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Meireles FATP, Antunes D, Temerozo JR, Bou-Habib DC, Caffarena ER. PACAP key interactions with PAC1, VPAC1, and VPAC2 identified by molecular dynamics simulations. J Biomol Struct Dyn 2024; 42:3128-3144. [PMID: 37216328 DOI: 10.1080/07391102.2023.2213349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 05/01/2023] [Indexed: 05/24/2023]
Abstract
The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) belongs to the glucagon/secretin family. PACAP interacts with the pituitary adenylate cyclase-activating polypeptide receptor type 1 (PAC1) and vasoactive intestinal peptide receptors 1 and 2 (VPAC1 and VPAC2), exhibiting functions in the immune, endocrine, and nervous systems. This peptide is upregulated in numerous instances of brain injury, acting as a neuroprotective agent. It can also suppress HIV-1 and SARS-CoV-2 viral replication in vitro. This work aimed to identify, in each peptide-receptor system, the most relevant residues for complex stability and interaction energy communication via Molecular Dynamics (MD), Free Energy calculations, and Protein-energy networks, thus revealing in detail the underlying mechanisms of activation of these receptors. Hydrogen bond formation, interaction energies, and computational alanine scanning between PACAP and its receptors showed that His1, Asp3, Arg12, Arg14, and Lys15 are crucial to the peptide's stability. Furthermore, several PACAP interactions with structurally conserved positions deemed necessary in GPCR B1 activation, including Arg2.60, Lys2.67, and Glu7.42, were significant for the peptide's stability within the receptors. According to the protein-energy network, the connection between Asp3 of PACAP and the receptors' conserved Arg2.60 represents a critical energy communication hub in all complexes. Additionally, the ECDs of the receptors were also found to function as energy communication hubs for PACAP. Although the overall binding mode of PACAP in the three receptors was found to be highly conserved, Arg12 and Tyr13 of PACAP were more prominent in complex with PAC1, while Ser2 of PACAP was with VPAC2. The detailed analyses performed in this work pave the way for using PACAP and its receptors as therapeutic targets.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
| | - Deborah Antunes
- Laboratory of Applied Genomics and Bioinnovations, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
| | - Jairo R Temerozo
- Laboratory on Thymus Research, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation, Rio de Janeiro, Brazil
| | - Dumith Chequer Bou-Habib
- Laboratory on Thymus Research, Oswaldo Cruz Institute/Fiocruz, Rio de Janeiro, Brazil
- National Institute of Science and Technology on Neuroimmunomodulation, Rio de Janeiro, Brazil
| | - Ernesto Raul Caffarena
- Computational Biophysics and Molecular Modeling Group, Scientific Computing Program/Fiocruz, Rio de Janeiro, Brazil
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2
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Hok L, Vianello R. Selective Deuteration Improves the Affinity of Adenosine A 2A Receptor Ligands: A Computational Case Study with Istradefylline and Caffeine. J Chem Inf Model 2023; 63:3138-3149. [PMID: 37155356 DOI: 10.1021/acs.jcim.3c00424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We used a range of computational techniques to assess the effect of selective C-H deuteration on the antagonist istradefylline affinity for the adenosine A2A receptor, which was discussed relative to its structural analogue caffeine, a well-known and likely the most widely used stimulant. The obtained results revealed that smaller caffeine shows high receptor flexibility and exchanges between two distinct poses, which agrees with crystallographic data. In contrast, the additional C8-trans-styryl fragment in istradefylline locks the ligand within a uniform binding pose, while contributing to the affinity through the C-H···π and π···π contacts with surface residues, which, together with its much lower hydration prior to binding, enhances the affinity over caffeine. In addition, the aromatic C8-unit shows a higher deuteration sensitivity over the xanthine part, so when both of its methoxy groups are d6-deuterated, the affinity improvement is -0.4 kcal mol-1, which surpasses the overall affinity gain of -0.3 kcal mol-1 in the perdeuterated d9-caffeine. Yet, the latter predicts around 1.7-fold potency increase, being relevant for its pharmaceutical implementations, and also those within the coffee and energy drink production industries. Still, the full potential of our strategy is achieved in polydeuterated d19-istradefylline, whose A2A affinity improves by -0.6 kcal mol-1, signifying a 2.8-fold potency increase that strongly promotes it as a potential synthetic target. This knowledge supports deuterium application in drug design, and while the literature already reports about over 20 deuterated drugs currently in the clinical development, it is easily foreseen that more examples will hit the market in the years to come. With this in mind, we propose that the devised computational methodology, involving the ONIOM division of the QM region for the ligand and the MM region for its environment, with an implicit quantization of nuclear motions relevant for the H/D exchange, allows fast and efficient estimates of the binding isotope effects in any biological system.
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Affiliation(s)
- Lucija Hok
- Laboratory for the Computational Design and Synthesis of Functional Materials, Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Robert Vianello
- Laboratory for the Computational Design and Synthesis of Functional Materials, Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, 10000 Zagreb, Croatia
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3
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Russo AF, Hay DL. CGRP physiology, pharmacology, and therapeutic targets: migraine and beyond. Physiol Rev 2023; 103:1565-1644. [PMID: 36454715 PMCID: PMC9988538 DOI: 10.1152/physrev.00059.2021] [Citation(s) in RCA: 63] [Impact Index Per Article: 63.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 11/23/2022] [Accepted: 11/27/2022] [Indexed: 12/03/2022] Open
Abstract
Calcitonin gene-related peptide (CGRP) is a neuropeptide with diverse physiological functions. Its two isoforms (α and β) are widely expressed throughout the body in sensory neurons as well as in other cell types, such as motor neurons and neuroendocrine cells. CGRP acts via at least two G protein-coupled receptors that form unusual complexes with receptor activity-modifying proteins. These are the CGRP receptor and the AMY1 receptor; in rodents, additional receptors come into play. Although CGRP is known to produce many effects, the precise molecular identity of the receptor(s) that mediates CGRP effects is seldom clear. Despite the many enigmas still in CGRP biology, therapeutics that target the CGRP axis to treat or prevent migraine are a bench-to-bedside success story. This review provides a contextual background on the regulation and sites of CGRP expression and CGRP receptor pharmacology. The physiological actions of CGRP in the nervous system are discussed, along with updates on CGRP actions in the cardiovascular, pulmonary, gastrointestinal, immune, hematopoietic, and reproductive systems and metabolic effects of CGRP in muscle and adipose tissues. We cover how CGRP in these systems is associated with disease states, most notably migraine. In this context, we discuss how CGRP actions in both the peripheral and central nervous systems provide a basis for therapeutic targeting of CGRP in migraine. Finally, we highlight potentially fertile ground for the development of additional therapeutics and combinatorial strategies that could be designed to modulate CGRP signaling for migraine and other diseases.
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Affiliation(s)
- Andrew F Russo
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa
- Department of Neurology, University of Iowa, Iowa City, Iowa
- Center for the Prevention and Treatment of Visual Loss, Department of Veterans Affairs Health Center, Iowa City, Iowa
| | - Debbie L Hay
- Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, School of Biological Sciences, The University of Auckland, Auckland, New Zealand
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4
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Chang CL, Cai Z, Hsu SYT. Sustained Activation of CLR/RAMP Receptors by Gel-Forming Agonists. Int J Mol Sci 2022; 23:ijms232113408. [PMID: 36362188 PMCID: PMC9655119 DOI: 10.3390/ijms232113408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/30/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022] Open
Abstract
Background: Adrenomedullin (ADM), adrenomedullin 2 (ADM2), and CGRP family peptides are important regulators of vascular vasotone and integrity, neurotransmission, and fetoplacental development. These peptides signal through CLR/RAMP1, 2, and 3 receptors, and protect against endothelial dysfunction in disease models. As such, CLR/RAMP receptor agonists are considered important therapeutic candidates for various diseases. Methods and Results: Based on the screening of a series of palmitoylated chimeric ADM/ADM2 analogs, we demonstrated a combination of lipidation and accommodating motifs at the hinge region of select peptides is important for gaining an enhanced receptor-activation activity and improved stimulatory effects on the proliferation and survival of human lymphatic endothelial cells when compared to wild-type peptides. In addition, by serendipity, we found that select palmitoylated analogs self-assemble to form liquid gels, and subcutaneous administration of an analog gel led to the sustained presence of the peptide in the circulation for >2 days. Consistently, subcutaneous injection of the analog gel significantly reduced the blood pressure in SHR rats and increased vasodilation in the hindlimbs of adult rats for days. Conclusions: Together, these data suggest gel-forming adrenomedullin analogs may represent promising candidates for the treatment of various life-threatening endothelial dysfunction-associated diseases such as treatment-resistant hypertension and preeclampsia, which are in urgent need of an effective drug.
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Affiliation(s)
- Chia Lin Chang
- Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital Linkou Medical Center, Chang Gung University, Kweishan, Taoyuan 20878, Taiwan
| | - Zheqing Cai
- CL Laboratory LLC, Gaithersburg, MD 20878, USA
| | - Sheau Yu Teddy Hsu
- Adepthera LLC, San Jose, CA 95138, USA
- Correspondence: ; Tel.: +1-650-799-3496
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5
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Nicoli A, Dunkel A, Giorgino T, de Graaf C, Di Pizio A. Classification Model for the Second Extracellular Loop of Class A GPCRs. J Chem Inf Model 2022; 62:511-522. [PMID: 35113559 DOI: 10.1021/acs.jcim.1c01056] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The extracellular loop 2 (ECL2) is the longest and the most diverse loop among class A G protein-coupled receptors (GPCRs). It connects the transmembrane (TM) helices 4 and 5 and contains a highly conserved cysteine through which it is bridged with TM3. In this paper, experimental ECL2 structures were analyzed based on their sequences, shapes, and intramolecular contacts. To take into account the flexibility, we incorporated into our analyses information from the molecular dynamics trajectories available on the GPCRmd website. Despite the high sequence variability, shapes of the analyzed structures, defined by the backbone volume overlaps, can be clustered into seven main groups. Conformational differences within the clusters can be then identified by intramolecular interactions with other GPCR structural domains. Overall, our work provides a reorganization of the structural information of the ECL2 of class A GPCR subfamilies, highlighting differences and similarities on sequence and conformation levels.
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Affiliation(s)
- Alessandro Nicoli
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Andreas Dunkel
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
| | - Toni Giorgino
- Biophysics Institute, National Research Council (CNR-IBF), 20133 Milan, Italy
| | - Chris de Graaf
- Sosei Heptares, Steinmetz Building, Granta Park, Great Abington, Cambridge CB21 6DG, U.K
| | - Antonella Di Pizio
- Leibniz Institute for Food Systems Biology at the Technical University of Munich, 85354 Freising, Germany
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6
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Abstract
Molecular dynamics (MD) simulations have become increasingly useful in the modern drug development process. In this review, we give a broad overview of the current application possibilities of MD in drug discovery and pharmaceutical development. Starting from the target validation step of the drug development process, we give several examples of how MD studies can give important insights into the dynamics and function of identified drug targets such as sirtuins, RAS proteins, or intrinsically disordered proteins. The role of MD in antibody design is also reviewed. In the lead discovery and lead optimization phases, MD facilitates the evaluation of the binding energetics and kinetics of the ligand-receptor interactions, therefore guiding the choice of the best candidate molecules for further development. The importance of considering the biological lipid bilayer environment in the MD simulations of membrane proteins is also discussed, using G-protein coupled receptors and ion channels as well as the drug-metabolizing cytochrome P450 enzymes as relevant examples. Lastly, we discuss the emerging role of MD simulations in facilitating the pharmaceutical formulation development of drugs and candidate drugs. Specifically, we look at how MD can be used in studying the crystalline and amorphous solids, the stability of amorphous drug or drug-polymer formulations, and drug solubility. Moreover, since nanoparticle drug formulations are of great interest in the field of drug delivery research, different applications of nano-particle simulations are also briefly summarized using multiple recent studies as examples. In the future, the role of MD simulations in facilitating the drug development process is likely to grow substantially with the increasing computer power and advancements in the development of force fields and enhanced MD methodologies.
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7
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Serafin DS, Harris NR, Nielsen NR, Mackie DI, Caron KM. Dawn of a New RAMPage. Trends Pharmacol Sci 2020; 41:249-265. [PMID: 32115276 PMCID: PMC7236817 DOI: 10.1016/j.tips.2020.01.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 01/24/2020] [Accepted: 01/27/2020] [Indexed: 01/08/2023]
Abstract
Receptor activity-modifying proteins (RAMPs) interact with G-protein-coupled receptors (GPCRs) to modify their functions, imparting significant implications upon their physiological and therapeutic potentials. Resurging interest in identifying RAMP-GPCR interactions has recently been fueled by coevolution studies and orthogonal technological screening platforms. These new studies reveal previously unrecognized RAMP-interacting GPCRs, many of which expand beyond Class B GPCRs. The consequences of these interactions on GPCR function and physiology lays the foundation for new molecular therapeutic targets, as evidenced by the recent success of erenumab. Here, we highlight recent papers that uncovered novel RAMP-GPCR interactions, human RAMP-GPCR disease-causing mutations, and RAMP-related human pathologies, paving the way for a new era of RAMP-targeted drug development.
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Affiliation(s)
- D Stephen Serafin
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Natalie R Harris
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Natalie R Nielsen
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Duncan I Mackie
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Kathleen M Caron
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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8
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Chang CL, Hsu SYT. Development of chimeric and bifunctional antagonists for CLR/RAMP receptors. PLoS One 2019; 14:e0216996. [PMID: 31150417 PMCID: PMC6544337 DOI: 10.1371/journal.pone.0216996] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 05/02/2019] [Indexed: 11/26/2022] Open
Abstract
CGRP, adrenomedullin (ADM), and adrenomedullin 2 (ADM2) family peptides are
important neuropeptides and hormones for the regulation of neurotransmission,
vasotone, cardiovascular morphogenesis, vascular integrity, and feto‒placental
development. These peptides signal through CLR/RAMP1, 2 and 3 receptor
complexes. CLR/RAMP1, or CGRP receptor, antagonists have been developed for the
treatment of migraine headache and osteoarthritis pain; whereas CLR/RAMP2, or
ADM receptor, antagonists are being developed for the treatment of tumor
growth/metastasis. Based on the finding that an acylated chimeric ADM/ADM2
analog potently stimulates CLR/RAMP1 and 2 signaling, we hypothesized that the
binding domain of this analog could have potent inhibitory activity on CLR/RAMP
receptors. Consistent with this hypothesis, we showed that acylated truncated
ADM/ADM2 analogs of 27–31 residues exhibit potent antagonistic activity toward
CLR/RAMP1 and 2. On the other hand, nonacylated analogs have minimal activity.
Further truncation at the junctional region of these chimeric analogs led to the
generation of CLR/RAMP1-selective antagonists. A 17-amino-acid analog
(Antagonist 2–4) showed 100-fold selectivity for CLR/RAMP1 and was >100-fold
more potent than the classic CGRP receptor antagonist CGRP8-37. In addition, we
showed (1) a lysine residue in the Antagonist 2–4 is important for enhancing the
antagonistic activity, (2) an analog consisted of an ADM sequence motif and a
12-amino-acid binding domain of CGRP exhibits potent CLR/RAMP1-inhibitory
activity, and (3) a chimeric analog consisted of a somatostatin analog and an
ADM antagonist exhibits dual activities on somatostatin and CLR/RAMP receptors.
Because the blockage of CLR/RAMP signaling prevents migraine pain and suppresses
tumor growth/metastasis, further studies of these analogs, which presumably have
better access to the tumor microenvironment and nerve endings at the trigeminal
ganglion and synovial joints as compared to antibody-based therapies, may lead
to the development of better anti-CGRP therapy and alternative antiangiogenesis
therapy. Likewise, the use of bifunctional somatostatin-ADM antagonist analogs
could be a promising strategy for the treatment of high-grade neuroendocrine
tumors by targeting an antiangiogenesis agent to the neuroendocrine tumor
microenvironment.
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Affiliation(s)
- Chia Lin Chang
- Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital
Linkou Medical Center, Chang Gung University, Kweishan, Taoyuan,
Taiwan
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9
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Abstract
The canonical CGRP receptor is a complex between calcitonin receptor-like receptor (CLR), a family B G-protein-coupled receptor (GPCR) and receptor activity-modifying protein 1 (RAMP1). A third protein, receptor component protein (RCP) is needed for coupling to Gs. CGRP can interact with other RAMP-receptor complexes, particularly the AMY1 receptor formed between the calcitonin receptor (CTR) and RAMP1. Crystal structures are available for the binding of CGRP27-37 [D31,P34,F35] to the extracellular domain (ECD) of CLR and RAMP1; these show that extreme C-terminal amide of CGRP interacts with W84 of RAMP1 but the rest of the analogue interacts with CLR. Comparison with the crystal structure of a fragment of the allied peptide adrenomedullin bound to the ECD of CLR/RAMP2 confirms the importance of the interaction of the ligand C-terminus and the RAMP in determining pharmacology specificity, although the RAMPs probably also have allosteric actions. A cryo-electron microscope structure of calcitonin bound to the full-length CTR associated with Gs gives important clues as to the structure of the complete receptor and suggests that the N-terminus of CGRP makes contact with His5.40b, high on TM5 of CLR. However, it is currently not known how the RAMPs interact with the TM bundle of any GPCR. Major challenges remain in understanding how the ECD and TM domains work together to determine ligand specificity, and how G-proteins influence this and the role of RCP. It seems likely that allosteric mechanisms are particularly important as are the dynamics of the receptors.
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Affiliation(s)
- John Simms
- School of Life and Health Science, Aston University, Birmingham, UK
- Coventry University, Coventry, UK
| | - Sarah Routledge
- School of Life and Health Science, Aston University, Birmingham, UK
| | - Romez Uddin
- School of Life and Health Science, Aston University, Birmingham, UK
| | - David Poyner
- School of Life and Health Science, Aston University, Birmingham, UK.
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10
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Banerjee AA, Mahale SD. Extracellular loop 3 substitutions K589N and A590S in FSH receptor increase FSH-induced receptor internalization and along with S588T substitution exhibit impaired ERK1/2 phosphorylation. Arch Biochem Biophys 2018; 659:57-65. [DOI: 10.1016/j.abb.2018.09.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 09/11/2018] [Accepted: 09/14/2018] [Indexed: 12/30/2022]
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11
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Liang YL, Khoshouei M, Deganutti G, Glukhova A, Koole C, Peat TS, Radjainia M, Plitzko JM, Baumeister W, Miller LJ, Hay DL, Christopoulos A, Reynolds CA, Wootten D, Sexton PM. Cryo-EM structure of the active, G s-protein complexed, human CGRP receptor. Nature 2018; 561:492-497. [PMID: 30209400 PMCID: PMC6166790 DOI: 10.1038/s41586-018-0535-y] [Citation(s) in RCA: 165] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 06/26/2018] [Indexed: 12/29/2022]
Abstract
Calcitonin gene-related peptide (CGRP) is a widely expressed neuropeptide that has a major role in sensory neurotransmission. The CGRP receptor is a heterodimer of the calcitonin receptor-like receptor (CLR) class B G-protein-coupled receptor and a type 1 transmembrane domain protein, receptor activity-modifying protein 1 (RAMP1). Here we report the structure of the human CGRP receptor in complex with CGRP and the Gs-protein heterotrimer at 3.3 Å global resolution, determined by Volta phase-plate cryo-electron microscopy. The receptor activity-modifying protein transmembrane domain sits at the interface between transmembrane domains 3, 4 and 5 of CLR, and stabilizes CLR extracellular loop 2. RAMP1 makes only limited direct contact with CGRP, consistent with its function in allosteric modulation of CLR. Molecular dynamics simulations indicate that RAMP1 provides stability to the receptor complex, particularly in the positioning of the extracellular domain of CLR. This work provides insights into the control of G-protein-coupled receptor function.
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Affiliation(s)
- Yi-Lynn Liang
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Maryam Khoshouei
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
- Novartis Institutes for Biomedical Research, Novartis Pharma, Basel, Switzerland
| | | | - Alisa Glukhova
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Cassandra Koole
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Thomas S Peat
- CSIRO Biomedical Manufacturing, Melbourne, Victoria, Australia
| | - Mazdak Radjainia
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Thermo Fisher Scientific, Eindhoven, The Netherlands
| | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Wolfgang Baumeister
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Laurence J Miller
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, AZ, USA
| | - Deborah L Hay
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Arthur Christopoulos
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | | | - Denise Wootten
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
- School of Pharmacy, Fudan University, Shanghai, China.
| | - Patrick M Sexton
- Drug Discovery Biology and Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
- School of Pharmacy, Fudan University, Shanghai, China.
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12
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Simms J, Uddin R, Sakmar TP, Gingell JJ, Garelja ML, Hay DL, Brimble MA, Harris PW, Reynolds CA, Poyner DR. Photoaffinity Cross-Linking and Unnatural Amino Acid Mutagenesis Reveal Insights into Calcitonin Gene-Related Peptide Binding to the Calcitonin Receptor-like Receptor/Receptor Activity-Modifying Protein 1 (CLR/RAMP1) Complex. Biochemistry 2018; 57:4915-4922. [PMID: 30004692 DOI: 10.1021/acs.biochem.8b00502] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Calcitonin gene-related peptide (CGRP) binds to the complex of the calcitonin receptor-like receptor (CLR) with receptor activity-modifying protein 1 (RAMP1). How CGRP interacts with the transmembrane domain (including the extracellular loops) of this family B receptor remains unclear. In this study, a photoaffinity cross-linker, p-azido l-phenylalanine (azF), was incorporated into CLR, chiefly in the second extracellular loop (ECL2) using genetic code expansion and unnatural amino acid mutagenesis. The method was optimized to ensure efficient photolysis of azF residues near the transmembrane bundle of the receptor. A CGRP analogue modified with fluorescein at position 15 was used for detection of ultraviolet-induced cross-linking. The methodology was verified by confirming the known contacts of CGRP to the extracellular domain of CLR. Within ECL2, the chief contacts were I284 on the loop itself and L291, at the top of the fifth transmembrane helix (TM5). Minor contacts were noted along the lip of ECL2 between S286 and L290 and also with M223 in TM3 and F349 in TM6. Full length molecular models of the bound receptor complex suggest that CGRP sits at the top of the TM bundle, with Thr6 of the peptide making contacts with L291 and H295. I284 is likely to contact Leu12 and Ala13 of CGRP, and Leu16 of CGRP is at the ECL/extracellular domain boundary of CLR. The reduced potency, Emax, and affinity of [Leu16Ala]-human α CGRP are consistent with this model. Contacts between Thr6 of CGRP and H295 may be particularly important for receptor activation.
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Affiliation(s)
- John Simms
- Aston University , Birmingham B4 7ET , U.K
- Coventry University , Priory Street , Coventry CV1 5FB , U.K
| | | | - Thomas P Sakmar
- The Rockefeller University , 1230 York Avenue , New York , New York 10065 , United States
| | - Joseph J Gingell
- University of Auckland , 3A Symonds Street , Auckland 1010 , New Zealand
| | - Michael L Garelja
- University of Auckland , 3A Symonds Street , Auckland 1010 , New Zealand
| | - Debbie L Hay
- University of Auckland , 3A Symonds Street , Auckland 1010 , New Zealand
| | - Margaret A Brimble
- University of Auckland , 3A Symonds Street , Auckland 1010 , New Zealand
| | - Paul W Harris
- University of Auckland , 3A Symonds Street , Auckland 1010 , New Zealand
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13
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Zhang Q, Zhou M, Zhao L, Jiang H, Yang H. Dynamic States of the Ligand-Free Class A G Protein-Coupled Receptor Extracellular Side. Biochemistry 2018; 57:4767-4775. [PMID: 29999306 DOI: 10.1021/acs.biochem.8b00146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
G protein-coupled receptors (GPCRs) make up the largest family of drug targets. The second extracellular loop (ECL2) and extracellular end of the third transmembrane helix (TM3) are basic structural elements of the GPCR ligand binding site. Currently, the disulfide bond between the two conserved cysteines in the ECL2 and TM3 is considered to be a basic GPCR structural feature. This disulfide bond has a significant effect on receptor dynamics and ligand binding. Here, molecular dynamics simulations and experimental results show that the two cysteines are distant from one another in the highest-population conformational state of ligand-free class A GPCRs and do not form a disulfide bond, indicating that the dynamics of the GPCR extracellular side are different from our conventional understanding. These surprising dynamics should have important effects on the drug binding process. On the basis of the two distinct ligand-free states, we suggest two kinetic processes for binding of ligands to GPCRs. These results challenge our commonly held beliefs regarding both GPCR structural features and ligand binding.
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Affiliation(s)
- Qiansen Zhang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences , East China Normal University , Shanghai 200241 , China
| | - Mang Zhou
- Shanghai Institute of Materia Medica , Chinese Academy of Sciences , Shanghai 201203 , China
| | - Lifen Zhao
- Shanghai Institute of Materia Medica , Chinese Academy of Sciences , Shanghai 201203 , China
| | - Hualiang Jiang
- Shanghai Institute of Materia Medica , Chinese Academy of Sciences , Shanghai 201203 , China
| | - Huaiyu Yang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences , East China Normal University , Shanghai 200241 , China
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14
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Bower RL, Yule L, Rees TA, Deganutti G, Hendrikse ER, Harris PWR, Kowalczyk R, Ridgway Z, Wong AG, Swierkula K, Raleigh DP, Pioszak AA, Brimble MA, Reynolds CA, Walker CS, Hay DL. Molecular Signature for Receptor Engagement in the Metabolic Peptide Hormone Amylin. ACS Pharmacol Transl Sci 2018; 1:32-49. [PMID: 32219203 DOI: 10.1021/acsptsci.8b00002] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Indexed: 11/30/2022]
Abstract
The pancreatic peptide hormone, amylin, plays a critical role in the control of appetite, and synergizes with other key metabolic hormones such as glucagon-like peptide 1 (GLP-1). There is opportunity to develop potent and long-acting analogues of amylin or hybrids between these and GLP-1 mimetics for treating obesity. To achieve this, interrogation of how the 37 amino acid amylin peptide engages with its complex receptor system is required. We synthesized an extensive library of peptides to profile the human amylin sequence, determining the role of its disulfide loop, amidated C-terminus and receptor "capture" and "activation" regions in receptor signaling. We profiled four signaling pathways with different ligands at multiple receptor subtypes, in addition to exploring selectivity determinants between related receptors. Distinct roles for peptide subregions in receptor binding and activation were identified, resulting in peptides with greater activity than the native sequence. Enhanced peptide activity was preserved in the brainstem, the major biological target for amylin. Interpretation of our data using full-length active receptor models supported by molecular dynamics, metadynamics, and supervised molecular dynamics simulations guided the synthesis of a potent dual agonist of GLP-1 and amylin receptors. The data offer new insights into the function of peptide amidation, how allostery drives peptide-receptor interactions, and provide a valuable resource for the development of novel amylin agonists for treating diabetes and obesity.
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Affiliation(s)
- Rebekah L Bower
- School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand
| | - Lauren Yule
- School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand.,School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand.,School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand
| | - Tayla A Rees
- School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand
| | - Giuseppe Deganutti
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, U.K
| | - Erica R Hendrikse
- School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand
| | - Paul W R Harris
- School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand.,School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand.,School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand
| | - Renata Kowalczyk
- School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand.,School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand
| | - Zachary Ridgway
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Amy G Wong
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Katarzyna Swierkula
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, U.K
| | - Daniel P Raleigh
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794-3400, United States.,Department of Structural and Molecular Biology, University College London, London WC1E 6BT, U.K
| | - Augen A Pioszak
- Department of Biochemistry and Molecular Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, United States
| | - Margaret A Brimble
- School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand.,School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand
| | - Christopher A Reynolds
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, U.K
| | - Christopher S Walker
- School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand
| | - Debbie L Hay
- School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand.,School of Biological Sciences, School of Chemical Sciences, and Maurice Wilkins Centre, The University of Auckland, Auckland, 1010, New Zealand
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15
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Extracellular loops 2 and 3 of the calcitonin receptor selectively modify agonist binding and efficacy. Biochem Pharmacol 2018; 150:214-244. [PMID: 29454620 PMCID: PMC5908784 DOI: 10.1016/j.bcp.2018.02.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 02/07/2018] [Indexed: 02/07/2023]
Abstract
Class B peptide hormone GPCRs are targets for the treatment of major chronic disease. Peptide ligands of these receptors display biased agonism and this may provide future therapeutic advantage. Recent active structures of the calcitonin (CT) and glucagon-like peptide-1 (GLP-1) receptors reveal distinct engagement of peptides with extracellular loops (ECLs) 2 and 3, and mutagenesis of the GLP-1R has implicated these loops in dynamics of receptor activation. In the current study, we have mutated ECLs 2 and 3 of the human CT receptor (CTR), to interrogate receptor expression, peptide affinity and efficacy. Integration of these data with insights from the CTR and GLP-1R active structures, revealed marked diversity in mechanisms of peptide engagement and receptor activation between the CTR and GLP-1R. While the CTR ECL2 played a key role in conformational propagation linked to Gs/cAMP signalling this was mechanistically distinct from that of GLP-1R ECL2. Moreover, ECL3 was a hotspot for distinct ligand- and pathway-specific effects, and this has implications for the future design of biased agonists of class B GPCRs.
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16
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Woolley MJ, Simms J, Mobarec JC, Reynolds CA, Poyner DR, Conner AC. Understanding the molecular functions of the second extracellular loop (ECL2) of the calcitonin gene-related peptide (CGRP) receptor using a comprehensive mutagenesis approach. Mol Cell Endocrinol 2017; 454:39-49. [PMID: 28572046 DOI: 10.1016/j.mce.2017.05.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 05/08/2017] [Accepted: 05/28/2017] [Indexed: 01/02/2023]
Abstract
The extracellular loop 2 (ECL2) region is the most conserved of the three ECL domains in family B G protein-coupled receptors (GPCRs) and has a fundamental role in ligand binding and activation across the receptor super-family. ECL2 is fundamental for ligand-induced activation of the calcitonin gene related peptide (CGRP) receptor, a family B GPCR implicated in migraine and heart disease. In this study we apply a comprehensive targeted non-alanine substitution analysis method and molecular modelling to the functionally important residues of ECL2 to reveal key molecular interactions. We identified an interaction network between R274/Y278/D280/W283. These amino acids had the biggest reduction in signalling following alanine substitution analysis and comprise a group of basic, acidic and aromatic residues conserved in the wider calcitonin family of class B GPCRs. This study identifies key and varied constraints at each locus, including diverse biochemical requirements for neighbouring tyrosine residues and a W283H substitution that recovered wild-type (WT) signalling, despite the strictly conserved nature of the central ECL2 tryptophan and the catastrophic effects on signalling of W283A substitution. In contrast, while the distal end of ECL2 requires strict conservation of hydrophobicity or polarity in each position, mutation of these residues never has a large effect. This approach has revealed linked networks of amino acids, consistent with structural models of ECL2 and likely to represent a shared structural framework at an important ligand-receptor interface that is present across the family B GPCRs.
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Affiliation(s)
- Michael J Woolley
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - John Simms
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
| | | | | | - David R Poyner
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
| | - Alex C Conner
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
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17
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Woolley MJ, Simms J, Uddin S, Poyner DR, Conner AC. Relative Antagonism of Mutants of the CGRP Receptor Extracellular Loop 2 Domain (ECL2) Using a Truncated Competitive Antagonist (CGRP 8-37): Evidence for the Dual Involvement of ECL2 in the Two-Domain Binding Model. Biochemistry 2017; 56:3877-3880. [PMID: 28691801 DOI: 10.1021/acs.biochem.7b00077] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The second extracellular loop (ECL2) of the G protein-coupled receptor (GPCR) family is important for ligand interaction and drug discovery. ECL2 of the family B cardioprotective calcitonin gene-related peptide (CGRP) receptor is required for cell signaling. Family B GPCR ligands have two regions; the N-terminus mediates receptor activation, and the remainder confers high-affinity binding. Comparing antagonism of CGRP8-37 at a number of point mutations of ECL2 of the CGRP receptor, we show that the ECL2 potentially facilitates interaction with up to the 18 N-terminal residues of CGRP. This has implications for understanding family B GPCR activation and for drug design at the CGRP receptor.
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Affiliation(s)
- Michael J Woolley
- College of Medical and Dental Sciences, University of Birmingham , Edgbaston, Birmingham B15 2TT, U.K
| | - John Simms
- School of Life and Health Sciences, Aston University , Aston Triangle, Birmingham B4 7ET, U.K
| | - Sifat Uddin
- College of Medical and Dental Sciences, University of Birmingham , Edgbaston, Birmingham B15 2TT, U.K
| | - David R Poyner
- School of Life and Health Sciences, Aston University , Aston Triangle, Birmingham B4 7ET, U.K
| | - Alex C Conner
- College of Medical and Dental Sciences, University of Birmingham , Edgbaston, Birmingham B15 2TT, U.K
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18
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Woolley MJ, Reynolds CA, Simms J, Walker CS, Mobarec JC, Garelja ML, Conner AC, Poyner DR, Hay DL. Receptor activity-modifying protein dependent and independent activation mechanisms in the coupling of calcitonin gene-related peptide and adrenomedullin receptors to Gs. Biochem Pharmacol 2017; 142:96-110. [PMID: 28705698 PMCID: PMC5609567 DOI: 10.1016/j.bcp.2017.07.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 07/06/2017] [Indexed: 12/23/2022]
Abstract
Calcitonin gene-related peptide (CGRP) or adrenomedullin (AM) receptors are heteromers of the calcitonin receptor-like receptor (CLR), a class B G protein-coupled receptor, and one of three receptor activity-modifying proteins (RAMPs). How CGRP and AM activate CLR and how this process is modulated by RAMPs is unclear. We have defined how CGRP and AM induce Gs-coupling in CLR-RAMP heteromers by measuring the effect of targeted mutagenesis in the CLR transmembrane domain on cAMP production, modeling the active state conformations of CGRP and AM receptors in complex with the Gs C-terminus and conducting molecular dynamics simulations in an explicitly hydrated lipidic bilayer. The largest effects on receptor signaling were seen with H295A5.40b, I298A5.43b, L302A5.47b, N305A5.50b, L345A6.49b and E348A6.52b, F349A6.53b and H374A7.47b (class B numbering in superscript). Many of these residues are likely to form part of a group in close proximity to the peptide binding site and link to a network of hydrophilic and hydrophobic residues, which undergo rearrangements to facilitate Gs binding. Residues closer to the extracellular loops displayed more pronounced RAMP or ligand-dependent effects. Mutation of H3747.47b to alanine increased AM potency 100-fold in the CGRP receptor. The molecular dynamics simulation showed that TM5 and TM6 pivoted around TM3. The data suggest that hydrophobic interactions are more important for CLR activation than other class B GPCRs, providing new insights into the mechanisms of activation of this class of receptor. Furthermore the data may aid in the understanding of how RAMPs modulate the signaling of other class B GPCRs.
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Affiliation(s)
- Michael J Woolley
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Christopher A Reynolds
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | - John Simms
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK
| | | | - Juan Carlos Mobarec
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | - Michael L Garelja
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Alex C Conner
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - David R Poyner
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, UK.
| | - Debbie L Hay
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.
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19
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Woolley MJ, Conner AC. Understanding the common themes and diverse roles of the second extracellular loop (ECL2) of the GPCR super-family. Mol Cell Endocrinol 2017; 449:3-11. [PMID: 27899324 DOI: 10.1016/j.mce.2016.11.023] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/02/2016] [Accepted: 11/24/2016] [Indexed: 11/16/2022]
Abstract
The extracellular loops (ECLs) of G protein-coupled receptors (GPCRs) can bind directly to docked orthosteric or allosteric ligands, they can contain transient contact points for ligand entry into the transmembrane (TM) bundle and they can regulate the activation of the receptor signalling pathways. Of the three ECLs, ECL2 is the largest and most structurally diverse reflecting its functional importance. This has been shown through biochemical techniques and has been supported by the many subsequent crystal structures of GPCRs bound to both agonists and antagonists. ECL2 shares common structural features between (and sometimes across) receptor sub-families and can facilitate ligand entry to the TM core or act directly as a surface of the ligand-binding pocket. Structural similarities seem to underpin common binding mechanisms; however, where these exist, variations in primary sequence ensure ligand-binding specificity. This review will compare current understanding of the structural themes and main functional roles of ECL2 in ligand binding, activation and regulation of the major families of GPCRs.
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Affiliation(s)
- Michael J Woolley
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Alex C Conner
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK.
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20
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Wootten D, Reynolds CA, Smith KJ, Mobarec JC, Furness SGB, Miller LJ, Christopoulos A, Sexton PM. Key interactions by conserved polar amino acids located at the transmembrane helical boundaries in Class B GPCRs modulate activation, effector specificity and biased signalling in the glucagon-like peptide-1 receptor. Biochem Pharmacol 2016; 118:68-87. [PMID: 27569426 PMCID: PMC5063953 DOI: 10.1016/j.bcp.2016.08.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/15/2016] [Indexed: 11/28/2022]
Abstract
Class B GPCRs can activate multiple signalling effectors with the potential to exhibit biased agonism in response to ligand stimulation. Previously, we highlighted key TM domain polar amino acids that were crucial for the function of the GLP-1 receptor, a key therapeutic target for diabetes and obesity. Using a combination of mutagenesis, pharmacological characterisation, mathematical and computational molecular modelling, this study identifies additional highly conserved polar residues located towards the TM helical boundaries of Class B GPCRs that are important for GLP-1 receptor stability and/or controlling signalling specificity and biased agonism. This includes (i) three positively charged residues (R3.30227, K4.64288, R5.40310) located at the extracellular boundaries of TMs 3, 4 and 5 that are predicted in molecular models to stabilise extracellular loop 2, a crucial domain for ligand affinity and receptor activation; (ii) a predicted hydrogen bond network between residues located in TMs 2 (R2.46176), 6 (R6.37348) and 7 (N7.61406 and E7.63408) at the cytoplasmic face of the receptor that is important for stabilising the inactive receptor and directing signalling specificity, (iii) residues at the bottom of TM 5 (R5.56326) and TM6 (K6.35346 and K6.40351) that are crucial for receptor activation and downstream signalling; (iv) residues predicted to be involved in stabilisation of TM4 (N2.52182 and Y3.52250) that also influence cell signalling. Collectively, this work expands our understanding of peptide-mediated signalling by the GLP-1 receptor.
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Affiliation(s)
- Denise Wootten
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria 3052, Australia.
| | - Christopher A Reynolds
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | - Kevin J Smith
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | - Juan C Mobarec
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | - Sebastian G B Furness
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria 3052, Australia
| | - Laurence J Miller
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, AZ 85259, USA
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria 3052, Australia
| | - Patrick M Sexton
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences and Department of Pharmacology, Monash University, Parkville, Victoria 3052, Australia.
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21
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Watkins HA, Chakravarthy M, Abhayawardana RS, Gingell JJ, Garelja M, Pardamwar M, McElhinney JMWR, Lathbridge A, Constantine A, Harris PWR, Yuen TY, Brimble MA, Barwell J, Poyner DR, Woolley MJ, Conner AC, Pioszak AA, Reynolds CA, Hay DL. Receptor Activity-modifying Proteins 2 and 3 Generate Adrenomedullin Receptor Subtypes with Distinct Molecular Properties. J Biol Chem 2016; 291:11657-75. [PMID: 27013657 PMCID: PMC4882435 DOI: 10.1074/jbc.m115.688218] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 03/20/2016] [Indexed: 01/28/2023] Open
Abstract
Adrenomedullin (AM) is a peptide hormone with numerous effects in the vascular systems. AM signals through the AM1 and AM2 receptors formed by the obligate heterodimerization of a G protein-coupled receptor, the calcitonin receptor-like receptor (CLR), and receptor activity-modifying proteins 2 and 3 (RAMP2 and RAMP3), respectively. These different CLR-RAMP interactions yield discrete receptor pharmacology and physiological effects. The effective design of therapeutics that target the individual AM receptors is dependent on understanding the molecular details of the effects of RAMPs on CLR. To understand the role of RAMP2 and -3 on the activation and conformation of the CLR subunit of AM receptors, we mutated 68 individual amino acids in the juxtamembrane region of CLR, a key region for activation of AM receptors, and determined the effects on cAMP signaling. Sixteen CLR mutations had differential effects between the AM1 and AM2 receptors. Accompanying this, independent molecular modeling of the full-length AM-bound AM1 and AM2 receptors predicted differences in the binding pocket and differences in the electrostatic potential of the two AM receptors. Druggability analysis indicated unique features that could be used to develop selective small molecule ligands for each receptor. The interaction of RAMP2 or RAMP3 with CLR induces conformational variation in the juxtamembrane region, yielding distinct binding pockets, probably via an allosteric mechanism. These subtype-specific differences have implications for the design of therapeutics aimed at specific AM receptors and for understanding the mechanisms by which accessory proteins affect G protein-coupled receptor function.
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Affiliation(s)
- Harriet A Watkins
- From the School of Biological Sciences, the Maurice Wilkins Centre for Molecular Biodiscovery, and
| | | | | | - Joseph J Gingell
- From the School of Biological Sciences, the Maurice Wilkins Centre for Molecular Biodiscovery, and
| | | | - Meenakshi Pardamwar
- the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - James M W R McElhinney
- the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - Alex Lathbridge
- the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - Arran Constantine
- the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - Paul W R Harris
- the Maurice Wilkins Centre for Molecular Biodiscovery, and the School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Tsz-Ying Yuen
- the Maurice Wilkins Centre for Molecular Biodiscovery, and the School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Margaret A Brimble
- the Maurice Wilkins Centre for Molecular Biodiscovery, and the School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand
| | - James Barwell
- the School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, United Kingdom
| | - David R Poyner
- the School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, United Kingdom
| | - Michael J Woolley
- the School of Clinical and Experimental Medicine, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Alex C Conner
- the School of Clinical and Experimental Medicine, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Augen A Pioszak
- the Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Christopher A Reynolds
- the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom,
| | - Debbie L Hay
- From the School of Biological Sciences, the Maurice Wilkins Centre for Molecular Biodiscovery, and
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22
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Abstract
It is now recognized that G protein-coupled receptors (GPCRs), once considered largely independent functional units, have a far more diverse molecular architecture. Receptor activity-modifying proteins (RAMPs) provide an important example of proteins that interact with GPCRs to modify their function. RAMPs are able to act as pharmacological switches and chaperones, and they can regulate signaling and/or trafficking in a receptor-dependent manner. This review covers recent discoveries in the RAMP field and summarizes the known GPCR partners and functions of RAMPs. We also discuss the first peptide-bound structures of RAMP-GPCR complexes, which give insight into the molecular mechanisms that enable RAMPs to alter the pharmacology and signaling of GPCRs.
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Affiliation(s)
- Debbie L Hay
- School of Biological Sciences and Maurice Wilkins Center, University of Auckland, Auckland 1142, New Zealand;
| | - Augen A Pioszak
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104;
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23
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Banerjee AA, Dupakuntla M, Pathak BR, Mahale SD. FSH receptor-specific residues L501 and I505 in extracellular loop 2 are essential for its function. J Mol Endocrinol 2015; 54:193-204. [PMID: 25791375 DOI: 10.1530/jme-14-0275] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/18/2015] [Indexed: 12/11/2022]
Abstract
The extracellular loop 2 (EL2) of FSH receptor (FSHR) plays a pivotal role in various events downstream of FSH stimulation. Because swapping the six FSHR-specific residues in EL2 (chimeric EL2M) with those from LH/choriogonadotropin receptor resulted in impaired internalization of FSH-FSHR complex and low FSH-induced cAMP production, six substitution mutants of EL2 were generated to ascertain the contribution of individual amino acids to the effects shown by chimeric EL2M. Results revealed that L(501)F mainly and I(505)V to a lesser extent contribute to the diminished receptor function in chimeric EL2M. HEK293 cells stably expressing WT and chimeric EL2M FSHR were generated to track the fate of the receptors post FSH induction. The chimeric EL2M FSHR stable clone showed weak internalization and cAMP response similar to transiently transfected cells. Furthermore, reduced FSH-induced ERK phosphorylation was also observed. The interaction of activated chimeric EL2M and L(501)F FSHR with β-arrestins was weak compared with WT FSHR, thus explaining the impaired internalization of chimeric EL2M and corroborating the indispensable role of EL2 in receptor function.
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Affiliation(s)
- Antara A Banerjee
- Division of Structural BiologyNational Institute for Research in Reproductive Health (Indian Council of Medical Research), Jehangir Merwanji Street, Parel, Mumbai 400 012, IndiaNational Institute for Research in Reproductive Health (Indian Council of Medical Research)ICMR Biomedical Informatics Centre, Jehangir Merwanji Street, Parel, Mumbai 400 012, India
| | - Madhavi Dupakuntla
- Division of Structural BiologyNational Institute for Research in Reproductive Health (Indian Council of Medical Research), Jehangir Merwanji Street, Parel, Mumbai 400 012, IndiaNational Institute for Research in Reproductive Health (Indian Council of Medical Research)ICMR Biomedical Informatics Centre, Jehangir Merwanji Street, Parel, Mumbai 400 012, India
| | - Bhakti R Pathak
- Division of Structural BiologyNational Institute for Research in Reproductive Health (Indian Council of Medical Research), Jehangir Merwanji Street, Parel, Mumbai 400 012, IndiaNational Institute for Research in Reproductive Health (Indian Council of Medical Research)ICMR Biomedical Informatics Centre, Jehangir Merwanji Street, Parel, Mumbai 400 012, India
| | - Smita D Mahale
- Division of Structural BiologyNational Institute for Research in Reproductive Health (Indian Council of Medical Research), Jehangir Merwanji Street, Parel, Mumbai 400 012, IndiaNational Institute for Research in Reproductive Health (Indian Council of Medical Research)ICMR Biomedical Informatics Centre, Jehangir Merwanji Street, Parel, Mumbai 400 012, India Division of Structural BiologyNational Institute for Research in Reproductive Health (Indian Council of Medical Research), Jehangir Merwanji Street, Parel, Mumbai 400 012, IndiaNational Institute for Research in Reproductive Health (Indian Council of Medical Research)ICMR Biomedical Informatics Centre, Jehangir Merwanji Street, Parel, Mumbai 400 012, India
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24
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Identification and functional comparison of seven-transmembrane G-protein-coupled BILF1 receptors in recently discovered nonhuman primate lymphocryptoviruses. J Virol 2014; 89:2253-67. [PMID: 25505061 DOI: 10.1128/jvi.02716-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Coevolution of herpesviruses with their respective host has resulted in a delicate balance between virus-encoded immune evasion mechanisms and host antiviral immunity. BILF1 encoded by human Epstein-Barr virus (EBV) is a 7-transmembrane (7TM) G-protein-coupled receptor (GPCR) with multiple immunomodulatory functions, including attenuation of PKR phosphorylation, activation of G-protein signaling, and downregulation of major histocompatibility complex (MHC) class I surface expression. In this study, we explored the evolutionary and functional relationships between BILF1 receptor family members from EBV and 12 previously uncharacterized nonhuman primate (NHP) lymphocryptoviruses (LCVs). Phylogenetic analysis defined 3 BILF1 clades, corresponding to LCVs of New World monkeys (clade A) or Old World monkeys and great apes (clades B and C). Common functional properties were suggested by a high degree of sequence conservation in functionally important regions of the BILF1 molecules. A subset of BILF1 receptors from EBV and LCVs from NHPs (chimpanzee, orangutan, marmoset, and siamang) were selected for multifunctional analysis. All receptors exhibited constitutive signaling activity via G protein Gαi and induced activation of the NF-κB transcription factor. In contrast, only 3 of 5 were able to activate NFAT (nuclear factor of activated T cells); chimpanzee and orangutan BILF1 molecules were unable to activate NFAT. Similarly, although all receptors were internalized, BILF1 from the chimpanzee and orangutan displayed an altered cellular localization pattern with predominant cell surface expression. This study shows how biochemical characterization of functionally important orthologous viral proteins can be used to complement phylogenetic analysis to provide further insight into diverse microbial evolutionary relationships and immune evasion function. IMPORTANCE Epstein-Barr virus (EBV), known as an oncovirus, is the only human herpesvirus in the genus Lymphocryptovirus (LCV). EBV uses multiple strategies to hijack infected host cells, establish persistent infection in B cells, and evade antiviral immune responses. As part of EBV's immune evasion strategy, the virus encodes a multifunctional 7-transmembrane (7TM) G-protein-coupled receptor (GPCR), EBV BILF1. In addition to multiple immune evasion-associated functions, EBV BILF1 has transforming properties, which are linked to its high constitutive activity. We identified BILF1 receptor orthologues in 12 previously uncharacterized LCVs from nonhuman primates (NHPs) of Old and New World origin. As 7TM receptors are excellent drug targets, our unique insight into the molecular mechanism of action of the BILF1 family and into the evolution of primate LCVs may enable validation of EBV BILF1 as a drug target for EBV-mediated diseases, as well as facilitating the design of drugs targeting EBV BILF1.
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Hay DL, Harris PWR, Kowalczyk R, Brimble MA, Rathbone DL, Barwell J, Conner AC, Poyner DR. Structure-activity relationships of the N-terminus of calcitonin gene-related peptide: key roles of alanine-5 and threonine-6 in receptor activation. Br J Pharmacol 2014; 171:415-26. [PMID: 24125506 PMCID: PMC3904261 DOI: 10.1111/bph.12464] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 09/10/2013] [Accepted: 10/07/2013] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND AND PURPOSE The N-terminus of calcitonin gene-related peptide (CGRP) is important for receptor activation, especially the disulphide-bonded ring (residues 1-7). However, the roles of individual amino acids within this region have not been examined and so the molecular determinants of agonism are unknown. This study has examined the role of residues 1, 3-6 and 8-9, excluding Cys-2 and Cys-7. EXPERIMENTAL APPROACH CGRP derivatives were substituted with either cysteine or alanine; further residues were introduced at position 6. Their affinity was measured by radioligand binding and their efficacy by measuring cAMP production in SK-N-MC cells and β-arrestin 2 translocation in CHO-K1 cells at the CGRP receptor. KEY RESULTS Substitution of Ala-5 by cysteine reduced affinity 270-fold and reduced efficacy for production of cAMP in SK-N-MCs. Potency at β-arrestin translocation was reduced by ninefold. Substitution of Thr-6 by cysteine destroyed all measurable efficacy of both cAMP and β-arrestin responses; substitution with either alanine or serine impaired potency. Substitutions at positions 1, 4, 8 and 9 resulted in approximately 10-fold reductions in potency at both responses. Similar observations were made at a second CGRP-activated receptor, the AMY(1(a)) receptor. CONCLUSIONS AND IMPLICATIONS Ala-5 and Thr-6 are key determinants of agonist activity for CGRP. Ala-5 is also very important for receptor binding. Residues outside of the 1-7 ring also contribute to agonist activity.
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Affiliation(s)
- Debbie L Hay
- School of Biological Sciences and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
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Taddese B, Upton GJ, Bailey GR, Jordan SR, Abdulla NY, Reeves PJ, Reynolds CA. Do plants contain g protein-coupled receptors? PLANT PHYSIOLOGY 2014; 164:287-307. [PMID: 24246381 PMCID: PMC3875809 DOI: 10.1104/pp.113.228874] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 11/16/2013] [Indexed: 05/05/2023]
Abstract
Whether G protein-coupled receptors (GPCRs) exist in plants is a fundamental biological question. Interest in deorphanizing new GPCRs arises because of their importance in signaling. Within plants, this is controversial, as genome analysis has identified 56 putative GPCRs, including G protein-coupled receptor1 (GCR1), which is reportedly a remote homolog to class A, B, and E GPCRs. Of these, GCR2 is not a GPCR; more recently, it has been proposed that none are, not even GCR1. We have addressed this disparity between genome analysis and biological evidence through a structural bioinformatics study, involving fold recognition methods, from which only GCR1 emerges as a strong candidate. To further probe GCR1, we have developed a novel helix-alignment method, which has been benchmarked against the class A-class B-class F GPCR alignments. In addition, we have presented a mutually consistent set of alignments of GCR1 homologs to class A, class B, and class F GPCRs and shown that GCR1 is closer to class A and/or class B GPCRs than class A, class B, or class F GPCRs are to each other. To further probe GCR1, we have aligned transmembrane helix 3 of GCR1 to each of the six GPCR classes. Variability comparisons provide additional evidence that GCR1 homologs have the GPCR fold. From the alignments and a GCR1 comparative model, we have identified motifs that are common to GCR1, class A, B, and E GPCRs. We discuss the possibilities that emerge from this controversial evidence that GCR1 has a GPCR fold.
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Affiliation(s)
| | - Graham J.G. Upton
- School of Biological Sciences (B.T., G.R.B., S.R.D.J., N.Y.A., P.J.R., C.A.R.) and Department of Mathematical Sciences (G.J.G.U.), University of Essex, Colchester, CO4 3SQ United Kingdom
| | - Gregory R. Bailey
- School of Biological Sciences (B.T., G.R.B., S.R.D.J., N.Y.A., P.J.R., C.A.R.) and Department of Mathematical Sciences (G.J.G.U.), University of Essex, Colchester, CO4 3SQ United Kingdom
| | - Siân R.D. Jordan
- School of Biological Sciences (B.T., G.R.B., S.R.D.J., N.Y.A., P.J.R., C.A.R.) and Department of Mathematical Sciences (G.J.G.U.), University of Essex, Colchester, CO4 3SQ United Kingdom
| | - Nuradin Y. Abdulla
- School of Biological Sciences (B.T., G.R.B., S.R.D.J., N.Y.A., P.J.R., C.A.R.) and Department of Mathematical Sciences (G.J.G.U.), University of Essex, Colchester, CO4 3SQ United Kingdom
| | - Philip J. Reeves
- School of Biological Sciences (B.T., G.R.B., S.R.D.J., N.Y.A., P.J.R., C.A.R.) and Department of Mathematical Sciences (G.J.G.U.), University of Essex, Colchester, CO4 3SQ United Kingdom
| | - Christopher A. Reynolds
- School of Biological Sciences (B.T., G.R.B., S.R.D.J., N.Y.A., P.J.R., C.A.R.) and Department of Mathematical Sciences (G.J.G.U.), University of Essex, Colchester, CO4 3SQ United Kingdom
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