Cloning of a novel G-protein-coupled receptor from the sea anemone nervoussystem

We describe the cloning and analysis of genomic and cDNA copies of a gene f rom sea anemones that encodes a new member of the G-protein-coupled recepto r family. The receptor shows similarity to previously described receptors f or biogenic amines such as adrenaline, serotonin, and octopamine, as well a s a variety of small molecule agonists and peptides, although we have been unable to determine which ligand is the natural agonist. Antibodies generat ed against the recombinant receptor protein identify a single protein with a molecular weight of 66 kDa in membrane preparations. Immunofluorescence s tudies using the same antibody have enabled localization of the receptor in the nervous system. Western blotting and RT-PCR analysis reveal that a hom ologue of this receptor is expressed in jellyfish and soft coral. We sugges t that the receptor plays a role in neurotransmission in the sea anemone an d other members of the phylum Cnidaria. (C) 2000 Academic Press.