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Li M, Qing R, Tao F, Xu P, Zhang S. Inhibitory effect of truncated isoforms on GPCR dimerization predicted by combinatorial computational strategy. Comput Struct Biotechnol J 2024; 23:278-286. [PMID: 38173876 PMCID: PMC10762321 DOI: 10.1016/j.csbj.2023.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 12/07/2023] [Accepted: 12/07/2023] [Indexed: 01/05/2024] Open
Abstract
G protein-coupled receptors (GPCRs) play a pivotal role in fundamental biological processes and disease development. GPCR isoforms, derived from alternative splicing, can exhibit distinct signaling patterns. Some highly-truncated isoforms can impact functional performance of full-length receptors, suggesting their intriguing regulatory roles. However, how these truncated isoforms interact with full-length counterparts remains largely unexplored. Here, we computationally investigated the interaction patterns of three human GPCRs from three different classes, ADORA1 (Class A), mGlu2 (Class C) and SMO (Class F) with their respective truncated isoforms because their homodimer structures have been experimentally determined, and they have truncated isoforms deposited and identified at protein level in Uniprot database. Combining the neural network-based AlphaFold2 and two physics-based protein-protein docking tools, we generated multiple complex structures and assessed the binding affinity in the context of atomistic molecular dynamics simulations. Our computational results suggested all the four studied truncated isoforms showed potent binding to their counterparts and overlapping interfaces with homodimers, indicating their strong potential to block homodimerization of their counterparts. Our study offers insights into functional significance of GPCR truncated isoforms and supports the ubiquity of their regulatory roles.
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Affiliation(s)
- Mengke Li
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Laboratory of Molecular Architecture, Media Lab, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Rui Qing
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Fei Tao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Shuguang Zhang
- Laboratory of Molecular Architecture, Media Lab, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
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Kuhn CK, Stenzel U, Berndt S, Liebscher I, Schöneberg T, Horn S. The repertoire and structure of adhesion GPCR transcript variants assembled from publicly available deep-sequenced human samples. Nucleic Acids Res 2024; 52:3823-3836. [PMID: 38421639 DOI: 10.1093/nar/gkae145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/24/2024] [Accepted: 02/19/2024] [Indexed: 03/02/2024] Open
Abstract
Alternative splicing and multiple transcription start and termination sites can produce a diverse repertoire of mRNA transcript variants from a given gene. While the full picture of the human transcriptome is still incomplete, publicly available RNA datasets have enabled the assembly of transcripts. Using publicly available deep sequencing data from 927 human samples across 48 tissues, we quantified known and new transcript variants, provide an interactive, browser-based application Splice-O-Mat and demonstrate its relevance using adhesion G protein-coupled receptors (aGPCRs) as an example. On average, 24 different transcript variants were detected for each of the 33 human aGPCR genes, and several dominant transcript variants were not yet annotated. Variable transcription starts and complex exon-intron structures encode a flexible protein domain architecture of the N- and C termini and the seven-transmembrane helix domain (7TMD). Notably, we discovered the first GPCR (ADGRG7/GPR128) with eight transmembrane helices. Both the N- and C terminus of this aGPCR were intracellularly oriented, anchoring the N terminus in the plasma membrane. Moreover, the assessment of tissue-specific transcript variants, also for other gene classes, in our application may change the evaluation of disease-causing mutations, as their position in different transcript variants may explain tissue-specific phenotypes.
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Affiliation(s)
- Christina Katharina Kuhn
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
| | - Udo Stenzel
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
| | - Sandra Berndt
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
| | - Ines Liebscher
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
| | - Torsten Schöneberg
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
- Department of Biochemistry, School of Medicine, University of Global Health Equity (UGHE), PO Box 6955 Kigali, Rwanda
| | - Susanne Horn
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
- Institute of Translational Genomics, Helmholtz Zentrum München - German Research Center for Environmental Health, 85764 Neuherberg, Germany
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Gao M, Dekker ME, Leurs R, Vischer HF. Pharmacological characterization of seven human histamine H 3 receptor isoforms. Eur J Pharmacol 2024; 968:176450. [PMID: 38387718 DOI: 10.1016/j.ejphar.2024.176450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/29/2024] [Accepted: 02/20/2024] [Indexed: 02/24/2024]
Abstract
The histamine H3 receptor (H3R) regulates as a presynaptic G protein-coupled receptor the release of histamine and other neurotransmitters in the brain, and is consequently a potential therapeutic target for neuronal disorders. The human H3R encodes for seven splice variants that vary in the length of intracellular loop 3 and/or the C-terminal tail but are all able to induce heterotrimeric Gi protein signaling. The last two decades H3R drug discovery and lead optimization has been exclusively focused on the 445 amino acids-long reference isoform H3R-445. In this study, we pharmacologically characterized for the first time all seven H3R isoforms by determining their binding affinities for reference histamine H3 receptor agonists and inverse agonists. The H3R-453, H3R-415, and H3R-413 isoforms display similar binding affinities for all ligands as the H3R-445. However, increased agonist binding affinities were observed for the three shorter isoforms H3R-329, H3R-365, and H3R-373, whereas inverse agonists such as the approved anti-narcolepsy drug pitolisant (Wakix®) displayed significantly decreased binding affinities for the latter two isoforms. This opposite change in binding affinity of agonist versus inverse agonists on H3R-365 and H3R-373 is associated with their higher constitutive activity in a cAMP biosensor assay as compared to the other five isoforms. The observed differences in pharmacology between longer and shorter H3R isoforms should be considered in future drug discovery programs.
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Affiliation(s)
- Meichun Gao
- Department of Medicinal Chemistry, Amsterdam Institute of Molecular Life Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands
| | - Mabel E Dekker
- Department of Medicinal Chemistry, Amsterdam Institute of Molecular Life Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands
| | - Rob Leurs
- Department of Medicinal Chemistry, Amsterdam Institute of Molecular Life Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands.
| | - Henry F Vischer
- Department of Medicinal Chemistry, Amsterdam Institute of Molecular Life Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, the Netherlands.
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Song Y, Wang ZY, Luo J, Han WC, Wang XY, Yin C, Zhao WN, Hu SW, Zhang Q, Li YQ, Cao JL. CWC22-Mediated Alternative Splicing of Spp1 Regulates Nociception in Inflammatory Pain. Neuroscience 2023; 535:50-62. [PMID: 37838283 DOI: 10.1016/j.neuroscience.2023.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 10/05/2023] [Accepted: 10/09/2023] [Indexed: 10/16/2023]
Abstract
Increasing evidence suggests that alternative splicing plays a critical role in pain, but its underlying mechanism remains elusive. Herein, we employed complete Freund's adjuvant (CFA) to induce inflammatory pain in mice. A combination of genomics research techniques, lentivirus-based genetic manipulations, behavioral tests, and molecular biological technologies confirmed that splicing factor Cwc22 mRNA and CWC22 protein were elevated in the spinal dorsal horn at 3 days after CFA injection. Knockdown of spinal CWC22 by lentivirus transfection (lenti-shCwc22) reversed CFA-induced thermal hyperalgesia and mechanical allodynia, whereas upregulation of spinal CWC22 (lenti-Cwc22) in naïve mice precipitated pain. Comprehensive transcriptome and genome analysis identified the secreted phosphoprotein 1 (Spp1) as a potential gene of CWC22-mediated alternative splicing, however, only Spp1 splicing variant 4 (Spp1 V4) was involved in thermal and mechanical nociceptive regulation. In conclusion, our findings demonstrate that spinal CWC22 regulates Spp1 V4 to participate in CFA-induced inflammatory pain. Blocking CWC22 or CWC22-mediated alternative splicing may provide a novel therapeutic target for the treatment of persistent inflammatory pain.
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Affiliation(s)
- Yu Song
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Department of Anesthesiology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu Province 221002, China
| | - Zhi-Yong Wang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Department of Anesthesiology, The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, Jiangsu Province 210008, China
| | - Jun Luo
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Department of Critical Care Medicine, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu Province 221002, China
| | - Wen-Can Han
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Xiao-Yi Wang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Department of Anesthesiology, Gulou Hospital Affiliated to Medical College of Nanjing University, Nanjing, Jiangsu Province 210008, China
| | - Cui Yin
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Wei-Nan Zhao
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Su-Wan Hu
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Qi Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Yan-Qiang Li
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China.
| | - Jun-Li Cao
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China.
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Li M, Qing R, Tao F, Xu P, Zhang S. Dynamic Dimerization of Chemokine Receptors and Potential Inhibitory Role of Their Truncated Isoforms Revealed through Combinatorial Prediction. Int J Mol Sci 2023; 24:16266. [PMID: 38003455 PMCID: PMC10671024 DOI: 10.3390/ijms242216266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 11/03/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Chemokine receptors play crucial roles in fundamental biological processes. Their malfunction may result in many diseases, including cancer, autoimmune diseases, and HIV. The oligomerization of chemokine receptors holds significant functional implications that directly affect their signaling patterns and pharmacological responses. However, the oligomerization patterns of many chemokine receptors remain poorly understood. Furthermore, several chemokine receptors have highly truncated isoforms whose functional role is not yet clear. Here, we computationally show homo- and heterodimerization patterns of four human chemokine receptors, namely CXCR2, CXCR7, CCR2, and CCR7, along with their interaction patterns with their respective truncated isoforms. By combining the neural network-based AlphaFold2 and physics-based protein-protein docking tool ClusPro, we predicted 15 groups of complex structures and assessed the binding affinities in the context of atomistic molecular dynamics simulations. Our results are in agreement with previous experimental observations and support the dynamic and diverse nature of chemokine receptor dimerization, suggesting possible patterns of higher-order oligomerization. Additionally, we uncover the strong potential of truncated isoforms to block homo- and heterodimerization of chemokine receptors, also in a dynamic manner. Our study provides insights into the dimerization patterns of chemokine receptors and the functional significance of their truncated isoforms.
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Affiliation(s)
- Mengke Li
- Laboratory of Molecular Architecture, Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139, USA;
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (R.Q.); (F.T.); (P.X.)
| | - Rui Qing
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (R.Q.); (F.T.); (P.X.)
| | - Fei Tao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (R.Q.); (F.T.); (P.X.)
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China; (R.Q.); (F.T.); (P.X.)
| | - Shuguang Zhang
- Laboratory of Molecular Architecture, Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139, USA;
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Zhao F, Hang K, Zhou Q, Shao L, Li H, Li W, Lin S, Dai A, Cai X, Liu Y, Xu Y, Feng W, Yang D, Wang MW. Molecular basis of signal transduction mediated by the human GIPR splice variants. Proc Natl Acad Sci U S A 2023; 120:e2306145120. [PMID: 37792509 PMCID: PMC10576055 DOI: 10.1073/pnas.2306145120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 08/07/2023] [Indexed: 10/06/2023] Open
Abstract
Glucose-dependent insulinotropic polypeptide receptor (GIPR) is a potential drug target for metabolic disorders. It works with glucagon-like peptide-1 receptor and glucagon receptor in humans to maintain glucose homeostasis. Unlike the other two receptors, GIPR has at least 13 reported splice variants (SVs), more than half of which have sequence variations at either C or N terminus. To explore their roles in endogenous peptide-mediated GIPR signaling, we determined the cryoelectron microscopy (cryo-EM) structures of the two N terminus-altered SVs (referred as GIPR-202 and GIPR-209 in the Ensembl database, SV1 and SV2 here, respectively) and investigated the outcome of coexpressing each of them in question with GIPR in HEK293T cells with respect to ligand binding, receptor expression, cAMP (adenosine 3,5-cyclic monophosphate) accumulation, β-arrestin recruitment, and cell surface localization. It was found that while both N terminus-altered SVs of GIPR neither bound to the hormone nor elicited signal transduction per se, they suppressed ligand binding and cAMP accumulation of GIPR. Meanwhile, SV1 reduced GIPR-mediated β-arrestin 2 responses. The cryo-EM structures of SV1 and SV2 showed that they reorganized the extracellular halves of transmembrane helices 1, 6, and 7 and extracellular loops 2 and 3 to adopt a ligand-binding pocket-occupied conformation, thereby losing binding ability to the peptide. The results suggest a form of signal bias that is constitutive and ligand-independent, thus expanding our knowledge of biased signaling beyond pharmacological manipulation (i.e., ligand specific) as well as constitutive and ligand-independent (e.g., SV1 of the growth hormone-releasing hormone receptor).
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Affiliation(s)
- Fenghui Zhao
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
| | - Kaini Hang
- iHuman Institute, ShanghaiTech University, Shanghai201210, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai201210, China
| | - Qingtong Zhou
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai200032, China
- Research Center for Deepsea Bioresources, Sanya, Hainan572025, China
| | - Lijun Shao
- iHuman Institute, ShanghaiTech University, Shanghai201210, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai201210, China
| | - Hao Li
- Research Center for Deepsea Bioresources, Sanya, Hainan572025, China
| | - Wenzhuo Li
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
| | - Shi Lin
- Research Center for Deepsea Bioresources, Sanya, Hainan572025, China
| | - Antao Dai
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
| | - Xiaoqing Cai
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
| | - Yanyun Liu
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing210023, China
| | - Yingna Xu
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai200032, China
| | - Wenbo Feng
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai200032, China
| | - Dehua Yang
- The National Center for Drug Screening, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai201203, China
- Research Center for Deepsea Bioresources, Sanya, Hainan572025, China
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing210023, China
| | - Ming-Wei Wang
- Department of Pharmacology, School of Basic Medical Sciences, Fudan University, Shanghai200032, China
- Research Center for Deepsea Bioresources, Sanya, Hainan572025, China
- Department of Chemistry, School of Science, The University of Tokyo, Tokyo113-0033, Japan
- School of Pharmacy, Hainan Medical University, Haikou570228, China
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Kim MA, Kim TH, Kannan P, Kho KH, Park K, Sohn YC. Functional Characterization of Gonadotropin-Releasing Hormone and Corazonin Signaling Systems in Pacific Abalone: Toward Reclassification of Invertebrate Neuropeptides. Neuroendocrinology 2023; 114:64-89. [PMID: 37703838 DOI: 10.1159/000533662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 08/14/2023] [Indexed: 09/15/2023]
Abstract
INTRODUCTION The proposed evolutionary origins and corresponding nomenclature of bilaterian gonadotropin-releasing hormone (GnRH)-related neuropeptides have changed tremendously with the aid of receptor deorphanization. However, the reclassification of the GnRH and corazonin (CRZ) signaling systems in Lophotrochozoa remains unclear. METHODS We characterized GnRH and CRZ receptors in the mollusk Pacific abalone, Haliotis discus hannai (Hdh), by phylogenetic and gene expression analyses, bioluminescence-based reporter, Western blotting, substitution of peptide amino acids, in vivo neuropeptide injection, and RNA interference assays. RESULTS Two Hdh CRZ-like receptors (Hdh-CRZR-A and Hdh-CRZR-B) and three Hdh GnRH-like receptors (Hdh-GnRHR1-A, Hdh-GnRHR1-B, and Hdh-GnRHR2) were identified. In phylogenetic analysis, Hdh-CRZR-A and -B grouped within the CRZ-type receptors, whereas Hdh-GnRHR1-A/-B and Hdh-GnRHR2 clustered within the GnRH/adipokinetic hormone (AKH)/CRZ-related peptide-type receptors. Hdh-CRZR-A/-B and Hdh-GnRHR1-A were activated by Hdh-CRZ (pQNYHFSNGWHA-NH2) and Hdh-GnRH (pQISFSPNWGT-NH2), respectively. Hdh-CRZR-A/-B dually coupled with the Gαq and Gαs signaling pathways, whereas Hdh-GnRHR1-A was linked only with Gαq signaling. Analysis of substituted peptides, [I2S3]Hdh-CRZ and [N2Y3H4]Hdh-GnRH, and in silico docking models revealed that the N-terminal amino acids of the peptides are critical for the selectivity of Hdh-CRZR and Hdh-GnRHR. Two precursor transcripts for Hdh-CRZ and Hdh-GnRH peptides and their receptors were mainly expressed in the neural ganglia, and their levels increased in starved abalones. Injection of Hdh-CRZ peptide into abalones decreased food consumption, whereas Hdh-CRZR knockdown increased food consumption. Moreover, Hdh-CRZ induced germinal vesicle breakdown in mature oocytes. CONCLUSION Characterization of Hdh-CRZRs and Hdh-GnRHRs and their cognate peptides provides new insight into the evolutionary route of GnRH-related signaling systems in bilaterians.
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Affiliation(s)
- Mi Ae Kim
- Department of Marine Bioscience, Gangneung-Wonju National University, Gangneung, Republic of Korea
- East Coast Life Sciences Institute, Gangneung-Wonju National University, Gangneung, Republic of Korea
| | - Tae Ha Kim
- Department of Marine Bioscience, Gangneung-Wonju National University, Gangneung, Republic of Korea
| | - Priyadharshini Kannan
- Natural Product Informatics Research Center, KIST Gangneung Institute of Natural Products, Gangneung, Republic of Korea
- Department of Biochemical Engineering, Gangneung-Wonju National University, Gangneung, Republic of Korea
| | - Kang Hee Kho
- Department of Fisheries Science, Chonnam National University, Yeosu, Republic of Korea
| | - Keunwan Park
- Natural Product Informatics Research Center, KIST Gangneung Institute of Natural Products, Gangneung, Republic of Korea
| | - Young Chang Sohn
- Department of Marine Bioscience, Gangneung-Wonju National University, Gangneung, Republic of Korea
- East Coast Life Sciences Institute, Gangneung-Wonju National University, Gangneung, Republic of Korea
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Danoff JS, Page EA, Perkeybile AM, Kenkel WM, Yee JR, Ferris CF, Carter CS, Connelly JJ. Transcriptional diversity of the oxytocin receptor in prairie voles: mechanistic implications for behavioral neuroscience and maternal physiology. Front Genet 2023; 14:1225197. [PMID: 37705612 PMCID: PMC10495980 DOI: 10.3389/fgene.2023.1225197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 08/14/2023] [Indexed: 09/15/2023] Open
Abstract
The neurohormone oxytocin regulates many aspects of physiology primarily by binding to its receptor, the oxytocin receptor. The oxytocin receptor gene (Oxtr) has been shown to have alternative transcripts in the mouse brain which may each have different biological functions or be used in specific contexts. A popular animal model for studying oxytocin-dependent social behaviors is the prairie vole, a biparental and monogamous rodent. Alternative transcriptional capacity of Oxtr in prairie voles is unknown. We used 5' rapid amplification of cDNA ends to identify alternative Oxtr transcription start sites in prairie vole brain tissue and uterine tissue. We then validated expression of specific transcripts in fetal brains and assessed the impact of exogenous oxytocin administration in utero on offspring brain development. We identified seven distinct Oxtr transcripts, all of which are present in both brain and uterine tissue. We then demonstrated that maternal oxytocin administration alters expression of a specific subset of Oxtr transcripts and that these different transcripts are under unique epigenetic regulation, such that in the perinatal period only one of the alternative transcripts is associated with DNA methylation in the Oxtr promoter. These data establish the existence of multiple Oxtr transcripts in prairie vole brain and uterine tissue and implicate oxytocin in the regulation of alternative transcript expression. These data have significant implications for our understanding of null mutant models in both mice and voles and translation in human birth and behavior.
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Affiliation(s)
- Joshua S. Danoff
- Department of Psychology, University of Virginia, Charlottesville, VA, United States
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, United States
| | - Emma A. Page
- Department of Psychology, University of Virginia, Charlottesville, VA, United States
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, United States
| | - Allison M. Perkeybile
- Department of Psychology, University of Virginia, Charlottesville, VA, United States
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, United States
| | - William M. Kenkel
- Department of Psychological and Brain Sciences, University of Delaware, Newark, DE, United States
| | - Jason R. Yee
- Institute of Animal Welfare Science, University of Veterinary Medicine, Vienna, WIE, Austria
| | - Craig F. Ferris
- Department of Psychology, Center for Translational Neuroimaging, Northeastern University, Boston, MA, United States
| | - C. Sue Carter
- Department of Psychology, University of Virginia, Charlottesville, VA, United States
| | - Jessica J. Connelly
- Department of Psychology, University of Virginia, Charlottesville, VA, United States
- Program in Fundamental Neuroscience, University of Virginia, Charlottesville, VA, United States
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Pederick DT, Perry-Hauser NA, Meng H, He Z, Javitch JA, Luo L. Context-dependent requirement of G protein coupling for Latrophilin-2 in target selection of hippocampal axons. eLife 2023; 12:e83529. [PMID: 36939320 PMCID: PMC10118387 DOI: 10.7554/elife.83529] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 03/16/2023] [Indexed: 03/21/2023] Open
Abstract
The formation of neural circuits requires extensive interactions of cell-surface proteins to guide axons to their correct target neurons. Trans-cellular interactions of the adhesion G protein-coupled receptor latrophilin-2 (Lphn2) with its partner teneurin-3 instruct the precise assembly of hippocampal networks by reciprocal repulsion. Lphn2 acts as a repulsive receptor in distal CA1 neurons to direct their axons to the proximal subiculum, and as a repulsive ligand in the proximal subiculum to direct proximal CA1 axons to the distal subiculum. It remains unclear if Lphn2-mediated intracellular signaling is required for its role in either context. Here, we show that Lphn2 couples to Gα12/13 in heterologous cells; this coupling is increased by constitutive exposure of the tethered agonist. Specific mutations of Lphn2's tethered agonist region disrupt its G protein coupling and autoproteolytic cleavage, whereas mutating the autoproteolytic cleavage site alone prevents cleavage but preserves a functional tethered agonist. Using an in vivo misexpression assay, we demonstrate that wild-type Lphn2 misdirects proximal CA1 axons to the proximal subiculum and that Lphn2 tethered agonist activity is required for its role as a repulsive receptor in axons. By contrast, neither tethered agonist activity nor autoproteolysis were necessary for Lphn2's role as a repulsive ligand in the subiculum target neurons. Thus, tethered agonist activity is required for Lphn2-mediated neural circuit assembly in a context-dependent manner.
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Affiliation(s)
- Daniel T Pederick
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Nicole A Perry-Hauser
- Departments of Psychiatry and Molecular Pharmacology and Therapeutics, Columbia University Vagelos College of Physicians and SurgeonsNew YorkUnited States
- Division of Molecular Therapeutics, New York State Psychiatric InstituteNew YorkUnited States
| | - Huyan Meng
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical SchoolBostonUnited States
| | - Zhigang He
- F.M. Kirby Neurobiology Center, Department of Neurology, Boston Children’s Hospital, Harvard Medical SchoolBostonUnited States
| | - Jonathan A Javitch
- Departments of Psychiatry and Molecular Pharmacology and Therapeutics, Columbia University Vagelos College of Physicians and SurgeonsNew YorkUnited States
- Division of Molecular Therapeutics, New York State Psychiatric InstituteNew YorkUnited States
| | - Liqun Luo
- Department of Biology, Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
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10
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Shaw TI, Zhao B, Li Y, Wang H, Wang L, Manley B, Stewart PA, Karolak A. Multi-omics approach to identifying isoform variants as therapeutic targets in cancer patients. Front Oncol 2022; 12:1051487. [PMID: 36505834 PMCID: PMC9730332 DOI: 10.3389/fonc.2022.1051487] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 11/07/2022] [Indexed: 11/25/2022] Open
Abstract
Cancer-specific alternatively spliced events (ASE) play a role in cancer pathogenesis and can be targeted by immunotherapy, oligonucleotide therapy, and small molecule inhibition. However, identifying actionable ASE targets remains challenging due to the uncertainty of its protein product, structure impact, and proteoform (protein isoform) function. Here we argue that an integrated multi-omics profiling strategy can overcome these challenges, allowing us to mine this untapped source of targets for therapeutic development. In this review, we will provide an overview of current multi-omics strategies in characterizing ASEs by utilizing the transcriptome, proteome, and state-of-art algorithms for protein structure prediction. We will discuss limitations and knowledge gaps associated with each technology and informatics analytics. Finally, we will discuss future directions that will enable the full integration of multi-omics data for ASE target discovery.
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Affiliation(s)
- Timothy I. Shaw
- Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, United States,*Correspondence: Timothy I. Shaw,
| | - Bi Zhao
- Department of Machine Learning, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, United States
| | - Yuxin Li
- Center for Proteomics and Metabolomics, St. Jude Children’s Research Hospital, Memphis, TN, United States
| | - Hong Wang
- Center for Proteomics and Metabolomics, St. Jude Children’s Research Hospital, Memphis, TN, United States
| | - Liang Wang
- Department of Tumor Biology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, United States
| | - Brandon Manley
- Department of Genitourinary Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, United States
| | - Paul A. Stewart
- Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, United States
| | - Aleksandra Karolak
- Department of Machine Learning, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, United States
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11
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Tasma Z, Siow A, Harris PWR, Brimble MA, O’Carroll SJ, Hay DL, Walker CS. PAC 1, VPAC 1, and VPAC 2 Receptor Expression in Rat and Human Trigeminal Ganglia: Characterization of PACAP-Responsive Receptor Antibodies. Int J Mol Sci 2022; 23:ijms232213797. [PMID: 36430275 PMCID: PMC9697343 DOI: 10.3390/ijms232213797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/02/2022] [Accepted: 11/06/2022] [Indexed: 11/11/2022] Open
Abstract
Pituitary adenylate cyclase-activating peptide (PACAP) is a neuropeptide expressed in the trigeminal ganglia (TG). The TG conducts nociceptive signals in the head and may play roles in migraine. PACAP infusion provokes headaches in healthy individuals and migraine-like attacks in patients; however, it is not clear whether targeting this system could be therapeutically efficacious. To effectively target the PACAP system, an understanding of PACAP receptor distribution is required. Therefore, this study aimed to characterize commercially available antibodies and use these to detect PACAP-responsive receptors in the TG. Antibodies were initially validated in receptor transfected cell models and then used to explore receptor expression in rat and human TG. Antibodies were identified that could detect PACAP-responsive receptors, including the first antibody to differentiate between the PAC1n and PAC1s receptor splice variants. PAC1, VPAC1, and VPAC2 receptor-like immunoreactivity were observed in subpopulations of both neuronal and glial-like cells in the TG. In this study, PAC1, VPAC1, and VPAC2 receptors were detected in the TG, suggesting they are all potential targets to treat migraine. These antibodies may be useful tools to help elucidate PACAP-responsive receptor expression in tissues. However, most antibodies exhibited limitations, requiring the use of multiple methodologies and the careful inclusion of controls.
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Affiliation(s)
- Zoe Tasma
- School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand
| | - Andrew Siow
- School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
| | - Paul W. R. Harris
- School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
| | - Margaret A. Brimble
- School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
| | - Simon J. O’Carroll
- Department of Anatomy and Medical Imaging, and Centre for Brain Research, Faculty of Medical and Health Science, The University of Auckland, Auckland 1023, New Zealand
| | - Debbie L. Hay
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
- Department of Pharmacology and Toxicology, The University of Otago, Dunedin 9016, New Zealand
| | - Christopher S. Walker
- School of Biological Sciences, The University of Auckland, Auckland 1010, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland 1010, New Zealand
- Correspondence:
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12
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Schihada H, Klompstra TM, Humphrys LJ, Cervenka I, Dadvar S, Kolb P, Ruas JL, Schulte G. Isoforms of GPR35 have distinct extracellular N-termini that allosterically modify receptor-transducer coupling and mediate intracellular pathway bias. J Biol Chem 2022; 298:102328. [PMID: 35933013 PMCID: PMC9450150 DOI: 10.1016/j.jbc.2022.102328] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 11/29/2022] Open
Abstract
Within the intestine, the human G protein–coupled receptor (GPCR) GPR35 is involved in oncogenic signaling, bacterial infections, and inflammatory bowel disease. GPR35 is known to be expressed as two distinct isoforms that differ only in the length of their extracellular N-termini by 31 amino acids, but detailed insights into their functional differences are lacking. Through gene expression analysis in immune and gastrointestinal cells, we show that these isoforms emerge from distinct promoter usage and alternative splicing. Additionally, we employed optical assays in living cells to thoroughly profile both GPR35 isoforms for constitutive and ligand-induced activation and signaling of 10 different heterotrimeric G proteins, ligand-induced arrestin recruitment, and receptor internalization. Our results reveal that the extended N-terminus of the long isoform limits G protein activation yet elevates receptor–β-arrestin interaction. To better understand the structural basis for this bias, we examined structural models of GPR35 and conducted experiments with mutants of both isoforms. We found that a proposed disulfide bridge between the N-terminus and extracellular loop 3, present in both isoforms, is crucial for constitutive G13 activation, while an additional cysteine contributed by the extended N-terminus of the long GPR35 isoform limits the extent of agonist-induced receptor–β-arrestin2 interaction. The pharmacological profiles and mechanistic insights of our study provide clues for the future design of isoform-specific GPR35 ligands that selectively modulate GPR35–transducer interactions and allow for mechanism-based therapies against, for example, inflammatory bowel disease or bacterial infections of the gastrointestinal system.
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Affiliation(s)
- Hannes Schihada
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; Department of Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany.
| | - Thomas M Klompstra
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Laura J Humphrys
- Institute of Pharmacy, University of Regensburg, Regensburg, Germany
| | - Igor Cervenka
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Shamim Dadvar
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Peter Kolb
- Department of Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Jorge L Ruas
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Gunnar Schulte
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
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13
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Li J, Remington JM, Liao C, Parsons RL, Schneebeli S, Braas KM, May V, Brewer M. GPCR Intracellular Loop Regulation of Beta-Arrestin-Mediated Endosomal Signaling Dynamics. J Mol Neurosci 2022; 72:1358-1373. [PMID: 35538393 PMCID: PMC9311399 DOI: 10.1007/s12031-022-02016-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 04/22/2022] [Indexed: 12/22/2022]
Abstract
G protein-coupled receptors (GPCRs) are currently appreciated to be routed to diverse cellular platforms to generate both G protein-dependent and -independent signals. The latter has been best studied with respect to β-arrestin-associated receptor internalization and trafficking to signaling endosomes for extracellular signal-regulated kinase (ERK) activation. However, how GPCR structural and conformational variants regulate endosomal ERK signaling dynamics, which can be central in neural development, plasticity, and disease processes, is not well understood. Among class B GPCRs, the PACAP-selective PAC1 receptor is unique in the expression of variants that can contain intracellular loop 3 (ICL3) cassette inserts. The nervous system expresses preferentially the PAC1Null (no insert) and PAC1Hop (28-amino acid Hop insert) receptor variants. Our molecular modeling and signaling studies revealed that the PAC1Null and PAC1Hop receptor variants can associate with β-arrestin differentially, resulting in enhanced receptor internalization and ERK activation for the PAC1Hop variant. The study amplifies our understandings of GPCR intracellular loop structure/function relationships with the first example of how the duration of endosomal ERK activation can be guided by ICL3. The results provide a framework for how changes in GPCR variant expression can impact developmental and homeostatic processes and may be contributory to maladaptive neuroplasticity underlying chronic pain and stress-related disorders.
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Affiliation(s)
- Jianing Li
- Department of Chemistry, University of Vermont, 82 University Place, Burlington, VT, 05405, USA.
| | - Jacob M Remington
- Department of Chemistry, University of Vermont, 82 University Place, Burlington, VT, 05405, USA
| | - Chenyi Liao
- Department of Chemistry, University of Vermont, 82 University Place, Burlington, VT, 05405, USA
| | - Rodney L Parsons
- Department of Neurological Sciences, University of Vermont College of Medicine, 149 Beaumont Avenue, Burlington, VT, 05405, USA
| | - Severin Schneebeli
- Department of Chemistry, University of Vermont, 82 University Place, Burlington, VT, 05405, USA
| | - Karen M Braas
- Department of Neurological Sciences, University of Vermont College of Medicine, 149 Beaumont Avenue, Burlington, VT, 05405, USA
| | - Victor May
- Department of Neurological Sciences, University of Vermont College of Medicine, 149 Beaumont Avenue, Burlington, VT, 05405, USA.
| | - Matthias Brewer
- Department of Chemistry, University of Vermont, 82 University Place, Burlington, VT, 05405, USA
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14
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Liu S, Kang WJ, Abrimian A, Xu J, Cartegni L, Majumdar S, Hesketh P, Bekker A, Pan YX. Alternative Pre-mRNA Splicing of the Mu Opioid Receptor Gene, OPRM1: Insight into Complex Mu Opioid Actions. Biomolecules 2021; 11:biom11101525. [PMID: 34680158 PMCID: PMC8534031 DOI: 10.3390/biom11101525] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/11/2021] [Accepted: 10/11/2021] [Indexed: 12/03/2022] Open
Abstract
Most opioid analgesics used clinically, including morphine and fentanyl, as well as the recreational drug heroin, act primarily through the mu opioid receptor, a class A Rhodopsin-like G protein-coupled receptor (GPCR). The single-copy mu opioid receptor gene, OPRM1, undergoes extensive alternative splicing, creating multiple splice variants or isoforms via a variety of alternative splicing events. These OPRM1 splice variants can be categorized into three major types based on the receptor structure: (1) full-length 7 transmembrane (TM) C-terminal variants; (2) truncated 6TM variants; and (3) single TM variants. Increasing evidence suggests that these OPRM1 splice variants are pharmacologically important in mediating the distinct actions of various mu opioids. More importantly, the OPRM1 variants can be targeted for development of novel opioid analgesics that are potent against multiple types of pain, but devoid of many side-effects associated with traditional opiates. In this review, we provide an overview of OPRM1 alternative splicing and its functional relevance in opioid pharmacology.
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Affiliation(s)
- Shan Liu
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; (S.L.); (W.-J.K.); (A.A.); (J.X.); (P.H.); (A.B.)
| | - Wen-Jia Kang
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; (S.L.); (W.-J.K.); (A.A.); (J.X.); (P.H.); (A.B.)
| | - Anna Abrimian
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; (S.L.); (W.-J.K.); (A.A.); (J.X.); (P.H.); (A.B.)
| | - Jin Xu
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; (S.L.); (W.-J.K.); (A.A.); (J.X.); (P.H.); (A.B.)
| | - Luca Cartegni
- Department of Chemical Biology, Ernest Mario School of Pharmacy Rutgers University, Piscataway, NJ 08854, USA;
| | - Susruta Majumdar
- Center for Clinical Pharmacology, University of Health Sciences & Pharmacy and Washington University School of Medicine, St. Louis, MO 63110, USA;
| | - Patrick Hesketh
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; (S.L.); (W.-J.K.); (A.A.); (J.X.); (P.H.); (A.B.)
| | - Alex Bekker
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; (S.L.); (W.-J.K.); (A.A.); (J.X.); (P.H.); (A.B.)
| | - Ying-Xian Pan
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; (S.L.); (W.-J.K.); (A.A.); (J.X.); (P.H.); (A.B.)
- Correspondence: ; Tel.: +1-973-972-3213
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15
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Tasma Z, Siow A, Harris PWR, Brimble MA, Hay DL, Walker CS. Characterisation of agonist signalling profiles and agonist-dependent antagonism at PACAP-responsive receptors: Implications for drug discovery. Br J Pharmacol 2021; 179:435-453. [PMID: 34612509 DOI: 10.1111/bph.15700] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 08/16/2021] [Accepted: 08/30/2021] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND AND PURPOSE The pituitary adenylate cyclase-activating peptide (PACAP) family is of clinical interest for the treatment of migraine. These peptides activate three different PACAP-responsive class B G protein-coupled receptors: the PAC1 , VPAC1 and VPAC2 receptors. The PAC1 receptor may be alternatively spliced, generating variants that can differ in their pharmacological or signalling profiles. To inform drug discovery efforts targeting migraine, we need to better understand how the different PACAP-responsive receptors signal and how effectively these responses can be blocked by antagonists. EXPERIMENTAL APPROACH The signalling profiles of the human PAC1n , PAC1s , VPAC1 and VPAC2 receptors were examined in transfected Cos7 cells for cAMP, IP1 , pAkt, pERK and pCREB. Biased signalling was then quantified. The ability of antagonists to block PACAP-38, PACAP-27 or VIP stimulated cAMP accumulation at PACAP-responsive receptors was also determined. KEY RESULTS PACAP-responsive receptors exhibited varied pharmacological profiles but activated signalling in a similar manner. The PAC1n and PAC1s receptors displayed distinct pharmacology. At the PAC1s receptor, VIP and PHM were more potent than at the PAC1n receptor. PACAP-responsive receptors displayed agonist-dependent antagonism where PACAP-38 was less effectively antagonised compared to PACAP-27 and VIP. CONCLUSIONS AND IMPLICATIONS The distinct pharmacological profile displayed by the PAC1s receptor suggests that it can act as a dual receptor for VIP and PACAP. Furthermore, the effectiveness of blocking a signalling pathway can be influenced by which endogenous PACAP family agonist is present. These effects have potential implications for the development and effectiveness of drugs targeting the PACAP system.
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Affiliation(s)
- Zoe Tasma
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Andrew Siow
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,School of Chemical Sciences, University of Auckland, Auckland, New Zealand
| | - Paul W R Harris
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,School of Chemical Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre and Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Margaret A Brimble
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,School of Chemical Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre and Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
| | - Debbie L Hay
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre and Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand.,Department of Pharmacology and Toxicology, University of Otago, Dunedin, New Zealand
| | - Christopher S Walker
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Maurice Wilkins Centre and Centre for Molecular Biodiscovery, University of Auckland, Auckland, New Zealand
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16
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Constitutive signal bias mediated by the human GHRHR splice variant 1. Proc Natl Acad Sci U S A 2021; 118:2106606118. [PMID: 34599099 PMCID: PMC8501799 DOI: 10.1073/pnas.2106606118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/17/2021] [Indexed: 11/18/2022] Open
Abstract
The mechanism of functional changes induced by alternative splicing of GHRHR is largely unknown. Here, we demonstrate that GHRH-elicited signal bias toward β-arrestin recruitment is constitutively mediated by SV1. The cryogenic electron microscopy structures of SV1 and molecular dynamics simulations reveal the different functionalities between GHRHR and SV1 at the near-atomic level (i.e., the N termini of GHRHR and SV1 differentiate the downstream signaling pathways, Gs versus β-arrestins). Our findings provide valuable insights into the functional diversity of class B1 GPCRs that may aid in the design of better therapeutic agents against certain cancers. Alternative splicing of G protein–coupled receptors has been observed, but their functions are largely unknown. Here, we report that a splice variant (SV1) of the human growth hormone–releasing hormone receptor (GHRHR) is capable of transducing biased signal. Differing only at the receptor N terminus, GHRHR predominantly activates Gs while SV1 selectively couples to β-arrestins. Based on the cryogenic electron microscopy structures of SV1 in the apo state or GHRH-bound state in complex with the Gs protein, molecular dynamics simulations reveal that the N termini of GHRHR and SV1 differentiate the downstream signaling pathways, Gs versus β-arrestins. As suggested by mutagenesis and functional studies, it appears that GHRH-elicited signal bias toward β-arrestin recruitment is constitutively mediated by SV1. The level of SV1 expression in prostate cancer cells is also positively correlated with ERK1/2 phosphorylation but negatively correlated with cAMP response. Our findings imply that constitutive signal bias may be a mechanism that ensures cancer cell proliferation.
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17
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Soave M, Stoddart LA, White CW, Kilpatrick LE, Goulding J, Briddon SJ, Hill SJ. Detection of genome-edited and endogenously expressed G protein-coupled receptors. FEBS J 2021; 288:2585-2601. [PMID: 33506623 PMCID: PMC8647918 DOI: 10.1111/febs.15729] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/20/2021] [Accepted: 01/25/2021] [Indexed: 12/11/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of membrane receptors and major targets for FDA-approved drugs. The ability to quantify GPCR expression and ligand binding characteristics in different cell types and tissues is therefore important for drug discovery. The advent of genome editing along with developments in fluorescent ligand design offers exciting new possibilities to probe GPCRs in their native environment. This review provides an overview of the recent technical advances employed to study the localisation and ligand binding characteristics of genome-edited and endogenously expressed GPCRs.
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Affiliation(s)
- Mark Soave
- Division of Physiology, Pharmacology and NeuroscienceSchool of Life SciencesUniversity of NottinghamUK
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
| | - Leigh A. Stoddart
- Division of Physiology, Pharmacology and NeuroscienceSchool of Life SciencesUniversity of NottinghamUK
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
| | - Carl W. White
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
- Harry Perkins Institute of Medical Research and Centre for Medical ResearchQEII Medical CentreThe University of Western AustraliaNedlandsAustralia
- Australian Research Council Centre for Personalised Therapeutics TechnologiesAustralia
| | - Laura E. Kilpatrick
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
- Division of Biomolecular Science and Medicinal ChemistrySchool of Pharmacy, Biodiscovery InstituteUniversity of NottinghamUK
| | - Joëlle Goulding
- Division of Physiology, Pharmacology and NeuroscienceSchool of Life SciencesUniversity of NottinghamUK
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
| | - Stephen J. Briddon
- Division of Physiology, Pharmacology and NeuroscienceSchool of Life SciencesUniversity of NottinghamUK
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
| | - Stephen J. Hill
- Division of Physiology, Pharmacology and NeuroscienceSchool of Life SciencesUniversity of NottinghamUK
- Centre of Membrane Proteins and Receptors (COMPARE)University of Birmingham and University of NottinghamThe MidlandsUK
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18
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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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19
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Marti-Solano M, Crilly SE, Malinverni D, Munk C, Harris M, Pearce A, Quon T, Mackenzie AE, Wang X, Peng J, Tobin AB, Ladds G, Milligan G, Gloriam DE, Puthenveedu MA, Babu MM. Combinatorial expression of GPCR isoforms affects signalling and drug responses. Nature 2020; 587:650-656. [PMID: 33149304 PMCID: PMC7611127 DOI: 10.1038/s41586-020-2888-2] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 09/24/2020] [Indexed: 02/06/2023]
Abstract
G-protein-coupled receptors (GPCRs) are membrane proteins that modulate physiology across human tissues in response to extracellular signals. GPCR-mediated signalling can differ because of changes in the sequence1,2 or expression3 of the receptors, leading to signalling bias when comparing diverse physiological systems4. An underexplored source of such bias is the generation of functionally diverse GPCR isoforms with different patterns of expression across different tissues. Here we integrate data from human tissue-level transcriptomes, GPCR sequences and structures, proteomics, single-cell transcriptomics, population-wide genetic association studies and pharmacological experiments. We show how a single GPCR gene can diversify into several isoforms with distinct signalling properties, and how unique isoform combinations expressed in different tissues can generate distinct signalling states. Depending on their structural changes and expression patterns, some of the detected isoforms may influence cellular responses to drugs and represent new targets for developing drugs with improved tissue selectivity. Our findings highlight the need to move from a canonical to a context-specific view of GPCR signalling that considers how combinatorial expression of isoforms in a particular cell type, tissue or organism collectively influences receptor signalling and drug responses.
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Affiliation(s)
| | - Stephanie E Crilly
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
| | - Duccio Malinverni
- MRC Laboratory of Molecular Biology, Cambridge, UK
- Department of Structural Biology and Center for Data Driven Discovery, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Christian Munk
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Matthew Harris
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Abigail Pearce
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Tezz Quon
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Amanda E Mackenzie
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Xusheng Wang
- Center for Proteomics and Metabolomics, St Jude Children's Research Hospital, Memphis, TN, USA
- Department of Biology, University of North Dakota, Grand Forks, ND, USA
| | - Junmin Peng
- Center for Proteomics and Metabolomics, St Jude Children's Research Hospital, Memphis, TN, USA
- Departments of Structural Biology and Developmental Neurobiology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Andrew B Tobin
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Graham Ladds
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Graeme Milligan
- Centre for Translational Pharmacology, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - David E Gloriam
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Manojkumar A Puthenveedu
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - M Madan Babu
- MRC Laboratory of Molecular Biology, Cambridge, UK.
- Department of Structural Biology and Center for Data Driven Discovery, St Jude Children's Research Hospital, Memphis, TN, USA.
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Conversion of extracellular ATP into adenosine: a master switch in renal health and disease. Nat Rev Nephrol 2020; 16:509-524. [PMID: 32641760 DOI: 10.1038/s41581-020-0304-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/01/2020] [Indexed: 12/22/2022]
Abstract
ATP and its ultimate degradation product adenosine are potent extracellular signalling molecules that elicit a variety of pathophysiological functions in the kidney through the activation of P2 and P1 purinergic receptors, respectively. Extracellular purines can modulate immune responses, balancing inflammatory processes and immunosuppression; indeed, alterations in extracellular nucleotide and adenosine signalling determine outcomes of inflammation and healing processes. The functional activities of ectonucleotidases such as CD39 and CD73, which hydrolyse pro-inflammatory ATP to generate immunosuppressive adenosine, are therefore pivotal in acute inflammation. Protracted inflammation may result in aberrant adenosinergic signalling, which serves to sustain inflammasome activation and worsen fibrotic reactions. Alterations in the expression of ectonucleotidases on various immune cells, such as regulatory T cells and macrophages, as well as components of the renal vasculature, control purinergic receptor-mediated effects on target tissues within the kidney. The role of CD39 as a rheostat that can have an impact on purinergic signalling in both acute and chronic inflammation is increasingly supported by the literature, as detailed in this Review. Better understanding of these purinergic processes and development of novel drugs targeting these pathways could lead to effective therapies for the management of acute and chronic kidney disease.
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Cao Z, Yan L, Shen Z, Chen Y, Shi Y, He X, Zhou N. A novel splice variant of Gαq-coupled Bombyx CAPA-PVK receptor 1 functions as a specific Gαi/o-linked receptor for CAPA-PK. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118718. [PMID: 32289337 DOI: 10.1016/j.bbamcr.2020.118718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 01/04/2023]
Abstract
Alternative splicing enables G protein-coupled receptor (GPCR) genes to greatly increase the number of structurally and functionally distinct receptor isoforms. However, the functional role and relevance of the individual GPCR splice variants in regulating physiological processes are still to be assessed. A naturally occurring alternative splice variant of Bombyx CAPA-PVK receptor, BomCAPA-PVK-R1-Δ341, has been shown to act as a dominant-negative protein to regulate cell surface expression and function of the canonical CAPA-PVK receptor. Herein, using functional assays, we identify the splice variant Δ341 as a specific receptor for neuropeptide CAPA-PK, and upon activation, Δ341 signals to ERK1/2 pathway. Further characterization demonstrates that Δ341 couples to Gαi/o, distinct from the Gαq-coupled canonical CAPA-PVK receptor, triggering ERK1/2 phosphorylation through Gβγ-PI3K-PKCζ signaling cascade. Moreover, our ELISA data show that the ligand-dependent internalization of the splice variant Δ341 is significantly impaired due to lack of GRKs-mediated phosphorylation sites. Our findings highlight the potential of this knowledge for molecular, pharmacological and physiological studies on GPCR splice variants in the future.
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Affiliation(s)
- Zheng Cao
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Lili Yan
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Zhangfei Shen
- Department of Economic Zoology, College of Animal Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yu Chen
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Ying Shi
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiaobai He
- College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu 212018, China
| | - Naiming Zhou
- Institute of Biochemistry, College of Life Sciences, Zijingang Campus, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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Erblang M, Drogou C, Gomez-Merino D, Metlaine A, Boland A, Deleuze JF, Thomas C, Sauvet F, Chennaoui M. The Impact of Genetic Variations in ADORA2A in the Association between Caffeine Consumption and Sleep. Genes (Basel) 2019; 10:E1021. [PMID: 31817803 PMCID: PMC6947650 DOI: 10.3390/genes10121021] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 11/26/2019] [Accepted: 12/05/2019] [Indexed: 02/06/2023] Open
Abstract
ADORA2A has been shown to be responsible for the wakefulness-promoting effect of caffeine and the 1976T>C genotype (SNP rs5751876, formerly 1083T>C) to contribute to individual sensitivity to caffeine effects on sleep. We investigate the association between six single nucleotide polymorphisms (SNP) from ADORA2A and self-reported sleep characteristics and caffeine consumption in 1023 active workers of European ancestry aged 18-60 years. Three groups of caffeine consumers were delineated: low (0-50 mg/day, less than one expresso per day), moderate (51-300 mg/day), and high (>300 mg/day). We found that at caffeine levels higher than 300 mg/day, total sleep time (TST) decreased (F = 13.9, p < 0.01), with an increase of insomnia (ORa [95%CI] = 1.5 [1.1-1.9]) and sleep complaints (ORa [95%CI] = 1.9 [1.1-3.3]), whatever the ADORA2A polymorphism. Odds ratios were adjusted (ORa) for sex, age, and tobacco. However, in low caffeine consumers, lower TST was observed in the T allele compared to homozygote rs5751876 and rs3761422 C carriers. Conversely, higher TST was observed in rs2298383 T allele compared to C and in rs4822492G allele compared to the homozygote C (p < 0.05). These 4 SNPs are in strong linkage disequilibrium. Haplotype analysis confirmed the influence of multiple ADORA2a SNPs on TST. In addition, the rs2298383 T and rs4822492 G alleles were associated with higher risk of sleep complaints (Ora = 1.9 [1.2-3.1] and Ora = 1.5 [1.1-2.1]) and insomnia (Ora = 1.5 [1.3-2.5] and Ora = 1.9 [1.3-3.2). The rs5751876 T allele was associated with a decreased risk of sleep complaints (Ora = 0.7 [0.3-0.9]) and insomnia (Ora = 0.5 [0.3-0.9]). Our results identified ADORA2A polymorphism influences in the less-than-300-mg-per-day caffeine consumers. This opens perspectives on the diagnosis and pharmacology of sleep complaints and caffeine chronic consumption.
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Affiliation(s)
- Mégane Erblang
- Unité Fatigue et Vigilance, Institut de Recherche Biomédicale des Armées (IRBA), EA 7330 VIFASOM, Université de Paris, 75004 Paris, France; (M.E.); (C.D.); (D.G.-M.); (F.S.)
| | - Catherine Drogou
- Unité Fatigue et Vigilance, Institut de Recherche Biomédicale des Armées (IRBA), EA 7330 VIFASOM, Université de Paris, 75004 Paris, France; (M.E.); (C.D.); (D.G.-M.); (F.S.)
| | - Danielle Gomez-Merino
- Unité Fatigue et Vigilance, Institut de Recherche Biomédicale des Armées (IRBA), EA 7330 VIFASOM, Université de Paris, 75004 Paris, France; (M.E.); (C.D.); (D.G.-M.); (F.S.)
| | - Arnaud Metlaine
- EA 7330 VIFASOM, Université de Paris, APHP, Hôtel Dieu, Centre du Sommeil et de la Vigilance, 75004 Paris, France;
| | - Anne Boland
- Centre National de Recherche en Génomique Humaine (CNRGH), Institut de Biologie François Jacob, CEA, Université Paris-Saclay, 91057 Evry, France; (A.B.)
| | - Jean François Deleuze
- Centre National de Recherche en Génomique Humaine (CNRGH), Institut de Biologie François Jacob, CEA, Université Paris-Saclay, 91057 Evry, France; (A.B.)
| | - Claire Thomas
- Unité de Biologie Intégrative des Adaptations à l’Exercice, Université Evry, Université, Paris-Saclay, 91025 Evry, France;
| | - Fabien Sauvet
- Unité Fatigue et Vigilance, Institut de Recherche Biomédicale des Armées (IRBA), EA 7330 VIFASOM, Université de Paris, 75004 Paris, France; (M.E.); (C.D.); (D.G.-M.); (F.S.)
| | - Mounir Chennaoui
- Unité Fatigue et Vigilance, Institut de Recherche Biomédicale des Armées (IRBA), EA 7330 VIFASOM, Université de Paris, 75004 Paris, France; (M.E.); (C.D.); (D.G.-M.); (F.S.)
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23
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Sriram K, Wiley SZ, Moyung K, Gorr MW, Salmerón C, Marucut J, French RP, Lowy AM, Insel PA. Detection and Quantification of GPCR mRNA: An Assessment and Implications of Data from High-Content Methods. ACS OMEGA 2019; 4:17048-17059. [PMID: 31646252 PMCID: PMC6796235 DOI: 10.1021/acsomega.9b02811] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 09/12/2019] [Indexed: 05/04/2023]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of membrane receptors and targets for approved drugs. The analysis of GPCR expression is, thus, important for drug discovery and typically involves messenger RNA (mRNA)-based methods. We compared transcriptomic complementary DNA (cDNA) (Affymetrix) microarrays, RNA sequencing (RNA-seq), and quantitative polymerase chain reaction (qPCR)-based TaqMan arrays for their ability to detect and quantify expression of endoGPCRs (nonchemosensory GPCRs with endogenous agonists). In human pancreatic cancer-associated fibroblasts, RNA-seq and TaqMan arrays yielded closely correlated values for GPCR number (∼100) and expression levels, as validated by independent qPCR. By contrast, the microarrays failed to identify ∼30 such GPCRs and generated data poorly correlated with results from those methods. RNA-seq and TaqMan arrays also yielded comparable results for GPCRs in human cardiac fibroblasts, pancreatic stellate cells, cancer cell lines, and pulmonary arterial smooth muscle cells. The magnitude of mRNA expression for several Gq/11-coupled GPCRs predicted cytosolic calcium increase and cell migration by cognate agonists. RNA-seq also revealed splice variants for endoGPCRs. Thus, RNA-seq and qPCR-based arrays are much better suited than transcriptomic cDNA microarrays for assessing GPCR expression and can yield results predictive of functional responses, findings that have implications for GPCR biology and drug discovery.
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Affiliation(s)
- Krishna Sriram
- Department of Pharmacology, Department of Surgery, Moores Cancer Center, and Department of
Medicine, University of California, San
Diego, La Jolla, California 92093-0636, United States
| | - Shu Z. Wiley
- Department of Pharmacology, Department of Surgery, Moores Cancer Center, and Department of
Medicine, University of California, San
Diego, La Jolla, California 92093-0636, United States
| | - Kevin Moyung
- Department of Pharmacology, Department of Surgery, Moores Cancer Center, and Department of
Medicine, University of California, San
Diego, La Jolla, California 92093-0636, United States
| | - Matthew W. Gorr
- Department of Pharmacology, Department of Surgery, Moores Cancer Center, and Department of
Medicine, University of California, San
Diego, La Jolla, California 92093-0636, United States
| | - Cristina Salmerón
- Department of Pharmacology, Department of Surgery, Moores Cancer Center, and Department of
Medicine, University of California, San
Diego, La Jolla, California 92093-0636, United States
| | - Jordin Marucut
- Department of Pharmacology, Department of Surgery, Moores Cancer Center, and Department of
Medicine, University of California, San
Diego, La Jolla, California 92093-0636, United States
| | - Randall P. French
- Department of Pharmacology, Department of Surgery, Moores Cancer Center, and Department of
Medicine, University of California, San
Diego, La Jolla, California 92093-0636, United States
| | - Andrew M. Lowy
- Department of Pharmacology, Department of Surgery, Moores Cancer Center, and Department of
Medicine, University of California, San
Diego, La Jolla, California 92093-0636, United States
| | - Paul A. Insel
- Department of Pharmacology, Department of Surgery, Moores Cancer Center, and Department of
Medicine, University of California, San
Diego, La Jolla, California 92093-0636, United States
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Peptides derived from the extracellular domain of the somatostatin receptor splicing variant SST5TMD4 increase malignancy in multiple cancer cell types. Transl Res 2019; 211:147-160. [PMID: 30904441 DOI: 10.1016/j.trsl.2019.02.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 02/06/2019] [Accepted: 02/26/2019] [Indexed: 12/19/2022]
Abstract
Extracellular fragments derived from plasma membrane receptors can play relevant roles in the development/progression of tumor pathologies, thereby offering novel diagnostic or therapeutic opportunities. The truncated variant of somatostatin receptor subtype-5, SST5TMD4, is an aberrantly spliced receptor with 4 transmembrane domains, highly overexpressed in several tumor types, whose C-terminal tail is exposed towards the extracellular matrix, and could therefore be the substrate for proteolytic enzymes. In silico analysis implemented herein predicted 2 possible cleavage sites for metalloproteases MMP2, 9, 14, and 16 in its sequence, which could generate 3 releasable peptides. Of note, expression of those MMPs was directly correlated with SST5TMD4 in several cancer-derived cell lines (ie neuroendocrine tumors and prostate, breast, and liver cancers). Moreover, incubation with SST5TMD4-derived peptides enhanced malignancy features in all cancer cell types tested (ie proliferation, migration, etc.) and blunted the antiproliferative response to somatostatin in QGP-1 cells, acting probably through PI3K/AKT and/or MEK/ERK signaling pathways and the modulation of key cancer-associated genes (eg MMPs, MKI67, ACTR2/3, CD24/44). These results suggest that SST5TMD4-derived peptides could contribute to the strong oncogenic role of SST5TMD4 observed in multiple tumor pathologies, and, therefore, represent potential candidates to identify novel diagnostic, prognostic, or therapeutic targets in cancer.
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25
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Mapping and identification of potential target genes from short-RNA seq for the control of Pieris rapae larvae. Genomics 2019; 112:1464-1476. [PMID: 31450005 DOI: 10.1016/j.ygeno.2019.08.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 06/25/2019] [Accepted: 08/21/2019] [Indexed: 01/15/2023]
Abstract
Pieris rapae is a serious pest of brassicas worldwide. We performed de novo assembly of P. rapae transcriptome by next-generation sequencing and assembled approximately 65,727,422 clean paired-end reads into 32,118 unigenes, of which 13,585 were mapped to 255 pathways in the KEGG database. A total of 6173 novel transcripts were identified from reads directly mapped to P. rapae genome. Additionally, 1490 SSRs, 301,377 SNPs, and 29,284 InDels were identified as potential molecular markers to explore polymorphism within P. rapae populations. We screened and mapped 36 transcripts related to OBP, CSP, SNMP, PBAN, and OR. We analyzed the expression profiles of 7 selected genes involved in pheromone transport and degradation by quantitative real-time PCR; these genes are sex-specific and differentially expressed in the developmental stages. Overall, the comprehensive transcriptome resources described in this study could help understand and identify molecular targets particularly reproduction-related genes for developing effective P. rapae management tools.
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26
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Insel PA, Sriram K, Gorr MW, Wiley SZ, Michkov A, Salmerón C, Chinn AM. GPCRomics: An Approach to Discover GPCR Drug Targets. Trends Pharmacol Sci 2019; 40:378-387. [PMID: 31078319 PMCID: PMC6604616 DOI: 10.1016/j.tips.2019.04.001] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 03/17/2019] [Accepted: 04/03/2019] [Indexed: 01/14/2023]
Abstract
G protein-coupled receptors (GPCRs) are targets for ∼35% of approved drugs but only ∼15% of the ∼800 human GPCRs are currently such targets. GPCRomics, the use of unbiased, hypothesis-generating methods [e.g., RNA-sequencing (RNA-seq)], with tissues and cell types to identify and quantify GPCR expression, has led to the discovery of previously unrecognized GPCRs that contribute to functional responses and pathophysiology and that may be therapeutic targets. The combination of GPCR expression data with validation studies (e.g., signaling and functional activities) provides opportunities for the discovery of disease-relevant GPCR targets and therapeutics. Here, we review insights from GPCRomic approaches, gaps in knowledge, and future directions by which GPCRomics can advance GPCR biology and the discovery of new GPCR-targeted drugs.
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Affiliation(s)
- Paul A Insel
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA; Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Krishna Sriram
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Matthew W Gorr
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Shu Z Wiley
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Alexander Michkov
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Cristina Salmerón
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Amy M Chinn
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
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27
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Lattanzi R, Maftei D, Fullone MR, Miele R. Identification and characterization of Prokineticin receptor 2 splicing variant and its modulation in an animal model of Alzheimer's disease. Neuropeptides 2019; 73:49-56. [PMID: 30553543 DOI: 10.1016/j.npep.2018.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 10/25/2018] [Accepted: 11/26/2018] [Indexed: 10/27/2022]
Affiliation(s)
- Roberta Lattanzi
- Dipartimento di Fisiologia e Farmacologia "Vittorio Erspamer", Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Daniela Maftei
- Dipartimento di Scienze Biochimiche A. Rossi Fanelli, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Maria Rosaria Fullone
- Dipartimento di Scienze Biochimiche A. Rossi Fanelli, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy
| | - Rossella Miele
- Dipartimento di Scienze Biochimiche A. Rossi Fanelli, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Roma, Italy.
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Bräuer KE, Brockers K, Moneer J, Feuchtinger A, Wollscheid-Lengeling E, Lengeling A, Wolf A. Phylogenetic and genomic analyses of the ribosomal oxygenases Riox1 (No66) and Riox2 (Mina53) provide new insights into their evolution. BMC Evol Biol 2018; 18:96. [PMID: 29914368 PMCID: PMC6006756 DOI: 10.1186/s12862-018-1215-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 06/07/2018] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Translation of specific mRNAs can be highly regulated in different cells, tissues or under pathological conditions. Ribosome heterogeneity can originate from variable expression or post-translational modifications of ribosomal proteins. The ribosomal oxygenases RIOX1 (NO66) and RIOX2 (MINA53) modify ribosomal proteins by histidine hydroxylation. A similar mechanism is present in prokaryotes. Thus, ribosome hydroxylation may be a well-conserved regulatory mechanism with implications in disease and development. However, little is known about the evolutionary history of Riox1 and Riox2 genes and their encoded proteins across eukaryotic taxa. RESULTS In this study, we have analysed Riox1 and Riox2 orthologous genes from 49 metazoen species and have constructed phylogenomic trees for both genes. Our genomic and phylogenetic analyses revealed that Arthropoda, Annelida, Nematoda and Mollusca lack the Riox2 gene, although in the early phylum Cnidaria both genes, Riox1 and Riox2, are present and expressed. Riox1 is an intronless single-exon-gene in several species, including humans. In contrast to Riox2, Riox1 is ubiquitously present throughout the animal kingdom suggesting that Riox1 is the phylogenetically older gene from which Riox2 has evolved. Both proteins have maintained a unique protein architecture with conservation of active sites within the JmjC domains, a dimerization domain, and a winged-helix domain. In addition, Riox1 proteins possess a unique N-terminal extension domain. Immunofluorescence analyses in Hela cells and in Hydra vulgaris identified a nucleolar localisation signal within the extended N-terminal domain of human RIOX1 and an altered subnuclear localisation for the Hydra Riox2. CONCLUSIONS Conserved active site residues and uniform protein domain architecture suggest a consistent enzymatic activity within the Riox orthologs throughout evolution. However, differences in genomic architecture, like single exon genes and alterations in subnuclear localisation, as described for Hydra, point towards adaption mechanisms that may correlate with taxa- or species-specific requirements. The diversification of Riox1/Riox2 gene structures throughout evolution suggest that functional requirements in expression of protein isoforms and/or subcellular localisation of proteins may have evolved by adaptation to lifestyle.
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Affiliation(s)
- Katharina E Bräuer
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München-German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Kevin Brockers
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München-German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
| | - Jasmin Moneer
- Department of Biology II, Ludwig Maximillians University, Munich, Großhaderner Strasse 2, 82152 Planegg-, Martinsried, Germany
| | - Annette Feuchtinger
- Research Unit Analytical Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Ingolstädter Landstr. 1, 85764, Neuherberg, Germany
| | - Evi Wollscheid-Lengeling
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Andreas Lengeling
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK.,Present address: Max-Planck-Society, Administrative Headquarters, Hofgartenstr. 8, 80539, Munich, Germany
| | - Alexander Wolf
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München-German Research Center for Environmental Health, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany.
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Fodor J, Hull JJ, Köblös G, Jacquin-Joly E, Szlanka T, Fónagy A. Identification and functional characterization of the pheromone biosynthesis activating neuropeptide receptor isoforms from Mamestra brassicae. Gen Comp Endocrinol 2018; 258:60-69. [PMID: 28579335 DOI: 10.1016/j.ygcen.2017.05.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 05/26/2017] [Accepted: 05/31/2017] [Indexed: 11/19/2022]
Abstract
In most moth species, including Mamestra brassicae, pheromone biosynthesis activating neuropeptide (PBAN) regulates pheromone production. Generally, PBAN acts directly on the pheromone gland (PG) cells via its specific G protein-coupled receptor (i.e. PBANR) with Ca2+ as a second messenger. In this study, we identified cDNAs encoding three variants (A, B and C) of the M. brassicae PBANR (Mambr-PBANR). The full-length coding sequences were transiently expressed in cultured Trichoplusia ni cells and Sf9 cells for functional characterization. All three isoforms dose-dependently mobilized extracellular Ca2+ in response to PBAN analogs with Mambr-PBANR-C exhibiting the greatest sensitivity. Fluorescent confocal microscopy imaging studies demonstrated binding of a rhodamine red-labeled ligand (RR10CPBAN) to all three Mambr-PBANR isoforms. RR10CPBAN binding did not trigger ligand-induced internalization in cells expressing PBANR-A, but did in cells expressing the PBANR-B and -C isoforms. Furthermore, activation of the PBANR-B and -C isoforms with the 18 amino acid Mambr-pheromonotropin resulted in co-localization with a Drosophila melanogaster arrestin homolog (Kurtz), whereas stimulation with an unrelated peptide had no effect. PCR-based profiling of the three transcripts revealed a basal level of expression throughout development with a dramatic increase in PG transcripts from the day of adult emergence with PBANR-C being the most abundant.
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Affiliation(s)
- József Fodor
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, H-1022 Budapest, Hungary
| | - J Joe Hull
- Agricultural Research Service, United States Department of Agriculture, Arid Land Agricultural Research Center, Maricopa, AZ, USA
| | - Gabriella Köblös
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, H-1022 Budapest, Hungary.
| | - Emmanuelle Jacquin-Joly
- INRA iEES-Paris, Institute of Ecology and Environmental Sciences, Route de Saint-Cyr, Cedex 78026 Versailles, France
| | - Tamás Szlanka
- Institute of Biochemistry, Biological Research Centre, Hungarian Academy of Sciences, H-6726 Szeged, Hungary
| | - Adrien Fónagy
- Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, H-1022 Budapest, Hungary
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Spitsin S, Pappa V, Douglas SD. Truncation of neurokinin-1 receptor-Negative regulation of substance P signaling. J Leukoc Biol 2018; 103:1043-1051. [PMID: 29345372 DOI: 10.1002/jlb.3mir0817-348r] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/22/2017] [Accepted: 12/07/2017] [Indexed: 12/21/2022] Open
Abstract
Substance P (SP) is a tachykinin peptide, which triggers intracellular signaling in the nervous and immune systems, as well as, other local and systemic events. The interaction between SP and its receptor, neurokinin-1 receptor (NK1R), results in major downstream cellular actions, which include changes in calcium fluxes, ERK, and p21-activated kinase phosphorylation and NFκB activation. Two naturally occurring variants of the NK1R, the full-length, 407 aa receptor (NK1R-F) and the truncated, 311 aa isoform (NK1R-T), mediate the actions of SP. Receptor truncation partially disrupts signaling motifs of the carboxyl tail, a critical site for mediating NK1R signaling, resulting in a "less-efficient" receptor. Although NK1R-F is the predominant isoform in the central and peripheral nervous systems, NK1R-T is expressed in several tissues and cells, which include monocytes, NK cells, and T-cells. The SP binding domain is not affected by truncation and this site is identical in both NK1R receptor isoforms. However, while cells expressing NK1R-F respond to nanomolar concentrations of SP, monocyte and macrophage activation, mediated through NK1R-T, requires micromolar concentrations of SP in order to elicit signaling responses. Elevated plasma levels of SP are associated with increased inflammatory responses and NK1R antagonists reduce inflammation and cytokine production in vivo. This mini review presents and discusses the novel hypothesis that the expression of NK1R-T on immune system cells prevents immune activation in a milieu, which usually contains low concentrations of SP and, thus, maintains immune homeostasis. In contrast, in the activated neuronal microenvironment, when SP levels reach the threshold at tissue sites, SP promotes immune activation and modulates monocyte/macrophage polarization.
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Affiliation(s)
- Sergei Spitsin
- Department of Pediatrics, Division of Allergy and Immunology, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania, USA
| | - Vasiliki Pappa
- Department of Pediatrics, Division of Allergy and Immunology, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania, USA
| | - Steven D Douglas
- Department of Pediatrics, Division of Allergy and Immunology, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Margari L, Legrottaglie AR, Vincenti A, Coppola G, Operto FF, Buttiglione M, Cassano A, Bartolomeo N, Mariggiò MA. Association between SCN1A gene polymorphisms and drug resistant epilepsy in pediatric patients. Seizure 2018; 55:30-35. [PMID: 29353705 DOI: 10.1016/j.seizure.2018.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 12/29/2017] [Accepted: 01/02/2018] [Indexed: 12/16/2022] Open
Abstract
PURPOSE "Single Nucleotide Polymorphisms (SNPs)" could be an important explanation of drug resistance in epilepsy. The aim of this study was to investigate if genetic polymorphisms (SNPs) of the SCN1A gene could influence the response to anti - epileptic drugs (AED) and if they could predispose to a drug resistant epilepsy in pediatric patients. METHODS We investigated SNPs in exon and intronic regions of the SCN1A gene in a sample of 120 pediatric patients, in both drug-resistant and drug-responsive patients. Association between polymorphisms and refractory epilepsy were investigated by comparing SNPs in exon and intronic regions between the two groups. The genotypes of each intronic polymorphism in the drug-resistant group was analyzed. Odds ratios and confidence intervals were calculated. RESULTS None of the SNPs identified in exons of the SCN1A gene were associated with drug-resistance. In the intronic regions, a statistically significant difference was found in the prevalence of three polymorphisms was found between the two patient groups (rs6730344A/C, rs6732655A/T, rs10167228A/T). The analysis of the genotypes of each intronic polymorphism in the drug-resistant group revealed that the AA and AT genotypes for the rs1962842 polymorphism are associated with an increased risk of developing drug resistance compared to TT genotype. CONCLUSION The intronic rs6730344, rs6732655 and rs10167228 polymorphisms of the SCN1A gene are a potential risk factors for drug resistance. AA e AT genotype of the rs1962842 intronic polymorphism also emerged as a risk factor in the drug resistant group. Therefore, polymorphisms of the SCN1A gene could play a role in the response to AED in patients with drug-resistant epilepsy, with important implications for clinical practice.
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Affiliation(s)
- Lucia Margari
- Child Neuropsychiatry Unit, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Italy.
| | - Anna R Legrottaglie
- Child Neuropsychiatry Unit, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Italy
| | - Alessandra Vincenti
- Department of Biomedical Sciences and Human Oncology, University of Bari "Aldo Moro", Italy
| | - Giangennaro Coppola
- Child Neuropsychiatry Unit, Department of Medicine, Surgery and Dentistry, University of Salerno, Italy
| | - Francesca F Operto
- Child Neuropsychiatry Unit, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Italy
| | - Maura Buttiglione
- Child Neuropsychiatry Unit, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Italy
| | - Amalia Cassano
- Department of Biomedical Sciences and Human Oncology, University of Bari "Aldo Moro", Italy
| | - Nicola Bartolomeo
- Department of Biomedical Sciences and Human Oncology, University of Bari "Aldo Moro", Italy
| | - Maria A Mariggiò
- Department of Biomedical Sciences and Human Oncology, University of Bari "Aldo Moro", Italy
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Mechaly AS, Tovar Bohórquez MO, Mechaly AE, Suku E, Pérez MR, Giorgetti A, Ortí G, Viñas J, Somoza GM. Evidence of Alternative Splicing as a Regulatory Mechanism for Kissr2 in Pejerrey Fish. Front Endocrinol (Lausanne) 2018; 9:604. [PMID: 30386295 PMCID: PMC6200147 DOI: 10.3389/fendo.2018.00604] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 09/21/2018] [Indexed: 11/16/2022] Open
Abstract
Kisspeptin receptors are G-Protein-Coupled Receptors that regulate GnRH synthesis and release in vertebrates. Here, we report the gene structure of two kisspeptin receptors (kissr2 and kissr3) in pejerrey fish. Genomic analysis exposed a gene structure with 5 exons and 4 introns for kissr2 and 6 exons and 5 introns for kissr3. Two alternative variants for both genes, named kissr2_v1 and _v2, and kissr3_v1 and v2, were revealed by gene expression analyses of several tissues. For both receptors, these variants were originated by alternative splicing retaining intron 3 and intron 4 for kissr2_v2 and kissr3_v2, respectively. In the case of kissr2, the intron retention introduced two stop codons leading to a putatively truncated protein whereas for kissr3, the intron retention produced a reading shift leading to a stop codon in exon 5. Modeling and structural analysis of Kissr2 and Kissr3 spliced variants revealed that truncation of the proteins may lead to non-functional proteins, as the structural elements missing are critical for receptor function. To understand the functional significance of splicing variants, the expression pattern for kissr2 was characterized on fish subjected to different diets. Fasting induced an up-regulation of kissr2_v1 in the hypothalamus, a brain region implicated in control of reproduction and food intake, with no expression of kissr2_v2. On the other hand, fasting did not elicit differential expression in testes and habenula. These results suggest that alternative splicing may play a role in regulating Kissr2 function in pejerrey.
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Affiliation(s)
- Alejandro S. Mechaly
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (CONICET-UNSAM), Buenos Aires, Argentina
- *Correspondence: Alejandro S. Mechaly
| | - M. Oswaldo Tovar Bohórquez
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (CONICET-UNSAM), Buenos Aires, Argentina
| | - Ariel E. Mechaly
- Institut Pasteur, Platforme de Cristallographie and CNRS UMR 3528, Paris, France
| | - Eda Suku
- Department of Biotechnology, University of Verona, Verona, Italy
| | - María Rita Pérez
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (CONICET-UNSAM), Buenos Aires, Argentina
| | | | - Guillermo Ortí
- Department of Biological Sciences, George Washington University, Washington, DC, United States
| | - Jordi Viñas
- Laboratori d'Ictiologia Genètica, Departament de Biologia, Universitat de Girona, Girona, Spain
| | - Gustavo M. Somoza
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús (CONICET-UNSAM), Buenos Aires, Argentina
- Gustavo M. Somoza
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Schober DA, Croy CH, Ruble CL, Tao R, Felder CC. Identification, expression and functional characterization of M4L, a muscarinic acetylcholine M4 receptor splice variant. PLoS One 2017; 12:e0188330. [PMID: 29211764 PMCID: PMC5718406 DOI: 10.1371/journal.pone.0188330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/03/2017] [Indexed: 11/24/2022] Open
Abstract
Rodent genomic alignment sequences support a 2-exon model for muscarinic M4 receptor. Using this model a novel N-terminal extension was discovered in the human muscarinic acetylcholine M4 receptor. An open reading frame was discovered in the human, mouse and rat with a common ATG (methionine start codon) that extended the N-terminus of the muscarinic acetylcholine M4 receptor subtype by 155 amino acids resulting in a longer variant. Transcriptional evidence for this splice variant was confirmed by RNA-Seq and RT-PCR experiments performed from human donor brain prefrontal cortices. We detected a human upstream exon indicating the translation of the mature longer M4 receptor transcript. The predicted size for the longer two-exon M4 receptor splice variant with the additional 155 amino acid N-terminal extension, designated M4L is 69.7 kDa compared to the 53 kDa canonical single exon M4 receptor (M4S). Western blot analysis from a mammalian overexpression system, and saturation radioligand binding with [3H]-NMS (N-methyl-scopolamine) demonstrated the expression of this new splice variant. Comparative pharmacological characterization between the M4L and M4S receptors revealed that both the orthosteric and allosteric binding sites for both receptors were very similar despite the addition of an N-terminal extension.
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Affiliation(s)
- Douglas A. Schober
- Neuroscience, Lilly Research Laboratories, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Carrie H. Croy
- Neuroscience, Lilly Research Laboratories, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Cara L. Ruble
- Neuroscience, Lilly Research Laboratories, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, Indiana, United States of America
| | - Ran Tao
- Lieber Institute for Brain Development, Baltimore, Maryland, United States of America
| | - Christian C. Felder
- Neuroscience, Lilly Research Laboratories, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, Indiana, United States of America
- * E-mail:
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Shen Z, Chen Y, Hong L, Cui Z, Yang H, He X, Shi Y, Shi L, Han F, Zhou N. BNGR-A25L and -A27 are two functional G protein-coupled receptors for CAPA periviscerokinin neuropeptides in the silkworm Bombyx mori. J Biol Chem 2017; 292:16554-16570. [PMID: 28842502 DOI: 10.1074/jbc.m117.803445] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 08/11/2017] [Indexed: 01/14/2023] Open
Abstract
CAPA peptides, such as periviscerokinin (PVK), are insect neuropeptides involved in many signaling pathways controlling, for example, metabolism, behavior, and reproduction. They are present in a large number of insects and, together with their cognate receptors, are important for research into approaches for improving insect control. However, the CAPA receptors in the silkworm (Bombyx mori) insect model are unknown. Here, we cloned cDNAs of two putative CAPA peptide receptor genes, BNGR-A27 and -A25, from the brain of B. mori larvae. We found that the predicted BNGR-A27 ORF encodes 450 amino acids and that one BNGR-A25 splice variant encodes a full-length isoform (BNGR-A25L) of 418 amino acid residues and another a short isoform (BNGR-A25S) of 341 amino acids with a truncated C-terminal tail. Functional assays indicated that both BNGR-A25L and -A27 are activated by the PVK neuropeptides Bom-CAPA-PVK-1 and -PVK-2, leading to a significant increase in cAMP-response element-controlled luciferase activity and Ca2+ mobilization in a Gq inhibitor-sensitive manner. In contrast, BNGR-A25S was not significantly activated in response to the PVK peptides. Moreover, Bom-CAPA-PVK-1 directly bound to BNGR-A25L and -A27, but not BNGR-A25S. Of note, CAPA-PVK-mediated ERK1/2 phosphorylation and receptor internalization confirmed that BNGR-A25L and -A27 are two canonical receptors for Bombyx CAPA-PVKs. However, BNGR-A25S alone is a nonfunctional receptor but serves as a dominant-negative protein for BNGR-A25L. These results provide evidence that BNGR-A25L and -A27 are two functional Gq-coupled receptors for Bombyx CAPA-PVKs, enabling the further elucidation of the endocrinological roles of Bom-CAPA-PVKs and their receptors in insect biology.
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Affiliation(s)
- Zhangfei Shen
- the Department of Economic Zoology, College of Animal Sciences, and
| | - Yu Chen
- From the Institute of Biochemistry, College of Life Sciences
| | - Lingjuan Hong
- the Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zijingang Campus, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Zhenteng Cui
- the Department of Economic Zoology, College of Animal Sciences, and
| | - Huipeng Yang
- From the Institute of Biochemistry, College of Life Sciences
| | - Xiaobai He
- From the Institute of Biochemistry, College of Life Sciences
| | - Ying Shi
- From the Institute of Biochemistry, College of Life Sciences
| | - Liangen Shi
- the Department of Economic Zoology, College of Animal Sciences, and
| | - Feng Han
- the Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zijingang Campus, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Naiming Zhou
- From the Institute of Biochemistry, College of Life Sciences,
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Xu J, Lu Z, Narayan A, Le Rouzic VP, Xu M, Hunkele A, Brown TG, Hoefer WF, Rossi GC, Rice RC, Martínez-Rivera A, Rajadhyaksha AM, Cartegni L, Bassoni DL, Pasternak GW, Pan YX. Alternatively spliced mu opioid receptor C termini impact the diverse actions of morphine. J Clin Invest 2017; 127:1561-1573. [PMID: 28319053 DOI: 10.1172/jci88760] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 01/12/2017] [Indexed: 12/22/2022] Open
Abstract
Extensive 3' alternative splicing of the mu opioid receptor gene OPRM1 creates multiple C-terminal splice variants. However, their behavioral relevance remains unknown. The present study generated 3 mutant mouse models with truncated C termini in 2 different mouse strains, C57BL/6J (B6) and 129/SvEv (129). One mouse truncated all C termini downstream of Oprm1 exon 3 (mE3M mice), while the other two selectively truncated C-terminal tails encoded by either exon 4 (mE4M mice) or exon 7 (mE7M mice). Studies of these mice revealed divergent roles for the C termini in morphine-induced behaviors, highlighting the importance of C-terminal variants in complex morphine actions. In mE7M-B6 mice, the exon 7-associated truncation diminished morphine tolerance and reward without altering physical dependence, whereas the exon 4-associated truncation in mE4M-B6 mice facilitated morphine tolerance and reduced morphine dependence without affecting morphine reward. mE7M-B6 mutant mice lost morphine-induced receptor desensitization in the brain stem and hypothalamus, consistent with exon 7 involvement in morphine tolerance. In cell-based studies, exon 7-associated variants shifted the bias of several mu opioids toward β-arrestin 2 over G protein activation compared with the exon 4-associated variant, suggesting an interaction of exon 7-associated C-terminal tails with β-arrestin 2 in morphine-induced desensitization and tolerance. Together, the differential effects of C-terminal truncation illustrate the pharmacological importance of OPRM1 3' alternative splicing.
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Abstract
Opioids are the gold-standard treatment for severe pain. However, potentially life-threatening side effects decrease the safety and effectiveness of these compounds. The addiction liability of these drugs has led to the current epidemic of opioid abuse in the US. Extensive research efforts have focused on trying to dissociate the analgesic properties of opioids from their undesirable side effects. Splice variants of the mu opioid receptor (MOR), which mediates opioid actions, have unique pharmacological properties and anatomic distributions that make them attractive candidates for therapeutic pain relief. In this issue of the JCI, Xu et al. show that specific C-terminal regions of the MOR can modulate side effects without altering analgesia. This discovery greatly improves our understanding of opioid side effects and suggests intriguing therapeutic approaches that could improve both the safety and long-term effectiveness of opioids.
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Identification of Three Novel Splicing Variants and Expression Analysis of Chicken GPR1 Gene. BIOMED RESEARCH INTERNATIONAL 2017; 2017:1074054. [PMID: 28203567 PMCID: PMC5292125 DOI: 10.1155/2017/1074054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 11/08/2016] [Accepted: 11/24/2016] [Indexed: 11/18/2022]
Abstract
GPR1 is a G protein-coupled receptor that plays critical roles in eukaryotic cells: typically, response to glucose stimulation, lipid accumulation, and transmitting nutrition signals to cAMP pathway. However, the alternative splicing of the GPR1 gene and its expression pattern in chicken tissues and ovarian follicles were unknown. In our current study, we used RACE-PCR to identify three GPR1 variants, including the full-length variant (GPR1-va1) and two alternatively spliced variants (GPR1-va2, GPR1-vb). Quantitative real-time PCR examined the expression pattern of GPR1 mRNA in chicken tissues and ovarian follicles. The result reveals that the coding sequence of the three variants cDNA is 1053, 1053, and 627 bp in length, encoding 350, 350, and 208 amino acids, respectively. The three variants of GPR1 show similar tissue distributions; GPR1 expression was abundant in the abdominal fat, lung, and heart. With the follicular development, the expression of GPR1 gene gradually increased, and GPR1-va1 and GPR1-va2 spliced variants expression in F2 were significantly higher than in F5, F4, and prehierarchical follicles (P < 0.05). Taken together, we found three novel variants of GPR1, and the results of GPR1 expression profiling in adipose tissues and ovarian follicles suggest that GPR1 may play a significant role in the lipid accumulation and progression of follicular development.
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Variants of G protein-coupled receptors: a reappraisal of their role in receptor regulation. Biochem Soc Trans 2016; 44:589-94. [PMID: 27068974 DOI: 10.1042/bst20150239] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Indexed: 01/11/2023]
Abstract
Truncated or shorter forms of G protein-coupled receptors (GPCRs), originating by alternative splicing, have been considered physiologically irrelevant for a rather long time. Nevertheless, it is now recognized that alternative splicing variants of GPCRs greatly increase the total number of receptor isoforms and can regulate receptor trafficking and signalling. Furthermore, dimerization of these truncated variants with other receptors concurs to expand receptor diversity. Highly truncated variants of GPCRs, typically, are retained in the endoplasmic reticulum (ER) and by heteromerization prevent the wild-type receptor to reach the plasma membrane, exerting a dominant-negative effect on its function. This can be responsible for some pathological conditions but in some other cases, it can offer protection from a disease because the expression of the receptor, that is necessary for binding an infectious agent, is attenuated. Here, we propose a possible new mechanism of creation of truncated GPCR variants through an internal ribosome entry site (IRES), a nucleotide sequence that allows cap independent translation of proteins by recruiting the ribosome in proximity of an internal initiation codon. We suggest that an IRES, situated in the third cytoplasmic loop, could be responsible for the translation of the last two transmembrane (TM) regions of the muscarinic M2receptor. IRES driven expression of this C-terminal part of the muscarinic M2receptor could represent a novel and additional mechanism of receptor regulation.
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Mirnaghizadeh SV, Zendehdel M, Babapour V. Involvement of histaminergic and noradrenergic receptors in the oxytocin-induced food intake in neonatal meat-type chicks. Vet Res Commun 2016; 41:57-66. [DOI: 10.1007/s11259-016-9672-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 12/05/2016] [Indexed: 12/19/2022]
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40
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Di Roberto RB, Chang B, Trusina A, Peisajovich SG. Evolution of a G protein-coupled receptor response by mutations in regulatory network interactions. Nat Commun 2016; 7:12344. [PMID: 27487915 PMCID: PMC4976203 DOI: 10.1038/ncomms12344] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 06/24/2016] [Indexed: 12/17/2022] Open
Abstract
All cellular functions depend on the concerted action of multiple proteins organized in complex networks. To understand how selection acts on protein networks, we used the yeast mating receptor Ste2, a pheromone-activated G protein-coupled receptor, as a model system. In Saccharomyces cerevisiae, Ste2 is a hub in a network of interactions controlling both signal transduction and signal suppression. Through laboratory evolution, we obtained 21 mutant receptors sensitive to the pheromone of a related yeast species and investigated the molecular mechanisms behind this newfound sensitivity. While some mutants show enhanced binding affinity to the foreign pheromone, others only display weakened interactions with the network's negative regulators. Importantly, the latter changes have a limited impact on overall pathway regulation, despite their considerable effect on sensitivity. Our results demonstrate that a new receptor–ligand pair can evolve through network-altering mutations independently of receptor–ligand binding, and suggest a potential role for such mutations in disease. Co-evolution of a new receptor-ligand pair will affect the downstream signal transduction network. Here, the authors use experimental evolution of yeast mating receptor Ste2 to show the effect of enhanced binding affinity and weakened interactions with the network's negative regulators on protein evolution.
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Affiliation(s)
- Raphaël B Di Roberto
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada M5S 3G5
| | - Belinda Chang
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada M5S 3G5
| | - Ala Trusina
- Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen Ø 2100, Denmark
| | - Sergio G Peisajovich
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord Street, Toronto, Ontario, Canada M5S 3G5
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Donaldson LF, Beazley-Long N. Alternative RNA splicing: contribution to pain and potential therapeutic strategy. Drug Discov Today 2016; 21:1787-1798. [PMID: 27329269 PMCID: PMC5405051 DOI: 10.1016/j.drudis.2016.06.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 05/31/2016] [Accepted: 06/14/2016] [Indexed: 12/19/2022]
Abstract
Alternative pre-mRNA splicing generates multiple proteins from a single gene. Control of alternative splicing is a likely therapy in cancer and other disorders. Key molecules in pain pathways – GPCRs and channels – are alternatively spliced. It is proposed that alternative splicing may be a therapeutic target in pain.
Since the sequencing of metazoan genomes began, it has become clear that the number of expressed proteins far exceeds the number of genes. It is now estimated that more than 98% of human genes give rise to multiple proteins through alternative pre-mRNA splicing. In this review, we highlight the known alternative splice variants of many channels, receptors, and growth factors that are important in nociception and pain. Recently, pharmacological control of alternative splicing has been proposed as potential therapy in cancer, wet age-related macular degeneration, retroviral infections, and pain. Thus, we also consider the effects that known splice variants of molecules key to nociception/pain have on nociceptive processing and/or analgesic action, and the potential for control of alternative pre-mRNA splicing as a novel analgesic strategy.
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Affiliation(s)
- Lucy F Donaldson
- School of Life Sciences and Arthritis Research UK Pain Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Nicholas Beazley-Long
- School of Life Sciences and Arthritis Research UK Pain Centre, University of Nottingham, Nottingham NG7 2UH, UK
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Regan PM, Langford TD, Khalili K. Regulation and Functional Implications of Opioid Receptor Splicing in Opioid Pharmacology and HIV Pathogenesis. J Cell Physiol 2016; 231:976-85. [PMID: 26529364 PMCID: PMC4728022 DOI: 10.1002/jcp.25237] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/02/2015] [Indexed: 12/18/2022]
Abstract
Despite the identification and characterization of four opioid receptor subtypes and the genes from which they are encoded, pharmacological data does not conform to the predications of a four opioid receptor model. Instead, current studies of opioid pharmacology suggest the existence of additional receptor subtypes; however, no additional opioid receptor subtype has been identified to date. It is now understood that this discrepancy is due to the generation of multiple isoforms of opioid receptor subtypes. While several mechanisms are utilized to generate these isoforms, the primary mechanism involves alternative splicing of the pre-mRNA transcript. Extensive alternative splicing patterns for opioid receptors have since been identified and discrepancies in opioid pharmacology are now partially attributed to variable expression of these isoforms. Recent studies have been successful in characterizing the localization of these isoforms as well as their specificity in ligand binding; however, the regulation of opioid receptor splicing specificity is poorly characterized. Furthermore, the functional significance of individual receptor isoforms and the extent to which opioid- and/or HIV-mediated changes in the opioid receptor isoform profile contributes to altered opioid pharmacology or the well-known physiological role of opioids in the exacerbation of HIV neurocognitive dysfunction is unknown. As such, the current review details constitutive splicing mechanisms as well as the specific architecture of opioid receptor genes, transcripts, and receptors in order to highlight the current understanding of opioid receptor isoforms, potential mechanisms of their regulation and signaling, and their functional significance in both opioid pharmacology and HIV-associated neuropathology.
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Affiliation(s)
- Patrick M. Regan
- Department of Neuroscience and Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - T. Dianne Langford
- Department of Neuroscience and Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Kamel Khalili
- Department of Neuroscience and Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
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Ruble CL, Smith RM, Calley J, Munsie L, Airey DC, Gao Y, Shin JH, Hyde TM, Straub RE, Weinberger DR, Nisenbaum LK. Genomic structure and expression of the human serotonin 2A receptor gene (HTR2A) locus: identification of novel HTR2A and antisense (HTR2A-AS1) exons. BMC Genet 2016; 17:16. [PMID: 26738766 PMCID: PMC4702415 DOI: 10.1186/s12863-015-0325-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 12/22/2015] [Indexed: 01/16/2023] Open
Abstract
Background The serotonin 2A receptor is widely implicated in genetic association studies and remains an important drug target for psychiatric, neurological, and cardiovascular conditions. RNA sequencing redefined the architecture of the serotonin 2A receptor gene (HTR2A), revealing novel mRNA transcript isoforms utilizing unannotated untranslated regions of the gene. Expression of these untranslated regions is modulated by common single nucleotide polymorphisms (SNPs), namely rs6311. Previous studies did not fully capture the complexity of the sense- and antisense-encoded transcripts with respect to novel exons in the HTR2A gene locus. Here, we comprehensively catalogued exons and RNA isoforms for both HTR2A and HTR2A-AS1 using RNA-Seq from human prefrontal cortex and multiple mouse tissues. We subsequently tested associations between expression of newfound gene features and common SNPs in humans. Results We find that the human HTR2A gene spans ~66 kilobases and consists of 7, rather than 4 exons. Furthermore, the revised human HTR2A-AS1 gene spans ~474 kilobases and consists of 18, rather than 3 exons. Three HTR2A exons directly overlap with HTR2A-AS1 exons, suggesting potential for complementary nucleotide interactions. The repertoire of possible mouse Htr2a splice isoforms is remarkably similar to humans and we also find evidence for overlapping sense-antisense transcripts in the same relative positions as the human transcripts. rs6311 and SNPs in high linkage disequilibrium are associated with HTR2A-AS1 expression, in addition to previously described associations with expression of the extended 5’ untranslated region of HTR2A. Conclusions Our proposed HTR2A and HTR2A-AS1 gene structures dramatically differ from current annotations, now including overlapping exons on the sense and anti-sense strands. We also find orthologous transcript isoforms expressed in mice, providing opportunities to elucidate the biological roles of the human isoforms using a model system. Associations between rs6311 and expression of HTR2A and HTR2A-AS1 suggest this polymorphism is capable of modulating the expression of the sense or antisense transcripts. Still unclear is whether these SNPs act directly on the expression of the sense or antisense transcripts and whether overlapping exons are capable of interacting through complimentary base-pairing. Additional studies are necessary to determine the extent and nature of interactions between the SNPs and the transcripts prior to interpreting these findings in the context of phenotypes associated with HTR2A. Electronic supplementary material The online version of this article (doi:10.1186/s12863-015-0325-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Cara L Ruble
- Tailored Therapeutics, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, ᅟ.
| | - Ryan M Smith
- Tailored Therapeutics, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, ᅟ.
| | - John Calley
- Tailored Therapeutics, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, ᅟ.
| | - Leanne Munsie
- Tailored Therapeutics, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, ᅟ.
| | - David C Airey
- Tailored Therapeutics, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, ᅟ.
| | - Yuan Gao
- Lieber Institute for Brain Development, Baltimore, MD, ᅟ.
| | - Joo Heon Shin
- Lieber Institute for Brain Development, Baltimore, MD, ᅟ.
| | - Thomas M Hyde
- Lieber Institute for Brain Development, Baltimore, MD, ᅟ. .,Departments of Neurology, Psychiatry and Behavioral Sciences, John Hopkins University School of Medicine, Baltimore, MD, ᅟ.
| | | | - Daniel R Weinberger
- Lieber Institute for Brain Development, Baltimore, MD, ᅟ. .,Departments of Psychiatry, Neurology, Neuroscience, and the Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, ᅟ.
| | - Laura K Nisenbaum
- Tailored Therapeutics, Lilly Corporate Center, Eli Lilly and Company, Indianapolis, IN, ᅟ.
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Regan PM, Sariyer IK, Langford TD, Datta PK, Khalili K. Morphine-induced MOR-1X and ASF/SF2 Expressions Are Independent of Transcriptional Regulation: Implications for MOR-1X Signaling. J Cell Physiol 2015; 231:1542-53. [PMID: 26553431 DOI: 10.1002/jcp.25246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 10/05/2015] [Indexed: 01/13/2023]
Abstract
Recently, multiple μ-opioid receptor (MOR) isoforms have been identified that originate from a single gene, OPRM1; however, both their regulation and their functional significance are poorly characterized. The objectives of this study were to decipher, first, the regulation of alternatively spliced μ-opioid receptor isoforms and the spliceosome components that determine splicing specificity and, second, the signaling pathways utilized by particular isoforms both constitutively and following agonist binding. Our studies demonstrated that the expression of a particular splice variant, MOR-1X, was up-regulated by morphine, and this coincided with an increase in the essential splicing factor ASF/SF2. Structural comparison of this isoform to the prototypical variant MOR-1 revealed that the unique distal portion of the C-terminal domain contains additional phosphorylation sites, whereas functional comparison found distinct signaling differences, particularly in the ERK and p90 RSK pathways. Additionally, MOR-1X expression significantly reduced Bax expression and mitochondrial dehydrogenase activity, suggesting a unique functional consequence for MOR-1X specific signaling. Collectively, these findings suggest that alternative splicing of the MOR is altered by exogenous opioids, such as morphine, and that individual isoforms, such as MOR-1X, mediate unique signal transduction with distinct functional consequence. Furthermore, we have identified for the first time a potential mechanism that involves the essential splicing factor ASF/SF2 through which morphine regulates splicing specificity of the MOR encoding gene, OPRM1.
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Affiliation(s)
- Patrick M Regan
- Department of Neuroscience and Center for Neurovirology, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Ilker K Sariyer
- Department of Neuroscience and Center for Neurovirology, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - T Dianne Langford
- Department of Neuroscience and Center for Neurovirology, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Prasun K Datta
- Department of Neuroscience and Center for Neurovirology, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Kamel Khalili
- Department of Neuroscience and Center for Neurovirology, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
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Functional Characterization of MC1R-TUBB3 Intergenic Splice Variants of the Human Melanocortin 1 Receptor. PLoS One 2015; 10:e0144757. [PMID: 26657157 PMCID: PMC4676704 DOI: 10.1371/journal.pone.0144757] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/23/2015] [Indexed: 12/29/2022] Open
Abstract
The melanocortin 1 receptor gene (MC1R) expressed in melanocytes is a major determinant of skin pigmentation. It encodes a Gs protein-coupled receptor activated by α-melanocyte stimulating hormone (αMSH). Human MC1R has an inefficient poly(A) site allowing intergenic splicing with its downstream neighbour Tubulin-β-III (TUBB3). Intergenic splicing produces two MC1R isoforms, designated Iso1 and Iso2, bearing the complete seven transmembrane helices from MC1R fused to TUBB3-derived C-terminal extensions, in-frame for Iso1 and out-of-frame for Iso2. It has been reported that exposure to ultraviolet radiation (UVR) might promote an isoform switch from canonical MC1R (MC1R-001) to the MC1R-TUBB3 chimeras, which might lead to novel phenotypes required for tanning. We expressed the Flag epitope-tagged intergenic isoforms in heterologous HEK293T cells and human melanoma cells, for functional characterization. Iso1 was expressed with the expected size. Iso2 yielded a doublet of Mr significantly lower than predicted, and impaired intracellular stability. Although Iso1- and Iso2 bound radiolabelled agonist with the same affinity as MC1R-001, their plasma membrane expression was strongly reduced. Decreased surface expression mostly resulted from aberrant forward trafficking, rather than high rates of endocytosis. Functional coupling of both isoforms to cAMP was lower than wild-type, but ERK activation upon binding of αMSH was unimpaired, suggesting imbalanced signaling from the splice variants. Heterodimerization of differentially labelled MC1R-001 with the splicing isoforms analyzed by co-immunoprecipitation was efficient and caused decreased surface expression of binding sites. Thus, UVR-induced MC1R isoforms might contribute to fine-tune the tanning response by modulating MC1R-001 availability and functional parameters.
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Wang X, Xu X, Lu X, Zhang Y, Pan W. Transcriptome Bioinformatical Analysis of Vertebrate Stages of Schistosoma japonicum Reveals Alternative Splicing Events. PLoS One 2015; 10:e0138470. [PMID: 26407301 PMCID: PMC4583307 DOI: 10.1371/journal.pone.0138470] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 08/31/2015] [Indexed: 01/22/2023] Open
Abstract
Alternative splicing is a molecular process that contributes greatly to the diversification of proteome and to gene functions. Understanding the mechanisms of stage-specific alternative splicing can provide a better understanding of the development of eukaryotes and the functions of different genes. Schistosoma japonicum is an infectious blood-dwelling trematode with a complex lifecycle that causes the tropical disease schistosomiasis. In this study, we analyzed the transcriptome of Schistosoma japonicum to discover alternative splicing events in this parasite, by applying RNA-seq to cDNA library of adults and schistosomula. Results were validated by RT-PCR and sequencing. We found 11,623 alternative splicing events among 7,099 protein encoding genes and average proportion of alternative splicing events per gene was 42.14%. We showed that exon skip is the most common type of alternative splicing events as found in high eukaryotes, whereas intron retention is the least common alternative splicing type. According to intron boundary analysis, the parasite possesses same intron boundaries as other organisms, namely the classic "GT-AG" rule. And in alternative spliced introns or exons, this rule is less strict. And we have attempted to detect alternative splicing events in genes encoding proteins with signal peptides and transmembrane helices, suggesting that alternative splicing could change subcellular locations of specific gene products. Our results indicate that alternative splicing is prevalent in this parasitic worm, and that the worm is close to its hosts. The revealed secretome involved in alternative splicing implies new perspective into understanding interaction between the parasite and its host.
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Affiliation(s)
- Xinye Wang
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
| | - Xindong Xu
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
| | - Xingyu Lu
- School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yuanbin Zhang
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
| | - Weiqing Pan
- Institute for Infectious Diseases and Vaccine Development, Tongji University School of Medicine, Shanghai, China
- Department of Tropical Infectious Diseases, Second Military Medical University, Shanghai, China
- * E-mail:
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Yan H, Jiang C, Li X, Sheng L, Dong Q, Peng X, Li Q, Zhao Y, Jiang H, Cheng B. PIGD: a database for intronless genes in the Poaceae. BMC Genomics 2014; 15:832. [PMID: 25270086 PMCID: PMC4195894 DOI: 10.1186/1471-2164-15-832] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 09/24/2014] [Indexed: 01/31/2023] Open
Abstract
Background Intronless genes are a feature of prokaryotes; however, they are widespread and unequally distributed among eukaryotes and represent an important resource to study the evolution of gene architecture. Although many databases on exons and introns exist, there is currently no cohesive database that collects intronless genes in plants into a single database. Description In this study, we present the Poaceae Intronless Genes Database (PIGD), a user-friendly web interface to explore information on intronless genes from different plants. Five Poaceae species, Sorghum bicolor, Zea mays, Setaria italica, Panicum virgatum and Brachypodium distachyon, are included in the current release of PIGD. Gene annotations and sequence data were collected and integrated from different databases. The primary focus of this study was to provide gene descriptions and gene product records. In addition, functional annotations, subcellular localization prediction and taxonomic distribution are reported. PIGD allows users to readily browse, search and download data. BLAST and comparative analyses are also provided through this online database, which is available at http://pigd.ahau.edu.cn/. Conclusion PIGD provides a solid platform for the collection, integration and analysis of intronless genes in the Poaceae. As such, this database will be useful for subsequent bio-computational analysis in comparative genomics and evolutionary studies.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Beijiu Cheng
- Key Laboratory of Crop Biology of Anhui Province, Anhui Agricultural University, Hefei 230036, China.
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Structured and disordered facets of the GPCR fold. Curr Opin Struct Biol 2014; 27:129-37. [PMID: 25198166 DOI: 10.1016/j.sbi.2014.08.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Revised: 07/28/2014] [Accepted: 08/05/2014] [Indexed: 01/14/2023]
Abstract
The seven-transmembrane (7TM) helix fold of G-protein coupled receptors (GPCRs) has been adapted for a wide variety of physiologically important signaling functions. Here, we discuss the diversity in the structured and disordered regions of GPCRs based on the recently published crystal structures and sequence analysis of all human GPCRs. A comparison of the structures of rhodopsin-like receptors (class A), secretin-like receptors (class B), metabotropic receptors (class C) and frizzled receptors (class F) shows that the relative arrangement of the transmembrane helices is conserved across all four GPCR classes although individual receptors can be activated by ligand binding at varying positions within and around the transmembrane helical bundle. A systematic analysis of GPCR sequences reveals the presence of disordered segments in the cytoplasmic side, abundant post-translational modification sites, evidence for alternative splicing and several putative linear peptide motifs that have the potential to mediate interactions with cytosolic proteins. While the structured regions permit the receptor to bind diverse ligands, the disordered regions appear to have an underappreciated role in modulating downstream signaling in response to the cellular state. An integrated paradigm combining the knowledge of structured and disordered regions is imperative for gaining a holistic understanding of the GPCR (un)structure-function relationship.
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Wnt signaling pathway pharmacogenetics in non-small cell lung cancer. THE PHARMACOGENOMICS JOURNAL 2014; 14:509-22. [PMID: 24980784 PMCID: PMC4237616 DOI: 10.1038/tpj.2014.21] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 04/02/2014] [Accepted: 04/15/2014] [Indexed: 12/27/2022]
Abstract
Wnt/β-catenin pathway alterations in non-small cell lung cancer (NSCLC) are associated with poor prognosis and resistance. In 598 stage III-IV NSCLC patients receiving platinum-based chemotherapy at MD Anderson Cancer Center (MDACC), we correlated survival with 441 host SNPs in 50 Wnt pathway genes. We then assessed the most significant SNPs in 240 Mayo Clinic patients receiving platinum-based chemotherapy for advanced NSCLC, 127 MDACC patients receiving platinum-based adjuvant chemotherapy and 340 early stage MDACC patients undergoing surgery alone (cohorts 2–4). In multivariate analysis, survival correlates with SNPs for AXIN2 (rs11868547 and rs4541111, of which rs11868547 was assessed in cohorts 2–4), Wnt-5B (rs12819505), CXXC4 (rs4413407) and WIF-1 (rs10878232). Median survival was 19.7, 15.6, and 10.7 months for patients with 1, 2, and 3–5 unfavorable genotypes, respectively (p= 3.8×10−9). Survival tree analysis classified patients into two groups (MST 11.3 vs 17.3 months, p=4.7×10−8). None of the SNPs achieved significance in cohorts 2–4; however, there was a trend in the same direction as cohort 1 for 3 of the SNPs. Using online databases, we found rs10878232 displayed expression quantitative trait loci (eQTL) correlation with the expression of LEMD3, a neighboring gene previously associated with NSCLC survival. In conclusion, results from cohort 1 provide further evidence for an important role for Wnt in NSCLC. Investigation of Wnt inhibitors in advanced NSCLC would be reasonable. Lack of a SNP association with outcome in cohorts 2–4 could be due to low statistical power, impact of patient heterogeneity, or false positive observations in cohort 1.
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García-Borrón JC, Abdel-Malek Z, Jiménez-Cervantes C. MC1R, the cAMP pathway, and the response to solar UV: extending the horizon beyond pigmentation. Pigment Cell Melanoma Res 2014; 27:699-720. [PMID: 24807163 DOI: 10.1111/pcmr.12257] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 05/01/2014] [Indexed: 12/20/2022]
Abstract
The melanocortin 1 receptor (MC1R) is a G protein-coupled receptor crucial for the regulation of melanocyte proliferation and function. Upon binding melanocortins, MC1R activates several signaling cascades, notably the cAMP pathway leading to synthesis of photoprotective eumelanin. Polymorphisms in the MC1R gene are a major source of normal variation of human hair color and skin pigmentation, response to ultraviolet radiation (UVR), and skin cancer susceptibility. The identification of a surprisingly high number of MC1R natural variants strongly associated with pigmentary phenotypes and increased skin cancer risk has prompted research on the functional properties of the wild-type receptor and frequent mutant alleles. We summarize current knowledge on MC1R structural and functional properties, as well as on its intracellular trafficking and signaling. We also review the current knowledge about the function of MC1R as a skin cancer, particularly melanoma, susceptibility gene and how it modulates the response of melanocytes to UVR.
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Affiliation(s)
- Jose C García-Borrón
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Murcia, Murcia, Spain; Instituto Murciano de Investigación Biomédica (IMIB), El Palmar, Murcia, Spain
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