TY - JOUR
T1 - GABAA receptor signalling mechanisms revealed by structural pharmacology
AU - Masiulis, Simonas
AU - Desai, Rooma
AU - Uchański, Tomasz
AU - Serna Martin, Itziar
AU - Laverty, Duncan
AU - Karia, Dimple
AU - Malinauskas, Tomas
AU - Zivanov, Jasenko
AU - Pardon, Els
AU - Kotecha, Abhay
AU - Steyaert, Jan
AU - Miller, Keith W.
AU - Aricescu, A. Radu
N1 - Funding Information:
Acknowledgements We thank G. Cannone and S. Chen for cryo-EM assistance at the MRC-LMB; Y. Chaban and K. Dent for cryo-EM assistance at the Electron Bio-Imaging Centre (eBIC), Diamond Light Source; J. García-Nafría, L. Dong, T. Nakane and S. Scheres for advice on cryo-EM data processing; J. Grimmett and T. Darling for IT and computing support; and members of the Aricescu laboratory for discussions and comments on the manuscript. This work was supported by the UK Medical Research Council grants MR/ L009609/1, MC_UP_1201/15 (A.R.A., S.M. and D.L.) and MC_UP_A025_1013 (J.Z.); UK Biotechnology and Biological Sciences Research Council grant BB/M024709/1 (A.R.A. and D.L.); Human Frontier Science Program grant RGP0065/2014 (A.R.A.); Cancer Research UK grant C20724/A14414 (T.M.); and Swiss National Science Foundation fellowship 168735 (J.Z.). R.D. and K.W.M. were supported by a grant from the National Institute for General Medical Sciences (GM 58448) and by the Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital. We acknowledge the support and the use of resources of Instruct-ERIC (PID1271), part of the European Strategy Forum on Research Infrastructures (ESFRI), and the Research Foundation-Flanders (FWO) for their support of nanobody discovery, and FWO for a doctoral fellowship to T.U.
Publisher Copyright:
© 2019, Springer Nature Limited.
PY - 2019/1/24
Y1 - 2019/1/24
N2 - Type-A γ-aminobutyric (GABAA) receptors are ligand-gated chloride channels with a very rich pharmacology. Some of their modulators, including benzodiazepines and general anaesthetics, are among the most successful drugs in clinical use and are common substances of abuse. Without reliable structural data, the mechanistic basis for the pharmacological modulation of GABAA receptors remains largely unknown. Here we report several high-resolution cryo-electron microscopy structures in which the full-length human α1β3γ2L GABAA receptor in lipid nanodiscs is bound to the channel-blocker picrotoxin, the competitive antagonist bicuculline, the agonist GABA (γ-aminobutyric acid), and the classical benzodiazepines alprazolam and diazepam. We describe the binding modes and mechanistic effects of these ligands, the closed and desensitized states of the GABAA receptor gating cycle, and the basis for allosteric coupling between the extracellular, agonist-binding region and the transmembrane, pore-forming region. This work provides a structural framework in which to integrate previous physiology and pharmacology research and a rational basis for the development of GABAA receptor modulators.
AB - Type-A γ-aminobutyric (GABAA) receptors are ligand-gated chloride channels with a very rich pharmacology. Some of their modulators, including benzodiazepines and general anaesthetics, are among the most successful drugs in clinical use and are common substances of abuse. Without reliable structural data, the mechanistic basis for the pharmacological modulation of GABAA receptors remains largely unknown. Here we report several high-resolution cryo-electron microscopy structures in which the full-length human α1β3γ2L GABAA receptor in lipid nanodiscs is bound to the channel-blocker picrotoxin, the competitive antagonist bicuculline, the agonist GABA (γ-aminobutyric acid), and the classical benzodiazepines alprazolam and diazepam. We describe the binding modes and mechanistic effects of these ligands, the closed and desensitized states of the GABAA receptor gating cycle, and the basis for allosteric coupling between the extracellular, agonist-binding region and the transmembrane, pore-forming region. This work provides a structural framework in which to integrate previous physiology and pharmacology research and a rational basis for the development of GABAA receptor modulators.
UR - http://www.scopus.com/inward/record.url?scp=85060365964&partnerID=8YFLogxK
U2 - 10.1038/s41586-018-0832-5
DO - 10.1038/s41586-018-0832-5
M3 - Article
C2 - 30602790
AN - SCOPUS:85060365964
SN - 0028-0836
VL - 565
SP - 454
EP - 459
JO - Nature
JF - Nature
IS - 7740
ER -