Sequence and expression of a novel GABAA receptor α subunit

AbstractCloned cDNA encoding the bovine α4 subunit of the GABAa receptor has been isolated. The predicted 521 amino acid long mature protein contains an exceptionally long intracellular domain and shares 53–56% sequence similarity to the previously characterized α1, α2 and α3, subunits. Co-expression of α4 and β1 in Xenopus oocytes resulted in the formation of GABA-gated chloride channels with expected pharmacology, although no benzodiazepine potentiation was observed. Northern analysis indicates that a 4 kb α4 mRNA is expressed in the calf cerebellum, cortex and hippocampus but is barely detectable in the rat brain