupancy at the Lyl1 gene is less pronounced than that observed with endogenous SCL (Figure 3C). This is likely the result of leakiness with regard to GATA-1-ER activity in this experiment.