The present invention surprisingly shows that the addition of a heterologous viral-GPCR (G protein-coupled receptor) derived sequence at the amino terminal end of GPCRs improves cell surface expression of such receptors in eukaryotic cells. Transfected cells expressing the above heterologous viral GPCRs on their surface are useful for cell based assays to identify test compounds that increases or modulate activity of a GPCR or a ligand of a GPCR for example for drug discovery, development of novel flavors in the food industry or development of sensors based on odor GPCRs. In addition, membrane extracts derived from transfected cells may be used for example for assays of compounds in drug discovery or for development of sensors comprising such membrane extracts for identification and/or quantification of volatile organic compounds.
