(A) Schematic illustration of the introduced double mutation (E at position 207 to A and G at position 208 to A) in the first zinc finger of the DNA-binding domain of mouse ERα. (B,C) Transfection studies were performed in ER-deficient TSA cells, using either ERE (B) or AP1 (C) reporters. Cells were transfected with WT ERα or the E207A/G208A mutant. Cells were treated with ethanol vehicle, 1 nM E2, or 100 nM ICI 182,780, and luciferase activity was measured. The E207A/G208A mutant was incapable of activating transcription through EREs but retained the full capacity to activate transcription through AP1. (Jakacka et al., 2002)