Structure-Guided Approach to Relieving Transcriptional Repression in Resistance to Thyroid Hormone alpha.
Romartinez-Alonso, B., Agostini, M., Jones, H., McLellan, J., Sood, D.E., Tomkinson, N., Marelli, F., Gentile, I., Visser, W.E., Schoenmakers, E., Fairall, L., Privalsky, M., Moran, C., Persani, L., Chatterjee, K., Schwabe, J.W.R.(2022) Mol Cell Biol 42: e0036321-e0036321
- PubMed: 34871063 
- DOI: https://doi.org/10.1128/MCB.00363-21
- Primary Citation of Related Structures:  
7QDT - PubMed Abstract: 
Mutations in thyroid hormone receptor α (TRα), a ligand-inducible transcription factor, cause resistance to thyroid hormone α (RTHα). This disorder is characterized by tissue-specific hormone refractoriness and hypothyroidism due to the inhibition of target gene expression by mutant TRα-corepressor complexes. Using biophysical approaches, we show that RTHα-associated TRα mutants devoid of ligand-dependent transcription activation function unexpectedly retain the ability to bind thyroid hormone. Visualization of the ligand T3 within the crystal structure of a prototypic TRα mutant validates this notion. This finding prompted the synthesis of different thyroid hormone analogues, identifying a lead compound, ES08, which dissociates corepressor from mutant human TRα more efficaciously than T3. ES08 rescues developmental anomalies in a zebrafish model of RTHα and induces target gene expression in TRα mutation-containing cells from an RTHα patient more effectively than T3. Our observations provide proof of principle for developing synthetic ligands that can relieve transcriptional repression by the mutant TRα-corepressor complex for treatment of RTHα.
Organizational Affiliation: 
Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicestergrid.9918.9, Leicester, United Kingdom.