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Wu Y, Jensen N, Rossner MJ, Wehr MC. Exploiting Cell-Based Assays to Accelerate Drug Development for G Protein-Coupled Receptors. Int J Mol Sci 2024; 25:5474. [PMID: 38791511 PMCID: PMC11121687 DOI: 10.3390/ijms25105474] [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: 04/22/2024] [Revised: 05/10/2024] [Accepted: 05/13/2024] [Indexed: 05/26/2024] Open
Abstract
G protein-coupled receptors (GPCRs) are relevant targets for health and disease as they regulate various aspects of metabolism, proliferation, differentiation, and immune pathways. They are implicated in several disease areas, including cancer, diabetes, cardiovascular diseases, and mental disorders. It is worth noting that about a third of all marketed drugs target GPCRs, making them prime pharmacological targets for drug discovery. Numerous functional assays have been developed to assess GPCR activity and GPCR signaling in living cells. Here, we review the current literature of genetically encoded cell-based assays to measure GPCR activation and downstream signaling at different hierarchical levels of signaling, from the receptor to transcription, via transducers, effectors, and second messengers. Singleplex assay formats provide one data point per experimental condition. Typical examples are bioluminescence resonance energy transfer (BRET) assays and protease cleavage assays (e.g., Tango or split TEV). By contrast, multiplex assay formats allow for the parallel measurement of multiple receptors and pathways and typically use molecular barcodes as transcriptional reporters in barcoded assays. This enables the efficient identification of desired on-target and on-pathway effects as well as detrimental off-target and off-pathway effects. Multiplex assays are anticipated to accelerate drug discovery for GPCRs as they provide a comprehensive and broad identification of compound effects.
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Affiliation(s)
- Yuxin Wu
- Research Group Cell Signalling, Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, Nussbaumstr. 7, 80336 Munich, Germany
- Systasy Bioscience GmbH, Balanstr. 6, 81669 Munich, Germany
| | - Niels Jensen
- Systasy Bioscience GmbH, Balanstr. 6, 81669 Munich, Germany
- Section of Molecular Neurobiology, Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, Nussbaumstr. 7, 80336 Munich, Germany
| | - Moritz J. Rossner
- Systasy Bioscience GmbH, Balanstr. 6, 81669 Munich, Germany
- Section of Molecular Neurobiology, Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, Nussbaumstr. 7, 80336 Munich, Germany
| | - Michael C. Wehr
- Research Group Cell Signalling, Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, Nussbaumstr. 7, 80336 Munich, Germany
- Systasy Bioscience GmbH, Balanstr. 6, 81669 Munich, Germany
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2
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Pottie E, Suresh RR, Jacobson KA, Stove CP. Assay-Dependent Inverse Agonism at the A 3 Adenosine Receptor: When Neutral Is Not Neutral. ACS Pharmacol Transl Sci 2023; 6:1266-1274. [PMID: 37705594 PMCID: PMC10496142 DOI: 10.1021/acsptsci.3c00071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Indexed: 09/15/2023]
Abstract
The A3 adenosine receptor (A3AR) is implicated in a variety of (patho)physiological conditions. While most research has focused on agonists and antagonists, inverse agonism at A3AR has been scarcely studied. Therefore, this study aimed at exploring inverse agonism, using two previously engineered cell lines (hA3ARLgBiT-SmBiTβarr2 and hA3ARLgBiT-SmBiTminiGαi), both employing the NanoBiT technology. The previously established inverse agonist PSB-10 showed a decrease in basal signal in the β-arrestin 2 (βarr2) but not the miniGαi recruitment assay, indicative of inverse agonism in the former assay. Control experiments confirmed the specificity and reversibility of this observation. Evaluation of a set of presumed neutral antagonists (MRS7907, MRS7799, XAC, and MRS1220) revealed that all displayed concentration-dependent signal decreases when tested in the A3AR-βarr2 recruitment assay, yielding EC50 and Emax values for inverse agonism. Conversely, in the miniGαi recruitment assay, no signal decreases were observed. To assess whether this observation was caused by the inability of the ligands to induce inverse agonism in the G protein pathway, or rather by a limitation inherent to the employed A3AR-miniGαi recruitment assay, a GloSensor cAMP assay was performed. The outcome of the latter also suggests inverse agonism by the presumed neutral antagonists in this latter assay. These findings emphasize the importance of prior characterization of ligands in the relevant test system. Moreover, it showed the suitability of the NanoBiT βarr2 recruitment and the GloSensor cAMP assays to capture inverse agonism at the A3AR, as opposed to the NanoBiT miniGαi recruitment assay.
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Affiliation(s)
- Eline Pottie
- Laboratory
of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical
Sciences, Ghent University, Campus Heymans, Ottergemsesteenweg
460, B-9000 Ghent, Belgium
| | - R. Rama Suresh
- Laboratory
of Bioorganic Chemistry, National Institute
of Diabetes & Digestive & Kidney Diseases, National Institutes
of Health, Bethesda, Maryland 20802, United States
| | - Kenneth A. Jacobson
- Laboratory
of Bioorganic Chemistry, National Institute
of Diabetes & Digestive & Kidney Diseases, National Institutes
of Health, Bethesda, Maryland 20802, United States
| | - Christophe P. Stove
- Laboratory
of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical
Sciences, Ghent University, Campus Heymans, Ottergemsesteenweg
460, B-9000 Ghent, Belgium
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3
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Gao ZG, Auchampach JA, Jacobson KA. Species dependence of A 3 adenosine receptor pharmacology and function. Purinergic Signal 2023; 19:523-550. [PMID: 36538251 PMCID: PMC9763816 DOI: 10.1007/s11302-022-09910-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 11/26/2022] [Indexed: 12/24/2022] Open
Abstract
Efforts to fully understand pharmacological differences between G protein-coupled receptor (GPCR) species homologues are generally not pursued in detail during the drug development process. To date, many GPCRs that have been successfully targeted are relatively well-conserved across species in amino acid sequence and display minimal variability of biological effects. However, the A3 adenosine receptor (AR), an exciting drug target for a multitude of diseases associated with tissue injury, ischemia, and inflammation, displays as little as 70% sequence identity among mammalian species (e.g., rodent vs. primate) commonly used in drug development. Consequently, the pharmacological properties of synthetic A3AR ligands vary widely, not only in binding affinity, selectivity, and signaling efficacy, but to the extent that some function as agonists in some species and antagonists in others. Numerous heterocyclic antagonists that have nM affinity at the human A3AR are inactive or weakly active at the rat and mouse A3ARs. Positive allosteric modulators, including the imidazo [4,5-c]quinolin-4-amine derivative LUF6000, are only active at human and some larger animal species that have been evaluated (rabbit and dog), but not rodents. A3AR agonists evoke systemic degranulation of rodent, but not human mast cells. The rat A3AR undergoes desensitization faster than the human A3AR, but the human homologue can be completely re-sensitized and recycled back to the cell surface. Thus, comprehensive pharmacological evaluation and awareness of potential A3AR species differences are critical in studies to further understand the basic biological functions of this unique AR subtype. Recombinant A3ARs from eight different species have been pharmacologically characterized thus far. In this review, we describe in detail current knowledge of species differences in genetic identity, G protein-coupling, receptor regulation, and both orthosteric and allosteric A3AR pharmacology.
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Affiliation(s)
- Zhan-Guo Gao
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892-0810, USA.
| | - John A Auchampach
- Department of Pharmacology and Toxicology, and the Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, 20892-0810, USA.
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Saecker L, Häberlein H, Franken S. Investigation of adenosine A1 receptor-mediated β-arrestin 2 recruitment using a split-luciferase assay. Front Pharmacol 2023; 14:1172551. [PMID: 37324481 PMCID: PMC10268005 DOI: 10.3389/fphar.2023.1172551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/15/2023] [Indexed: 06/17/2023] Open
Abstract
Background: Adenosine A1 receptor (A1AR) plays a prominent role in neurological and cardiac diseases and inflammatory processes. Its endogenous ligand adenosine is known to be one of the key players in the sleep-wake cycle. Like other G protein-coupled receptors (GPCRs), stimulation of A1AR leads to the recruitment of arrestins in addition to the activation of G proteins. So far, little is known about the role of these proteins in signal transduction and regulation of A1AR compared to the activation of G proteins. In this work, we characterized a live cell assay for A1AR-mediated β-arrestin 2 recruitment. We have applied this assay to a set of different compounds that interact with this receptor. Methods: Based on NanoBit® technology, a protein complementation assay was developed in which the A1AR is coupled to the large part of the nanoluciferase (LgBiT), whereas its small part (SmBiT) is fused to the N-terminus of β-arrestin 2. Stimulation of A1AR results in the recruitment of β-arrestin 2 and subsequent complementation of a functional nanoluciferase. For comparison, corresponding data on the effect of receptor stimulation on intracellular cAMP levels were collected for some data sets using the GloSensor™ assay. Results: The assay gives highly reproducible results with a very good signal-to-noise ratio. Capadenoson, in contrast to adenosine, CPA, or NECA, shows only partial agonism in this assay with respect to the recruitment of β-arrestin 2, whereas it shows full agonism in the case of the inhibitory effect of A1AR on cAMP production. By using a GRK2 inhibitor, it becomes clear that the recruitment is at least partially dependent on the phosphorylation of the receptor by this kinase. Interestingly, this was also the first time that we demonstrate the A1AR-mediated recruitment of β-arrestin 2 by stimulation with a valerian extract. Conclusion: The presented assay is a useful tool for the quantitative study of A1AR-mediated β-arrestin 2 recruitment. It allows data collection for stimulatory, inhibitory, and modulatory substances and is also suitable for more complex substance mixtures such as valerian extract.
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Comparative Study of Elabela and Apelin on Apelin Receptor Activation Through β-Arrestin Recruitment. Mol Biotechnol 2023; 65:394-400. [PMID: 35960440 PMCID: PMC9935735 DOI: 10.1007/s12033-022-00529-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 06/23/2022] [Indexed: 10/15/2022]
Abstract
Apelin receptor (APJ) ligands elabela (ELA) and apelin have divergent distributions and function differently in vitro and in vivo. Whether differences exist in their capacity of recruitment of β-arrestins (ARRBs) to APJ remains unknown. The aim of the current study was to investigate the different effects of ELA and apelin on the interaction between APJ and ARRBs in live cells by NanoBiT®. NanoBiT® system is a new technology for studying protein-protein interaction in real-time in live cells, based on the emission of luminescence when two split components of NanoLuc luciferase, large Bit (LgBit) and small Bit (SmBit), complement each other to form an enzymatically active entity. We tagged the APJ and ARRBs with LgBit or SmBit and then evaluated their interactions in transiently transfected HEK293T cells, and determined the signal strength yielded as a result of the interaction. We also investigated the concentration-dependent response of the APJ-ARRB interaction in response to ELA and apelin. Finally, we assessed the effect of F13A, an APJ antagonist which is structurally very similar to apelin-13, on ELA- and apelin-mediated APJ-ARRB interactions. The NanoLuc® luciferase signal was highest in the pair of APJ-LgBit with SmBit-ARRB1 or SmBit-ARRB2. NanoLuc® luciferase signal increased in a concentration-dependent manner from 0.1 nM to 10 μM in response to ELA or apelin. Interestingly, ELA elicited weaker APJ-ARRB interaction signals than apelin. Pre-treatment with F13A potently reduced the APJ-ARRB interaction in response to both ELA and apelin. Our results demonstrated that both ELA and apelin promoted the interaction of APJ and ARRBs in a concentration-dependent manner, and ELA is less efficacious than apelin in inducing the recruitment of ARRBs to APJ, providing a biased functional aspect of ELA vs. apelin at the receptor signaling level. Additionally, ELA and apelin may share the same binding site(s) or pocket(s) at the APJ level.
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6
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Chimeric GPCRs mimic distinct signaling pathways and modulate microglia responses. Nat Commun 2022; 13:4728. [PMID: 35970889 PMCID: PMC9378622 DOI: 10.1038/s41467-022-32390-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 07/28/2022] [Indexed: 11/30/2022] Open
Abstract
G protein-coupled receptors (GPCRs) regulate processes ranging from immune responses to neuronal signaling. However, ligands for many GPCRs remain unknown, suffer from off-target effects or have poor bioavailability. Additionally, dissecting cell type-specific responses is challenging when the same GPCR is expressed on different cells within a tissue. Here, we overcome these limitations by engineering DREADD-based GPCR chimeras that bind clozapine-N-oxide and mimic a GPCR-of-interest. We show that chimeric DREADD-β2AR triggers responses comparable to β2AR on second messenger and kinase activity, post-translational modifications, and protein-protein interactions. Moreover, we successfully recapitulate β2AR-mediated filopodia formation in microglia, an immune cell capable of driving central nervous system inflammation. When dissecting microglial inflammation, we included two additional DREADD-based chimeras mimicking microglia-enriched GPR65 and GPR109A. DREADD-β2AR and DREADD-GPR65 modulate the inflammatory response with high similarity to endogenous β2AR, while DREADD-GPR109A shows no impact. Our DREADD-based approach allows investigation of cell type-dependent pathways without known endogenous ligands. Understanding the function of GPCRs requires stimulation with their specific ligands. Here, the authors design chemogenetic G-protein coupled receptors that allows for the study of receptors without knowing the immediate ligand, and demonstrate its use for the β2-adrenergic receptor in microglia.
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The P2Y 2 Receptor C-Terminal Tail Modulates but Is Dispensable for β-Arrestin Recruitment. Int J Mol Sci 2022; 23:ijms23073460. [PMID: 35408820 PMCID: PMC8999042 DOI: 10.3390/ijms23073460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 02/05/2023] Open
Abstract
The P2Y2 receptor (P2Y2R) is a G protein-coupled receptor that is activated by extracellular ATP and UTP, to a similar extent. This allows it to play roles in the cell's response to the (increased) release of these nucleotides, e.g., in response to stress situations, including mechanical stress and oxygen deprivation. However, despite its involvement in important (patho)physiological processes, the intracellular signaling induced by the P2Y2R remains incompletely described. Therefore, this study implemented a NanoBiT® functional complementation assay to shed more light on the recruitment of β-arrestins (βarr1 and βarr2) upon receptor activation. More specifically, upon determination of the optimal configuration in this assay system, the effect of different (receptor) residues/regions on βarr recruitment to the receptor in response to ATP or UTP was estimated. To this end, the linker was shortened, the C-terminal tail was truncated, and phosphorylatable residues in the third intracellular loop of the receptor were mutated, in either singly or multiply adapted constructs. The results showed that none of the introduced adaptations entirely abolished the recruitment of either βarr, although EC50 values differed and time-luminescence profiles appeared to be qualitatively altered. The results hint at the C-terminal tail modulating the interaction with βarr, while not being indispensable.
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8
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Liu YL, Guo ZY. The NanoBiT-Based Homogenous Ligand-Receptor Binding Assay. Methods Mol Biol 2022; 2525:139-153. [PMID: 35836065 DOI: 10.1007/978-1-0716-2473-9_10] [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] [Indexed: 06/15/2023]
Abstract
NanoLuc Binary Technology (NanoBiT) was recently developed by Promega, based on a large NanoLuc fragment (LgBiT) and two small complementation tags, the low-affinity SmBiT tag and the high-affinity HiBiT tag. In recent studies, we applied NanoBiT to ligand-binding assays of some G protein-coupled receptors via genetic fusion of a secretory LgBiT (sLgBiT) to the extracellular N-terminus of the receptors and covalent attachment of the low-affinity SmBiT tag to an appropriate position of their peptide ligands. The NanoBiT-based homogenous ligand-receptor binding assay is convenient for use and suitable for both the wild-type and mutant receptors, representing a novel tool for interaction mechanism studies of these receptors with their ligands. In the present chapter, we provide detailed protocols for setting up the NanoBiT-based homogenous binding assay using growth hormone secretagogue receptor type 1a (GHSR1a) and its endogenous agonist and antagonist as a representative model system.
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Affiliation(s)
- Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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9
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Kotulová J, Hajdúch M, Džubák P. Current Adenosinergic Therapies: What Do Cancer Cells Stand to Gain and Lose? Int J Mol Sci 2021; 22:12569. [PMID: 34830449 PMCID: PMC8617980 DOI: 10.3390/ijms222212569] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/18/2021] [Accepted: 11/18/2021] [Indexed: 12/12/2022] Open
Abstract
A key objective in immuno-oncology is to reactivate the dormant immune system and increase tumour immunogenicity. Adenosine is an omnipresent purine that is formed in response to stress stimuli in order to restore physiological balance, mainly via anti-inflammatory, tissue-protective, and anti-nociceptive mechanisms. Adenosine overproduction occurs in all stages of tumorigenesis, from the initial inflammation/local tissue damage to the precancerous niche and the developed tumour, making the adenosinergic pathway an attractive but challenging therapeutic target. Many current efforts in immuno-oncology are focused on restoring immunosurveillance, largely by blocking adenosine-producing enzymes in the tumour microenvironment (TME) and adenosine receptors on immune cells either alone or combined with chemotherapy and/or immunotherapy. However, the effects of adenosinergic immunotherapy are not restricted to immune cells; other cells in the TME including cancer and stromal cells are also affected. Here we summarise recent advancements in the understanding of the tumour adenosinergic system and highlight the impact of current and prospective immunomodulatory therapies on other cell types within the TME, focusing on adenosine receptors in tumour cells. In addition, we evaluate the structure- and context-related limitations of targeting this pathway and highlight avenues that could possibly be exploited in future adenosinergic therapies.
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Affiliation(s)
| | | | - Petr Džubák
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, 779 00 Olomouc, Czech Republic; (J.K.); (M.H.)
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10
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EndoBind detects endogenous protein-protein interactions in real time. Commun Biol 2021; 4:1085. [PMID: 34526658 PMCID: PMC8443649 DOI: 10.1038/s42003-021-02600-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 08/24/2021] [Indexed: 11/13/2022] Open
Abstract
We present two high-throughput compatible methods to detect the interaction of ectopically expressed (RT-Bind) or endogenously tagged (EndoBind) proteins of interest. Both approaches provide temporal evaluation of dimer formation over an extended duration. Using examples of the Nrf2-KEAP1 and the CRAF-KRAS-G12V interaction, we demonstrate that our method allows for the detection of signal for more than 2 days after substrate addition, allowing for continuous monitoring of endogenous protein-protein interactions in real time. Bill et al describe two high-throughput methods to detect protein-protein interactions in cells in real-time using the split-NanoLuciferase-complementation system. They demonstrate the methods can detect exogenously (RT-bind) or endogenously (EndoBind) expressed proteins, respectively.
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Déri S, Borbás J, Hartai T, Hategan L, Csányi B, Visnyovszki Á, Madácsy T, Maléth J, Hegedűs Z, Nagy I, Arora R, Labro AJ, Környei L, Varró A, Sepp R, Ördög B. Impaired cytoplasmic domain interactions cause co-assembly defect and loss of function in the p.Glu293Lys KNCJ2 variant isolated from an Andersen-Tawil syndrome patient. Cardiovasc Res 2021; 117:1923-1934. [PMID: 32810216 DOI: 10.1093/cvr/cvaa249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/16/2020] [Accepted: 08/12/2020] [Indexed: 02/07/2023] Open
Abstract
AIMS Subunit interactions at the cytoplasmic domain interface (CD-I) have recently been shown to control gating in inward rectifier potassium channels. Here we report the novel KCNJ2 variant p.Glu293Lys that has been found in a patient with Andersen-Tawil syndrome type 1 (ATS1), causing amino acid substitution at the CD-I of the inward rectifier potassium channel subunit Kir2.1. Neither has the role of Glu293 in gating control been investigated nor has a pathogenic variant been described at this position. This study aimed to assess the involvement of Glu293 in CD-I subunit interactions and to establish the pathogenic role of the p.Glu293Lys variant in ATS1. METHODS AND RESULTS The p.Glu293Lys variant produced no current in homomeric form and showed dominant-negative effect over wild-type (WT) subunits. Immunocytochemical labelling showed the p.Glu293Lys subunits to distribute in the subsarcolemmal space. Salt bridge prediction indicated the presence of an intersubunit salt bridge network at the CD-I of Kir2.1, with the involvement of Glu293. Subunit interactions were studied by the NanoLuc® Binary Technology (NanoBiT) split reporter assay. Reporter constructs carrying NanoBiT tags on the intracellular termini produced no bioluminescent signal above background with the p.Glu293Lys variant in homomeric configuration and significantly reduced signals in cells co-expressing WT and p.Glu293Lys subunits simultaneously. Extracellularly presented reporter tags, however, generated comparable bioluminescent signals with heteromeric WT and p.Glu293Lys subunits and with homomeric WT channels. CONCLUSIONS Loss of function and dominant-negative effect confirm the causative role of p.Glu293Lys in ATS1. Co-assembly of Kir2.1 subunits is impaired in homomeric channels consisting of p.Glu293Lys subunits and is partially rescued in heteromeric complexes of WT and p.Glu293Lys Kir2.1 variants. These data point to an important role of Glu293 in mediating subunit assembly, as well as in gating of Kir2.1 channels.
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Affiliation(s)
- Szilvia Déri
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Dóm tér 12, PO Box 427, Szeged 6720, Hungary
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 12, 6720 Szeged, Hungary
| | - János Borbás
- 2nd Department of Internal Medicine and Cardiology Centre, University of Szeged, Semmelweis u. 8, 6725 Szeged, Hungary
| | - Teodóra Hartai
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Dóm tér 12, PO Box 427, Szeged 6720, Hungary
| | - Lidia Hategan
- 2nd Department of Internal Medicine and Cardiology Centre, University of Szeged, Semmelweis u. 8, 6725 Szeged, Hungary
| | - Beáta Csányi
- 2nd Department of Internal Medicine and Cardiology Centre, University of Szeged, Semmelweis u. 8, 6725 Szeged, Hungary
| | - Ádám Visnyovszki
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Dóm tér 12, PO Box 427, Szeged 6720, Hungary
| | - Tamara Madácsy
- 1st Department of Internal Medicine, University of Szeged, Korányi fasor 8-10, 6720 Szeged, Hungary, Hungary
| | - József Maléth
- 1st Department of Internal Medicine, University of Szeged, Korányi fasor 8-10, 6720 Szeged, Hungary, Hungary
| | - Zoltán Hegedűs
- Institute of Biophysics, Biological Research Centre of the Hungarian Academy of Sciences, Temesvári krt. 62, 6726 Szeged, Hungary
- Department of Biochemistry and Medical Chemistry, University of Pécs, Szigeti út 12, 7624 Pécs, Hungary
| | - István Nagy
- Institute of Biochemistry, Biological Research Centre the Hungarian Academy of Sciences, Temesvári krt. 62, 6726 Szeged, Hungary
- Seqomics Biotechnology Ltd, Vállalkozók útja 7, 6782 Mórahalom, Hungary
| | - Rohit Arora
- Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
| | - Alain J Labro
- Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
- Department of Basic Medical Sciences, University of Ghent, C. Heymanslaan 10, 9000 Ghent, Belgium
| | - László Környei
- Gottsegen György National Institute of Cardiology, Haller u. 9, 1096 Budapest, Hungary
| | - András Varró
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Dóm tér 12, PO Box 427, Szeged 6720, Hungary
- Department of Pharmacology and Pharmacotherapy, Interdisciplinary Excellence Centre, University of Szeged, Dóm tér 12, 6720 Szeged, Hungary
- MTA-SZTE Research Group for Cardiovascular Pharmacology, Hungarian Academy of Sciences, Dóm tér 12, 6720 Szeged, Hungary
| | - Róbert Sepp
- 2nd Department of Internal Medicine and Cardiology Centre, University of Szeged, Semmelweis u. 8, 6725 Szeged, Hungary
| | - Balázs Ördög
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Dóm tér 12, PO Box 427, Szeged 6720, Hungary
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12
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McNeill SM, Baltos JA, White PJ, May LT. Biased agonism at adenosine receptors. Cell Signal 2021; 82:109954. [PMID: 33610717 DOI: 10.1016/j.cellsig.2021.109954] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 02/11/2021] [Accepted: 02/13/2021] [Indexed: 01/14/2023]
Abstract
Adenosine modulates many aspects of human physiology and pathophysiology through binding to the adenosine family of G protein-coupled receptors, which are comprised of four subtypes, the A1R, A2AR, A2BR and A3R. Modulation of adenosine receptor function by exogenous agonists, antagonists and allosteric modulators can be beneficial for a number of conditions including cardiovascular disease, Parkinson's disease, and cancer. Unfortunately, many preclinical drug candidates targeting adenosine receptors have failed in clinical trials due to limited efficacy and/or severe on-target undesired effects. To overcome the key barriers typically encountered when transitioning adenosine receptor ligands into the clinic, research efforts have focussed on exploiting the phenomenon of biased agonism. Biased agonism provides the opportunity to develop ligands that favour therapeutic signalling pathways, whilst avoiding signalling associated with on-target undesired effects. Recent studies have begun to define the structure-function relationships that underpin adenosine receptor biased agonism and establish how this phenomenon can be harnessed therapeutically. In this review we describe the recent advancements made towards achieving therapeutically relevant biased agonism at adenosine receptors.
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Affiliation(s)
- Samantha M McNeill
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Jo-Anne Baltos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia; Department of Pharmacology, Monash University, Melbourne, VIC, Australia.
| | - Paul J White
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Lauren T May
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia; Department of Pharmacology, Monash University, Melbourne, VIC, Australia.
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13
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Franco R, Rivas‐Santisteban R, Reyes-Resina I, Navarro G. The Old and New Visions of Biased Agonism Through the Prism of Adenosine Receptor Signaling and Receptor/Receptor and Receptor/Protein Interactions. Front Pharmacol 2021; 11:628601. [PMID: 33584311 PMCID: PMC7878529 DOI: 10.3389/fphar.2020.628601] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 12/21/2020] [Indexed: 12/18/2022] Open
Abstract
Biased signaling is a concept that has arisen in the G protein-coupled receptor (GCPR) research field, and holds promise for the development of new drug development strategies. It consists of different signaling outputs depending on the agonist's chemical structure. Here we review the most accepted mechanisms for explaining biased agonism, namely the induced fit hypothesis and the key/lock hypothesis, but we also consider how bias can be produced by a given agonist. In fact, different signaling outputs may originate at a given receptor when activated by, for instance, the endogenous agonist. We take advantage of results obtained with adenosine receptors to explain how such mechanism of functional selectivity depends on the context, being receptor-receptor interactions (heteromerization) one of the most relevant and most studied mechanisms for mammalian homeostasis. Considering all the possible mechanisms underlying functional selectivity is essential to optimize the selection of biased agonists in the design of drugs targeting GPCRs.
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Affiliation(s)
- Rafael Franco
- Department Biochemistry and Molecular Biomedicine, School of Biology, University of Barcelona, Barcelona, Spain
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos iii, Madrid, Spain
| | - Rafael Rivas‐Santisteban
- Department Biochemistry and Molecular Biomedicine, School of Biology, University of Barcelona, Barcelona, Spain
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos iii, Madrid, Spain
| | - Irene Reyes-Resina
- RG Neuroplasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Gemma Navarro
- Centro de Investigación en Red, Enfermedades Neurodegenerativas (CiberNed), Instituto de Salud Carlos iii, Madrid, Spain
- Department of Biochemistry and Physiology, School of Pharmacy, University of Barcelona, Barcelona, Spain
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14
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Ma X, Leurs R, Vischer HF. NanoLuc-Based Methods to Measure β-Arrestin2 Recruitment to G Protein-Coupled Receptors. Methods Mol Biol 2021; 2268:233-248. [PMID: 34085273 DOI: 10.1007/978-1-0716-1221-7_16] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cytosolic β-arrestins are key regulators of G protein-coupled receptors (GPCRs) by sterically uncoupling G protein activation, facilitating receptor internalization, and/or acting as G protein-independent signaling scaffolds. The current awareness that GPCR ligands may display bias toward G protein signaling or β-arrestin recruitment makes β-arrestin recruitment assays important additions to the drug discovery toolbox. This chapter describes two NanoLuc-based methods to monitor β-arrestin2 recruitment to the human histamine H1 receptor by measuring bioluminescence resonance energy transfer and enzyme-fragment complementation in real-time on living cells with reasonable high throughput. In addition to the detection of agonism, both assay formats can be used to qualitatively evaluate the binding kinetics of antihistamines on the human histamine H1 receptor.
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Affiliation(s)
- Xiaoyuan Ma
- Amsterdam Institute for Molecules, Medicines and Systems, Division of Medicinal Chemistry, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Rob Leurs
- Amsterdam Institute for Molecules, Medicines and Systems, Division of Medicinal Chemistry, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Henry F Vischer
- Amsterdam Institute for Molecules, Medicines and Systems, Division of Medicinal Chemistry, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
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15
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Dijon NC, Nesheva DN, Holliday ND. Luciferase Complementation Approaches to Measure GPCR Signaling Kinetics and Bias. Methods Mol Biol 2021; 2268:249-274. [PMID: 34085274 DOI: 10.1007/978-1-0716-1221-7_17] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
An understanding of the kinetic contributions to G protein-coupled receptor pharmacology and signaling is increasingly important in compound profiling. Nonequilibrium conditions are commonly present in vivo, for example, as the drug competes with dynamic changes in hormone or neurotransmitter concentration for the receptor. Under such conditions individual binding kinetic properties of the ligands can influence duration of action, local ligand concentration, and functional properties such as the degree of insurmountable inhibition. Mapping the kinetic patterns of GPCR signaling events elicited by agonists, rather than a peak response at a single timepoint, is often key to predicting their functional impact. This is also a path to a better understanding of the origins of ligand bias, and whether such ligands demonstrate their effects through selection of distinct GPCR conformations, or via their kinetic properties. Recent developments in complementation approaches, based on a small bright shrimp luciferase Nanoluc, provide a new route to kinetic analysis of GPCR signaling in living cells that is amenable to the throughput required for compound profiling. In the NanoBiT luciferase complementation system, GPCRs and effector proteins are tagged with Nanoluc fragments optimized for their low interacting affinity and stability. The interactions brought about by GPCR recruitment of the effector are reproduced by a rapid and reversible increase in NanoBiT luminescence, in the presence of its substrate furimazine. Here we discuss the methods for optimizing and validating the GPCR NanoBiT assays, and protocols for their application to study endpoint and kinetic aspects of agonist and antagonist pharmacology. We also describe how timecourse families of agonist concentration response curves, derived from a single NanoBiT assay experiment, can be used to evaluate the kinetic components in operational model derived parameters of ligand bias.
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Affiliation(s)
- Nicola C Dijon
- School of Life Sciences, The Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Nottingham, UK
| | - Desislava N Nesheva
- School of Life Sciences, The Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Nottingham, UK
| | - Nicholas D Holliday
- School of Life Sciences, The Medical School, Queen's Medical Centre, University of Nottingham, Nottingham, UK. .,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Nottingham, UK. .,Excellerate Bioscience, Biocity, Nottingham, UK.
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16
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Soave M, Heukers R, Kellam B, Woolard J, Smit MJ, Briddon SJ, Hill SJ. Monitoring Allosteric Interactions with CXCR4 Using NanoBiT Conjugated Nanobodies. Cell Chem Biol 2020; 27:1250-1261.e5. [PMID: 32610042 PMCID: PMC7573392 DOI: 10.1016/j.chembiol.2020.06.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 06/01/2020] [Accepted: 06/12/2020] [Indexed: 01/01/2023]
Abstract
Camelid single-domain antibody fragments (nanobodies) offer the specificity of an antibody in a single 15-kDa immunoglobulin domain. Their small size allows for easy genetic manipulation of the nanobody sequence to incorporate protein tags, facilitating their use as biochemical probes. The nanobody VUN400, which recognizes the second extracellular loop of the human CXCR4 chemokine receptor, was used as a probe to monitor specific CXCR4 conformations. VUN400 was fused via its C terminus to the 11-amino-acid HiBiT tag (VUN400-HiBiT) which complements LgBiT protein, forming a full-length functional NanoLuc luciferase. Here, complemented luminescence was used to detect VUN400-HiBiT binding to CXCR4 receptors expressed in living HEK293 cells. VUN400-HiBiT binding to CXCR4 could be prevented by orthosteric and allosteric ligands, allowing VUN400-HiBiT to be used as a probe to detect allosteric interactions with CXCR4. These data demonstrate that the high specificity offered by extracellular targeted nanobodies can be utilized to probe receptor pharmacology.
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Affiliation(s)
- Mark Soave
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, UK
| | - Raimond Heukers
- Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), VU University of Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, the Netherlands; QVQ Holding B.V., Yalelaan 1, 3584 CL Utrecht, the Netherlands
| | - Barrie Kellam
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, UK; School of Pharmacy, Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, UK
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, UK
| | - Martine J Smit
- Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), VU University of Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, the Netherlands
| | - Stephen J Briddon
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, UK
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, UK.
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17
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White CW, Caspar B, Vanyai HK, Pfleger KDG, Hill SJ. CRISPR-Mediated Protein Tagging with Nanoluciferase to Investigate Native Chemokine Receptor Function and Conformational Changes. Cell Chem Biol 2020; 27:499-510.e7. [PMID: 32053779 PMCID: PMC7242902 DOI: 10.1016/j.chembiol.2020.01.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/02/2020] [Accepted: 01/24/2020] [Indexed: 02/07/2023]
Abstract
G protein-coupled receptors are a major class of membrane receptors that mediate physiological and pathophysiological cellular signaling. Many aspects of receptor activation and signaling can be investigated using genetically encoded luminescent fusion proteins. However, the use of these biosensors in live cell systems requires the exogenous expression of the tagged protein of interest. To maintain the normal cellular context here we use CRISPR/Cas9-mediated homology-directed repair to insert luminescent tags into the endogenous genome. Using NanoLuc and bioluminescence resonance energy transfer we demonstrate fluorescent ligand binding at genome-edited chemokine receptors. We also demonstrate that split-NanoLuc complementation can be used to investigate conformational changes and internalization of CXCR4 and that recruitment of β-arrestin2 to CXCR4 can be monitored when both proteins are natively expressed. These results show that genetically encoded luminescent biosensors can be used to investigate numerous aspects of receptor function at native expression levels.
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Affiliation(s)
- Carl W White
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Queens Medical Centre, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK; Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, WA 6009, Australia; Australian Research Council Centre for Personalised Therapeutics Technologies, Australia.
| | - Birgit Caspar
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Queens Medical Centre, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Hannah K Vanyai
- Epithelial Biology Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Kevin D G Pfleger
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, WA 6009, Australia; Australian Research Council Centre for Personalised Therapeutics Technologies, Australia; Dimerix Limited, Nedlands, WA 6009, Australia
| | - Stephen J Hill
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Queens Medical Centre, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK; Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, WA 6009, Australia.
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18
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Pottie E, Tosh DK, Gao ZG, Jacobson KA, Stove CP. Assessment of biased agonism at the A 3 adenosine receptor using β-arrestin and miniGα i recruitment assays. Biochem Pharmacol 2020; 177:113934. [PMID: 32224136 DOI: 10.1016/j.bcp.2020.113934] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 03/23/2020] [Indexed: 12/12/2022]
Abstract
The A3 adenosine receptor (A3AR) is a G protein-coupled receptor that is involved in a wide variety of physiological and pathological processes, such as cancer. However, the use of compounds pharmacologically targeting this receptor remains limited in clinical practice, despite extensive efforts for compound synthesis. Moreover, the possible occurrence of biased agonism further complicates the interpretation of the functional characteristics of compounds. Hence the need for simple assays, which are comparable in terms of the used cell lines and read-out technique. We previously established a stable β-arrestin 2 (βarr2) bioassay, employing a simple, luminescent read-out via functional complementation of a split nanoluciferase enzyme. Here, we developed a complementary, new bioassay in which coupling of an engineered miniGαi protein to activated A3AR is monitored using a similar approach. Application of both bioassays for the concurrent determination of the potencies and efficacies of a set of 19 N6-substituted adenosine analogues not only allowed for the characterization of structure-activity relationships, but also for the quantification of biased agonism. Although a broad distribution in potency and efficacy values was obtained within the test panel, no significant bias was observed toward either the βarr2 or miniGαi pathway.
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Affiliation(s)
- Eline Pottie
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Campus Heymans, Ottergemsesteenweg 460, B-9000 Ghent, Belgium
| | - Dilip K Tosh
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health, Bethesda, MD 20802, USA
| | - Zhan-Guo Gao
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health, Bethesda, MD 20802, USA
| | - Kenneth A Jacobson
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health, Bethesda, MD 20802, USA
| | - Christophe P Stove
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Campus Heymans, Ottergemsesteenweg 460, B-9000 Ghent, Belgium.
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19
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Pottie E, Cannaert A, Van Uytfanghe K, Stove CP. Setup of a Serotonin 2A Receptor (5-HT2AR) Bioassay: Demonstration of Its Applicability To Functionally Characterize Hallucinogenic New Psychoactive Substances and an Explanation Why 5-HT2AR Bioassays Are Not Suited for Universal Activity-Based Screening of Biofluids for New Psychoactive Substances. Anal Chem 2019; 91:15444-15452. [DOI: 10.1021/acs.analchem.9b03104] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Eline Pottie
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Annelies Cannaert
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Katleen Van Uytfanghe
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
| | - Christophe P. Stove
- Laboratory of Toxicology, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium
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20
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Tan A, Babak MV, Venkatesan G, Lim C, Klotz KN, Herr DR, Cheong SL, Federico S, Spalluto G, Ong WY, Chen YZ, Loo JSE, Pastorin G. Design, Synthesis and Evaluation of New Indolylpyrimidylpiperazines for Gastrointestinal Cancer Therapy. Molecules 2019; 24:E3661. [PMID: 31614517 PMCID: PMC6832257 DOI: 10.3390/molecules24203661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 10/04/2019] [Accepted: 10/08/2019] [Indexed: 11/29/2022] Open
Abstract
Human A3 adenosine receptor hA3AR has been implicated in gastrointestinal cancer, where its cellular expression has been found increased, thus suggesting its potential as a molecular target for novel anticancer compounds. Observation made in our previous work indicated the importance of the carbonyl group of amide in the indolylpyrimidylpiperazine (IPP) for its human A2A adenosine receptor (hA2AAR) subtype binding selectivity over the other AR subtypes. Taking this observation into account, we structurally modified an indolylpyrimidylpiperazine (IPP) scaffold, 1 (a non-selective adenosine receptors' ligand) into a modified IPP (mIPP) scaffold by switching the position of the carbonyl group, resulting in the formation of both ketone and tertiary amine groups in the new scaffold. Results showed that such modification diminished the A2A activity and instead conferred hA3AR agonistic activity. Among the new mIPP derivatives (3-6), compound 4 showed potential as a hA3AR partial agonist, with an Emax of 30% and EC50 of 2.89 ± 0.55 μM. In the cytotoxicity assays, compound 4 also exhibited higher cytotoxicity against both colorectal and liver cancer cells as compared to normal cells. Overall, this new series of compounds provide a promising starting point for further development of potent and selective hA3AR partial agonists for the treatment of gastrointestinal cancers.
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Affiliation(s)
- Aaron Tan
- NUS Graduate School of Integrative Sciences and Engineering, National University of Singapore, Centre for Life Sciences, #05-01, 28 Medical Drive, Singapore 117456, Singapore.
| | - Maria V Babak
- Department of Pharmacy, National University of Singapore, Singapore 119260, Singapore.
| | | | - Clarissa Lim
- Department of Pharmacy, National University of Singapore, Singapore 119260, Singapore.
| | - Karl-Norbert Klotz
- Institut für Pharmakologie und Toxikologie, Universität Würzburg, 97078 Würzburg, Germany.
| | - Deron Raymond Herr
- Department of Pharmacology, National University of Singapore, Singapore 117600, Singapore.
| | - Siew Lee Cheong
- Department of Pharmaceutical Chemistry, School of Pharmacy, International Medical University, 126 Jalan Jalil Perkasa 19, Bukit Jalil, Kuala Lumpur 57000, Malaysia.
| | - Stephanie Federico
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, 34127 Trieste, Italy.
| | - Giampiero Spalluto
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, 34127 Trieste, Italy.
| | - Wei-Yi Ong
- Department of Anatomy, National University of Singapore, Singapore 119260, Singapore.
| | - Yu Zong Chen
- Department of Pharmacy, National University of Singapore, Singapore 119260, Singapore.
| | - Jason Siau Ee Loo
- School of Pharmacy, Faculty of Health and Medical Sciences, Taylor's University, 1, Jalan Taylors, Subang Jaya, Selangor 47500, Malaysia.
| | - Giorgia Pastorin
- NUS Graduate School of Integrative Sciences and Engineering, National University of Singapore, Centre for Life Sciences, #05-01, 28 Medical Drive, Singapore 117456, Singapore.
- Department of Pharmacy, National University of Singapore, Singapore 119260, Singapore.
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21
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Soave M, Kellam B, Woolard J, Briddon SJ, Hill SJ. NanoBiT Complementation to Monitor Agonist-Induced Adenosine A 1 Receptor Internalization. SLAS DISCOVERY 2019; 25:186-194. [PMID: 31583945 PMCID: PMC6974774 DOI: 10.1177/2472555219880475] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Receptor internalization in response to prolonged agonist treatment is an
important regulator of G protein–coupled receptor (GPCR) function. The adenosine
A1 receptor (A1AR) is one of the adenosine receptor
family of GPCRs, and evidence for its agonist-induced internalization is
equivocal. The recently developed NanoBiT technology uses split NanoLuc
Luciferase to monitor changes in protein interactions. We have modified the
human A1AR on the N-terminus with the small high-affinity HiBiT tag.
In the presence of the large NanoLuc subunit (LgBiT), complementation occurs,
reconstituting a full-length functional NanoLuc Luciferase. Here, we have used
complemented luminescence to monitor the internalization of the A1AR
in living HEK293 cells. Agonist treatment resulted in a robust decrease in
cell-surface luminescence, indicating an increase in A1AR
internalization. These responses were inhibited by the A1AR-selective
antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), with an antagonist
affinity that closely matched that measured using ligand binding with a
fluorescent A1 receptor antagonist (CA200645). The agonist potencies
for inducing A1AR internalization were very similar to the affinities
previously determined by ligand binding, suggesting little or no amplification
of the internalization response. By complementing the HiBiT tag to exogenous
purified LgBiT, it was also possible to perform NanoBRET ligand-binding
experiments using HiBiT–A1AR. This study demonstrates the use of
NanoBiT technology to monitor internalization of the A1AR and offers
the potential to combine these experiments with NanoBRET ligand-binding
assays.
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Affiliation(s)
- Mark Soave
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, UK
| | - Barrie Kellam
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, UK.,School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, UK
| | - Stephen J Briddon
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, UK
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, UK
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22
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Luminescence- and Fluorescence-Based Complementation Assays to Screen for GPCR Oligomerization: Current State of the Art. Int J Mol Sci 2019; 20:ijms20122958. [PMID: 31213021 PMCID: PMC6627893 DOI: 10.3390/ijms20122958] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/05/2019] [Accepted: 06/12/2019] [Indexed: 01/22/2023] Open
Abstract
G protein-coupled receptors (GPCRs) have the propensity to form homo- and heterodimers. Dysfunction of these dimers has been associated with multiple diseases, e.g., pre-eclampsia, schizophrenia, and depression, among others. Over the past two decades, considerable efforts have been made towards the development of screening assays for studying these GPCR dimer complexes in living cells. As a first step, a robust in vitro assay in an overexpression system is essential to identify and characterize specific GPCR–GPCR interactions, followed by methodologies to demonstrate association at endogenous levels and eventually in vivo. This review focuses on protein complementation assays (PCAs) which have been utilized to study GPCR oligomerization. These approaches are typically fluorescence- and luminescence-based, making identification and localization of protein–protein interactions feasible. The GPCRs of interest are fused to complementary fluorescent or luminescent fragments that, upon GPCR di- or oligomerization, may reconstitute to a functional reporter, of which the activity can be measured. Various protein complementation assays have the disadvantage that the interaction between the reconstituted split fragments is irreversible, which can lead to false positive read-outs. Reversible systems offer several advantages, as they do not only allow to follow the kinetics of GPCR–GPCR interactions, but also allow evaluation of receptor complex modulation by ligands (either agonists or antagonists). Protein complementation assays may be used for high throughput screenings as well, which is highly relevant given the growing interest and effort to identify small molecule drugs that could potentially target disease-relevant dimers. In addition to providing an overview on how PCAs have allowed to gain better insights into GPCR–GPCR interactions, this review also aims at providing practical guidance on how to perform PCA-based assays.
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23
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Mahmod Al-Qattan MN, Mordi MN. Molecular Basis of Modulating Adenosine Receptors Activities. Curr Pharm Des 2019; 25:817-831. [DOI: 10.2174/1381612825666190304122624] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 02/26/2019] [Indexed: 01/04/2023]
Abstract
Modulating cellular processes through extracellular chemical stimuli is medicinally an attractive approach to control disease conditions. GPCRs are the most important group of transmembranal receptors that produce different patterns of activations using intracellular mediators (such as G-proteins and Beta-arrestins). Adenosine receptors (ARs) belong to GPCR class and are divided into A1AR, A2AAR, A2BAR and A3AR. ARs control different physiological activities thus considered valuable target to control neural, heart, inflammatory and other metabolic disorders. Targeting ARs using small molecules essentially works by binding orthosteric and/or allosteric sites of the receptors. Although targeting orthosteric site is considered typical to modulate receptor activity, allosteric sites provide better subtype selectivity, saturable modulation of activity and variable activation patterns. Each receptor exists in dynamical equilibrium between conformational ensembles. The equilibrium is affected by receptor interaction with other molecules. Changing the population of conformational ensembles of the receptor is the method by which orthosteric, allosteric and other cellular components control receptor signaling. Herein, the interactions of ARs with orthosteric, allosteric ligands as well as intracellular mediators are described. A quinary interaction model for the receptor is proposed and energy wells for major conformational ensembles are retrieved.
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Affiliation(s)
| | - Mohd Nizam Mordi
- Centre For Drug Research, Universiti Sains Malaysia, 11800 Gelugor, Penang, Malaysia
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24
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Dale NC, Johnstone EKM, White CW, Pfleger KDG. NanoBRET: The Bright Future of Proximity-Based Assays. Front Bioeng Biotechnol 2019; 7:56. [PMID: 30972335 PMCID: PMC6443706 DOI: 10.3389/fbioe.2019.00056] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/04/2019] [Indexed: 12/17/2022] Open
Abstract
Bioluminescence resonance energy transfer (BRET) is a biophysical technique used to monitor proximity within live cells. BRET exploits the naturally occurring phenomenon of dipole-dipole energy transfer from a donor enzyme (luciferase) to an acceptor fluorophore following enzyme-mediated oxidation of a substrate. This results in production of a quantifiable signal that denotes proximity between proteins and/or molecules tagged with complementary luciferase and fluorophore partners. BRET assays have been used to observe an array of biological functions including ligand binding, intracellular signaling, receptor-receptor proximity, and receptor trafficking, however, BRET assays can theoretically be used to monitor the proximity of any protein or molecule for which appropriate fusion constructs and/or fluorophore conjugates can be produced. Over the years, new luciferases and approaches have been developed that have increased the potential applications for BRET assays. In particular, the development of the small, bright and stable Nanoluciferase (NanoLuc; Nluc) and its use in NanoBRET has vastly broadened the potential applications of BRET assays. These advances have exciting potential to produce new experimental methods to monitor protein-protein interactions (PPIs), protein-ligand interactions, and/or molecular proximity. In addition to NanoBRET, Nluc has also been exploited to produce NanoBiT technology, which further broadens the scope of BRET to monitor biological function when NanoBiT is combined with an acceptor. BRET has proved to be a powerful tool for monitoring proximity and interaction, and these recent advances further strengthen its utility for a range of applications.
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Affiliation(s)
- Natasha C Dale
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia.,Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia.,Australian Research Council Centre for Personalised Therapeutics TechnologiesAustralia
| | - Elizabeth K M Johnstone
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia.,Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia.,Australian Research Council Centre for Personalised Therapeutics TechnologiesAustralia
| | - Carl W White
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia.,Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia.,Australian Research Council Centre for Personalised Therapeutics TechnologiesAustralia
| | - Kevin D G Pfleger
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia.,Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia.,Australian Research Council Centre for Personalised Therapeutics TechnologiesAustralia.,Dimerix Limited, Nedlands, WA, Australia
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Probing structure-activity relationship in β-arrestin2 recruitment of diversely substituted adenosine derivatives. Biochem Pharmacol 2018; 158:103-113. [PMID: 30292756 DOI: 10.1016/j.bcp.2018.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 10/02/2018] [Indexed: 12/18/2022]
Abstract
In the adenosine receptor (AR) subfamily of G protein-coupled receptors (GPCRs), biased agonism has been described for the human A1AR, A2BAR and A3AR. While diverse A3AR agonists have been evaluated for receptor binding and Gi-mediated cAMP signalling, the β-arrestin2 (βarr2) pathway has been left largely unexplored. We screened nineteen diverse adenosine derivatives for βarr2 recruitment using a stable hA3AR-NanoBit®-βarr2 HEK293T cell line. Their activity profiles were compared with a cAMP accumulation assay in stable hA3AR CHO cells. Structural features linked to βarr2 activation were further investigated by the evaluation of an additional ten A3AR ligands. The A3AR-selective reference agonist 2-Cl-IB-MECA, which is a full agonist in terms of cAMP inhibition, only showed partial agonist behaviour in βarr2 recruitment. Highly A3AR-selective (N)-methanocarba 5'-uronamide adenosine derivatives displayed higher potency in both cAMP signalling and βarr2 recruitment than reference agonists NECA and 2-Cl-IB-MECA. Their A3AR-preferred conformation tolerates C2-position substitutions, for increased βarr2 efficacy, better than the flexible scaffolds of ribose derivatives. The different amino functionalities in the adenosine scaffold of these derivatives each seem to be important for signalling as well. In conclusion, we have provided insights into ligand features that can help to guide the future therapeutic development of biased A3AR ligands with respect to G-protein and βarr2 signalling.
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Selected Literature Watch. J Caffeine Adenosine Res 2018. [DOI: 10.1089/caff.2018.29008.slw] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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