Estrogen Related Receptor Gamma (ERRg)

ERRg is a member of nuclear hormone receptor family of steroid hormone receptors. No physiological activating ligand is known for this orphan receptor, but 4-hydroxytamoxifen and diethylstilbestrol act as inverse agonists and deactivate ESRRG. It also seems to be the target of bisphenol A.

There is evidence that bisphenol A functions as an endocrine disruptor by binding strongly to ERR-γ. BPA seems to binds strongly to ERR-γ (dissociation constant = 5.5 nM), but not to the estrogen receptor (ER). BPA binding to ERR-γ preserves its basal constitutive activity. It can also protect it from deactivation from the selective estrogen receptor modulator 4-hydroxytamoxifen.