Related Experiment Video
Updated: Aug 9, 2026

Rapid Synthesis and Screening of Chemically Activated Transcription Factors with GFP-based Reporters
Published on: November 27, 2013
A modified oestrogen receptor ligand-binding domain as an improved switch for the regulation of heterologous proteins
T D Littlewood1, D C Hancock, P S Danielian
1Molecular Endocrinology Laboratories, Imperial Cancer Research Fund, London, UK.
Abstract:
A number of proteins have been rendered functionally oestrogen-dependent by fusion with the hormone-binding domain of the oestrogen receptor. There are, however, several significant disadvantages with such fusion proteins. First, their use in cells in vitro requires phenol red-free medium and laborious stripping of steroid hormones from serum in order to avoid constitutive activation. Secondly, control of oestrogen receptor fusion proteins in vivo is precluded by high endogenous levels of circulating oestrogens. Thirdly, the hormone-binding domain of the oestrogen receptor functions as a hormone-dependent transcriptional activation domain making interpretation of fusions with transcription factors problematical. In order to overcome these drawbacks we have used a transcriptionally inactive mutant of the murine oestrogen receptor which is unable to bind oestrogen yet retains normal affinity for the synthetic ligand, 4-hydroxytamoxifen. When the hormone-binding domain of this mutant oestrogen receptor is fused to the C-terminus of the c-Myc protein, Myc-induced proliferation and apoptosis in fibroblasts becomes dependent on 4-hydroxytamoxifen, but remains refractory to 17 beta-oestradiol.
More Related Videos
06:21An Ecdysone Receptor-based Singular Gene Switch for Deliberate Expression of Transgene with Robustness, Reversibility, and Negligible Leakiness
Published on: May 7, 2018
09:07Detecting the Ligand-binding Domain Dimerization Activity of Estrogen Receptor Alpha Using the Mammalian Two-Hybrid Assay
Published on: December 19, 2018
Related Concept Videos
Internal Receptors
Ligand Binding and Linkage
Signal Transduction: Overview
Typically, signal transduction involves three...
Transducer Mechanism: Enzyme-Linked Receptors
Major types that are helpful drug targets include:
Transducer Mechanism: Nuclear Receptors
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
The Two-State Receptor Model
The binding affinity of a drug determines its interaction with one...