1
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Zhang SS, Larrabee L, Chang AH, Desai S, Sloan L, Wang X, Wu Y, Parvez N, Amaratunga K, Hartman AC, Whitnall A, Mason J, Barton NP, Chu AY, Davitte JM, Csakai AJ, Tibbetts CV, Tolbert AE, O'Keefe H, Polanco J, Foley J, Kmett C, Kehler J, Kozejova G, Wang F, Mayer AP, Koenig P, Foletti D, Pitts SJ, Schnackenberg CG. Discovery of RXFP2 genetic association in resistant hypertensive men and RXFP2 antagonists for the treatment of resistant hypertension. Sci Rep 2024; 14:13209. [PMID: 38851835 PMCID: PMC11162469 DOI: 10.1038/s41598-024-62804-7] [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: 12/01/2023] [Accepted: 05/21/2024] [Indexed: 06/10/2024] Open
Abstract
Hypertension remains a leading cause of cardiovascular and kidney diseases. Failure to control blood pressure with ≥ 3 medications or control requiring ≥ 4 medications is classified as resistant hypertension (rHTN) and new therapies are needed to reduce the resulting increased risk of morbidity and mortality. Here, we report genetic evidence that relaxin family peptide receptor 2 (RXFP2) is associated with rHTN in men, but not in women. This study shows that adrenal gland gene expression of RXFP2 is increased in men with hypertension and the RXFP2 natural ligand, INSL3, increases adrenal steroidogenesis and corticosteroid secretion in human adrenal cells. To address the hypothesis that RXFP2 activation is an important mechanism in rHTN, we discovered and characterized small molecule and monoclonal antibody (mAb) blockers of RXFP2. The novel chemical entities and mAbs show potent, selective inhibition of RXFP2 and reduce aldosterone and cortisol synthesis and release. The RXFP2 mAbs have suitable rat pharmacokinetic profiles to evaluate the role of RXFP2 in the development and maintenance of rHTN. Overall, we identified RXFP2 activity as a potential new mechanism in rHTN and discovered RXFP2 antagonists for the future interrogation of RXFP2 in cardiovascular and renal diseases.
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Affiliation(s)
- Shan-Shan Zhang
- Therapeutics Division, 23andMe, 349 Oyster Point Blvd, South San Francisco, CA, 94080, USA
| | - Lance Larrabee
- Therapeutics Division, 23andMe, 349 Oyster Point Blvd, South San Francisco, CA, 94080, USA
| | - Andrew H Chang
- Therapeutics Division, 23andMe, 349 Oyster Point Blvd, South San Francisco, CA, 94080, USA
| | - Sapna Desai
- Medicinal Science and Technology, GSK, Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK
| | - Lisa Sloan
- Medicinal Science and Technology, GSK, Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK
| | - Xin Wang
- Research, 23andMe, 223 N Mathilda Ave., Sunnyvale, CA, 94086, USA
| | - Yixuan Wu
- Therapeutics Division, 23andMe, 349 Oyster Point Blvd, South San Francisco, CA, 94080, USA
| | - Nazia Parvez
- Medicinal Science and Technology, GSK, Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK
| | - Karen Amaratunga
- Medicinal Science and Technology, GSK, Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK
| | - Allison C Hartman
- Medicinal Science and Technology, GSK, 1250 S. Collegeville Rd., Collegeville, PA, 19426, USA
| | - Abby Whitnall
- Medicinal Science and Technology, GSK, Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK
| | - Joseph Mason
- Medicinal Science and Technology, GSK, Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK
| | - Nicholas P Barton
- Medicinal Science and Technology, GSK, Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK
| | - Audrey Y Chu
- Genomic Sciences, GSK, 300 Technology Square, Cambridge, MA, 02139, USA
| | | | - Adam J Csakai
- Medicinal Science and Technology, GSK, 200 Cambridgepark Drive, Cambridge, MA, 02140, USA
| | | | - Audrey E Tolbert
- Medicinal Science and Technology, GSK, 200 Cambridgepark Drive, Cambridge, MA, 02140, USA
| | - Heather O'Keefe
- Medicinal Science and Technology, GSK, 200 Cambridgepark Drive, Cambridge, MA, 02140, USA
| | - Jessie Polanco
- Therapeutics Division, 23andMe, 349 Oyster Point Blvd, South San Francisco, CA, 94080, USA
| | - Joseph Foley
- Novel Human Genetics Research Unit, GSK, 1250 S. Collegeville Rd., Collegeville, PA, 19426, USA
| | - Casey Kmett
- DMPK, GSK, 1250 S. Collegeville Rd, Collegeville, PA, 19426, USA
| | - Jonathan Kehler
- Bioanalysis, Immunogenicity and Biomarkers, GSK, 1250 S. Collegeville Rd., Collegeville, PA, 19426, USA
| | - Gabriela Kozejova
- Medicinal Science and Technology, GSK, Medicines Research Centre, Gunnels Wood Road, Stevenage, SG1 2NY, UK
| | - Feng Wang
- DMPK, GSK, 1250 S. Collegeville Rd, Collegeville, PA, 19426, USA
| | - Andrew P Mayer
- Bioanalysis, Immunogenicity and Biomarkers, GSK, 1250 S. Collegeville Rd., Collegeville, PA, 19426, USA
| | - Patrick Koenig
- Therapeutics Division, 23andMe, 349 Oyster Point Blvd, South San Francisco, CA, 94080, USA
| | - Davide Foletti
- Therapeutics Division, 23andMe, 349 Oyster Point Blvd, South San Francisco, CA, 94080, USA
| | - Steven J Pitts
- Research, 23andMe, 223 N Mathilda Ave., Sunnyvale, CA, 94086, USA
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2
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Structural Insights into the Unique Modes of Relaxin-Binding and Tethered-Agonist Mediated Activation of RXFP1 and RXFP2. J Mol Biol 2021; 433:167217. [PMID: 34454945 DOI: 10.1016/j.jmb.2021.167217] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/09/2021] [Accepted: 08/19/2021] [Indexed: 01/01/2023]
Abstract
Our poor understanding of the mechanism by which the peptide-hormone H2 relaxin activates its G protein coupled receptor, RXFP1 and the related receptor RXFP2, has hindered progress in its therapeutic development. Both receptors possess large ectodomains, which bind H2 relaxin, and contain an N-terminal LDLa module that is essential for receptor signaling and postulated to be a tethered agonist. Here, we show that a conserved motif (GDxxGWxxxF), C-terminal to the LDLa module, is critical for receptor activity. Importantly, this motif adopts different structures in RXFP1 and RXFP2, suggesting distinct activation mechanisms. For RXFP1, the motif is flexible, weakly associates with the LDLa module, and requires H2 relaxin binding to stabilize an active conformation. Conversely, the GDxxGWxxxF motif in RXFP2 is more closely associated with the LDLa module, forming an essential binding interface for H2 relaxin. These differences in the activation mechanism will aid drug development targeting these receptors.
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3
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Suteau V, Briet C, Lebeault M, Gourdin L, Henrion D, Rodien P, Munier M. Human amniotic fluid-based exposure levels of phthalates and bisphenol A mixture reduce INSL3/RXFP2 signaling. ENVIRONMENT INTERNATIONAL 2020; 138:105585. [PMID: 32126385 DOI: 10.1016/j.envint.2020.105585] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 01/22/2020] [Accepted: 02/14/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND The presence of chemical pollutants in the environment can affect human health. Epidemiological and in vivo experimental studies reveal reprotoxic effects (undescended testis) of phthalates (diethylhexyl phthalate (DEHP), dibutyl phthalate (DBP)) and bisphenol A (BPA), resulting in particular of a decrease in INSL3 (Insulin-Like 3 peptide) production. This hormone is essential for normal testis development and acts on a G protein-coupled receptor: RXFP2. OBJECTIVES The aim of this study was to evaluate the individual and combined impacts of DEHP, DBP, and BPA on human RXFP2 (hRXFP2) activity. METHODS We used HEK293 cells transiently transfected with hRXFP2 and receptor activity was analyzed by measuring intracellular cAMP production. The mixture was established at concentrations reported in human amniotic fluid, for the three compounds. RESULTS Individually, DEHP, DBP and BPA increased the response to INSL3 by 19.3 to 27.5%. This potentiating effect was specific for RXFP2, because it was absent in the cells which did not express this receptor. On the other hand, and interestingly, the mixture of the three compounds reduced significantly the response to INSL3 by 12%, and the observed effects were opposite to those predicted, suggesting an antagonist effect. DISCUSSION-CONCLUSION Taken together, our results demonstrate for the first time that a mixture of phthalates and BPA present in human amniotic fluid disturbs the human RXFP2 function. Moreover, we demonstrate that mixture can produce potential antagonistic effects that are not displayed by the compounds, individually.
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Affiliation(s)
- Valentine Suteau
- UMR CNRS 6015, INSERM 1083, MITOVASC Institute, 3 rue Roger Amsler, 49000 Angers, France; Department of Endocrinology, University Hospital, 4 rue Larrey, 49933 Angers, France.
| | - Claire Briet
- UMR CNRS 6015, INSERM 1083, MITOVASC Institute, 3 rue Roger Amsler, 49000 Angers, France; Department of Endocrinology, University Hospital, 4 rue Larrey, 49933 Angers, France; Reference Center for Rare Diseases of Thyroid and Hormone Receptors, University Hospital, 4 rue Larrey, 49933 Angers, France.
| | - Maÿlis Lebeault
- UMR CNRS 6015, INSERM 1083, MITOVASC Institute, 3 rue Roger Amsler, 49000 Angers, France; Department of Endocrinology, University Hospital, 4 rue Larrey, 49933 Angers, France.
| | - Louis Gourdin
- UMR CNRS 6015, INSERM 1083, MITOVASC Institute, 3 rue Roger Amsler, 49000 Angers, France; Reference Center for Rare Diseases of Thyroid and Hormone Receptors, University Hospital, 4 rue Larrey, 49933 Angers, France.
| | - Daniel Henrion
- UMR CNRS 6015, INSERM 1083, MITOVASC Institute, 3 rue Roger Amsler, 49000 Angers, France.
| | - Patrice Rodien
- UMR CNRS 6015, INSERM 1083, MITOVASC Institute, 3 rue Roger Amsler, 49000 Angers, France; Department of Endocrinology, University Hospital, 4 rue Larrey, 49933 Angers, France; Reference Center for Rare Diseases of Thyroid and Hormone Receptors, University Hospital, 4 rue Larrey, 49933 Angers, France.
| | - Mathilde Munier
- UMR CNRS 6015, INSERM 1083, MITOVASC Institute, 3 rue Roger Amsler, 49000 Angers, France; Department of Endocrinology, University Hospital, 4 rue Larrey, 49933 Angers, France; Reference Center for Rare Diseases of Thyroid and Hormone Receptors, University Hospital, 4 rue Larrey, 49933 Angers, France.
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Wang JH, Nie WH, Shao XX, Li HZ, Hu MJ, Liu YL, Xu ZG, Guo ZY. Exploring electrostatic interactions of relaxin family peptide receptor 3 and 4 with ligands using a NanoBiT-based binding assay. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:776-786. [DOI: 10.1016/j.bbamem.2019.01.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/16/2019] [Accepted: 01/21/2019] [Indexed: 12/15/2022]
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5
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Bathgate RA, Kocan M, Scott DJ, Hossain MA, Good SV, Yegorov S, Bogerd J, Gooley PR. The relaxin receptor as a therapeutic target – perspectives from evolution and drug targeting. Pharmacol Ther 2018; 187:114-132. [DOI: 10.1016/j.pharmthera.2018.02.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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6
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Distinct activation modes of the Relaxin Family Peptide Receptor 2 in response to insulin-like peptide 3 and relaxin. Sci Rep 2017; 7:3294. [PMID: 28607406 PMCID: PMC5468325 DOI: 10.1038/s41598-017-03638-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/02/2017] [Indexed: 11/16/2022] Open
Abstract
Relaxin family peptide receptor 2 (RXFP2) is a GPCR known for its role in reproductive function. It is structurally related to the human relaxin receptor RXFP1 and can be activated by human gene-2 (H2) relaxin as well as its cognate ligand insulin-like peptide 3 (INSL3). Both receptors possess an N-terminal low-density lipoprotein type a (LDLa) module that is necessary for activation and is joined to a leucine-rich repeat domain by a linker. This linker has been shown to be important for H2 relaxin binding and activation of RXFP1 and herein we investigate the role of the equivalent region of RXFP2. We demonstrate that the linker’s highly-conserved N-terminal region is essential for activation of RXFP2 in response to both ligands. In contrast, the linker is necessary for H2 relaxin, but not INSL3, binding. Our results highlight the distinct mechanism by which INSL3 activates RXFP2 whereby ligand binding mediates reorientation of the LDLa module by the linker region to activate the RXFP2 transmembrane domains in conjunction with the INSL3 A-chain. In contrast, relaxin activation of RXFP2 involves a more RXFP1-like mechanism involving binding to the LDLa-linker, reorientation of the LDLa module and activation of the transmembrane domains by the LDLa alone.
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7
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Wei D, Hu MJ, Shao XX, Wang JH, Nie WH, Liu YL, Xu ZG, Guo ZY. Development of a selective agonist for relaxin family peptide receptor 3. Sci Rep 2017; 7:3230. [PMID: 28607363 PMCID: PMC5468247 DOI: 10.1038/s41598-017-03465-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 04/27/2017] [Indexed: 12/01/2022] Open
Abstract
Relaxin family peptides perform a variety of biological functions by activating four G protein-coupled receptors, namely RXFP1–4. Among these receptors, RXFP3 lacks a specific natural or synthetic agonist at present. A previously designed chimeric R3/I5 peptide, consisting of the B-chain of relaxin-3 and the A-chain of INSL5, displays equal activity towards the homologous RXFP3 and RXFP4. To increase its selectivity towards RXFP3, in the present study we conducted extensive mutagenesis around the B-chain C-terminal region of R3/I5. Decreasing or increasing the peptide length around the B23–B25 position dramatically lowered the activation potency of R3/I5 towards both RXFP3 and RXFP4. Substitution of B23Gly with Ala or Ser converted R3/I5 from an efficient agonist to a strong antagonist for RXFP3, but the mutants retained considerable activation potency towards RXFP4. Substitution of B24Gly increased the selectivity of R3/I5 towards RXFP3 over the homologous RXFP4. The best mutant, [G(B24)S]R3/I5, displayed 20-fold higher activation potency towards RXFP3 than towards RXFP4, meanwhile retained full activation potency at RXFP3. Thus, [G(B24)S]R3/I5 is the best RXFP3-selective agonist known to date. It is a valuable tool for investigating the physiological functions of RXFP3, and also a suitable template for developing RXFP3-specific agonists in future.
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Affiliation(s)
- Dian Wei
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Meng-Jun Hu
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jia-Hui Wang
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Wei-Han Nie
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China.
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8
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Hu MJ, Shao XX, Wang JH, Wei D, Guo YQ, Liu YL, Xu ZG, Guo ZY. Mechanism for insulin-like peptide 5 distinguishing the homologous relaxin family peptide receptor 3 and 4. Sci Rep 2016; 6:29648. [PMID: 27404393 PMCID: PMC4939597 DOI: 10.1038/srep29648] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 06/07/2016] [Indexed: 12/11/2022] Open
Abstract
The relaxin family peptides play a variety of biological functions by activating four G protein-coupled receptors, RXFP1-4. Among them, insulin-like peptide 5 (INSL5) and relaxin-3 share the highest sequence homology, but they have distinct receptor preference: INSL5 can activate RXFP4 only, while relaxin-3 can activate RXFP3, RXFP4, and RXFP1. Previous studies suggest that the A-chain is responsible for their different selectivity for RXFP1. However, the mechanism by which INSL5 distinguishes the homologous RXFP4 and RXFP3 remains unknown. In the present work, we chemically evolved INSL5 in vitro to a strong agonist of both RXFP4 and RXFP3 through replacement of its five B-chain residues with the corresponding residues of relaxin-3. We identified four determinants (B2Glu, B9Leu, B17Tyr, and a rigid B-chain C-terminus) on INSL5 that are responsible for its inactivity at RXFP3. In reverse experiments, we grafted these determinants onto a chimeric R3/I5 peptide, which contains the B-chain of relaxin-3 and the A-chain of INSL5, and retains full activation potency at RXFP3 and RXFP4. All resultant R3/I5 mutants retained high activation potency towards RXFP4, but most displayed significantly decreased or even abolished activation potency towards RXFP3, confirming the role of these four INSL5 determinants in distinguishing RXFP4 from RXFP3.
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Affiliation(s)
- Meng-Jun Hu
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jia-Hui Wang
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Dian Wei
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Yu-Qi Guo
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Centre for Translational Medicine at East Hospital, College of Life Sciences and Technology, Tongji University, Shanghai, China
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9
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Tailhades J, Sethi A, Petrie EJ, Gooley PR, Bathgate RA, Wade JD, Hossain MA. Native Chemical Ligation to Minimize Aspartimide Formation during Chemical Synthesis of Small LDLa Protein. Chemistry 2015; 22:1146-51. [PMID: 26612092 DOI: 10.1002/chem.201503599] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Indexed: 12/21/2022]
Abstract
The inhibition of the G protein-coupled receptor, relaxin family peptide receptor 1 (RXFP1), by a small LDLa protein may be a potential approach for prostate cancer treatment. However, it is a significant challenge to chemically produce the 41-residue and three-disulfide cross-bridged LDLa module which is highly prone to aspartimide formation due to the presence of several aspartic acid residues. Known palliative measures, including addition of HOBt to piperidine for N(α) -deprotection, failed to completely overcome this side reaction. For this reason, an elegant native chemical ligation approach was employed in which two segments were assembled for generating the linear LDLa protein. Acquisition of correct folding was achieved by using either a regioselective disulfide bond formation or global oxidation strategies. The final synthetic LDLa protein obtained was characterized by NMR spectroscopic structural analysis after chelation with a Ca(2+) ion and confirmed to be equivalent to the same protein obtained by recombinant DNA production.
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Affiliation(s)
- Julien Tailhades
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, 3010, Australia.
| | - Ashish Sethi
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
| | - Emma J Petrie
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
| | - Paul R Gooley
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
| | - Ross A Bathgate
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, 3010, Australia.,Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
| | - John D Wade
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, 3010, Australia. .,The School of Chemistry, The University of Melbourne, Victoria, 3010, Australia.
| | - Mohammed A Hossain
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, 3010, Australia. .,The School of Chemistry, The University of Melbourne, Victoria, 3010, Australia.
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10
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Petrie EJ, Lagaida S, Sethi A, Bathgate RAD, Gooley PR. In a Class of Their Own - RXFP1 and RXFP2 are Unique Members of the LGR Family. Front Endocrinol (Lausanne) 2015; 6:137. [PMID: 26441827 PMCID: PMC4561518 DOI: 10.3389/fendo.2015.00137] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 08/20/2015] [Indexed: 01/12/2023] Open
Abstract
The leucine-rich repeat-containing G protein-coupled receptors (LGRs) family consists of three groups: types A, B, and C and all contain a large extracellular domain (ECD) made up of the structural motif - the leucine-rich repeat (LRR). In the LGRs, the ECD binds the hormone or ligand, usually through the LRRs, that ultimately results in activation and signaling. Structures are available for the ECD of type A and B LGRs, but not the type C LGRs. This review discusses the structural features of LRR proteins, and describes the known structures of the type A and B LGRs and predictions that can be made for the type C LGRs. The mechanism of activation of the LGRs is discussed with a focus on the role of the low-density lipoprotein class A (LDLa) module, a unique feature of the type C LGRs. While the LDLa module is essential for activation of the type C LGRs, the molecular mechanism for this process is unknown. Experimental data for the potential interactions of the type C LGR ligands with the LRR domain, the transmembrane domain, and the LDLa module are summarized.
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Affiliation(s)
- Emma J. Petrie
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
| | - Samantha Lagaida
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
| | - Ashish Sethi
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
| | - Ross A. D. Bathgate
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, Australia
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC, Australia
| | - Paul R. Gooley
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, VIC, Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, VIC, Australia
- *Correspondence: Paul R. Gooley, Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, VIC 3010, Australia,
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11
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Diepenhorst NA, Petrie EJ, Chen CZ, Wang A, Hossain MA, Bathgate RAD, Gooley PR. Investigation of interactions at the extracellular loops of the relaxin family peptide receptor 1 (RXFP1). J Biol Chem 2014; 289:34938-52. [PMID: 25352603 DOI: 10.1074/jbc.m114.600882] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Relaxin, an emerging pharmaceutical treatment for acute heart failure, activates the relaxin family peptide receptor (RXFP1), which is a class A G-protein-coupled receptor. In addition to the classic transmembrane (TM) domain, RXFP1 possesses a large extracellular domain consisting of 10 leucine-rich repeats and an N-terminal low density lipoprotein class A (LDLa) module. Relaxin-mediated activation of RXFP1 requires multiple coordinated interactions between the ligand and various receptor domains including a high affinity interaction involving the leucine-rich repeats and a predicted lower affinity interaction involving the extracellular loops (ELs). The LDLa is essential for signal activation; therefore the ELs/TM may additionally present an interaction site to facilitate this LDLa-mediated signaling. To overcome the many challenges of investigating relaxin and the LDLa module interactions with the ELs, we engineered the EL1 and EL2 loops onto a soluble protein scaffold, mapping specific ligand and loop interactions using nuclear magnetic resonance spectroscopy. Key EL residues were subsequently mutated in RXFP1, and changes in function and relaxin binding were assessed alongside the RXFP1 agonist ML290 to monitor the functional integrity of the TM domain of these mutant receptors. The outcomes of this work make an important contribution to understanding the mechanism of RXFP1 activation and will aid future development of small molecule RXFP1 agonists/antagonists.
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Affiliation(s)
- Natalie A Diepenhorst
- From the Florey Institute of Neuroscience and Mental Health, the Department of Biochemistry and Molecular Biology, and
| | - Emma J Petrie
- the Department of Biochemistry and Molecular Biology, and
| | - Catherine Z Chen
- the National Center for Advancing Translational Sciences, Division of Preclinical Innovation, National Institutes of Health, Rockville, Maryland 20850
| | - Amy Wang
- the National Center for Advancing Translational Sciences, Division of Preclinical Innovation, National Institutes of Health, Rockville, Maryland 20850
| | - Mohammed Akhter Hossain
- From the Florey Institute of Neuroscience and Mental Health, the School of Chemistry, University of Melbourne, Parkville, Victoria 3010, Australia and
| | - Ross A D Bathgate
- From the Florey Institute of Neuroscience and Mental Health, the Department of Biochemistry and Molecular Biology, and
| | - Paul R Gooley
- the Department of Biochemistry and Molecular Biology, and
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