LampER is activated by E
whereas amphiER is not activated by ER agonists. The pSG5 constructs containing either amphiER (A), human ERα or human ERβ (B), were tested in transfected Cos 7 cells for their ability to activate the co-transfected cognate ERE-luc reporter plasmid after E2 stimulation (10-6M). (C) GAL4-LBD constructs from several chordate ERs were tested in transfectec 293 cells for their ability to activate a (17m)5x-G-luc reporter plasmid in the presence of increasing doses of E2 (10-9M to 10-6M). (D) Mammalian two-hybrid SRC1 recruitment assay. The GAL4-amphiER-LBD chimera was used with the coactivator SRC1 fused to the strong activation domain VP16 to transfect 293 cells in the presence of increasing doses of E2 (10-9M to 10-6M).