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Mustafa S, Bajic JE, Barry B, Evans S, Siemens KR, Hutchinson MR, Grace PM. One immune system plays many parts: The dynamic role of the immune system in chronic pain and opioid pharmacology. Neuropharmacology 2023; 228:109459. [PMID: 36775098 PMCID: PMC10015343 DOI: 10.1016/j.neuropharm.2023.109459] [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: 12/06/2022] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023]
Abstract
The transition from acute to chronic pain is an ongoing major problem for individuals, society and healthcare systems around the world. It is clear chronic pain is a complex multidimensional biological challenge plagued with difficulties in pain management, specifically opioid use. In recent years the role of the immune system in chronic pain and opioid pharmacology has come to the forefront. As a highly dynamic and versatile network of cells, tissues and organs, the immune system is perfectly positioned at the microscale level to alter nociception and drive structural adaptations that underpin chronic pain and opioid use. In this review, we highlight the need to understand the dynamic and adaptable characteristics of the immune system and their role in the transition, maintenance and resolution of chronic pain. The complex multidimensional interplay of the immune system with multiple physiological systems may provide new transformative insight for novel targets for clinical management and treatment of chronic pain. This article is part of the Special Issue on "Opioid-induced changes in addiction and pain circuits".
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Affiliation(s)
- Sanam Mustafa
- School of Biomedicine, The University of Adelaide, Adelaide, SA, Australia; Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, The University of Adelaide, Adelaide, SA, Australia; Davies Livestock Research Centre, The University of Adelaide, Roseworthy, SA, Australia.
| | - Juliana E Bajic
- School of Biomedicine, The University of Adelaide, Adelaide, SA, Australia; Davies Livestock Research Centre, The University of Adelaide, Roseworthy, SA, Australia
| | - Benjamin Barry
- School of Biomedicine, The University of Adelaide, Adelaide, SA, Australia
| | - Samuel Evans
- School of Biomedicine, The University of Adelaide, Adelaide, SA, Australia; Davies Livestock Research Centre, The University of Adelaide, Roseworthy, SA, Australia
| | - Kariel R Siemens
- School of Biomedicine, The University of Adelaide, Adelaide, SA, Australia
| | - Mark R Hutchinson
- School of Biomedicine, The University of Adelaide, Adelaide, SA, Australia; Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, The University of Adelaide, Adelaide, SA, Australia; Davies Livestock Research Centre, The University of Adelaide, Roseworthy, SA, Australia
| | - Peter M Grace
- Laboratories of Neuroimmunology, Department of Symptom Research, University of Texas MD Anderson Cancer Center, Houston, TX, USA; MD Anderson Pain Research Consortium, Houston, TX, USA
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2
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Bean BDM, Mulvihill CJ, Garge RK, Boutz DR, Rousseau O, Floyd BM, Cheney W, Gardner EC, Ellington AD, Marcotte EM, Gollihar JD, Whiteway M, Martin VJJ. Functional expression of opioid receptors and other human GPCRs in yeast engineered to produce human sterols. Nat Commun 2022; 13:2882. [PMID: 35610225 PMCID: PMC9130329 DOI: 10.1038/s41467-022-30570-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 05/09/2022] [Indexed: 12/12/2022] Open
Abstract
The yeast Saccharomyces cerevisiae is powerful for studying human G protein-coupled receptors as they can be coupled to its mating pathway. However, some receptors, including the mu opioid receptor, are non-functional, which may be due to the presence of the fungal sterol ergosterol instead of cholesterol. Here we engineer yeast to produce cholesterol and introduce diverse mu, delta, and kappa opioid receptors to create sensitive opioid biosensors that recapitulate agonist binding profiles and antagonist inhibition. Additionally, human mu opioid receptor variants, including those with clinical relevance, largely display expected phenotypes. By testing mu opioid receptor-based biosensors with systematically adjusted cholesterol biosynthetic intermediates, we relate sterol profiles to biosensor sensitivity. Finally, we apply sterol-modified backgrounds to other human receptors revealing sterol influence in SSTR5, 5-HTR4, FPR1, and NPY1R signaling. This work provides a platform for generating human G protein-coupled receptor-based biosensors, facilitating receptor deorphanization and high-throughput screening of receptors and effectors.
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Affiliation(s)
- Björn D M Bean
- Department of Biology, Centre for Applied Synthetic Biology, Concordia University, Montréal, QC, H4B1R6, Canada
| | - Colleen J Mulvihill
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Riddhiman K Garge
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Daniel R Boutz
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, 78712, USA
- DEVCOM Army Research Laboratory-South, Austin, 78712, TX, USA
| | - Olivier Rousseau
- Department of Biology, Centre for Applied Synthetic Biology, Concordia University, Montréal, QC, H4B1R6, Canada
| | - Brendan M Floyd
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, 78712, USA
| | - William Cheney
- Department of Biology, Centre for Applied Synthetic Biology, Concordia University, Montréal, QC, H4B1R6, Canada
| | - Elizabeth C Gardner
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Andrew D Ellington
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Edward M Marcotte
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Jimmy D Gollihar
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, 78712, USA.
- DEVCOM Army Research Laboratory-South, Austin, 78712, TX, USA.
- Center for Molecular and Translational Human Infectious Diseases Research, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute, Houston Methodist Hospital, Houston, TX, USA.
| | - Malcolm Whiteway
- Department of Biology, Centre for Applied Synthetic Biology, Concordia University, Montréal, QC, H4B1R6, Canada
| | - Vincent J J Martin
- Department of Biology, Centre for Applied Synthetic Biology, Concordia University, Montréal, QC, H4B1R6, Canada.
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3
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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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4
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Wang W, Tian Y, Shi X, Ma Q, Xu Y, Yang G, Yi W, Shi Y, Zhou N. N-glycosylation of the human neuropeptide QRFP receptor (QRFPR) is essential for ligand binding and receptor activation. J Neurochem 2021; 158:138-152. [PMID: 33655503 DOI: 10.1111/jnc.15337] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 02/23/2021] [Accepted: 02/24/2021] [Indexed: 11/29/2022]
Abstract
The newly identified pyroglutamylated RFamide peptide (QRFP) signaling system has been shown to be implicated in regulating a variety of physiological processes. G-protein-coupled receptors (GPCRs) are preferentially N-glycosylated on extracellular domains. The human QRFP receptor QRFPR (GPR103) possesses three N-glycosylation consensus sites, two located on the N-terminal domain (N5 and N19) and one on the first extracellular loop (ECL1) (N106); however, to date, their role in QRFPR expression and signaling has not been established. Here, we combined mutants with glutamine substitution of the critical asparagines of the consensus sites with glycosidase PNGase F and N-glycosylation inhibitor tunicamycin to study the effect of N-glycosylation in the regulation of QRFPR cell surface expression and signaling. Western blot analysis performed with site-directed mutagenesis revealed that two asparagines at N19 in the N-terminus and N106 in ECL1, but not N5 in the N-terminus, served as sites for N-glycosylation. Treatment with PNGase F and tunicamycin resulted in a reduction in both two-protein species, ~43 kDa and ~85 kDa in size, by 2-4 kDa. Analysis with confocal microscopy and quantitative ELISA showed that N-glycosylation of QRFPR is not essentially required for targeting the cell membrane. However, further binding assay and functional assays demonstrated that removal of N-glycosylation sequons or treatment with tunicamycin led to significant impairments in the interaction of receptor with QRFP26 and downstream signaling. Thus, our findings suggest that for the human QRFP receptor (QRFPR), N-glycosylation is not important for cell surface expression but is a pre-requisite for ligand binding and receptor activation.
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Affiliation(s)
- Weiwei Wang
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yanan Tian
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaoliu Shi
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Qiang Ma
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yue Xu
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Gangjie Yang
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Wen Yi
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ying Shi
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Naiming Zhou
- Institute of Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
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5
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Metabolomics reveals biomarkers of opioid use disorder. Transl Psychiatry 2021; 11:103. [PMID: 33542199 PMCID: PMC7862627 DOI: 10.1038/s41398-021-01228-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 01/08/2021] [Accepted: 01/18/2021] [Indexed: 01/30/2023] Open
Abstract
Opioid use disorder (OUD) is diagnosed using the qualitative criteria defined by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Diagnostic biomarkers for OUD do not currently exist. Our study focused on developing objective biological markers to differentiate chronic opiate users with OUD from chronic opiate users without OUD. Using biospecimens from the Golestan Cohort Study, we compared the metabolomics profiles of high opium users who were diagnosed as OUD positive with high opium users who were diagnosed as OUD negative. High opium use was defined as maximum weekly opium usage greater than or equal to the median usage (2.4 g per week), and OUD was defined as having 2 or more DSM-5 criteria in any 12-month period. Among the 218 high opium users in this study, 80 were diagnosed as OUD negative, while 138 were diagnosed as OUD positive. Seven hundred and twelve peaks differentiated high opium users diagnosed as OUD positive from high opium users diagnosed as OUD negative. Stepwise logistic regression modeling of subject characteristics data together with the 712 differentiating peaks revealed a signature that is 95% predictive of an OUD positive diagnosis, a significant (p < 0.0001) improvement over a 63% accurate prediction based on subject characteristic data for these samples. These results suggest that a metabolic profile can be used to predict an OUD positive diagnosis.
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Patwardhan A, Cheng N, Trejo J. Post-Translational Modifications of G Protein-Coupled Receptors Control Cellular Signaling Dynamics in Space and Time. Pharmacol Rev 2020; 73:120-151. [PMID: 33268549 DOI: 10.1124/pharmrev.120.000082] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are a large family comprising >800 signaling receptors that regulate numerous cellular and physiologic responses. GPCRs have been implicated in numerous diseases and represent the largest class of drug targets. Although advances in GPCR structure and pharmacology have improved drug discovery, the regulation of GPCR function by diverse post-translational modifications (PTMs) has received minimal attention. Over 200 PTMs are known to exist in mammalian cells, yet only a few have been reported for GPCRs. Early studies revealed phosphorylation as a major regulator of GPCR signaling, whereas later reports implicated a function for ubiquitination, glycosylation, and palmitoylation in GPCR biology. Although our knowledge of GPCR phosphorylation is extensive, our knowledge of the modifying enzymes, regulation, and function of other GPCR PTMs is limited. In this review we provide a comprehensive overview of GPCR post-translational modifications with a greater focus on new discoveries. We discuss the subcellular location and regulatory mechanisms that control post-translational modifications of GPCRs. The functional implications of newly discovered GPCR PTMs on receptor folding, biosynthesis, endocytic trafficking, dimerization, compartmentalized signaling, and biased signaling are also provided. Methods to detect and study GPCR PTMs as well as PTM crosstalk are further highlighted. Finally, we conclude with a discussion of the implications of GPCR PTMs in human disease and their importance for drug discovery. SIGNIFICANCE STATEMENT: Post-translational modification of G protein-coupled receptors (GPCRs) controls all aspects of receptor function; however, the detection and study of diverse types of GPCR modifications are limited. A thorough understanding of the role and mechanisms by which diverse post-translational modifications regulate GPCR signaling and trafficking is essential for understanding dysregulated mechanisms in disease and for improving and refining drug development for GPCRs.
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Affiliation(s)
- Anand Patwardhan
- Department of Pharmacology and the Biomedical Sciences Graduate Program, School of Medicine, University of California, San Diego, La Jolla, California
| | - Norton Cheng
- Department of Pharmacology and the Biomedical Sciences Graduate Program, School of Medicine, University of California, San Diego, La Jolla, California
| | - JoAnn Trejo
- Department of Pharmacology and the Biomedical Sciences Graduate Program, School of Medicine, University of California, San Diego, La Jolla, California
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7
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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: 31] [Impact Index Per Article: 7.8] [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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8
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Janezic EM, Lauer SML, Williams RG, Chungyoun M, Lee KS, Navaluna E, Lau HT, Ong SE, Hague C. N-glycosylation of α 1D-adrenergic receptor N-terminal domain is required for correct trafficking, function, and biogenesis. Sci Rep 2020; 10:7209. [PMID: 32350295 PMCID: PMC7190626 DOI: 10.1038/s41598-020-64102-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 04/09/2020] [Indexed: 01/21/2023] Open
Abstract
G protein-coupled receptor (GPCR) biogenesis, trafficking, and function are regulated by post-translational modifications, including N-glycosylation of asparagine residues. α1D-adrenergic receptors (α1D-ARs) - key regulators of central and autonomic nervous system function - contain two putative N-glycosylation sites within the large N-terminal domain at N65 and N82. However, determining the glycosylation state of this receptor has proven challenging. Towards understanding the role of these putative glycosylation sites, site-directed mutagenesis and lectin affinity purification identified N65 and N82 as bona fide acceptors for N-glycans. Surprisingly, we also report that simultaneously mutating N65 and N82 causes early termination of α1D-AR between transmembrane domain 2 and 3. Label-free dynamic mass redistribution and cell surface trafficking assays revealed that single and double glycosylation deficient mutants display limited function with impaired plasma membrane expression. Confocal microscopy imaging analysis and SNAP-tag sucrose density fractionation assays revealed the dual glycosylation mutant α1D-AR is widely distributed throughout the cytosol and nucleus. Based on these novel findings, we propose α1D-AR transmembrane domain 2 acts as an ER localization signal during active protein biogenesis, and that α1D-AR N-terminal glycosylation is required for complete translation of nascent, functional receptor.
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Affiliation(s)
- Eric M Janezic
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98185, USA
| | - Sophia My-Linh Lauer
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98185, USA
| | - Robert George Williams
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98185, USA
| | - Michael Chungyoun
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98185, USA
| | - Kyung-Soon Lee
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98185, USA
| | - Edelmar Navaluna
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98185, USA
| | - Ho-Tak Lau
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98185, USA
| | - Shao-En Ong
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98185, USA
| | - Chris Hague
- Department of Pharmacology, School of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA, 98185, USA.
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9
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Goth CK, Petäjä-Repo UE, Rosenkilde MM. G Protein-Coupled Receptors in the Sweet Spot: Glycosylation and other Post-translational Modifications. ACS Pharmacol Transl Sci 2020; 3:237-245. [PMID: 32296765 DOI: 10.1021/acsptsci.0c00016] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Indexed: 12/11/2022]
Abstract
Post-translational modifications (PTMs) are a fundamental phenomenon across all classes of life and several hundred different types have been identified. PTMs contribute widely to the biological functions of proteins and greatly increase their diversity. One important class of proteins regulated by PTMs, is the cell surface expressed G protein-coupled receptors (GPCRs). While most PTMs have been shown to exert distinct biological functions, we are only beginning to approach the complexity that the potential interplay between different PTMs may have on biological functions and their regulation. Importantly, PTMs and their potential interplay represent an appealing mechanism for cell and tissue specific regulation of GPCR function and may partially contribute to functional selectivity of some GPCRs. In this review we highlight examples of PTMs located in GPCR extracellular domains, with special focus on glycosylation and the potential interplay with other close-by PTMs such as tyrosine sulfation, proteolytic cleavage, and phosphorylation.
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Affiliation(s)
- Christoffer K Goth
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, DK 2200, Denmark
| | - Ulla E Petäjä-Repo
- Medical Research Center Oulu, Research Unit of Biomedicine, University of Oulu, Oulu, FI-90014, Finland
| | - Mette M Rosenkilde
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, DK 2200, Denmark
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Guillien M, le Maire A, Mouhand A, Bernadó P, Bourguet W, Banères JL, Sibille N. IDPs and their complexes in GPCR and nuclear receptor signaling. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 174:105-155. [DOI: 10.1016/bs.pmbts.2020.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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11
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CCR5: Established paradigms and new frontiers for a 'celebrity' chemokine receptor. Cytokine 2019; 109:81-93. [PMID: 29903576 DOI: 10.1016/j.cyto.2018.02.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 02/14/2018] [Accepted: 02/16/2018] [Indexed: 01/04/2023]
Abstract
Because of the level of attention it received due to its role as the principal HIV coreceptor, CCR5 has been described as a 'celebrity' chemokine receptor. Here we describe the development of CCR5 inhibitory strategies that have been developed for HIV therapy and which are now additionally being considered for use in HIV prevention and cure. The wealth of CCR5-related tools that have been developed during the intensive investigation of CCR5 as an HIV drug target can now be turned towards the study of CCR5 as a model chemokine receptor. We also summarize what is currently known about the cell biology and pharmacology of CCR5, providing an update on new areas of investigation that have emerged in recent research. Finally, we discuss the potential of CCR5 as a drug target for diseases other than HIV, discussing the evidence linking CCR5 and its natural chemokine ligands with inflammatory diseases, particularly neuroinflammation, and certain cancers. These pathologies may provide new uses for the strategies for CCR5 blockade originally developed to combat HIV/AIDS.
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12
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Han Y, Xiao K, Tian Z. Comparative Glycomics Study of Cell-Surface N-Glycomes of HepG2 versus LO2 Cell Lines. J Proteome Res 2019; 18:372-379. [PMID: 30343578 DOI: 10.1021/acs.jproteome.8b00655] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cell-surface N-glycans play important roles in both inter- and intracellular processes, including cell adhesion and development, cell recognition, as well as cancer development and metastasis; detailed structural characterization of these N-glycans is thus paramount. Here we report our comparative N-glycomics study of cell-surface N-glycans of the hepatocellular carcinoma (HCC) HepG2 cells vs the normal liver LO2 cells. With sequential trypsin digestion of proteins, C18 depletion of peptides without glycosylation, PNGase F digestion of N-glycopeptides, PGC enrichment of N-glycans, CH3I permethylation of the enriched N-glycans, cell-surface N-glycomes of the HepG2 and LO2 cells were analyzed using C18-RPLC-MS/MS (HCD). With spectrum-level FDR no bigger than 1%, 351 and 310 N-glycans were identified for HepG2 and LO2, respectively, with comprehensive structural information (not only monosaccharide composition, but also sequence and linkage) by N-glycan database search engine GlySeeker. The percentage of hybrid N-glycans with tetra-antennary structures was substantially increased in the HepG2 cells. This comprehensive discovery study of differentially expressed cell-surface N-glycans in HepG2 vs LO2 serves as a solid reference for future validation study of glycosylation markers in HCC.
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Affiliation(s)
- Yuyin Han
- School of Chemical Science & Engineering, Shanghai Key Laboratory of Chemical Assessment and Sustainability , Tongji University , Shanghai 200092 , China
| | - Kaijie Xiao
- School of Chemical Science & Engineering, Shanghai Key Laboratory of Chemical Assessment and Sustainability , Tongji University , Shanghai 200092 , China
| | - Zhixin Tian
- School of Chemical Science & Engineering, Shanghai Key Laboratory of Chemical Assessment and Sustainability , Tongji University , Shanghai 200092 , China
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13
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Gendron L, Nagi K, Zeghal M, Giguère PM, Pineyro G. Molecular aspects of delta opioid receptors. OPIOID HORMONES 2019; 111:49-90. [DOI: 10.1016/bs.vh.2019.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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14
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Bai X, Li K, Yao L, Kang XL, Cai SQ. A forward genetic screen identifies chaperone CNX-1 as a conserved biogenesis regulator of ERG K + channels. J Gen Physiol 2018; 150:1189-1201. [PMID: 29941431 PMCID: PMC6080891 DOI: 10.1085/jgp.201812025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/15/2018] [Indexed: 12/15/2022] Open
Abstract
The human ether-a-go-go-related gene (hERG) encodes a voltage-gated potassium channel that controls repolarization of cardiac action potentials. Accumulating evidence suggests that most disease-related hERG mutations reduce the function of the channel by disrupting protein biogenesis of the channel in the endoplasmic reticulum (ER). However, the molecular mechanism underlying the biogenesis of ERG K+ channels is largely unknown. By forward genetic screening, we identified an ER-located chaperone CNX-1, the worm homologue of mammalian chaperone Calnexin, as a critical regulator for the protein biogenesis of UNC-103, the ERG-type K+ channel in Caenorhabditis elegans Loss-of-function mutations of cnx-1 decreased the protein level and current density of the UNC-103 K+ channel and suppressed the behavioral defects caused by a gain-of-function mutation in unc-103 Moreover, CNX-1 facilitated tetrameric assembly of UNC-103 channel subunits in a liposome-assisted cell-free translation system. Further studies showed that CNX-1 act in parallel to DNJ-1, another ER-located chaperone known to regulate maturation of UNC-103 channels, on controlling the protein biogenesis of UNC-103. Importantly, Calnexin interacted with hERG proteins in the ER in HEK293T cells. Deletion of calnexin reduced the expression and current densities of endogenous hERG K+ channels in SH-SY5Y cells. Collectively, we reveal an evolutionarily conserved chaperone CNX-1/Calnexin controlling the biogenesis of ERG-type K+ channels.
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Affiliation(s)
- Xue Bai
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Kai Li
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Li Yao
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Xin-Lei Kang
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Shi-Qing Cai
- Institute of Neuroscience and State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
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15
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Lackman JJ, Goth CK, Halim A, Vakhrushev SY, Clausen H, Petäjä-Repo UE. Site-specific O-glycosylation of N-terminal serine residues by polypeptide GalNAc-transferase 2 modulates human δ-opioid receptor turnover at the plasma membrane. Cell Signal 2018; 42:184-193. [PMID: 29097258 DOI: 10.1016/j.cellsig.2017.10.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 10/26/2017] [Accepted: 10/27/2017] [Indexed: 12/21/2022]
Abstract
G protein-coupled receptors (GPCRs) are an important protein family of signalling receptors that govern a wide variety of physiological functions. The capacity to transmit extracellular signals and the extent of cellular response are largely determined by the amount of functional receptors at the cell surface that is subject to complex and fine-tuned regulation. Here, we demonstrate that the cell surface expression level of an inhibitory GPCR, the human δ-opioid receptor (hδOR) involved in pain and mood regulation, is modulated by site-specific N-acetylgalactosamine (GalNAc) -type O-glycosylation. Importantly, we identified one out of the 20 polypeptide GalNAc-transferase isoforms, GalNAc-T2, as the specific regulator of O-glycosylation of Ser6, Ser25 and Ser29 in the N-terminal ectodomain of the receptor. This was demonstrated by in vitro glycosylation assays using peptides corresponding to the hδOR N-terminus, Vicia villosa lectin affinity purification of receptors expressed in HEK293 SimpleCells capable of synthesizing only truncated O-glycans, GalNAc-T edited cell line model systems, and site-directed mutagenesis of the putative O-glycosylation sites. Interestingly, a single-nucleotide polymorphism, at residue 27 (F27C), was found to alter O-glycosylation of the receptor in efficiency as well as in glycosite usage. Furthermore, flow cytometry and cell surface biotinylation assays using O-glycan deficient CHO-ldlD cells revealed that the absence of O-glycans results in decreased receptor levels at the plasma membrane due to enhanced turnover. In addition, mutation of the identified O-glycosylation sites led to a decrease in the number of ligand-binding competent receptors and impaired agonist-mediated inhibition of cyclic AMP accumulation in HEK293 cells. Thus, site-specific O-glycosylation by a selected GalNAc-T isoform can increase the stability of a GPCR, in a process that modulates the constitutive turnover and steady-state levels of functional receptors at the cell surface.
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MESH Headings
- Acetylgalactosamine/chemistry
- Acetylgalactosamine/metabolism
- Amino Acid Sequence
- Animals
- CHO Cells
- Cell Line, Tumor
- Cell Membrane/chemistry
- Cell Membrane/metabolism
- Chromatography, Affinity/methods
- Cricetulus
- Cyclic AMP/metabolism
- Glycosylation
- HEK293 Cells
- Hep G2 Cells
- Humans
- Mutagenesis, Site-Directed
- N-Acetylgalactosaminyltransferases/genetics
- N-Acetylgalactosaminyltransferases/metabolism
- Neurons/cytology
- Neurons/metabolism
- Peptides/chemical synthesis
- Peptides/metabolism
- Plant Lectins/chemistry
- Polymorphism, Single Nucleotide
- Protein Processing, Post-Translational
- Protein Stability
- Receptors, Opioid, delta/chemistry
- Receptors, Opioid, delta/genetics
- Receptors, Opioid, delta/metabolism
- Recombinant Fusion Proteins/chemistry
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Sequence Alignment
- Serine/metabolism
- Polypeptide N-acetylgalactosaminyltransferase
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Affiliation(s)
- Jarkko J Lackman
- Medical Research Center Oulu, Research Unit of Biomedicine, University of Oulu, FI-90014 Oulu, Finland
| | - Christoffer K Goth
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Adnan Halim
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Sergey Y Vakhrushev
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Henrik Clausen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Ulla E Petäjä-Repo
- Medical Research Center Oulu, Research Unit of Biomedicine, University of Oulu, FI-90014 Oulu, Finland.
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16
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Xiao Y, Han J, Wang Q, Mao Y, Wei M, Jia W, Wei L. A Novel Interacting Protein SERP1 Regulates the N‐Linked Glycosylation and Function of GLP‐1 Receptor in the Liver. J Cell Biochem 2017; 118:3616-3626. [DOI: 10.1002/jcb.26207] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 06/08/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Yuanyuan Xiao
- Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes MellitusShanghai Key Clinical Center for Metabolic DiseaseShanghai 200233China
| | - Junfeng Han
- Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes MellitusShanghai Key Clinical Center for Metabolic DiseaseShanghai 200233China
| | - Qianqian Wang
- Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes MellitusShanghai Key Clinical Center for Metabolic DiseaseShanghai 200233China
| | - Yueqin Mao
- Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes MellitusShanghai Key Clinical Center for Metabolic DiseaseShanghai 200233China
| | - Meilin Wei
- Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes MellitusShanghai Key Clinical Center for Metabolic DiseaseShanghai 200233China
| | - Weiping Jia
- Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes MellitusShanghai Key Clinical Center for Metabolic DiseaseShanghai 200233China
| | - Li Wei
- Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Clinical Center for Diabetes, Shanghai Diabetes Institute, Shanghai Key Laboratory of Diabetes MellitusShanghai Key Clinical Center for Metabolic DiseaseShanghai 200233China
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17
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Gendron L, Cahill CM, von Zastrow M, Schiller PW, Pineyro G. Molecular Pharmacology of δ-Opioid Receptors. Pharmacol Rev 2017; 68:631-700. [PMID: 27343248 DOI: 10.1124/pr.114.008979] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Opioids are among the most effective analgesics available and are the first choice in the treatment of acute severe pain. However, partial efficacy, a tendency to produce tolerance, and a host of ill-tolerated side effects make clinically available opioids less effective in the management of chronic pain syndromes. Given that most therapeutic opioids produce their actions via µ-opioid receptors (MOPrs), other targets are constantly being explored, among which δ-opioid receptors (DOPrs) are being increasingly considered as promising alternatives. This review addresses DOPrs from the perspective of cellular and molecular determinants of their pharmacological diversity. Thus, DOPr ligands are examined in terms of structural and functional variety, DOPrs' capacity to engage a multiplicity of canonical and noncanonical G protein-dependent responses is surveyed, and evidence supporting ligand-specific signaling and regulation is analyzed. Pharmacological DOPr subtypes are examined in light of the ability of DOPr to organize into multimeric arrays and to adopt multiple active conformations as well as differences in ligand kinetics. Current knowledge on DOPr targeting to the membrane is examined as a means of understanding how these receptors are especially active in chronic pain management. Insight into cellular and molecular mechanisms of pharmacological diversity should guide the rational design of more effective, longer-lasting, and better-tolerated opioid analgesics for chronic pain management.
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Affiliation(s)
- Louis Gendron
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
| | - Catherine M Cahill
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
| | - Mark von Zastrow
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
| | - Peter W Schiller
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
| | - Graciela Pineyro
- Département de Pharmacologie-Physiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Centre de Recherche du CHU de Sherbrooke, Centre d'excellence en neurosciences de l'Univeristé de Sherbrooke, and Institut de Pharmacologie de Sherbrooke, Sherbrooke, Quebec, Canada (L.G.); Québec Pain Research Network, Sherbrooke, Quebec, Canada (L.G.); Departments of Anesthesiology and Perioperative Care and Pharmacology, University of California, Irvine, California (C.M.C.); Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada (C.M.C.); Departments of Psychiatry and Cellular and Molecular Pharmacology, University of California, San Francisco, California (M.v.Z.); Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montréal, Montreal, Quebec, Canada (P.W.S.); and Departments of Psychiatry, Pharmacology, and Neurosciences, Faculty of Medicine, University of Montréal and Sainte-Justine Hospital Research Center, Montreal, Quebec, Canada (G.P.)
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18
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Goth CK, Tuhkanen HE, Khan H, Lackman JJ, Wang S, Narimatsu Y, Hansen LH, Overall CM, Clausen H, Schjoldager KT, Petäjä-Repo UE. Site-specific O-Glycosylation by Polypeptide N-Acetylgalactosaminyltransferase 2 (GalNAc-transferase T2) Co-regulates β 1-Adrenergic Receptor N-terminal Cleavage. J Biol Chem 2017; 292:4714-4726. [PMID: 28167537 PMCID: PMC5377785 DOI: 10.1074/jbc.m116.730614] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 01/29/2017] [Indexed: 01/08/2023] Open
Abstract
The β1-adrenergic receptor (β1AR) is a G protein-coupled receptor (GPCR) and the predominant adrenergic receptor subtype in the heart, where it mediates cardiac contractility and the force of contraction. Although it is the most important target for β-adrenergic antagonists, such as β-blockers, relatively little is yet known about its regulation. We have shown previously that β1AR undergoes constitutive and regulated N-terminal cleavage participating in receptor down-regulation and, moreover, that the receptor is modified by O-glycosylation. Here we demonstrate that the polypeptide GalNAc-transferase 2 (GalNAc-T2) specifically O-glycosylates β1AR at five residues in the extracellular N terminus, including the Ser-49 residue at the location of the common S49G single-nucleotide polymorphism. Using in vitro O-glycosylation and proteolytic cleavage assays, a cell line deficient in O-glycosylation, GalNAc-T-edited cell line model systems, and a GalNAc-T2 knock-out rat model, we show that GalNAc-T2 co-regulates the metalloproteinase-mediated limited proteolysis of β1AR. Furthermore, we demonstrate that impaired O-glycosylation and enhanced proteolysis lead to attenuated receptor signaling, because the maximal response elicited by the βAR agonist isoproterenol and its potency in a cAMP accumulation assay were decreased in HEK293 cells lacking GalNAc-T2. Our findings reveal, for the first time, a GPCR as a target for co-regulatory functions of site-specific O-glycosylation mediated by a unique GalNAc-T isoform. The results provide a new level of β1AR regulation that may open up possibilities for new therapeutic strategies for cardiovascular diseases.
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Affiliation(s)
- Christoffer K Goth
- From the Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Hanna E Tuhkanen
- the Medical Research Center Oulu, Research Unit of Biomedicine, University of Oulu, P.O. Box 5000, FI-90014 Oulu, Finland
| | - Hamayun Khan
- the Medical Research Center Oulu, Research Unit of Biomedicine, University of Oulu, P.O. Box 5000, FI-90014 Oulu, Finland
| | - Jarkko J Lackman
- the Medical Research Center Oulu, Research Unit of Biomedicine, University of Oulu, P.O. Box 5000, FI-90014 Oulu, Finland
| | - Shengjun Wang
- From the Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Yoshiki Narimatsu
- From the Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Lasse H Hansen
- the Department of Clinical Biochemistry, Rigshospitalet, Copenhagen University Hospital, DK-2100 Copenhagen Ø, Denmark and
| | - Christopher M Overall
- the Centre for Blood Research, Department of Oral Biological and Medical Sciences, and Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Henrik Clausen
- From the Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark
| | - Katrine T Schjoldager
- From the Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark,
| | - Ulla E Petäjä-Repo
- the Medical Research Center Oulu, Research Unit of Biomedicine, University of Oulu, P.O. Box 5000, FI-90014 Oulu, Finland,
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19
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St-Louis É, Degrandmaison J, Grastilleur S, Génier S, Blais V, Lavoie C, Parent JL, Gendron L. Involvement of the coatomer protein complex I in the intracellular traffic of the delta opioid receptor. Mol Cell Neurosci 2016; 79:53-63. [PMID: 28041939 DOI: 10.1016/j.mcn.2016.12.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 12/01/2016] [Accepted: 12/26/2016] [Indexed: 11/16/2022] Open
Abstract
The delta opioid receptor (DOPr) is known to be mainly expressed in intracellular compartments. It remains unknown why DOPr is barely exported to the cell surface, but it seems that a substantial proportion of the immature receptor is trapped within the endoplasmic reticulum (ER) and the Golgi network. In the present study, we performed LC-MS/MS analysis to identify putative protein partners involved in the retention of DOPr. Analysis of the proteins co-immunoprecipitating with Flag-DOPr in transfected HEK293 cells revealed the presence of numerous subunits of the coatomer protein complex I (COPI), a vesicle-coating complex involved in recycling resident proteins from the Golgi back to the ER. Further analysis of the amino acid sequence of DOPr identified multiple consensus di-lysine and di-arginine motifs within the intracellular segments of DOPr. Using cell-surface ELISA and GST pulldown assays, we showed that DOPr interacts with COPI through its intracellular loops 2 and 3 (ICL2 and ICL3, respectively) and that the mutation of the K164AK166 (ICL2) or K250EK252 (ICL3) putative COPI binding sites increased the cell-surface expression of DOPr in transfected cells. Altogether, our results indicate that COPI is a binding partner of DOPr and provide a putative mechanism to explain why DOPr is highly retained inside the cells.
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Affiliation(s)
- Étienne St-Louis
- Département de pharmacologie-physiologie, Université de Sherbrooke, Sherbrooke, Québec, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada; Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du CHUS, Sherbrooke, Québec, Canada
| | - Jade Degrandmaison
- Département de médecine, Université de Sherbrooke, Sherbrooke, Québec, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada; Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du CHUS, Sherbrooke, Québec, Canada
| | - Sébastien Grastilleur
- Département de pharmacologie-physiologie, Université de Sherbrooke, Sherbrooke, Québec, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada; Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du CHUS, Sherbrooke, Québec, Canada
| | - Samuel Génier
- Département de médecine, Université de Sherbrooke, Sherbrooke, Québec, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada; Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du CHUS, Sherbrooke, Québec, Canada
| | - Véronique Blais
- Département de pharmacologie-physiologie, Université de Sherbrooke, Sherbrooke, Québec, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada; Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du CHUS, Sherbrooke, Québec, Canada
| | - Christine Lavoie
- Département de pharmacologie-physiologie, Université de Sherbrooke, Sherbrooke, Québec, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada; Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du CHUS, Sherbrooke, Québec, Canada
| | - Jean-Luc Parent
- Département de médecine, Université de Sherbrooke, Sherbrooke, Québec, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada; Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du CHUS, Sherbrooke, Québec, Canada.
| | - Louis Gendron
- Département de pharmacologie-physiologie, Université de Sherbrooke, Sherbrooke, Québec, Canada; Département d'anesthésiologie, Université de Sherbrooke, Sherbrooke, Québec, Canada; Institut de pharmacologie de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada; Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada; Centre de recherche du CHUS, Sherbrooke, Québec, Canada; Quebec Pain Research Network, Québec, Canada.
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20
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Tétreault MP, Bourdin B, Briot J, Segura E, Lesage S, Fiset C, Parent L. Identification of Glycosylation Sites Essential for Surface Expression of the CaVα2δ1 Subunit and Modulation of the Cardiac CaV1.2 Channel Activity. J Biol Chem 2016; 291:4826-43. [PMID: 26742847 DOI: 10.1074/jbc.m115.692178] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Indexed: 12/15/2022] Open
Abstract
Alteration in the L-type current density is one aspect of the electrical remodeling observed in patients suffering from cardiac arrhythmias. Changes in channel function could result from variations in the protein biogenesis, stability, post-translational modification, and/or trafficking in any of the regulatory subunits forming cardiac L-type Ca(2+) channel complexes. CaVα2δ1 is potentially the most heavily N-glycosylated subunit in the cardiac L-type CaV1.2 channel complex. Here, we show that enzymatic removal of N-glycans produced a 50-kDa shift in the mobility of cardiac and recombinant CaVα2δ1 proteins. This change was also observed upon simultaneous mutation of the 16 Asn sites. Nonetheless, the mutation of only 6/16 sites was sufficient to significantly 1) reduce the steady-state cell surface fluorescence of CaVα2δ1 as characterized by two-color flow cytometry assays and confocal imaging; 2) decrease protein stability estimated from cycloheximide chase assays; and 3) prevent the CaVα2δ1-mediated increase in the peak current density and voltage-dependent gating of CaV1.2. Reversing the N348Q and N812Q mutations in the non-operational sextuplet Asn mutant protein partially restored CaVα2δ1 function. Single mutation N663Q and double mutations N348Q/N468Q, N348Q/N812Q, and N468Q/N812Q decreased protein stability/synthesis and nearly abolished steady-state cell surface density of CaVα2δ1 as well as the CaVα2δ1-induced up-regulation of L-type currents. These results demonstrate that Asn-663 and to a lesser extent Asn-348, Asn-468, and Asn-812 contribute to protein stability/synthesis of CaVα2δ1, and furthermore that N-glycosylation of CaVα2δ1 is essential to produce functional L-type Ca(2+) channels.
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Affiliation(s)
| | - Benoîte Bourdin
- From the Départment de Physiologie Moléculaire et Intégrative, Faculté de Médecine, and
| | - Julie Briot
- From the Départment de Physiologie Moléculaire et Intégrative, Faculté de Médecine, and
| | - Emilie Segura
- From the Départment de Physiologie Moléculaire et Intégrative, Faculté de Médecine, and
| | - Sylvie Lesage
- Départment de Microbiologie, Infectiologie, and Immunologie, Faculté de Médecine, Centre de Recherche de l'Hôpital Maisonneuve-Rosemont, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Céline Fiset
- Faculté de Pharmacie, Institut de Cardiologie de Montréal and
| | - Lucie Parent
- From the Départment de Physiologie Moléculaire et Intégrative, Faculté de Médecine, and
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21
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Sano M, Hashiba K, Higashi M, Okuda K. Alteration of glycan structures by swainsonine affects steroidogenesis in bovine luteal cells. Theriogenology 2015; 84:827-32. [DOI: 10.1016/j.theriogenology.2015.05.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 05/12/2015] [Indexed: 11/28/2022]
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Role of post-translational modifications on structure, function and pharmacology of class C G protein-coupled receptors. Eur J Pharmacol 2015; 763:233-40. [PMID: 25981296 DOI: 10.1016/j.ejphar.2015.05.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 03/06/2015] [Accepted: 05/11/2015] [Indexed: 11/22/2022]
Abstract
G protein-coupled receptors are divided into three classes (A, B and C) based on homology of their seven transmembrane domains. Class C is the smallest class with 22 human receptor subtypes including eight metabotropic glutamate (mGlu1-8) receptors, two GABAB receptors (GABAB1 and GABAB2), three taste receptors (T1R1-3), one calcium-sensing (CaS) receptor, one GPCR, class C, group 6, subtype A (GPRC6) receptor, and seven orphan receptors. G protein-coupled receptors undergo a number of post-translational modifications, which regulate their structure, function and/or pharmacology. Here, we review the existence of post-translational modifications in class C G protein-coupled receptors and their regulatory roles, with particular focus on glycosylation, phosphorylation, ubiquitination, SUMOylation, disulphide bonding and lipidation.
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Abstract
The plasma membrane (PM) and endocytic protein quality control (QC) in conjunction with the endosomal sorting machinery either repairs or targets conformationally damaged membrane proteins for lysosomal/vacuolar degradation. Here, we provide an overview of emerging aspects of the underlying mechanisms of PM QC that fulfill a critical role in preserving cellular protein homeostasis in health and diseases.
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Affiliation(s)
- Pirjo M Apaja
- Department of Physiology and Research Group Focused on Protein Structure (GRASP), McGill University, Montreal, Quebec, Canada; and
| | - Gergely L Lukacs
- Department of Physiology and Research Group Focused on Protein Structure (GRASP), McGill University, Montreal, Quebec, Canada; and Department of Biochemistry, McGill University, Montreal, Quebec, Canada
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Yasuda D, Imura Y, Ishii S, Shimizu T, Nakamura M. The atypical N-glycosylation motif, Asn-Cys-Cys, in human GPR109A is required for normal cell surface expression and intracellular signaling. FASEB J 2015; 29:2412-22. [PMID: 25690651 DOI: 10.1096/fj.14-267096] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/27/2015] [Indexed: 01/31/2023]
Abstract
Asparagine-linked glycosylation (N-glycosylation) is necessary for the proper folding of secreted and membrane proteins, including GPCRs. Thus, many GPCRs possess the N-glycosylation motif Asn-X-Ser/Thr at their N-termini and/or extracellular loops. We found that human GPR109A (hGPR109A) has an N-glycosylation site at Asn(17) in the N-terminal atypical motif, Asn(17)-Cys(18)-Cys(19). Why does hGPR109A require the atypical motif, rather than the typical sequence? Here we show that Asn(17)-Cys(18)-Cys(19) sequence of hGPR109A possesses 2 biologic roles. First, Asn(17)-X-Cys(19) contributed to hGPR109A N-glycosylation by acting as an atypical motif. This modification is required for the normal surface expression of hGPR109A, as evidenced by the reduced surface expression of the nonglycosylated mutants, hGPR109A/N17A, and the finding that hGPR109A/C19S and hGPR109A/C19T, which are N-glycosylated at Asn(17), exhibited expression similar to the wild-type receptor. Second, the X-Cys(18)-Cys(19) dicysteine is indispensable for hGPR109A function. Substitution of Cys(18) or Cys(19) residue to Ala impaired Gi-mediated signaling via hGPR109A. We propose the disulfide bond formations of these residues with other Cys existed in the extracellular loops for the proper folding. Together, these results suggest that the atypical motif Asn(17)-Cys(18)-Cys(19) is crucial for the normal surface trafficking and function of hGPR109A.
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Affiliation(s)
- Daisuke Yasuda
- *Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Immunology, Faculty of Medicine, Akita University, Akita, Japan; Department of Lipid Signaling, National Center for Global Health and Medicine, Tokyo, Japan; and Department of Life Science, Faculty of Science, Okayama University of Science, Okayama, Japan
| | - Yuki Imura
- *Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Immunology, Faculty of Medicine, Akita University, Akita, Japan; Department of Lipid Signaling, National Center for Global Health and Medicine, Tokyo, Japan; and Department of Life Science, Faculty of Science, Okayama University of Science, Okayama, Japan
| | - Satoshi Ishii
- *Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Immunology, Faculty of Medicine, Akita University, Akita, Japan; Department of Lipid Signaling, National Center for Global Health and Medicine, Tokyo, Japan; and Department of Life Science, Faculty of Science, Okayama University of Science, Okayama, Japan
| | - Takao Shimizu
- *Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Immunology, Faculty of Medicine, Akita University, Akita, Japan; Department of Lipid Signaling, National Center for Global Health and Medicine, Tokyo, Japan; and Department of Life Science, Faculty of Science, Okayama University of Science, Okayama, Japan
| | - Motonao Nakamura
- *Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan; Department of Immunology, Faculty of Medicine, Akita University, Akita, Japan; Department of Lipid Signaling, National Center for Global Health and Medicine, Tokyo, Japan; and Department of Life Science, Faculty of Science, Okayama University of Science, Okayama, Japan
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25
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Nørskov-Lauritsen L, Jørgensen S, Bräuner-Osborne H. N-glycosylation and disulfide bonding affects GPRC6A receptor expression, function, and dimerization. FEBS Lett 2015; 589:588-97. [PMID: 25617829 DOI: 10.1016/j.febslet.2015.01.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 12/28/2014] [Accepted: 01/14/2015] [Indexed: 12/20/2022]
Abstract
Investigation of post-translational modifications of receptor proteins is important for our understanding of receptor pharmacology and disease physiology. However, our knowledge about post-translational modifications of class C G protein-coupled receptors and how these modifications regulate expression and function is very limited. Herein, we show that the nutrient-sensing class C G protein-coupled receptor GPRC6A carries seven N-glycans and that one of these sites modulates surface expression whereas mutation of another site affects receptor function. GPRC6A has been speculated to form covalently linked dimers through cysteine disulfide linkage in the extracellular amino-terminal domain and here we show that GPRC6A indeed is a homodimer and that a disulfide bridge between the C131 residues is formed.
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Affiliation(s)
- Lenea Nørskov-Lauritsen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Stine Jørgensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Hans Bräuner-Osborne
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
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26
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Tao YX, Conn PM. Chaperoning G protein-coupled receptors: from cell biology to therapeutics. Endocr Rev 2014; 35:602-47. [PMID: 24661201 PMCID: PMC4105357 DOI: 10.1210/er.2013-1121] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 03/14/2014] [Indexed: 12/13/2022]
Abstract
G protein-coupled receptors (GPCRs) are membrane proteins that traverse the plasma membrane seven times (hence, are also called 7TM receptors). The polytopic structure of GPCRs makes the folding of GPCRs difficult and complex. Indeed, many wild-type GPCRs are not folded optimally, and defects in folding are the most common cause of genetic diseases due to GPCR mutations. Both general and receptor-specific molecular chaperones aid the folding of GPCRs. Chemical chaperones have been shown to be able to correct the misfolding in mutant GPCRs, proving to be important tools for studying the structure-function relationship of GPCRs. However, their potential therapeutic value is very limited. Pharmacological chaperones (pharmacoperones) are potentially important novel therapeutics for treating genetic diseases caused by mutations in GPCR genes that resulted in misfolded mutant proteins. Pharmacoperones also increase cell surface expression of wild-type GPCRs; therefore, they could be used to treat diseases that do not harbor mutations in GPCRs. Recent studies have shown that indeed pharmacoperones work in both experimental animals and patients. High-throughput assays have been developed to identify new pharmacoperones that could be used as therapeutics for a number of endocrine and other genetic diseases.
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Affiliation(s)
- Ya-Xiong Tao
- Department of Anatomy, Physiology, and Pharmacology (Y.-X.T.), College of Veterinary Medicine, Auburn University, Auburn, Alabama 36849-5519; and Departments of Internal Medicine and Cell Biology (P.M.C.), Texas Tech University Health Science Center, Lubbock, Texas 79430-6252
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27
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Lackman JJ, Markkanen PMH, Hogue M, Bouvier M, Petäjä-Repo UE. N-Glycan-dependent and -independent quality control of human δ opioid receptor N-terminal variants. J Biol Chem 2014; 289:17830-42. [PMID: 24798333 DOI: 10.1074/jbc.m114.566273] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Quality control (QC) in the endoplasmic reticulum (ER) scrutinizes newly synthesized proteins and directs them either to ER export or ER-associated degradation (ERAD). Here, we demonstrate that the human δ-opioid receptor (hδOR) is subjected to ERQC in both N-glycan-dependent and -independent manners. This was shown by investigating the biosynthesis and trafficking of wild-type and non-N-glycosylated F27C variants in metabolic pulse-chase assays coupled with flow cytometry and cell surface biotinylation. Both QC mechanisms distinguished the minute one-amino acid difference between the variants, targeting a large fraction of hδOR-Cys(27) to ERAD. However, the N-glycan-independent QC was unable to compensate the N-glycan-dependent pathway, and some incompletely folded non-N-glycosylated hδOR-Cys(27) reached the cell surface in conformation incompatible with ligand binding. The turnover of receptors associating with the molecular chaperone calnexin (CNX) was significantly slower for the hδOR-Cys(27), pointing to an important role of CNX in the hδOR N-glycan-dependent QC. This was further supported by the fact that inhibiting the co-translational interaction of hδOR-Cys(27) precursors with CNX led to their ERAD. Opioid receptor pharmacological chaperones released the CNX-bound receptors to ER export and, furthermore, were able to rescue the Cys(27) variant from polyubiquitination and retrotranslocation to the cytosol whether carrying N-glycans or not. Taken together, the hδOR appears to rely primarily on the CNX-mediated N-glycan-dependent QC that has the capacity to assist in folding, whereas the N-glycan-independent mechanism constitutes an alternative, although less accurate, system for directing misfolded/incompletely folded receptors to ERAD, possibly in altered cellular conditions.
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Affiliation(s)
- Jarkko J Lackman
- From the Department of Anatomy and Cell Biology and the Medical Research Center Oulu, Institute of Biomedicine, University of Oulu, FI-90014 Oulu, Finland and
| | - Piia M H Markkanen
- From the Department of Anatomy and Cell Biology and the Medical Research Center Oulu, Institute of Biomedicine, University of Oulu, FI-90014 Oulu, Finland and
| | - Mireille Hogue
- the Department of Biochemistry, Institute for Research in Immunology and Cancer and Groupe de Recherche Universitaire sur le Médicament, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Michel Bouvier
- the Department of Biochemistry, Institute for Research in Immunology and Cancer and Groupe de Recherche Universitaire sur le Médicament, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Ulla E Petäjä-Repo
- From the Department of Anatomy and Cell Biology and the Medical Research Center Oulu, Institute of Biomedicine, University of Oulu, FI-90014 Oulu, Finland and
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28
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Uchinashi Y, Tanaka K, Manabe Y, Fujimoto Y, Fukase K. Practical and Efficient Method for α-Sialylation with an Azide Sialyl Donor Using a Microreactor. J Carbohydr Chem 2014. [DOI: 10.1080/07328303.2014.880116] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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29
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Petäjä-Repo UE, Lackman JJ. Targeting opioid receptors with pharmacological chaperones. Pharmacol Res 2013; 83:52-62. [PMID: 24355364 DOI: 10.1016/j.phrs.2013.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 12/05/2013] [Accepted: 12/05/2013] [Indexed: 11/29/2022]
Abstract
G protein-coupled receptors (GPCRs) are polytopic membrane proteins that have a pivotal role in cellular signaling. Like other membrane proteins, they fold in the endoplasmic reticulum (ER) before they are transported to the plasma membrane. The ER quality control monitors the folding process and misfolded proteins and slowly folding intermediates are targeted to degradation in the cytosol via the ubiquitin-proteasome pathway. The high efficiency of the quality control machinery may lead to the disposal of potentially functional receptors. This is the major underlying course for loss-of-function conformational diseases, such as retinitis pigmentosa, nephrogenic diabetes insipidus and early onset obesity, which involve mutant GPCRs. During the past decade, it has become increasingly evident that small-molecular lipophilic and pharmacologically selective receptor ligands, called pharmacological chaperones (PCs), can rescue these mutant receptors from degradation by stabilizing newly synthesized receptors in the ER and enhancing their transport to the cell surface. This has raised the interesting prospect that PCs might have therapeutic value for the treatment of conformational diseases. At the same time, accumulating evidence has indicated that wild-type receptors might also be targeted by PCs, widening their therapeutic potential. This review focuses on one GPCR subfamily, opioid receptors that have been useful models to unravel the mechanism of action of PCs. In contrast to most other GPCRs, compounds that act as PCs for opioid receptors, including widely used opioid drugs, target wild-type receptors and their common natural variants.
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Affiliation(s)
- Ulla E Petäjä-Repo
- Department of Anatomy and Cell Biology and Medical Research Center Oulu, Institute of Biomedicine, University of Oulu, FI-90014 Oulu, Finland.
| | - Jarkko J Lackman
- Department of Anatomy and Cell Biology and Medical Research Center Oulu, Institute of Biomedicine, University of Oulu, FI-90014 Oulu, Finland
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Allele-specific N-glycosylation delays human surfactant protein B secretion in vitro and associates with decreased protein levels in vivo. Pediatr Res 2013; 74:646-51. [PMID: 24002332 DOI: 10.1038/pr.2013.151] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 04/18/2013] [Indexed: 11/09/2022]
Abstract
BACKGROUND Surfactant protein B (SP-B) is essential for normal lung function, and decreased concentrations of SP-B have a deleterious effect on pulmonary outcome. SP-B levels may correlate with variations in the encoding gene (SFTPB). SFTPB single-nucleotide polymorphism Ile131Thr affects proSP-B N-glycosylation in humans and the glycosylated Thr variant associates with pulmonary diseases. METHODS We analyzed SP-B levels in amniotic fluid samples for associations with SFTPB polymorphisms and generated cell lines expressing either proSP-B/131Ile or proSP-B/131Thr for examining the effect of glycosylation on proSP-B secretion kinetics. To determine any transcription preference between Ile131Thr allelic variants, we used heterozygous human lungs for allelic expression imbalance assays. RESULTS Protein levels correlated with Ile131Thr genotype and the lowest SP-B levels were observed in Thr/Thr homozygotes. Our results suggest that Ile131Thr variation-dependent N-glycosylation associates with decreased levels of SP-B, which is secreted from fetal lung to amniotic fluid. Glycosylated proSP-B/131Thr was secreted from transfected cells at a lower rate than nonglycosylated proSP-B/131Ile. Expression levels of the mRNA variants were equal. Secretion of the glycosylated variant was thus delayed in vitro by a posttranscriptional mechanism. CONCLUSION These data support the hypothesis that proSP-B glycosylation due to Ile131Thr variation may have a causal role in genetic susceptibility to acute respiratory distress.
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31
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Xu J, Xu M, Brown T, Rossi GC, Hurd YL, Inturrisi CE, Pasternak GW, Pan YX. Stabilization of the μ-opioid receptor by truncated single transmembrane splice variants through a chaperone-like action. J Biol Chem 2013; 288:21211-21227. [PMID: 23760268 DOI: 10.1074/jbc.m113.458687] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The μ-opioid receptor gene, OPRM1, undergoes extensive alternative pre-mRNA splicing, as illustrated by the identification of an array of splice variants generated by both 5' and 3' alternative splicing. The current study reports the identification of another set of splice variants conserved across species that are generated through exon skipping or insertion that encodes proteins containing only a single transmembrane (TM) domain. Using a Tet-Off system, we demonstrated that the truncated single TM variants can dimerize with the full-length 7-TM μ-opioid receptor (MOR-1) in the endoplasmic reticulum, leading to increased expression of MOR-1 at the protein level by a chaperone-like function that minimizes endoplasmic reticulum-associated degradation. In vivo antisense studies suggested that the single TM variants play an important role in morphine analgesia, presumably through modulation of receptor expression levels. Our studies suggest the functional roles of truncated receptors in other G protein-coupled receptor families.
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Affiliation(s)
- Jin Xu
- From the Department of Neurology and the Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065
| | - Ming Xu
- From the Department of Neurology and the Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065
| | - Taylor Brown
- From the Department of Neurology and the Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065
| | - Grace C Rossi
- the Department of Psychology, CW Post College, Long Island University, Brookville, New York 11568
| | - Yasmin L Hurd
- the Department of Psychiatry and Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York 10029, and
| | - Charles E Inturrisi
- the Department of Pharmacology, Weill Cornell Medical College, New York, New York 10065
| | - Gavril W Pasternak
- From the Department of Neurology and the Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065,; the Department of Pharmacology, Weill Cornell Medical College, New York, New York 10065.
| | - Ying-Xian Pan
- From the Department of Neurology and the Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065,.
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Breitwieser GE. Minireview: the intimate link between calcium sensing receptor trafficking and signaling: implications for disorders of calcium homeostasis. Mol Endocrinol 2012; 26:1482-95. [PMID: 22745192 DOI: 10.1210/me.2011-1370] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The calcium-sensing receptor (CaSR) regulates organismal Ca(2+) homeostasis. Dysregulation of CaSR expression or mutations in the CASR gene cause disorders of Ca(2+) homeostasis and contribute to the progression or severity of cancers and cardiovascular disease. This brief review highlights recent findings that define the CaSR life cycle, which controls the cellular abundance of CaSR and CaSR signaling. A novel mechanism, termed agonist-driven insertional signaling (ADIS), contributes to the unique hallmarks of CaSR signaling, including the high degree of cooperativity and the lack of functional desensitization. Agonist-mediated activation of plasma membrane-localized CaSR increases the rate of insertion of CaSR at the plasma membrane without altering the constitutive endocytosis rate, thereby acutely increasing the maximum signaling response. Prolonged CaSR signaling requires a large intracellular ADIS-mobilizable pool of CaSR, which is maintained by signaling-mediated increases in biosynthesis. This model provides a rational framework for characterizing the defects caused by CaSR mutations and the altered functional expression of wild-type CaSR in disease states. Mechanistic dissection of ADIS of CaSR should lead to optimized pharmacological approaches to normalize CaSR signaling in disorders of Ca(2+) homeostasis.
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Affiliation(s)
- Gerda E Breitwieser
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania 17822-2604, USA.
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Gellynck E, Andressen KW, Lintermans B, Haegeman G, Levy FO, Vanhoenacker P, Van Craenenbroeck K. Biochemical and pharmacological study of N-linked glycosylation of the human serotonin 5-HT₇a receptor. FEBS J 2012; 279:1994-2003. [PMID: 22448645 DOI: 10.1111/j.1742-4658.2012.08581.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The 5-hydroxytryptamine (5-HT)(7(a)) receptor is a G-protein-coupled receptor critically involved in human psychiatric and neurological disorders. In the present study, we evaluate the presence and the functional role of N-glycosylation of the human 5-HT(7) receptor. Western blot analysis of HEK293T cells transiently expressing the 5-HT(7(a)) receptor in the presence of tunicamycin gave rise to a band shift, indicating the existence of an N-glycosylated form of the 5-HT(7(a)) receptor. To further investigate this, we mutated the two predicted N-glycosylation sites (N5Q and N66Q) and compared the molecular mass of the immunoreactive bands with those of the wild-type receptor, indicating that both asparagines were N-glycosylated. The mutant receptors had the same binding affinity for [(3) H]5-CT and the same potency and efficacy with regard to 5-HT-induced activation of adenylyl cyclase. However, there was a reduction in maximal ligand binding for the single and double mutants compared to the wild-type receptor. Next, membrane labelling and immunocytochemical studies demonstrated that the N-glycosylation mutants were expressed at the cell surface. We conclude that N-glycosylation is not important for cell surface expression of the 5-HT(7) receptor.
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Affiliation(s)
- Evelien Gellynck
- Laboratory for Eukaryotic Gene Expression and Signal Transduction (LEGEST), Ghent University, Belgium
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Ohgomori T, Nanao T, Morita A, Ikekita M. Asn54-linked glycan is critical for functional folding of intercellular adhesion molecule-5. Glycoconj J 2011; 29:47-55. [PMID: 22187327 DOI: 10.1007/s10719-011-9363-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 11/21/2011] [Accepted: 11/28/2011] [Indexed: 11/24/2022]
Abstract
Intercellular adhesion molecule-5 (ICAM-5, telencephalin) is a dendritically polarized type I membrane glycoprotein, and promotes dendritic filopodia formation. Although we have determined the N-glycan structures of ICAM-5 in a previous report, their function is unknown. Here, we produced fifteen ICAM-5 gene constructs, in which each potential N-glycosylation site was mutated, to elucidate the function of the N-glycans of ICAM-5, and observed the effects of transfection of them on a neuronal cell line, Neuro-2a (N2a). Only the N54Q mutant, which is the mutant for the most N-terminal glycosylation site, failed to induce filopodia-like protrusions in N2a cells. Immunofluorescence staining and cell surface biotinylation revealed that N54Q ICAM-5 was confined to the ER and also could not be expressed on the cell surface. This is further supported by the biochemical evidence that almost all N-glycans of N54Q ICAM-5 were digested by Endo glycosidase H and peptide:N-glycanase, indicating that almost all of them retain high-mannose-type structures in ER. In additon, it also failed to form disulfide bonds or functional protein complexes. The stable transformants of N54Q ICAM-5 showed retarded cell growth, but it was interesting that there was no apparent ER stress, because the mutant was sequentially degraded via ER associated degradation pathway by comparing the susceptibilities of the responses to various inhibitors of this pathway in wild-type and N54Q ICAM-5 transfectants. Taken together, the Asn(54)-linked glycan is necessary for normal trafficking and function of ICAM-5, but is unassociated with ER-associated degradation of it.
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Affiliation(s)
- Tomohiro Ohgomori
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Yamazaki, Noda, Chiba, Japan.
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Leskelä TT, Lackman JJ, Vierimaa MM, Kobayashi H, Bouvier M, Petäjä-Repo UE. Cys-27 variant of human δ-opioid receptor modulates maturation and cell surface delivery of Phe-27 variant via heteromerization. J Biol Chem 2011; 287:5008-20. [PMID: 22184124 DOI: 10.1074/jbc.m111.305656] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The important role of G protein-coupled receptor homo/heteromerization in receptor folding, maturation, trafficking, and cell surface expression has become increasingly evident. Here we investigated whether the human δ-opioid receptor (hδOR) Cys-27 variant that shows inherent compromised maturation has an effect on the behavior of the more common Phe-27 variant in the early secretory pathway. We demonstrate that hδOR-Cys-27 acts in a dominant negative manner and impairs cell surface delivery of the co-expressed hδOR-Phe-27 and impairs conversion of precursors to the mature form. This was demonstrated by metabolic labeling, Western blotting, flow cytometry, and confocal microscopy in HEK293 and human SH-SY5Y neuroblastoma cells using differentially epitope-tagged variants. The hδOR-Phe-27 precursors that were redirected to the endoplasmic reticulum-associated degradation were, however, rescued by a pharmacological chaperone, the opioid antagonist naltrexone. Co-immunoprecipitation of metabolically labeled variants revealed that both endoplasmic reticulum-localized precursors and mature receptors exist as homo/heteromers. The existence of homo/heteromers was confirmed in living cells by bioluminescence resonance energy transfer measurements, showing that the variants have a similar propensity to form homo/heteromers. By forming both homomers and heteromers, the hδOR-Cys-27 variant may thus regulate the levels of receptors at the cell surface, possibly leading to altered responsiveness to opioid ligands in individuals carrying the Cys-27 variant.
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Affiliation(s)
- Tarja T Leskelä
- Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, FI-90014 Oulu, Finland
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36
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Salom D, Cao P, Sun W, Kramp K, Jastrzebska B, Jin H, Feng Z, Palczewski K. Heterologous expression of functional G-protein-coupled receptors in Caenorhabditis elegans. FASEB J 2011; 26:492-502. [PMID: 22090314 DOI: 10.1096/fj.11-197780] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
New strategies for expression, purification, functional characterization, and structural determination of membrane-spanning G-protein-coupled receptors (GPCRs) are constantly being developed because of their importance to human health. Here, we report a Caenorhabditis elegans heterologous expression system able to produce milligram amounts of functional native and engineered GPCRs. Both bovine opsin [(b)opsin] and human adenosine A(2A) subtype receptor [(h)A(2A)R] expressed in neurons or muscles of C. elegans were localized to cell membranes. Worms expressing these GPCRs manifested changes in motor behavior in response to light and ligands, respectively. With a newly devised protocol, 0.6-1 mg of purified homogenous 9-cis-retinal-bound bovine isorhodopsin [(b)isoRho] and ligand-bound (h)A(2A)R were obtained from C. elegans from one 10-L fermentation at low cost. Purified recombinant (b)isoRho exhibited its signature absorbance spectrum and activated its cognate G-protein transducin in vitro at a rate similar to native rhodopsin (Rho) obtained from bovine retina. Generally high expression levels of 11 native and mutant GPCRs demonstrated the potential of this C. elegans system to produce milligram quantities of high-quality GPCRs and possibly other membrane proteins suitable for detailed characterization.
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Romero-Fernandez W, Borroto-Escuela DO, Perez Alea M, Garcia-Mesa Y, Garriga P. Altered trafficking and unfolded protein response induction as a result of M3 muscarinic receptor impaired N-glycosylation. Glycobiology 2011; 21:1663-72. [DOI: 10.1093/glycob/cwr105] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Protein quality control at the plasma membrane. Curr Opin Cell Biol 2011; 23:483-91. [PMID: 21571517 DOI: 10.1016/j.ceb.2011.04.012] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Revised: 04/12/2011] [Accepted: 04/19/2011] [Indexed: 12/22/2022]
Abstract
Cellular proteostasis (or protein homeostasis) depends on the timely folding and disposal of conformationally damaged polypeptides during their life span at all subcellular locations. This process is particularly important for membrane proteins confined to the cell surface with crucial regulatory role in cellular homoeostasis and intercellular communication. Accumulating evidences indicate that membrane proteins exported from the endoplasmic reticulum (ER) are subjected to peripheral quality control (QC) along the late secretory and endocytic pathways, as well as at the plasma membrane (PM). Recently identified components of the PM QC recognition and effector mechanisms responsible for ubiquitination and lysosomal degradation of conformationally damaged PM proteins uncovered striking similarities to and differences from that of the ER QC machinery. Possible implications of the peripheral protein QC activity in phenotypic modulation of conformational diseases are also outlined.
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Cysteine 27 variant of the delta-opioid receptor affects amyloid precursor protein processing through altered endocytic trafficking. Mol Cell Biol 2011; 31:2326-40. [PMID: 21464208 DOI: 10.1128/mcb.05015-11] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Agonist-induced activation of the δ-opioid receptor (δOR) was recently shown to augment β- and γ-secretase activities, which increased the production of β-amyloid peptide (Aβ), known to accumulate in the brain tissues of Alzheimer's disease (AD) patients. Previously, the δOR variant with a phenylalanine at position 27 (δOR-Phe27) exhibited more efficient receptor maturation and higher stability at the cell surface than did the less common cysteine (δOR-Cys27) variant. For this study, we expressed these variants in human SH-SY5Y and HEK293 cells expressing exogenous or endogenous amyloid precursor protein (APP) and assessed the effects on APP processing. Expression of δOR-Cys27, but not δOR-Phe27, resulted in a robust accumulation of the APP C83 C-terminal fragment and the APP intracellular domain, while the total soluble APP and, particularly, the β-amyloid 40 levels were decreased. These changes upon δOR-Cys27 expression coincided with decreased localization of APP C-terminal fragments in late endosomes and lysosomes. Importantly, a long-term treatment with a subset of δOR-specific ligands or a c-Src tyrosine kinase inhibitor suppressed the δOR-Cys27-induced APP phenotype. These data suggest that an increased constitutive internalization and/or concurrent signaling of the δOR-Cys27 variant affects APP processing through altered endocytic trafficking of APP.
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Hakalahti AE, Vierimaa MM, Lilja MK, Kumpula EP, Tuusa JT, Petäjä-Repo UE. Human beta1-adrenergic receptor is subject to constitutive and regulated N-terminal cleavage. J Biol Chem 2010; 285:28850-61. [PMID: 20587416 DOI: 10.1074/jbc.m110.149989] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The beta(1)-adrenergic receptor (beta(1)AR) is the predominant betaAR in the heart, mediating the catecholamine-stimulated increase in cardiac rate and force of contraction. Regulation of this important G protein-coupled receptor is nevertheless poorly understood. We describe here the biosynthetic profile of the human beta(1)AR and reveal novel features relevant to its regulation using an inducible heterologous expression system in HEK293(i) cells. Metabolic pulse-chase labeling and cell surface biotinylation assays showed that the synthesized receptors are efficiently and rapidly transported to the cell surface. The N terminus of the mature receptor is extensively modified by sialylated mucin-type O-glycosylation in addition to one N-glycan attached to Asn(15). Furthermore, the N terminus was found to be subject to limited proteolysis, resulting in two membrane-bound C-terminal fragments. N-terminal sequencing of the fragments identified two cleavage sites between Arg(31) and Leu(32) and Pro(52) and Leu(53), which were confirmed by cleavage site and truncation mutants. Metalloproteinase inhibitors were able to inhibit the cleavage, suggesting that it is mediated by a matrix metalloproteinase or a disintegrin and metalloproteinase (ADAM) family member. Most importantly, the N-terminal cleavage was found to occur not only in vitro but also in vivo. Receptor activation mediated by the betaAR agonist isoproterenol enhanced the cleavage in a concentration- and time-dependent manner, and it was also enhanced by direct stimulation of protein kinase C and adenylyl cyclase. Mutation of the Arg(31)-Leu(32) cleavage site stabilized the mature receptor. We hypothesize that the N-terminal cleavage represents a novel regulatory mechanism of cell surface beta(1)ARs.
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Affiliation(s)
- Anna E Hakalahti
- Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, FI-90014 Oulu, Finland
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Tuusa JT, Leskelä TT, Petäjä-Repo UE. Human delta opioid receptor biogenesis is regulated via interactions with SERCA2b and calnexin. FEBS J 2010; 277:2815-29. [PMID: 20528919 DOI: 10.1111/j.1742-4658.2010.07699.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Sarco(endo)plasmic reticulum calcium ATPase (SERCA)2b maintains the cellular Ca(2+) homeostasis by transferring Ca(2+) from the cytosol to the lumen of the endoplasmic reticulum (ER). Recently, SERCA2b has also been shown to be involved in the biosynthesis of secreted and membrane proteins via direct protein-protein interactions, involving components of the ER folding and quality-control machinery, as well as newly synthesized G protein-coupled receptors. Here we demonstrate that the human delta opioid receptor (hdeltaOR) exists in a ternary complex with SERCA2b and the ER molecular chaperone calnexin. The interaction between SERCA2b and hdeltaOR in vivo did not require calnexin as it was independent of the C-terminal calnexin-interacting domain of SERCA2b. However, the receptor was able to mediate co-immunoprecipitation of calnexin with the C-terminally truncated SERCA2b. The association of SERCA2b with hdeltaOR was regulated in vitro by Ca(2+) and ATP in a manner that was opposite to the calnexin-hdeltaOR interaction. Importantly, co-expression of the catalytically inactive SERCA2b(D351A) or calnexin binding-compromised SERCA2bDeltaC mutants with the receptor decreased the expression of mature receptors in a manner that did not directly relate to changes in the ER Ca(2+) concentration. We conclude that dynamic interactions among SERCA2b, calnexin and the hdeltaOR precursor orchestrate receptor biogenesis and are regulated by Ca(2+) and ATP. We further hypothesize that the primary role of SERCA2b in this process is to act as a Ca(2+) sensor in the vicinity of active translocons, integrating protein folding with local fluctuations of ER Ca(2+) levels.
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Affiliation(s)
- Jussi T Tuusa
- Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu, Finland
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Cavanaugh A, McKenna J, Stepanchick A, Breitwieser GE. Calcium-sensing receptor biosynthesis includes a cotranslational conformational checkpoint and endoplasmic reticulum retention. J Biol Chem 2010; 285:19854-64. [PMID: 20421307 DOI: 10.1074/jbc.m110.124792] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Metabolic labeling with [(35)S]cysteine was used to characterize early events in CaSR biosynthesis. [(35)S]CaSR is relatively stable (half-life approximately 8 h), but maturation to the final glycosylated form is slow and incomplete. Incorporation of [(35)S]cysteine is linear over 60 min, and the rate of [(35)S]CaSR biosynthesis is significantly increased by the membrane-permeant allosteric agonist NPS R-568, which acts as a cotranslational pharmacochaperone. The [(35)S]CaSR biosynthetic rate also varies as a function of conformational bias induced by loss- or gain-of-function mutations. In contrast, [(35)S]CaSR maturation to the plasma membrane was not significantly altered by exposure to the pharmacochaperone NPS R-568, the allosteric agonist neomycin, or the orthosteric agonist Ca(2+) (0.5 or 5 mm), suggesting that CaSR does not control its own release from the endoplasmic reticulum. A CaSR chimera containing the mGluR1alpha carboxyl terminus matures completely (half-time of approximately 8 h) and without a lag period, as does the truncation mutant CaSRDelta868 (half-time of approximately 16 h). CaSRDelta898 exhibits maturation comparable with full-length CaSR, suggesting that the CaSR carboxyl terminus between residues Thr(868) and Arg(898) limits maturation. Overall, these results suggest that CaSR is subject to cotranslational quality control, which includes a pharmacochaperone-sensitive conformational checkpoint. The CaSR carboxyl terminus is the chief determinant of intracellular retention of a significant fraction of total CaSR. Intracellular CaSR may reflect a rapidly mobilizable "storage form" of CaSR and/or may subserve distinct intracellular signaling roles that are sensitive to signaling-dependent changes in endoplasmic reticulum Ca(2+) and/or glutathione.
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Affiliation(s)
- Alice Cavanaugh
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania 17822, USA
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Rozwandowicz-Jansen A, Laurila J, Martikkala E, Frang H, Hemmilä I, Scheinin M, Hänninen P, Härmä H. Homogeneous GTP binding assay employing QRET technology. ACTA ACUST UNITED AC 2010; 15:261-7. [PMID: 20103692 DOI: 10.1177/1087057109358921] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Functional cell signaling assays have become important tools for measuring ligand-induced receptor activation in cell-based biomolecular screening. Guanosine-5'-triphosphate (GTP) is a generic signaling marker responsible for the first intracellular signaling event of the G-protein-coupled receptors (GPCRs). [(35)S]GTPgammaS binding assay is the classical well-established method for measuring agonist-induced G-protein activation requiring a separation of free and bound fractions prior to measurement. Here a novel, separation-free, time-resolved fluorescence GTP binding assay has been developed based on a non-fluorescence resonance energy transfer (FRET) single-label approach and quenching of a nonbound europium-labeled, nonhydrolyzable GTP analog (Eu-GTP). The quenching resonance energy transfer (QRET) method relies on the use of Eu-GTP, providing a time-resolved fluorescent detection as an alternative to the radiolabel [(35)S]GTPgammaS assay. Upon activation of recombinant human alpha(2A)-adrenoceptors (alpha(2A)-AR) expressed in Chinese hamster ovary cells, guanosine-5'-diphosphate is released from the alpha-subunit of Gi-proteins, enabling the subsequent binding of Eu-GTP. Activation of alpha(2A)-AR with 5 different alpha(2)-AR agonists was measured quantitatively using the developed QRET GTP assay and compared to [(35)S]GTPgammaS and heterogeneous Eu-GTP filtration assays. Equal potencies and efficacy rank orders were observed in all 3 assays but with a lower signal-to-background ratio and increased assay variation in the QRET assay compared to the Eu-GTP filtration and the nonhomogeneous [(35)S]GTPgammaS binding assays.
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Abstract
This paper is the 31st consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2008 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, 65-30 Kissena Blvd, Flushing, NY 11367, United States.
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Zhang X, Bao L, Ma GQ. Sorting of neuropeptides and neuropeptide receptors into secretory pathways. Prog Neurobiol 2009; 90:276-83. [PMID: 19853638 DOI: 10.1016/j.pneurobio.2009.10.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2009] [Revised: 08/11/2009] [Accepted: 10/09/2009] [Indexed: 01/07/2023]
Abstract
There are two major secretory pathways in neurons, the regulated pathway and the constitutive pathway. Neuropeptides and other regulated secretory proteins are known to be sorted into large dense-core vesicles of the regulated pathway in the trans-Golgi network and are secreted upon stimulus-induced increases in intracellular Ca(2+). The newly synthesized cell surface receptors are usually sorted into microvesicles of the constitutive pathway and inserted into the plasma membrane by spontaneous exocytosis. Small-diameter sensory neurons in dorsal root ganglia and pheochromocytoma cells express neuropeptides (e.g., substance P) and several neuropeptide receptors including opioid receptors. The mu-opioid receptors are delivered to the cell surface through the constitutive pathway, whereas another type of opioid receptor, the delta-opioid receptor, is often found in the membrane of large dense-core vesicles and can be inserted into the plasma membrane when exocytosis occurs. Recent studies show that sequences with opposite electrical polarity within the prohormones of substance P are essential for their sorting into large dense-core vesicles. Moreover, the delta-opioid receptor is sorted into large dense-core vesicles by its interaction with protachykinin, a prohormone of substance P. These findings provide insight into the molecular mechanisms that determine the sorting and trafficking of neuropeptides and neuropeptide receptors in neurons.
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Affiliation(s)
- Xu Zhang
- Institute of Neuroscience and State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, PR China.
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Noorwez SM, Sama RRK, Kaushal S. Calnexin improves the folding efficiency of mutant rhodopsin in the presence of pharmacological chaperone 11-cis-retinal. J Biol Chem 2009; 284:33333-42. [PMID: 19801547 DOI: 10.1074/jbc.m109.043364] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The lectin chaperone calnexin (Cnx) is important for quality control of glycoproteins, and the chances of correct folding of a protein increase the longer the protein interacts with Cnx. Mutations in glycoproteins increase their association with Cnx, and these mutant proteins are retained in the endoplasmic reticulum. However, until now, the increased interaction with Cnx was not known to increase the folding of mutant glycoproteins. Because many human diseases result from glycoprotein misfolding, a Cnx-assisted folding of mutant glycoproteins could be beneficial. Mutations of rhodopsin, the glycoprotein pigment of rod photoreceptors, cause misfolding resulting in retinitis pigmentosa. Despite the critical role of Cnx in glycoprotein folding, surprisingly little is known about its interaction with rhodopsin or whether this interaction could be modulated to increase the folding of mutant rhodopsin. Here, we demonstrate that Cnx preferentially associates with misfolded mutant opsins associated with retinitis pigmentosa. Furthermore, the overexpression of Cnx leads to an increased accumulation of misfolded P23H opsin but not the correctly folded protein. Finally, we demonstrate that increased levels of Cnx in the presence of the pharmacological chaperone 11-cis-retinal increase the folding efficiency and result in an increase in correct folding of mutant rhodopsin. These results demonstrate that misfolded rather than correctly folded rhodopsin is a substrate for Cnx and that the interaction between Cnx and mutant, misfolded rhodopsin, can be targeted to increase the yield of folded mutant protein.
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Affiliation(s)
- Syed M Noorwez
- Department of Ophthalmology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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47
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Wang Q, Liu-Chen LY, Traynor JR. Differential modulation of mu- and delta-opioid receptor agonists by endogenous RGS4 protein in SH-SY5Y cells. J Biol Chem 2009; 284:18357-67. [PMID: 19416973 DOI: 10.1074/jbc.m109.015453] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Regulator of G-protein signaling (RGS) proteins are a family of molecules that control the duration of G protein signaling. A variety of RGS proteins have been reported to modulate opioid receptor signaling. Here we show that RGS4 is abundantly expressed in human neuroblastoma SH-SY5Y cells that endogenously express mu- and delta-opioid receptors and test the hypothesis that the activity of opioids in these cells is modulated by RGS4. Endogenous RGS4 protein was reduced by approximately 90% in SH-SY5Y cells stably expressing short hairpin RNA specifically targeted to RGS4. In these cells, the potency and maximal effect of delta-opioid receptor agonist (SNC80)-mediated inhibition of forskolin-stimulated cAMP accumulation was increased compared with control cells. This effect was reversed by transient transfection of a stable RGS4 mutant (HA-RGS4C2S). Furthermore, MAPK activation by SNC80 was increased in cells with knockdown of RGS4. In contrast, there was no change in the mu-opioid (morphine) response at adenylyl cyclase or MAPK. FLAG-tagged opioid receptors and HA-RGS4C2S were transiently expressed in HEK293T cells, and co-immunoprecipitation experiments showed that the delta-opioid receptor but not the mu-opioid receptor could be precipitated together with the stable RGS4. Using chimeras of the delta- and mu-opioid receptors, the C-tail and third intracellular domain of the delta-opioid receptor were suggested to be the sites of interaction with RGS4. The findings demonstrate a role for endogenous RGS4 protein in modulating delta-opioid receptor signaling in SH-SY5Y cells and provide evidence for a receptor-specific effect of RGS4.
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Affiliation(s)
- Qin Wang
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
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White E, McKenna J, Cavanaugh A, Breitwieser GE. Pharmacochaperone-mediated rescue of calcium-sensing receptor loss-of-function mutants. Mol Endocrinol 2009; 23:1115-23. [PMID: 19389809 DOI: 10.1210/me.2009-0041] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The calcium sensing receptor (CaSR) is a Family C/3 G protein-coupled receptor that translates changes in extracellular Ca(2+) into diverse intracellular signals. Loss-of-function mutations in human CaSR cause familial hypocalciuric hypercalcemia and neonatal severe hyperparathyroidism. CaSR must navigate a number of endoplasmic reticulum quality control checkpoints during biosynthesis, including a conformational/functional checkpoint. Here we examine the biosynthesis of 25 CaSR mutations causing familial hypocalciuric hypercalcemia /neonatal severe hyperparathyroidism using immunoprecipitation, biotinylation, and functional assays. We define classes of CaSR mutants based on their biosynthetic profile. Class I CaSR mutants are not rescued to the plasma membrane. To dissect the organellar compartments that class I mutants can access, we engineered a cleavage site for the proprotein convertase furin into the extracellular domain of wild-type CaSR and class I mutants. Based on absence or presence of cleavage fragments, we find most mutants are degraded from the endoplasmic reticulum (no furin-mediated cleavage), whereas others access the Golgi (furin-mediated cleavage) before degradation. Class II CaSR mutants show increased expression and/or enhanced plasma membrane localization upon treatment with MG132 or the pharmacochaperone NPS R-568, permitting assay of functional activity. Of the 10 CaSR mutants that exhibit plasma membrane localization, only two did not show enhanced functional activity after rescue with NPS R-568. The established approaches can be used with current and newly identified CaSR mutations to identify the location of biosynthetic block and to determine the likelihood of rescue by allosteric agonists.
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Affiliation(s)
- Elissa White
- Weis Center for Research, Geisinger Clinic, Danville, Pennsylvania 17822-2604, USA
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Salom D, Wu N, Sun W, Dong Z, Palczewski K, Jordan S, Salon JA. Heterologous expression and purification of the serotonin type 4 receptor from transgenic mouse retina. Biochemistry 2009; 47:13296-307. [PMID: 19053287 DOI: 10.1021/bi8018527] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Recent breakthroughs in the solution of X-ray structures for G protein-coupled receptors (GPCRs) with diffusible ligands have employed extensively mutated or recombined receptor fusion proteins heterologously expressed in conventional in vitro cell-based systems. While these advances now show that crystallization of non-rhodopsin members of this superfamily can be accomplished, the use of radically modified proteins may limit the relevance of the derived structures for precision-guided drug design. To better enable the study of native GPCR structures, we report here efforts to engineer an in vivo expression system that harnesses the photoreceptor system of the retina to express heterologous GPCRs with native human sequences in a biochemically homogeneous and pharmacologically functional conformation. As an example, we show that the human 5HT4 receptor, when placed under the influence of the mouse opsin promoter and an opsin rod outer segment (ROS) targeting sequence, localized to ROS of transgenic mouse retina. The resulting receptor protein was uniformly glycosylated and pharmacologically intact as demonstrated by immunoblotting and radioligand binding assays. Upon solubilization, the retinal 5HT4 receptor retained the binding properties of its initial state in retinal membranes. With the engineered T7 monoclonal epitope sequence, the solubilized receptor was easily purified by one-step immunoaffinity chromatography and the purified receptor in detergent solution preserved its ligand binding properties. This expression method may prove generally useful for generating functional, high-quality GPCR protein.
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Affiliation(s)
- David Salom
- Polgenix Inc., 11000 Cedar Avenue, Suite 260, Cleveland, Ohio 44106, USA
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Leskelä TT, Markkanen PMH, Alahuhta IA, Tuusa JT, Petäjä-Repo UE. Phe27Cys Polymorphism Alters the Maturation and Subcellular Localization of the Human δ Opioid Receptor. Traffic 2008; 10:116-29. [DOI: 10.1111/j.1600-0854.2008.00846.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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