Abstract
G protein-coupled receptors (GPCRs) are the largest human membrane protein family that transduce extracellular signals into cellular responses. They are major pharmacological targets, with approximately 26% of marketed drugs targeting GPCRs, primarily at their orthosteric binding site. Despite their prominence, predicting the pharmacological effects of novel GPCR-targeting drugs remains challenging due to the complex functional dynamics of these receptors. Recent advances in X-ray crystallography, cryo-electron microscopy, spectroscopic techniques and molecular simulations have enhanced our understanding of receptor conformational dynamics and ligand interactions with GPCRs. These developments have revealed novel ligand-binding modes, mechanisms of action and druggable pockets. In this Review, we highlight such aspects for recently discovered small-molecule drugs and drug candidates targeting GPCRs, focusing on three categories: allosteric modulators, biased ligands, and bivalent and bitopic compounds. Although studies so far have largely been retrospective, integrating structural data on ligand-induced receptor functional dynamics into the drug discovery pipeline has the potential to guide the identification of drug candidates with specific abilities to modulate GPCR interactions with intracellular effector proteins such as G proteins and β-arrestins, enabling more tailored selectivity and efficacy profiles.
This is a preview of subscription content, access via your institution
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$32.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Lander, E. S. et al. Initial sequencing and analysis of the human genome. Nature 409, 860–921 (2001).
Hauser, A. S., Attwood, M. M., Rask-Andersen, M., Schiöth, H. B. & Gloriam, D. E. Trends in GPCR drug discovery: new agents, targets and indications. Nat. Rev. Drug Discov. 16, 829–842 (2017).
Santos, R. et al. A comprehensive map of molecular drug targets. Nat. Rev. Drug Discov. 16, 19–34 (2017).
Sriram, K. & Insel, P. A. G protein-coupled receptors as targets for approved drugs: how many targets and how many drugs? Mol. Pharmacol. 93, 251–258 (2018).
Wu, G. GPCR-targeting drugs: a renewed focus on a ubiquitous group of proteins. BioPharma Dive (7 March 2023).
Schmidt, C. Septerna: making another run on GPCRs. Nat. Biotechnol. https://doi.org/10.1038/d41587-023-00010-y (2023).
Summary of NDA approvals & receipts, 1938 to the present. US Food and Drug Administration (FDA) https://fda.gov/about-fda/histories-fda-regulated-products/summary-nda-approvals-receipts-1938-present (2023).
Kenakin, T. G-protein coupled receptors as allosteric machines. Recept. Channels 10, 51–60 (2004).
Latorraca, N. R., Venkatakrishnan, A. J. & Dror, R. O. GPCR dynamics: structures in motion. Chem. Rev. 117, 139–155 (2017).
Weis, W. I. & Kobilka, B. K. The molecular basis of G protein–coupled receptor activation. Annu. Rev. Biochem. 87, 897–919 (2018).
Hilger, D., Masureel, M. & Kobilka, B. K. Structure and dynamics of GPCR signaling complexes. Nat. Struct. Mol. Biol. 25, 4–12 (2018).
Gurevich, V. V. & Gurevich, E. V. Biased GPCR signaling: possible mechanisms and inherent limitations. Pharmacol. Ther. 211, 107540 (2020).
Sutkeviciute, I. & Vilardaga, J.-P. Structural insights into emergent signaling modes of G protein-coupled receptors. J. Biol. Chem. 295, 11626–11642 (2020).
García-Nafría, J. & Tate, C. G. Cryo-EM structures of GPCRs coupled to Gs, Gi and Go. Mol. Cell. Endocrinol. 488, 1–13 (2019).
Christopoulos, A. et al. International union of basic and clinical pharmacology. XC. Multisite pharmacology: recommendations for the nomenclature of receptor allosterism and allosteric ligands. Pharmacol. Rev. 66, 918–947 (2014).
Chatzigoulas, A. & Cournia, Z. Rational design of allosteric modulators: challenges and successes. Wiley Interdiscip. Rev. Comput. Mol. Sci. 11, e1529 (2021).
Ye, L., Van Eps, N., Zimmer, M., Ernst, O. P. & Prosser, R. S. Activation of the A2A adenosine G-protein-coupled receptor by conformational selection. Nature 533, 265–268 (2016).
Ye, L. et al. Mechanistic insights into allosteric regulation of the A2A adenosine G protein-coupled receptor by physiological cations. Nat. Commun. 9, 1372 (2018).
Sušac, L., Eddy, M. T., Didenko, T., Stevens, R. C. & Wüthrich, K. A2A adenosine receptor functional states characterized by 19F-NMR. Proc. Natl Acad. Sci. USA 115, 12733–12738 (2018).
Eddy, M. T. et al. Allosteric coupling of drug binding and intracellular signaling in the A2A adenosine receptor. Cell 172, 68–80.e12 (2018).
Huang, S. K. & Prosser, R. S. Dynamics and mechanistic underpinnings to pharmacology of class A GPCRs: an NMR perspective. Am. J. Physiol. Cell Physiol. 322, C739–C753 (2022).
Wei, S. et al. Single-molecule visualization of human A2A adenosine receptor activation by a G protein and constitutively activating mutations. Commun. Biol. 6, 1218 (2023).
Wang, X., Neale, C., Kim, S.-K., Goddard, W. A. & Ye, L. Intermediate-state-trapped mutants pinpoint G protein-coupled receptor conformational allostery. Nat. Commun. 14, 1325 (2023).
Shimada, I., Ueda, T., Kofuku, Y., Eddy, M. T. & Wüthrich, K. GPCR drug discovery: integrating solution NMR data with crystal and cryo-EM structures. Nat. Rev. Drug Discov. 18, 59–82 (2019).
Huang, S. K. et al. Mapping the conformational landscape of the stimulatory heterotrimeric G protein. Nat. Struct. Mol. Biol. 30, 502–511 (2023).
Huang, S. K. et al. Delineating the conformational landscape of the adenosine A2A receptor during G protein coupling. Cell 184, 1884–1894.e14 (2021).
Jones, A. J. Y. et al. Binding kinetics drive G protein subtype selectivity at the β1-adrenergic receptor. Nat. Commun. 15, 1334 (2024).
Solt, A. S. et al. Insight into partial agonism by observing multiple equilibria for ligand-bound and Gs-mimetic nanobody-bound β1-adrenergic receptor. Nat. Commun. 8, 1795 (2017).
Isogai, S. et al. Backbone NMR reveals allosteric signal transduction networks in the β1-adrenergic receptor. Nature 530, 237–241 (2016).
Papasergi-Scott, M. M. et al. Time-resolved cryo-EM of G-protein activation by a GPCR. Nature 629, 1182–1191 (2024).
Manglik, A. et al. Structural insights into the dynamic process of β2-adrenergic receptor signaling. Cell 161, 1101–1111 (2015).
Calderón, J. C., Ibrahim, P., Gobbo, D., Gervasio, F. L. & Clark, T. General metadynamics protocol to simulate activation/deactivation of class a GPCRs: proof of principle for the serotonin receptor. J. Chem. Inf. Model. 63, 3105–3117 (2023).
Di Marino, D., Conflitti, P., Motta, S. & Limongelli, V. Structural basis of dimerization of chemokine receptors CCR5 and CXCR4. Nat. Commun. 14, 6439 (2023).
D’Amore, V. M., Conflitti, P., Marinelli, L. & Limongelli, V. Minute-timescale free-energy calculations reveal a pseudo-active state in the adenosine A2A receptor activation mechanism. Chem https://doi.org/10.1016/j.chempr.2024.08.004 (2024).
Raniolo, S. & Limongelli, V. Ligand binding free-energy calculations with funnel metadynamics. Nat. Protoc. 15, 2837–2866 (2020).
Souza, P. C. T. et al. Protein–ligand binding with the coarse-grained Martini model. Nat. Commun. 11, 3714 (2020).
Conflitti, P., Raniolo, S. & Limongelli, V. Perspectives on ligand/protein binding kinetics simulations: force fields, machine learning, sampling, and user-friendliness. J. Chem. Theory Comput. 19, 6047–6061 (2023).
Limongelli, V. Ligand binding free energy and kinetics calculation in 2020. Wiley Interdiscip. Rev. Comput. Mol. Sci. 10, e1455 (2020).
Jespers, W. et al. Deciphering conformational selectivity in the A2A adenosine G protein-coupled receptor by free energy simulations. PLoS Comput. Biol. 17, e1009152 (2021).
Panel, N. et al. Design of drug efficacy guided by free energy simulations of the β2-adrenoceptor. Angew. Chem. Int. Ed. 62, e202218959 (2023).
Vögele, M., Zhang, B. W., Kaindl, J. & Wang, L. Is the functional response of a receptor determined by the thermodynamics of ligand binding? J. Chem. Theory Comput. 19, 8414–8422 (2023).
Wang, X. et al. Characterization of cancer-related somatic mutations in the adenosine A2B receptor. Eur. J. Pharmacol. 880, 173126 (2020).
Bongers, B. J. et al. Pan-cancer functional analysis of somatic mutations in G protein-coupled receptors. Sci. Rep. 12, 21534 (2022).
Yuan, X., Raniolo, S., Limongelli, V. & Xu, Y. The molecular mechanism underlying ligand binding to the membrane-embedded site of a G-protein-coupled receptor. J. Chem. Theory Comput. 14, 2761–2770 (2018).
Hollingsworth, S. A. et al. Cryptic pocket formation underlies allosteric modulator selectivity at muscarinic GPCRs. Nat. Commun. 10, 3289 (2019).
Meller, A., Kelly, D., Smith, L. G. & Bowman, G. R. Toward physics-based precision medicine: exploiting protein dynamics to design new therapeutics and interpret variants. Protein Sci. 33, e4902 (2024).
Fredriksson, R., Lagerström, M. C., Lundin, L.-G. & Schiöth, H. B. The G-protein-coupled receptors in the human genome form five main families. Phylogenetic analysis, paralogon groups, and fingerprints. Mol. Pharmacol. 63, 1256–1272 (2003).
Isberg, V. et al. GPCRdb: an information system for G protein-coupled receptors. Nucleic Acids Res. 44, D356–D364 (2016).
Xu, P. et al. Structural insights into the lipid and ligand regulation of serotonin receptors. Nature 592, 469–473 (2021).
Lin, X. et al. Structural basis of ligand recognition and self-activation of orphan GPR52. Nature 579, 152–157 (2020).
Palczewski, K. et al. Crystal structure of rhodopsin: a G protein-coupled receptor. Science 289, 739–745 (2000).
Park, J. H., Scheerer, P., Hofmann, K. P., Choe, H.-W. & Ernst, O. P. Crystal structure of the ligand-free G-protein-coupled receptor opsin. Nature 454, 183–187 (2008).
Samama, P., Cotecchia, S., Costa, T. & Lefkowitz, R. J. A mutation-induced activated state of the beta 2-adrenergic receptor. Extending the ternary complex model. J. Biol. Chem. 268, 4625–4636 (1993).
Pándy-Szekeres, G. et al. GproteinDb in 2024: new G protein-GPCR couplings, AlphaFold2-multimer models and interface interactions. Nucleic Acids Res. 52, D466–D475 (2024).
Rasmussen, S. G. F. et al. Crystal structure of the β2 adrenergic receptor–Gs protein complex. Nature 477, 549–555 (2011).
Gurevich, V. V. & Gurevich, E. V. Plethora of functions packed into 45 kDa arrestins: biological implications and possible therapeutic strategies. Cell. Mol. Life Sci. 76, 4413–4421 (2019).
Laporte, S. A. & Scott, M. G. H. in Beta-Arrestins. Methods in Molecular Biology, Vol. 1957 (eds Scott, M. G. H. & Laporte, S. A.) 9–55 (Humana Press, 2019).
Xiao, K. et al. Functional specialization of β-arrestin interactions revealed by proteomic analysis. Proc. Natl Acad. Sci. USA 104, 12011–12016 (2007).
Hauser, A. S. et al. GPCR activation mechanisms across classes and macro/microscales. Nat. Struct. Mol. Biol. 28, 879–888 (2021).
Nygaard, R. et al. The dynamic process of β2-adrenergic receptor activation. Cell 152, 532–542 (2013).
Gregorio, G. G. et al. Single-molecule analysis of ligand efficacy in β2AR–G-protein activation. Nature 547, 68–73 (2017).
Rose, A. S. et al. Position of transmembrane helix 6 determines receptor G protein coupling specificity. J. Am. Chem. Soc. 136, 11244–11247 (2014).
Batebi, H. et al. Mechanistic insights into G-protein coupling with an agonist-bound G-protein-coupled receptor. Nat. Struct. Mol. Biol. 31, 1692–1701 (2024).
Hilger, D. et al. Structural insights into differences in G protein activation by family A and family B GPCRs. Science 369, eaba3373 (2020).
Kato, H. E. et al. Conformational transitions of a neurotensin receptor 1–Gi1 complex. Nature 572, 80–85 (2019).
Sounier, R. et al. Propagation of conformational changes during μ-opioid receptor activation. Nature 524, 375–378 (2015).
Onaran, H. O. & Costa, T. Allosteric coupling and conformational fluctuations in proteins. Curr. Protein Pept. Sci. 10, 110–115 (2009).
Grahl, A., Abiko, L. A., Isogai, S., Sharpe, T. & Grzesiek, S. A high-resolution description of β1-adrenergic receptor functional dynamics and allosteric coupling from backbone NMR. Nat. Commun. 11, 2216 (2020).
Mafi, A., Kim, S.-K. & Goddard, W. A. The mechanism for ligand activation of the GPCR–G protein complex. Proc. Natl Acad. Sci. USA 119, e2110085119 (2022).
Mafi, A., Kim, S.-K. & Goddard, W. A. The dynamics of agonist-β2-adrenergic receptor activation induced by binding of GDP-bound Gs protein. Nat. Chem. 15, 1127–1137 (2023).
Devree, B. T. et al. Allosteric coupling from G protein to the agonist-binding pocket in GPCRs. Nature 535, 182–186 (2016).
Warne, T., Edwards, P. C., Doré, A. S., Leslie, A. G. W. & Tate, C. G. Molecular basis for high-affinity agonist binding in GPCRs. Science 364, 775–778 (2019).
Nygaard, R., Frimurer, T. M., Holst, B., Rosenkilde, M. M. & Schwartz, T. W. Ligand binding and micro-switches in 7TM receptor structures. Trends Pharmacol. Sci. 30, 249–259 (2009).
Zhou, Q. et al. Common activation mechanism of class A GPCRs. eLife 8, e50279 (2019).
Wang, J., Hua, T. & Liu, Z.-J. Structural features of activated GPCR signaling complexes. Curr. Opin. Struct. Biol. 63, 82–89 (2020).
Isberg, V. et al. Generic GPCR residue numbers – aligning topology maps while minding the gaps. Trends Pharmacol. Sci. 36, 22–31 (2015).
Ballesteros, J. A. & Weinstein, H. in Methods in Neurosciences, Vol. 25 (ed. Sealfon, S. C.) 366–428 (Academic Press, 1995).
Wootten, D., Simms, J., Miller, L. J., Christopoulos, A. & Sexton, P. M. Polar transmembrane interactions drive formation of ligand-specific and signal pathway-biased family B G protein-coupled receptor conformations. Proc. Natl Acad. Sci. USA 110, 5211–5216 (2013).
Pin, J.-P., Galvez, T. & Prézeau, L. Evolution, structure, and activation mechanism of family 3/C G-protein-coupled receptors. Pharmacol. Ther. 98, 325–354 (2003).
Wang, C. et al. Structural basis for Smoothened receptor modulation and chemoresistance to anticancer drugs. Nat. Commun. 5, 4355 (2014).
Gutiérrez-de-Terán, H. et al. The role of a sodium ion binding site in the allosteric modulation of the A2A adenosine G protein-coupled receptor. Structure 21, 2175–2185 (2013).
Bjornsson, T. D. et al. The conduct of in vitro and in vivo drug-drug interaction studies: a pharmaceutical research and manufacturers of America (PhRMA) perspective. Drug Metab. Dispos. 31, 815–832 (2003).
Wienkers, L. C. & Heath, T. G. Predicting in vivo drug interactions from in vitro drug discovery data. Nat. Rev. Drug Discov. 4, 825–833 (2005).
Noetzel, M. J. et al. Functional impact of allosteric agonist activity of selective positive allosteric modulators of metabotropic glutamate receptor subtype 5 in regulating central nervous system function. Mol. Pharmacol. 81, 120–133 (2012).
Kobayashi, K. et al. Class B1 GPCR activation by an intracellular agonist. Nature 615, 1085–1093 (2023).
Zhao, L.-H. et al. Conserved class B GPCR activation by a biased intracellular agonist. Nature 621, 635–641 (2023).
Kruse, A. C. et al. Activation and allosteric modulation of a muscarinic acetylcholine receptor. Nature 504, 101–106 (2013).
Dror, R. O. et al. Structural basis for modulation of a G-protein-coupled receptor by allosteric drugs. Nature 503, 295–299 (2013).
Kruse, A. C. et al. Structure and dynamics of the M3 muscarinic acetylcholine receptor. Nature 482, 552–556 (2012).
Thal, D. M. et al. Crystal structures of the M1 and M4 muscarinic acetylcholine receptors. Nature 531, 335–340 (2016).
Wu, Y, Tong, J, Ding, K, Zhou, Q & Zhao, S. in Protein Allostery in Drug Discovery. Advances in Experimental Medicine and Biology, Vol. 1163 (eds Zhang, J. & Nussinov, R.) 225–251 (Springer, 2019).
Zhu, C., Lan, X., Wei, Z., Yu, J. & Zhang, J. Allosteric modulation of G protein-coupled receptors as a novel therapeutic strategy in neuropathic pain. Acta Pharm. Sin. B 14, 67–86 (2024).
He, J. et al. ASD2023: towards the integrating landscapes of allosteric knowledgebase. Nucleic Acids Res. 52, D376–D383 (2024).
Teng, X. et al. Ligand recognition and biased agonism of the D1 dopamine receptor. Nat. Commun. 13, 3186 (2022).
Krumm, B. E. et al. Neurotensin receptor allosterism revealed in complex with a biased allosteric modulator. Biochemistry 62, 1233–1248 (2023).
Saleh, N. et al. Multiple binding sites contribute to the mechanism of mixed agonistic and positive allosteric modulators of the cannabinoid CB1 receptor. Angew. Chem. Int. Ed. 57, 2580–2585 (2018).
Hurst, D. P. et al. Identification of CB1 receptor allosteric sites using force-biased MMC simulated annealing and validation by structure–activity relationship studies. ACS Med. Chem. Lett. 10, 1216–1221 (2019).
Hao, J. et al. Synthesis and pharmacological characterization of 2-(2,6-dichlorophenyl)-1-((1S,3R)-5-(3-hydroxy-3-methylbutyl)-3-(hydroxymethyl)-1-methyl-3,4-dihydroisoquinolin-2(1H)-yl)ethan-1-one (LY3154207), a potent, subtype selective, and orally available positive allosteric modulator of the human dopamine D1 receptor. J. Med. Chem. 62, 8711–8732 (2019).
Xiao, P. et al. Ligand recognition and allosteric regulation of DRD1-Gs signaling complexes. Cell 184, 943–956.e18 (2021).
Liu, X. et al. An allosteric modulator binds to a conformational hub in the β2 adrenergic receptor. Nat. Chem. Biol. 16, 749–755 (2020).
Song, G. et al. Human GLP-1 receptor transmembrane domain structure in complex with allosteric modulators. Nature 546, 312–315 (2017).
Wu, H. et al. Structure of a class C GPCR metabotropic glutamate receptor 1 bound to an allosteric modulator. Science 344, 58–64 (2014).
Du, J. et al. Structures of human mGlu2 and mGlu7 homo- and heterodimers. Nature 594, 589–593 (2021).
Nasrallah, C. et al. Agonists and allosteric modulators promote signaling from different metabotropic glutamate receptor 5 conformations. Cell Rep. 36, 109648 (2021).
Gao, Y. et al. Asymmetric activation of the calcium-sensing receptor homodimer. Nature 595, 455–459 (2021).
Shao, Z. et al. Structure of an allosteric modulator bound to the CB1 cannabinoid receptor. Nat. Chem. Biol. 15, 1199–1205 (2019).
Park, J. et al. Symmetric activation and modulation of the human calcium-sensing receptor. Proc. Natl Acad. Sci. USA 118, e2115849118 (2021).
Oswald, C. et al. Intracellular allosteric antagonism of the CCR9 receptor. Nature 540, 462–465 (2016).
Zheng, Y. et al. Structure of CC chemokine receptor 2 with orthosteric and allosteric antagonists. Nature 540, 458–461 (2016).
Abiko, L. A. et al. Filling of a water-free void explains the allosteric regulation of the β1-adrenergic receptor by cholesterol. Nat. Chem. 14, 1133–1141 (2022).
Slosky, L. M., Caron, M. G. & Barak, L. S. Biased allosteric modulators: new frontiers in GPCR drug discovery. Trends Pharmacol. Sci. 42, 283–299 (2021).
Cheng, R. K. Y. et al. Structural insight into allosteric modulation of protease-activated receptor 2. Nature 545, 112–115 (2017).
Maeda, S., Qu, Q., Robertson, M. J., Skiniotis, G. & Kobilka, B. K. Structures of the M1 and M2 muscarinic acetylcholine receptor/G-protein complexes. Science 364, 552–557 (2019).
Liu, X. et al. Mechanism of β2AR regulation by an intracellular positive allosteric modulator. Science 364, 1283–1287 (2019).
Staus, D. P. et al. Structure of the M2 muscarinic receptor–β-arrestin complex in a lipid nanodisc. Nature 579, 297–302 (2020).
Duan, J. et al. Structures of full-length glycoprotein hormone receptor signalling complexes. Nature 598, 688–692 (2021).
Wang, J. et al. The unconventional activation of the muscarinic acetylcholine receptor M4R by diverse ligands. Nat. Commun. 13, 2855 (2022).
Duan, J. et al. Hormone- and antibody-mediated activation of the thyrotropin receptor. Nature 609, 854–859 (2022).
Vuckovic, Z. et al. Pharmacological hallmarks of allostery at the M4 muscarinic receptor elucidated through structure and dynamics. eLife 12, e83477 (2023).
Xu, J. et al. Structural and dynamic insights into supra-physiological activation and allosteric modulation of a muscarinic acetylcholine receptor. Nat. Commun. 14, 376 (2023).
Liu, Y. et al. Ligand recognition and allosteric modulation of the human MRGPRX1 receptor. Nat. Chem. Biol. 19, 416–422 (2023).
Duan, J. et al. GPCR activation and GRK2 assembly by a biased intracellular agonist. Nature 620, 676–681 (2023).
Duan, J. et al. Mechanism of hormone and allosteric agonist mediated activation of follicle stimulating hormone receptor. Nat. Commun. 14, 519 (2023).
Lu, J. et al. Structural basis for the cooperative allosteric activation of the free fatty acid receptor GPR40. Nat. Struct. Mol. Biol. 24, 570–577 (2017).
Yang, F. et al. Structural basis of GPBAR activation and bile acid recognition. Nature 587, 499–504 (2020).
Zhuang, Y. et al. Mechanism of dopamine binding and allosteric modulation of the human D1 dopamine receptor. Cell Res. 31, 593–596 (2021).
Liu, X. et al. Mechanism of intracellular allosteric β2AR antagonist revealed by X-ray crystal structure. Nature 548, 480–484 (2017).
Jaeger, K. et al. Structural basis for allosteric ligand recognition in the human CC chemokine receptor 7. Cell 178, 1222–1230.e10 (2019).
Liu, K. et al. Structural basis of CXC chemokine receptor 2 activation and signalling. Nature 585, 135–140 (2020).
Jazayeri, A. et al. Extra-helical binding site of a glucagon receptor antagonist. Nature 533, 274–277 (2016).
Zhang, H. et al. Structure of the full-length glucagon class B G-protein-coupled receptor. Nature 546, 259–264 (2017).
Wu, F. et al. Full-length human GLP-1 receptor structure without orthosteric ligands. Nat. Commun. 11, 1272 (2020).
Cong, Z. et al. Molecular insights into ago-allosteric modulation of the human glucagon-like peptide-1 receptor. Nat. Commun. 12, 3763 (2021).
Hollenstein, K. et al. Structure of class B GPCR corticotropin-releasing factor receptor 1. Nature 499, 438–443 (2013).
Kim, H. et al. Structure-based drug discovery of a corticotropin-releasing hormone receptor 1 antagonist using an X-ray free-electron laser. Exp. Mol. Med. 55, 2039–2050 (2023).
Ling, S. Structural insights into asymmetric activation of the calcium-sensing receptor–Gq complex. Cell Res. 34, 169–172 (2023).
Krishna, K. K. et al. Stepwise activation of a metabotropic glutamate receptor. Nature 629, 951–956 (2024).
Christopher, J. A. et al. Fragment and structure-based drug discovery for a class C GPCR: discovery of the mGlu5 negative allosteric modulator HTL14242 (3-chloro-5-[6-(5-fluoropyridin-2-yl)pyrimidin-4-yl]benzonitrile). J. Med. Chem. 58, 6553–6664 (2015).
Christopher, J. A. et al. Structure-based optimization strategies for G protein-coupled receptor (GPCR) allosteric modulators: a case study from analyses of new metabotropic glutamate receptor 5 (mGlu5) X-ray structures. J. Med. Chem. 62, 207–222 (2019).
Lin, S. et al. Structures of Gi-bound metabotropic glutamate receptors mGlu2 and mGlu4. Nature 594, 583–588 (2021).
Seven, A. B. et al. G-protein activation by a metabotropic glutamate receptor. Nature 595, 450–454 (2021).
Wen, T. et al. Structural basis for activation and allosteric modulation of full-length calcium-sensing receptor. Sci. Adv. 7, eabg1483 (2021).
Wang, X. et al. Structural insights into dimerization and activation of the mGlu2–mGlu3 and mGlu2–mGlu4 heterodimers. Cell Res. 33, 762–774 (2023).
Doré, A. S. et al. Structure of class C GPCR metabotropic glutamate receptor 5 transmembrane domain. Nature 511, 557–562 (2014).
Svensson, K. A. et al. An allosteric potentiator of the dopamine D1 receptor increases locomotor activity in human D1 knock-in mice without causing stereotypy or tachyphylaxis. J. Pharmacol. Exp. Ther. 360, 117–128 (2017).
Bruns, R. F. et al. Preclinical profile of a dopamine D1 potentiator suggests therapeutic utility in neurological and psychiatric disorders. Neuropharmacology 128, 351–365 (2018).
Wilbraham, D., Biglan, K. M., Svensson, K. A., Tsai, M. & Kielbasa, W. Safety, tolerability, and pharmacokinetics of mevidalen (LY3154207), a centrally acting dopamine D1 receptor-positive allosteric modulator (D1PAM), in healthy subjects. Clin. Pharmacol. Drug Dev. 10, 393–403 (2021).
US National Library of Medicine. ClinicalTrials.gov https://clinicaltrials.gov/study/NCT03305809 (2021).
Biglan, K. et al. Safety and efficacy of mevidalen in Lewy body dementia: a phase 2, randomized, placebo-controlled trial. Mov. Disord. 37, 513–524 (2022).
Teng, X. et al. Structural insights into G protein activation by D1 dopamine receptor. Sci. Adv. 8, eabo4158 (2022).
Laprairie, R. B. et al. Enantiospecific allosteric modulation of cannabinoid 1 receptor. ACS Chem. Neurosci. 8, 1188–1203 (2017).
Mackie, K. Cannabinoid receptors as therapeutic targets. Annu. Rev. Pharmacol. Toxicol. 46, 101–122 (2006).
Mackie, K. Cannabinoid receptors: where they are and what they do. J. Neuroendocrinol. 20, 10–14 (2008).
Shahbazi, F., Grandi, V., Banerjee, A. & Trant, J. F. Cannabinoids and cannabinoid receptors: the story so far. iScience 23, 101301 (2020).
Price, M. R. et al. Allosteric modulation of the cannabinoid CB1 receptor. Mol. Pharmacol. 68, 1484–1495 (2005).
Horswill, J. G. et al. PSNCBAM-1, a novel allosteric antagonist at cannabinoid CB1 receptors with hypophagic effects in rats. Br. J. Pharmacol. 152, 805–814 (2007).
Laprairie, R. B. et al. Positive allosteric modulation of the type 1 cannabinoid receptor reduces the signs and symptoms of Huntington’s disease in the R6/2 mouse model. Neuropharmacology 151, 1–12 (2019).
Slivicki, R. A. et al. Positive allosteric modulation of CB1 cannabinoid receptor signaling enhances morphine antinociception and attenuates morphine tolerance without enhancing morphine- induced dependence or reward. Front. Mol. Neurosci. 13, 54 (2020).
Garai, S. et al. Application of fluorine- and nitrogen-walk approaches: defining the structural and functional diversity of 2-phenylindole class of cannabinoid 1 receptor positive allosteric modulators. J. Med. Chem. 63, 542–568 (2020).
Garai, S. et al. Discovery of a biased allosteric modulator for cannabinoid 1 receptor: preclinical anti-glaucoma efficacy. J. Med. Chem. 64, 8104–8126 (2021).
Dowie, M. J. et al. Altered CB1 receptor and endocannabinoid levels precede motor symptom onset in a transgenic mouse model of Huntington’s disease. Neuroscience 163, 456–465 (2009).
Hua, T. et al. Crystal structures of agonist-bound human cannabinoid receptor CB1. Nature 547, 468–471 (2017).
Drug Approval Package: Sensipar https://accessdata.fda.gov/drugsatfda_docs/nda/2004/21-688_Sensipar.cfm (2004).
Block, G. A. et al. Cinacalcet for secondary hyperparathyroidism in patients receiving hemodialysis. N. Engl. J. Med. 350, 1516–1525 (2004).
Nemeth, E. F. et al. Pharmacodynamics of the type II calcimimetic compound cinacalcet HCl. J. Pharmacol. Exp. Ther. 308, 627–635 (2004).
Peacock, M. et al. Cinacalcet hydrochloride maintains long-term normocalcemia in patients with primary hyperparathyroidism. J. Clin. Endocrinol. Metab. 90, 135–141 (2005).
Nemeth, E. F., Van Wagenen, B. C. & Balandrin, M. F. in Progress in Medicinal Chemistry, Vol. 57 (eds Witty, D. R. & Cox, B.) 1–86 (Elsevier, 2018).
Nemeth, E. F. et al. Calcimimetics with potent and selective activity on the parathyroid calcium receptor. Proc. Natl Acad. Sci. USA 95, 4040–4045 (1998).
McConnachie, L. et al. Human liver cytochrome P450 2D6 genotype, full-length messenger ribonucleic acid, and activity assessed with a novel cytochrome P450 2D6 substrate. Clin. Pharmacol. Ther. 75, 282–297 (2004).
Fukagawa, M., Shimazaki, R. & Akizawa, T. Head-to-head comparison of the new calcimimetic agent evocalcet with cinacalcet in Japanese hemodialysis patients with secondary hyperparathyroidism. Kidney Int. 94, 818–825 (2018).
US National Library of Medicine. ClinicalTrials.gov https://clinicaltrials.gov/study/NCT03280264 (2021).
Takeuchi, Y., Nishida, Y., Kondo, Y., Imanishi, Y. & Fukumoto, S. Evocalcet in patients with primary hyperparathyroidism: an open-label, single-arm, multicenter, 52-week, dose-titration phase III study. J. Bone Miner. Metab. 38, 687–694 (2020).
Wess, J., Eglen, R. M. & Gautam, D. Muscarinic acetylcholine receptors: mutant mice provide new insights for drug development. Nat. Rev. Drug Discov. 6, 721–733 (2007).
Kruse, A. C. et al. Muscarinic acetylcholine receptors: novel opportunities for drug development. Nat. Rev. Drug Discov. 13, 549–560 (2014).
Foster, D. J., Jones, C. K. & Conn, P. J. Emerging approaches for treatment of schizophrenia: modulation of cholinergic signaling. Discov. Med. 14, 413–420 (2012).
Burger, W. A. C. et al. Xanomeline displays concomitant orthosteric and allosteric binding modes at the M4 mAChR. Nat. Commun. 14, 5440 (2023).
FDA approves drug with new mechanism of action for treatment of schizophrenia. US Food and Drug Administration (FDA) https://fda.gov/news-events/press-announcements/fda-approves-drug-new-mechanism-action-treatment-schizophrenia (2024).
Madsbad, S. Review of head-to-head comparisons of glucagon-like peptide-1 receptor agonists. Diabetes Obes. Metab. 18, 317–332 (2016).
Andersen, A., Lund, A., Knop, F. K. & Vilsbøll, T. Glucagon-like peptide 1 in health and disease. Nat. Rev. Endocrinol. 14, 390–403 (2018).
Drucker, D. J. Mechanisms of action and therapeutic application of glucagon-like peptide-1. Cell Metab. 27, 740–756 (2018).
Marso, S. P. et al. Semaglutide and cardiovascular outcomes in patients with type 2 diabetes. N. Engl. J. Med. 375, 1834–1844 (2016).
Knudsen, L. B. & Lau, J. The discovery and development of liraglutide and semaglutide. Front. Endocrinol. 10, 155 (2019).
Wilding, J. P. H. et al. Once-weekly semaglutide in adults with overweight or obesity. N. Engl. J. Med. 384, 989–1002 (2021).
Lincoff, A. M. et al. Semaglutide and cardiovascular outcomes in obesity without diabetes. N. Engl. J. Med. 389, 2221–2232 (2023).
Weghuber, D. et al. Once-weekly semaglutide in adolescents with obesity. N. Engl. J. Med. 387, 2245–2257 (2022).
Sodhi, M., Rezaeianzadeh, R., Kezouh, A. & Etminan, M. Risk of gastrointestinal adverse events associated with glucagon-like peptide-1 receptor agonists for weight loss. JAMA 330, 1795–1797 (2023).
Lindsley, C. W. & Niswender, K. Positive allosteric modulators of the glp-1 receptor. Patent WO2017117556A1 (2017).
Tamiya, J. et al. Novel glp-1 receptor modulators. Patent WO2018200833A1 (2018).
Koole, C. et al. Differential impact of amino acid substitutions on critical residues of the human glucagon-like peptide-1 receptor involved in peptide activity and small-molecule allostery. J. Pharmacol. Exp. Ther. 353, 52–63 (2015).
Boehm, M. F. et al. Glp-1 receptor modulators. Patent WO2016094729A1 (2016).
Bueno, A. B. et al. Positive allosteric modulation of the glucagon-like peptide-1 receptor by diverse electrophiles. J. Biol. Chem. 291, 10700–10715 (2016).
Méndez, M. et al. Design, synthesis, and pharmacological evaluation of potent positive allosteric modulators of the glucagon-like peptide-1 receptor (GLP-1R). J. Med. Chem. 63, 2292–2307 (2020).
Bueno, A. B. et al. Structural insights into probe-dependent positive allosterism of the GLP-1 receptor. Nat. Chem. Biol. 16, 1105–1110 (2020).
Willard, F. S. et al. Discovery of an orally efficacious positive allosteric modulator of the glucagon-like peptide-1 receptor. J. Med. Chem. 64, 3439–3448 (2021).
Xin, Y. et al. Affinity selection of double-click triazole libraries for rapid discovery of allosteric modulators for GLP-1 receptor. Proc. Natl Acad. Sci. USA 120, e2220767120 (2023).
Pinkerton, A. B. et al. Discovery of β-arrestin biased, orally bioavailable, and CNS penetrant neurotensin receptor 1 (NTR1) allosteric modulators. J. Med. Chem. 62, 8357–8363 (2019).
Slosky, L. M. et al. β-Arrestin-biased allosteric modulator of NTSR1 selectively attenuates addictive behaviors. Cell 181, 1364–1379.e14 (2020).
Peddibhotla, S. et al. Discovery of ML314, a brain penetrant nonpeptidic β-arrestin biased agonist of the neurotensin NTR1 receptor. ACS Med. Chem. Lett. 4, 846–851 (2013).
Porter-Stransky, K. A. & Weinshenker, D. Arresting the development of addiction: the role of β-arrestin 2 in drug abuse. J. Pharmacol. Exp. Ther. 361, 341–348 (2017).
Barak, L. S. et al. ML314: a biased neurotensin receptor ligand for methamphetamine abuse. ACS Chem. Biol. 11, 1880–1890 (2016).
Ferraro, L. et al. Neurotensin: a role in substance use disorder? J. Psychopharmacol. 30, 112–127 (2016).
Iyer, M. R. & Kunos, G. Therapeutic approaches targeting the neurotensin receptors. Expert Opin. Ther. Pat. 31, 361–386 (2021).
Huang, W. et al. Structure of the neurotensin receptor 1 in complex with β-arrestin 1. Nature 579, 303–308 (2020).
FDA approves add-on drug for adults with rare form of blood vessel inflammation. US Food and Drug Administration (FDA) https://fda.gov/drugs/news-events-human-drugs/fda-approves-add-drug-adults-rare-form-blood-vessel-inflammation (2021).
Lee, A. Avacopan: first approval. Drugs 82, 79–85 (2022).
Jayne, D. R. W., Merkel, P. A., Schall, T. J. & Bekker, P. Avacopan for the treatment of ANCA-associated vasculitis. N. Engl. J. Med. 384, 599–609 (2021).
Monk, P. N., Scola, A.-M., Madala, P. & Fairlie, D. P. Function, structure and therapeutic potential of complement C5a receptors. Br. J. Pharmacol. 152, 429–448 (2007).
Bekker, P. et al. Characterization of pharmacologic and pharmacokinetic properties of CCX168, a potent and selective orally administered complement 5a receptor inhibitor, based on preclinical evaluation and randomized phase 1 clinical study. PLoS ONE 11, e0164646 (2016).
Liu, H. et al. Orthosteric and allosteric action of the C5a receptor antagonists. Nat. Struct. Mol. Biol. 25, 472–481 (2018).
Dasse, O. A. et al. Novel, acidic CCR2 receptor antagonists: lead optimization. Lett. Drug Des. Discov. 4, 263–271 (2007).
Walters, M. J. et al. Characterization of CCX282-B, an orally bioavailable antagonist of the ccr9 chemokine receptor, for treatment of inflammatory bowel disease. J. Pharmacol. Exp. Ther. 335, 61–69 (2010).
Feagan, B. G. et al. Randomised clinical trial: vercirnon, an oral CCR9 antagonist, vs. placebo as induction therapy in active Crohn’s disease. Aliment. Pharmacol. Ther. 42, 1170–1181 (2015).
Ortiz Zacarías, N. V. et al. Synthesis and pharmacological evaluation of triazolopyrimidinone derivatives as noncompetitive, intracellular antagonists for CC chemokine receptors 2 and 5. J. Med. Chem. 62, 11035–11053 (2019).
Ortiz Zacarías, N. V. et al. Design and characterization of an intracellular covalent ligand for CC chemokine receptor 2. J. Med. Chem. 64, 2608–2621 (2021).
Toy, L., Huber, M. E., Schmidt, M. F., Weikert, D. & Schiedel, M. Fluorescent ligands targeting the intracellular allosteric binding site of the chemokine receptor CCR2. ACS Chem. Biol. 17, 2142–2152 (2022).
Huber, M. E., Toy, L., Schmidt, M. F., Weikert, D. & Schiedel, M. Small molecule tools to study cellular target engagement for the intracellular allosteric binding site of GPCRs. Chem. Eur. J. 29, e202202565 (2023).
US National Library of Medicine. ClinicalTrials.gov https://clinicaltrials.gov/study/NCT03473925 (2022).
Armstrong, A. J. et al. CXCR2 antagonist navarixin in combination with pembrolizumab in select advanced solid tumors: a phase 2 randomized trial. Invest. New Drugs 42, 145–159 (2024).
Huber, M. E. et al. A chemical biology toolbox targeting the intracellular binding site of ccr9: fluorescent ligands, new drug leads and PROTACs. Angew. Chem. Int. Ed. 61, e202116782 (2022).
Caroli, J. et al. A community Biased Signaling Atlas. Nat. Chem. Biol. 19, 531–535 (2023).
Kolb, P. et al. Community guidelines for GPCR ligand bias: IUPHAR review 32. Br. J. Pharmacol. 179, 3651–3674 (2022).
Wang, X., McFarland, A., Madsen, J. J., Aalo, E. & Ye, L. The potential of 19F NMR application in GPCR biased drug discovery. Trends Pharmacol. Sci. 42, 19–30 (2021).
Kelly, E., Conibear, A. E. & Henderson, G. Biased agonism: lessons from studies of opioid receptor agonists. Annu. Rev. Pharmacol. Toxicol. 63, 491–515 (2022).
Nagi, K. & Pineyro, G. Practical guide for calculating and representing biased signaling by GPCR ligands: a stepwise approach. Methods 92, 78–86 (2016).
Onaran, H. O. et al. Systematic errors in detecting biased agonism: analysis of current methods and development of a new model-free approach. Sci. Rep. 7, 44247 (2017).
Wootten, D., Christopoulos, A., Marti-Solano, M., Babu, M. M. & Sexton, P. M. Mechanisms of signalling and biased agonism in G protein-coupled receptors. Nat. Rev. Mol. Cell Biol. 19, 638–653 (2018).
Cecon, E., Oishi, A. & Jockers, R. Melatonin receptors: molecular pharmacology and signalling in the context of system bias. Br. J. Pharmacol. 175, 3263–3280 (2018).
Herenbrink, C. K. et al. The role of kinetic context in apparent biased agonism at GPCRs. Nat. Commun. 7, 10842 (2016).
Ursu, O. et al. DrugCentral: online drug compendium. Nucleic Acids Res. 45, D932–D939 (2017).
Alexander, S. P. H. et al. The concise guide to pharmacology 2021/22: G protein-coupled receptors. Br. J. Pharmacol. 178, S27–S156 (2021).
FDA approves new opioid for intravenous use in hospitals, other controlled clinical settings. US Food and Drug Administration (FDA) https://fda.gov/news-events/press-announcements/fda-approves-new-opioid-intravenous-use-hospitals-other-controlled-clinical-settings (2020).
Markham, A. Oliceridine: first approval. Drugs 80, 1739–1744 (2020).
Lambert, D. & Calo, G. Approval of oliceridine (TRV130) for intravenous use in moderate to severe pain in adults. Br. J. Anaesth. 125, e473–e474 (2020).
DeWire, S. M. et al. A G protein-biased ligand at the μ-opioid receptor is potently analgesic with reduced gastrointestinal and respiratory dysfunction compared with morphine. J. Pharmacol. Exp. Ther. 344, 708–717 (2013).
Azzam, A. A. H., McDonald, J. & Lambert, D. G. Hot topics in opioid pharmacology: mixed and biased opioids. Br. J. Anaesth. 122, e136–e145 (2019).
Singla, N. K. et al. APOLLO-2: a randomized, placebo and active-controlled phase III study investigating oliceridine (TRV130), a G protein–biased ligand at the μ-opioid receptor, for management of moderate to severe acute pain following abdominoplasty. Pain Pract. 19, 715–731 (2019).
Schneider, S., Provasi, D. & Filizola, M. How oliceridine (TRV-130) binds and stabilizes a μ-opioid receptor conformational state that selectively triggers G protein signaling pathways. Biochemistry 55, 6456–6466 (2016).
Zhuang, Y. et al. Molecular recognition of morphine and fentanyl by the human μ-opioid receptor. Cell 185, 4361–4375.e19 (2022).
Lee, Y. et al. Molecular basis of β-arrestin coupling to formoterol-bound β1-adrenoceptor. Nature 583, 862–866 (2020).
Cao, C. et al. Signaling snapshots of a serotonin receptor activated by the prototypical psychedelic LSD. Neuron 110, 3154–3167.e7 (2022).
Bous, J. et al. Structure of the vasopressin hormone–V2 receptor–β-arrestin1 ternary complex. Sci. Adv. 8, eabo7761 (2022).
Wall, M. J. et al. Selective activation of Gαob by an adenosine A1 receptor agonist elicits analgesia without cardiorespiratory depression. Nat. Commun. 13, 4150 (2022).
Chen, J.-F., Eltzschig, H. K. & Fredholm, B. B. Adenosine receptors as drug targets — what are the challenges? Nat. Rev. Drug Discov. 12, 265–286 (2013).
Jacobson, K. A. & Müller, C. E. Medicinal chemistry of adenosine, P2Y and P2X receptors. Neuropharmacology 104, 31–49 (2016).
Borea, P. A., Gessi, S., Merighi, S., Vincenzi, F. & Varani, K. Pharmacology of adenosine receptors: the state of the art. Physiol. Rev. 98, 1591–1625 (2018).
Gomes, I. et al. Biased signaling by endogenous opioid peptides. Proc. Natl Acad. Sci. USA 117, 11820–11828 (2020).
Olsen, R. H. J. et al. TRUPATH, an open-source biosensor platform for interrogating the GPCR transducerome. Nat. Chem. Biol. 16, 841–849 (2020).
Kawai, Y. & Arinze, I. J. Differential localization and development-dependent expression of G-protein subunits, Goα and Gβ, in rabbit heart. J. Mol. Cell. Cardiol. 28, 1555–1564 (1996).
McGrath, M. F. & de Bold, A. J. Transcriptional analysis of the mammalian heart with special reference to its endocrine function. BMC Genom. 10, 254 (2009).
Kawahara, K., Hohjoh, H., Inazumi, T., Tsuchiya, S. & Sugimoto, Y. Prostaglandin E2-induced inflammation: relevance of prostaglandin E receptors. Biochim. Biophys. Acta Mol. Cell Biol. Lipids 1851, 414–421 (2015).
Tsuge, K., Inazumi, T., Shimamoto, A. & Sugimoto, Y. Molecular mechanisms underlying prostaglandin E2-exacerbated inflammation and immune diseases. Int. Immunol. 31, 597–606 (2019).
Yokoyama, U., Iwatsubo, K., Umemura, M., Fujita, T. & Ishikawa, Y. The prostanoid EP4 receptor and its signaling pathway. Pharmacol. Rev. 65, 1010–1052 (2013).
Li, J. H. et al. A selective EP4 PGE2 receptor agonist alleviates disease in a new mouse model of X-linked nephrogenic diabetes insipidus. J. Clin. Invest. 119, 3115–3126 (2009).
Xu, H. et al. Endothelial cell prostaglandin E2 receptor EP4 is essential for blood pressure homeostasis. JCI Insight 5, e138505 (2020).
Xu, H. et al. VSMC-specific EP4 deletion exacerbates angiotensin II-induced aortic dissection by increasing vascular inflammation and blood pressure. Proc. Natl Acad. Sci. USA 116, 8457–8462 (2019).
Luschnig-Schratl, P. et al. EP4 receptor stimulation down-regulates human eosinophil function. Cell. Mol. Life Sci. 68, 3573–3587 (2011).
Huang, S.-M. et al. Single hormone or synthetic agonist induces Gs/Gi coupling selectivity of EP receptors via distinct binding modes and propagating paths. Proc. Natl Acad. Sci. USA 120, e2216329120 (2023).
Nakase, H. et al. Effect of EP4 agonist (ONO-4819CD) for patients with mild to moderate ulcerative colitis refractory to 5-aminosalicylates: a randomized phase II, placebo-controlled trial. Inflamm. Bowel Dis. 16, 731–733 (2010).
Foudi, N. et al. Vasorelaxation induced by prostaglandin E2 in human pulmonary vein: role of the EP4 receptor subtype. Br. J. Pharmacol. 154, 1631–1639 (2008).
Qiao, A. et al. Structural basis of Gs and Gi recognition by the human glucagon receptor. Science 367, 1346–1352 (2020).
Gusach, A., García-Nafría, J. & Tate, C. New insights into GPCR coupling and dimerisation from cryo-EM structures. Curr. Opin. Struct. Biol. 80, 102574 (2023).
Cheloha, R. W., Gellman, S. H., Vilardaga, J.-P. & Gardella, T. J. PTH receptor-1 signalling — mechanistic insights and therapeutic prospects. Nat. Rev. Endocrinol. 11, 712–724 (2015).
Vilardaga, J.-P., Romero, G., Friedman, P. A. & Gardella, T. J. Molecular basis of parathyroid hormone receptor signaling and trafficking: a family B GPCR paradigm. Cell. Mol. Life Sci. 68, 1–13 (2011).
Blaine, J., Chonchol, M. & Levi, M. Renal control of calcium, phosphate, and magnesium homeostasis. Clin. J. Am. Soc. Nephrol. 10, 1257–1272 (2015).
Pettway, G. J. et al. Parathyroid hormone mediates bone growth through the regulation of osteoblast proliferation and differentiation. Bone 42, 806–818 (2008).
Fan, Y. et al. Parathyroid hormone directs bone marrow mesenchymal cell fate. Cell Metab. 25, 661–672 (2017).
Balani, D. H., Ono, N. & Kronenberg, H. M. Parathyroid hormone regulates fates of murine osteoblast precursors in vivo. J. Clin. Invest. 127, 3327–3338 (2017).
Okazaki, M. et al. Prolonged signaling at the parathyroid hormone receptor by peptide ligands targeted to a specific receptor conformation. Proc. Natl Acad. Sci. USA 105, 16525–16530 (2008).
Maeda, A. et al. Critical role of parathyroid hormone (PTH) receptor-1 phosphorylation in regulating acute responses to PTH. Proc. Natl Acad. Sci. USA 110, 5864–5869 (2013).
Gesty-Palmer, D. et al. A β-arrestin–biased agonist of the parathyroid hormone receptor (PTH1R) promotes bone formation independent of G protein activation. Sci. Transl. Med. 1, 1ra1 (2009).
Tamura, T. et al. Identification of an orally active small-molecule PTHR1 agonist for the treatment of hypoparathyroidism. Nat. Commun. 7, 13384 (2016).
Nishimura, Y. et al. Lead optimization and avoidance of reactive metabolite leading to PCO371, a potent, selective, and orally available human parathyroid hormone receptor 1 (hPTHR1) agonist. J. Med. Chem. 63, 5089–5099 (2020).
US National Library of Medicine. ClinicalTrials.gov https://clinicaltrials.gov/study/NCT04649216 (2021).
US National Library of Medicine. ClinicalTrials.gov https://clinicaltrials.gov/study/NCT04209179 (2021).
US National Library of Medicine. ClinicalTrials.gov https://clinicaltrials.gov/study/NCT02475616 (2015).
Erez, M., Takemori, A. E. & Portoghese, P. S. Narcotic antagonistic potency of bivalent ligands which contain .beta.-naltrexamine. Evidence for simultaneous occupation of proximal recognition sites. J. Med. Chem. 25, 847–849 (1982).
Gomes, I. et al. G protein–coupled receptor heteromers. Annu. Rev. Pharmacol. Toxicol. 56, 403–425 (2016).
Farran, B. An update on the physiological and therapeutic relevance of GPCR oligomers. Pharmacol. Res. 117, 303–327 (2017).
Işbilir, A. et al. Advanced fluorescence microscopy reveals disruption of dynamic CXCR4 dimerization by subpocket-specific inverse agonists. Proc. Natl Acad. Sci. USA 117, 29144–29154 (2020).
Dale, N. C., Johnstone, E. K. M. & Pfleger, K. D. G. GPCR heteromers: an overview of their classification, function and physiological relevance. Front. Endocrinol. 13, 931573 (2022).
Newman, A. H., Battiti, F. O. & Bonifazi, A. 2016 Philip S. Portoghese medicinal chemistry lectureship: designing bivalent or bitopic molecules for G-protein coupled receptors. The whole is greater than the sum of its parts. J. Med. Chem. 63, 1779–1797 (2020).
González-Maeso, J. et al. Identification of a serotonin/glutamate receptor complex implicated in psychosis. Nature 452, 93–97 (2008).
Fribourg, M. et al. Decoding the signaling of a GPCR heteromeric complex reveals a unifying mechanism of action of antipsychotic drugs. Cell 147, 1011–1023 (2011).
de Bartolomeis, A., Buonaguro, E. F. & Iasevoli, F. Serotonin–glutamate and serotonin–dopamine reciprocal interactions as putative molecular targets for novel antipsychotic treatments: from receptor heterodimers to postsynaptic scaffolding and effector proteins. Psychopharmacology 225, 1–19 (2013).
Ferré, S. et al. Allosteric mechanisms within the adenosine A2A–dopamine D2 receptor heterotetramer. Neuropharmacology 104, 154–160 (2016).
Navarro, G. et al. Evidence for functional pre-coupled complexes of receptor heteromers and adenylyl cyclase. Nat. Commun. 9, 1242 (2018).
Pulido, D. et al. Heterobivalent ligand for the adenosine A2A–dopamine D2 receptor heteromer. J. Med. Chem. 65, 616–632 (2022).
Chun, L., Zhang, W. & Liu, J. Structure and ligand recognition of class C GPCRs. Acta Pharmacol. Sin. 33, 312–323 (2012).
Im, D. et al. Structure of the dopamine D2 receptor in complex with the antipsychotic drug spiperone. Nat. Commun. 11, 6442 (2020).
Orru, M. et al. Striatal pre- and postsynaptic profile of adenosine A2A receptor antagonists. PLoS ONE 6, e16088 (2011).
Sabbadin, D., Ciancetta, A., Deganutti, G., Cuzzolin, A. & Moro, S. Exploring the recognition pathway at the human A2A adenosine receptor of the endogenous agonist adenosine using supervised molecular dynamics simulations. MedChemComm 6, 1081–1085 (2015).
Fronik, P., Gaiser, B. I. & Sejer Pedersen, D. Bitopic ligands and metastable binding sites: opportunities for G protein-coupled receptor (GPCR) medicinal chemistry. J. Med. Chem. 60, 4126–4134 (2017).
Lane, J. R., Sexton, P. M. & Christopoulos, A. Bridging the gap: bitopic ligands of G-protein-coupled receptors. Trends Pharmacol. Sci. 34, 59–66 (2013).
Valant, C., Lane, J. R., Sexton, P. & Christopoulos, A. The best of both worlds? Bitopic orthosteric/allosteric ligands of g protein-coupled receptors. Annu. Rev. Pharmacol. Toxicol. 52, 153–178 (2012).
Drug Approval Package: Serevent https://accessdata.fda.gov/drugsatfda_docs/nda/98/20692S1,2_Serevent.cfm (1998).
Soulele, K., Macheras, P. & Karalis, V. Pharmacokinetic analysis of inhaled salmeterol in asthma patients: evidence from two dry powder inhalers. Biopharm. Drug Dispos. 38, 407–419 (2017).
Cazzola, M., Testi, R. & Matera, M. G. Clinical pharmacokinetics of salmeterol. Clin. Pharmacokinet. 41, 19–30 (2002).
Masureel, M. et al. Structural insights into binding specificity, efficacy and bias of a β2AR partial agonist. Nat. Chem. Biol. 14, 1059–1066 (2018).
Carter, A. A. & Hill, S. J. Characterization of isoprenaline- and salmeterol-stimulated interactions between β2-adrenoceptors and β-arrestin 2 using β-galactosidase complementation in C2C12 cells. J. Pharmacol. Exp. Ther. 315, 839–848 (2005).
Drake, M. T. et al. β-Arrestin-biased agonism at the β2-adrenergic receptor. J. Biol. Chem. 283, 5669–5676 (2008).
Liapakis, G., Chan, W. C., Papadokostaki, M. & Javitch, J. A. Synergistic contributions of the functional groups of epinephrine to its affinity and efficacy at the β2 adrenergic receptor. Mol. Pharmacol. 65, 1181–1190 (2004).
Faouzi, A. et al. Structure-based design of bitopic ligands for the µ-opioid receptor. Nature 613, 767–774 (2023).
Gado, F. Design, synthesis, and biological activity of new CB2 receptor ligands: from orthosteric and allosteric modulators to dualsteric/bitopic ligands. J. Med. Chem. 65, 9918–9938 (2022).
Gaiser, B. I. et al. Probing the existence of a metastable binding site at the β2-adrenergic receptor with homobivalent bitopic ligands. J. Med. Chem. 62, 7806–7839 (2019).
Valant, C. et al. Separation of on-target efficacy from adverse effects through rational design of a bitopic adenosine receptor agonist. Proc. Natl Acad. Sci. USA 111, 4614–4619 (2014).
Tan, L. et al. Design and synthesis of bitopic 2-phenylcyclopropylmethylamine (PCPMA) derivatives as selective dopamine D3 receptor ligands. J. Med. Chem. 63, 4579–4602 (2020).
Shaik, A. B. et al. Structure activity relationships for a series of eticlopride-based dopamine D2/D3 receptor bitopic ligands. J. Med. Chem. 64, 15313–15333 (2021).
Agasid, M. T., Sørensen, L., Urner, L. H., Yan, J. & Robinson, C. V. The effects of sodium ions on ligand binding and conformational states of G protein-coupled receptors — insights from mass spectrometry. J. Am. Chem. Soc. 143, 4085–4089 (2021).
Katritch, V. et al. Allosteric sodium in class A GPCR signaling. Trends Biochem. Sci. 39, 233–244 (2014).
Fenalti, G. et al. Molecular control of δ-opioid receptor signalling. Nature 506, 191–196 (2014).
Huang, W. et al. Structural insights into µ-opioid receptor activation. Nature 524, 315–321 (2015).
Schmid, C. L. et al. Bias factor and therapeutic window correlate to predict safer opioid analgesics. Cell 171, 1165–1175.e13 (2017).
Ramos-Gonzalez, N. et al. Carfentanil is a β-arrestin-biased agonist at the μ opioid receptor. Br. J. Pharmacol. 180, 2341–2360 (2023).
Lückmann, M. et al. Molecular dynamics-guided discovery of an ago-allosteric modulator for GPR40/FFAR1. Proc. Natl Acad. Sci. USA 116, 7123–7128 (2019).
Yadav, P., Mollaei, P., Cao, Z., Wang, Y. & Barati Farimani, A. Prediction of GPCR activity using machine learning. Comput. Struct. Biotechnol. J. 20, 2564–2573 (2022).
Pándy-Szekeres, G. et al. GPCRdb in 2023: state-specific structure models using AlphaFold2 and new ligand resources. Nucleic Acids Res. 51, D395–D402 (2023).
Lyu, J. et al. AlphaFold2 structures guide prospective ligand discovery. Science 384, eadn6354 (2024).
Calderón, J. C., Ibrahim, P., Gobbo, D., Gervasio, F. L. & Clark, T. Determinants of neutral antagonism and inverse agonism in the β2-adrenergic receptor. J. Chem. Inf. Model. 64, 2045–2057 (2024).
Hori, T. et al. Na+-mimicking ligands stabilize the inactive state of leukotriene B4 receptor BLT1. Nat. Chem. Biol. 14, 262–269 (2018).
Chen, K.-Y. M., Keri, D. & Barth, P. Computational design of G protein-coupled receptor allosteric signal transductions. Nat. Chem. Biol. 16, 77–86 (2020).
Abiko, L. A. et al. Biased agonism of carvedilol in the β1-adrenergic receptor is governed by conformational exclusion. Preprint at bioRxiv https://doi.org/10.1101/2024.07.19.604263 (2024).
Kooistra, A. J., Munk, C., Hauser, A. S. & Gloriam, D. E. An online GPCR structure analysis platform. Nat. Struct. Mol. Biol. 28, 875–878 (2021).
Rodríguez-Espigares, I. et al. GPCRmd uncovers the dynamics of the 3D-GPCRome. Nat. Methods 17, 777–787 (2020).
Taracena Herrera, L. P. et al. GPCRdb in 2025: adding odorant receptors, data mapper, structure similarity search and models of physiological ligand complexes. Nucl. Acids Res. https://doi.org/10.1093/nar/gkae1065 (2024).
Yin, J. et al. Structure of a D2 dopamine receptor–G-protein complex in a lipid membrane. Nature 584, 125–129 (2020).
de Felice, A., Aureli, S. & Limongelli, V. Drug repurposing on G protein-coupled receptors using a computational profiling approach. Front. Mol. Biosci. 8, 673053 (2021).
Kim, K. et al. Structure of a hallucinogen-activated Gq-coupled 5-HT2A serotonin receptor. Cell 182, 1574–1588.e19 (2020).
Martínez-Muñoz, L. et al. CCR5/CD4/CXCR4 oligomerization prevents HIV-1 gp120IIIB binding to the cell surface. Proc. Natl Acad. Sci. USA 111, E1960–E1969 (2014).
Martínez-Muñoz, L. et al. Separating actin-dependent chemokine receptor nanoclustering from dimerization indicates a role for clustering in CXCR4 signaling and function. Mol. Cell 70, 106–119.e10 (2018).
Jin, J. et al. CCR5 adopts three homodimeric conformations that control cell surface delivery. Sci. Signal. 11, eaal2869 (2018).
Zhang, L., Zhang, J.-T., Hang, L. & Liu, T. Mu opioid receptor heterodimers emerge as novel therapeutic targets: recent progress and future perspective. Front. Pharmacol. 11, 1078 (2020).
Parmar, V. K., Grinde, E., Mazurkiewicz, J. E. & Herrick-Davis, K. Beta2-adrenergic receptor homodimers: role of transmembrane domain 1 and helix 8 in dimerization and cell surface expression. Biochim. Biophys. Acta Biomembr. 1859, 1445–1455 (2017).
Martínez-Muñoz, L., Villares, R., Rodríguez-Fernández, J. L., Rodríguez-Frade, J. M. & Mellado, M. Remodeling our concept of chemokine receptor function: from monomers to oligomers. J. Leukoc. Biol. 104, 323–331 (2018).
Salanga, C. L., O’Hayre, M. & Handel, T. Modulation of chemokine receptor activity through dimerization and crosstalk. Cell. Mol. Life Sci. 66, 1370–1386 (2009).
Paradis, J. S. et al. Computationally designed GPCR quaternary structures bias signaling pathway activation. Nat. Commun. 13, 6826 (2022).
Borroni, E. M., Mantovani, A., Locati, M. & Bonecchi, R. Chemokine receptors intracellular trafficking. Pharmacol. Ther. 127, 1–8 (2010).
Ward, R. J. et al. Chemokine receptor CXCR4 oligomerization is disrupted selectively by the antagonist ligand IT1t. J. Biol. Chem. 296, 100139 (2021).
Brelot, A. & Chakrabarti, L. A. CCR5 revisited: how mechanisms of HIV entry govern AIDS pathogenesis. J. Mol. Biol. 430, 2557–2589 (2018).
Haqqani, A. A. & Tilton, J. C. Entry inhibitors and their use in the treatment of HIV-1 infection. Antivir. Res. 98, 158–170 (2013).
Van Der Ryst, E. Maraviroc – a CCR5 antagonist for the treatment of HIV-1 infection. Front. Immunol. 6, 277 (2015).
Tan, Q. et al. Structure of the CCR5 chemokine receptor–HIV entry inhibitor maraviroc complex. Science 341, 1387–1390 (2013).
Rouault, A. A. J. et al. The GPCR accessory protein MRAP2 regulates both biased signaling and constitutive activity of the ghrelin receptor GHSR1a. Sci. Signal. 13, eaax4569 (2020).
Rouault, A. A. J., Srinivasan, D. K., Yin, T. C., Lee, A. A. & Sebag, J. A. Melanocortin receptor accessory proteins (MRAPs): functions in the melanocortin system and beyond. Biochim. Biophys. Acta Mol. Basis Dis. 1863, 2462–2467 (2017).
Fan, S., Liu, H. & Li, L. The REEP family of proteins: molecular targets and role in pathophysiology. Pharmacol. Res. 185, 106477 (2022).
Hay, D. L. & Pioszak, A. A. Receptor activity-modifying proteins (RAMPs): new insights and roles. Annu. Rev. Pharmacol. Toxicol. 56, 469–487 (2016).
Gingell, J. J. et al. An allosteric role for receptor activity-modifying proteins in defining GPCR pharmacology. Cell Discov. 2, 16012 (2016).
Hay, D. L. et al. Receptor activity-modifying proteins; multifunctional G protein-coupled receptor accessory proteins. Biochem. Soc. Trans. 44, 568–573 (2016).
Kotliar, I. B., Lorenzen, E., Schwenk, J. M., Hay, D. L. & Sakmar, T. P. Elucidating the interactome of G protein-coupled receptors and receptor activity-modifying proteins. Pharmacol. Rev. 75, 1–34 (2023).
Pert, C. B., Pasternak, G. & Snyder, S. H. Opiate agonists and antagonists discriminated by receptor binding in brain. Science 182, 1359–1361 (1973).
Snyder, S. H. & Pasternak, G. W. Historical review: opioid receptors. Trends Pharmacol. Sci. 24, 198–205 (2003).
Miller-Gallacher, J. L. et al. The 2.1 Å resolution structure of cyanopindolol-bound β1-adrenoceptor identifies an intramembrane Na+ ion that stabilises the ligand-free receptor. PLoS ONE 9, e92727 (2014).
Zhang, C. et al. High-resolution crystal structure of human protease-activated receptor 1. Nature 492, 387–392 (2012).
White, K. L. et al. Structural connection between activation microswitch and allosteric sodium site in GPCR signaling. Structure 26, 259–269.e5 (2018).
Chan, H. C. S. et al. Enhancing the signaling of GPCRs via orthosteric ions. ACS Cent. Sci. 6, 274–282 (2020).
Rodriguez, F. D., Bardaji, E. & Traynor, J. R. Differential effects of Mg2+ and other divalent cations on the binding of tritiated opioid ligands. J. Neurochem. 59, 467–472 (1992).
Zou, R. et al. The role of metal ions in G protein-coupled receptor signalling and drug discovery. Wiley Interdiscip. Rev. Comput. Mol. Sci. 12, e1565 (2022).
Hu, X., Provasi, D., Ramsey, S. & Filizola, M. Mechanism of μ-opioid receptor-magnesium interaction and positive allosteric modulation. Biophys. J. 118, 909–921 (2020).
Holst, B., Elling, C. E. & Schwartz, T. W. Metal ion-mediated agonism and agonist enhancement in melanocortin MC1 and MC4 receptors. J. Biol. Chem. 277, 47662–47670 (2002).
Link, R. et al. The constitutive activity of melanocortin-4 receptors in cAMP pathway is allosterically modulated by zinc and copper ions. J. Neurochem. 153, 346–361 (2020).
Yu, J. et al. Determination of the melanocortin-4 receptor structure identifies Ca2+ as a cofactor for ligand binding. Science 368, 428–433 (2020).
Israeli, H. et al. Structure reveals the activation mechanism of the MC4 receptor to initiate satiation signaling. Science 372, 808–814 (2021).
Huang, X.-P., Kenakin, T. P., Gu, S., Shoichet, B. K. & Roth, B. L. Differential roles of extracellular histidine residues of GPR68 for proton-sensing and allosteric modulation by divalent metal ions. Biochemistry 59, 3594–3614 (2020).
Corradi, V. et al. Emerging diversity in lipid–protein interactions. Chem. Rev. 119, 5775–5848 (2019).
Thakur, N. et al. Anionic phospholipids control mechanisms of GPCR-G protein recognition. Nat. Commun. 14, 794 (2023).
Faust, B. et al. Autoantibody mimicry of hormone action at the thyrotropin receptor. Nature 609, 846–853 (2022).
Corey, R. A., Stansfeld, P. J. & Sansom, M. S. P. The energetics of protein–lipid interactions as viewed by molecular simulations. Biochem. Soc. Trans. 48, 25–37 (2020).
Song, W. et al. PyLipID: a python package for analysis of protein–lipid interactions from molecular dynamics simulations. J. Chem. Theory Comput. 18, 1188–1201 (2022).
Sejdiu, B. I. & Tieleman, D. P. ProLint: a web-based framework for the automated data analysis and visualization of lipid–protein interactions. Nucleic Acids Res. 49, W544–W550 (2021).
Smith, P. & Lorenz, C. D. LiPyphilic: a python toolkit for the analysis of lipid membrane simulations. J. Chem. Theory Comput. 17, 5907–5919 (2021).
Cao, R. et al. Role of extracellular loops and membrane lipids for ligand recognition in the neuronal adenosine receptor type 2A: an enhanced sampling simulation study. Molecules 23, 2616 (2018).
Ansell, T. B. et al. LipIDens: simulation assisted interpretation of lipid densities in cryo-EM structures of membrane proteins. Nat. Commun. 14, 7774 (2023).
Levental, I. & Lyman, E. Regulation of membrane protein structure and function by their lipid nano-environment. Nat. Rev. Mol. Cell Biol. 24, 107–122 (2023).
Song, W., Yen, H.-Y., Robinson, C. V. & Sansom, M. S. P. State-dependent lipid interactions with the A2a receptor revealed by MD simulations using in vivo-mimetic membranes. Structure 27, 392–403.e3 (2019).
Ansell, T. B., Song, W. & Sansom, M. S. P. The glycosphingolipid GM3 modulates conformational dynamics of the glucagon receptor. Biophys. J. 119, 300–313 (2020).
Yuan, S. et al. The molecular mechanism of P2Y1 receptor activation. Angew. Chem. Int. Ed. 128, 10487–10491 (2016).
Cao, R., Rossetti, G., Bauer, A. & CarIoni, P. Binding of the antagonist caffeine to the human adenosine receptor hA2AR in nearly physiological conditions. PLoS ONE 10, e0126833 (2015).
Damian, M. et al. Allosteric modulation of ghrelin receptor signaling by lipids. Nat. Commun. 12, 3938 (2021).
Yen, H.-Y. et al. PtdIns(4,5)P2 stabilizes active states of GPCRs and enhances selectivity of G-protein coupling. Nature 559, 423–427 (2018).
Thakur, N. Membrane mimetic-dependence of GPCR energy landscapes. Structure 32, 523–535.e5 (2024).
McGraw, C., Koretz, K. S., Oseid, D., Lyman, E. & Robinson, A. S. Cholesterol dependent activity of the adenosine A2A receptor is modulated via the cholesterol consensus motif. Molecules 27, 3529 (2022).
Lyman, E. et al. A role for a specific cholesterol interaction in stabilizing the apo configuration of the human A2A adenosine receptor. Structure 17, 1660–1668 (2009).
Ray, A. P., Thakur, N., Pour, N. G. & Eddy, M. T. Dual mechanisms of cholesterol-GPCR interactions that depend on membrane phospholipid composition. Structure 31, 836–847.e6 (2023).
Huang, S. K. et al. Allosteric modulation of the adenosine A2A receptor by cholesterol. eLife 11, e73901 (2022).
Kinnebrew, M. et al. Patched 1 regulates Smoothened by controlling sterol binding to its extracellular cysteine-rich domain. Sci. Adv. 8, eabm5563 (2022).
Acknowledgements
This work has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (“CoMMBi” ERC grant agreement No.101001784), and it was supported by a grant from the Swiss National Supercomputing Centre (CSCS) under project ID u8. P.W.H. acknowledges funding by the German Research Foundation (DFG) through CRC1423, project number 421152132, subproject C01 and Z04. M.T.E. acknowledges funding by National Institutes of Health (grant no. R35GM138291). C.G.T. acknowledges core funding from the Medical Research Council [MRC U105197215]. All the authors express their gratitude to the Centre Européen de Calcul Atomique et Moléculaire, the Swiss National Science Foundation (grant No. IZSEZ0_213357), CSCS, Sintetica SA and Novartis Pharma Schweiz AG for their generous support in organizing the 2022 workshop titled Understanding the Function of G Protein-Coupled Receptors through Atomistic and Multiscale Simulations (https://www.cecam.org/workshop-details/understanding-function-of-g-protein-coupled-receptors-by-atomistic-and-multiscale-simulations-39), which inspired the writing of this article. For the purpose of open access, the MRC Laboratory of Molecular Biology has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising.
Author information
Authors and Affiliations
Contributions
V.L. conceptualized the article. P. C. and V. L. researched data for the article and wrote the original draft. All authors reviewed and edited the article.
Corresponding author
Ethics declarations
Competing interests
S.Y. is cofounder of AlphaMol Science Ltd. C.G.T. is a shareholder, consultant and member of the Scientific Advisory Board of Sosei Heptares. The remaining authors declare no competing interests.
Peer review
Peer review information
Nature Reviews Drug Discovery thanks Ryan Strachan and the other, anonymous, reviewers for their contribution to the peer review of this work.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary information
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Conflitti, P., Lyman, E., Sansom, M.S.P. et al. Functional dynamics of G protein-coupled receptors reveal new routes for drug discovery. Nat Rev Drug Discov 24, 251–275 (2025). https://doi.org/10.1038/s41573-024-01083-3
Accepted:
Published:
Issue date:
DOI: https://doi.org/10.1038/s41573-024-01083-3
This article is cited by
-
G protein-coupled receptors: pivotal hubs in gastric cancer malignancy—from multidimensional crosstalk to precision therapeutics
Journal of Translational Medicine (2025)
-
GPCR drug discovery: new agents, targets and indications
Nature Reviews Drug Discovery (2025)
-
Unraveling allosteric signaling of G protein-coupled receptors (GPCRs) by single-molecule fluorescence
Biophysical Reviews (2025)
