Related Experiment Video
Updated: Jun 6, 2026

Screening for Phytoestrogens using a Cell-based Estrogen Receptor β Reporter Assay
Published on: June 7, 2020
Transcriptional activity of estrogen-related receptor γ (ERRγ) is stimulated by the phytoestrogen equol
Johanna Hirvonen1, Ann-Marie Rajalin, Gerd Wohlfahrt
1Institute of Biomedicine/Physiology, Biomedicum Helsinki, University of Helsinki, Finland.
Abstract:
Estrogen-related receptor γ (ERRγ) is an orphan nuclear receptor lacking identified natural ligands. The synthetic estrogen receptor ligands 4-hydroxytamoxifen and diethylstilbestrol have, however, been shown to bind to and abolish the constitutive transcriptional activity of ERRγ. Certain phytoestrogens were recently reported to act as agonists of the related ERRα. We investigated whether phytoestrogens also modulated the transcriptional activity of ERRγ. We analyzed a selection of phytoestrogens for their potential agonistic or antagonistic activity on ERRγ. In transiently transfected PC-3 and U2-OS cells equol stimulated the transcriptional activity of ERRγ and enhanced its interaction with the coactivator GRIP1. The agonistic effect of equol was abolished by 4-hydroxytamoxifen. Equol induced a conformational change in the ERRγ ligand-binding domain. Based on structural models of the ERRγ ligand-binding domain, we were able to introduce mutations that modulated the agonistic potential of equol. Finally, equol enhanced the growth inhibitory effect of ERRγ on the prostate cancer PC-3 cells. In conclusion, we have demonstrated that the phytoestrogen equol acts as an ERRγ agonist.
More Related Videos
14:13Detecting Estrogenic Ligands in Personal Care Products using a Yeast Estrogen Screen Optimized for the Undergraduate Teaching Laboratory
Published on: January 1, 2018
06:18An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
Related Concept Videos
Transducer Mechanism: Nuclear Receptors
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
Regulation of the Unfolded Protein Response
Internal Receptors
Cell Specific Gene Expression
Types of Receptors: Internal Receptors
Similar to membrane-bound receptors, the binding of a ligand to the intracellular receptor of causes a conformational change in the...
Role of ER in the Secretory Pathway
Components of the secretory pathway
About a third of proteins synthesized in the cell are sorted via the secretory route. They shuffle between different compartments in membrane-bound vesicles until they reach their final destination. The main intracellular compartments involved...