Figure 3.

Differential ER structure and coactivator recruitment by ER agonists, antagonists, and SERMs. Upon binding ER ligands such as estradiol or SERMs, the receptor undergoes a conformational change, allowing the ER to exist in a spectrum of conformations from active to inactive depending on the nature of the bound ligand. This conformation, in turn, regulates the recruitment of specific transcriptional coregulatory proteins and the resulting transcriptional apparatus. Coactivators such as SRC1 bind to the active (agonist-bound) form of the receptor and activate transcription, while corepressors interact with the antagonist-bound receptor, inhibiting transcription. Depending on the cellular and promoter context, both unique and overlapping sets of genes may be regulated by various ligands. Adapted with permission from The American Journal of Cardiology (S35).