1
|
Cullum SA, Platt S, Dale N, Isaac OC, Wragg ES, Soave M, Veprintsev DB, Woolard J, Kilpatrick LE, Hill SJ. Mechano-sensitivity of β2-adrenoceptors enhances constitutive activation of cAMP generation that is inhibited by inverse agonists. Commun Biol 2024; 7:417. [PMID: 38580813 PMCID: PMC10997663 DOI: 10.1038/s42003-024-06128-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 03/29/2024] [Indexed: 04/07/2024] Open
Abstract
The concept of agonist-independent signalling that can be attenuated by inverse agonists is a fundamental element of the cubic ternary complex model of G protein-coupled receptor (GPCR) activation. This model shows how a GPCR can exist in two conformational states in the absence of ligands; an inactive R state and an active R* state that differ in their affinities for agonists, inverse agonists, and G-protein alpha subunits. The proportion of R* receptors that exist in the absence of agonists determines the level of constitutive receptor activity. In this study we demonstrate that mechanical stimulation can induce β2-adrenoceptor agonist-independent Gs-mediated cAMP signalling that is sensitive to inhibition by inverse agonists such as ICI-118551 and propranolol. The size of the mechano-sensitive response is dependent on the cell surface receptor expression level in HEK293G cells, is still observed in a ligand-binding deficient D113A mutant β2-adrenoceptor and can be attenuated by site-directed mutagenesis of the extracellular N-glycosylation sites on the N-terminus and second extracellular loop of the β2-adrenoceptor. Similar mechano-sensitive agonist-independent responses are observed in HEK293G cells overexpressing the A2A-adenosine receptor. These data provide new insights into how agonist-independent constitutive receptor activity can be enhanced by mechanical stimulation and regulated by inverse agonists.
Collapse
Affiliation(s)
- Sean A Cullum
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
- Centre of Membrane Proteins and Receptors, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Simon Platt
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
- Centre of Membrane Proteins and Receptors, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Natasha Dale
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
- Centre of Membrane Proteins and Receptors, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Oliver C Isaac
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
- Centre of Membrane Proteins and Receptors, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Edward S Wragg
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
- Centre of Membrane Proteins and Receptors, University of Nottingham, Nottingham, NG7 2UH, UK
| | - 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, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Dmitry B Veprintsev
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
- Centre of Membrane Proteins and Receptors, University of Nottingham, Nottingham, NG7 2UH, 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, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Laura E Kilpatrick
- Centre of Membrane Proteins and Receptors, University of Nottingham, Nottingham, NG7 2UH, UK
- Division of Bimolecular Science and Medicinal Chemistry, School of Pharmacy, Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, 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, University of Nottingham, Nottingham, NG7 2UH, UK.
| |
Collapse
|
2
|
White CW, Platt S, Kilpatrick LE, Dale N, Abhayawardana RS, Dekkers S, Kindon ND, Kellam B, Stocks MJ, Pfleger KDG, Hill SJ. CXCL17 is an allosteric inhibitor of CXCR4 through a mechanism of action involving glycosaminoglycans. Sci Signal 2024; 17:eabl3758. [PMID: 38502733 PMCID: PMC7615768 DOI: 10.1126/scisignal.abl3758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 02/29/2024] [Indexed: 03/21/2024]
Abstract
CXCL17 is a chemokine principally expressed by mucosal tissues, where it facilitates chemotaxis of monocytes, dendritic cells, and macrophages and has antimicrobial properties. CXCL17 is also implicated in the pathology of inflammatory disorders and progression of several cancers, and its expression is increased during viral infections of the lung. However, the exact role of CXCL17 in health and disease requires further investigation, and there is a need for confirmed molecular targets mediating CXCL17 functional responses. Using a range of bioluminescence resonance energy transfer (BRET)-based assays, here we demonstrated that CXCL17 inhibited CXCR4-mediated signaling and ligand binding. Moreover, CXCL17 interacted with neuropillin-1, a VEGFR2 coreceptor. In addition, we found that CXCL17 only inhibited CXCR4 ligand binding in intact cells and demonstrated that this effect was mimicked by known glycosaminoglycan binders, surfen and protamine sulfate. Disruption of putative GAG binding domains in CXCL17 prevented CXCR4 binding. This indicated that CXCL17 inhibited CXCR4 by a mechanism of action that potentially required the presence of a glycosaminoglycan-containing accessory protein. Together, our results revealed that CXCL17 is an endogenous inhibitor of CXCR4 and represents the next step in our understanding of the function of CXCL17 and regulation of CXCR4 signaling.
Collapse
Affiliation(s)
- Carl W. White
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, United Kingdom
- 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, Western Australia 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Australia
- Dimerix Limited, Melbourne, Australia
| | - Simon Platt
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, United Kingdom
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Laura E. Kilpatrick
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
- School of Pharmacy, Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Natasha Dale
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Australia
| | - Rekhati S. Abhayawardana
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Australia
| | - Sebastian Dekkers
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, United Kingdom
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
- School of Pharmacy, Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Nicholas D Kindon
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
- School of Pharmacy, Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Barrie Kellam
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
- School of Pharmacy, Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Michael J Stocks
- School of Pharmacy, Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Kevin D. G. Pfleger
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, QEII Medical Centre, Nedlands, Western Australia 6009, Australia
- Australian Research Council Centre for Personalised Therapeutics Technologies, Australia
- Dimerix Limited, Melbourne, Australia
| | - Stephen J. Hill
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, United Kingdom
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| |
Collapse
|
3
|
Dekkers S, Comez D, Karsai N, Arimont-Segura M, Canals M, Caspar B, de Graaf C, Kilpatrick LE, Leurs R, Kellam B, Hill SJ, Briddon SJ, Stocks MJ. Small Molecule Fluorescent Ligands for the Atypical Chemokine Receptor 3 (ACKR3). ACS Med Chem Lett 2024; 15:143-148. [PMID: 38229752 PMCID: PMC10788940 DOI: 10.1021/acsmedchemlett.3c00469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 11/24/2023] [Accepted: 11/29/2023] [Indexed: 01/18/2024] Open
Abstract
The atypical chemokine receptor 3 (ACKR3) is a receptor that induces cancer progression and metastasis in multiple cell types. Therefore, new chemical tools are required to study the role of ACKR3 in cancer and other diseases. In this study, fluorescent probes, based on a series of small molecule ACKR3 agonists, were synthesized. Three fluorescent probes, which showed specific binding to ACKR3 through a luminescence-based NanoBRET binding assay (pKd ranging from 6.8 to 7.8) are disclosed. Due to their high affinity at the ACKR3, we have shown their application in both competition binding experiments and confocal microscopy studies showing the cellular distribution of this receptor.
Collapse
Affiliation(s)
- Sebastian Dekkers
- Biodiscovery
Institute, School of Pharmacy, University
of Nottingham, Nottingham NG7 2RD, United
Kingdom
| | - Dehan Comez
- Centre
of Membrane Proteins and Receptors, University
of Birmingham and University of Nottingham, The Midlands NG7 2UH, United Kingdom
- Division
of Physiology, Pharmacology & Neuroscience, Medical School, University of Nottingham, Nottingham NG7 2UH, U.K.
| | - Noemi Karsai
- Centre
of Membrane Proteins and Receptors, University
of Birmingham and University of Nottingham, The Midlands NG7 2UH, United Kingdom
- Division
of Physiology, Pharmacology & Neuroscience, Medical School, University of Nottingham, Nottingham NG7 2UH, U.K.
| | - Marta Arimont-Segura
- Division
of Medicinal Chemistry, Amsterdam Institute of Molecular and Life
Sciences (AIMMS), Faculty of Science, Vrije
Universiteit Amsterdam, De Boelelaan 1108, Amsterdam 1081 HZ, The Netherlands
| | - Meritxell Canals
- Centre
of Membrane Proteins and Receptors, University
of Birmingham and University of Nottingham, The Midlands NG7 2UH, United Kingdom
- Division
of Physiology, Pharmacology & Neuroscience, Medical School, University of Nottingham, Nottingham NG7 2UH, U.K.
| | - Birgit Caspar
- Centre
of Membrane Proteins and Receptors, University
of Birmingham and University of Nottingham, The Midlands NG7 2UH, United Kingdom
- Division
of Physiology, Pharmacology & Neuroscience, Medical School, University of Nottingham, Nottingham NG7 2UH, U.K.
| | - Chris de Graaf
- Division
of Medicinal Chemistry, Amsterdam Institute of Molecular and Life
Sciences (AIMMS), Faculty of Science, Vrije
Universiteit Amsterdam, De Boelelaan 1108, Amsterdam 1081 HZ, The Netherlands
| | - Laura E. Kilpatrick
- Biodiscovery
Institute, School of Pharmacy, University
of Nottingham, Nottingham NG7 2RD, United
Kingdom
- Centre
of Membrane Proteins and Receptors, University
of Birmingham and University of Nottingham, The Midlands NG7 2UH, United Kingdom
| | - Rob Leurs
- Division
of Medicinal Chemistry, Amsterdam Institute of Molecular and Life
Sciences (AIMMS), Faculty of Science, Vrije
Universiteit Amsterdam, De Boelelaan 1108, Amsterdam 1081 HZ, The Netherlands
| | - Barrie Kellam
- Biodiscovery
Institute, School of Pharmacy, University
of Nottingham, Nottingham NG7 2RD, United
Kingdom
- Centre
of Membrane Proteins and Receptors, University
of Birmingham and University of Nottingham, The Midlands NG7 2UH, United Kingdom
| | - Stephen J. Hill
- Centre
of Membrane Proteins and Receptors, University
of Birmingham and University of Nottingham, The Midlands NG7 2UH, United Kingdom
- Division
of Physiology, Pharmacology & Neuroscience, Medical School, University of Nottingham, Nottingham NG7 2UH, U.K.
| | - Stephen J. Briddon
- Centre
of Membrane Proteins and Receptors, University
of Birmingham and University of Nottingham, The Midlands NG7 2UH, United Kingdom
- Division
of Physiology, Pharmacology & Neuroscience, Medical School, University of Nottingham, Nottingham NG7 2UH, U.K.
| | - Michael J. Stocks
- Biodiscovery
Institute, School of Pharmacy, University
of Nottingham, Nottingham NG7 2RD, United
Kingdom
| |
Collapse
|
4
|
Ogrodzinski L, Platt S, Goulding J, Alexander C, Farr TD, Woolard J, Hill SJ, Kilpatrick LE. Probing expression of E-selectin using CRISPR-Cas9-mediated tagging with HiBiT in human endothelial cells. iScience 2023; 26:107232. [PMID: 37496673 PMCID: PMC10366498 DOI: 10.1016/j.isci.2023.107232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 05/30/2023] [Accepted: 06/23/2023] [Indexed: 07/28/2023] Open
Abstract
E-selectin is expressed on endothelial cells in response to inflammatory cytokines and mediates leukocyte rolling and extravasation. However, studies have been hampered by lack of experimental approaches to monitor expression in real time in living cells. Here, NanoLuc Binary Technology (NanoBiT) in conjunction with CRISPR-Cas9 genome editing was used to tag endogenous E-selectin in human umbilical vein endothelial cells (HUVECs) with the 11 amino acid nanoluciferase fragment HiBiT. Addition of the membrane-impermeable complementary fragment LgBiT allowed detection of cell surface expression. This allowed the effect of inflammatory mediators on E-selectin expression to be monitored in real time in living endothelial cells. NanoBiT combined with CRISPR-Cas9 gene editing allows sensitive monitoring of real-time changes in cell surface expression of E-selectin and offers a powerful tool for future drug discovery efforts aimed at this important inflammatory protein.
Collapse
Affiliation(s)
- Lydia Ogrodzinski
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, NG7 2UH Nottingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, Nottingham, UK
| | - Simon Platt
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, NG7 2UH Nottingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, Nottingham, UK
| | - Joelle Goulding
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, NG7 2UH Nottingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, Nottingham, UK
| | - Cameron Alexander
- Division of Molecular Therapeutics and Formulation, School of Pharmacy, Boots Building, University of Nottingham, NG7 2RD Nottingham, UK
| | - Tracy D. Farr
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, NG7 2UH Nottingham, UK
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, NG7 2UH Nottingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, Nottingham, UK
| | - Stephen J. Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, NG7 2UH Nottingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, Nottingham, UK
| | - Laura E. Kilpatrick
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, Nottingham, UK
- Division of Bimolecular Science and Medicinal Chemistry, School of Pharmacy, Biodiscovery Institute, University of Nottingham, NG7 2RD Nottingham, UK
| |
Collapse
|
5
|
Van Daele M, Kilpatrick LE, Woolard J, Hill SJ. Characterisation of tyrosine kinase inhibitor-receptor interactions at VEGFR2 using sunitinib-red and nanoBRET. Biochem Pharmacol 2023:115672. [PMID: 37406966 DOI: 10.1016/j.bcp.2023.115672] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/13/2023] [Accepted: 06/26/2023] [Indexed: 07/07/2023]
Abstract
Vascular endothelial growth factor (VEGF) is an important mediator of angiogenesis, proliferation and migration of vascular endothelial cells. It is well known that cardiovascular safety liability for a wide range of small molecule tyrosine kinase inhibitors (TKIs) can result from interference with the VEGFR2 signalling system. In this study we have developed a ligand-binding assay using a fluorescent analogue of sunitinib (sunitinib-red) and full length VEGFR2 tagged on its C-terminus with the bioluminescent protein nanoluciferase to monitor ligand-binding to VEGFR2 using bioluminescence resonance energy transfer (BRET). This NanoBRET assay is a proximity-based assay (requiring the fluorescent and bioluminescent components to be within 10nm of each other) that can monitor the binding of ligands to the kinase domain of VEGFR2. Sunitinib-red was not membrane permeable but was able to monitor the binding affinity and kinetics of a range of TKIs in cell lysates. Kinetic studies showed that sunitinib-red bound rapidly to VEGFR2 at 25 °C and that cediranib had slower binding kinetics with an average residence time of 112 min. Comparison between the log Ki values for inhibition of binding of sunitinib-red and log IC50 values for attenuation of VEGF165a-stimulated NFAT responses showed very similar values for compounds that inhibited sunitinib-red binding. However, two compounds that failed to inhibit sunitinib-red binding (dasatinib and entospletinib) were still able to attenuate VEGFR2-mediated NFAT signalling through inhibition of downstream signalling events. These results suggest that these compounds may still exhibit cardiovascular liabilities as a result of interference with downstream VEGFR2 signalling.
Collapse
Affiliation(s)
- Marieke Van Daele
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, UK
| | - Laura E Kilpatrick
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, UK; Division of Bimolecular Science and Medicinal Chemistry, School of Pharmacy, Biodiscovery Institute, University of 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, University of Birmingham and 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, University of Birmingham and Nottingham, The Midlands, UK.
| |
Collapse
|
6
|
Hill SJ, Kilpatrick LE. Kinetic analysis of fluorescent ligand binding to cell surface receptors: Insights into conformational changes and allosterism in living cells. Br J Pharmacol 2023. [PMID: 37386806 DOI: 10.1111/bph.16185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/02/2023] [Accepted: 06/20/2023] [Indexed: 07/01/2023] Open
Abstract
Equilibrium binding assays are one of the mainstays of current drug discovery efforts to evaluate the interaction of drugs with receptors in membranes and intact cells. However, in recent years there has been increased focus on the kinetics of the drug-receptor interaction to gain insight into the lifetime of drug-receptor complexes and the rate of association of a ligand with its receptor. Furthermore, drugs that act on topically distinct sites (allosteric) from those occupied by the endogenous ligand (orthosteric site) can induce conformational changes in the orthosteric binding site leading to changes in the association and/or dissociation rate constants of orthosteric ligands. Conformational changes in the orthosteric ligand binding site can also be induced through interaction with neighbouring accessory proteins and receptor homo- and hetero-dimerization. In this review, we provide an overview of the use of fluorescent ligand technologies to interrogate ligand-receptor kinetics in living cells and the novel insights that they can provide into the conformational changes induced by drugs acting on a variety of cell surface receptors including G protein-coupled receptors (GPCRs), receptor tyrosine kinases (RTKs) and cytokine receptors.
Collapse
Affiliation(s)
- 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, University of Birmingham and Nottingham, The Midlands, UK
| | - Laura E Kilpatrick
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, UK
- Division of Bimolecular Science and Medicinal Chemistry, School of Pharmacy, Biodiscovery Institute, University of Nottingham, NG7 2RD, UK
| |
Collapse
|
7
|
Lay CS, Kilpatrick LE, Craggs PD, Hill SJ. Use of NanoBiT and NanoBRET to characterise interleukin-23 receptor dimer formation in living cells. Br J Pharmacol 2023; 180:1444-1459. [PMID: 36560872 PMCID: PMC10953408 DOI: 10.1111/bph.16018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 12/02/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND AND PURPOSE Interleukin-23 (IL-23) and its receptor are important drug targets for the treatment of auto-inflammatory diseases. IL-23 binds to a receptor complex composed of two single transmembrane spanning proteins IL23R and IL12Rβ1. In this study, we aimed to gain further understanding of how ligand binding induces signalling of IL-23 receptor complexes using the proximity-based techniques of NanoLuc Binary Technology (NanoBiT) and Bioluminescence Resonance Energy Transfer (BRET). EXPERIMENTAL APPROACH To monitor the formation of IL-23 receptor complexes, we developed a split luciferase (NanoBiT) assay whereby heteromerisation of receptor subunits can be measured through luminescence. The affinity of NanoBiT complemented complexes for IL-23 was measured using NanoBRET, and cytokine-induced signal transduction was measured using a phospho-STAT3 AlphaLISA assay. KEY RESULTS NanoBiT measurements demonstrated that IL-23 receptor complexes formed to an equal degree in the presence and absence of ligand. NanoBRET measurements confirmed that these complexes bound IL-23 with a picomolar binding affinity. Measurement of STAT3 phosphorylation demonstrated that pre-formed IL-23 receptor complexes induced signalling following ligand binding. It was also demonstrated that synthetic ligand-independent signalling could be induced by high affinity (HiBit) but not low affinity (SmBit) NanoBiT crosslinking of the receptor N-terminal domains. CONCLUSIONS AND IMPLICATIONS These results indicate that receptor complexes form prior to ligand binding and are not sufficient to induce signalling alone. Our findings indicate that IL-23 induces a conformational change in heteromeric receptor complexes, to enable signal transduction. These observations have direct implications for drug discovery efforts to target the IL-23 receptor.
Collapse
Affiliation(s)
- Charles S. Lay
- Division of Physiology, Pharmacology and Neuroscience, School of Life SciencesUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and ReceptorsUniversity of Birmingham and NottinghamThe MidlandsUK
- Medicine Design, Medicinal Science and TechnologyGlaxoSmithKlineStevenageUK
| | - Laura E. Kilpatrick
- Centre of Membrane Proteins and ReceptorsUniversity of Birmingham and NottinghamThe MidlandsUK
- Division of Bimolecular Science and Medicinal Chemistry, School of Pharmacy, Biodiscovery InstituteUniversity of NottinghamNottinghamUK
| | - Peter D. Craggs
- Medicine Design, Medicinal Science and TechnologyGlaxoSmithKlineStevenageUK
- Crick‐GSK Biomedical LinklabsGlaxoSmithKlineStevenageUK
| | - Stephen J. Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life SciencesUniversity of NottinghamNottinghamUK
- Centre of Membrane Proteins and ReceptorsUniversity of Birmingham and NottinghamThe MidlandsUK
| |
Collapse
|
8
|
Lay CS, Isidro-Llobet A, Kilpatrick LE, Craggs PD, Hill SJ. Characterisation of IL-23 receptor antagonists and disease relevant mutants using fluorescent probes. Nat Commun 2023; 14:2882. [PMID: 37208328 PMCID: PMC10199020 DOI: 10.1038/s41467-023-38541-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 05/08/2023] [Indexed: 05/21/2023] Open
Abstract
Association of single nucleotide polymorphisms in the IL-23 receptor with several auto-inflammatory diseases, led to the heterodimeric receptor and its cytokine-ligand IL-23, becoming important drug targets. Successful antibody-based therapies directed against the cytokine have been licenced and a class of small peptide antagonists of the receptor have entered clinical trials. These peptide antagonists may offer therapeutic advantages over existing anti-IL-23 therapies, but little is known about their molecular pharmacology. In this study, we use a fluorescent version of IL-23 to characterise antagonists of the full-length receptor expressed by living cells using a NanoBRET competition assay. We then develop a cyclic peptide fluorescent probe, specific to the IL23p19:IL23R interface and use this molecule to characterise further receptor antagonists. Finally, we use the assays to study the immunocompromising C115Y IL23R mutation, demonstrating that the mechanism of action is a disruption of the binding epitope for IL23p19.
Collapse
Affiliation(s)
- Charles S Lay
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, UK
- Chemical Biology, Medicine Design, GlaxoSmithKline, Stevenage, SG1 2NY, UK
| | | | - Laura E Kilpatrick
- Centre of Membrane Proteins and Receptors, University of Birmingham and Nottingham, The Midlands, UK
- Division of Bimolecular Science and Medicinal Chemistry, School of Pharmacy, Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Peter D Craggs
- Chemical Biology, Medicine Design, GlaxoSmithKline, Stevenage, SG1 2NY, UK.
- Crick-GSK Biomedical Linklabs, Medicine Design, GlaxoSmithKline, Stevenage, SG1 2NY, 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, University of Birmingham and Nottingham, The Midlands, UK.
| |
Collapse
|
9
|
van den Bor J, Bergkamp ND, Anbuhl SM, Dekker F, Comez D, Perez Almeria CV, Bosma R, White CW, Kilpatrick LE, Hill SJ, Siderius M, Smit MJ, Heukers R. NanoB 2 to monitor interactions of ligands with membrane proteins by combining nanobodies and NanoBRET. Cell Rep Methods 2023; 3:100422. [PMID: 37056381 PMCID: PMC10088090 DOI: 10.1016/j.crmeth.2023.100422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/31/2023] [Accepted: 02/17/2023] [Indexed: 03/14/2023]
Abstract
The therapeutic potential of ligands targeting disease-associated membrane proteins is predicted by ligand-receptor binding constants, which can be determined using NanoLuciferase (NanoLuc)-based bioluminescence resonance energy transfer (NanoBRET) methods. However, the broad applicability of these methods is hampered by the restricted availability of fluorescent probes. We describe the use of antibody fragments, like nanobodies, as universal building blocks for fluorescent probes for use in NanoBRET. Our nanobody-NanoBRET (NanoB2) workflow starts with the generation of NanoLuc-tagged receptors and fluorescent nanobodies, enabling homogeneous, real-time monitoring of nanobody-receptor binding. Moreover, NanoB2 facilitates the assessment of receptor binding of unlabeled ligands in competition binding experiments. The broad significance is illustrated by the successful application of NanoB2 to different drug targets (e.g., multiple G protein-coupled receptors [GPCRs] and a receptor tyrosine kinase [RTK]) at distinct therapeutically relevant binding sites (i.e., extracellular and intracellular).
Collapse
Affiliation(s)
- Jelle van den Bor
- Receptor Biochemistry and Signaling group, Division of Medicinal Chemistry, Amsterdam Institute for Molecular and Life Science (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Nick D. Bergkamp
- Receptor Biochemistry and Signaling group, Division of Medicinal Chemistry, Amsterdam Institute for Molecular and Life Science (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Stephanie M. Anbuhl
- Receptor Biochemistry and Signaling group, Division of Medicinal Chemistry, Amsterdam Institute for Molecular and Life Science (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- QVQ Holding B.V., Utrecht, the Netherlands
| | - Françoise Dekker
- Receptor Biochemistry and Signaling group, Division of Medicinal Chemistry, Amsterdam Institute for Molecular and Life Science (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Dehan Comez
- Cell Signalling Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, the Midlands, UK
| | - Claudia V. Perez Almeria
- Receptor Biochemistry and Signaling group, Division of Medicinal Chemistry, Amsterdam Institute for Molecular and Life Science (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Reggie Bosma
- Receptor Biochemistry and Signaling group, Division of Medicinal Chemistry, Amsterdam Institute for Molecular and Life Science (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Carl W. White
- Cell Signalling Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, the Midlands, UK
| | - Laura E. Kilpatrick
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, the Midlands, UK
- Division of Bimolecular Science and Medicinal Chemistry, School of Pharmacy, Biodiscovery Institute, University of Nottingham, Nottingham, UK
| | - Stephen J. Hill
- Cell Signalling Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, the Midlands, UK
| | - Marco Siderius
- Receptor Biochemistry and Signaling group, Division of Medicinal Chemistry, Amsterdam Institute for Molecular and Life Science (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Martine J. Smit
- Receptor Biochemistry and Signaling group, Division of Medicinal Chemistry, Amsterdam Institute for Molecular and Life Science (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Raimond Heukers
- Receptor Biochemistry and Signaling group, Division of Medicinal Chemistry, Amsterdam Institute for Molecular and Life Science (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- QVQ Holding B.V., Utrecht, the Netherlands
| |
Collapse
|
10
|
Dekkers S, Caspar B, Goulding J, Kindon ND, Kilpatrick LE, Stoddart LA, Briddon SJ, Kellam B, Hill SJ, Stocks MJ. Small-Molecule Fluorescent Ligands for the CXCR4 Chemokine Receptor. J Med Chem 2023; 66:5208-5222. [PMID: 36944083 PMCID: PMC10108349 DOI: 10.1021/acs.jmedchem.3c00151] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
The C-X-C chemokine receptor type 4, or CXCR4, is a chemokine receptor found to promote cancer progression and metastasis of various cancer cell types. To investigate the pharmacology of this receptor, and to further elucidate its role in cancer, novel chemical tools are a necessity. In the present study, using classic medicinal chemistry approaches, small-molecule-based fluorescent probes were designed and synthesized based on previously reported small-molecule antagonists. Here, we report the development of three distinct chemical classes of fluorescent probes that show specific binding to the CXCR4 receptor in a novel fluorescence-based NanoBRET binding assay (pKD ranging 6.6-7.1). Due to their retained affinity at CXCR4, we furthermore report their use in competition binding experiments and confocal microscopy to investigate the pharmacology and cellular distribution of this receptor.
Collapse
Affiliation(s)
- Sebastian Dekkers
- Biodiscovery Institute, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Birgit Caspar
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
- Division of Physiology, Pharmacology & Neuroscience, Medical School, University of Nottingham, Nottingham NG7 2UH, U.K
| | - Joëlle Goulding
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
- Division of Physiology, Pharmacology & Neuroscience, Medical School, University of Nottingham, Nottingham NG7 2UH, U.K
| | - Nicholas D Kindon
- Biodiscovery Institute, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K
| | - Laura E Kilpatrick
- Biodiscovery Institute, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| | - Leigh A Stoddart
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
- Division of Physiology, Pharmacology & Neuroscience, Medical School, University of Nottingham, Nottingham NG7 2UH, U.K
| | - Stephen J Briddon
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
- Division of Physiology, Pharmacology & Neuroscience, Medical School, University of Nottingham, Nottingham NG7 2UH, U.K
| | - Barrie Kellam
- Biodiscovery Institute, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| | - Stephen J Hill
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
- Division of Physiology, Pharmacology & Neuroscience, Medical School, University of Nottingham, Nottingham NG7 2UH, U.K
| | - Michael J Stocks
- Biodiscovery Institute, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, U.K
| |
Collapse
|
11
|
Comez D, Glenn J, Anbuhl SM, Heukers R, Smit MJ, Hill SJ, Kilpatrick LE. Fluorescently tagged nanobodies and NanoBRET to study ligand-binding and agonist-induced conformational changes of full-length EGFR expressed in living cells. Front Immunol 2022; 13:1006718. [PMID: 36505413 PMCID: PMC9726709 DOI: 10.3389/fimmu.2022.1006718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/31/2022] [Indexed: 11/24/2022] Open
Abstract
Introduction The Epidermal Growth Factor Receptor is a member of the Erb receptor tyrosine kinase family. It binds several ligands including EGF, betacellulin (BTC) and TGF-α, controls cellular proliferation and invasion and is overexpressed in various cancer types. Nanobodies (VHHs) are the antigen binding fragments of heavy chain only camelid antibodies. In this paper we used NanoBRET to compare the binding characteristics of fluorescent EGF or two distinct fluorescently labelled EGFR directed nanobodies (Q44c and Q86c) to full length EGFR. Methods Living HEK293T cells were stably transfected with N terminal NLuc tagged EGFR. NanoBRET saturation, displacement or kinetics experiments were then performed using fluorescently labelled EGF ligands (EGF-AF488 or EGF-AF647) or fluorescently labelled EGFR targeting nanobodies (Q44c-HL488 and Q86c-HL488). Results These data revealed that the EGFR nanobody Q44c was able to inhibit EGF binding to full length EGFR, while Q86c was able to recognise agonist bound EGFR and act as a conformational sensor. The specific binding of fluorescent Q44c-HL488 and EGF-AF488 was inhibited by a range of EGFR ligands (EGF> BTC>TGF-α). Discussion EGFR targeting nanobodies are powerful tools for studying the role of the EGFR in health and disease and allow real time quantification of ligand binding and distinct ligand induced conformational changes.
Collapse
Affiliation(s)
- Dehan Comez
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands Nottingham, Nottingham, United Kingdom
| | - Jacqueline Glenn
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands Nottingham, Nottingham, United Kingdom
| | - Stephanie M Anbuhl
- Division of Medicinal Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS) Vrije Universiteit (VU), Amsterdam, Netherlands.,QVQ Holding BV, Utrecht, Netherlands
| | - Raimond Heukers
- Division of Medicinal Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS) Vrije Universiteit (VU), Amsterdam, Netherlands.,QVQ Holding BV, Utrecht, Netherlands
| | - Martine J Smit
- Division of Medicinal Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS) Vrije Universiteit (VU), Amsterdam, Netherlands
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands Nottingham, Nottingham, United Kingdom
| | - Laura E Kilpatrick
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands Nottingham, Nottingham, United Kingdom.,Division of Bimolecular Science and Medicinal Chemistry, Biodiscovery Institute, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom
| |
Collapse
|
12
|
Peach CJ, Kilpatrick LE, Woolard J, Hill SJ. Use of NanoBiT and NanoBRET to monitor fluorescent VEGF-A binding kinetics to VEGFR2/NRP1 heteromeric complexes in living cells. Br J Pharmacol 2021; 178:2393-2411. [PMID: 33655497 DOI: 10.1111/bph.15426] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 02/06/2021] [Accepted: 02/23/2021] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND AND PURPOSE VEGF-A is a key mediator of angiogenesis, primarily signalling via VEGF receptor 2 (VEGFR2). Endothelial cells also express the co-receptor neuropilin-1 (NRP1) that potentiates VEGF-A/VEGFR2 signalling. VEGFR2 and NRP1 had distinct real-time ligand binding kinetics when monitored using BRET. We previously characterised fluorescent VEGF-A isoforms tagged at a single site with tetramethylrhodamine (TMR). Here, we explored differences between VEGF-A isoforms in living cells that co-expressed both receptors. EXPERIMENTAL APPROACH Receptor localisation was monitored in HEK293T cells expressing both VEGFR2 and NRP1 using membrane-impermeant HaloTag and SnapTag technologies. To isolate ligand binding pharmacology at a defined VEGFR2/NRP1 complex, we developed an assay using NanoBiT complementation technology whereby heteromerisation is required for luminescence emissions. Binding affinities and kinetics of VEGFR2-selective VEGF165 b-TMR and non-selective VEGF165 a-TMR were monitored using BRET from this defined complex. KEY RESULTS Cell surface VEGFR2 and NRP1 were co-localised and formed a constitutive heteromeric complex. Despite being selective for VEGFR2, VEGF165 b-TMR had a distinct kinetic ligand binding profile at the complex that largely remained elevated in cells over 90 min. VEGF165 a-TMR bound to the VEGFR2/NRP1 complex with kinetics comparable to those of VEGFR2 alone. Using a binding-dead mutant of NRP1 did not affect the binding kinetics or affinity of VEGF165 a-TMR. CONCLUSION AND IMPLICATIONS This NanoBiT approach enabled real-time ligand binding to be quantified in living cells at 37°C from a specified complex between a receptor TK and its co-receptor for the first time.
Collapse
Affiliation(s)
- Chloe J Peach
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Laura E Kilpatrick
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
- Division of Bimolecular Sciences and Medicinal Chemistry, Biodiscovery Institute, School of Pharmacy, University of Nottingham, Nottingham, UK
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK
- Centre of Membrane Proteins and Receptors, 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, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| |
Collapse
|
13
|
Soave M, Stoddart LA, White CW, Kilpatrick LE, Goulding J, Briddon SJ, Hill SJ. Detection of genome-edited and endogenously expressed G protein-coupled receptors. FEBS J 2021; 288:2585-2601. [PMID: 33506623 PMCID: PMC8647918 DOI: 10.1111/febs.15729] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/20/2021] [Accepted: 01/25/2021] [Indexed: 12/11/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of membrane receptors and major targets for FDA-approved drugs. The ability to quantify GPCR expression and ligand binding characteristics in different cell types and tissues is therefore important for drug discovery. The advent of genome editing along with developments in fluorescent ligand design offers exciting new possibilities to probe GPCRs in their native environment. This review provides an overview of the recent technical advances employed to study the localisation and ligand binding characteristics of genome-edited and endogenously expressed GPCRs.
Collapse
Affiliation(s)
- Mark Soave
- Division of Physiology, Pharmacology and NeuroscienceSchool of Life SciencesUniversity of NottinghamUK
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
| | - Leigh A. Stoddart
- Division of Physiology, Pharmacology and NeuroscienceSchool of Life SciencesUniversity of NottinghamUK
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
| | - Carl W. White
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
- Harry Perkins Institute of Medical Research and Centre for Medical ResearchQEII Medical CentreThe University of Western AustraliaNedlandsAustralia
- Australian Research Council Centre for Personalised Therapeutics TechnologiesAustralia
| | - Laura E. Kilpatrick
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
- Division of Biomolecular Science and Medicinal ChemistrySchool of Pharmacy, Biodiscovery InstituteUniversity of NottinghamUK
| | - Joëlle Goulding
- Division of Physiology, Pharmacology and NeuroscienceSchool of Life SciencesUniversity of NottinghamUK
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
| | - Stephen J. Briddon
- Division of Physiology, Pharmacology and NeuroscienceSchool of Life SciencesUniversity of NottinghamUK
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
| | - Stephen J. Hill
- Division of Physiology, Pharmacology and NeuroscienceSchool of Life SciencesUniversity of NottinghamUK
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
| |
Collapse
|
14
|
Stoddart LA, Kilpatrick LE, Corriden R, Kellam B, Briddon SJ, Hill SJ. Efficient G protein coupling is not required for agonist-mediated internalization and membrane reorganization of the adenosine A 3 receptor. FASEB J 2021; 35:e21211. [PMID: 33710641 PMCID: PMC9328438 DOI: 10.1096/fj.202001729rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 11/03/2020] [Accepted: 11/09/2020] [Indexed: 01/09/2023]
Abstract
Organization of G protein‐coupled receptors at the plasma membrane has been the focus of much recent attention. Advanced microscopy techniques have shown that these receptors can be localized to discrete microdomains and reorganization upon ligand activation is crucial in orchestrating their signaling. Here, we have compared the membrane organization and downstream signaling of a mutant (R108A, R3.50A) of the adenosine A3 receptor (A3AR) to that of the wild‐type receptor. Fluorescence Correlation Spectroscopy (FCS) studies with a fluorescent agonist (ABEA‐X‐BY630) demonstrated that both wild‐type and mutant receptors bind agonist with high affinity but in subsequent downstream signaling assays the R108A mutation abolished agonist‐mediated inhibition of cAMP production and ERK phosphorylation. In further FCS studies, both A3AR and A3AR R108A underwent similar agonist‐induced increases in receptor density and molecular brightness which were accompanied by a decrease in membrane diffusion after agonist treatment. Using bimolecular fluorescence complementation, experiments showed that the R108A mutant retained the ability to recruit β‐arrestin and these receptor/arrestin complexes displayed similar membrane diffusion and organization to that observed with wild‐type receptors. These data demonstrate that effective G protein signaling is not a prerequisite for agonist‐stimulated β‐arrestin recruitment and membrane reorganization of the A3AR.
Collapse
Affiliation(s)
- Leigh A Stoddart
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Laura E Kilpatrick
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.,School of Pharmacy, Biodiscovery Institute, University Park Nottingham, Nottingham, UK
| | - Ross Corriden
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Barrie Kellam
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.,School of Pharmacy, Biodiscovery Institute, University Park Nottingham, Nottingham, UK
| | - Stephen J Briddon
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Stephen J Hill
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| |
Collapse
|
15
|
Kilpatrick LE, Hill SJ. Transactivation of G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs): Recent insights using luminescence and fluorescence technologies. Curr Opin Endocr Metab Res 2021; 16:102-112. [PMID: 33748531 PMCID: PMC7960640 DOI: 10.1016/j.coemr.2020.10.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Alterations in signalling due to bidirectional transactivation of G protein-coupled receptor (GPCRs) and receptor tyrosine kinases (RTKs) are well established. Transactivation significantly diversifies signalling networks within a cell and has been implicated in promoting both advantageous and disadvantageous physiological and pathophysiological outcomes, making the GPCR/RTK interactions attractive new targets for drug discovery programmes. Transactivation has been observed for a plethora of receptor pairings in multiple cell types; however, the precise molecular mechanisms and signalling effectors involved can vary with receptor pairings and cell type. This short review will discuss the recent applications of proximity-based assays, such as resonance energy transfer and fluorescence-based imaging in investigating the dynamics of GPCR/RTK complex formation, subsequent effector protein recruitment and the cellular locations of complexes in living cells.
Collapse
Key Words
- 5-hydroxytryptamine receptor 1A, (5-HT1A)
- Endocytosis
- Förster Resonance Energy Transfer, (FRET)
- G protein-coupled receptor
- G protein-coupled receptors, (GPCRs)
- GPCR kinases, (GRKs)
- Oligomeric complexes
- Receptor tyrosine kinase
- Resonance energy transfer
- Transactivation
- adrenoceptors, (AR)
- bioluminescence resonance energy transfer, (BRET)
- cannabinoid receptor 2, (CB2R)
- disintegrin and metalloproteinases, (ADAMs)
- epidermal growth factor receptor, (EGFR)
- epidermal growth factor, (EGF)
- fibroblast growth factor receptor, (FGFR)
- fluorescence correlation spectroscopy, (FCS)
- formyl peptide receptor, (FPR)
- free fatty acid, (FFA)
- heparin binding EGF, (Hb-EGF)
- hepatocyte growth factor, (HGF)
- human umbilical vein endothelial cells, (HUVECs)
- insulin growth factor receptor-1, (IGFR-1)
- insulin receptor, (IR)
- lysophosphatidic acid receptor 1, (LPA)
- matrix metalloproteinases, (MMPs)
- platelet-derived growth factor receptor, (PDGFR)
- proximity ligation assay, (PLA)
- reactive oxygen species, (ROS)
- receptor tyrosine kinases, (RTKs)
- sphingosine-1-phosphate receptor, (S1PR)
- tetrahydrocannabinol, (THC)
- total internal reflection fluorescence microscopy, (TIRF-M)
- vascular endothelial growth factor receptor 2, (VEGFR2)
- vascular endothelial growth factor, (VEGF)
- vasopressin 2 receptor, (V2R)
Collapse
Affiliation(s)
- Laura E. Kilpatrick
- Division of Bimolecular Sciences and Medicinal Chemistry, Biodiscovery Institute, School of Pharmacy, University of Nottingham, Nottingham, NG7 2RD, UK
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, NG7 2UH, 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, NG7 2UH, UK
| |
Collapse
|
16
|
White CW, Kilpatrick LE, Pfleger KDG, Hill SJ. A nanoluciferase biosensor to investigate endogenous chemokine secretion and receptor binding. iScience 2021; 24:102011. [PMID: 33490919 PMCID: PMC7809502 DOI: 10.1016/j.isci.2020.102011] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 12/10/2020] [Accepted: 12/28/2020] [Indexed: 11/30/2022] Open
Abstract
Secreted chemokines are critical mediators of cellular communication that elicit intracellular signaling by binding membrane-bound receptors. Here we demonstrate the development and use of a sensitive real-time approach to quantify secretion and receptor binding of native chemokines in live cells to better understand their molecular interactions and function. CRISPR/Cas9 genome editing was used to tag the chemokine CXCL12 with the nanoluciferase fragment HiBiT. CXCL12 secretion was subsequently monitored and quantified by luminescence output. Binding of tagged CXCL12 to either chemokine receptors or membrane glycosaminoglycans could be monitored due to the steric constraints of nanoluciferase complementation. Furthermore, binding of native CXCL12-HiBiT to AlexaFluor488-tagged CXCR4 chemokine receptors could also be distinguished from glycosaminoglycan binding and pharmacologically analyzed using BRET. These live cell approaches combine the sensitivity of nanoluciferase with CRISPR/Cas9 genome editing to detect, quantify, and monitor binding of low levels of native secreted proteins in real time.
Collapse
Affiliation(s)
- Carl W White
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, 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
| | - Laura E Kilpatrick
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK.,School of Pharmacy, Biodiscovery Institute, University of Nottingham, Nottingham, NG7 2RD, 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, Nottingham NG7 2UH, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| |
Collapse
|
17
|
Perpiñá-Viciano C, Işbilir A, Zarca A, Caspar B, Kilpatrick LE, Hill SJ, Smit MJ, Lohse MJ, Hoffmann C. Kinetic Analysis of the Early Signaling Steps of the Human Chemokine Receptor CXCR4. Mol Pharmacol 2020; 98:72-87. [PMID: 32474443 PMCID: PMC7330677 DOI: 10.1124/mol.119.118448] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 05/06/2020] [Indexed: 01/14/2023] Open
Abstract
G protein–coupled receptors (GPCRs) are biologic switches that transduce extracellular stimuli into intracellular responses in the cell. Temporally resolving GPCR transduction pathways is key to understanding how cell signaling occurs. Here, we investigate the kinetics and dynamics of the activation and early signaling steps of the CXC chemokine receptor (CXCR) 4 in response to its natural ligands CXC chemokine ligand (CXCL) 12 and macrophage migration inhibitory factor (MIF), using Förster resonance energy transfer–based approaches. We show that CXCR4 presents a multifaceted response to CXCL12, with receptor activation (≈0.6 seconds) followed by a rearrangement in the receptor/G protein complex (≈1 seconds), a slower dimer rearrangement (≈1.7 seconds), and prolonged G protein activation (≈4 seconds). In comparison, MIF distinctly modulates every step of the transduction pathway, indicating distinct activation mechanisms and reflecting the different pharmacological properties of these two ligands. Our study also indicates that CXCR4 exhibits some degree of ligand-independent activity, a relevant feature for drug development.
Collapse
Affiliation(s)
- Cristina Perpiñá-Viciano
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital Jena, University of Jena, Jena, Germany (C.P.-V., C.H.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.-V., A.I., M.J.L., C.H.); Max-Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Vrije Universiteit, Amsterdam, The Netherlands (A.Z., M.J.S.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, United Kingdom (B.C., L.E.K., S.J.H.); and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., L.E.K., S.J.H.)
| | - Ali Işbilir
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital Jena, University of Jena, Jena, Germany (C.P.-V., C.H.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.-V., A.I., M.J.L., C.H.); Max-Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Vrije Universiteit, Amsterdam, The Netherlands (A.Z., M.J.S.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, United Kingdom (B.C., L.E.K., S.J.H.); and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., L.E.K., S.J.H.)
| | - Aurélien Zarca
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital Jena, University of Jena, Jena, Germany (C.P.-V., C.H.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.-V., A.I., M.J.L., C.H.); Max-Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Vrije Universiteit, Amsterdam, The Netherlands (A.Z., M.J.S.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, United Kingdom (B.C., L.E.K., S.J.H.); and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., L.E.K., S.J.H.)
| | - Birgit Caspar
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital Jena, University of Jena, Jena, Germany (C.P.-V., C.H.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.-V., A.I., M.J.L., C.H.); Max-Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Vrije Universiteit, Amsterdam, The Netherlands (A.Z., M.J.S.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, United Kingdom (B.C., L.E.K., S.J.H.); and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., L.E.K., S.J.H.)
| | - Laura E Kilpatrick
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital Jena, University of Jena, Jena, Germany (C.P.-V., C.H.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.-V., A.I., M.J.L., C.H.); Max-Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Vrije Universiteit, Amsterdam, The Netherlands (A.Z., M.J.S.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, United Kingdom (B.C., L.E.K., S.J.H.); and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., L.E.K., S.J.H.)
| | - Stephen J Hill
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital Jena, University of Jena, Jena, Germany (C.P.-V., C.H.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.-V., A.I., M.J.L., C.H.); Max-Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Vrije Universiteit, Amsterdam, The Netherlands (A.Z., M.J.S.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, United Kingdom (B.C., L.E.K., S.J.H.); and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., L.E.K., S.J.H.)
| | - Martine J Smit
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital Jena, University of Jena, Jena, Germany (C.P.-V., C.H.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.-V., A.I., M.J.L., C.H.); Max-Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Vrije Universiteit, Amsterdam, The Netherlands (A.Z., M.J.S.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, United Kingdom (B.C., L.E.K., S.J.H.); and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., L.E.K., S.J.H.)
| | - Martin J Lohse
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital Jena, University of Jena, Jena, Germany (C.P.-V., C.H.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.-V., A.I., M.J.L., C.H.); Max-Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Vrije Universiteit, Amsterdam, The Netherlands (A.Z., M.J.S.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, United Kingdom (B.C., L.E.K., S.J.H.); and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., L.E.K., S.J.H.)
| | - Carsten Hoffmann
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital Jena, University of Jena, Jena, Germany (C.P.-V., C.H.); Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg, Germany (C.P.-V., A.I., M.J.L., C.H.); Max-Delbrück Center for Molecular Medicine, Berlin, Germany (A.I., M.J.L.); Amsterdam Institute for Molecules Medicines and Systems (AIMMS), Division of Medicinal Chemistry, Vrije Universiteit, Amsterdam, The Netherlands (A.Z., M.J.S.); Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Medical School, Queen's Medical Centre, Nottingham, United Kingdom (B.C., L.E.K., S.J.H.); and Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, United Kingdom (B.C., L.E.K., S.J.H.)
| |
Collapse
|
18
|
Comeo E, Kindon ND, Soave M, Stoddart LA, Kilpatrick LE, Scammells PJ, Hill SJ, Kellam B. Subtype-Selective Fluorescent Ligands as Pharmacological Research Tools for the Human Adenosine A 2A Receptor. J Med Chem 2020; 63:2656-2672. [PMID: 31887252 DOI: 10.1021/acs.jmedchem.9b01856] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Among class A G protein-coupled receptors (GPCR), the human adenosine A2A receptor (hA2AAR) remains an attractive drug target. However, translation of A2AAR ligands into the clinic has proved challenging and an improved understanding of A2AAR pharmacology could promote development of more efficacious therapies. Subtype-selective fluorescent probes would allow detailed real-time pharmacological investigations both in vitro and in vivo. In the present study, two families of fluorescent probes were designed around the known hA2AAR selective antagonist preladenant (SCH 420814). Both families of fluorescent antagonists retained affinity at the hA2AAR, selectivity over all other adenosine receptor subtypes and allowed clear visualization of specific receptor localization through confocal imaging. Furthermore, the Alexa Fluor 647-labeled conjugate allowed measurement of ligand binding affinities of unlabeled hA2AAR antagonists using a bioluminescence resonance energy transfer (NanoBRET) assay. The fluorescent ligands developed here can therefore be applied to a range of fluorescence-based techniques to further interrogate hA2AAR pharmacology and signaling.
Collapse
Affiliation(s)
- Eleonora Comeo
- Division of Biomolecular Sciences and Medicinal Chemistry, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K.,Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052 Australia
| | - Nicholas D Kindon
- Division of Biomolecular Sciences and Medicinal Chemistry, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| | - Mark Soave
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| | - Leigh A Stoddart
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| | - Laura E Kilpatrick
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| | - Peter J Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052 Australia
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| | - Barrie Kellam
- Division of Biomolecular Sciences and Medicinal Chemistry, School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, U.K.,Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands NG7 2UH, U.K
| |
Collapse
|
19
|
Peach CJ, Kilpatrick LE, Woolard J, Hill SJ. Comparison of the ligand-binding properties of fluorescent VEGF-A isoforms to VEGF receptor 2 in living cells and membrane preparations using NanoBRET. Br J Pharmacol 2019; 176:3220-3235. [PMID: 31162634 PMCID: PMC6692582 DOI: 10.1111/bph.14755] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 05/01/2019] [Accepted: 05/21/2019] [Indexed: 11/28/2022] Open
Abstract
Background and Purpose Vascular endothelial growth factor A (VEGF‐A) is a key mediator of angiogenesis. A striking feature of the binding of a fluorescent analogue of VEGF165a to nanoluciferase‐tagged VEGF receptor 2 (VEGFR2) in living cells is that the BRET signal is not sustained and declines over time. This may be secondary to receptor internalisation. Here, we have compared the binding of three fluorescent VEGF‐A isoforms to VEGFR2 in cells and isolated membrane preparations. Experimental Approach Ligand‐binding kinetics were monitored in both intact HEK293T cells and membranes (expressing nanoluciferase‐tagged VEGFR2) using BRET between tagged receptor and fluorescent analogues of VEGF165a, VEGF165b, and VEGF121a. VEGFR2 endocytosis in intact cells expressing VEGFR2 was monitored by following the appearance of fluorescent ligand‐associated receptors in intracellular endosomes using automated quantitative imaging. Key Results Quantitative analysis of the effect of fluorescent VEGF‐A isoforms on VEGFR2 endocytosis in cells demonstrated that they produce a rapid and potent translocation of ligand‐bound VEGFR2 into intracellular endosomes. NanoBRET can be used to monitor the kinetics of the binding of fluorescent VEGF‐A isoforms to VEGFR2. In isolated membrane preparations, ligand‐binding association curves were maintained for the duration of the 90‐min experiment. Measurement of the koff at pH 6.0 in membrane preparations indicated shorter ligand residence times than those obtained at pH 7.4. Conclusions and Implications These studies suggest that rapid VEGF‐A isoform‐induced receptor endocytosis shortens agonist residence times on the receptor (1/koff) as VEGFR2 moves from the plasma membrane to the intracellular endosomes.
Collapse
Affiliation(s)
- Chloe J Peach
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Laura E Kilpatrick
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, 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, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| |
Collapse
|
20
|
Abstract
The influence of drug-receptor binding kinetics has often been overlooked during the development of new therapeutics that target G protein-coupled receptors (GPCRs). Over the last decade there has been a growing understanding that an in-depth knowledge of binding kinetics at GPCRs is required to successfully target this class of proteins. Ligand binding to a GPCR is often not a simple single step process with ligand freely diffusing in solution. This review will discuss the experiments and equations that are commonly used to measure binding kinetics and how factors such as allosteric regulation, rebinding and ligand interaction with the plasma membrane may influence these measurements. We will then consider the molecular characteristics of a ligand and if these can be linked to association and dissociation rates.
Collapse
Affiliation(s)
- David A Sykes
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Leigh A Stoddart
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Laura E Kilpatrick
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK
| | - Stephen J Hill
- Cell Signalling and Pharmacology Research Group, Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK; Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands, UK.
| |
Collapse
|
21
|
Kilpatrick LE, Alcobia DC, White CW, Peach CJ, Glenn JR, Zimmerman K, Kondrashov A, Pfleger KDG, Ohana RF, Robers MB, Wood KV, Sloan EK, Woolard J, Hill SJ. Complex Formation between VEGFR2 and the β 2-Adrenoceptor. Cell Chem Biol 2019; 26:830-841.e9. [PMID: 30956148 PMCID: PMC6593180 DOI: 10.1016/j.chembiol.2019.02.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/30/2018] [Accepted: 02/24/2019] [Indexed: 12/26/2022]
Abstract
Vascular endothelial growth factor (VEGF) is an important mediator of endothelial cell proliferation and angiogenesis via its receptor VEGFR2. A common tumor associated with elevated VEGFR2 signaling is infantile hemangioma that is caused by a rapid proliferation of vascular endothelial cells. The current first-line treatment for infantile hemangioma is the β-adrenoceptor antagonist, propranolol, although its mechanism of action is not understood. Here we have used bioluminescence resonance energy transfer and VEGFR2 genetically tagged with NanoLuc luciferase to demonstrate that oligomeric complexes involving VEGFR2 and the β2-adrenoceptor can be generated in both cell membranes and intracellular endosomes. These complexes are induced by agonist treatment and retain their ability to couple to intracellular signaling proteins. Furthermore, coupling of β2-adrenoceptor to β-arrestin2 is prolonged by VEGFR2 activation. These data suggest that protein-protein interactions between VEGFR2, the β2-adrenoceptor, and β-arrestin2 may provide insight into their roles in health and disease.
Collapse
Affiliation(s)
- Laura E Kilpatrick
- Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Diana C Alcobia
- Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK; Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Melbourne, VIC 3052, Australia
| | - Carl W White
- Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, 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, Nedlands, Perth, WA 6009, Australia
| | - Chloe J Peach
- Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Jackie R Glenn
- Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | | | - Alexander Kondrashov
- Wolfson Centre for Stem Cells, Tissue Engineering & Modelling (STEM), Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Kevin D G Pfleger
- Harry Perkins Institute of Medical Research and Centre for Medical Research, The University of Western Australia, Nedlands, Perth, WA 6009, Australia; Dimerix Limited, Nedlands, Perth, WA 6009, Australia
| | | | | | | | - Erica K Sloan
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Melbourne, VIC 3052, Australia; Cousins Center for Neuroimmunology, Semel Institute for Neuroscience and Human Behavior, Jonsson Comprehensive Cancer Center, UCLA AIDS Institute, University of California, Los Angeles, CA 90095, USA; Division of Surgical Oncology, Peter MacCallum Cancer Centre, Victorian Comprehensive Cancer Centre, 305 Grattan Street, Melbourne, VIC 3000, Australia
| | - Jeanette Woolard
- Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK.
| | - Stephen J Hill
- Division of Physiology, Pharmacology & Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK.
| |
Collapse
|
22
|
Peach CJ, Kilpatrick LE, Woolard J, Hill SJ. Quantifying binding of VEGF‐A isoforms at VEGFR2 in membranes. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.679.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Chloe J Peach
- Cell Signalling Research GroupUniversity of NottinghamNottinghamUnited Kingdom
- Centre of Membrane Proteins and ReceptorsThe MidlandsUnited Kingdom
| | - Laura E Kilpatrick
- Cell Signalling Research GroupUniversity of NottinghamNottinghamUnited Kingdom
- Centre of Membrane Proteins and ReceptorsThe MidlandsUnited Kingdom
| | - Jeanette Woolard
- Cell Signalling Research GroupUniversity of NottinghamNottinghamUnited Kingdom
- Centre of Membrane Proteins and ReceptorsThe MidlandsUnited Kingdom
| | - Steve J Hill
- Cell Signalling Research GroupUniversity of NottinghamNottinghamUnited Kingdom
- Centre of Membrane Proteins and ReceptorsThe MidlandsUnited Kingdom
| |
Collapse
|
23
|
Peach CJ, Kilpatrick LE, Friedman-Ohana R, Zimmerman K, Robers MB, Wood KV, Woolard J, Hill SJ. Real-Time Ligand Binding of Fluorescent VEGF-A Isoforms that Discriminate between VEGFR2 and NRP1 in Living Cells. Cell Chem Biol 2018; 25:1208-1218.e5. [PMID: 30057299 PMCID: PMC6200776 DOI: 10.1016/j.chembiol.2018.06.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 05/23/2018] [Accepted: 06/29/2018] [Indexed: 12/20/2022]
Abstract
Fluorescent VEGF-A isoforms have been evaluated for their ability to discriminate between VEGFR2 and NRP1 in real-time ligand binding studies in live cells using BRET. To enable this, we synthesized single-site (N-terminal cysteine) labeled versions of VEGF165a, VEGF165b, and VEGF121a. These were used in combination with N-terminal NanoLuc-tagged VEGFR2 or NRP1 to evaluate the selectivity of VEGF isoforms for these two membrane proteins. All fluorescent VEGF-A isoforms displayed high affinity for VEGFR2. Only VEGF165a-TMR bound to NanoLuc-NRP1 with a similar high affinity (4.4 nM). Competition NRP1 binding experiments yielded a rank order of potency of VEGF165a > VEGF189a > VEGF145a. VEGF165b, VEGF-Ax, VEGF121a, and VEGF111a were unable to bind to NRP1. There were marked differences in the kinetic binding profiles of VEGF165a-TMR for NRP1 and VEGFR2. These data emphasize the importance of the kinetic aspects of ligand binding to VEGFR2 and its co-receptors in the dynamics of VEGF signaling. VEGF165a, VEGF121a, and VEGF165b were single-site labeled with tetramethylrhodamine NanoBRET quantified that VEGF-A isoforms have similar binding properties at VEGFR2 NRP1 expressed in live cells does not bind VEGF165b, VEGF121a, VEGF-Ax, or VEGF111a VEGFR2 and NRP1 have markedly distinct kinetic profiles binding VEGF165a-TMR
Collapse
Affiliation(s)
- Chloe J Peach
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Nottingham NG7 2UH, UK
| | - Laura E Kilpatrick
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Nottingham NG7 2UH, UK
| | | | - Kris Zimmerman
- Promega Corporation, 2800 Woods Hollow Road, Madison, WI 53711, USA
| | - Matthew B Robers
- Promega Corporation, 2800 Woods Hollow Road, Madison, WI 53711, USA
| | - Keith V Wood
- Promega Corporation, 2800 Woods Hollow Road, Madison, WI 53711, USA
| | - 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, University of Birmingham and University of Nottingham, Nottingham NG7 2UH, 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, University of Birmingham and University of Nottingham, Nottingham NG7 2UH, UK.
| |
Collapse
|
24
|
Peach CJ, Mignone VW, Arruda MA, Alcobia DC, Hill SJ, Kilpatrick LE, Woolard J. Molecular Pharmacology of VEGF-A Isoforms: Binding and Signalling at VEGFR2. Int J Mol Sci 2018; 19:E1264. [PMID: 29690653 PMCID: PMC5979509 DOI: 10.3390/ijms19041264] [Citation(s) in RCA: 249] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 04/14/2018] [Accepted: 04/16/2018] [Indexed: 02/07/2023] Open
Abstract
Vascular endothelial growth factor-A (VEGF-A) is a key mediator of angiogenesis, signalling via the class IV tyrosine kinase receptor family of VEGF Receptors (VEGFRs). Although VEGF-A ligands bind to both VEGFR1 and VEGFR2, they primarily signal via VEGFR2 leading to endothelial cell proliferation, survival, migration and vascular permeability. Distinct VEGF-A isoforms result from alternative splicing of the Vegfa gene at exon 8, resulting in VEGFxxxa or VEGFxxxb isoforms. Alternative splicing events at exons 5⁻7, in addition to recently identified posttranslational read-through events, produce VEGF-A isoforms that differ in their bioavailability and interaction with the co-receptor Neuropilin-1. This review explores the molecular pharmacology of VEGF-A isoforms at VEGFR2 in respect to ligand binding and downstream signalling. To understand how VEGF-A isoforms have distinct signalling despite similar affinities for VEGFR2, this review re-evaluates the typical classification of these isoforms relative to the prototypical, “pro-angiogenic” VEGF165a. We also examine the molecular mechanisms underpinning the regulation of VEGF-A isoform signalling and the importance of interactions with other membrane and extracellular matrix proteins. As approved therapeutics targeting the VEGF-A/VEGFR signalling axis largely lack long-term efficacy, understanding these isoform-specific mechanisms could aid future drug discovery efforts targeting VEGF receptor pharmacology.
Collapse
Affiliation(s)
- Chloe J Peach
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
| | - Viviane W Mignone
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
- CAPES-University of Nottingham Programme in Drug Discovery, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Maria Augusta Arruda
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
- CAPES-University of Nottingham Programme in Drug Discovery, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Diana C Alcobia
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
| | - Laura E Kilpatrick
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
| |
Collapse
|
25
|
Stoddart LA, Kilpatrick LE, Hill SJ. NanoBRET Approaches to Study Ligand Binding to GPCRs and RTKs. Trends Pharmacol Sci 2018; 39:136-147. [PMID: 29132917 DOI: 10.1016/j.tips.2017.10.006] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/12/2017] [Accepted: 10/17/2017] [Indexed: 12/30/2022]
Abstract
Recent advances in the development of fluorescent ligands for G-protein-coupled receptors (GPCRs) and receptor tyrosine kinase receptors (RTKs) have facilitated the study of these receptors in living cells. A limitation of these ligands is potential uptake into cells and increased nonspecific binding. However, this can largely be overcome by using proximity approaches, such as bioluminescence resonance energy transfer (BRET), which localise the signal (within 10nm) to the specific receptor target. The recent engineering of NanoLuc has resulted in a luciferase variant that is smaller and significantly brighter (up to tenfold) than existing variants. Here, we review the use of BRET from N-terminal NanoLuc-tagged GPCRs or a RTK to a receptor-bound fluorescent ligand to provide quantitative pharmacology of ligand-receptor interactions in living cells in real time.
Collapse
Affiliation(s)
- Leigh A Stoddart
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK; These authors contributed equally to this work
| | - Laura E Kilpatrick
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK; These authors contributed equally to this work
| | - 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, University of Birmingham and University of Nottingham, The Midlands, UK.
| |
Collapse
|
26
|
Singh S, Cooper S, Glenn JR, Beresford J, Percival LR, Tyndall JDA, Hill SJ, Kilpatrick LE, Vernall AJ. Synthesis of novel (benzimidazolyl)isoquinolinols and evaluation as adenosine A1 receptor tools. RSC Adv 2018; 8:16362-16369. [PMID: 35542203 PMCID: PMC9080270 DOI: 10.1039/c7ra13148h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 04/21/2018] [Indexed: 11/21/2022] Open
Abstract
G protein-coupled receptors (GPCRs) constitute the largest family of transmembrane receptors in eukaryotes. The adenosine A1 receptor (A1AR) is a class A GPCR that is of interest as a therapeutic target particularly in the treatment of cardiovascular disease and neuropathic pain. Increased knowledge of the role A1AR plays in mediating these pathophysiological processes will help realise the therapeutic potential of this receptor. There is a lack of enabling tools such as selective fluorescent probes to study A1AR, therefore we designed a series of (benzimidazolyl)isoquinolinols conjugated to a fluorescent dye (31–35, 42–43). An improved procedure for the synthesis of isoquinolinols from tetrahydroisoquinolinols via oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and atmospheric oxygen is reported. This synthetic method offers advantages over previous metal-based methods for the preparation of isoquinolinols and isoquinolines, which are important scaffolds found in many biologically active compounds and natural products. We report the first synthesis of the (benzimidazolyl)isoquinolinol compound class, however the fluorescent conjugates were not successful as A1AR fluorescent ligands. Mild, metal free aromatization of tetrahydroisoquinolinols. Synthesis of (benzimidazolyl)isoquinolinols.![]()
Collapse
Affiliation(s)
- Sameek Singh
- School of Pharmacy
- University of Otago
- Dunedin 9054
- New Zealand
| | - Samantha L. Cooper
- Physiology, Pharmacology and Neuroscience Division
- School of Life Sciences
- University of Nottingham
- Nottingham
- UK
| | - Jacqueline R. Glenn
- Physiology, Pharmacology and Neuroscience Division
- School of Life Sciences
- University of Nottingham
- Nottingham
- UK
| | - Jessica Beresford
- Physiology, Pharmacology and Neuroscience Division
- School of Life Sciences
- University of Nottingham
- Nottingham
- UK
| | - Lydia R. Percival
- Physiology, Pharmacology and Neuroscience Division
- School of Life Sciences
- University of Nottingham
- Nottingham
- UK
| | | | - Stephen J. Hill
- Physiology, Pharmacology and Neuroscience Division
- School of Life Sciences
- University of Nottingham
- Nottingham
- UK
| | - Laura E. Kilpatrick
- Physiology, Pharmacology and Neuroscience Division
- School of Life Sciences
- University of Nottingham
- Nottingham
- UK
| | | |
Collapse
|
27
|
Briddon SJ, Kilpatrick LE, Hill SJ. Studying GPCR Pharmacology in Membrane Microdomains: Fluorescence Correlation Spectroscopy Comes of Age. Trends Pharmacol Sci 2017; 39:158-174. [PMID: 29277246 DOI: 10.1016/j.tips.2017.11.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 11/13/2017] [Accepted: 11/14/2017] [Indexed: 12/17/2022]
Abstract
G protein-coupled receptors (GPCRs) are organised within the cell membrane into highly ordered macromolecular complexes along with other receptors and signalling proteins. Understanding how heterogeneity in these complexes affects the pharmacology and functional response of these receptors is crucial for developing new and more selective ligands. Fluorescence correlation spectroscopy (FCS) and related techniques such as photon counting histogram (PCH) analysis and image-based FCS can be used to interrogate the properties of GPCRs in these membrane microdomains, as well as their interaction with fluorescent ligands. FCS analyses fluorescence fluctuations within a small-defined excitation volume to yield information about their movement, concentration and molecular brightness (aggregation). These techniques can be used on live cells with single-molecule sensitivity and high spatial resolution. Once the preserve of specialist equipment, FCS techniques can now be applied using standard confocal microscopes. This review describes how FCS and related techniques have revealed novel insights into GPCR biology.
Collapse
Affiliation(s)
- Stephen J Briddon
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK; Centre for Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, UK
| | - Laura E Kilpatrick
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK; Centre for 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 for Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, The Midlands, UK.
| |
Collapse
|
28
|
Kilpatrick LE, Friedman-Ohana R, Alcobia DC, Riching K, Peach CJ, Wheal AJ, Briddon SJ, Robers MB, Zimmerman K, Machleidt T, Wood KV, Woolard J, Hill SJ. Real-time analysis of the binding of fluorescent VEGF 165a to VEGFR2 in living cells: Effect of receptor tyrosine kinase inhibitors and fate of internalized agonist-receptor complexes. Biochem Pharmacol 2017; 136:62-75. [PMID: 28392095 PMCID: PMC5457915 DOI: 10.1016/j.bcp.2017.04.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 04/04/2017] [Indexed: 01/01/2023]
Abstract
Vascular endothelial growth factor (VEGF) is an important mediator of angiogenesis. Here we have used a novel stoichiometric protein-labeling method to generate a fluorescent variant of VEGF (VEGF165a-TMR) labeled on a single cysteine within each protomer of the antiparallel VEGF homodimer. VEGF165a-TMR has then been used in conjunction with full length VEGFR2, tagged with the bioluminescent protein NanoLuc, to undertake a real time quantitative evaluation of VEGFR2 binding characteristics in living cells using bioluminescence resonance energy transfer (BRET). This provided quantitative information on VEGF-VEGFR2 interactions. At longer incubation times, VEGFR2 is internalized by VEGF165a-TMR into intracellular endosomes. This internalization can be prevented by the receptor tyrosine kinase inhibitors (RTKIs) cediranib, sorafenib, pazopanib or vandetanib. In the absence of RTKIs, the BRET signal is decreased over time as a consequence of the dissociation of agonist from the receptor in intracellular endosomes and recycling of VEGFR2 back to the plasma membrane.
Collapse
Affiliation(s)
- Laura E Kilpatrick
- Cell Signalling and Pharmacology Research Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | | | - Diana C Alcobia
- Cell Signalling and Pharmacology Research Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | | | - Chloe J Peach
- Cell Signalling and Pharmacology Research Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Amanda J Wheal
- Cell Signalling and Pharmacology Research Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Stephen J Briddon
- Cell Signalling and Pharmacology Research Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | | | | | | | | | - Jeanette Woolard
- Cell Signalling and Pharmacology Research Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom.
| | - Stephen J Hill
- Cell Signalling and Pharmacology Research Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom.
| |
Collapse
|
29
|
Stoddart LA, Kilpatrick LE, Briddon SJ, Hill SJ. Probing the pharmacology of G protein-coupled receptors with fluorescent ligands. Neuropharmacology 2015; 98:48-57. [PMID: 25979488 DOI: 10.1016/j.neuropharm.2015.04.033] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 04/23/2015] [Accepted: 04/29/2015] [Indexed: 01/01/2023]
Abstract
G protein-coupled receptors control a wide range of physiological processes and are the target for many clinically used drugs. Understanding the way in which receptors bind agonists and antagonists, their organisation in the membrane and their regulation after agonist binding are important properties which are key to developing new drugs. One way to achieve this knowledge is through the use of fluorescent ligands, which have been used to study the expression and function of receptors in endogenously expressing systems. Fluorescent ligands with appropriate imaging properties can be used in conjunction with confocal microscopy to investigate the regulation of receptors after activation. Alternatively, through the use of single molecule microscopy, they can probe the spatial organisation of receptors within the membrane. This review focuses on the techniques in which fluorescent ligands have been used and the novel aspects of G protein-coupled receptor pharmacology which have been uncovered. This article is part of the Special Issue entitled 'Fluorescent Tools in Neuropharmacology'.
Collapse
Affiliation(s)
- Leigh A Stoddart
- Cell Signalling Research Group, School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Laura E Kilpatrick
- Cell Signalling Research Group, School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Stephen J Briddon
- Cell Signalling Research Group, School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Stephen J Hill
- Cell Signalling Research Group, School of Life Sciences, University of Nottingham, Nottingham, UK
| |
Collapse
|
30
|
Kilpatrick LE, Humphrys LJ, Holliday ND. A G protein-coupled receptor dimer imaging assay reveals selectively modified pharmacology of neuropeptide Y Y1/Y5 receptor heterodimers. Mol Pharmacol 2015; 87:718-32. [PMID: 25637604 DOI: 10.1124/mol.114.095356] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The ability of G protein-coupled receptors (GPCRs) to form dimers, and particularly heterodimers, offers potential for targeted therapeutics with improved selectivity. However, studying dimer pharmacology is challenging, because of signaling cross-talk or because dimerization may often be transient in nature. Here we develop a system to isolate the pharmacology of precisely defined GPCR dimers, trapped by bimolecular fluorescence complementation (BiFC). Specific effects of agonist activation on such dimers are quantified using automated imaging and analysis of their internalization, controlled for by simultaneous assessment of endocytosis of one coexpressed protomer population. We applied this BiFC system to study example neuropeptide Y (NPY) Y1 receptor dimers. Incorporation of binding-site or phosphorylation-site mutations into just one protomer of a Y1/Y1 BiFC homodimer had no impact on efficient NPY-stimulated endocytosis, demonstrating that single-site agonist occupancy, and one phosphorylated monomer within this dimer, was sufficient. For two Y1 receptor heterodimer combinations (with the Y4 receptor or β2-adrenoceptor), agonist and antagonist pharmacology was explained by independent actions on the respective orthosteric binding sites. However, Y1/Y5 receptor BiFC dimers, compared with the constituent subtypes, were characterized by reduced potency and efficacy of Y5-selective peptide agonists, the inactivity of Y1-selective antagonists, and a change from surmountable to nonsurmountable antagonism for three unrelated Y5 antagonists. Thus, allosteric interactions between Y1 and Y5 receptors modify the pharmacology of the heterodimer, with implications for potential antiobesity agents that target centrally coexpressed Y1 and Y5 receptors to suppress appetite.
Collapse
Affiliation(s)
- Laura E Kilpatrick
- School of Life Sciences, University of Nottingham, The Medical School, Queen's Medical Centre, Nottingham, United Kingdom
| | - Laura J Humphrys
- School of Life Sciences, University of Nottingham, The Medical School, Queen's Medical Centre, Nottingham, United Kingdom
| | - Nicholas D Holliday
- School of Life Sciences, University of Nottingham, The Medical School, Queen's Medical Centre, Nottingham, United Kingdom
| |
Collapse
|
31
|
Corriden R, Kilpatrick LE, Kellam B, Briddon SJ, Hill SJ. Kinetic analysis of antagonist-occupied adenosine-A3 receptors within membrane microdomains of individual cells provides evidence of receptor dimerization and allosterism. FASEB J 2014; 28:4211-22. [PMID: 24970394 PMCID: PMC4202110 DOI: 10.1096/fj.13-247270] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
In our previous work, using a fluorescent adenosine-A3 receptor (A3AR) agonist and fluorescence correlation spectroscopy (FCS), we demonstrated high-affinity labeling of the active receptor (R*) conformation. In the current study, we used a fluorescent A3AR antagonist (CA200645) to study the binding characteristics of antagonist-occupied inactive receptor (R) conformations in membrane microdomains of individual cells. FCS analysis of CA200645-occupied A3ARs revealed 2 species, τD2 and τD3, that diffused at 2.29 ± 0.35 and 0.09 ± 0.03 μm(2)/s, respectively. FCS analysis of a green fluorescent protein (GFP)-tagged A3AR exhibited a single diffusing species (0.105 μm(2)/s). The binding of CA200645 to τD3 was antagonized by nanomolar concentrations of the A3 antagonist MRS 1220, but not by the agonist NECA (up to 300 nM), consistent with labeling of R. CA200645 normally dissociated slowly from the A3AR, but inclusion of xanthine amine congener (XAC) or VUF 5455 during washout markedly accelerated the reduction in the number of particles exhibiting τD3 characteristics. It is notable that this effect was accompanied by a significant increase in the number of particles with τD2 diffusion. These data show that FCS analysis of ligand-occupied receptors provides a unique means of monitoring ligand A3AR residence times that are significantly reduced as a consequence of allosteric interaction across the dimer interface
Collapse
Affiliation(s)
- Ross Corriden
- Institute of Cell Signalling, School of Life Sciences, Medical School, and
| | - Laura E Kilpatrick
- Institute of Cell Signalling, School of Life Sciences, Medical School, and
| | - Barrie Kellam
- School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Stephen J Briddon
- Institute of Cell Signalling, School of Life Sciences, Medical School, and
| | - Stephen J Hill
- Institute of Cell Signalling, School of Life Sciences, Medical School, and
| |
Collapse
|
32
|
Kilpatrick LE, Briddon SJ, Holliday ND. Fluorescence correlation spectroscopy, combined with bimolecular fluorescence complementation, reveals the effects of β-arrestin complexes and endocytic targeting on the membrane mobility of neuropeptide Y receptors. Biochim Biophys Acta 2012; 1823:1068-81. [PMID: 22487268 PMCID: PMC3793875 DOI: 10.1016/j.bbamcr.2012.03.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 02/29/2012] [Accepted: 03/01/2012] [Indexed: 01/22/2023]
Abstract
Fluorescence correlation spectroscopy (FCS) and photon counting histogram (PCH) analysis are powerful ways to study mobility and stoichiometry of G protein coupled receptor complexes, within microdomains of single living cells. However, relating these properties to molecular mechanisms can be challenging. We investigated the influence of β-arrestin adaptors and endocytosis mechanisms on plasma membrane diffusion and particle brightness of GFP-tagged neuropeptide Y (NPY) receptors. A novel GFP-based bimolecular fluorescence complementation (BiFC) system also identified Y1 receptor-β-arrestin complexes. Diffusion co-efficients (D) for Y1 and Y2-GFP receptors in HEK293 cell plasma membranes were 2.22 and 2.15 × 10− 9 cm2 s− 1 respectively. At a concentration which promoted only Y1 receptor endocytosis, NPY treatment reduced Y1-GFP motility (D 1.48 × 10− 9 cm2 s− 1), but did not alter diffusion characteristics of the Y2-GFP receptor. Agonist induced changes in Y1 receptor motility were inhibited by mutations (6A) which prevented β-arrestin recruitment and internalisation; conversely they became apparent in a Y2 receptor mutant with increased β-arrestin affinity. NPY treatment also increased Y1 receptor-GFP particle brightness, changes which indicated receptor clustering, and which were abolished by the 6A mutation. The importance of β-arrestin recruitment for these effects was illustrated by reduced lateral mobility (D 1.20–1.33 × 10− 9 cm2 s− 1) of Y1 receptor-β-arrestin BiFC complexes. Thus NPY-induced changes in Y receptor motility and brightness reflect early events surrounding arrestin dependent endocytosis at the plasma membrane, results supported by a novel combined BiFC/FCS approach to detect the underlying receptor-β-arrestin signalling complex.
Collapse
Affiliation(s)
- Laura E Kilpatrick
- Cell Signaling Research Group, School of Biomedical Sciences, University of Nottingham, the Medical School, Queen's Medical Centre, Nottingham, UK
| | | | | |
Collapse
|
33
|
Kilpatrick LE, Holliday ND. Dissecting the pharmacology of G protein-coupled receptor signaling complexes using bimolecular fluorescence complementation. Methods Mol Biol 2012; 897:109-38. [PMID: 22674163 DOI: 10.1007/978-1-61779-909-9_6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The affinity of G protein-coupled receptors (GPCRs) for particular ligands is altered by allosteric regulation with other proteins, for example signaling partners such as G proteins or β-arrestins, or multimeric receptor complexes. Studying the ways in which such interactions modulate pharmacology requires techniques that report these events at the molecular level. Options include bimolecular fluorescence complementation (BiFC), an imaging-based method that can directly demonstrate protein-protein association in living cells. Commonly used fluorescent proteins are split into two nonfluorescent halves, which then tag the protein partners under investigation. Interaction between the partners brings the complementary fragments together, allowing refolding and regeneration of the fluorescent protein to indicate that association has occurred. BiFC is irreversible and is not a real-time technique, yet the simplicity of its fluorescent signal holds key advantages for quantification and cellular localization of the resultant complexes.This review introduces general experimental considerations for using the BiFC approach, and describes specific protocols to develop a BiFC assay for GPCR-β-arrestin association, quantified using high content imaging and analysis. A further application of BiFC is to identify a particular protein-protein complex, thereby allowing investigation of its functional properties. This is illustrated in a protocol to quantify ligand-induced internalization of GPCR dimers of precise composition.
Collapse
Affiliation(s)
- Laura E Kilpatrick
- Cell Signalling Research Group, School of Biomedical Sciences, University of Nottingham, The Medical School, Nottingham, UK
| | | |
Collapse
|
34
|
Kilpatrick LE, Briddon SJ, Hill SJ, Holliday ND. Quantitative analysis of neuropeptide Y receptor association with beta-arrestin2 measured by bimolecular fluorescence complementation. Br J Pharmacol 2010; 160:892-906. [PMID: 20438572 PMCID: PMC2901518 DOI: 10.1111/j.1476-5381.2010.00676.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND AND PURPOSE beta-Arrestins are critical scaffold proteins that shape spatiotemporal signalling from seven transmembrane domain receptors (7TMRs). Here, we study the association between neuropeptide Y (NPY) receptors and beta-arrestin2, using bimolecular fluorescence complementation (BiFC) to directly report underlying protein-protein interactions. EXPERIMENTAL APPROACH Y1 receptors were tagged with a C-terminal fragment, Yc, of yellow fluorescent protein (YFP), and beta-arrestin2 fused with the complementary N-terminal fragment, Yn. After Y receptor-beta-arrestin association, YFP fragment refolding to regenerate fluorescence (BiFC) was examined by confocal microscopy in transfected HEK293 cells. Y receptor/beta-arrestin2 BiFC responses were also quantified by automated imaging and granularity analysis. KEY RESULTS NPY stimulation promoted association between Y1-Yc and beta-arrestin2-Yn, and the specific development of BiFC in intracellular compartments, eliminated when using non-interacting receptor and arrestin mutants. Responses developed irreversibly and were slower than for downstream Y1 receptor-YFP internalization, a consequence of delayed maturation and stability of complemented YFP. However, beta-arrestin2 BiFC measurements delivered appropriate ligand pharmacology for both Y1 and Y2 receptors, and demonstrated higher affinity of Y1 compared to Y2 receptors for beta-arrestin2. Receptor mutagenesis combined with beta-arrestin2 BiFC revealed that alternative arrangements of Ser/Thr residues in the Y1 receptor C tail could support beta-arrestin2 association, and that Y2 receptor-beta-arrestin2 interaction was enhanced by the intracellular loop mutation H155P. CONCLUSIONS AND IMPLICATIONS The BiFC approach quantifies Y receptor ligand pharmacology focused on the beta-arrestin2 pathway, and provides insight into mechanisms of beta-arrestin2 recruitment by activated and phosphorylated 7TMRs, at the level of protein-protein interaction.
Collapse
Affiliation(s)
- L E Kilpatrick
- Institute of Cell Signalling, School of Biomedical Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | | | | | | |
Collapse
|
35
|
Kilpatrick LE. World Vaccine Congress 2008. IDrugs 2008; 11:475-477. [PMID: 18600590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Laura E Kilpatrick
- McKenna Long & Aldridge LLP, 1900 K Street, NW, Washington DC 20006, USA.
| |
Collapse
|
36
|
Hannesschlager JR, Kilpatrick LE. Infocast End to End Preparedness for Pandemic Influenza. Opportunities for public-private collaboration. IDrugs 2007; 10:33-6. [PMID: 17187312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
|
37
|
Korchak HM, Corkey BE, Yaney GC, Kilpatrick LE. Negative regulation of ligand-initiated Ca(2+) uptake by PKC-beta II in differentiated HL60 cells. Am J Physiol Cell Physiol 2001; 281:C514-23. [PMID: 11443050 DOI: 10.1152/ajpcell.2001.281.2.c514] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In phagocytic cells, fMet-Leu-Phe triggers phosphoinositide remodeling, activation of protein kinase C (PKC), release of intracellular Ca(2+) and uptake of extracellular Ca(2+). Uptake of extracellular Ca(2+) can be triggered by store-operated Ca(2+) channels (SOCC) and via a receptor-operated nonselective cation channel(s). In neutrophilic HL60 cells, the PKC activator phorbol myristate acetate (PMA) activates multiple PKC isotypes, PKC-alpha, PKC-beta, and PKC-delta, and inhibits ligand-initiated mobilization of intracellular Ca(2+) and uptake of extracellular Ca(2+). Therefore PKC is a negative regulator at several points in Ca(2+) mobilization. In contrast, selective depletion of PKC-beta in HL60 cells by an antisense strategy enhanced fMet-Leu-Phe-initiated Ca(2+) uptake but not mobilization of intracellular Ca(2+). Thapsigargin-induced Ca(2+) uptake through SOCC was not affected by PKC-beta II depletion. Thus PKC-beta II is a selective negative regulator of Ca(2+) uptake but not release of intracellular Ca(2+) stores. PKC-beta II inhibits a receptor-operated cation or Ca(2+) channel, thus inhibiting ligand-initiated Ca(2+) uptake.
Collapse
Affiliation(s)
- H M Korchak
- Department of Pediatrics, University of Pennsylvania School of Medicine, The Joseph Stokes Jr. Research Institute of the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.
| | | | | | | |
Collapse
|
38
|
Korchak HM, Kilpatrick LE. Roles for beta II-protein kinase C and RACK1 in positive and negative signaling for superoxide anion generation in differentiated HL60 cells. J Biol Chem 2001; 276:8910-7. [PMID: 11120743 DOI: 10.1074/jbc.m008326200] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
beta-Protein kinase (PKC) is essential for ligand-initiated assembly of the NADPH oxidase for generation of superoxide anion (O(2)). Neutrophils and neutrophilic HL60 cells contain both betaI and betaII-PKC, isotypes that are derived by alternate splicing. betaI-PKC-positive and betaI-PKC null HL60 cells generated equivalent amounts of O(2) in response to fMet-Leu-Phe and phorbol myristate acetate. However, antisense depletion of betaII-PKC from betaI-PKC null cells inhibited ligand-initiated O(2) generation. fMet-Leu-Phe triggered association of a cytosolic NADPH oxidase component, p47(phox), with betaII-PKC but not with RACK1, a binding protein for betaII-PKC. Thus, RACK1 was not a component of the signaling complex for NADPH oxidase assembly. Inhibition of beta-PKC/RACK1 association by an inhibitory peptide or by antisense depletion of RACK1 enhanced O(2) generation. Therefore, betaII-PKC but not betaI-PKC is essential for activation of O(2) generation and plays a positive role in signaling for NADPH oxidase activation in association with p47(phox). In contrast, RACK1 is involved in negative signaling for O(2) generation. RACK1 binds to betaII-PKC but not with the p47(phox).betaII-PKC complex. RACK1 may divert betaII-PKC to other signaling pathways requiring beta-PKC for signal transduction. Alternatively, RACK1 may sequester betaII-PKC to down-regulate O(2) generation.
Collapse
Affiliation(s)
- H M Korchak
- Department of Pediatrics, University of Pennsylvania School of Medicine, The Joseph Stokes, Jr. Research Institute of the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.
| | | |
Collapse
|
39
|
Korchak HM, Kilpatrick LE. TNFalpha elicits association of PI 3-kinase with the p60TNFR and activation of PI 3-kinase in adherent neutrophils. Biochem Biophys Res Commun 2001; 281:651-6. [PMID: 11237707 DOI: 10.1006/bbrc.2001.4406] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tumor necrosis factor (TNFalpha) is an incomplete secretagogue in neutrophils and requires the engagement of beta integrins to trigger secretion of superoxide anion (O(-)(2)). The p60 TNF receptor (p60TNFR) is responsible for signal transduction for activation of O(-)(2) generation. Activation of TNFalpha-triggered O(-)(2) generation in neutrophils adherent to fibrinogen-coated surfaces involves the beta2 integrin receptor CD11b/CD18. Phosphoinositide 3-kinase (PI 3-kinase) is essential for activation of O(-)(2) generation; wortmannin, an inhibitor of PI 3-kinase, inhibited TNFalpha-elicited O(-)(2) generation. p60TNFR immunoprecipitated from neutrophils was associated with immunoreactivity to PI 3-kinase in adherent neutrophils exposed to TNFalpha, but not in TNFalpha-treated neutrophils in suspension. In addition, PI 3-kinase immunoprecipitated from TNFalpha-activated neutrophils showed enhanced activity in adherent but not in nonadherent neutrophils. These findings suggest that synergism between CD11b/CD18 and p60TNFR in the presence of TNFalpha is required to elicit assembly of a signaling complex involving association of p60TNFR with PI 3-kinase, activation of PI 3-kinase, and generation of O(-)(2).
Collapse
Affiliation(s)
- H M Korchak
- Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, 19104, USA
| | | |
Collapse
|
40
|
Kilpatrick LE, Song YH, Rossi MW, Korchak HM. Serine phosphorylation of p60 tumor necrosis factor receptor by PKC-delta in TNF-alpha-activated neutrophils. Am J Physiol Cell Physiol 2000; 279:C2011-8. [PMID: 11078718 DOI: 10.1152/ajpcell.2000.279.6.c2011] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Tumor necrosis factor-alpha (TNF-alpha) triggers degranulation and oxygen radical release in adherent neutrophils. The p60TNF receptor (p60TNFR) is responsible for proinflammatory signaling, and protein kinase C (PKC) is a candidate for the regulation of p60TNFR. Both TNF-alpha and the PKC-activator phorbol 12-myristate 13-acetate triggered phosphorylation of p60TNFR. Receptor phosphorylation was on both serine and threonine but not on tyrosine residues. The PKC-delta isotype is a candidate enzyme for serine phosphorylation of p60TNFR. Staurosporine and the PKC-delta inhibitor rottlerin inhibited TNF-alpha-triggered serine but not threonine phosphorylation. Serine phosphorylation was associated with receptor desensitization, as inhibition of PKC resulted in enhanced degranulation (elastase release). After neutrophil activation, PKC-delta was the only PKC isotype that associated with p60TNFR within the correct time frame for receptor phosphorylation. In vitro, only PKC-delta, but not the alpha-, betaI-, betaII-, or zeta-isotypes, was competent to phosphorylate the receptor, indicating that p60TNFR is a direct substrate for PKC-delta. These findings suggest a selective role for PKC-delta in negative regulation of the p60TNFR and of TNF-alpha-induced signaling.
Collapse
Affiliation(s)
- L E Kilpatrick
- Departments of Pediatrics and Biochemistry/Biophysics, University of Pennsylvania School of Medicine, and the Joseph Stokes Jr. Research Institute of the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.
| | | | | | | |
Collapse
|
41
|
Korchak HM, Rossi MW, Kilpatrick LE. Selective role for beta-protein kinase C in signaling for O-2 generation but not degranulation or adherence in differentiated HL60 cells. J Biol Chem 1998; 273:27292-9. [PMID: 9765254 DOI: 10.1074/jbc.273.42.27292] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A role for protein kinase C (PKC) isotypes is implicated in the activation of phagocytic cell functions. An antisense approach was used to selectively deplete beta-PKC, both betaI- and betaII-PKC, but not alpha-PKC, delta-PKC, or zeta-PKC in HL60 cells differentiated to a neutrophil-like phenotype (dHL60 cells). Depletion of beta-PKC in dHL60 cells elicited selective inhibition of O-2 generation triggered by fMet-Leu-Phe, immune complexes, or phorbol myristate acetate, an activator of PKC. In contrast, neither ligand-elicited beta-glucuronidase (azurophil granule) release nor adherence to fibronectin was inhibited by beta-PKC depletion. Ligand-induced phosphorylation of a subset of proteins was reduced in beta-PKC-depleted dHL60 cells. Phosphorylation of p47(phox) and translocation of p47(phox) to the membrane are essential for activation of the NADPH oxidase and generation of O-2. beta-PKC depletion had no effect on the level of p47(phox) in dHL60 cells but did significantly decrease ligand-induced phosphorylation of this protein. Furthermore, translocation of p47(phox) to the membrane in response to phorbol myristate acetate or fMet-Leu-Phe was reduced in beta-PKC-depleted cells. These results indicate that beta-PKC is essential for signaling for O-2 generation but not cell adherence or azurophil degranulation. Depletion of beta-PKC inhibited ligand-induced phosphorylation of p47(phox), translocation of p47(phox) to the membrane, and activation of O-2 generation.
Collapse
Affiliation(s)
- H M Korchak
- Departments of Pediatrics, University of Pennsylvania School of Medicine, The Joseph Stokes Jr. Research Institute of the Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA.
| | | | | |
Collapse
|
42
|
Kilpatrick LE, Jakabovics E, McCawley LJ, Kane LH, Korchak HM. Cromolyn inhibits assembly of the NADPH oxidase and superoxide anion generation by human neutrophils. J Immunol 1995; 154:3429-36. [PMID: 7897224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Early and late phase reactions have been observed in asthma; the late phase reaction is characterized by accumulation of inflammatory cells such as neutrophils. Activated neutrophils degranulate and assemble an active NADPH oxidase, which generates superoxide anion (O2-), reactions that have been implicated in lung tissue damage. Preincubation of neutrophils with the asthma drug cromolyn sodium selectively inhibited FMLP (10(-7) M) and PMA (0.1 microgram/ml) elicited O2- generation but not degranulation. To further characterize the mechanism of this inhibition we examined the effect of cromolyn on the NADPH oxidase complex and the signaling pathways for its assembly. Ca2+ mobilization and activation of protein kinase C have been implicated as signals for activation of the NADPH oxidase. Ca2+ mobilization triggered by FMLP was significantly decreased by 21.2% in cromolyn-treated cells. In contrast, cromolyn did not interfere with translocation or activity of protein kinase C. Membranes prepared from neutrophils stimulated with 0.5 microgram/ml PMA generated O2-, indicating assembly of an active NADPH oxidase; cromolyn did not inhibit this membrane-associated, preassembled oxidase. In contrast, preincubation of neutrophils with 100 microM cromolyn before addition of PMA decreased the capacity of the membranes to generate O2- by 57.3%. These results indicate that cromolyn inhibited the assembly of an active NADPH oxidase. The efficacy of cromolyn may be associated with inhibition of assembly of an active NADPH oxidase in the neutrophil and prevention of oxygen radical-induced tissue damage.
Collapse
Affiliation(s)
- L E Kilpatrick
- Department of Pediatrics, University of Pennsylvania School of Medicine, Children's Hospital of Philadelphia
| | | | | | | | | |
Collapse
|
43
|
Kilpatrick LE, Jakabovics E, McCawley LJ, Kane LH, Korchak HM. Cromolyn inhibits assembly of the NADPH oxidase and superoxide anion generation by human neutrophils. The Journal of Immunology 1995. [DOI: 10.4049/jimmunol.154.7.3429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Early and late phase reactions have been observed in asthma; the late phase reaction is characterized by accumulation of inflammatory cells such as neutrophils. Activated neutrophils degranulate and assemble an active NADPH oxidase, which generates superoxide anion (O2-), reactions that have been implicated in lung tissue damage. Preincubation of neutrophils with the asthma drug cromolyn sodium selectively inhibited FMLP (10(-7) M) and PMA (0.1 microgram/ml) elicited O2- generation but not degranulation. To further characterize the mechanism of this inhibition we examined the effect of cromolyn on the NADPH oxidase complex and the signaling pathways for its assembly. Ca2+ mobilization and activation of protein kinase C have been implicated as signals for activation of the NADPH oxidase. Ca2+ mobilization triggered by FMLP was significantly decreased by 21.2% in cromolyn-treated cells. In contrast, cromolyn did not interfere with translocation or activity of protein kinase C. Membranes prepared from neutrophils stimulated with 0.5 microgram/ml PMA generated O2-, indicating assembly of an active NADPH oxidase; cromolyn did not inhibit this membrane-associated, preassembled oxidase. In contrast, preincubation of neutrophils with 100 microM cromolyn before addition of PMA decreased the capacity of the membranes to generate O2- by 57.3%. These results indicate that cromolyn inhibited the assembly of an active NADPH oxidase. The efficacy of cromolyn may be associated with inhibition of assembly of an active NADPH oxidase in the neutrophil and prevention of oxygen radical-induced tissue damage.
Collapse
Affiliation(s)
- L E Kilpatrick
- Department of Pediatrics, University of Pennsylvania School of Medicine, Children's Hospital of Philadelphia
| | - E Jakabovics
- Department of Pediatrics, University of Pennsylvania School of Medicine, Children's Hospital of Philadelphia
| | - L J McCawley
- Department of Pediatrics, University of Pennsylvania School of Medicine, Children's Hospital of Philadelphia
| | - L H Kane
- Department of Pediatrics, University of Pennsylvania School of Medicine, Children's Hospital of Philadelphia
| | - H M Korchak
- Department of Pediatrics, University of Pennsylvania School of Medicine, Children's Hospital of Philadelphia
| |
Collapse
|
44
|
Abstract
The administration of a sublethal dose of endotoxin (LPS) followed one hour later by a low dose of aspirin (LPS + ASA) to fasted rats leads to biochemical perturbations similar to Reye's syndrome. In this study hepatic energy metabolism was assessed in freeze-clamped liver samples (12 hours posttreatment) obtained from (250 to 300 g Sprague-Dawley) rats. The administration of aspirin alone to fasted rats did not significantly alter the hepatic levels of adenine nucleotides, total ketones, or acyl-CoA thioesters as compared to controls. In contrast, in both LPS and LPS + ASA samples, there were declines in ATP/ADP ratio (P less than .005), total ketones (P less than .001) and acetyl CoA (P less than .005) compared to their respective controls. A striking alteration in acyl-CoA thioesters was observed in LPS + ASA-treated animals. Unlike control, aspirin, or LPS-treated animals, LPS + ASA-treated animals accumulated relatively large amounts of unusual CoA esters, including propionyl-CoA, (iso)butyryl-CoA, beta-methylcrotonyl-CoA, and isovaleryl-CoA, metabolites of the branch chain amino acid and odd-chain fatty acid oxidation pathways. The acyl-CoA profile is similar to that obtained in patients with Reye's syndrome. Like human patients with Reye's syndrome, these rats showed hyperammonemia, compromised fatty acid oxidation, and accumulation of branched chain amino acid oxidation metabolites. Accumulation of these intermediates with LPS + ASA is a possible mechanism for the potentiation of Reye's syndrome by aspirin. These findings provide biochemical evidence that sublethal doses of LPS + ASA administered to fasted rats produces an animal model of Reye's syndrome.
Collapse
Affiliation(s)
- L E Kilpatrick
- Department of Pediatrics, University of Pennsylvania Medical School, Children's Hospital, Philadelphia 19104
| | | | | | | |
Collapse
|