Serotonin G Protein-Coupled Receptor-Based Biosensing Modalities in Yeast

Area of Science:

• Biochemistry
• Molecular Biology
• Biotechnology

Background:

• Serotonin is a crucial neurotransmitter regulating physiological functions and is a precursor for therapeutic compounds.
• Human serotonin signaling involves 12 G protein-coupled receptors (GPCRs) interacting with Gα proteins.
• Yeast engineered with human serotonin GPCRs can act as whole-cell biosensors, but systematic characterization is lacking.

Purpose of the Study:

• To systematically assess serotonin biosensing capabilities across a library of human serotonin GPCRs and Gα proteins in yeast.
• To develop high-resolution serotonin quantification methods using engineered yeast biosensors.
• To investigate the functional impact of human serotonin GPCR polymorphisms on signaling.

Main Methods:

• A library of 144 combinations of 12 human serotonin GPCRs and 12 Gα proteins was screened in yeast for reporter gene expression at two pH levels.
• Optimal biosensing designs and pH conditions were identified for high-resolution serotonin sensing.
• Yeast platform used to characterize 19 common serotonin GPCR polymorphisms, with selected variants further tested in mammalian cells.

Main Results:

• Observed a dynamic range of biosensor sensitivities exceeding 4 orders of magnitude across different GPCR-Gα combinations.
• Achieved high-resolution, HPLC-validated sensing of yeast-produced serotonin.
• Identified significant signaling differences among 19 serotonin GPCR polymorphisms in yeast, with some variations showing conserved or divergent behavior in mammalian cells.

Conclusions:

• Demonstrated the potential of engineered yeast systems for comprehensive serotonin biosensing and quantification.
• Highlighted the utility of this platform for characterizing GPCR polymorphisms relevant to human health.
• The study provides insights into serotonin biosensing modalities applicable to biotechnology and human health.