Niacin Receptor 1 (NIACR1)

GPR109A is a high affinity receptor for nicotinic acid (niacin) and is a member of the nicotinic acid receptor family of G protein-coupled receptors (the other identified member being GPR109B).GPR109A is a G_i / G_o protein-coupled receptor with high affinity for nicotinic acid.

GPR109A is believed to be an important biomolecular target of niacin which is a widely prescribed drug for the treatment of dyslipidemia and to increase HDL cholesterol but whose therapeutic use is limited by flushing. In GPR109A knockout mice, the effects of niacin on both lipids and flushing is eliminated. Furthermore in arrestin beta 1 knockout mice, niacin's effect on flushing is greatly reduced while the lipid modifying effects are maintained.