Figure 4.

Structural composition of estrogen receptor (ER)α and ERβ. Both receptors have four functional domains that harbor a DNA-binding domain (DBD), a ligand-binding domain (LBD) and two transcriptional activation functions (AF-1 and AF-2), as indicated for ERβ. The percent of homology in these domains between ERα and ERβ is indicated, as well as the location of several phosphorylation sites in ERα whereby this receptor is activated by important kinases that modulate a wide variety of cellular events. aa, amino acids; Akt, serine/threonine specific-protein kinase family encoded by the Akt genes; CDK2, cyclin-dependent kinase 2; MAPK, mitogen activated protein kinase; PKA, protein kinase A; Src: steroid receptor coactivator.