The point mutation gamma 2F77I changes the potency and efficacy of benzodiazepine site ligands in different GABAA receptor subtypes.

Article Details

Citation

Ramerstorfer J, Furtmuller R, Vogel E, Huck S, Sieghart W

The point mutation gamma 2F77I changes the potency and efficacy of benzodiazepine site ligands in different GABAA receptor subtypes.

Eur J Pharmacol. 2010 Jun 25;636(1-3):18-27. doi: 10.1016/j.ejphar.2010.03.015. Epub 2010 Mar 19.

PubMed ID
20303942 [ View in PubMed
]
Abstract

Benzodiazepine site agonists or inverse agonists enhance or reduce gamma-aminobutyric acid(A) (GABA(A)) receptor-mediated inhibition of neurons, respectively. Recently, it was demonstrated that the point mutation gamma 2F77I causes a drastic change in the affinity of a variety of benzodiazepine agonists or inverse agonists in receptor binding studies. Here we investigated the potency and efficacy of 10 benzodiazepine site ligands from 6 structural classes in wild-type and gamma 2F77I point mutated recombinant GABA(A) receptors composed of alpha 1 beta 3 gamma 2, alpha 2 beta 3 gamma 2, alpha 3 beta 3 gamma 2, alpha 4 beta 3 gamma 2, alpha 5 beta 3 gamma 2, and alpha 6 beta 3 gamma 2 subunits. Results indicate that the effects of the benzodiazepine site ligands zolpidem, zopiclone, Cl218872, L-655,708 and DMCM were nearly completely eliminated in all mutated receptors up to a 1 microM concentration. The effects of bretazenil, Ro15-1788 or abecarnil were eliminated in some, but not all mutated receptors, suggesting that the gamma 2F77I mutation differentially influences the actions of these ligands in different receptor subtypes. In addition, this point mutation also influences the efficacy of diazepam for enhancing GABA-induced chloride flux, suggesting that the amino acid residue gamma 2F77 might also be involved in the transduction of the effect of benzodiazepines from binding to gating. The application of these drugs in a novel mouse model is discussed.

DrugBank Data that Cites this Article

Drug Targets
DrugTargetKindOrganismPharmacological ActionActions
ZopicloneGamma-aminobutyric acid receptor subunit alpha-1ProteinHumans
Yes
Potentiator
Details
ZopicloneGamma-aminobutyric acid receptor subunit alpha-2ProteinHumans
Yes
Potentiator
Details
ZopicloneGamma-aminobutyric acid receptor subunit alpha-3ProteinHumans
Yes
Potentiator
Details
ZopicloneGamma-aminobutyric acid receptor subunit alpha-5ProteinHumans
Yes
Potentiator
Details