1
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Carruthers ER, Grimsey NL. Cannabinoid CB 2 receptor orthologues; in vitro function and perspectives for preclinical to clinical translation. Br J Pharmacol 2024; 181:2247-2269. [PMID: 37349984 DOI: 10.1111/bph.16172] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 05/01/2023] [Accepted: 05/22/2023] [Indexed: 06/24/2023] Open
Abstract
Cannabinoid CB2 receptor agonists are in development as therapeutic agents, including for immune modulation and pain relief. Despite promising results in rodent preclinical studies, efficacy in human clinical trials has been marginal to date. Fundamental differences in ligand engagement and signalling responses between the human CB2 receptor and preclinical model species orthologues may contribute to mismatches in functional outcomes. This is a tangible possibility for the CB2 receptor in that there is a relatively large degree of primary amino acid sequence divergence between human and rodent. Here, we summarise CB2 receptor gene and protein structure, assess comparative molecular pharmacology between CB2 receptor orthologues, and review the current status of preclinical to clinical translation for drugs targeted at the CB2 receptor, focusing on comparisons between human, mouse and rat receptors. We hope that raising wider awareness of, and proposing strategies to address, this additional challenge in drug development will assist in ongoing efforts toward successful therapeutic translation of drugs targeted at the CB2 receptor. LINKED ARTICLES: This article is part of a themed issue Therapeutic Targeting of G Protein-Coupled Receptors: hot topics from the Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists 2021 Virtual Annual Scientific Meeting. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.14/issuetoc.
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Affiliation(s)
- Emma R Carruthers
- Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
| | - 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
- Centre for Brain Research, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
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2
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Xu X, Wu G. Protocol to visualize and quantify the COPII concentration and anterograde transport of nascent G protein-coupled receptors. STAR Protoc 2024; 5:102955. [PMID: 38489271 PMCID: PMC10951583 DOI: 10.1016/j.xpro.2024.102955] [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: 01/02/2024] [Revised: 01/31/2024] [Accepted: 02/28/2024] [Indexed: 03/17/2024] Open
Abstract
Here, we present a protocol for visualization and quantification of the recruitment of newly synthesized G protein-coupled receptors (GPCRs) to coat protein complex II vesicles and GPCR transport from the endoplasmic reticulum through the Golgi to the cell surface in the retention using the selective hooks assay. We describe steps for plasmid construction, cell transfection, transport synchronization, confocal microscope imaging, and quantification. This protocol is also applicable for studying the transport of non-GPCR cargoes. For complete details on the use and execution of this protocol, please refer to Xu et al.1,2.
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Affiliation(s)
- Xin Xu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA.
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA.
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3
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Xu X, Huang W, Bryant CN, Dong Z, Li H, Wu G. The ufmylation cascade controls COPII recruitment, anterograde transport, and sorting of nascent GPCRs at ER. SCIENCE ADVANCES 2024; 10:eadm9216. [PMID: 38905340 PMCID: PMC11192079 DOI: 10.1126/sciadv.adm9216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 05/14/2024] [Indexed: 06/23/2024]
Abstract
Ufmylation is implicated in multiple cellular processes, but little is known about its functions and regulation in protein trafficking. Here, we demonstrate that the genetic depletion of core components of the ufmylation cascade, including ubiquitin-fold modifier 1 (UFM1), UFM1 activation enzyme 5, UFM1-specific ligase 1 (UFL1), UFM1-specific protease 2, and UFM1-binding protein 1 (UFBP1) each markedly inhibits the endoplasmic reticulum (ER)-Golgi transport, surface delivery, and recruitment to COPII vesicles of a subset of G protein-coupled receptors (GPCRs) and UFBP1's function partially relies on UFM1 conjugation. We also show that UFBP1 and UFL1 interact with GPCRs and UFBP1 localizes at COPII vesicles coated with specific Sec24 isoforms. Furthermore, the UFBP1/UFL1-binding domain identified in the receptors effectively converts non-GPCR protein transport into the ufmylation-dependent pathway. Collectively, these data reveal important functions for the ufmylation system in GPCR recruitment to COPII vesicles, biosynthetic transport, and sorting at ER via UFBP1 ufmylation and interaction directly.
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Affiliation(s)
- Xin Xu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Wei Huang
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Christian N. Bryant
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Zheng Dong
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Honglin Li
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA, USA
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4
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Xu X, Qiu L, Zhang M, Wu G. Segregation of nascent GPCRs in the ER-to-Golgi transport by CCHCR1 via direct interaction. J Cell Sci 2024; 137:jcs261685. [PMID: 38230433 PMCID: PMC10912811 DOI: 10.1242/jcs.261685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 01/03/2024] [Indexed: 01/18/2024] Open
Abstract
G protein-coupled receptors (GPCRs) constitute the largest superfamily of cell surface signaling proteins that share a common structural topology. When compared with agonist-induced internalization, how GPCRs are sorted and delivered to functional destinations after synthesis in the endoplasmic reticulum (ER) is much less well understood. Here, we demonstrate that depletion of coiled-coil α-helical rod protein 1 (CCHCR1) by siRNA and CRISPR-Cas9 significantly inhibits surface expression and signaling of α2A-adrenergic receptor (α2A-AR; also known as ADRA2A), without affecting α2B-AR. Further studies show that CCHCR1 depletion specifically impedes α2A-AR export from the ER to the Golgi, but not from the Golgi to the surface. We also demonstrate that CCHCR1 selectively interacts with α2A-AR. The interaction is mediated through multiple domains of both proteins and is ionic in nature. Moreover, mutating CCHCR1-binding motifs significantly attenuates ER-to-Golgi export, surface expression and signaling of α2A-AR. Collectively, these data reveal a novel function for CCHCR1 in intracellular protein trafficking, indicate that closely related GPCRs can be sorted into distinct ER-to-Golgi transport routes by CCHCR1 via direct interaction, and provide important insights into segregation and anterograde delivery of nascent GPCR members.
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Affiliation(s)
- Xin Xu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Lifen Qiu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Maoxiang Zhang
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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5
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Xu X, Lambert NA, Wu G. Sequence-directed concentration of G protein-coupled receptors in COPII vesicles. iScience 2023; 26:107969. [PMID: 37810244 PMCID: PMC10551652 DOI: 10.1016/j.isci.2023.107969] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/02/2023] [Accepted: 09/15/2023] [Indexed: 10/10/2023] Open
Abstract
G protein-coupled receptors (GPCRs) constitute the largest superfamily of plasma membrane signaling proteins. However, virtually nothing is known about their recruitment to COPII vesicles for forward delivery after synthesis in the endoplasmic reticulum (ER). Here, we demonstrate that some GPCRs are highly concentrated at ER exit sites (ERES) before COPII budding. Angiotensin II type 2 receptor (AT2R) and CXCR4 concentration are directed by a di-acidic motif and a 9-residue domain, respectively, and these motifs also control receptor ER-Golgi traffic. We further show that AT2R interacts with Sar1 GTPase and that distinct GPCRs have different ER-Golgi transport rates via COPII which is independent of their concentration at ERES. Collectively, these data demonstrate that GPCRs can be actively captured by COPII via specific motifs and direct interaction with COPII components that in turn affects their export dynamics, and provide important insights into COPII targeting and forward trafficking of nascent GPCRs.
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Affiliation(s)
- Xin Xu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Nevin A. Lambert
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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6
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Wu KC, Condon ND, Hill TA, Reid RC, Fairlie DP, Lim J. Ras-Related Protein Rab5a Regulates Complement C5a Receptor Trafficking, Chemotaxis, and Chemokine Secretion in Human Macrophages. J Innate Immun 2023; 15:468-484. [PMID: 36882040 PMCID: PMC10105068 DOI: 10.1159/000530012] [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: 10/12/2022] [Accepted: 03/01/2023] [Indexed: 03/09/2023] Open
Abstract
Complement activation and Rab GTPase trafficking are commonly observed in inflammatory responses. Recruitment of innate immune cells to sites of infection or injury and secretion of inflammatory chemokines are promoted by complement component 5a (C5a) that activates the cell surface protein C5a receptor1 (C5aR1). Persistent activation can lead to a myriad of inflammatory and autoimmune diseases. Here, we demonstrate that the mechanism of C5a induced chemotaxis of human monocyte-derived macrophages (HMDMs) and their secretion of inflammatory chemokines are controlled by Rab5a. We find that C5a activation of the G protein coupled receptor C5aR1 expressed on the surface of HMDMs, recruits β-arrestin2 via Rab5a trafficking, then activates downstream phosphatidylinositol 3-kinase (PI3K)/Akt signaling that culminates in chemotaxis and secretion of pro-inflammatory chemokines from HMDMs. High-resolution lattice light-sheet microscopy on live cells showed that C5a activates C5aR1-GFP internalization and colocalization with Rab5a-tdTomato but not with dominant negative mutant Rab5a-S34N-tdTomato in HEK293 cells. We found that Rab5a is significantly upregulated in differentiated HMDMs and internalization of C5aR1 is dependent on Rab5a. Interestingly, while knockdown of Rab5a inhibited C5aR1-mediated Akt phosphorylation, it did not affect C5aR1-mediated ERK1/2 phosphorylation or intracellular calcium mobilization in HMDMs. Functional analysis using transwell migration and µ-slide chemotaxis assays indicated that Rab5a regulates C5a-induced chemotaxis of HMDMs. Further, C5aR1 was found to mediate interaction of Rab5a with β-arrestin2 but not with G proteins in HMDMs. Furthermore, C5a-induced secretion of pro-inflammatory chemokines (CCL2, CCL3) from HMDMs was attenuated by Rab5a or β-arrestin2 knockdown or by pharmacological inhibition with a C5aR1 antagonist or a PI3K inhibitor. These findings reveal a C5a-C5aR1-β-arrestin2-Rab5a-PI3K signaling pathway that regulates chemotaxis and pro-inflammatory chemokine secretion in HMDMs and suggests new ways of selectively modulating C5a-induced inflammatory outputs.
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Affiliation(s)
- Kai-Chen Wu
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Nicholas D. Condon
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Timothy A. Hill
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Robert C. Reid
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - David P. Fairlie
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Junxian Lim
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
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7
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Xu X, Wu G. Non-canonical Golgi-compartmentalized Gβγ signaling: mechanisms, functions, and therapeutic targets. Trends Pharmacol Sci 2023; 44:98-111. [PMID: 36494204 PMCID: PMC9901158 DOI: 10.1016/j.tips.2022.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 12/13/2022]
Abstract
G protein Gβγ subunits are key mediators of G protein-coupled receptor (GPCR) signaling under physiological and pathological conditions; their inhibitors have been tested for the treatment of human disease. Conventional wisdom is that the Gβγ complex is activated and subsequently exerts its functions at the plasma membrane (PM). Recent studies have revealed non-canonical activation of Gβγ at intracellular organelles, where the Golgi apparatus is a major locale, via translocation or local activation. Golgi-localized Gβγ activates specific signaling cascades and regulates fundamental cell processes such as membrane trafficking, proliferation, and migration. More recent studies have shown that inhibiting Golgi-compartmentalized Gβγ signaling attenuates cardiomyocyte hypertrophy and prostate tumorigenesis, indicating new therapeutic targets. We review novel activation mechanisms and non-canonical functions of Gβγ at the Golgi, and discuss potential therapeutic interventions by targeting Golgi-biased Gβγ-directed signaling.
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Affiliation(s)
- Xin Xu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA.
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8
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Kumar GA, Puthenveedu MA. Diversity and specificity in location-based signaling outputs of neuronal GPCRs. Curr Opin Neurobiol 2022; 76:102601. [DOI: 10.1016/j.conb.2022.102601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/27/2022] [Accepted: 06/01/2022] [Indexed: 11/30/2022]
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9
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Martínez-Morales JC, Solís KH, Romero-Ávila MT, Reyes-Cruz G, García-Sáinz JA. Cell Trafficking and Function of G Protein-coupled Receptors. Arch Med Res 2022; 53:451-460. [PMID: 35835604 DOI: 10.1016/j.arcmed.2022.06.008] [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: 05/13/2022] [Revised: 06/22/2022] [Accepted: 06/30/2022] [Indexed: 11/30/2022]
Abstract
The G protein-coupled receptors (GPCRs) are plasma membrane proteins that function as sensors of changes in the internal and external milieux and play essential roles in health and disease. They are targets of hormones, neurotransmitters, local hormones (autacoids), and a large proportion of the drugs currently used as therapeutics and for "recreational" purposes. Understanding how these receptors signal and are regulated is fundamental for progress in areas such as physiology and pharmacology. This review will focus on what is currently known about their structure, the molecular events that trigger their signaling, and their trafficking to endosomal compartments. GPCR phosphorylation and its role in desensitization (signaling switching) are also discussed. It should be mentioned that the volume of information available is enormous given the large number and variety of GPCRs. However, knowledge is fragmentary even for the most studied receptors, such as the adrenergic receptors. Therefore, we attempt to present a panoramic view of the field, conscious of the risks and limitations (such as oversimplifications and incorrect generalizations). We hope this will provoke further research in the area. It is currently accepted that GPCR internalization plays a role signaling events. Therefore, the processes that allow them to internalize and recycle back to the plasma membrane are briefly reviewed. The functions of cytoskeletal elements (mainly actin filaments and microtubules), the molecular motors implicated in receptor trafficking (myosin, kinesin, and dynein), and the GTPases involved in GPCR internalization (dynamin) and endosomal sorting (Rab proteins), are discussed. The critical role phosphoinositide metabolism plays in regulating these events is also depicted.
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Affiliation(s)
- Juan Carlos Martínez-Morales
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - K Helivier Solís
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - M Teresa Romero-Ávila
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Guadalupe Reyes-Cruz
- Departamento de Biología Celular, Centro de Investigación y Estudios Avanzados-Instituto Politécnico Nacional, Ciudad de México, México
| | - J Adolfo García-Sáinz
- Departamento de Biología Celular y Desarrollo, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, México.
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10
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Xu X, Wu G. Human C1orf27 protein interacts with α 2A-adrenergic receptor and regulates its anterograde transport. J Biol Chem 2022; 298:102021. [PMID: 35551911 PMCID: PMC9168726 DOI: 10.1016/j.jbc.2022.102021] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 05/02/2022] [Accepted: 05/04/2022] [Indexed: 11/25/2022] Open
Abstract
The molecular mechanisms underlying the anterograde surface transport of G protein–coupled receptors (GPCRs) after their synthesis in the endoplasmic reticulum (ER) are not well defined. In C. elegans, odorant response abnormal 4 has been implicated in the delivery of olfactory GPCRs to the cilia of chemosensory neurons. However, the function and regulation of its human homolog, C1orf27, in GPCR transport or in general membrane trafficking remain unknown. Here, we demonstrate that siRNA-mediated knockdown of C1orf27 markedly impedes the ER-to-Golgi export kinetics of newly synthesized α2A-adrenergic receptor (α2A-AR), a prototypic GPCR, with the half-time being prolonged by more than 65%, in mammalian cells in retention using the selective hooks assays. Using modified bioluminescence resonance energy transfer assays and ELISAs, we also show that C1orf27 knockdown significantly inhibits the surface transport of α2A-AR. Similarly, C1orf27 knockout by CRISPR-Cas9 markedly suppresses the ER–Golgi-surface transport of α2A-AR. In addition, we demonstrate that C1orf27 depletion attenuates the export of β2-AR and dopamine D2 receptor but not of epidermal growth factor receptor. We further show that C1orf27 physically associates with α2A-AR, specifically via its third intracellular loop and C terminus. Taken together, these data demonstrate an important role of C1orf27 in the trafficking of nascent GPCRs from the ER to the cell surface through the Golgi and provide novel insights into the regulation of the biosynthesis and anterograde transport of the GPCR family members.
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Affiliation(s)
- Xin Xu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA.
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11
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Xu X, Wei Z, Wu G. Specific motifs mediate post-synaptic and surface transport of G protein-coupled receptors. iScience 2022; 25:103643. [PMID: 35024582 PMCID: PMC8728401 DOI: 10.1016/j.isci.2021.103643] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 11/19/2021] [Accepted: 12/14/2021] [Indexed: 12/23/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are key regulators of synaptic functions. However, their targeted trafficking to synapses after synthesis is poorly understood. Here, we demonstrate that multiple motifs mediate α2B-adrenergic receptor transport to the dendritic and post-synaptic compartments in primary hippocampal neurons, with a single leucine residue on the first intracellular loop being specifically involved in synaptic targeting. The N-terminally located tyrosine-serine motif operates differently in neuronal and non-neuronal cells. We further show that the highly conserved dileucine (LL) motif in the C-terminus is required for the dendritic and post-synaptic traffic of all GPCRs studied. The LL motif also directs the export from the endoplasmic reticulum of a chimeric GPCR and confers its transport ability to vesicular stomatitis virus glycoprotein in cell lines. Collectively, these data reveal the intrinsic structural determinants for the synaptic targeting of nascent GPCRs and their cell-type-specific trafficking along the biosynthetic pathways.
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Affiliation(s)
- Xin Xu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Zhe Wei
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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12
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Ulloa-Aguirre A, Zariñán T, Gutiérrez-Sagal R, Tao YX. Targeting trafficking as a therapeutic avenue for misfolded GPCRs leading to endocrine diseases. Front Endocrinol (Lausanne) 2022; 13:934685. [PMID: 36093106 PMCID: PMC9452723 DOI: 10.3389/fendo.2022.934685] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 07/13/2022] [Indexed: 02/05/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are plasma membrane proteins associated with an array of functions. Mutations in these receptors lead to a number of genetic diseases, including diseases involving the endocrine system. A particular subset of loss-of-function mutant GPCRs are misfolded receptors unable to traffic to their site of function (i.e. the cell surface plasma membrane). Endocrine disorders in humans caused by GPCR misfolding include, among others, hypo- and hyper-gonadotropic hypogonadism, morbid obesity, familial hypocalciuric hypercalcemia and neonatal severe hyperparathyroidism, X-linked nephrogenic diabetes insipidus, congenital hypothyroidism, and familial glucocorticoid resistance. Several in vitro and in vivo experimental approaches have been employed to restore function of some misfolded GPCRs linked to endocrine disfunction. The most promising approach is by employing pharmacological chaperones or pharmacoperones, which assist abnormally and incompletely folded proteins to refold correctly and adopt a more stable configuration to pass the scrutiny of the cell's quality control system, thereby correcting misrouting. This review covers the most important aspects that regulate folding and traffic of newly synthesized proteins, as well as the experimental approaches targeted to overcome protein misfolding, with special focus on GPCRs involved in endocrine diseases.
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Affiliation(s)
- Alfredo Ulloa-Aguirre
- Red de Apoyo a la Investigación (RAI), National University of Mexico and Instituto Nacional de Ciencias Médicas y Nutrición SZ, Mexico City, Mexico
- *Correspondence: Alfredo Ulloa-Aguirre,
| | - Teresa Zariñán
- Red de Apoyo a la Investigación (RAI), National University of Mexico and Instituto Nacional de Ciencias Médicas y Nutrición SZ, Mexico City, Mexico
| | - Rubén Gutiérrez-Sagal
- Red de Apoyo a la Investigación (RAI), National University of Mexico and Instituto Nacional de Ciencias Médicas y Nutrición SZ, Mexico City, Mexico
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology & Pharmacology, Auburn University College of Veterinary Medicine, Auburn, AL, United States
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13
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Martínez-Morales JC, Romero-Ávila MT, Reyes-Cruz G, García-Sáinz JA. Roles of receptor phosphorylation and Rab proteins in G protein-coupled receptor function and trafficking. Mol Pharmacol 2021; 101:144-153. [PMID: 34969830 DOI: 10.1124/molpharm.121.000429] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 12/22/2021] [Indexed: 11/22/2022] Open
Abstract
The G Protein-Coupled Receptors form the most abundant family of membrane proteins and are crucial physiological players in the homeostatic equilibrium, which we define as health. They also participate in the pathogenesis of many diseases and are frequent targets of therapeutic intervention. Considering their importance, it is not surprising that different mechanisms regulate their function, including desensitization, resensitization, internalization, recycling to the plasma membrane, and degradation. These processes are modulated in a highly coordinated and specific way by protein kinases and phosphatases, ubiquitin ligases, protein adaptors, interaction with multifunctional complexes, molecular motors, phospholipid metabolism, and membrane distribution. This review describes significant advances in the study of the regulation of these receptors by phosphorylation and endosomal traffic (where signaling can take place); we revisited the bar code hypothesis and include two additional observations: a) that different phosphorylation patterns seem to be associated with internalization and endosome sorting for recycling or degradation, and b) that, surprisingly, phosphorylation of some G protein-coupled receptors appears to be required for proper receptor insertion into the plasma membrane. Significance Statement G protein-coupled receptor phosphorylation is an early event in desensitization/ signaling switching, endosomal traffic, and internalization. These events seem crucial for receptor responsiveness, cellular localization, and fate (recycling/ degradation) with important pharmacological/ therapeutic implications. Phosphorylation sites vary depending on the cells in which they are expressed and on the stimulus that leads to such covalent modification. Surprisingly, evidence suggests that phosphorylation also seems to be required for proper insertion into the plasma membrane for some receptors.
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14
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Degrandmaison J, Grisé O, Parent JL, Gendron L. Differential barcoding of opioid receptors trafficking. J Neurosci Res 2021; 100:99-128. [PMID: 34559903 DOI: 10.1002/jnr.24949] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 07/25/2021] [Accepted: 08/05/2021] [Indexed: 11/09/2022]
Abstract
Over the past several years, studies have highlighted the δ-opioid receptor (DOPr) as a promising therapeutic target for chronic pain management. While exhibiting milder undesired effects than most currently prescribed opioids, its specific agonists elicit effective analgesic responses in numerous animal models of chronic pain, including inflammatory, neuropathic, diabetic, and cancer-related pain. However, as compared with the extensively studied μ-opioid receptor, the molecular mechanisms governing its trafficking remain elusive. Recent advances have denoted several significant particularities in the regulation of DOPr intracellular routing, setting it apart from the other members of the opioid receptor family. Although they share high homology, each opioid receptor subtype displays specific amino acid patterns potentially involved in the regulation of its trafficking. These precise motifs or "barcodes" are selectively recognized by regulatory proteins and therefore dictate several aspects of the itinerary of a receptor, including its anterograde transport, internalization, recycling, and degradation. With a specific focus on the regulation of DOPr trafficking, this review will discuss previously reported, as well as potential novel trafficking barcodes within the opioid and nociceptin/orphanin FQ opioid peptide receptors, and their impact in determining distinct interactomes and physiological responses.
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Affiliation(s)
- Jade Degrandmaison
- Département de Pharmacologie-Physiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada.,Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada.,Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada.,Quebec Network of Junior Pain Investigators, QC, Canada
| | - Olivier Grisé
- Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada.,Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Jean-Luc Parent
- Département de Médecine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada.,Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Louis Gendron
- Département de Pharmacologie-Physiologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada.,Institut de Pharmacologie de Sherbrooke, Centre de Recherche du CHUS, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC, Canada.,Quebec Pain Research Network, QC, Canada
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15
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Kunselman JM, Lott J, Puthenveedu MA. Mechanisms of selective G protein-coupled receptor localization and trafficking. Curr Opin Cell Biol 2021; 71:158-165. [PMID: 33965654 PMCID: PMC8328924 DOI: 10.1016/j.ceb.2021.03.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 03/09/2021] [Indexed: 12/21/2022]
Abstract
The trafficking of G protein-coupled receptors (GPCRs) to different membrane compartments has recently emerged as being a critical determinant of the signaling profiles of activation. GPCRs, which share many structural and functional similarities, also share many mechanisms that traffic them between compartments. This sharing raises the question of how the trafficking of individual GPCRs is selectively regulated. Here, we will discuss recent studies addressing the mechanisms that contribute to selectivity in endocytic and biosynthetic trafficking of GPCRs.
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Affiliation(s)
- Jennifer M Kunselman
- Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Joshua Lott
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Manojkumar A Puthenveedu
- Program in Cellular and Molecular Biology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA.
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16
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Wei Z, Xu X, Fang Y, Khater M, Naughton SX, Hu G, Terry AV, Wu G. Rab43 GTPase directs postsynaptic trafficking and neuron-specific sorting of G protein-coupled receptors. J Biol Chem 2021; 296:100517. [PMID: 33676895 PMCID: PMC8050390 DOI: 10.1016/j.jbc.2021.100517] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/25/2021] [Accepted: 03/03/2021] [Indexed: 12/31/2022] Open
Abstract
G protein–coupled receptors (GPCRs) are important modulators of synaptic functions. A fundamental but poorly addressed question in neurobiology is how targeted GPCR trafficking is achieved. Rab GTPases are the master regulators of vesicle-mediated membrane trafficking, but their functions in the synaptic presentation of newly synthesized GPCRs are virtually unknown. Here, we investigate the role of Rab43, via dominant-negative inhibition and CRISPR–Cas9–mediated KO, in the export trafficking of α2-adrenergic receptor (α2-AR) and muscarinic acetylcholine receptor (mAChR) in primary neurons and cells. We demonstrate that Rab43 differentially regulates the overall surface expression of endogenous α2-AR and mAChR, as well as their signaling, in primary neurons. In parallel, Rab43 exerts distinct effects on the dendritic and postsynaptic transport of specific α2B-AR and M3 mAChR subtypes. More interestingly, the selective actions of Rab43 toward α2B-AR and M3 mAChR are neuronal cell specific and dictated by direct interaction. These data reveal novel, neuron-specific functions for Rab43 in the dendritic and postsynaptic targeting and sorting of GPCRs and imply multiple forward delivery routes for different GPCRs in neurons. Overall, this study provides important insights into regulatory mechanisms of GPCR anterograde traffic to the functional destination in neurons.
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Affiliation(s)
- Zhe Wei
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Xin Xu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Yinquan Fang
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA; Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Mostafa Khater
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Sean X Naughton
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Gang Hu
- Department of Pharmacology, Nanjing Medical University, Nanjing, China
| | - Alvin V Terry
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA.
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17
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Jones AJY, Gabriel F, Tandale A, Nietlispach D. Structure and Dynamics of GPCRs in Lipid Membranes: Physical Principles and Experimental Approaches. Molecules 2020; 25:E4729. [PMID: 33076366 PMCID: PMC7587580 DOI: 10.3390/molecules25204729] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/11/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023] Open
Abstract
Over the past decade, the vast amount of information generated through structural and biophysical studies of GPCRs has provided unprecedented mechanistic insight into the complex signalling behaviour of these receptors. With this recent information surge, it has also become increasingly apparent that in order to reproduce the various effects that lipids and membranes exert on the biological function for these allosteric receptors, in vitro studies of GPCRs need to be conducted under conditions that adequately approximate the native lipid bilayer environment. In the first part of this review, we assess some of the more general effects that a membrane environment exerts on lipid bilayer-embedded proteins such as GPCRs. This is then followed by the consideration of more specific effects, including stoichiometric interactions with specific lipid subtypes. In the final section, we survey a range of different membrane mimetics that are currently used for in vitro studies, with a focus on NMR applications.
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Affiliation(s)
| | | | | | - Daniel Nietlispach
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK; (A.J.Y.J.); (F.G.); (A.T.)
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18
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Blagotinšek Cokan K, Mavri M, Rutland CS, Glišić S, Senćanski M, Vrecl M, Kubale V. Critical Impact of Different Conserved Endoplasmic Retention Motifs and Dopamine Receptor Interacting Proteins (DRIPs) on Intracellular Localization and Trafficking of the D 2 Dopamine Receptor (D 2-R) Isoforms. Biomolecules 2020; 10:biom10101355. [PMID: 32977535 PMCID: PMC7598153 DOI: 10.3390/biom10101355] [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: 07/03/2020] [Revised: 09/09/2020] [Accepted: 09/18/2020] [Indexed: 01/13/2023] Open
Abstract
The type 2 dopamine receptor D2 (D2-R), member of the G protein-coupled receptor (GPCR) superfamily, exists in two isoforms, short (D2S-R) and long (D2L-R). They differ by an additional 29 amino acids (AA) in the third cytoplasmic loop (ICL3) of the D2L-R. These isoforms differ in their intracellular localization and trafficking functionality, as D2L-R possesses a larger intracellular pool, mostly in the endoplasmic reticulum (ER). This review focuses on the evolutionarily conserved motifs in the ICL3 of the D2-R and proteins interacting with the ICL3 of both isoforms, specifically with the 29 AA insert. These motifs might be involved in D2-R exit from the ER and have an impact on cell-surface and intracellular localization and, therefore, also play a role in the function of dopamine receptor signaling, ligand binding and possible homo/heterodimerization. Our recent bioinformatic data on potential new interaction partners for the ICL3 of D2-Rs are also presented. Both are highly relevant, and have clinical impacts on the pathophysiology of several diseases such as Parkinson’s disease, schizophrenia, Tourette’s syndrome, Huntington’s disease, manic depression, and others, as they are connected to a variety of essential motifs and differences in communication with interaction partners.
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Affiliation(s)
- Kaja Blagotinšek Cokan
- Department of Anatomy, Histology with Embryology and Cytology, Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia; (K.B.C.); (M.M.); (M.V.)
| | - Maša Mavri
- Department of Anatomy, Histology with Embryology and Cytology, Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia; (K.B.C.); (M.M.); (M.V.)
| | - Catrin Sian Rutland
- School of Veterinary Medicine and Science, Medical Faculty, University of Nottingham, Sutton, Bonington Campus, Loughborough LE12 5RD, UK;
| | - Sanja Glišić
- Center for Multidisciplinary Research, Institute of Nuclear Sciences VINCA, University of Belgrade, Mike Petrovića Alasa 12-14, 11351 Vinča, Belgrade, Serbia; (S.G.); (M.S.)
| | - Milan Senćanski
- Center for Multidisciplinary Research, Institute of Nuclear Sciences VINCA, University of Belgrade, Mike Petrovića Alasa 12-14, 11351 Vinča, Belgrade, Serbia; (S.G.); (M.S.)
| | - Milka Vrecl
- Department of Anatomy, Histology with Embryology and Cytology, Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia; (K.B.C.); (M.M.); (M.V.)
| | - Valentina Kubale
- Department of Anatomy, Histology with Embryology and Cytology, Institute of Preclinical Sciences, Veterinary Faculty, University of Ljubljana, Gerbičeva 60, 1000 Ljubljana, Slovenia; (K.B.C.); (M.M.); (M.V.)
- Correspondence:
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19
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Xu X, Wu G. Quantification of The Surface Expression of G Protein-coupled Receptors Using Intact Live-cell Radioligand Binding Assays. Bio Protoc 2020; 10:e3761. [PMID: 33628863 DOI: 10.21769/bioprotoc.3761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
G protein-coupled receptors (GPCRs) are the most structurally diverse family of signaling proteins and regulate a variety of cell function. For most GPCRs, the cell surface is their functional destination where they are able to respond a wide range of extracellular stimuli, leading to the activation of intracellular signal transduction cascades. Thus, the quantity of receptor expression at the cell surface is a crucial factor regulating the functionality of the receptors. Over the past decades, many methods have been developed to measure the cell surface expression of GPCRs. Here, we describe an intact live-cell radioligand binding assay to quantify the surface expression of GPCRs at the endogenous levels or after overexpression. In this assay, cell cultures will be incubated with specific cell-nonpermeable radioligands which selectively and stoichiometrically bind to individual GPCRs and the receptor numbers at the cell surface are quantified by the radioactivity of receptor-bound ligands. This method is highly specific for measuring the functional GPCRs at the surface of intact live cells and is particularly useful for endogenous, low-abundant GPCRs.
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Affiliation(s)
- Xin Xu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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20
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Lemos Duarte M, Devi LA. Post-translational Modifications of Opioid Receptors. Trends Neurosci 2020; 43:417-432. [PMID: 32459993 PMCID: PMC7323054 DOI: 10.1016/j.tins.2020.03.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 03/26/2020] [Accepted: 03/26/2020] [Indexed: 12/13/2022]
Abstract
Post-translational modifications (PTMs) are key events in signal transduction since they affect protein function by regulating their abundance and/or activity. PTMs involve the covalent attachment of functional groups to specific amino acids. Since they tend to be generally reversible, PTMs serve as regulators of signal transduction pathways. G-protein-coupled receptors (GPCRs) are major signaling proteins that undergo multiple types of PTMs. In this Review, we focus on the opioid receptors, members of GPCR family A, and highlight recent advances in the field that have underscored the importance of PTMs in the functional regulation of these receptors. Since opioid receptor activity plays a central role in the development of tolerance and addiction to morphine and other drugs of abuse, understanding the molecular mechanisms regulating receptor activity is of fundamental importance.
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Affiliation(s)
- Mariana Lemos Duarte
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Lakshmi A Devi
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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21
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Pal S, Chattopadhyay A. Extramembranous Regions in G Protein-Coupled Receptors: Cinderella in Receptor Biology? J Membr Biol 2019; 252:483-497. [DOI: 10.1007/s00232-019-00092-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 08/20/2019] [Indexed: 12/22/2022]
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22
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A Naturally Occurring Splice Variant of GGA1 Inhibits the Anterograde Post-Golgi Traffic of α 2B-Adrenergic Receptor. Sci Rep 2019; 9:10378. [PMID: 31316103 PMCID: PMC6637153 DOI: 10.1038/s41598-019-46547-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 06/29/2019] [Indexed: 11/08/2022] Open
Abstract
The regulatory mechanisms of cell surface targeting of nascent G protein-coupled receptors (GPCRs) en route from the endoplasmic reticulum through the Golgi remain poorly understood. We have recently demonstrated that three Golgi-localized, γ-adaptin ear domain homology, ADP ribosylation factor-binding proteins (GGAs) mediate the post-Golgi export of α2B-adrenergic receptor (α2B-AR), a prototypic GPCR, and directly interact with the receptor. In particular, GGA1 interaction with α2B-AR is mediated via its hinge domain. Here we determined the role of a naturally occurring truncated form of GGA1 (GGA1t) which lacks the N-terminal portion of the hinge domain in α2B-AR trafficking and elucidated the underlying mechanisms. We demonstrated that both GGA1 and GGA1t were colocalized and mainly expressed at the Golgi. In marked contrast to GGA1, the expression of GGA1t significantly attenuated the cell surface export of newly synthesized α2B-AR from the Golgi and in parallel receptor-mediated signaling. Furthermore, we found that GGA1t formed homodimers and heterodimers with GGA1. More interestingly, GGA1t was unable to bind the cargo α2B-AR and to recruit clathrin onto the trans-Golgi network. These data provide evidence implicating that the truncated form of GGA1 behaviors as a dominant-negative regulator for the cell surface export of α2B-AR and this function of GGA1t is attributed to its abilities to dimerize with its wide type counterpart and to inhibit cargo interaction and clathrin recruitment to form specialized transport vesicles.
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23
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Margaria JP, Ratto E, Gozzelino L, Li H, Hirsch E. Class II PI3Ks at the Intersection between Signal Transduction and Membrane Trafficking. Biomolecules 2019; 9:E104. [PMID: 30884740 PMCID: PMC6468456 DOI: 10.3390/biom9030104] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 03/01/2019] [Accepted: 03/11/2019] [Indexed: 12/11/2022] Open
Abstract
Phosphorylation of inositol phospholipids by the family of phosphoinositide 3-kinases (PI3Ks) is crucial in controlling membrane lipid composition and regulating a wide range of intracellular processes, which include signal transduction and vesicular trafficking. In spite of the extensive knowledge on class I PI3Ks, recent advances in the study of the three class II PI3Ks (PIK3C2A, PIK3C2B and PIK3C2G) reveal their distinct and non-overlapping cellular roles and localizations. By finely tuning membrane lipid composition in time and space among different cellular compartments, this class of enzymes controls many cellular processes, such as proliferation, survival and migration. This review focuses on the recent developments regarding the coordination of membrane trafficking and intracellular signaling of class II PI3Ks through the confined phosphorylation of inositol phospholipids.
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Affiliation(s)
- Jean Piero Margaria
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Turin, 10126 Turin, Italy.
| | - Edoardo Ratto
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Turin, 10126 Turin, Italy.
| | - Luca Gozzelino
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Turin, 10126 Turin, Italy.
| | - Huayi Li
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Turin, 10126 Turin, Italy.
| | - Emilio Hirsch
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Turin, 10126 Turin, Italy.
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