Screening for Serotonin Receptor 4 Agonists Using a GPCR-Based Sensor in Yeast

Area of Science:

• Pharmacology
• Biotechnology
• Neuroscience

Background:

• G-protein-coupled receptors (GPCRs) are crucial drug targets, with over 30% of marketed pharmaceuticals acting on them.
• Serotonin receptor 4 (5-HTR4) agonists are clinically relevant for treating constipation-predominant irritable bowel syndrome.
• Identifying novel ligands for GPCRs remains a key challenge in drug discovery.

Purpose of the Study:

• To develop and validate a high-throughput screening (HTS) assay for identifying ligands of the human serotonin receptor 4 (5-HTR4).
• To leverage a yeast cell surface display system for GPCR-based drug discovery.
• To enable rapid screening of chemical libraries for novel 5-HTR4 modulators.

Main Methods:

• A novel screening platform was engineered using yeast to display the human 5-HTR4 on the cell surface.
• Activation of the cell surface-expressed 5-HTR4 was coupled to a luciferase reporter gene expression system.
• The assay's throughput was optimized to screen over one thousand compounds per day, with a rate of one compound per second.

Main Results:

• Successfully established a functional yeast-based screening assay for the human 5-HTR4.
• Demonstrated the feasibility of coupling receptor activation to a quantifiable reporter signal (luciferase).
• Achieved a high-throughput screening capacity suitable for large-scale compound library analysis.

Conclusions:

• The developed yeast-based GPCR screen is a powerful and efficient tool for identifying novel 5-HTR4 ligands.
• This platform accelerates the discovery of potential therapeutics for conditions like irritable bowel syndrome with constipation.
• The methodology is adaptable for screening ligands against other GPCR targets, broadening its applicability in drug discovery.