Olfactory receptor. The activity of this receptor is probably mediated by G-proteins wich induce elevation of intracellular Ca(2+), cAMP and activation of phosphorylation of the protein kinases PKA and MAPK3/MAPK1. Activation of OR51E2 may affect melanocyte proliferation, differentiation, and melanogenesis and may increase proliferation and migration of primary retinal pigment epithelial (RPE) cells. Activated by the short chain fatty acids (SCFA), acetate and propionate. In response to SCFA, may positively regulate renin secretion and increase blood pressure (By similarity). May also be activated by steroid hormones and regulate cell proliferation (By similarity). Activated by L-lactate in glomus cells (By similarity). Expressed in brain and liver. Expressed only in some areas of the brain and in the olfactory epithelium. Belongs to the G-protein coupled receptor 1 family.