Current human free fatty acid receptor nomenclature and key features
| Receptor Name | Human Free Fatty Acid Receptors | ||
|---|---|---|---|
| FFA1 | FFA2 | FFA3 | |
| Previous names | GPR40, FFAR1 | GPR43, FFAR2 | GPR41, FFAR3 |
| Gene location | 19q13.1 | 19q13.1 | 19q13.1 |
| Amino acid length | 300 | 330 | 346 |
| % amino acid identity | 33% to FFA2 | 33% to FFA1 | 34% to FFA1 |
| 34% to FFA3 | 43% to FFA3 | 43% to FFA2 | |
| Activating fatty acid (carbon chain length) | C6–C22, saturated and unsaturated | C1–C6 | C1–C6 |
| Synthetic agonists (commercially available) | Rosiglitazone; troglitazone; GW9508X | ||
| G protein coupling | Gαq/11 and Gαi/o | Gαi/o and Gαq/11 | Gαi/o |
| Human tissue distribution | Highest expression in pancreatic islets, also in gastrointestinal tract, brain, and monocytes | Immune cells including peripheral blood leukocytes, neutrophils, eosinophils; adipocytes; distal ileum; colon | Adipose tissue; spleen; lymph node; bone marrow; peripheral blood mononuclear cells |
| Tissue function | Potentiation of GSIS in pancreatic islets; increase in glucagon secretion | Stimulation of adipogenesis; inhibition of lipolysis; activation of polymorphonuclear cells | Increase in leptin production |
| Disease | Type 2 diabetes | ||
| Knockout animal | Yes | Yes | No |
| Phenotype of knockout | Reduction in capacity of FFAs to augment GSIS | Loss of acetate-mediated reduction in plasma FFA levels | |