Development of a yeast-based sensor platform for evaluation of ligands recognized by the human free fatty acid 2 receptor.

Yeast-based sensors have shown great applicability for deorphanization of G protein-coupled receptors (GPCRs) and screening of ligands targeting these. A GPCR of great interest is free fatty acid 2 receptor (FFA2R), for which short-chain fatty acids such as propionate and acetate are agonists. FFA2R regulates a wide array of downstream receptor signaling pathways in both adipose tissue and immune cells and has been recognized as a promising therapeutic target, having been implicated in several metabolic and inflammatory diseases. While research aiming to identify ligands recognized by FFA2R for translational applications is ongoing, screening is complicated by the complex regulatory and cell-specific responses mediated by the receptor. To simplify screening towards identification of novel ligands, heterologous platforms are valuable tools that offer efficient identification of ligand activity in the absence of regulatory mechanisms. Here, we present a yeast-based sensor designed to evaluate G protein α i1-mediated FFA2R signaling, with an assay time of 3 h. We verify this platform towards the natural agonists, propionate and acetate, and show applicability towards evaluation of synthetic agonists, antagonists, and allosteric agonists. As such, we believe that the developed yeast strain constitutes a promising screening platform for effective evaluation of ligands acting on FFA2R.