Free fatty acid receptor 1 (FFAR1)/GPR40 is a G protein-coupled receptor for long-chain fatty acids such as docosahexaenoic acid and eicosapentaenoic acid ω-3 fatty acids. It is involved in the regulation of insulin release from pancreatic β cells and mediates triglyceride-induced secretion of incretins GLP-1 and GIP from intestinal endocrine cells. Cayman’s FFAR1 (GPR40) Reporter Assay Kit consists of a 96-well plate coated with a transfection complex containing DNA constructs for FFAR1, an engineered G protein that directs Gαq activation signals to the Gαs pathway, and a cAMP response element-regulated secreted alkaline phosphatase (SEAP) reporter (FFAR1 reverse transfection strip plate). Cells grown on the transfection complex will express FFAR1 at the cell surface and the recombinant G protein inside the cell. Binding of agonists to FFAR1 initiates a signal transduction cascade resulting in expression of SEAP, which is secreted into the cell culture medium. Aliquots of culture medium are collected 16-24 hours after stimulation and SEAP activity is measured following addition of a luminescence-based alkaline phosphatase substrate provided in the kit. The kit is easy to use and can be readily applied to high-throughput screening for therapeutic compounds regulating activation of FFAR1. A known FFAR1 agonist, GW 9508, is included in the kit for use as a positive control. The kit provides sufficient reagent to measure SEAP activity at three time points using the three included white assay plates.
