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Tóth AD, Turu G, Hunyady L. Functional consequences of spatial, temporal and ligand bias of G protein-coupled receptors. Nat Rev Nephrol 2024:10.1038/s41581-024-00869-3. [PMID: 39039165 DOI: 10.1038/s41581-024-00869-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2024] [Indexed: 07/24/2024]
Abstract
G protein-coupled receptors (GPCRs) regulate every aspect of kidney function by mediating the effects of various endogenous and exogenous substances. A key concept in GPCR function is biased signalling, whereby certain ligands may selectively activate specific pathways within the receptor's signalling repertoire. For example, different agonists may induce biased signalling by stabilizing distinct active receptor conformations - a concept that is supported by advances in structural biology. However, the processes underlying functional selectivity in receptor signalling are extremely complex, involving differences in subcellular compartmentalization and signalling dynamics. Importantly, the molecular mechanisms of spatiotemporal bias, particularly its connection to ligand binding kinetics, have been detailed for GPCRs critical to kidney function, such as the AT1 angiotensin receptor (AT1R), V2 vasopressin receptor (V2R) and the parathyroid hormone 1 receptor (PTH1R). This expanding insight into the multifaceted nature of biased signalling paves the way for innovative strategies for targeting GPCR functions; the development of novel biased agonists may represent advanced pharmacotherapeutic approaches to the treatment of kidney diseases and related systemic conditions, such as hypertension, diabetes and heart failure.
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Affiliation(s)
- András D Tóth
- Institute of Molecular Life Sciences, Centre of Excellence of the Hungarian Academy of Sciences, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary
- Department of Internal Medicine and Haematology, Semmelweis University, Budapest, Hungary
| | - Gábor Turu
- Institute of Molecular Life Sciences, Centre of Excellence of the Hungarian Academy of Sciences, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - László Hunyady
- Institute of Molecular Life Sciences, Centre of Excellence of the Hungarian Academy of Sciences, HUN-REN Research Centre for Natural Sciences, Budapest, Hungary.
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary.
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2
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Byambaragchaa M, Park SH, Kim SG, Shin MG, Kim SK, Park MH, Kang MH, Min KS. Stable Production of a Recombinant Single-Chain Eel Follicle-Stimulating Hormone Analog in CHO DG44 Cells. Int J Mol Sci 2024; 25:7282. [PMID: 39000389 PMCID: PMC11242883 DOI: 10.3390/ijms25137282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 06/28/2024] [Accepted: 06/29/2024] [Indexed: 07/16/2024] Open
Abstract
This study aimed to produce single-chain recombinant Anguillid eel follicle-stimulating hormone (rec-eel FSH) analogs with high activity in Cricetulus griseus ovary DG44 (CHO DG44) cells. We recently reported that an O-linked glycosylated carboxyl-terminal peptide (CTP) of the equine chorionic gonadotropin (eCG) β-subunit contributes to high activity and time-dependent secretion in mammalian cells. We constructed a mutant (FSH-M), in which a linker including the eCG β-subunit CTP region (amino acids 115-149) was inserted between the β-subunit and α-subunit of wild-type single-chain eel FSH (FSH-wt). Plasmids containing eel FSH-wt and eel FSH-M were transfected into CHO DG44 cells, and single cells expressing each protein were isolated from 10 and 7 clones. Secretion increased gradually during the cultivation period and peaked at 4000-5000 ng/mL on day 9. The molecular weight of eel FSH-wt was 34-40 kDa, whereas that of eel FSH-M increased substantially, with two bands at 39-46 kDa. Treatment with PNGase F to remove the N glycosylation sites decreased the molecular weight remarkably to approximately 8 kDa. The EC50 value and maximal responsiveness of eel FSH-M were approximately 1.23- and 1.06-fold higher than those of eel FSH-wt, indicating that the mutant showed slightly higher biological activity. Phosphorylated extracellular-regulated kinase (pERK1/2) activation exhibited a sharp peak at 5 min, followed by a rapid decline. These findings indicate that the new rec-eel FSH molecule with the eCG β-subunit CTP linker shows potent activity and could be produced in massive quantities using the stable CHO DG44 cell system.
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Affiliation(s)
- Munkhzaya Byambaragchaa
- Carbon-Neutral Resources Research Center, Hankyong National University, Anseong 17579, Republic of Korea;
- Institute of Genetic Engineering, Hankyong National University, Anseong 17579, Republic of Korea
| | - Sei Hyen Park
- Graduate School of Animal Biosciences, Hankyong National University, Anseong 17579, Republic of Korea; (S.H.P.); (S.-G.K.)
| | - Sang-Gwon Kim
- Graduate School of Animal Biosciences, Hankyong National University, Anseong 17579, Republic of Korea; (S.H.P.); (S.-G.K.)
| | - Min Gyu Shin
- Aquaculture Research Division, National Institute of Fisheries Science, Busan 46083, Republic of Korea; (M.G.S.); (S.-K.K.)
| | - Shin-Kwon Kim
- Aquaculture Research Division, National Institute of Fisheries Science, Busan 46083, Republic of Korea; (M.G.S.); (S.-K.K.)
| | | | - Myung-Hwa Kang
- Department of Food Science and Nutrition, Hoseo University, Asan 31499, Republic of Korea;
| | - Kwan-Sik Min
- Carbon-Neutral Resources Research Center, Hankyong National University, Anseong 17579, Republic of Korea;
- Institute of Genetic Engineering, Hankyong National University, Anseong 17579, Republic of Korea
- Division of Animal BioScience, School of Animal Life Convergence Sciences, Institute of Genetic Engineering, Hankyong National University, Anseong 17579, Republic of Korea
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3
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Gurevich VV, Gurevich EV. GPCR-dependent and -independent arrestin signaling. Trends Pharmacol Sci 2024; 45:639-650. [PMID: 38906769 PMCID: PMC11227395 DOI: 10.1016/j.tips.2024.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 05/15/2024] [Accepted: 05/18/2024] [Indexed: 06/23/2024]
Abstract
Biological activity of free arrestins is often overlooked. Based on available data, we compare arrestin-mediated signaling that requires and does not require binding to G-protein-coupled receptors (GPCRs). Receptor-bound arrestins activate ERK1/2, Src, and focal adhesion kinase (FAK). Yet, arrestin-3 regulation of Src family member Fgr does not appear to involve receptors. Free arrestin-3 facilitates the activation of JNK family kinases, preferentially binds E3 ubiquitin ligases Mdm2 and parkin, and facilitates parkin-dependent mitophagy. The binding of arrestins to microtubules and calmodulin and their function in focal adhesion disassembly and apoptosis also do not involve receptors. Biased GPCR ligands and the phosphorylation barcode can only affect receptor-dependent arrestin signaling. Thus, elucidation of receptor dependence or independence of arrestin functions has important scientific and therapeutic implications.
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Affiliation(s)
- Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN 27232, USA.
| | - Eugenia V Gurevich
- Department of Pharmacology, Vanderbilt University, Nashville, TN 27232, USA
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4
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Byambaragchaa M, Park SH, Kim SG, Shin MG, Kim SK, Hur SP, Park MH, Kang MH, Min KS. Stable Production of a Tethered Recombinant Eel Luteinizing Hormone Analog with High Potency in CHO DG44 Cells. Curr Issues Mol Biol 2024; 46:6085-6099. [PMID: 38921034 PMCID: PMC11202772 DOI: 10.3390/cimb46060363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 06/08/2024] [Accepted: 06/12/2024] [Indexed: 06/27/2024] Open
Abstract
We produced a recombinant eel luteinizing hormone (rec-eel LH) analog with high potency in Chinese hamster ovary DG44 (CHO DG44) cells. The tethered eel LH mutant (LH-M), which had a linker comprising the equine chorionic gonadotropin (eLH/CG) β-subunit carboxyl-terminal peptide (CTP) region (amino acids 115 to 149), was inserted between the β-subunit and α-subunit of wild-type tethered eel LH (LH-wt). Monoclonal cells transfected with the tethered eel LH-wt and eel LH-M plasmids were isolated from five to nine clones of CHO DG44 cells, respectively. The secreted quantities abruptly increased on day 3, with peak levels of 5000-7500 ng/mL on day 9. The molecular weight of tethered rec-eel LH-wt was 32-36 kDa, while that of tethered rec-eel LH-M increased to approximately 38-44 kDa, indicating the detection of two bands. Treatment with the peptide N-glycanase F decreased the molecular weight by approximately 8 kDa. The oligosaccharides at the eCG β-subunit O-linked glycosylation sites were appropriately modified post-translation. The EC50 value and maximal responsiveness of eel LH-M increased by approximately 2.90- and 1.29-fold, respectively, indicating that the mutant exhibited more potent biological activity than eel LH-wt. Phosphorylated extracellular regulated kinase (pERK1/2) activation resulted in a sharp peak 5 min after agonist treatment, with a rapid decrease thereafter. These results indicate that the new tethered rec-eel LH analog had more potent activity in cAMP response than the tethered eel LH-wt in vitro. Taken together, this new eel LH analog can be produced in large quantities using a stable CHO DG44 cell system.
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Affiliation(s)
- Munkhzaya Byambaragchaa
- Carbon-Neutral Resources Research Center, Hankyong National University, Anseong 17579, Republic of Korea; (M.B.); (M.-H.P.)
| | - Sei Hyen Park
- Graduate School of Animal Biosciences, Hankyong National University, Anseong 17579, Republic of Korea;
| | - Sang-Gwon Kim
- Graduate School of Animal Biosciences, Hankyong National University, Anseong 17579, Republic of Korea;
| | - Min Gyu Shin
- Aquaculture Research Division, National Institute of Fisheries Science, Busan 46083, Republic of Korea (M.G.S.); (S.-K.K.)
| | - Shin-Kwon Kim
- Aquaculture Research Division, National Institute of Fisheries Science, Busan 46083, Republic of Korea (M.G.S.); (S.-K.K.)
| | - Sung-Pyo Hur
- Department of Marine Life Science, Jeju National University, Jeju 63243, Republic of Korea;
| | - Myung-Hum Park
- Carbon-Neutral Resources Research Center, Hankyong National University, Anseong 17579, Republic of Korea; (M.B.); (M.-H.P.)
- Graduate School of Animal Biosciences, Hankyong National University, Anseong 17579, Republic of Korea;
| | - Myung-Hwa Kang
- Department of Food Science and Nutrition, Hoseo University, Asan 31499, Republic of Korea;
| | - Kwan-Sik Min
- Carbon-Neutral Resources Research Center, Hankyong National University, Anseong 17579, Republic of Korea; (M.B.); (M.-H.P.)
- Graduate School of Animal Biosciences, Hankyong National University, Anseong 17579, Republic of Korea;
- Division of Animal BioScience, School of Animal Life Convergence Sciences, Institute of Genetic Engineering, Hankyong National University, Anseong 17579, Republic of Korea
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5
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Gurevich VV. Arrestins: A Small Family of Multi-Functional Proteins. Int J Mol Sci 2024; 25:6284. [PMID: 38892473 PMCID: PMC11173308 DOI: 10.3390/ijms25116284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 05/24/2024] [Accepted: 05/31/2024] [Indexed: 06/21/2024] Open
Abstract
The first member of the arrestin family, visual arrestin-1, was discovered in the late 1970s. Later, the other three mammalian subtypes were identified and cloned. The first described function was regulation of G protein-coupled receptor (GPCR) signaling: arrestins bind active phosphorylated GPCRs, blocking their coupling to G proteins. It was later discovered that receptor-bound and free arrestins interact with numerous proteins, regulating GPCR trafficking and various signaling pathways, including those that determine cell fate. Arrestins have no enzymatic activity; they function by organizing multi-protein complexes and localizing their interaction partners to particular cellular compartments. Today we understand the molecular mechanism of arrestin interactions with GPCRs better than the mechanisms underlying other functions. However, even limited knowledge enabled the construction of signaling-biased arrestin mutants and extraction of biologically active monofunctional peptides from these multifunctional proteins. Manipulation of cellular signaling with arrestin-based tools has research and likely therapeutic potential: re-engineered proteins and their parts can produce effects that conventional small-molecule drugs cannot.
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6
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Manning JJ, Finlay DB, Glass M. GPCR kinase subtype requirements for arrestin-2 and -3 translocation to the cannabinoid CB 1 receptor and the consequences on G protein signalling. Biochem Pharmacol 2024; 224:116190. [PMID: 38604257 DOI: 10.1016/j.bcp.2024.116190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 04/13/2024]
Abstract
Arrestins are key negative regulators of G Protein-Coupled Receptors (GPCRs) through mediation of G protein desensitisation and receptor internalisation. Arrestins can also contribute to signal transduction by scaffolding downstream signalling effectors for activation. GPCR kinase (GRK) enzymes phosphorylate the intracellular C-terminal domain, or intracellular loop regions of GPCRs to promote arrestin interaction. There are seven different GRK subtypes, which may uniquely phosphorylate the C-terminal tail in a type of 'phosphorylation barcode,' potentially differentially contributing to arrestin translocation and arrestin-dependent signalling. Such contributions may be exploited to develop arrestin-biased ligands. Here, we examine the effect of different GRK subtypes on the ability to promote translocation of arrestin-2 and arrestin-3 to the cannabinoid CB1 receptor (CB1) with a range of ligands. We find that most GRK subtypes (including visual GRK1) can enhance arrestin-2 and -3 translocation to CB1, and that GRK-dependent changes in arrestin-2 and arrestin-3 translocation were broadly shared for most agonists tested. GRK2/3 generally enhanced arrestin translocation more than the other GRK subtypes, with some small differences between ligands. We also explore the interplay between G protein activity and GRK2/3-dependent arrestin translocation, highlighting that high-efficacy G protein agonists will cause GRK2/3 dependent arrestin translocation. This study supports the hypothesis that arrestin-biased ligands for CB1 must engage GRK5/6 rather than GRK2/3, and G protein-biased ligands must have inherently low efficacy.
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Affiliation(s)
- Jamie J Manning
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - David B Finlay
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Michelle Glass
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.
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7
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Khan S, Raghuram V, Chen L, Chou CL, Yang CR, Khundmiri SJ, Knepper MA. Vasopressin V2 receptor, tolvaptan, and ERK1/2 phosphorylation in the renal collecting duct. Am J Physiol Renal Physiol 2024; 326:F57-F68. [PMID: 37916285 PMCID: PMC10812694 DOI: 10.1152/ajprenal.00124.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 10/23/2023] [Accepted: 10/23/2023] [Indexed: 11/03/2023] Open
Abstract
Tolvaptan, a vasopressin antagonist selective for the V2-subtype vasopressin receptor (V2R), is widely used in the treatment of hyponatremia and autosomal-dominant polycystic kidney disease (ADPKD). Its effects on signaling in collecting duct cells have not been fully characterized. Here, we perform RNA-seq in a collecting duct cell line (mpkCCD). The data show that tolvaptan inhibits the expression of mRNAs that were previously shown to be increased in response to vasopressin including aquaporin-2, but also reveals mRNA changes that were not readily predictable and suggest off-target actions of tolvaptan. One such action is activation of the MAPK kinase (ERK1/ERK2) pathway. Prior studies have shown that ERK1/ERK2 activation is essential in the regulation of a variety of cellular and physiological processes and can be associated with cell proliferation. In immunoblotting experiments, we demonstrated that ERK1/ERK2 phosphorylation in mpkCCD cells was significantly reduced by vasopressin, in contrast to the increases seen in non-collecting-duct cells overexpressing V2R in prior studies. We also found that tolvaptan has a strong effect to increase ERK1/ERK2 phosphorylation in the presence of vasopressin and that tolvaptan's effect to increase ERK1/ERK2 phosphorylation is absent in mpkCCD cells in which both protein kinase A (PKA)-catalytic subunits have been deleted. Thus, it appears that the tolvaptan effect to increase ERK activation is PKA-dependent and is not due to an off-target effect of tolvaptan. We conclude that in cells expressing V2R at endogenous levels: 1) vasopressin decreases ERK1/ERK2 activation; 2) in the presence of vasopressin, tolvaptan increases ERK1/ERK2 activation; and 3) these effects are PKA-dependent.NEW & NOTEWORTHY Vasopressin is a key hormone that regulates the function of the collecting duct of the kidney. ERK1 and ERK2 are enzymes that play key roles in physiological regulation in all cells. The authors used collecting duct cell cultures to investigate the effects of vasopressin and the vasopressin receptor antagonist tolvaptan on ERK1 and ERK2 phosphorylation and activation.
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Affiliation(s)
- Shaza Khan
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
- Department of Physiology and Biophysics, College of Medicine, Howard University, Washington, District of Columbia, United States
| | - Viswanathan Raghuram
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Lihe Chen
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Chung-Lin Chou
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Chin-Rang Yang
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Syed J Khundmiri
- Department of Physiology and Biophysics, College of Medicine, Howard University, Washington, District of Columbia, United States
| | - Mark A Knepper
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States
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Guillien M, Mouhand A, Sagar A, Fournet A, Allemand F, Pereira GAN, Thureau A, Bernadó P, Banères JL, Sibille N. Phosphorylation motif dictates GPCR C-terminal domain conformation and arrestin interaction. Structure 2023; 31:1394-1406.e7. [PMID: 37669668 DOI: 10.1016/j.str.2023.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 07/07/2023] [Accepted: 08/09/2023] [Indexed: 09/07/2023]
Abstract
Arrestin-dependent G protein-coupled receptor (GPCR) signaling pathway is regulated by the phosphorylation state of GPCR's C-terminal domain, but the molecular bases of arrestin:receptor interaction are to be further illuminated. Here we investigated the impact of phosphorylation on the conformational features of the C-terminal region from three rhodopsin-like GPCRs, the vasopressin V2 receptor (V2R), the growth hormone secretagogue or ghrelin receptor type 1a (GHSR), and the β2-adernergic receptor (β2AR). Using phosphomimetic variants, we identified pre-formed secondary structure elements, or short linear motifs (SLiMs), that undergo specific conformational transitions upon phosphorylation. Of importance, such conformational transitions appear to favor arrestin-2 binding. Hence, our results suggest a model in which the phosphorylation-dependent structuration of the GPCR C-terminal regions would modulate arrestin binding and therefore signaling outcomes in arrestin-dependent pathways.
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Affiliation(s)
- Myriam Guillien
- Centre de Biologie Structurale (CBS), CNRS, University Montpellier, Inserm, Montpellier, France
| | - Assia Mouhand
- Centre de Biologie Structurale (CBS), CNRS, University Montpellier, Inserm, Montpellier, France
| | - Amin Sagar
- Centre de Biologie Structurale (CBS), CNRS, University Montpellier, Inserm, Montpellier, France
| | - Aurélie Fournet
- Centre de Biologie Structurale (CBS), CNRS, University Montpellier, Inserm, Montpellier, France
| | - Frédéric Allemand
- Centre de Biologie Structurale (CBS), CNRS, University Montpellier, Inserm, Montpellier, France
| | - Glaécia A N Pereira
- Institut des Biomolécules Max Mousseron (IBMM), UMR-5247, University Montpellier, CNRS, ENSCM, Montpellier, France
| | - Aurélien Thureau
- HélioBio Section, Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin BP 48, 91190 Gif-sur-Yvette, France
| | - Pau Bernadó
- Centre de Biologie Structurale (CBS), CNRS, University Montpellier, Inserm, Montpellier, France
| | - Jean-Louis Banères
- Institut des Biomolécules Max Mousseron (IBMM), UMR-5247, University Montpellier, CNRS, ENSCM, Montpellier, France
| | - Nathalie Sibille
- Centre de Biologie Structurale (CBS), CNRS, University Montpellier, Inserm, Montpellier, France.
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9
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Liu H, Acharya S, Sudan SK, Hu L, Wu C, Cao Y, Li H, Zhang X. Comparative study of the molecular mechanisms underlying the G protein and β-arrestin-dependent pathways that lead to ERKs activation upon stimulation by dopamine D 2 receptor. FEBS J 2023; 290:5204-5233. [PMID: 37531324 DOI: 10.1111/febs.16921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 06/09/2023] [Accepted: 08/01/2023] [Indexed: 08/04/2023]
Abstract
Dopamine D2 receptor (D2 R) has been shown to activate extracellular signal-regulated kinases (ERKs) via distinct pathways dependent on either G-protein or β-arrestin. However, there has not been a systematic study of the regulatory process of D2 R-mediated ERKs activation by G protein- versus β-arrestin-dependent signaling since D2 R stimulation of ERKs reflects the simultaneous action of both pathways. Here, we investigated that differential regulation of D2 R-mediated ERKs activation via these two pathways. Our results showed that G protein-dependent ERKs activation was transient, rapid, reached maximum level at around 2 min, and importantly, the activated ERKs were entirely confined to the cytoplasm. In contrast, β-arrestin-dependent ERKs activation was more sustained, slower, reached maximum level at around 10 min, and phosphorylated ERKs translocated into the nucleus. Src was found to be commonly involved in both the G protein- and β-arrestin-dependent pathway-mediated ERKs activation. Pertussis toxin Gi/o inhibitor, GRK2-CT, AG1478 epidermal growth factor receptor inhibitor, and wortmannin phosphoinositide 3-kinase inhibitor all blocked G protein-dependent ERKs activation. In contrast, GRK2 and β-Arr2 played a main role in β-arrestin-dependent ERKs activation. Receptor endocytosis showed minimal effect on the activation of ERKs mediated by both pathways. Furthermore, we found that the formation of a complex composed of phospho-ERKs, β-Arr2, and importinβ1 promoted the nuclear translocation of activated ERKs. The differential regulation of various cellular components, as well as temporal and spatial patterns of ERKs activation via these two pathways, suggest the existence of distinct physiological outcomes.
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Affiliation(s)
- Haiping Liu
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, China
| | - Srijan Acharya
- Mitchell Cancer Institute, School of Medicine, University of South Alabama, Mobile, AL, USA
| | - Sarabjeet Kour Sudan
- Mitchell Cancer Institute, School of Medicine, University of South Alabama, Mobile, AL, USA
| | - Li Hu
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, China
| | - Chengyan Wu
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, China
| | - Yongkai Cao
- Institute of Translational Medicine, The First Affiliated Hospital of Shenzhen University, China
| | - Huijun Li
- Department of Pharmaceuticals, People's Hospital of Zunyi City Bo Zhou District, China
| | - Xiaohan Zhang
- School of Pharmaceutical Sciences, Guizhou University, Guiyang, China
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10
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Tompkins E, Mimic B, Penn RB, Pera T. The biased M3 mAChR ligand PD 102807 mediates qualitatively distinct signaling to regulate airway smooth muscle phenotype. J Biol Chem 2023; 299:105209. [PMID: 37660916 PMCID: PMC10520882 DOI: 10.1016/j.jbc.2023.105209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 08/14/2023] [Accepted: 08/22/2023] [Indexed: 09/05/2023] Open
Abstract
Airway smooth muscle (ASM) cells attain a hypercontractile phenotype during obstructive airway diseases. We recently identified a biased M3 muscarinic acetylcholine receptor (mAChR) ligand, PD 102807, that induces GRK-/arrestin-dependent AMP-activated protein kinase (AMPK) activation to inhibit transforming growth factor-β-induced hypercontractile ASM phenotype. Conversely, the balanced mAChR agonist, methacholine (MCh), activates AMPK yet does not regulate ASM phenotype. In the current study, we demonstrate that PD 102807- and MCh-induced AMPK activation both depend on Ca2+/calmodulin-dependent kinase kinases (CaMKKs). However, MCh-induced AMPK activation is calcium-dependent and mediated by CaMKK1 and CaMKK2 isoforms. In contrast, PD 102807-induced signaling is calcium-independent and mediated by the atypical subtype protein kinase C-iota and the CaMKK1 (but not CaMKK2) isoform. Both MCh- and PD 102807-induced AMPK activation involve the AMPK α1 isoform. PD 102807-induced AMPK α1 (but not AMPK α2) isoform activation mediates inhibition of the mammalian target of rapamycin complex 1 (mTORC1) in ASM cells, as demonstrated by increased Raptor (regulatory-associated protein of mTOR) phosphorylation as well as inhibition of phospho-S6 protein and serum response element-luciferase activity. The mTORC1 inhibitor rapamycin and the AMPK activator metformin both mimic the ability of PD 102807 to attenuate transforming growth factor-β-induced α-smooth muscle actin expression (a marker of hypercontractile ASM). These data indicate that PD 102807 transduces a signaling pathway (AMPK-mediated mTORC1 inhibition) qualitatively distinct from canonical M3 mAChR signaling to prevent pathogenic remodeling of ASM, thus demonstrating PD 102807 is a biased M3 mAChR ligand with therapeutic potential for the management of obstructive airway disease.
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Affiliation(s)
- Eric Tompkins
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania, USA
| | - Bogdana Mimic
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania, USA
| | - Raymond B Penn
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania, USA
| | - Tonio Pera
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania, USA.
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Birch CA, Wedegaertner H, Orduña-Castillo LB, Gonzalez Ramirez ML, Qin H, Trejo J. Endothelial APC/PAR1 distinctly regulates cytokine-induced pro-inflammatory VCAM-1 expression. Front Mol Biosci 2023; 10:1211597. [PMID: 37692066 PMCID: PMC10483999 DOI: 10.3389/fmolb.2023.1211597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 08/04/2023] [Indexed: 09/12/2023] Open
Abstract
Introduction: Dysfunction of the endothelium impairs its' protective role and promotes inflammation and progression of vascular diseases. Activated Protein C (APC) elicits endothelial cytoprotective responses including barrier stabilization, anti-inflammatory and anti-apoptotic responses through the activation of the G protein-coupled receptor (GPCR) protease-activated receptor-1 (PAR1) and is a promising therapeutic. Despite recent advancements in developing new Activated protein C variants with clinical potential, the mechanism by which APC/PAR1 promotes different cytoprotective responses remains unclear and is important to understand to advance Activated protein C and new targets as future therapeutics. Here we examined the mechanisms by which APC/PAR1 attenuates cytokine-induced pro-inflammatory vascular cell adhesion molecule (VCAM-1) expression, a key mediator of endothelial inflammatory responses. Methods: Quantitative multiplexed mass spectrometry analysis of Activated protein C treated endothelial cells, endothelial cell transcriptomics database (EndoDB) online repository queries, biochemical measurements of protein expression, quantitative real-time polymerase chain reaction (RT-qPCR) measurement of mRNA transcript abundance, pharmacological inhibitors and siRNA transfections of human cultured endothelial cells. Results: Here we report that Activated Protein C modulates phosphorylation of tumor necrosis factor (TNF)-α signaling pathway components and attenuates of TNF-α induced VCAM-1 expression independent of mRNA stability. Unexpectedly, we found a critical role for the G protein-coupled receptor co-receptor sphingosine-1 phosphate receptor-1 (S1PR1) and the G protein receptor kinase-2 (GRK2) in mediating APC/PAR1 anti-inflammatory responses in endothelial cells. Discussion: This study provides new knowledge of the mechanisms by which different APC/PAR1 cytoprotective responses are mediated through discrete β-arrestin-2-driven signaling pathways modulated by specific G protein-coupled receptor co-receptors and GRKs.
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Affiliation(s)
- Cierra A. Birch
- Department of Pharmacology, School of Medicine, University of California, San Diego, CA, United States
| | - Helen Wedegaertner
- Department of Pharmacology, School of Medicine, University of California, San Diego, CA, United States
- Biomedical Sciences Graduate Program, University of California, San Diego, CA, United States
| | - Lennis B. Orduña-Castillo
- Department of Pharmacology, School of Medicine, University of California, San Diego, CA, United States
| | | | - Huaping Qin
- Department of Pharmacology, School of Medicine, University of California, San Diego, CA, United States
| | - JoAnn Trejo
- Department of Pharmacology, School of Medicine, University of California, San Diego, CA, United States
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12
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Fouillen A, Bous J, Granier S, Mouillac B, Sounier R. Bringing GPCR Structural Biology to Medical Applications: Insights from Both V2 Vasopressin and Mu-Opioid Receptors. MEMBRANES 2023; 13:606. [PMID: 37367810 DOI: 10.3390/membranes13060606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/05/2023] [Accepted: 06/14/2023] [Indexed: 06/28/2023]
Abstract
G-protein coupled receptors (GPCRs) are versatile signaling proteins that regulate key physiological processes in response to a wide variety of extracellular stimuli. The last decade has seen a revolution in the structural biology of clinically important GPCRs. Indeed, the improvement in molecular and biochemical methods to study GPCRs and their transducer complexes, together with advances in cryo-electron microscopy, NMR development, and progress in molecular dynamic simulations, have led to a better understanding of their regulation by ligands of different efficacy and bias. This has also renewed a great interest in GPCR drug discovery, such as finding biased ligands that can either promote or not promote specific regulations. In this review, we focus on two therapeutically relevant GPCR targets, the V2 vasopressin receptor (V2R) and the mu-opioid receptor (µOR), to shed light on the recent structural biology studies and show the impact of this integrative approach on the determination of new potential clinical effective compounds.
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Affiliation(s)
- Aurélien Fouillen
- Institut de Génomique Fonctionnelle (IGF), Université de Montpellier, CNRS, INSERM, 34000 Montpellier, France
- Centre de Biochimie Structurale (CBS), Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France
| | - Julien Bous
- Section of Receptor Biology & Signaling, Department of Physiology & Pharmacology, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Sébastien Granier
- Institut de Génomique Fonctionnelle (IGF), Université de Montpellier, CNRS, INSERM, 34000 Montpellier, France
| | - Bernard Mouillac
- Institut de Génomique Fonctionnelle (IGF), Université de Montpellier, CNRS, INSERM, 34000 Montpellier, France
| | - Remy Sounier
- Institut de Génomique Fonctionnelle (IGF), Université de Montpellier, CNRS, INSERM, 34000 Montpellier, France
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13
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Liu H, Ma H, Zeng X, Wu C, Acharya S, Sudan SK, Zhang X. Ubiquitination of GRK2 Is Required for the β-Arrestin-Biased Signaling Pathway of Dopamine D2 Receptors to Activate ERK Kinases. Int J Mol Sci 2023; 24:10031. [PMID: 37373182 DOI: 10.3390/ijms241210031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
A class-A GPCR dopamine D2 receptor (D2R) plays a critical role in the proper functioning of neuronal circuits through the downstream activation of both G-protein- and β-arrestin-dependent signaling pathways. Understanding the signaling pathways downstream of D2R is critical for developing effective therapies with which to treat dopamine (DA)-related disorders such as Parkinson's disease and schizophrenia. Extensive studies have focused on the regulation of D2R-mediated extracellular-signal-regulated kinase (ERK) 1/2 signaling; however, the manner in which ERKs are activated upon the stimulation of a specific signaling pathway of D2R remains unclear. The present study conducted a variety of experimental techniques, including loss-of-function experiments, site-directed mutagenesis, and the determination of protein interactions, in order to investigate the mechanisms underlying β-arrestin-biased signaling-pathway-mediated ERK activation. We found that the stimulation of the D2R β-arrestin signaling pathway caused Mdm2, an E3 ubiquitin ligase, to move from the nucleus to the cytoplasm and interact with tyrosine phosphorylated G-protein-coupled receptor kinase 2 (GRK2), which was facilitated by Src, a non-receptor tyrosine kinase. This interaction led to the ubiquitination of GRK2, which then moved to the plasma membrane and interacted with activated D2R, followed by the phosphorylation of D2R as well as the mediation of ERK activation. In conclusion, Mdm2-mediated GRK2 ubiquitination, which is selectively triggered by the stimulation of the D2R β-arrestin signaling pathway, is necessary for GRK2 membrane translocation and its interaction with D2R, which in turn mediates downstream ERK signaling. This study is primarily novel and provides essential information with which to better understand the detailed mechanisms of D2R-dependent signaling.
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Affiliation(s)
- Haiping Liu
- School of Pharmaceutical Sciences, Guizhou University, Guiyang 550025, China
| | - Haixiang Ma
- School of Pharmaceutical Sciences, Guizhou University, Guiyang 550025, China
| | - Xingyue Zeng
- School of Pharmaceutical Sciences, Guizhou University, Guiyang 550025, China
| | - Chengyan Wu
- School of Pharmaceutical Sciences, Guizhou University, Guiyang 550025, China
| | - Srijan Acharya
- Mitchell Cancer Institute, School of Medicine, University of South Alabama, Mobile, AL 36604, USA
| | - Sarabjeet Kour Sudan
- Mitchell Cancer Institute, School of Medicine, University of South Alabama, Mobile, AL 36604, USA
| | - Xiaohan Zhang
- School of Pharmaceutical Sciences, Guizhou University, Guiyang 550025, China
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14
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Bous J, Fouillen A, Orcel H, Granier S, Bron P, Mouillac B. Structures of the arginine-vasopressin and oxytocin receptor signaling complexes. VITAMINS AND HORMONES 2023; 123:67-107. [PMID: 37718002 DOI: 10.1016/bs.vh.2022.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Arginine-vasopressin (AVP) and oxytocin (OT) are neurohypophysial hormones which share a high sequence and structure homology. These are two cyclic C-terminally amidated nonapeptides with different residues at position 3 and 8. In mammals, AVP and OT exert their multiple biological functions through a specific G protein-coupled receptor family: four receptors are identified, the V1a, V1b, V2 receptors (V1aR, V1bR and V2R) and the OT receptor (OTR). The chemical structure of AVP and OT was elucidated in the early 1950s. Thanks to X-ray crystallography and cryo-electron microscopy, it took however 70 additional years to determine the three-dimensional structures of the OTR and the V2R in complex with their natural agonist ligands and with different signaling partners, G proteins and β-arrestins. Today, the comparison of the different AVP/OT receptor structures gives structural insights into their orthosteric ligand binding pocket, their molecular mechanisms of activation, and their interfaces with canonical Gs, Gq and β-arrestin proteins. It also paves the way to future rational drug design and therapeutic compound development. Indeed, agonist, antagonist, biased agonist, or pharmacological chaperone analogues of AVP and OT are promising candidates to regulate different physiological functions and treat several pathologies.
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Affiliation(s)
- Julien Bous
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France; CBS (Centre de Biologie Structurale), Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Aurélien Fouillen
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France; CBS (Centre de Biologie Structurale), Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Hélène Orcel
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Sébastien Granier
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Patrick Bron
- CBS (Centre de Biologie Structurale), Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Bernard Mouillac
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France.
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15
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Tompkins E, Mimic B, Cuevas-Mora K, Schorsch H, Shah SD, Deshpande DA, Benovic JL, Penn RB, Pera T. PD 102807 Induces M3 mAChR-Dependent GRK-/Arrestin-Biased Signaling in Airway Smooth Muscle Cells. Am J Respir Cell Mol Biol 2022; 67:550-561. [PMID: 35944139 PMCID: PMC9651198 DOI: 10.1165/rcmb.2021-0320oc] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 08/09/2022] [Indexed: 11/24/2022] Open
Abstract
G protein-coupled receptors (GPCRs) not only are turned on or off to control canonical G protein signaling but also may be fine-tuned to promote qualitative/biased signaling. Qualitative signaling by M3 muscarinic acetylcholine receptors (mAChRs) has been proposed, but its impact on physiologic systems remains unclear, and currently no biased M3 mAChR ligands have been described. Herein, we identify PD 102807 as a biased M3 ligand and delineate its signaling and function in human airway smooth muscle (ASM) cells. PD 102807 induced M3-mediated β-arrestin recruitment but not calcium mobilization. PD 102807 inhibited methacholine (MCh)-induced calcium mobilization in (M3-expressing) ASM cells. PD 102807 induced phosphorylation of AMP-activated protein kinase (AMPK) and the downstream effector acetyl-coenzyme A carboxylase (ACC). PD 102807- induced phosphorylated (p)-AMPK levels were greatly reduced in ASM cells with minimal M3 expression and were not inhibited by the Gq inhibitor YM-254890. Induction of p-AMPK and p-ACC was inhibited by β-arrestin 1 or GRK2/3 knockdown. Similarly, MCh induced phosphorylation of AMPK/ACC, but these effects were Gq dependent and unaffected by GRK2/3 knockdown. Consistent with the known ability of AMPK to inhibit transforming growth factor β (TGF-β)-mediated functions, PD 102807 inhibited TGF-β-induced SMAD-Luc activity, sm-α-actin expression, actin stress fiber formation, and ASM cell hypercontractility. These findings reveal that PD 102807 is a biased M3 ligand that inhibits M3-transduced Gq signaling but promotes Gq protein-independent, GRK-/arrestin-dependent, M3-mediated AMPK signaling, which in turn regulates ASM phenotype and contractile function. Consequently, biased M3 ligands hold significant promise as therapeutic agents capable of exploiting the pleiotropic nature of M3 signaling.
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Affiliation(s)
- Eric Tompkins
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania; and
| | - Bogdana Mimic
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania; and
| | - Karina Cuevas-Mora
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania; and
| | - Hannah Schorsch
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania; and
| | - Sushrut D. Shah
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania; and
| | - Deepak A. Deshpande
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania; and
| | - Jeffrey L. Benovic
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Raymond B. Penn
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania; and
| | - Tonio Pera
- Department of Medicine, Center for Translational Medicine, Jane and Leonard Korman Respiratory Institute, Philadelphia, Pennsylvania; and
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16
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Chimeric GPCRs mimic distinct signaling pathways and modulate microglia responses. Nat Commun 2022; 13:4728. [PMID: 35970889 PMCID: PMC9378622 DOI: 10.1038/s41467-022-32390-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 07/28/2022] [Indexed: 11/30/2022] Open
Abstract
G protein-coupled receptors (GPCRs) regulate processes ranging from immune responses to neuronal signaling. However, ligands for many GPCRs remain unknown, suffer from off-target effects or have poor bioavailability. Additionally, dissecting cell type-specific responses is challenging when the same GPCR is expressed on different cells within a tissue. Here, we overcome these limitations by engineering DREADD-based GPCR chimeras that bind clozapine-N-oxide and mimic a GPCR-of-interest. We show that chimeric DREADD-β2AR triggers responses comparable to β2AR on second messenger and kinase activity, post-translational modifications, and protein-protein interactions. Moreover, we successfully recapitulate β2AR-mediated filopodia formation in microglia, an immune cell capable of driving central nervous system inflammation. When dissecting microglial inflammation, we included two additional DREADD-based chimeras mimicking microglia-enriched GPR65 and GPR109A. DREADD-β2AR and DREADD-GPR65 modulate the inflammatory response with high similarity to endogenous β2AR, while DREADD-GPR109A shows no impact. Our DREADD-based approach allows investigation of cell type-dependent pathways without known endogenous ligands. Understanding the function of GPCRs requires stimulation with their specific ligands. Here, the authors design chemogenetic G-protein coupled receptors that allows for the study of receptors without knowing the immediate ligand, and demonstrate its use for the β2-adrenergic receptor in microglia.
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17
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Structural basis and molecular mechanism of biased GPBAR signaling in regulating NSCLC cell growth via YAP activity. Proc Natl Acad Sci U S A 2022; 119:e2117054119. [PMID: 35858343 PMCID: PMC9303995 DOI: 10.1073/pnas.2117054119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The G protein-coupled bile acid receptor (GPBAR) is the membrane receptor for bile acids and a driving force of the liver-bile acid-microbiota-organ axis to regulate metabolism and other pathophysiological processes. Although GPBAR is an important therapeutic target for a spectrum of metabolic and neurodegenerative diseases, its activation has also been found to be linked to carcinogenesis, leading to potential side effects. Here, via functional screening, we found that two specific GPBAR agonists, R399 and INT-777, demonstrated strikingly different regulatory effects on the growth and apoptosis of non-small cell lung cancer (NSCLC) cells both in vitro and in vivo. Further mechanistic investigation showed that R399-induced GPBAR activation displayed an obvious bias for β-arrestin 1 signaling, thus promoting YAP signaling activation to stimulate cell proliferation. Conversely, INT-777 preferentially activated GPBAR-Gs signaling, thus inactivating YAP to inhibit cell proliferation and induce apoptosis. Phosphorylation of GPBAR by GRK2 at S310/S321/S323/S324 sites contributed to R399-induced GPBAR-β-arrestin 1 association. The cryoelectron microscopy (cryo-EM) structure of the R399-bound GPBAR-Gs complex enabled us to identify key interaction residues and pivotal conformational changes in GPBAR responsible for the arrestin signaling bias and cancer cell proliferation. In summary, we demonstrate that different agonists can regulate distinct functions of cell growth and apoptosis through biased GPBAR signaling and control of YAP activity in a NSCLC cell model. The delineated mechanism and structural basis may facilitate the rational design of GPBAR-targeting drugs with both metabolic and anticancer benefits.
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18
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Todd NK, Huang Y, Lee JY, Doruker P, Krieger JM, Salisbury R, MacDonald M, Bahar I, Thathiah A. GPCR kinases generate an APH1A phosphorylation barcode to regulate amyloid-β generation. Cell Rep 2022; 40:111110. [PMID: 35858570 PMCID: PMC9373432 DOI: 10.1016/j.celrep.2022.111110] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 05/05/2022] [Accepted: 06/28/2022] [Indexed: 11/03/2022] Open
Abstract
Emerging evidence suggests that G protein-coupled receptor (GPCR) kinases (GRKs) are associated with the pathophysiology of Alzheimer's disease (AD). However, GRKs have not been directly implicated in regulation of the amyloid-β (Aβ) pathogenic cascade in AD. Here, we determine that GRKs phosphorylate a non-canonical substrate, anterior pharynx-defective 1A (APH1A), an integral component of the γ-secretase complex. Significantly, we show that GRKs generate distinct phosphorylation barcodes in intracellular loop 2 (ICL2) and the C terminus of APH1A, which differentially regulate recruitment of the scaffolding protein β-arrestin 2 (βarr2) to APH1A and γ-secretase-mediated Aβ generation. Further molecular dynamics simulation studies reveal an interaction between the βarr2 finger loop domain and ICL2 and ICL3 of APH1A, similar to a GPCR-β-arrestin complex, which regulates γ-secretase activity. Collectively, these studies provide insight into the molecular and structural determinants of the APH1A-βarr2 interaction that critically regulate Aβ generation.
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Affiliation(s)
- Nicholas K Todd
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; Graduate Program in Molecular Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Yunhong Huang
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Ji Young Lee
- Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Pemra Doruker
- Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - James M Krieger
- Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Ryan Salisbury
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Matthew MacDonald
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Ivet Bahar
- Department of Computational and Systems Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Amantha Thathiah
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; University of Pittsburgh Brain Institute, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
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19
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Recent advances in function and structure of two leukotriene B 4 receptors: BLT1 and BLT2. Biochem Pharmacol 2022; 203:115178. [PMID: 35850310 DOI: 10.1016/j.bcp.2022.115178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/12/2022] [Accepted: 07/12/2022] [Indexed: 11/21/2022]
Abstract
Leukotriene B4 (LTB4) is generated by the enzymatic oxidation of arachidonic acid, which is then released from the cell membrane and acts as a potent activator of leukocytes and other inflammatory cells. Numerous studies have demonstrated the physiological and pathophysiological significance of this lipid in various diseases. LTB4 exerts its activities by binding to its specific G protein-coupled receptors (GPCRs): BLT1 and BLT2. In mouse disease models, treatment with BLT1 antagonists or BLT1 gene ablation attenuated various diseases, including bronchial asthma, arthritis, and psoriasis, whereas BLT2 deficiency exacerbated several diseases in the skin, cornea, and small intestine. Therefore, BLT1 inhibitors and BLT2 activators could be beneficial for the treatment of several inflammatory and immune disorders. As a result, attractive compounds targeting LTB4 receptors have been developed by several pharmaceutical companies. This review aims to understand the potential of BLT1 and BLT2 as therapeutic targets for the treatment of various inflammatory diseases. In addition, recent topics are discussed with major focuses on the structure and post-translational modifications of BLT1 and BLT2. Collectively, current evidence on modulating LTB4 receptor functions provides new strategies for the treatment of various diseases.
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20
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Structural Insights into the Intrinsically Disordered GPCR C-Terminal Region, Major Actor in Arrestin-GPCR Interaction. Biomolecules 2022; 12:biom12050617. [PMID: 35625550 PMCID: PMC9138321 DOI: 10.3390/biom12050617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/12/2022] [Accepted: 04/19/2022] [Indexed: 02/04/2023] Open
Abstract
Arrestin-dependent pathways are a central component of G protein-coupled receptor (GPCRs) signaling. However, the molecular processes regulating arrestin binding are to be further illuminated, in particular with regard to the structural impact of GPCR C-terminal disordered regions. Here, we used an integrated biophysical strategy to describe the basal conformations of the C-terminal domains of three class A GPCRs, the vasopressin V2 receptor (V2R), the growth hormone secretagogue or ghrelin receptor type 1a (GHSR) and the β2-adernergic receptor (β2AR). By doing so, we revealed the presence of transient secondary structures in these regions that are potentially involved in the interaction with arrestin. These secondary structure elements differ from those described in the literature in interaction with arrestin. This suggests a mechanism where the secondary structure conformational preferences in the C-terminal regions of GPCRs could be a central feature for optimizing arrestins recognition.
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21
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Reiter E. [β-arrestins, their mechanisms of action and multiple roles in the biology of G protein-coupled receptors]. Biol Aujourdhui 2022; 215:107-118. [PMID: 35275055 DOI: 10.1051/jbio/2021010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Indexed: 06/14/2023]
Abstract
The stimulation of G protein-coupled receptors (GPCRs) induces biological responses to a wide range of extracellular cues. The heterotrimeric G proteins, which are recruited to the active conformation of GPCRs, lead to the generation of various diffusible second messengers. Only two other families of proteins exhibit the remarkable characteristic of recognizing and binding to the active conformation of most GPCRs: GPCR kinases (GRKs) and β-arrestins. These two families of proteins were initially identified as key players in the desensitization of G protein activation by GPCRs. Over the years, β-arrestins have been implicated in an increasing number of interactions with non-receptor proteins, expanding the range of cellular functions in which they are involved. It is now well established that β-arrestins, by scaffolding and recruiting protein complexes in an agonist-dependent manner, directly regulate the trafficking and signaling of GPCRs. Remarkable advances have been made in recent years which have made it possible i) to identify biased ligands capable, by stabilizing particular conformations of a growing number of GPCRs, of activating or blocking the action of β-arrestins independently of that of G proteins, some of these ligands holding great therapeutic interest; ii) to demonstrate β-arrestins' role in the compartmentalization of GPCR signaling within the cell, and iii) to understand the molecular details of their interaction with GPCRs and of their activation through structural and biophysical approaches.
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Affiliation(s)
- Eric Reiter
- CNRS, IFCE, INRAE, Université de Tours, PRC, 37380 Nouzilly, France - Inria, Centre de recherche Inria Saclay-Île-de-France, 91120 Palaiseau, France
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22
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Agonist-induced phosphorylation of orthologues of the orphan receptor GPR35 functions as an activation sensor. J Biol Chem 2022; 298:101655. [PMID: 35101446 PMCID: PMC8892012 DOI: 10.1016/j.jbc.2022.101655] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 12/29/2022] Open
Abstract
G protein-coupled receptor 35 (GPR35) is poorly characterized but nevertheless has been revealed to have diverse roles in areas including lower gut inflammation and pain. The development of novel reagents and tools will greatly enhance analysis of GPR35 functions in health and disease. Here, we used mass spectrometry, mutagenesis, and [32P] orthophosphate labeling to identify that all five hydroxy-amino acids in the C-terminal tail of human GPR35a became phosphorylated in response to agonist occupancy of the receptor and that, apart from Ser294, each of these contributed to interactions with arretin-3, which inhibits further G protein-coupled receptor signaling. We found that Ser303 was key to such interactions; the serine corresponding to human GPR35a residue 303 also played a dominant role in arrestin-3 interactions for both mouse and rat GPR35. We also demonstrated that fully phospho-site–deficient mutants of human GPR35a and mouse GPR35 failed to interact effectively with arrestin-3, and the human phospho-deficient variant was not internalized from the surface of cells in response to agonist treatment. Even in cells stably expressing species orthologues of GPR35, a substantial proportion of the expressed protein(s) was determined to be immature. Finally, phospho-site–specific antisera targeting the region encompassing Ser303 in human (Ser301 in mouse) GPR35a identified only the mature forms of GPR35 and provided effective sensors of the activation status of the receptors both in immunoblotting and immunocytochemical studies. Such antisera may be useful tools to evaluate target engagement in drug discovery and target validation programs.
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23
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Drube J, Haider RS, Matthees ESF, Reichel M, Zeiner J, Fritzwanker S, Ziegler C, Barz S, Klement L, Filor J, Weitzel V, Kliewer A, Miess-Tanneberg E, Kostenis E, Schulz S, Hoffmann C. GPCR kinase knockout cells reveal the impact of individual GRKs on arrestin binding and GPCR regulation. Nat Commun 2022; 13:540. [PMID: 35087057 PMCID: PMC8795447 DOI: 10.1038/s41467-022-28152-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 01/06/2022] [Indexed: 12/19/2022] Open
Abstract
G protein-coupled receptors (GPCRs) activate G proteins and undergo a complex regulation by interaction with GPCR kinases (GRKs) and the formation of receptor-arrestin complexes. However, the impact of individual GRKs on arrestin binding is not clear. We report the creation of eleven combinatorial HEK293 knockout cell clones lacking GRK2/3/5/6, including single, double, triple and the quadruple GRK knockout. Analysis of β-arrestin1/2 interactions for twelve GPCRs in our GRK knockout cells enables the differentiation of two main receptor subsets: GRK2/3-regulated and GRK2/3/5/6-regulated receptors. Furthermore, we identify GPCRs that interact with β-arrestins via the overexpression of specific GRKs even in the absence of agonists. Finally, using GRK knockout cells, PKC inhibitors and β-arrestin mutants, we present evidence for differential receptor-β-arrestin1/2 complex configurations mediated by selective engagement of kinases. We anticipate our GRK knockout platform to facilitate the elucidation of previously unappreciated details of GRK-specific GPCR regulation and β-arrestin complex formation.
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Affiliation(s)
- J Drube
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - R S Haider
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - E S F Matthees
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - M Reichel
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - J Zeiner
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115, Bonn, Germany
| | - S Fritzwanker
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Drackendorfer Straße 1, D-07747, Jena, Germany
| | - C Ziegler
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - S Barz
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - L Klement
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - J Filor
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - V Weitzel
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany
| | - A Kliewer
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Drackendorfer Straße 1, D-07747, Jena, Germany
| | - E Miess-Tanneberg
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Drackendorfer Straße 1, D-07747, Jena, Germany
| | - E Kostenis
- Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115, Bonn, Germany
| | - S Schulz
- Institut für Pharmakologie und Toxikologie, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Drackendorfer Straße 1, D-07747, Jena, Germany
| | - C Hoffmann
- Institut für Molekulare Zellbiologie, CMB - Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Hans-Knöll-Straße 2, D-07745, Jena, Germany.
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Reichel M, Weitzel V, Klement L, Hoffmann C, Drube J. Suitability of GRK Antibodies for Individual Detection and Quantification of GRK Isoforms in Western Blots. Int J Mol Sci 2022; 23:ijms23031195. [PMID: 35163118 PMCID: PMC8835249 DOI: 10.3390/ijms23031195] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 02/04/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are regulated by GPCR kinases (GRKs) which phosphorylate intracellular domains of the active receptor. This results in the recruitment of arrestins, leading to desensitization and internalization of the GPCR. Aside from acting on GPCRs, GRKs regulate a variety of membrane, cytosolic, and nuclear proteins not only via phosphorylation but also by acting as scaffolding partners. GRKs’ versatility is also reflected by their diverse roles in pathological conditions such as cancer, malaria, Parkinson’s-, cardiovascular-, and metabolic disease. Reliable tools to study GRKs are the key to specify their role in complex cellular signaling networks. Thus, we examined the specificity of eight commercially available antibodies targeting the four ubiquitously expressed GRKs (GRK2, GRK3, GRK5, and GRK6) in Western blot analysis. We identified one antibody that did not recognize its antigen, as well as antibodies that showed unspecific signals or cross-reactivity. Hence, we strongly recommend testing any antibody with exogenously expressed proteins to clearly confirm identity of the obtained Western blot results. Utilizing the most-suitable antibodies, we established the Western blot-based, cost-effective simple tag-guided analysis of relative protein abundance (STARPA). This method allows comparison of protein levels obtained by immunoblotting with different antibodies. Furthermore, we applied STARPA to determine GRK protein levels in nine commonly used cell lines, revealing differential isoform expression.
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Kim K, Han Y, Duan L, Chung KY. Scaffolding of Mitogen-Activated Protein Kinase Signaling by β-Arrestins. Int J Mol Sci 2022; 23:ijms23021000. [PMID: 35055186 PMCID: PMC8778048 DOI: 10.3390/ijms23021000] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/14/2022] [Accepted: 01/15/2022] [Indexed: 12/19/2022] Open
Abstract
β-arrestins were initially identified to desensitize and internalize G-protein-coupled receptors (GPCRs). Receptor-bound β-arrestins also initiate a second wave of signaling by scaffolding mitogen-activated protein kinase (MAPK) signaling components, MAPK kinase kinase, MAPK kinase, and MAPK. In particular, β-arrestins facilitate ERK1/2 or JNK3 activation by scaffolding signal cascade components such as ERK1/2-MEK1-cRaf or JNK3-MKK4/7-ASK1. Understanding the precise molecular and structural mechanisms of β-arrestin-mediated MAPK scaffolding assembly would deepen our understanding of GPCR-mediated MAPK activation and provide clues for the selective regulation of the MAPK signaling cascade for therapeutic purposes. Over the last decade, numerous research groups have attempted to understand the molecular and structural mechanisms of β-arrestin-mediated MAPK scaffolding assembly. Although not providing the complete mechanism, these efforts suggest potential binding interfaces between β-arrestins and MAPK signaling components and the mechanism for MAPK signal amplification by β-arrestin-mediated scaffolding. This review summarizes recent developments of cellular and molecular works on the scaffolding mechanism of β-arrestin for MAPK signaling cascade.
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Hoare SRJ, Tewson PH, Sachdev S, Connor M, Hughes TE, Quinn AM. Quantifying the Kinetics of Signaling and Arrestin Recruitment by Nervous System G-Protein Coupled Receptors. Front Cell Neurosci 2022; 15:814547. [PMID: 35110998 PMCID: PMC8801586 DOI: 10.3389/fncel.2021.814547] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 12/17/2021] [Indexed: 11/13/2022] Open
Abstract
Neurons integrate inputs over different time and space scales. Fast excitatory synapses at boutons (ms and μm), and slow modulation over entire dendritic arbors (seconds and mm) are all ultimately combined to produce behavior. Understanding the timing of signaling events mediated by G-protein-coupled receptors is necessary to elucidate the mechanism of action of therapeutics targeting the nervous system. Measuring signaling kinetics in live cells has been transformed by the adoption of fluorescent biosensors and dyes that convert biological signals into optical signals that are conveniently recorded by microscopic imaging or by fluorescence plate readers. Quantifying the timing of signaling has now become routine with the application of equations in familiar curve fitting software to estimate the rates of signaling from the waveform. Here we describe examples of the application of these methods, including (1) Kinetic analysis of opioid signaling dynamics and partial agonism measured using cAMP and arrestin biosensors; (2) Quantifying the signaling activity of illicit synthetic cannabinoid receptor agonists measured using a fluorescent membrane potential dye; (3) Demonstration of multiplicity of arrestin functions from analysis of biosensor waveforms and quantification of the rates of these processes. These examples show how temporal analysis provides additional dimensions to enhance the understanding of GPCR signaling and therapeutic mechanisms in the nervous system.
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Affiliation(s)
- Sam R. J. Hoare
- Pharmechanics LLC, Owego, NY, United States
- *Correspondence: Sam R. J. Hoare
| | | | - Shivani Sachdev
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
| | - Mark Connor
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
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Patel M, Matti C, Grimsey NL, Legler DF, Javitch JA, Finlay DB, Glass M. Delineating the interactions between the cannabinoid CB 2 receptor and its regulatory effectors; β-arrestins and G protein-coupled receptor kinases. Br J Pharmacol 2021; 179:2223-2239. [PMID: 34811740 DOI: 10.1111/bph.15748] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/20/2021] [Accepted: 11/10/2021] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE The cannabinoid CB2 receptor (CB2 ) is a promising therapeutic target for modulating inflammation. However, little is known surrounding the mechanisms underpinning CB2 desensitisation and regulation, particularly the role of G protein-coupled receptor kinases (GRKs). Here, we evaluated the role of six GRK isoforms in β-arrestin recruitment to CB2 . Mutagenesis of several distal C-terminal aspartic acid residues was also performed in an attempt to delineate additional structural elements involved in the regulation of CB2 . EXPERIMENTAL APPROACH In CB2 -expressing HEK 293 cells, β-arrestin translocation was measured using real-time BRET assays. G protein dissociation BRET assays were performed to assess the activation and desensitisation of CB2 in the presence of β-arrestin 2. KEY RESULTS Overexpression of GRK isoforms 1-6 failed to considerably improve translocation of either β-arrestin 1 or β-arrestin 2 to CB2 . Consistent with this, inhibition of endogenous GRK2/3 did not substantially reduce β-arrestin 2 translocation. Mutagenesis of C-terminal aspartic acid residues resulted in attenuation of β-arrestin 2 translocation, which translated to a reduction in desensitisation of G protein activation. CONCLUSION AND IMPLICATIONS Our findings suggest that CB2 does not adhere to the classical GPCR regulatory paradigm, entailing GRK- and β-arrestin-mediated desensitisation. Instead, C-terminal aspartic acid residues may act as phospho-mimics to induce β-arrestin activation. This study provides novel insights into the regulatory mechanisms of CB2 , which may aid in our understanding of drug tolerance and dependence.
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Affiliation(s)
- Monica Patel
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Christoph Matti
- Biotechnology Institute Thurgau (BITg) at the University of Konstanz, Kreuzlingen, Switzerland
| | - Natasha L Grimsey
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Daniel F Legler
- Biotechnology Institute Thurgau (BITg) at the University of Konstanz, Kreuzlingen, Switzerland.,Faculty of Biology, University of Konstanz, Konstanz, Germany.,Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Jonathan A Javitch
- Department of Psychiatry and Pharmacology, Columbia University Vagelos College of Physicians and Surgeons, New York, New York, United States.,Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, New York, United States
| | - David B Finlay
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Michelle Glass
- Department of Pharmacology and Toxicology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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Identification of Molecular Markers of Clozapine Action in Ketamine-Induced Cognitive Impairment: A GPCR Signaling PathwayFinder Study. Int J Mol Sci 2021; 22:ijms222212203. [PMID: 34830086 PMCID: PMC8621432 DOI: 10.3390/ijms222212203] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 11/25/2022] Open
Abstract
Background: Cognitive disorders associated with schizophrenia are closely linked to prefrontal cortex (PFC) dysfunction. Administration of the non-competitive NMDA receptor antagonist ketamine (KET) induces cognitive impairment in animals, producing effects similar to those observed in schizophrenic patients. In a previous study, we showed that KET (20 mg/kg) induces cognitive deficits in mice and that administration of clozapine (CLZ) reverses this effect. To identify biochemical mechanisms related to CLZ actions in the context of KET-induced impairment, we performed a biochemical analysis using the same experimental paradigm—acute and sub-chronic administration of these drugs (0.3 and 1 mg/kg). Methods: Since the effect of CLZ mainly depends on G-protein-related receptors, we used the Signaling PathwayFinder Kit to identify 84 genes involved in GPCR-related signal transduction and then verified the genes that were statistically significantly different on a larger group of mice using RT-PCR and Western blot analyses after the administration of acute and sub-chronic drugs. Results: Of the 84 genes involved in GPCR-related signal transduction, the expression of six, βarrestin1, βarrestin2, galanin receptor 2 (GalR2), dopamine receptor 2 (DRD2), metabotropic glutamate receptor 1 (mGluR1), and metabotropic glutamate receptor 5 (mGluR5), was significantly altered. Since these genes affect the levels of other signaling proteins, e.g., extracellular signal-regulated kinase 1/2 (ERK1/2), G protein-coupled receptor kinase 2 (Grk2), and G protein-gated inwardly rectifying potassium 3 (Girk3), we determined their levels in PFC using Western blot. Most of the observed changes occurred after acute treatment with 0.3 mg/kg CLZ. We showed that acute treatment with CLZ at a lower dose significantly increased βarrestin1 and ERK1/2. KET treatment induced the upregulation of βarrestin1. Joint administration of these drugs had no effect on the βarrestin1 level. Conclusion: The screening kit we used to study the expression of GPCR-related signal transduction allowed us to select several important genes affected by CLZ. However, the obtained data do not explain the mechanism of action of CLZ that is responsible for reversing KET-induced cognitive impairment.
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Alonazi ASA, Willets JM. G protein-coupled receptor kinase 2 is essential to enable vasoconstrictor-mediated arterial smooth muscle proliferation. Cell Signal 2021; 88:110152. [PMID: 34555505 DOI: 10.1016/j.cellsig.2021.110152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/07/2021] [Accepted: 09/15/2021] [Indexed: 01/05/2023]
Abstract
Hypertension is associated with increased production and circulation of vasoconstrictors, resulting in enhanced signalling through their cognate G protein-coupled receptors (GPCR). Prolonged vasoconstrictor GPCR signalling increases arterial contraction and stimulates signalling pathways that promote vascular smooth muscle cell (VSMC) proliferation, contributing to the development of atherosclerotic plaques, re-stenosis lesions and vascular remodelling. GPCR signalling through phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) promotes VSMC proliferation. In VSMC, G protein-coupled receptor kinase 2 (GRK2) is known to regulate numerous vasoconstrictor GPCRs and their downstream signalling pathways. As GRK2 is implicated in controlling various aspects of cellular growth, we examined whether GRK2 could affect VSMC proliferation. Using two indices of cell growth, we show that PI3K inhibition and depletion of GRK2 expression produced a similar ablation of pro-proliferative vasoconstrictor-stimulated VSMC growth. Furthermore, GRK2-knockdown ablated the sustained phase of endothelin-1 and angiotensin-II-stimulated Akt phosphorylation, whilst the peak (5 min) phase was unaffected. Conversely, the GRK2 inhibitor compound 101 did not affect vasoconstrictor-driven Akt phosphorylation. Vasoconstrictor-stimulated phosphorylation of the Akt substrates GSK3α and GSK3β was ablated following RNAi-mediated GRK2 depletion, or after PI3K inhibition. Moreover, GRK2 knockdown prevented endothelin-1 and angiotensin-II from increasing cyclin D1 expression. These data suggest GRK2 expression is essential to facilitate vasoconstrictor-driven VSMC proliferation through its ability to promote efficient prolonged PI3K-Akt signalling, and thus relieve the GSK3-mediated block on cell cycling. Considering VSMC GRK2 expression increases early in the development of hypertension, this highlights the potential for GRK2 to promote VSMC growth and exacerbate hypertensive pathophysiological vascular remodelling.
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Affiliation(s)
- Asma S A Alonazi
- Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Lancaster Road, Leicester LE1 7RH, United Kingdom; Department of Pharmacology and Toxicology, Pharmacy College, King Saud University, Riyadh, Saudi Arabia
| | - Jonathon M Willets
- Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Lancaster Road, Leicester LE1 7RH, United Kingdom.
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Alhosaini K, Azhar A, Alonazi A, Al-Zoghaibi F. GPCRs: The most promiscuous druggable receptor of the mankind. Saudi Pharm J 2021; 29:539-551. [PMID: 34194261 PMCID: PMC8233523 DOI: 10.1016/j.jsps.2021.04.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 04/13/2021] [Indexed: 12/11/2022] Open
Abstract
All physiological events in living organisms originated as specific chemical/biochemical signals on the cell surface and transmitted into the cytoplasm. This signal is translated within milliseconds-hours to a specific and unique order required to maintain optimum performance and homeostasis of living organisms. Examples of daily biological functions include neuronal communication and neurotransmission in the process of learning and memory, secretion (hormones, sweat, and saliva), muscle contraction, cellular growth, differentiation and migration during wound healing, and immunity to fight infections. Among the different transducers for such life-dependent signals is the large family of G protein-coupled receptors (GPCRs). GPCRs constitute roughly 800 genes, corresponding to 2% of the human genome. While GPCRs control a plethora of pathophysiological disorders, only approximately one-third of GPCR families have been deorphanized and characterized. Recent drug data show that around 40% of the recommended drugs available in the market target mainly GPCRs. In this review, we presented how such system signals, either through G protein or via other players, independent of G protein, function within the biological system. We also discussed drugs in the market or clinical trials targeting mainly GPCRs in various diseases, including cancer.
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Key Words
- AC, Adenylyl Cyclase
- Arrestin
- CCR, Chemokine Receptor
- COX, Cyclooxygenase
- DAG, Diacylglycerol
- Drugs
- ERK, Extracellular signal-Regulated Kinase
- G proteins
- GIP, Gastric Inhibitory Peptide
- GLP1R, Glucagon-Like Peptide-1 Receptor
- GPCR
- GRKs
- GRKs, G protein-coupled Receptor Kinases
- Heterodimerization
- IP3, Inositol 1,4,5-triphosphate
- MAPK, Mitogen-Activated Protein Kinase
- NMDA, N-Methyl D-Aspartate
- Nbs, Nanobodies
- PAR-1, Protease Activated Receptor 1
- PIP2, Phosphatidylinositol-4,5-bisphosphate
- PKA, Protein Kinase A
- Signaling
- cAMP, cyclic AMP
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Affiliation(s)
- Khaled Alhosaini
- Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Post Box 2457, Riyadh 11451, Saudi Arabia
| | - Asim Azhar
- Interdisciplinary Biotechnology Unit, AMU Aligarh, UP, India
| | - Asma Alonazi
- Department of Pharmacology & Toxicology, College of Pharmacy, King Saud University, Post Box 2457, Riyadh 11451, Saudi Arabia
| | - F Al-Zoghaibi
- Molecular BioMedicine Program, Research Centre, King Faisal Specialist Hospital and Research Centre, P.O.Box: 3354, MBC:03, Riyadh 11211, Saudi Arabia
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Wanka L, Behr V, Beck-Sickinger AG. Arrestin-dependent internalization of rhodopsin-like G protein-coupled receptors. Biol Chem 2021; 403:133-149. [PMID: 34036761 DOI: 10.1515/hsz-2021-0128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/28/2021] [Indexed: 01/14/2023]
Abstract
The internalization of G protein-coupled receptors (GPCRs) is an important mechanism regulating the signal strength and limiting the opportunity of receptor activation. Based on the importance of GPCRs, the detailed knowledge about the regulation of signal transduction is crucial. Here, current knowledge about the agonist-induced, arrestin-dependent internalization process of rhodopsin-like GPCRs is reviewed. Arrestins are conserved molecules that act as key players within the internalization process of many GPCRs. Based on highly conserved structural characteristics within the rhodopsin-like GPCRs, the identification of arrestin interaction sites in model systems can be compared and used for the investigation of internalization processes of other receptors. The increasing understanding of this essential regulation mechanism of receptors can be used for drug development targeting rhodopsin-like GPCRs. Here, we focus on the neuropeptide Y receptor family, as these receptors transmit various physiological processes such as food intake, energy homeostasis, and regulation of emotional behavior, and are further involved in pathophysiological processes like cancer, obesity and mood disorders. Hence, this receptor family represents an interesting target for the development of novel therapeutics requiring the understanding of the regulatory mechanisms influencing receptor mediated signaling.
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Affiliation(s)
- Lizzy Wanka
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Brüderstr. 34, D-04103Leipzig, Germany
| | - Victoria Behr
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Brüderstr. 34, D-04103Leipzig, Germany
| | - Annette G Beck-Sickinger
- Institute of Biochemistry, Faculty of Life Sciences, Leipzig University, Brüderstr. 34, D-04103Leipzig, Germany
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Matthees ESF, Haider RS, Hoffmann C, Drube J. Differential Regulation of GPCRs-Are GRK Expression Levels the Key? Front Cell Dev Biol 2021; 9:687489. [PMID: 34109182 PMCID: PMC8182058 DOI: 10.3389/fcell.2021.687489] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 04/29/2021] [Indexed: 01/14/2023] Open
Abstract
G protein-coupled receptors (GPCRs) comprise the largest family of transmembrane receptors and their signal transduction is tightly regulated by GPCR kinases (GRKs) and β-arrestins. In this review, we discuss novel aspects of the regulatory GRK/β-arrestin system. Therefore, we briefly revise the origin of the "barcode" hypothesis for GPCR/β-arrestin interactions, which states that β-arrestins recognize different receptor phosphorylation states to induce specific functions. We emphasize two important parameters which may influence resulting GPCR phosphorylation patterns: (A) direct GPCR-GRK interactions and (B) tissue-specific expression and availability of GRKs and β-arrestins. In most studies that focus on the molecular mechanisms of GPCR regulation, these expression profiles are underappreciated. Hence we analyzed expression data for GRKs and β-arrestins in 61 tissues annotated in the Human Protein Atlas. We present our analysis in the context of pathophysiological dysregulation of the GPCR/GRK/β-arrestin system. This tissue-specific point of view might be the key to unraveling the individual impact of different GRK isoforms on GPCR regulation.
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Affiliation(s)
| | | | - Carsten Hoffmann
- Institut für Molekulare Zellbiologie, CMB – Center for Molecular Biomedicine, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, Jena, Germany
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Bous J, Orcel H, Floquet N, Leyrat C, Lai-Kee-Him J, Gaibelet G, Ancelin A, Saint-Paul J, Trapani S, Louet M, Sounier R, Déméné H, Granier S, Bron P, Mouillac B. Cryo-electron microscopy structure of the antidiuretic hormone arginine-vasopressin V2 receptor signaling complex. SCIENCE ADVANCES 2021; 7:7/21/eabg5628. [PMID: 34020960 PMCID: PMC8139594 DOI: 10.1126/sciadv.abg5628] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 04/01/2021] [Indexed: 05/08/2023]
Abstract
The antidiuretic hormone arginine-vasopressin (AVP) forms a signaling complex with the V2 receptor (V2R) and the Gs protein, promoting kidney water reabsorption. Molecular mechanisms underlying activation of this critical G protein-coupled receptor (GPCR) signaling system are still unknown. To fill this gap of knowledge, we report here the cryo-electron microscopy structure of the AVP-V2R-Gs complex. Single-particle analysis revealed the presence of three different states. The two best maps were combined with computational and nuclear magnetic resonance spectroscopy constraints to reconstruct two structures of the ternary complex. These structures differ in AVP and Gs binding modes. They reveal an original receptor-Gs interface in which the Gαs subunit penetrates deep into the active V2R. The structures help to explain how V2R R137H or R137L/C variants can lead to two severe genetic diseases. Our study provides important structural insights into the function of this clinically relevant GPCR signaling complex.
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Affiliation(s)
- Julien Bous
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier cedex 5, France
- Centre de Biochimie Structurale, Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France
| | - Hélène Orcel
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier cedex 5, France
| | - Nicolas Floquet
- Institut des Biomolécules Max Mousseron, Université de Montpellier, CNRS, ENSCM, 34093 Montpellier cedex 5, France
| | - Cédric Leyrat
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier cedex 5, France
| | - Joséphine Lai-Kee-Him
- Centre de Biochimie Structurale, Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France
| | - Gérald Gaibelet
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier cedex 5, France
| | - Aurélie Ancelin
- Centre de Biochimie Structurale, Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France
| | - Julie Saint-Paul
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier cedex 5, France
| | - Stefano Trapani
- Centre de Biochimie Structurale, Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France
| | - Maxime Louet
- Institut des Biomolécules Max Mousseron, Université de Montpellier, CNRS, ENSCM, 34093 Montpellier cedex 5, France
| | - Rémy Sounier
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier cedex 5, France
| | - Hélène Déméné
- Centre de Biochimie Structurale, Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France
| | - Sébastien Granier
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier cedex 5, France.
| | - Patrick Bron
- Centre de Biochimie Structurale, Université de Montpellier, CNRS, INSERM, 34090 Montpellier, France.
| | - Bernard Mouillac
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier cedex 5, France.
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Structural studies of phosphorylation-dependent interactions between the V2R receptor and arrestin-2. Nat Commun 2021; 12:2396. [PMID: 33888704 PMCID: PMC8062632 DOI: 10.1038/s41467-021-22731-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/18/2021] [Indexed: 12/21/2022] Open
Abstract
Arrestins recognize different receptor phosphorylation patterns and convert this information to selective arrestin functions to expand the functional diversity of the G protein-coupled receptor (GPCR) superfamilies. However, the principles governing arrestin-phospho-receptor interactions, as well as the contribution of each single phospho-interaction to selective arrestin structural and functional states, are undefined. Here, we determined the crystal structures of arrestin2 in complex with four different phosphopeptides derived from the vasopressin receptor-2 (V2R) C-tail. A comparison of these four crystal structures with previously solved Arrestin2 structures demonstrated that a single phospho-interaction change results in measurable conformational changes at remote sites in the complex. This conformational bias introduced by specific phosphorylation patterns was further inspected by FRET and 1H NMR spectrum analysis facilitated via genetic code expansion. Moreover, an interdependent phospho-binding mechanism of phospho-receptor-arrestin interactions between different phospho-interaction sites was unexpectedly revealed. Taken together, our results provide evidence showing that phospho-interaction changes at different arrestin sites can elicit changes in affinity and structural states at remote sites, which correlate with selective arrestin functions. The interaction between a GPCR, such as the vasopressin receptor-2 (V2R), and arrestin depends on the receptors’ phosphorylation pattern. Here authors use FRET and NMR to analyze the phosphorylation patterns of the V2R-arrestin complex and show that phospho-interactions are the key determinants of selective arrestin conformational states and correlated functions.
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Franklin JM, Broseguini de Souza RK, Carrasco GA. Cannabinoid 2 receptors regulate dopamine 2 receptor expression by a beta-arrestin 2 and GRK5-dependent mechanism in neuronal cells. Neurosci Lett 2021; 753:135883. [PMID: 33838258 DOI: 10.1016/j.neulet.2021.135883] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 02/25/2021] [Accepted: 04/01/2021] [Indexed: 11/16/2022]
Abstract
We have previously reported that the repeated exposure to cannabinoids upregulates and enhances the activity of serotonin 2A (5-HT2A) and dopamine 2 (D2) receptors and facilitates the formation of D2-5-HT2A receptor heterodimers in the rat prefrontal cortex and two neuronal cell lines. Because the repeated exposure to cannabinoids has been associated with adverse neuropsychiatric disorders, this study investigated the mechanisms that underly the cannabinoid-mediated regulation of D2 receptor expression in a neuronal cell model, CLU213 cells. We initially tested the effects of repeated exposure (72 h) to a non-selective cannabinoid agonist (1 nM CP55940), a selective CB1 receptor agonist (15 nM ACEA), or a selective CB2 receptor drug (1 nM GP1a) on the expression of postsynaptic D2 (D2L) receptors in CLU213 cells. Repeated CP55940, GP1a, or ACEA treatments significantly increased D2L receptor protein levels (99 % ± 7%, 30 % ± 7%, and 39 % ± 5% increases compared with control levels, respectively). Repeated exposure to both GP1a and ACEA increased D2L receptor protein levels by 73 % ± 8%. Interestingly, CP55940 and GP1a, but not ACEA, upregulated D2 mRNA. Using cells that were stably transfected with short-hairpin RNA (shRNA) lentiviral particles targeting CB2 receptors, G protein-coupled receptor kinase 5 (GRK5), and β-arrestin 2, we found that CB2 receptors regulated D2 expression through a mechanism that is dependent on GRK5, β-arrestin 2, and extracellular signal-related kinase (ERK)1/2. We also found that repeated exposure to either ACEA or GP1a selectively stimulated the protein and mRNA expression of GRK proteins. ACEA significantly upregulated GRK2 proteins, whereas GP1a upregulated GRK5 protein expression. Our results identified mechanisms associated with the upregulation of D2 receptors in neuronal cells after the repeated exposure to cannabinoids. These data can shed light on the mechanisms that can be targeted to prevent potential adverse effects, while simultaneously determining the therapeutic benefits of cannabinoids.
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Affiliation(s)
- Jade M Franklin
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Kansas, United States
| | | | - Gonzalo A Carrasco
- Department of Biomedical Sciences, Copper Medical School of Rowan University, New Jersey, United States; Rowan University Institute for Cannabis Research, Policy, & Workforce Development, New Jersey, United States.
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Chaudhary PK, Kim S. The GRKs Reactome: Role in Cell Biology and Pathology. Int J Mol Sci 2021; 22:ijms22073375. [PMID: 33806057 PMCID: PMC8036551 DOI: 10.3390/ijms22073375] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/21/2021] [Accepted: 03/22/2021] [Indexed: 02/06/2023] Open
Abstract
G protein-coupled receptor kinases (GRKs) are protein kinases that function in concert with arrestins in the regulation of a diverse class of G protein-coupled receptors (GPCRs) signaling. Although GRKs and arrestins are key participants in the regulation of GPCR cascades, the complex regulatory mechanisms of GRK expression, its alternation, and their function are not thoroughly understood. Several studies together with the work from our lab in recent years have revealed the critical role of these kinases in various physiological and pathophysiological processes, including cardiovascular biology, inflammation and immunity, neurodegeneration, thrombosis, and hemostasis. A comprehensive understanding of the mechanisms underlying functional interactions with multiple receptor proteins and how these interactions take part in the development of various pathobiological processes may give rise to novel diagnostic and therapeutic strategies. In this review, we summarize the current research linking the role of GRKs to various aspects of cell biology, pathology, and therapeutics, with a particular focus on thrombosis and hemostasis.
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Aydin Y, Coin I. Biochemical insights into structure and function of arrestins. FEBS J 2021; 288:2529-2549. [DOI: 10.1111/febs.15811] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/26/2021] [Accepted: 03/09/2021] [Indexed: 12/13/2022]
Affiliation(s)
- Yasmin Aydin
- Institute of Biochemistry Faculty of Life Sciences University of Leipzig Germany
| | - Irene Coin
- Institute of Biochemistry Faculty of Life Sciences University of Leipzig Germany
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38
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Receptor-Arrestin Interactions: The GPCR Perspective. Biomolecules 2021; 11:biom11020218. [PMID: 33557162 PMCID: PMC7913897 DOI: 10.3390/biom11020218] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/25/2021] [Accepted: 02/01/2021] [Indexed: 02/06/2023] Open
Abstract
Arrestins are a small family of four proteins in most vertebrates that bind hundreds of different G protein-coupled receptors (GPCRs). Arrestin binding to a GPCR has at least three functions: precluding further receptor coupling to G proteins, facilitating receptor internalization, and initiating distinct arrestin-mediated signaling. The molecular mechanism of arrestin–GPCR interactions has been extensively studied and discussed from the “arrestin perspective”, focusing on the roles of arrestin elements in receptor binding. Here, we discuss this phenomenon from the “receptor perspective”, focusing on the receptor elements involved in arrestin binding and emphasizing existing gaps in our knowledge that need to be filled. It is vitally important to understand the role of receptor elements in arrestin activation and how the interaction of each of these elements with arrestin contributes to the latter’s transition to the high-affinity binding state. A more precise knowledge of the molecular mechanisms of arrestin activation is needed to enable the construction of arrestin mutants with desired functional characteristics.
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Zariñán T, Mayorga J, Jardón-Valadez E, Gutiérrez-Sagal R, Maravillas-Montero JL, Mejía-Domínguez NR, Martínez-Luis I, Yacini-Torres OG, Cravioto MDC, Reiter E, Ulloa-Aguirre A. A Novel Mutation in the FSH Receptor (I423T) Affecting Receptor Activation and Leading to Primary Ovarian Failure. J Clin Endocrinol Metab 2021; 106:e534-e550. [PMID: 33119067 DOI: 10.1210/clinem/dgaa782] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Indexed: 12/13/2022]
Abstract
CONTEXT Follicle-stimulating hormone (FSH) plays an essential role in gonadal function. Loss-of-function mutations in the follicle-stimulating hormone receptor (FSHR) are an infrequent cause of primary ovarian failure. OBJECTIVE To analyze the molecular physiopathogenesis of a novel mutation in the FSHR identified in a woman with primary ovarian failure, employing in vitro and in silico approaches, and to compare the features of this dysfunctional receptor with those shown by the trafficking-defective D408Y FSHR mutant. METHODS Sanger sequencing of the FSHR cDNA was applied to identify the novel mutation. FSH-stimulated cyclic adenosine monophosphate (cAMP) production, ERK1/2 phosphorylation, and desensitization were tested in HEK293 cells. Receptor expression was analyzed by immunoblotting, receptor-binding assays, and flow cytometry. Molecular dynamics simulations were performed to determine the in silico behavior of the mutant FSHRs. RESULTS A novel missense mutation (I423T) in the second transmembrane domain of the FSHR was identified in a woman with normal pubertal development but primary amenorrhea. The I423T mutation slightly impaired plasma membrane expression of the mature form of the receptor and severely impacted on cAMP/protein kinase A signaling but much less on β-arrestin-dependent ERK1/2 phosphorylation. Meanwhile, the D408Y mutation severely affected membrane expression, with most of the FSH receptor located intracellularly, and both signal readouts tested. Molecular dynamics simulations revealed important functional disruptions in both mutant FSHRs, mainly the loss of interhelical connectivity in the D408Y FSHR. CONCLUSIONS Concurrently, these data indicate that conformational differences during the inactive and active states account for the distinct expression levels, differential signaling, and phenotypic expression of the I423T and D408Y mutant FSHRs.
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Affiliation(s)
- Teresa Zariñán
- Red de Apoyo a la Investigación, National University of Mexico-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Julio Mayorga
- Department of Reproductive Biology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Eduardo Jardón-Valadez
- Departamento de Recursos de la Tierra, Universidad Autónoma Metropolitana, Unidad Lerma, Lerma, Edo. de Mexico, Mexico
| | - Rubén Gutiérrez-Sagal
- Red de Apoyo a la Investigación, National University of Mexico-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - José Luis Maravillas-Montero
- Red de Apoyo a la Investigación, National University of Mexico-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Nancy R Mejía-Domínguez
- Red de Apoyo a la Investigación, National University of Mexico-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Iván Martínez-Luis
- Red de Apoyo a la Investigación, National University of Mexico-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Omar G Yacini-Torres
- Red de Apoyo a la Investigación, National University of Mexico-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Ma-Del-Carmen Cravioto
- Department of Reproductive Biology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Eric Reiter
- Physiologie de la Reproduction et des Comportements (PRC), Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS), Université de Tours, Tours, France
| | - Alfredo Ulloa-Aguirre
- Red de Apoyo a la Investigación, National University of Mexico-Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
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40
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Dissecting the structural features of β-arrestins as multifunctional proteins. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2021; 1869:140603. [PMID: 33421644 DOI: 10.1016/j.bbapap.2021.140603] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/21/2020] [Accepted: 01/04/2021] [Indexed: 02/08/2023]
Abstract
β-arrestins bind active G protein-coupled receptors (GPCRs) and play a crucial role in receptor desensitization and internalization. The classical paradigm of arrestin function has been expanded with the identification of many non-receptor-binding partners, which indicated the multifunctional role of β-arrestins in cellular functions. To elucidate the molecular mechanism of β-arrestin-mediated signaling, the structural features of β-arrestins were investigated using X-ray crystallography and cryogenic electron microscopy (cryo-EM). However, the intrinsic conformational flexibility of β-arrestins hampers the elucidation of structural interactions between β-arrestins and their binding partners using conventional structure determination tools. Therefore, structural information obtained using complementary structure analysis techniques would be necessary in combination with X-ray crystallography and cryo-EM data. In this review, we describe how β-arrestins interact with their binding partners from a structural point of view, as elucidated by both traditional methods (X-ray crystallography and cryo-EM) and complementary structure analysis techniques.
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Gurevich EV, Gurevich VV. GRKs as Modulators of Neurotransmitter Receptors. Cells 2020; 10:cells10010052. [PMID: 33396400 PMCID: PMC7823573 DOI: 10.3390/cells10010052] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 12/23/2020] [Accepted: 12/30/2020] [Indexed: 01/08/2023] Open
Abstract
Many receptors for neurotransmitters, such as dopamine, norepinephrine, acetylcholine, and neuropeptides, belong to the superfamily of G protein-coupled receptors (GPCRs). A general model posits that GPCRs undergo two-step homologous desensitization: the active receptor is phosphorylated by kinases of the G protein-coupled receptor kinase (GRK) family, whereupon arrestin proteins specifically bind active phosphorylated receptors, shutting down G protein-mediated signaling, facilitating receptor internalization, and initiating distinct signaling pathways via arrestin-based scaffolding. Here, we review the mechanisms of GRK-dependent regulation of neurotransmitter receptors, focusing on the diverse modes of GRK-mediated phosphorylation of receptor subtypes. The immediate signaling consequences of GRK-mediated receptor phosphorylation, such as arrestin recruitment, desensitization, and internalization/resensitization, are equally diverse, depending not only on the receptor subtype but also on phosphorylation by GRKs of select receptor residues. We discuss the signaling outcome as well as the biological and behavioral consequences of the GRK-dependent phosphorylation of neurotransmitter receptors where known.
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Calebiro D, Koszegi Z, Lanoiselée Y, Miljus T, O'Brien S. G protein-coupled receptor-G protein interactions: a single-molecule perspective. Physiol Rev 2020; 101:857-906. [PMID: 33331229 DOI: 10.1152/physrev.00021.2020] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
G protein-coupled receptors (GPCRs) regulate many cellular and physiological processes, responding to a diverse range of extracellular stimuli including hormones, neurotransmitters, odorants, and light. Decades of biochemical and pharmacological studies have provided fundamental insights into the mechanisms of GPCR signaling. Thanks to recent advances in structural biology, we now possess an atomistic understanding of receptor activation and G protein coupling. However, how GPCRs and G proteins interact in living cells to confer signaling efficiency and specificity remains insufficiently understood. The development of advanced optical methods, including single-molecule microscopy, has provided the means to study receptors and G proteins in living cells with unprecedented spatio-temporal resolution. The results of these studies reveal an unexpected level of complexity, whereby GPCRs undergo transient interactions among themselves as well as with G proteins and structural elements of the plasma membrane to form short-lived signaling nanodomains that likely confer both rapidity and specificity to GPCR signaling. These findings may provide new strategies to pharmaceutically modulate GPCR function, which might eventually pave the way to innovative drugs for common diseases such as diabetes or heart failure.
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Affiliation(s)
- Davide Calebiro
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Zsombor Koszegi
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Yann Lanoiselée
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Tamara Miljus
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Shannon O'Brien
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
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43
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Semesta KM, Tian R, Kampmann M, von Zastrow M, Tsvetanova NG. A high-throughput CRISPR interference screen for dissecting functional regulators of GPCR/cAMP signaling. PLoS Genet 2020; 16:e1009103. [PMID: 33052901 PMCID: PMC7588078 DOI: 10.1371/journal.pgen.1009103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 10/26/2020] [Accepted: 09/08/2020] [Indexed: 12/27/2022] Open
Abstract
G protein-coupled receptors (GPCRs) allow cells to respond to chemical and sensory stimuli through generation of second messengers, such as cyclic AMP (cAMP), which in turn mediate a myriad of processes, including cell survival, proliferation, and differentiation. In order to gain deeper insights into the complex biology and physiology of these key cellular pathways, it is critical to be able to globally map the molecular factors that shape cascade function. Yet, to this date, efforts to systematically identify regulators of GPCR/cAMP signaling have been lacking. Here, we combined genome-wide screening based on CRISPR interference with a novel sortable transcriptional reporter that provides robust readout for cAMP signaling, and carried out a functional screen for regulators of the pathway. Due to the sortable nature of the platform, we were able to assay regulators with strong and moderate phenotypes by analyzing sgRNA distribution among three fractions with distinct reporter expression. We identified 45 regulators with strong and 50 regulators with moderate phenotypes not previously known to be involved in cAMP signaling. In follow-up experiments, we validated the functional effects of seven newly discovered mediators (NUP93, PRIM1, RUVBL1, PKMYT1, TP53, SF3A2, and HRAS), and showed that they control distinct steps of the pathway. Thus, our study provides proof of principle that the screening platform can be applied successfully to identify bona fide regulators of GPCR/second messenger cascades in an unbiased and high-throughput manner, and illuminates the remarkable functional diversity among GPCR regulators.
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Affiliation(s)
- Khairunnisa Mentari Semesta
- Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, United States of America
| | - Ruilin Tian
- Institute for Neurodegenerative Diseases, Department of Biochemistry and Biophysics, University of California, San Francisco, California, United States of America
- Chen-Zuckerberg Biohub, San Francisco, California, United States of America
- Biophysics Graduate Program, University of California, San Francisco, California, United States of America
| | - Martin Kampmann
- Institute for Neurodegenerative Diseases, Department of Biochemistry and Biophysics, University of California, San Francisco, California, United States of America
- Chen-Zuckerberg Biohub, San Francisco, California, United States of America
| | - Mark von Zastrow
- Department of Psychiatry, University of California, San Francisco, California, United States of America
- Department of Cellular & Molecular Pharmacology, University of California, San Francisco, California, United States of America
| | - Nikoleta G. Tsvetanova
- Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina, United States of America
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Babwah AV. The wonderful and masterful G protein-coupled receptor (GPCR): A focus on signaling mechanisms and the neuroendocrine control of fertility. Mol Cell Endocrinol 2020; 515:110886. [PMID: 32574585 DOI: 10.1016/j.mce.2020.110886] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 05/08/2020] [Accepted: 05/20/2020] [Indexed: 12/18/2022]
Abstract
Human GnRH deficiency, both clinically and genetically, is a heterogeneous disorder comprising of congenital GnRH deficiency with anosmia (Kallmann syndrome), or with normal olfaction [normosmic idiopathic hypogonadotropic hypogonadism (IHH)], and adult-onset hypogonadotropic hypogonadism. Our understanding of the neural mechanisms underlying GnRH secretion and GnRH signaling continues to increase at a rapid rate and strikingly, the heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs) continue to emerge as essential players in these processes. GPCRs were once viewed as binary on-off switches, where in the "on" state they are bound to their Gα protein, but now we understand that view is overly simplistic and does not adequately characterize GPCRs. Instead, GPCRs have emerged as masterful signaling molecules exploiting different physical conformational states of itself to elicit an array of downstream signaling events via their G proteins and the β-arrestins. The "one receptor-multiple signaling conformations" model is likely an evolved strategy that can be used to our advantage as researchers have shown that targeting specific receptor conformations via biased ligands is proving to be a powerful tool in the effective treatment of human diseases. Can biased ligands be used to selectively modulate signaling by GPCR regulators of the neuroendocrine axis in the treatment of IHH? As discussed in this review, the grand possibility exists. However, while we are still very far from developing these treatments, this exciting likelihood can happen through a much greater mechanistic understanding of how GPCRs signal within the cell.
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Affiliation(s)
- Andy V Babwah
- Department of Pediatrics, Laboratory of Human Growth and Reproductive Development, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States; Child Health Institute of New Jersey, New Brunswick, NJ, United States.
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45
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Baidya M, Kumari P, Dwivedi-Agnihotri H, Pandey S, Chaturvedi M, Stepniewski TM, Kawakami K, Cao Y, Laporte SA, Selent J, Inoue A, Shukla AK. Key phosphorylation sites in GPCRs orchestrate the contribution of β-Arrestin 1 in ERK1/2 activation. EMBO Rep 2020; 21:e49886. [PMID: 32715625 DOI: 10.15252/embr.201949886] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 06/21/2020] [Accepted: 06/24/2020] [Indexed: 01/08/2023] Open
Abstract
β-arrestins (βarrs) are key regulators of G protein-coupled receptor (GPCR) signaling and trafficking, and their knockdown typically leads to a decrease in agonist-induced ERK1/2 MAP kinase activation. Interestingly, for some GPCRs, knockdown of βarr1 augments agonist-induced ERK1/2 phosphorylation although a mechanistic basis for this intriguing phenomenon is unclear. Here, we use selected GPCRs to explore a possible correlation between the spatial positioning of receptor phosphorylation sites and the contribution of βarr1 in ERK1/2 activation. We discover that engineering a spatially positioned double-phosphorylation-site cluster in the bradykinin receptor (B2 R), analogous to that present in the vasopressin receptor (V2 R), reverses the contribution of βarr1 in ERK1/2 activation from inhibitory to promotive. An intrabody sensor suggests a conformational mechanism for this role reversal of βarr1, and molecular dynamics simulation reveals a bifurcated salt bridge between this double-phosphorylation site cluster and Lys294 in the lariat loop of βarr1, which directs the orientation of the lariat loop. Our findings provide novel insights into the opposite roles of βarr1 in ERK1/2 activation for different GPCRs with a direct relevance to biased agonism and novel therapeutics.
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Affiliation(s)
- Mithu Baidya
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | - Punita Kumari
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | | | - Shubhi Pandey
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | - Madhu Chaturvedi
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | - Tomasz Maciej Stepniewski
- Research Programme on Biomedical Informatics (GRIB), Department of Experimental and Health Sciences of Pompeu, Fabra University (UPF)-Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain.,Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Kouki Kawakami
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Yubo Cao
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada
| | - Stéphane A Laporte
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada.,Department of Medicine, McGill University Health Center, McGill University, Montréal, QC, Canada
| | - Jana Selent
- Research Programme on Biomedical Informatics (GRIB), Department of Experimental and Health Sciences of Pompeu, Fabra University (UPF)-Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Arun K Shukla
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
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46
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Kaya AI, Perry NA, Gurevich VV, Iverson TM. Phosphorylation barcode-dependent signal bias of the dopamine D1 receptor. Proc Natl Acad Sci U S A 2020; 117:14139-14149. [PMID: 32503917 PMCID: PMC7321966 DOI: 10.1073/pnas.1918736117] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Agonist-activated G protein-coupled receptors (GPCRs) must correctly select from hundreds of potential downstream signaling cascades and effectors. To accomplish this, GPCRs first bind to an intermediary signaling protein, such as G protein or arrestin. These intermediaries initiate signaling cascades that promote the activity of different effectors, including several protein kinases. The relative roles of G proteins versus arrestins in initiating and directing signaling is hotly debated, and it remains unclear how the correct final signaling pathway is chosen given the ready availability of protein partners. Here, we begin to deconvolute the process of signal bias from the dopamine D1 receptor (D1R) by exploring factors that promote the activation of ERK1/2 or Src, the kinases that lead to cell growth and proliferation. We found that ERK1/2 activation involves both arrestin and Gαs, while Src activation depends solely on arrestin. Interestingly, we found that the phosphorylation pattern influences both arrestin and Gαs coupling, suggesting an additional way the cells regulate G protein signaling. The phosphorylation sites in the D1R intracellular loop 3 are particularly important for directing the binding of G protein versus arrestin and for selecting between the activation of ERK1/2 and Src. Collectively, these studies correlate functional outcomes with a physical basis for signaling bias and provide fundamental information on how GPCR signaling is directed.
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Affiliation(s)
- Ali I Kaya
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
| | - Nicole A Perry
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
| | | | - T M Iverson
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232;
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232
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47
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Biased GPCR signaling: Possible mechanisms and inherent limitations. Pharmacol Ther 2020; 211:107540. [PMID: 32201315 DOI: 10.1016/j.pharmthera.2020.107540] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 03/17/2020] [Indexed: 02/06/2023]
Abstract
G protein-coupled receptors (GPCRs) are targeted by about a third of clinically used drugs. Many GPCRs couple to more than one type of heterotrimeric G proteins, become phosphorylated by any of several different GRKs, and then bind one or more types of arrestin. Thus, classical therapeutically active drugs simultaneously initiate several branches of signaling, some of which are beneficial, whereas others result in unwanted on-target side effects. The development of novel compounds to selectively channel the signaling into the desired direction has the potential to become a breakthrough in health care. However, there are natural and technological hurdles that must be overcome. The fact that most GPCRs are subject to homologous desensitization, where the active receptor couples to G proteins, is phosphorylated by GRKs, and then binds arrestins, suggest that in most cases the GPCR conformations that facilitate their interactions with these three classes of binding partners significantly overlap. Thus, while partner-specific conformations might exist, they are likely low-probability states. GPCRs are inherently flexible, which suggests that complete bias is highly unlikely to be feasible: in the conformational ensemble induced by any ligand, there would be some conformations facilitating receptor coupling to unwanted partners. Things are further complicated by the fact that virtually every cell expresses numerous G proteins, several GRK subtypes, and two non-visual arrestins with distinct signaling capabilities. Finally, novel screening methods for measuring ligand bias must be devised, as the existing methods are not specific for one particular branch of signaling.
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Senatorov IS, Cheshmehkani A, Burns RN, Singh K, Moniri NH. Carboxy-Terminal Phosphoregulation of the Long Splice Isoform of Free-Fatty Acid Receptor-4 Mediates β-Arrestin Recruitment and Signaling to ERK1/2. Mol Pharmacol 2020; 97:304-313. [PMID: 32132133 DOI: 10.1124/mol.119.117697] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 01/31/2020] [Indexed: 12/13/2022] Open
Abstract
Free-fatty acid receptor-4 (FFA4), previously termed GPR120, is a G protein-coupled receptor (GPCR) for medium and long-chained fatty acids, agonism of which can regulate a myriad of metabolic, sensory, inflammatory, and proliferatory signals. Two alternative splice isoforms of FFA4 exist that differ by the presence of an additional 16 amino acids in the longer (FFA4-L) transcript, which has been suggested to be an intrinsically β-arrestin-biased GPCR. Although the shorter isoform (FFA4-S) has been studied more extensively, very little is known about mechanisms of regulation or signaling of the longer isoform. Because β-arrestin recruitment is dependent on receptor phosphorylation, in the current study, we used the endogenous agonist docosahexaenoic acid (DHA) to examine the mechanisms of FFA4-L phosphorylation, as well as DHA-dependent β-arrestin recruitment and DHA-dependent extracellular-signal regulated kinase-1/2 (ERK1/2) signaling in human embryonic kidney 293 cells. Our results reveal differences in basal phosphorylation of the two FFA4 isoforms, and we show that DHA-mediated phosphorylation of FFA4-L is primarily regulated by G protein-coupled receptor kinase 6, whereas protein kinase-C can also contribute to agonist-induced and heterologous phosphorylation. Moreover, our data demonstrate that FFA4-L phosphorylation occurs on the distal C terminus and is directly responsible for recruitment and interactions with β-arrestin-2. Finally, using CRISPR/Cas9 genome-edited cells, our data reveal that unlike FFA4-S, the longer isoform is unable to facilitate phosphorylation of ERK1/2 in cells that are devoid of β-arrestin-1/2. Together, these results are the first to demonstrate phosphoregulation of FFA4-L as well as the effects of loss of phosphorylation sites on β-arrestin recruitment and ERK1/2 activation. SIGNIFICANCE STATEMENT: Free-fatty acid receptor-4 (FFA4) is a cell-surface G protein-coupled receptor for medium and long-chained fatty acids that can be expressed as distinct short (FFA4-S) or long (FFA4-L) isoforms. Although much is known about FFA4-S, the longer isoform remains virtually unstudied. Here, we reveal the mechanisms of docosahexaenoic acid-induced phosphorylation of FFA4-L and subsequent β-arrestin-2 recruitment and extracellular-signal regulated kinase-1/2 activity.
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Affiliation(s)
- Ilya S Senatorov
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, Georgia
| | - Ameneh Cheshmehkani
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, Georgia
| | - Rebecca N Burns
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, Georgia
| | - Kirti Singh
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, Georgia
| | - Nader H Moniri
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, Georgia
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49
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Pietraszewska-Bogiel A, Joosen L, Chertkova AO, Goedhart J. Not So Dry After All: DRY Mutants of the AT1 A Receptor and H1 Receptor Can Induce G-Protein-Dependent Signaling. ACS OMEGA 2020; 5:2648-2659. [PMID: 32095688 PMCID: PMC7033670 DOI: 10.1021/acsomega.9b03146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/23/2020] [Indexed: 06/10/2023]
Abstract
G-protein-coupled receptors (GPCRs) are seven transmembrane spanning receptors that regulate a wide array of intracellular signaling cascades in response to various stimuli. To do so, they couple to different heterotrimeric G proteins and adaptor proteins, including arrestins. Importantly, arrestins were shown to regulate GPCR signaling through G proteins, as well as promote G protein-independent signaling events. Several research groups have reported successful isolation of exclusively G protein-dependent and arrestin-dependent signaling downstream of GPCR activation using biased agonists or receptor mutants incapable of coupling to either arrestins or G proteins. In the latter category, the DRY mutant of the angiotensin II type 1 receptor was extensively used to characterize the functional selectivity downstream of AT1AR. In an attempt to understand histamine 1 receptor signaling, we characterized the signaling capacity of the H1R DRY mutant in a panel of dynamic, live cell biosensor assays, including arrestin recruitment, heterotrimeric G protein activation, Ca2+ signaling, protein kinase C activity, GTP binding of RhoA, and activation of ERK1/2. Here, we show that both H1R DRY mutant and the AT1AR DRY mutant are capable of efficient activation of G protein-mediated signaling. Therefore, contrary to the common belief, they do not constitute suitable tools for the dissection of the arrestin-mediated, G protein-independent signaling downstream of these receptors.
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50
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Duerrauer L, Muratspahić E, Gattringer J, Keov P, Mendel HC, Pfleger KDG, Muttenthaler M, Gruber CW. I8-arachnotocin-an arthropod-derived G protein-biased ligand of the human vasopressin V 2 receptor. Sci Rep 2019; 9:19295. [PMID: 31848378 PMCID: PMC6917733 DOI: 10.1038/s41598-019-55675-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/28/2019] [Indexed: 12/14/2022] Open
Abstract
The neuropeptides oxytocin (OT) and vasopressin (VP) and their G protein-coupled receptors OTR, V1aR, V1bR, and V2R form an important and widely-distributed neuroendocrine signaling system. In mammals, this signaling system regulates water homeostasis, blood pressure, reproduction, as well as social behaviors such as pair bonding, trust and aggression. There exists high demand for ligands with differing pharmacological profiles to study the physiological and pathological functions of the individual receptor subtypes. Here, we present the pharmacological characterization of an arthropod (Metaseiulus occidentalis) OT/VP-like nonapeptide across the human OT/VP receptors. I8-arachnotocin is a full agonist with respect to second messenger signaling at human V2R (EC50 34 nM) and V1bR (EC50 1.2 µM), a partial agonist at OTR (EC50 790 nM), and a competitive antagonist at V1aR [pA2 6.25 (558 nM)]. Intriguingly, I8-arachnotocin activated the Gαs pathway of V2R without recruiting either β-arrestin-1 or β-arrestin-2. I8-arachnotocin might thus be a novel pharmacological tool to study the (patho)physiological relevance of β-arrestin-1 or -2 recruitment to the V2R. These findings furthermore highlight arthropods as a novel, vast and untapped source for the discovery of novel pharmacological probes and potential drug leads targeting neurohormone receptors.
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Affiliation(s)
- Leopold Duerrauer
- Institute of Pharmacology, Center for Pharmacology and Physiology, Medical University of Vienna, Vienna, Austria.,School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia.,Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Edin Muratspahić
- Institute of Pharmacology, Center for Pharmacology and Physiology, Medical University of Vienna, Vienna, Austria
| | - Jasmin Gattringer
- Institute of Pharmacology, Center for Pharmacology and Physiology, Medical University of Vienna, Vienna, Austria
| | - Peter Keov
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia.,Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Helen C Mendel
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Kevin D G Pfleger
- Centre for Medical Research, The University of Western Australia and Harry Perkins Institute of Medical Research, Nedlands, Western Australia, Australia
| | - Markus Muttenthaler
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia.,Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Christian W Gruber
- Institute of Pharmacology, Center for Pharmacology and Physiology, Medical University of Vienna, Vienna, Austria. .,School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia.
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