How Ligands Illuminate GPCR Molecular Pharmacology Daniel Wacker, Raymond C. Stevens, Bryan L. Roth  Cell  Volume 170, Issue 3, Pages 414-427 (July 2017) DOI: 10.1016/j.cell.2017.07.009 Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 1 Different Ligand-Stabilized GPCR Conformations Cause Binding and Activation of Distinct Signal Transducers, including G Proteins and Arrestins Left: crystal structure of β2AR (light blue cartoon) coupled to Gαs (blue), Gβ (orange), Gγ (green) heterotrimer (PDB: 3SN6 [Rasmussen et al., 2011b]) illustrates G protein-mediated signaling. Upon heterotrimer activation, subunits dissociate, and Gα modulates second messenger production such as cAMP production through Gαs-mediated activation of adenylyl cyclase. Gβγ modulates separate Gα-independent downstream signaling networks such as ion channels, phospholipases, and receptor kinases. Right: crystal structure of rhodopsin (light blue cartoon) coupled to β-arrestin (salmon) (PDB: 4ZWJ [Kang et al., 2015]) illustrates arrestin-mediated effects such as receptor internalization or activation of kinase signaling networks. Cell 2017 170, 414-427DOI: (10.1016/j.cell.2017.07.009) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 2 GPCRome-wide Targets of Approved and Marketed Medications and How Ligands Uncover Unknown GPCR Physiology toward Potential Therapeutic Applications (A) Sphere size corresponds to number of approved drugs for highlighted therapeutic GPCR target with antagonists, agonists, and negative allosteric modulators shown in red, green, and blue, respectively. Phylogenetic tree of the GPCRome highlights the small fraction of GPCRs that are currently targeted by approved medications. (B) Representative examples and their structures are shown for compounds used to identify previously unknown pharmacology at various receptors. Phylogenetic tree of the GPCRome highlights the diversity of GPCRs identified as off-targets. Cell 2017 170, 414-427DOI: (10.1016/j.cell.2017.07.009) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 3 Molecular and Structural Pharmacology Extend the Ternary Complex Model for Quantitative Description of Drug Action at GPCRs Several ligand-bound inactive receptor states (R′L, R″L, etc.) and ligand-bound active receptor states (R∗1L, R∗2L, etc.), as well as ternary complex structures of ligand- and effector-bound active receptor states (R∗GL, R∗AL) (PDB: 3SN6 [Rasmussen et al., 2011b]; PDB: 4ZWJ [Kang et al., 2015]), have been structurally characterized by X-ray crystallography. Distinct conformational characteristics such as the sodium-binding site of the A2AAR (PDB: 4EIY [Liu et al., 2012b]), the ionic lock of a nanobody stabilized β2AR (PDB: 5JQH [Staus et al., 2016]), the PIF motif of the 5-HT2B receptor (PDB: 4IB4 [Wacker et al., 2013], PDB: 3NY8 [Wacker et al., 2010]), and the NPxxY motif of a nanobody-bound β2AR (PDB: 3NY8 [Wacker et al., 2010], PDB: 3P0G [Rasmussen et al., 2011a]) highlight diverse GPCR activation states. Cell 2017 170, 414-427DOI: (10.1016/j.cell.2017.07.009) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 4 Crystal Structures of Different GPCR-Ligand Complexes Highlight the Diverse Locations of Ligand-Binding Sites Ligands are shown as stick models with transparent surfaces, and receptors are shown in cartoon representation in light blue. Complexes show retinal-bound RHO, LY2119620-bound CHRM2, sodium-bound ADORA2A, ergotamine-bound HTR2B, CCR2-RA-[R]-bound CCR2, MK-0893-bound GCGR, CP-376395-bound CRHR1, and BPTU-bound P2RY1. Cell 2017 170, 414-427DOI: (10.1016/j.cell.2017.07.009) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 5 Computational Approaches Generate Novel Tool Compounds for GPCRs As shown here, the “pickpocketing” approach identifies GPCRs with potentially related ligand-binding properties according to ligand contact strength informed pocket alignment. Similar ligand-binding properties between the Neuropeptide S receptor (NPS) and the orphan GPCR GPR37L1 identified the NPS receptor ligand SHA68 as a novel ligand to interrogate GPR37L1 function. Data schematized according to Ngo et al. (2017). Cell 2017 170, 414-427DOI: (10.1016/j.cell.2017.07.009) Copyright © 2017 Elsevier Inc. Terms and Conditions

Cell 2017 170, 414-427DOI: (10.1016/j.cell.2017.07.009) Copyright © 2017 Elsevier Inc. Terms and Conditions