G-protein coupled receptor for medium and long chain saturated and unsaturated fatty acids that plays an important role in glucose homeostasis. Fatty acid binding increases glucose-stimulated insulin secretion, and may also enhance the secretion of glucagon-like peptide 1 (GLP-1). May also play a role in bone homeostasis; receptor signaling activates pathways that inhibit osteoclast differentiation (By similarity). Ligand binding leads to a conformation change that triggers signaling via G-proteins that activate phospholipase C, leading to an increase of the intracellular calcium concentration. Seems to act through a G(q) and G(i)-mediated pathway. Mediates the anti-inflammatory effects of omega-3 polyunsaturated fatty acids (PUFAs) via inhibition of NLRP3 inflammasome activation. The receptor is strongly activated by gamma-linolenic acid, while myristate gives a lower response. It is also activated by phytanic acid and pristanic acid (PubMed:21570468). Is also activated by synthetic agonists, such as TAK-875 (fasiglifam); this compound is a partial agonist and potentiates the activity of the endogenous ligand gamma-linolenic acid (PubMed:24130766). Detected in brain and pancreas. Detected in pancreatic beta cells. Belongs to the G-protein coupled receptor 1 family.