Estrogen receptor beta: Tissue distribution and the still largely enigmatic physiological function

Abstract

In 1996, the molecular biology of E2 had to be reevaluated: in an effort to identify novel nuclear receptors or unknown isoforms of existing receptors Kuiper and colleague described the expression of a novel subtype of the estrogen receptor (ER) in rat prostate and ovary. Upon this pioneering discovery the already known ER was renamed ER alpha while the newly described ER was termed ER beta. In this review an attempt is made to summarize the current knowledge regarding the expression and function of ER beta in selected reproductive and non-reproductive organs under physiological conditions. The data suggest that ER beta may be considered as a dominant-negative regulator of ERa modulating transcriptional responses to estrogens. The ratio of ER alpha vs. beta. within a cell may determine the cell sensitivity to estrogens and its biological responses to the hormone. Conclusion: It is not the ligand, it is the multiplicity of receptors which determines the plethora of estrogen actions. This article is part of a Special Issue entitled 'Phytoestrogens'. (C) 2013 Elsevier Ltd. All rights reserved.