Olfactory receptor (OR) (OR)

Human olfactory receptors (ORs) represent the largest family of G protein-coupled receptors (GPCRs), with approximately 400 functional genes identified in the human genome (UniProt, 2024). While primarily known for their role in the olfactory epithelium where they detect volatile odorants to mediate the sense of smell, these receptors are also ectopically expressed in a wide variety of non-olfactory tissues including the skin, prostate, gut, and heart (Massberg & Hatt, 2018). In these peripheral tissues, ORs function as chemosensors that regulate physiological processes such as sperm chemotaxis, skin wound healing, and serotonin release in the gut (PubMed, 2023). Dysregulation of OR expression has been increasingly linked to various pathologies, particularly in oncology, where specific receptors like OR51E2 are overexpressed in prostate and breast cancers, promoting tumor progression (Rodriguez-Maria et al., 2023). Consequently, ORs are emerging as novel therapeutic targets and diagnostic biomarkers, though achieving drug selectivity remains a challenge due to the high structural similarity across the receptor family (NIH, 2023). Research into synthetic ligands, such as the sandalwood odorant Sandalore, has demonstrated clinical potential in stimulating hair growth and skin regeneration by targeting specific ORs (PubMed, 2019).

Other names

Odorant receptorOlfactory receptor familyORs

Agonism or antagonism of G protein-coupled receptors, typically coupled to the G-alpha-olf protein, which activates adenylyl cyclase to increase intracellular cAMP levels and open cyclic nucleotide-gated ion channels (UniProt, 2024; NIH, 2023).