Three olfactory receptors were cloned from a mouse olfactory cDNA library: MOR37; MOR828 and MOR452. The genes were sequenced and confirmed to be the olfactory receptor genes. The human homolog of the C. elegans ODR-4 gene was cloned from a human fetal brain library and shows 22% identity and 44% similarity with the C. elegans protein. Additionally, the protein sequence was found to be homologous to proteins found in other species, including rat, mouse, gallus, danio and tetraodon. Expression studies showed the protein is expressed in a number of tissues, including olfactory tissues (41 out of 44 tissues tested). These results suggest that the role of this protein may include trafficking of non-olfactory GPCR's.