Oxoglutarate Receptor 1 (OXGR1)

G protein-coupled receptors (GPCRs, or GPRs) contain 7 transmembrane domains and transduce extracellular signals through heterotrimeric G proteins.GPR80/GPR99, a close relative of GPR91, responds to alpha-ketoglutarate, an intermediate in the citric acid cycle. Alpha-ketoglutarate stimulated inositol phosphate formation in a GPR99-dependent manner. Because GPR99 activation did not affect cAMP levels and both inositol phosphate formation and calcium ion flux were found to be insensitive to pertussis toxin, GPR99 seems to act exclusively through a GQ-mediated pathway. GPR99 is localized to the plasma membrane. GPR99 mRNA was expressed predominantly in the kidney (mainly in distal tubules) with limited expression in other tissues, including the testis and smooth muscle.