Olfactory receptor family 51 subfamily E member 2 (OR51E2)

Olfactory receptor family 51 subfamily E member 2 (OR51E2) is a G protein-coupled receptor originally identified as an olfactory receptor but is also highly expressed in non-olfactory tissues, most notably the prostate, where it is referred to as the prostate-specific G-protein coupled receptor (PSGR)[1][3][6]. OR51E2 is activated by several odorant molecules, particularly short-chain fatty acids such as propionate and acetate, as well as by β-ionone and certain steroid derivatives[1][5][6]. Upon activation, it mediates intracellular signaling, including increased calcium and cAMP, triggering cascades that impact cell proliferation, differentiation, apoptosis, and hormone signaling[3][6]. In cancer biology, particularly prostate cancer, OR51E2 plays a multifaceted role, acting as a potential biomarker for diagnosis and prognosis and contributing to tumor biology by affecting proliferation and cellular differentiation[3]. Its structure has recently been elucidated, providing new insights into ligand recognition and signaling mechanisms[5]. OR51E2 also participates in the regulation of melanocyte and melanoma cell biology and may have functions in other tissues, including the airway and blood pressure regulation[3][6].

Other names

Prostate-specific G-protein coupled receptor (PSGR)HPRAJOlfactory receptor OR11-16OR51E3POR52A2Olfactory receptor 51E2PSGR

Ligand binding activates G protein-coupled signaling, leading to increased intracellular Ca²⁺ and cAMP. Downstream activation of protein kinases (PKA, MAPK3/MAPK1). Modulation of cell proliferation, differentiation, and apoptosis. In prostate cancer, activation can lead to reduced proliferation, cell cycle arrest, and neuroendocrine differentiation. In melanocytes and melanoma, activation induces apoptosis, promotes melanogenesis, and reduces cell migration.