Estrogen receptor beta

Estrogen receptor beta (ER-β), also known as NR3A2 (nuclear receptor subfamily 3, group A, member 2), is one of two main types of is_associated_with::estrogen receptor, a is_associated_with::nuclear receptor which is activated by the sex hormone is_associated_with::estrogen. In humans, ER-β is encoded by the ESR2 is_associated_with::gene.

Function
Estrogen receptor β is a member of the family of is_associated_with::estrogen receptors and the superfamily of is_associated_with::nuclear receptor transcription factors. The gene product contains an N-terminal is_associated_with::DNA binding domain and C-terminal ligand binding domain and is localized to the nucleus, cytoplasm, and mitochondria. Upon binding to 17-β-estradiol, estriol or related ligands, the encoded protein forms homo-dimers or hetero-dimers with estrogen receptor α that interact with specific DNA sequences to activate transcription. Some isoforms dominantly inhibit the activity of other estrogen receptor family members. Several alternatively spliced transcript variants of this gene have been described, but the full-length nature of some of these variants has not been fully characterized.

ER-β may have anti-proliferative effects and therefore oppose the actions of ER-α in reproductive tissue. ER-β may also have an important role in adaptive function of the lung during pregnancy.

Estrogen receptor β is a potent tumor suppressor and plays a crucial role in many cancer types such as is_associated_with::prostate cancer.

Tissue distribution
ER-β is expressed by many tissues including the is_associated_with::uterus, blood monocytes and tissue macrophages, colonic and pulmonary epithelial cells and in prostatic epithelium and in malignant counterparts of these tissues. Also, ER-β is found throughout the brain at different concentrations in different neuron clusters.

ER-β abnormalities
ER-β function is related to various cardiovascular targets including ATP-binding cassette transporter A1 (ABCA1) and apolipoprotein A1 (ApoA-1). Polymorphism may affect ER-β function and lead to altered responses in postmenopausal women receiving hormone replacement therapy (HRP).

Interactions
Estrogen receptor beta has been shown to interact with:
 * CCND1,
 * ESR1
 * is_associated_with::MAD2L1,
 * NCOA3,
 * is_associated_with::NCOA6,
 * is_associated_with::RBM39, and
 * SRC.