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Yi W, Hu M, Shi L, Li T, Bai C, Sun F, Ma H, Zhao Z, Yan S. Whole genome sequencing identified genomic diversity and candidated genes associated with economic traits in Northeasern Merino in China. Front Genet 2024; 15:1302222. [PMID: 38333624 PMCID: PMC10851152 DOI: 10.3389/fgene.2024.1302222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 01/12/2024] [Indexed: 02/10/2024] Open
Abstract
Introduction: Northeast Merino (NMS) is a breed developed in Northeast China during the 1960s for wool and meat production. It exhibits excellent traits such as high wool yield, superior meat quality, rapid growth rate, robust disease resistance, and adaptability to cold climates. However, no studies have used whole-genome sequencing data to investigate the superior traits of NMS. Methods: In this study, we investigated the population structure, genetic diversity, and selection signals of NMS using whole-genome sequencing data from 20 individuals. Two methods (integrated haplotype score and composite likelihood ratio) were used for selection signal analysis, and the Fixation Index was used to explore the selection signals of NMS and the other two breeds, Mongolian sheep and South African meat Merino. Results: The results showed that NMS had low inbreeding levels, high genomic diversity, and a pedigree of both Merino breeds and Chinese local breeds. A total length of 14.09 Mb genomic region containing 287 genes was detected using the two methods. Further exploration of the functions of these genes revealed that they are mainly concentrated in wool production performance (IRF2BP2, MAP3K7, and WNT3), meat production performance (NDUFA9, SETBP1, ZBTB38, and FTO), cold resistance (DNAJC13, LPGAT1, and PRDM16), and immune response (PRDM2, GALNT8, and HCAR2). The selection signals of NMS and the other two breeds annotated 87 and 23 genes, respectively. These genes were also mainly focused on wool and meat production performance. Conclusion: These results provide a basis for further breeding improvement, comprehensive use of this breed, and a reference for research on other breeds.
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Affiliation(s)
- Wenfeng Yi
- College of Animal Science, Jilin University, Changchun, China
| | - Mingyue Hu
- College of Animal Science, Jilin University, Changchun, China
| | - Lulu Shi
- College of Animal Science, Jilin University, Changchun, China
| | - Ting Li
- College of Animal Science, Jilin University, Changchun, China
| | - Chunyan Bai
- College of Animal Science, Jilin University, Changchun, China
| | - Fuliang Sun
- College of Agriculture, Yanbian University, Yanji, China
| | - Huihai Ma
- Institute of Animal Husbandry and Veterinary, Jilin Academy of Agricultural Sciences, Gongzhuling, China
| | - Zhongli Zhao
- Institute of Animal Husbandry and Veterinary, Jilin Academy of Agricultural Sciences, Gongzhuling, China
| | - Shouqing Yan
- College of Animal Science, Jilin University, Changchun, China
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Stephan G, Frenster JD, Liebscher I, Placantonakis DG. Activation of the adhesion G protein-coupled receptor GPR133 by antibodies targeting its N-terminus. J Biol Chem 2022; 298:101949. [PMID: 35447113 PMCID: PMC9133650 DOI: 10.1016/j.jbc.2022.101949] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 04/03/2022] [Accepted: 04/05/2022] [Indexed: 11/28/2022] Open
Abstract
We recently demonstrated that GPR133 (ADGRD1), an adhesion G protein-coupled receptor involved in raising cytosolic cAMP levels, is necessary for growth of glioblastoma (GBM) and is de novo expressed in GBM relative to normal brain tissue. Our previous work suggested that dissociation of autoproteolytically generated N-terminal and C-terminal fragments of GPR133 at the plasma membrane correlates with receptor activation and signaling. To promote the goal of developing biologics that modulate GPR133 function, we investigated the effects of antibodies against the N-terminus of GPR133 on receptor signaling. Here, we show that treatment of HEK293T cells overexpressing GPR133 with these antibodies increased cAMP levels in a concentration-dependent manner. Analysis of culture medium following antibody treatment further indicated the presence of complexes of these antibodies with the autoproteolytically cleaved N-terminal fragments of GPR133. In addition, cells expressing a cleavage-deficient mutant of GPR133 (H543R) did not respond to antibody stimulation, suggesting that the effect is cleavage dependent. Finally, we demonstrate the antibody-mediated stimulation of WT GPR133, but not the cleavage-deficient H543R mutant, was reproducible in patient-derived GBM cells. These findings provide a paradigm for modulation of GPR133 function with biologics and support the hypothesis that the intramolecular cleavage in the N-terminus modulates receptor activation and signaling.
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Affiliation(s)
- Gabriele Stephan
- Department of Neurosurgery, NYU Grossman School of Medicine, New York, New York, USA.
| | - Joshua D Frenster
- Department of Neurosurgery, NYU Grossman School of Medicine, New York, New York, USA
| | - Ines Liebscher
- Rudolf Schönheimer Institute for Biochemistry, Molecular Biochemistry, University of Leipzig, Leipzig, Germany
| | - Dimitris G Placantonakis
- Department of Neurosurgery, NYU Grossman School of Medicine, New York, New York, USA; Kimmel Center for Stem Cell Biology, NYU Grossman School of Medicine, New York, New York, USA; Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, New York, New York, USA; Brain and Spine Tumor Center, NYU Grossman School of Medicine, New York, New York, USA; Neuroscience Institute, NYU Grossman School of Medicine, New York, New York, USA.
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3
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Abstract
Mutations of polycystin-1 (PC1) are the major cause (85% of cases) of autosomal dominant polycystic kidney disease (ADPKD), which is the fourth leading cause of kidney failure. PC1 is thought to function as an atypical G protein-coupled receptor, yet the mechanism by which PC1 regulates G-protein signaling remains poorly understood. A significant portion of ADPKD mutations of PC1 encode a protein with defects in maturation or reduced function that may be amenable to functional rescue. In this work, we have combined complementary biochemical and cellular assay experiments and accelerated molecular simulations, which revealed an allosteric transduction pathway in activation of the PC1 C-terminal fragment. Our findings will facilitate future rational drug design efforts targeting the PC1 signaling function. Polycystin-1 (PC1) is an important unusual G protein-coupled receptor (GPCR) with 11 transmembrane domains, and its mutations account for 85% of cases of autosomal dominant polycystic kidney disease (ADPKD). PC1 shares multiple characteristics with Adhesion GPCRs. These include a GPCR proteolysis site that autocatalytically divides these proteins into extracellular, N-terminal, and membrane-embedded, C-terminal fragments (CTF), and a tethered agonist (TA) within the N-terminal stalk of the CTF that is suggested to activate signaling. However, the mechanism by which a TA can activate PC1 is not known. Here, we have combined functional cellular signaling experiments of PC1 CTF expression constructs encoding wild type, stalkless, and three different ADPKD stalk variants with all-atom Gaussian accelerated molecular dynamics (GaMD) simulations to investigate TA-mediated signaling activation. Correlations of residue motions and free-energy profiles calculated from the GaMD simulations correlated with the differential signaling abilities of wild type and stalk variants of PC1 CTF. They suggested an allosteric mechanism involving residue interactions connecting the stalk, Tetragonal Opening for Polycystins (TOP) domain, and putative pore loop in TA-mediated activation of PC1 CTF. Key interacting residues such as N3074–S3585 and R3848–E4078 predicted from the GaMD simulations were validated by mutagenesis experiments. Together, these complementary analyses have provided insights into a TA-mediated activation mechanism of PC1 CTF signaling, which will be important for future rational drug design targeting PC1.
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4
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Rosa M, Noel T, Harris M, Ladds G. Emerging roles of adhesion G protein-coupled receptors. Biochem Soc Trans 2021; 49:1695-1709. [PMID: 34282836 PMCID: PMC8421042 DOI: 10.1042/bst20201144] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 12/24/2022]
Abstract
Adhesion G protein-coupled receptors (aGPCRs) form a sub-group within the GPCR superfamily. Their distinctive structure contains an abnormally large N-terminal, extracellular region with a GPCR autoproteolysis-inducing (GAIN) domain. In most aGPCRs, the GAIN domain constitutively cleaves the receptor into two fragments. This process is often required for aGPCR signalling. Over the last two decades, much research has focussed on aGPCR-ligand interactions, in an attempt to deorphanize the family. Most ligands have been found to bind to regions N-terminal to the GAIN domain. These receptors may bind a variety of ligands, ranging across membrane-bound proteins and extracellular matrix components. Recent advancements have revealed a conserved method of aGPCR activation involving a tethered ligand within the GAIN domain. Evidence for this comes from increased activity in receptor mutants exposing the tethered ligand. As a result, G protein-coupling partners of aGPCRs have been more extensively characterised, making use of their tethered ligand to create constitutively active mutants. This has led to demonstrations of aGPCR function in, for example, neurodevelopment and tumour growth. However, questions remain around the ligands that may bind many aGPCRs, how this binding is translated into changes in the GAIN domain, and the exact mechanism of aGPCR activation following GAIN domain conformational changes. This review aims to examine the current knowledge around aGPCR activation, including ligand binding sites, the mechanism of GAIN domain-mediated receptor activation and how aGPCR transmembrane domains may relate to activation. Other aspects of aGPCR signalling will be touched upon, such as downstream effectors and physiological roles.
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Affiliation(s)
- Matthew Rosa
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, U.K
| | - Timothy Noel
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, U.K
| | - Matthew Harris
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, U.K
| | - Graham Ladds
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, U.K
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5
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Abstract
Background Members of the adhesion family of G protein-coupled receptors (GPCRs) have received attention for their roles in health and disease, including cancer. Over the past decade, several members of the family have been implicated in the pathogenesis of glioblastoma. Methods Here, we discuss the basic biology of adhesion GPCRs and review in detail specific members of the receptor family with known functions in glioblastoma. Finally, we discuss the potential use of adhesion GPCRs as novel treatment targets in neuro-oncology.
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Affiliation(s)
- Gabriele Stephan
- Department of Neurosurgery, NYU Grossman School of Medicine, New York, New York, USA
| | - Niklas Ravn-Boess
- Department of Neurosurgery, NYU Grossman School of Medicine, New York, New York, USA
| | - Dimitris G Placantonakis
- Department of Neurosurgery, NYU Grossman School of Medicine, New York, New York, USA.,Kimmel Center for Stem Cell Biology, NYU Grossman School of Medicine, New York, New York, USA.,Laura and Isaac Perlmutter Cancer Center, NYU Grossman School of Medicine, New York, New York, USA.,Brain and Spine Tumor Center, NYU Grossman School of Medicine, New York, New York, USA.,Neuroscience Institute, NYU Grossman School of Medicine, New York, New York, USA
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6
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Alhaddad H, Abdi M, Lyons LA. Patterns of allele frequency differences among domestic cat breeds assessed by a 63K SNP array. PLoS One 2021; 16:e0247092. [PMID: 33630878 PMCID: PMC7906347 DOI: 10.1371/journal.pone.0247092] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 02/01/2021] [Indexed: 01/11/2023] Open
Abstract
Cats are ubiquitous companion animals that have been keenly associated with humans for thousands of years and only recently have been intentionally bred for aesthetically appealing coat looks and body forms. The intense selection on single gene phenotypes and the various breeding histories of cat breeds have left different marks on the genomes. Using a previously published 63K Feline SNP array dataset of twenty-six cat breeds, this study utilized a genetic differentiation-based method (di) to empirically identify candidate regions under selection. Defined as three or more overlapping (500Kb) windows of high levels of population differentiation, we identified a total of 205 candidate regions under selection across cat breeds with an average of 6 candidate regions per breed and an average size of 1.5 Mb per candidate region. Using the combined size of candidate regions of each breed, we conservatively estimate that a minimum of ~ 0.1-0.7% of the autosomal genome is potentially under selection in cats. As positive controls and tests of our methodology, we explored the candidate regions of known breed-defining genes (e.g., FGF5 for longhaired breeds) and we were able to detect the genes within candidate regions, each in its corresponding breed. For breed specific exploration of candidate regions under selection, eleven representative candidate regions were found to encompass potential candidate genes for several phenotypes such as brachycephaly of Persian (DLX6, DLX5, DLX2), curled ears of American Curl (MCRIP2, PBX1), and body-form of Siamese and Oriental (ADGRD1), which encourages further molecular investigations. The current assessment of the candidate regions under selection is empiric and detailed analyses are needed to rigorously disentangle effects of demography and population structure from artificial selection.
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Affiliation(s)
- Hasan Alhaddad
- Department of Biological Sciences, Kuwait University, Safat, Kuwait
| | - Mona Abdi
- Department of Biological Sciences, Kuwait University, Safat, Kuwait
| | - Leslie A. Lyons
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri - Columbia, Columbia, Missouri, United States of America
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7
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Bianchi E, Sun Y, Almansa-Ordonez A, Woods M, Goulding D, Martinez-Martin N, Wright GJ. Control of oviductal fluid flow by the G-protein coupled receptor Adgrd1 is essential for murine embryo transit. Nat Commun 2021; 12:1251. [PMID: 33623007 PMCID: PMC7902839 DOI: 10.1038/s41467-021-21512-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 01/29/2021] [Indexed: 12/16/2022] Open
Abstract
Dysfunction of embryo transport causes ectopic pregnancy which affects approximately 2% of conceptions in the US and Europe, and is the most common cause of pregnancy-related death in the first trimester. Embryo transit involves a valve-like tubal-locking phenomenon that temporarily arrests oocytes at the ampullary-isthmic junction (AIJ) where fertilisation occurs, but the mechanisms involved are unknown. Here we show that female mice lacking the orphan adhesion G-protein coupled receptor Adgrd1 are sterile because they do not relieve the AIJ restraining mechanism, inappropriately retaining embryos within the oviduct. Adgrd1 is expressed on the oviductal epithelium and the post-ovulatory attenuation of tubal fluid flow is dysregulated in Adgrd1-deficient mice. Using a large-scale extracellular protein interaction screen, we identified Plxdc2 as an activating ligand for Adgrd1 displayed on cumulus cells. Our findings demonstrate that regulating oviductal fluid flow by Adgrd1 controls embryo transit and we present a model where embryo arrest at the AIJ is due to the balance of abovarial ciliary action and the force of adovarial tubal fluid flow, and in wild-type oviducts, fluid flow is gradually attenuated through Adgrd1 activation to enable embryo release. Our findings provide important insights into the molecular mechanisms involved in embryo transport in mice. Lack of correct embryo transport can cause ectopic pregnancy. Here, the authors show that female mice lacking the adhesion G-protein coupled receptor Adgrd1 are infertile, due to embryos being trapped in the ampulla as the result of dysregulated oviductal fluid flow.
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Affiliation(s)
- Enrica Bianchi
- Cell Surface Signalling Laboratory, Wellcome Sanger Institute, Cambridge, UK
| | - Yi Sun
- Receptor Discovery Group, Microchemistry, Proteomics and Lipidomics Department, San Francisco, CA, USA.,Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | | | - Michael Woods
- Mouse Production Team, Wellcome Sanger Institute, Cambridge, UK
| | - David Goulding
- Electron and Advanced Light Microscopy Suite, Wellcome Sanger Institute, Cambridge, UK
| | - Nadia Martinez-Martin
- Receptor Discovery Group, Microchemistry, Proteomics and Lipidomics Department, San Francisco, CA, USA
| | - Gavin J Wright
- Cell Surface Signalling Laboratory, Wellcome Sanger Institute, Cambridge, UK. .,Department of Biology, Hull York Medical School, York Biomedical Research Institute, University of York, Wentworth Way, York, UK.
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8
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Schöneberg T, Liebscher I. Mutations in G Protein-Coupled Receptors: Mechanisms, Pathophysiology and Potential Therapeutic Approaches. Pharmacol Rev 2020; 73:89-119. [PMID: 33219147 DOI: 10.1124/pharmrev.120.000011] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
There are approximately 800 annotated G protein-coupled receptor (GPCR) genes, making these membrane receptors members of the most abundant gene family in the human genome. Besides being involved in manifold physiologic functions and serving as important pharmacotherapeutic targets, mutations in 55 GPCR genes cause about 66 inherited monogenic diseases in humans. Alterations of nine GPCR genes are causatively involved in inherited digenic diseases. In addition to classic gain- and loss-of-function variants, other aspects, such as biased signaling, trans-signaling, ectopic expression, allele variants of GPCRs, pseudogenes, gene fusion, and gene dosage, contribute to the repertoire of GPCR dysfunctions. However, the spectrum of alterations and GPCR involvement is probably much larger because an additional 91 GPCR genes contain homozygous or hemizygous loss-of-function mutations in human individuals with currently unidentified phenotypes. This review highlights the complexity of genomic alteration of GPCR genes as well as their functional consequences and discusses derived therapeutic approaches. SIGNIFICANCE STATEMENT: With the advent of new transgenic and sequencing technologies, the number of monogenic diseases related to G protein-coupled receptor (GPCR) mutants has significantly increased, and our understanding of the functional impact of certain kinds of mutations has substantially improved. Besides the classical gain- and loss-of-function alterations, additional aspects, such as biased signaling, trans-signaling, ectopic expression, allele variants of GPCRs, uniparental disomy, pseudogenes, gene fusion, and gene dosage, need to be elaborated in light of GPCR dysfunctions and possible therapeutic strategies.
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Affiliation(s)
- Torsten Schöneberg
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, Leipzig, Germany
| | - Ines Liebscher
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, Leipzig, Germany
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Maser RL, Calvet JP. Adhesion GPCRs as a paradigm for understanding polycystin-1 G protein regulation. Cell Signal 2020; 72:109637. [PMID: 32305667 DOI: 10.1016/j.cellsig.2020.109637] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/12/2020] [Accepted: 04/13/2020] [Indexed: 12/21/2022]
Abstract
Polycystin-1, whose mutation is the most frequent cause of autosomal dominant polycystic kidney disease, is an extremely large and multi-faceted membrane protein whose primary or proximal cyst-preventing function remains undetermined. Accumulating evidence supports the idea that modulation of cellular signaling by heterotrimeric G proteins is a critical function of polycystin-1. The presence of a cis-autocatalyzed, G protein-coupled receptor (GPCR) proteolytic cleavage site, or GPS, in its extracellular N-terminal domain immediately preceding the first transmembrane domain is one of the notable conserved features of the polycystin-1-like protein family, and also of the family of cell adhesion GPCRs. Adhesion GPCRs are one of five families within the GPCR superfamily and are distinguished by a large N-terminal extracellular region consisting of multiple adhesion modules with a GPS-containing GAIN domain and bimodal functions in cell adhesion and signal transduction. Recent advances from studies of adhesion GPCRs provide a new paradigm for unraveling the mechanisms by which polycystin-1-associated G protein signaling contributes to the pathogenesis of polycystic kidney disease. This review highlights the structural and functional features shared by polycystin-1 and the adhesion GPCRs and discusses the implications of such similarities for our further understanding of the functions of this complicated protein.
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Affiliation(s)
- Robin L Maser
- Department of Clinical Laboratory Sciences, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, Kansas 66160, USA; Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, Kansas 66160, USA; Jared Grantham Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, Kansas 66160, USA.
| | - James P Calvet
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, Kansas 66160, USA; Jared Grantham Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, Kansas 66160, USA.
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10
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Adhesion G protein-coupled receptors: opportunities for drug discovery. Nat Rev Drug Discov 2019; 18:869-884. [PMID: 31462748 DOI: 10.1038/s41573-019-0039-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2019] [Indexed: 12/24/2022]
Abstract
Adhesion G protein-coupled receptors (aGPCRs) - one of the five main families in the GPCR superfamily - have several atypical characteristics, including large, multi-domain N termini and a highly conserved region that can be autoproteolytically cleaved. Although GPCRs overall have well-established pharmacological tractability, currently no therapies that target any of the 33 members of the aGPCR family are either approved or in clinical trials. However, human genetics and preclinical research have strengthened the links between aGPCRs and disease in recent years. This, together with a greater understanding of their functional complexity, has led to growing interest in aGPCRs as drug targets. A framework for prioritizing aGPCR targets and supporting approaches to develop aGPCR modulators could therefore be valuable in harnessing the untapped therapeutic potential of this family. With this in mind, here we discuss the unique opportunities and challenges for drug discovery in modulating aGPCR functions, including target identification, target validation, assay development and safety considerations, using ADGRG1 as an illustrative example.
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Alkanfari I, Gupta K, Jahan T, Ali H. Naturally Occurring Missense MRGPRX2 Variants Display Loss of Function Phenotype for Mast Cell Degranulation in Response to Substance P, Hemokinin-1, Human β-Defensin-3, and Icatibant. THE JOURNAL OF IMMUNOLOGY 2018; 201:343-349. [PMID: 29794017 DOI: 10.4049/jimmunol.1701793] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 05/03/2018] [Indexed: 12/19/2022]
Abstract
Human mast cells (MCs) express a novel G protein-coupled receptor (GPCR) known as Mas-related GPCR X2 (MRGPRX2). Activation of this receptor by a diverse group of cationic ligands such as neuropeptides, host defense peptides, and Food and Drug Administration-approved drugs contributes to chronic inflammatory diseases and pseudoallergic drug reactions. For most GPCRs, the extracellular (ECL) domains and their associated transmembrane (TM) domains display the greatest structural diversity and are responsible for binding different ligands. The goal of the current study was to determine if naturally occurring missense variants within MRGPRX2's ECL/TM domains contribute to gain or loss of function phenotype for MC degranulation in response to neuropeptides (substance P and hemokinin-1), a host defense peptide (human β-defensin-3) and a Food and Drug Administration-approved cationic drug (bradykinin B2 receptor antagonist, icatibant). We have identified eight missense variants within MRGPRX2's ECL/TM domains from publicly available exome-sequencing databases. We investigated the ability of MRGPRX2 ligands to induce degranulation in rat basophilic leukemia-2H3 cells individually expressing these naturally occurring MRGPRX2 missense variants. Using stable and transient transfections, we found that all variants express in rat basophilic leukemia cells. However, four natural MRGPRX2 variants, G165E (rs141744602), D184H (rs372988289), W243R (rs150365137), and H259Y (rs140862085) failed to respond to any of the ligands tested. Thus, diverse MRGPRX2 ligands use common sites on the receptor to induce MC degranulation. These findings have important clinical implications for MRGPRX2 and MC-mediated pseudoallergy and chronic inflammatory diseases.
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Affiliation(s)
- Ibrahim Alkanfari
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Kshitij Gupta
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Tahsin Jahan
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Hydar Ali
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104
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12
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Abstract
Adhesion G protein-coupled receptors (aGPCRs) have a long evolutionary history dating back to very basal unicellular eukaryotes. Almost every vertebrate is equipped with a set of different aGPCRs. Genomic sequence data of several hundred extinct and extant species allows for reconstruction of aGPCR phylogeny in vertebrates and non-vertebrates in general but also provides a detailed view into the recent evolutionary history of human aGPCRs. Mining these sequence sources with bioinformatic tools can unveil many facets of formerly unappreciated aGPCR functions. In this review, we extracted such information from the literature and open public sources and provide insights into the history of aGPCR in humans. This includes comprehensive analyses of signatures of selection, variability of human aGPCR genes, and quantitative traits at human aGPCR loci. As indicated by a large number of genome-wide genotype-phenotype association studies, variations in aGPCR contribute to specific human phenotypes. Our survey demonstrates that aGPCRs are significantly involved in adaptation processes, phenotype variations, and diseases in humans.
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Affiliation(s)
- Peter Kovacs
- Integrated Research and Treatment Center (IFB) AdiposityDiseases, Medical Faculty, University of Leipzig, Liebigstr. 21, Leipzig, 04103, Germany.
| | - Torsten Schöneberg
- Institute of Biochemistry, Medical Faculty, University of Leipzig, Johannisallee 30, Leipzig, 04103, Germany.
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