Engineering orthogonal ligand-receptor pairs from "near drugs"

Area of Science:

• Molecular Biology
• Biochemistry
• Drug Discovery

Background:

• Cell-permeable small molecules are essential for studying cellular pathways.
• Nuclear hormone receptors (NHRs) regulate gene transcription.
• Controlling specific NHRs with external molecules is challenging.

Purpose of the Study:

• To engineer orthogonal ligand-receptor pairs using NHRs.
• To demonstrate the utility of mutated NHRs and inactive drug analogs.
• To create novel tools for experimental biology and gene therapy.

Main Methods:

• Structural analysis of retinoid X receptor (RXR) and retinoic acid receptor (RAR) ligand-binding domains.
• Site-directed mutagenesis of RXR to create variant receptors.
• Screening of "near drugs" (inactive drug analogs) for activation of variant receptors.

Main Results:

• Engineered an orthogonal ligand-receptor pair using a mutated RXR variant (Q275C;I310M;F313I).
• The variant receptor was activated by a specific "near drug" inactive on the wild-type receptor.
• Demonstrated that inactive compounds can be repurposed with mutant proteins.

Conclusions:

• NHRs are suitable for creating orthogonal ligand-receptor pairs.
• This approach provides new tools for experimental biology, biotechnology, and gene therapy.
• Inactive compounds from drug discovery can be combined with mutant proteins to control cellular processes.