Article date: 1990/5/1
PubMed ID: 2157817
Journal name: Journal of neurochemistry (ISSN: 0022-3042)
A cDNA encoding a protein with 70% amino acid identity to the previously characterized gamma-aminobutyric acidA (GABAA) receptor alpha-subunits was isolated from a rat brain cDNA library by homology screening. As observed for alpha 1-, alpha 2-, and alpha 3-subunits, coexpression of this new alpha-subunit (alpha 5) with a beta- and gamma 2-subunit in cultured cells produces receptors displaying high-affinity binding sites for both muscimol, a GABA agonist, and benzodiazepines. Characteristic of GABAA/benzodiazepine type II sites, receptors containing alpha 2-, alpha 3- or alpha 5-subunits have low affinities for several type I-selective compounds. However, alpha 5-subunit-containing receptors have lower affinities for zolpidem (30-fold) and Cl 218 872 (three-fold) than measured previously using recombinantly expressed type II receptors containing either alpha 2- or alpha 3-subunits. Based on these findings, a reclassification of the GABAA/benzodiazepine receptors is warranted.
Author List: Pritchett D B, Seeburg P H
Publication Types: Journal Article; Research Support, Non-U.S. Gov't
Substances mentioned in the article: Ligands; Receptors, GABA-A; DNA;
Mesh terms: Animals; Base Sequence; Binding Sites; Binding, Competitive; Cell Line, Transformed; DNA/genetics; Humans; Kidney/cytology; Ligands; Molecular Sequence Data; Receptors, GABA-A/genetics;