Pharmacological hallmarks of allostery at the M4 muscarinic receptor elucidated through structure and dynamics
Ziva Vuckovic,
Jinan Wang,
Vi Pham,
Jesse I Mobbs,
Matthew J Belousoff,
Apurba Bhattarai,
Wessel AC Burger,
Geoff Thompson,
Mahmuda Yeasmin,
Vindhya Nawaratne,
Katie Leach,
Emma T van der Westhuizen,
Elham Khajehali,
Yi-Lynn Liang,
Alisa Glukhova,
Denise Wootten,
Craig W Lindsley,
Andrew Tobin,
Patrick Sexton,
Radostin Danev,
Celine Valant,
Yinglong Miao,
Arthur Christopoulos,
David M Thal
Affiliations
Ziva Vuckovic
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Jinan Wang
Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, Lawrence, United States
Vi Pham
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Jesse I Mobbs
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Matthew J Belousoff
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Apurba Bhattarai
Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, Lawrence, United States
Wessel AC Burger
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Geoff Thompson
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Mahmuda Yeasmin
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Vindhya Nawaratne
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Katie Leach
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Elham Khajehali
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Yi-Lynn Liang
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Alisa Glukhova
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Denise Wootten
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Craig W Lindsley
Department of Pharmacology, Warren Center for Neuroscience Drug Discovery and Department of Chemistry, Warren Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, United States
The Centre for Translational Pharmacology, Advanced Research Centre (ARC), College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
Patrick Sexton
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Radostin Danev
Graduate School of Medicine, University of Tokyo, Tokyo, Japan
Celine Valant
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Yinglong Miao
Center for Computational Biology and Department of Molecular Biosciences, University of Kansas, Lawrence, United States
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; Neuromedicines Discovery Centre, Monash University, Parkville, Australia
Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia; ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
Allosteric modulation of G protein-coupled receptors (GPCRs) is a major paradigm in drug discovery. Despite decades of research, a molecular-level understanding of the general principles that govern the myriad pharmacological effects exerted by GPCR allosteric modulators remains limited. The M4 muscarinic acetylcholine receptor (M4 mAChR) is a validated and clinically relevant allosteric drug target for several major psychiatric and cognitive disorders. In this study, we rigorously quantified the affinity, efficacy, and magnitude of modulation of two different positive allosteric modulators, LY2033298 (LY298) and VU0467154 (VU154), combined with the endogenous agonist acetylcholine (ACh) or the high-affinity agonist iperoxo (Ipx), at the human M4 mAChR. By determining the cryo-electron microscopy structures of the M4 mAChR, bound to a cognate Gi1 protein and in complex with ACh, Ipx, LY298-Ipx, and VU154-Ipx, and applying molecular dynamics simulations, we determine key molecular mechanisms underlying allosteric pharmacology. In addition to delineating the contribution of spatially distinct binding sites on observed pharmacology, our findings also revealed a vital role for orthosteric and allosteric ligand–receptor–transducer complex stability, mediated by conformational dynamics between these sites, in the ultimate determination of affinity, efficacy, cooperativity, probe dependence, and species variability. There results provide a holistic framework for further GPCR mechanistic studies and can aid in the discovery and design of future allosteric drugs.
