Cloning and expression of a novel rat GABAA receptor

Abstract
Two full‐length cDNA clones encoding α‐ and β‐subunits of a GABAA receptor have been isolated from a rat cerebral cortex cDNA library. The mature α‐subunit protein consists of 428 amino acids with a calculated M r of 48680. This protein is highly homologous (∼99% amino acid identity) with the bovine brain α1‐subunit receptor [(1988) Nature 335, 76–79]. The mature rat β‐subunit receptor is a 448 amino acid polypeptide and shares ∼ 80% amino acid identity with the previously characterized bovine GABAA receptor β‐subunit [(1987) Nature 328, 221–227]. Co‐expression of the cloned DNA in Xenopus oocytes produces a functional receptor and ion channel with pharmacological characteristics of a GABAA receptor. GABAA α‐ and β‐subunit mRNA is detectable in the cortex, cerebellum and hippocampus.