Identification of an Inhibitory Alcohol Binding Site in GABAA ρ1 Receptors

التفاصيل البيبلوغرافية
العنوان: Identification of an Inhibitory Alcohol Binding Site in GABAA ρ1 Receptors
المؤلفون: Edward J. Bertaccini, Madeline A. Cullins, James R. Trudell, Ui S. Lee, R. Adron Harris, Carlos I. Ruiz, Cecilia M. Borghese
المصدر: ACS Chemical Neuroscience. 7:100-108
بيانات النشر: American Chemical Society (ACS), 2015.
سنة النشر: 2015
مصطلحات موضوعية: Models, Molecular, 0301 basic medicine, Alcohol binding, Patch-Clamp Techniques, Microinjections, GABA Agents, Physiology, Stereochemistry, Cognitive Neuroscience, Biochemistry, Article, Protein Structure, Secondary, gamma-Aminobutyric acid, Xenopus laevis, 03 medical and health sciences, Transduction, Genetic, medicine, Animals, Binding site, Receptor, gamma-Aminobutyric Acid, Binding Sites, Dose-Response Relationship, Drug, Ethanol, Chemistry, GABAA receptor, Central Nervous System Depressants, Cell Biology, General Medicine, Receptors, GABA-A, Transmembrane domain, 030104 developmental biology, Mutagenesis, Site-Directed, Oocytes, Ligand-gated ion channel, Hexanols, Protein Binding, medicine.drug, Hexanol
الوصف: Alcohols inhibit γ-aminobutyric acid type A ρ1 receptor function. After introducing mutations in several positions of the second transmembrane helix in ρ1, we studied the effects of ethanol and hexanol on GABA responses using two-electrode voltage clamp electrophysiology in Xenopus laevis oocytes. The 6' mutations produced the following effects on ethanol and hexanol responses: small increase or no change (T6'M), increased inhibition (T6'V), and small potentiation (T6'Y and T6'F). The 5' mutations produced mainly increases in hexanol inhibition. Other mutations produced small (3' and 9') or no changes (2' and L277 in the first transmembrane domain) in alcohol effects. These results suggest an inhibitory alcohol binding site near the 6' position. Homology models of ρ1 receptors based on the X-ray structure of GluCl showed that the 2', 5', 6', and 9' residues were easily accessible from the ion pore, with 5' and 6' residues from neighboring subunits facing each other; L3' and L277 also faced the neighboring subunit. We tested ethanol through octanol on single and double mutated ρ1 receptors [ρ1(I15'S), ρ1(T6'Y), and ρ1(T6'Y,I15'S)] to further characterize the inhibitory alcohol pocket in the wild-type ρ1 receptor. The pocket can only bind relatively short-chain alcohols and is eliminated by introducing Y in the 6' position. Replacing the bulky 15' residue with a smaller side chain introduced a potentiating binding site, more sensitive to long-chain than to short-chain alcohols. In conclusion, the net alcohol effect on the ρ1 receptor is determined by the sum of its actions on inhibitory and potentiating sites.
تدمد: 1948-7193
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::01fea37dd590d34a86feeac7b1e6b856Test
https://doi.org/10.1021/acschemneuro.5b00246Test
حقوق: OPEN
رقم الانضمام: edsair.doi.dedup.....01fea37dd590d34a86feeac7b1e6b856
قاعدة البيانات: OpenAIRE