Probable pheromone receptor. Shows high specificity for 4-hydroxyphenylacetic acid. Activation of the receptor stimulates intracellular calcium release. Highly expressed in the olfactory rosette where it localizes to a subset of olfactory sensory neurons, mainly in the apical region of the neuroepithelium. Not detected in other tissues tested. Belongs to the G-protein coupled receptor 1 family.