Sequence and expression of a metabotropic glutamate receptor

The complementary DNA of a metabotropic glutamate receptor coupled to inositol phosphate/Ca²⁺ signal transduction has been cloned and characterized. This receptor shows no sequence similarity to conventional G protein-coupled receptors and has a unique structure with large hydrophilic sequences at both sides of seven putative membrane-spanning domains. Abundant expression of this messenger RNA is observed in neuronal cells in hippocampal dentate gyrus and CA2-3 and in cerebellar Purkinje cells, suggesting the importance of this receptor in specific hippocampal and cerebellar functions.