Medicine and Health Sciences Commons^™

Intersubunit Interactions At Putative Sites Of Ethanol Action In The M3 And M4 Domains Of The Nmda Receptor Glun1 And Glun2b Subunits, Robert W. Peoples, Hong Ren, Yulin Zhao

Biomedical Sciences Faculty Research and Publications

Background and Purpose: The N-methyl-D-aspartate (NMDA) receptor is an important target of alcohol action in the brain. Recent studies in this laboratory have demonstrated that alcohol-sensitive positions in the intersubunit interfaces of the M3 and M4 domains of GluN1 and GluN2A subunits interact with respect to ethanol sensitivity and receptor kinetics, and that alcohol-sensitive positions in the M domains of GluN2A and GluN2B subunits differ. In this study we tested for interactions among alcohol-sensitive positions at the M domain intersubunit interfaces in GluN1/GluN2B NMDA receptors.

Experimental Approach: We used whole-cell patch-clamp recording in tsA201 cells expressing tryptophan substitution mutants at …

Interactions Among Positions In The Third And Fourth Membrane-Associated Domains At The Intersubunit Interface Of The N-Methyl-D-Aspartate Receptor Forming Sites Of Alcohol Action, Hong Ren, Yulin Zhao, Donard S. Dwyer, Robert W. Peoples

Biomedical Sciences Faculty Research and Publications

The N-methyl-d-aspartate (NMDA) glutamate receptor is a major target of ethanol in the brain. Previous studies have identified positions in the third and fourth membrane-associated (M) domains of the NMDA receptor GluN1 and GluN2A subunits that influence alcohol sensitivity. The predicted structure of the NMDA receptor, based on that of the related GluA2 subunit, indicates a close apposition of the alcohol-sensitive positions in M3 and M4 between the two subunit types. We tested the hypothesis that these positions interact to regulate receptor kinetics and ethanol sensitivity by using dual substitution mutants. In single-substitution mutants, we found that a position …

Molecular Requirements For Ethanol Differential Allosteric Modulation Of Ligand-Gated Ion Channels Based On Selective G Beta Gamma Modulation, Gonzalo E. Yevenes, Gustavo Moraga-Cid, Ariel Avila, Leonardo Guzman, Maximiliano Figueroa, Robert W. Peoples, Luis G. Aguayo

Biomedical Sciences Faculty Research and Publications

It is now believed that the allosteric modulation produced by ethanol in glycine receptors (GlyRs) depends on alcohol binding to discrete sites within the protein structure. Thus, the differential ethanol sensitivity of diverse GlyR isoforms and mutants was explained by the presence of specific residues in putative alcohol pockets. Here, we demonstrate that ethanol sensitivity in two LGIC members, the GlyR adult alpha1 and embryonic alpha2 subunits, can be modified through selective mutations that rescued or impaired Gbetagamma modulation. Even though that both isoforms were able to physically interact with Gbetagamma, only the alpha1 GlyR was functionally modulated by Gbetagamma …

Differential Actions Of Ethanol And Trichloroethanol At Sites In The M3 And M4 Domains Of The Nmda Receptor Glun2a (Nr2a) Subunit, Ak Salous, H Ren, Ka Lamb, Xiang-Qun Hu, Rh Lipsky, Robert W. Peoples

Biomedical Sciences Faculty Research and Publications

Background and purpose:  Alcohol produces its behavioural effects in part due to inhibition of N-methyl-d-aspartate (NMDA) receptors in the CNS. Previous studies have identified amino acid residues in membrane-associated domains 3 (M3) and 4 (M4) of the NMDA receptor that influence ethanol sensitivity. In addition, in other alcohol-sensitive ion channels, sedative-hypnotic agents have in some cases been shown to act at sites distinct from the sites of ethanol action. In this study, we compared the influence of mutations at these sites on sensitivity to ethanol and trichloroethanol, a sedative-hypnotic agent that is a structural analogue of ethanol.

Experimental approach: …