ER beta gene consists of 8 encoding exons. The open reading frame of the coding region is 1,593 bp.

ER beta is mainly expressed in tissues such as the ovary (granulosa cells), prostate (epithelium), testis, epididymis, colon, lung, bladder, bone marrow, salivary gland, vascular endothelium and regions of the brain, including hypothalamus and cortex.

Nucleus

Cellular signaling of estrogen is mediated through two estrogen receptors (ERs), ER alpha and ER beta. The first ER, now known as ER alpha, was cloned in 1986. This receptor was regarded as the only ER that mediates estrogenic effects, until a second ER, now known as ER beta, was cloned from rat prostate. ER alpha and ER beta belong to the superfamily of nuclear receptors and specifically to the family of steroid receptors that act as ligand-regulated transcription factors. ER alpha and ER beta have a high sequence homology and share affinity for the same ligands and DNA response elements.
Binding of ligand activates ERs, by a mechanism that involves dissociation of heat shock proteins and dimerization of receptor proteins. Estrogen-modulated gene transcription is exerted via different mechanisms: the genomic and the nongenomic pathways. The canonical model for ER-mediated regulation of gene expression involves the direct binding of dimeric ER to DNA sequences known as estrogen response elements (EREs), followed by recruitment of a variety of coregulators to alter chromatin structure and facilitate recruitment of the RNA polymerase II (Pol II) transcriptional machinery.
The transcriptional activity of ERs can be modulated by different types of post-translational modifications such as phosphorylation, acetylation, sumoylation, ubiquitination and methylation.
ER alpha and ER beta exhibit different affinities for some natural compounds, and distinct expression patterns in a variety of tissues. Transcriptional activation by ER alpha is mediated by two distinct activation functions: the constitutively active AF-1 and the ligand-dependent AF-2. ER beta seems to have a weaker corresponding AF-1 function and thus depends more on the AF-2 for its transcriptional activation function. ER alpha and ER beta have different activities in certain ligand, cell-type, and promoter contexts.

Chimpanzee (Pan troglodytes), dog (Canis lupus familiaris), cow (Bos taurus), mouse (Mus musculus), rat (Rattus norvegicus) chicken (Gallus gallus), zebrafish (Danio rerio).