A NEW FAMILY OF ORPHAN G-PROTEIN-COUPLED RECEPTORS PREDOMINANTLY EXPRESSED IN THE BRAIN

The cloning of a cDNA encoding a G protein-coupled receptor homologous to the endothelin type B receptor, but unable to bind endothelin, was recently reported and termed ETBR-LP. We report here the isolation of a human cDNA encoding a receptor that is highly related to ETBR-LP an d which was therefore termed ETBR-LP-2. Comparison of the two amino ac id sequences revealed 68% overall homology and 48% identity. As is the case for ETBR-LP, the new receptor is strongly expressed in the human central nervous system (e.g. in cerebellar Bergmann glia, cerebral co rtex, internal capsule fibers). Membranes of HEK-293 cells stably expr essing ETBR-LP-2 did not bind endothelin-1, endothelin-2, endothelin-3 , bombesin, cholecystokinin-8 or gastrin-releasing peptide. (C) 1998 F ederation of European Biochemical Societies.