PT  - JOURNAL ARTICLE
AU  - Pritchett, DB
AU  - Luddens, H
AU  - Seeburg, PH
TI  - Type I and type II GABAA-benzodiazepine receptors produced in transfected cells
AID  - 10.1126/science.2551039
DP  - 1989 Sep 22
TA  - Science
PG  - 1389--1392
VI  - 245
IP  - 4924
4099  - http://science.sciencemag.org/content/245/4924/1389.short
4100  - http://science.sciencemag.org/content/245/4924/1389.full
SO  - Science1989 Sep 22; 245
AB  - GABAA (gamma-aminobutyric acid A)-benzodiazepine receptors expressed in mammalian cells and assembled from one of three different alpha subunit variants (alpha 1, alpha 2, or alpha 3) in combination with a beta 1 and a gamma 2 subunit display the pharmacological properties of either type I or type II receptor subtypes. These receptors contain high-affinity binding sites for benzodiazepines. However, CL 218 872, 2-oxoquazepam, and methyl beta-carboline-3-carboxylate (beta-CCM) show a temperature-modulated selectivity for alpha 1 subunit-containing receptors. There were no significant differences in the binding of clonazepam, diazepam, Ro 15-1788, or dimethoxy-4-ethyl-beta-carboline-3-carboxylate (DMCM) to all three recombinant receptors. Receptors containing the alpha 3 subunit show greater GABA potentiation of benzodiazepine binding than receptors containing the alpha 1 or alpha 2 subunit, indicating that there are subtypes within the type II class. Thus, diversity in benzodiazepine pharmacology is generated by heterogeneity of the alpha subunit of the GABAA receptor.