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Sarson-Lawrence KTG, Hardy JM, Iaria J, Stockwell D, Behrens K, Saiyed T, Tan C, Jebeli L, Scott NE, Dite TA, Nicola NA, Leis AP, Babon JJ, Kershaw NJ. Cryo-EM structure of the extracellular domain of murine Thrombopoietin Receptor in complex with Thrombopoietin. Nat Commun 2024; 15:1135. [PMID: 38326297 PMCID: PMC10850085 DOI: 10.1038/s41467-024-45356-2] [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: 09/01/2023] [Accepted: 01/19/2024] [Indexed: 02/09/2024] Open
Abstract
Thrombopoietin (Tpo) is the primary regulator of megakaryocyte and platelet numbers and is required for haematopoetic stem cell maintenance. Tpo functions by binding its receptor (TpoR, a homodimeric Class I cytokine receptor) and initiating cell proliferation or differentiation. Here we characterise the murine Tpo:TpoR signalling complex biochemically and structurally, using cryo-electron microscopy. Tpo uses opposing surfaces to recruit two copies of receptor, forming a 1:2 complex. Although it binds to the same, membrane-distal site on both receptor chains, it does so with significantly different affinities and its highly glycosylated C-terminal domain is not required. In one receptor chain, a large insertion, unique to TpoR, forms a partially structured loop that contacts cytokine. Tpo binding induces the juxtaposition of the two receptor chains adjacent to the cell membrane. The therapeutic agent romiplostim also targets the cytokine-binding site and the characterisation presented here supports the future development of improved TpoR agonists.
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Affiliation(s)
- Kaiseal T G Sarson-Lawrence
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Joshua M Hardy
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
| | - Josephine Iaria
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Dina Stockwell
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Kira Behrens
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Tamanna Saiyed
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Cyrus Tan
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Leila Jebeli
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, 3000, Victoria, Australia
| | - Nichollas E Scott
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, 3000, Victoria, Australia
| | - Toby A Dite
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Nicos A Nicola
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Andrew P Leis
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
| | - Jeffrey J Babon
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia.
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia.
| | - Nadia J Kershaw
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia.
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia.
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2
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Stefanucci L, Collins J, Sims MC, Barrio-Hernandez I, Sun L, Burren OS, Perfetto L, Bender I, Callahan TJ, Fleming K, Guerrero JA, Hermjakob H, Martin MJ, Stephenson J, Paneerselvam K, Petrovski S, Porras P, Robinson PN, Wang Q, Watkins X, Frontini M, Laskowski RA, Beltrao P, Di Angelantonio E, Gomez K, Laffan M, Ouwehand WH, Mumford AD, Freson K, Carss K, Downes K, Gleadall N, Megy K, Bruford E, Vuckovic D. The effects of pathogenic and likely pathogenic variants for inherited hemostasis disorders in 140 214 UK Biobank participants. Blood 2023; 142:2055-2068. [PMID: 37647632 PMCID: PMC10733830 DOI: 10.1182/blood.2023020118] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 08/04/2023] [Accepted: 08/04/2023] [Indexed: 09/01/2023] Open
Abstract
Rare genetic diseases affect millions, and identifying causal DNA variants is essential for patient care. Therefore, it is imperative to estimate the effect of each independent variant and improve their pathogenicity classification. Our study of 140 214 unrelated UK Biobank (UKB) participants found that each of them carries a median of 7 variants previously reported as pathogenic or likely pathogenic. We focused on 967 diagnostic-grade gene (DGG) variants for rare bleeding, thrombotic, and platelet disorders (BTPDs) observed in 12 367 UKB participants. By association analysis, for a subset of these variants, we estimated effect sizes for platelet count and volume, and odds ratios for bleeding and thrombosis. Variants causal of some autosomal recessive platelet disorders revealed phenotypic consequences in carriers. Loss-of-function variants in MPL, which cause chronic amegakaryocytic thrombocytopenia if biallelic, were unexpectedly associated with increased platelet counts in carriers. We also demonstrated that common variants identified by genome-wide association studies (GWAS) for platelet count or thrombosis risk may influence the penetrance of rare variants in BTPD DGGs on their associated hemostasis disorders. Network-propagation analysis applied to an interactome of 18 410 nodes and 571 917 edges showed that GWAS variants with large effect sizes are enriched in DGGs and their first-order interactors. Finally, we illustrate the modifying effect of polygenic scores for platelet count and thrombosis risk on disease severity in participants carrying rare variants in TUBB1 or PROC and PROS1, respectively. Our findings demonstrate the power of association analyses using large population datasets in improving pathogenicity classifications of rare variants.
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Affiliation(s)
- Luca Stefanucci
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
- British Heart Foundation, BHF Centre of Research Excellence, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Janine Collins
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Haematology, Barts Health NHS Trust, London, United Kingdom
| | - Matthew C. Sims
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Haematology, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield, United Kingdom
- Department of Oncology and Metabolism, University of Sheffield, Sheffield, United Kingdom
| | - Inigo Barrio-Hernandez
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Luanluan Sun
- Department of Public Health and Primary Care, BHF Cardiovascular Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom
| | - Oliver S. Burren
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, United Kingdom
| | - Livia Perfetto
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, United Kingdom
- Department of Biology and Biotechnology “C.Darwin,” Sapienza University of Rome, Rome, Italy
| | - Isobel Bender
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Tiffany J. Callahan
- Department of Biomedical Informatics, Columbia University Irving Medical Center, New York, NY
| | - Kathryn Fleming
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - Jose A. Guerrero
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Haematology, Barts Health NHS Trust, London, United Kingdom
| | - Henning Hermjakob
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Maria J. Martin
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - James Stephenson
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - NIHR BioResource
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
- British Heart Foundation, BHF Centre of Research Excellence, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Haematology, Barts Health NHS Trust, London, United Kingdom
- Department of Haematology, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield, United Kingdom
- Department of Oncology and Metabolism, University of Sheffield, Sheffield, United Kingdom
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, United Kingdom
- Department of Public Health and Primary Care, BHF Cardiovascular Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, United Kingdom
- Department of Biology and Biotechnology “C.Darwin,” Sapienza University of Rome, Rome, Italy
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
- Department of Biomedical Informatics, Columbia University Irving Medical Center, New York, NY
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
- Centre for Genomics Research, Discovery Sciences, AstraZeneca, Cambridge, United Kingdom
- Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Australia
- Genomic Medicine, The Jackson Laboratory, Farmington, CT
- Institute for Systems Genomics, University of Connecticut, Farmington, CT
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences RILD Building, University of Exeter Medical School, Exeter, United Kingdom
- Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland
- Heart and Lung Research Institute, University of Cambridge, Cambridge, United Kingdom
- NIHR Blood and Transplant Research Unit in Donor Health and Behaviour, Cambridge, United Kingdom
- Health Data Research UK Cambridge, Wellcome Genome Campus and University of Cambridge, Cambridge, United Kingdom
- Health Data Science Centre, Human Technopole, Milan, Italy
- Haemophilia Centre and Thrombosis Unit, Royal Free London NHS Foundation Trust, London, United Kingdom
- Department of Haematology, Imperial College Healthcare NHS Trust, London, United Kingdom
- Department of Immunology and Inflammation, Centre for Haematology, Imperial College London, London, United Kingdom
- Department of Haematology, University College London Hospitals NHS Trust, London, United Kingdom
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KULeuven, Leuven, Belgium
- Cambridge Genomics Laboratory, Cambridge University Hospitals National Health Service Foundation Trust, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Epidemiology and Biostatistics, Imperial College London, London, United Kingdom
| | - Kalpana Paneerselvam
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Slavé Petrovski
- Centre for Genomics Research, Discovery Sciences, AstraZeneca, Cambridge, United Kingdom
- Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Australia
| | - Pablo Porras
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Peter N. Robinson
- Genomic Medicine, The Jackson Laboratory, Farmington, CT
- Institute for Systems Genomics, University of Connecticut, Farmington, CT
| | - Quanli Wang
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, United Kingdom
| | - Xavier Watkins
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Mattia Frontini
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
- British Heart Foundation, BHF Centre of Research Excellence, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences RILD Building, University of Exeter Medical School, Exeter, United Kingdom
| | - Roman A. Laskowski
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Pedro Beltrao
- Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland
| | - Emanuele Di Angelantonio
- British Heart Foundation, BHF Centre of Research Excellence, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Public Health and Primary Care, BHF Cardiovascular Epidemiology Unit, University of Cambridge, Cambridge, United Kingdom
- Heart and Lung Research Institute, University of Cambridge, Cambridge, United Kingdom
- NIHR Blood and Transplant Research Unit in Donor Health and Behaviour, Cambridge, United Kingdom
- Health Data Research UK Cambridge, Wellcome Genome Campus and University of Cambridge, Cambridge, United Kingdom
- Health Data Science Centre, Human Technopole, Milan, Italy
| | - Keith Gomez
- Haemophilia Centre and Thrombosis Unit, Royal Free London NHS Foundation Trust, London, United Kingdom
| | - Mike Laffan
- Department of Haematology, Imperial College Healthcare NHS Trust, London, United Kingdom
- Department of Immunology and Inflammation, Centre for Haematology, Imperial College London, London, United Kingdom
| | - Willem H. Ouwehand
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Haematology, University College London Hospitals NHS Trust, London, United Kingdom
| | - Andrew D. Mumford
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - Kathleen Freson
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KULeuven, Leuven, Belgium
| | - Keren Carss
- Centre for Genomics Research, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge, United Kingdom
| | - Kate Downes
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Cambridge Genomics Laboratory, Cambridge University Hospitals National Health Service Foundation Trust, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Nick Gleadall
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Karyn Megy
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Elspeth Bruford
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Dragana Vuckovic
- Department of Epidemiology and Biostatistics, Imperial College London, London, United Kingdom
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3
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Pogozheva ID, Cherepanov S, Park SJ, Raghavan M, Im W, Lomize AL. Structural Modeling of Cytokine-Receptor-JAK2 Signaling Complexes Using AlphaFold Multimer. J Chem Inf Model 2023; 63:5874-5895. [PMID: 37694948 DOI: 10.1021/acs.jcim.3c00926] [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] [Indexed: 09/12/2023]
Abstract
Homodimeric class 1 cytokine receptors include the erythropoietin (EPOR), thrombopoietin (TPOR), granulocyte colony-stimulating factor 3 (CSF3R), growth hormone (GHR), and prolactin receptors (PRLR). These cell-surface single-pass transmembrane (TM) glycoproteins regulate cell growth, proliferation, and differentiation and induce oncogenesis. An active TM signaling complex consists of a receptor homodimer, one or two ligands bound to the receptor extracellular domains, and two molecules of Janus Kinase 2 (JAK2) constitutively associated with the receptor intracellular domains. Although crystal structures of soluble extracellular domains with ligands have been obtained for all of the receptors except TPOR, little is known about the structure and dynamics of the complete TM complexes that activate the downstream JAK-STAT signaling pathway. Three-dimensional models of five human receptor complexes with cytokines and JAK2 were generated here by using AlphaFold Multimer. Given the large size of the complexes (from 3220 to 4074 residues), the modeling required a stepwise assembly from smaller parts, with selection and validation of the models through comparisons with published experimental data. The modeling of active and inactive complexes supports a general activation mechanism that involves ligand binding to a monomeric receptor followed by receptor dimerization and rotational movement of the receptor TM α-helices, causing proximity, dimerization, and activation of associated JAK2 subunits. The binding mode of two eltrombopag molecules to the TM α-helices of the active TPOR dimer was proposed. The models also help elucidate the molecular basis of oncogenic mutations that may involve a noncanonical activation route. Models equilibrated in explicit lipids of the plasma membrane are publicly available.
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Affiliation(s)
- Irina D Pogozheva
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Stanislav Cherepanov
- Biophysics Program, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Sang-Jun Park
- Departments of Biological Sciences and Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Malini Raghavan
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States
| | - Wonpil Im
- Departments of Biological Sciences and Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Andrei L Lomize
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
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4
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Pogozheva ID, Cherepanov S, Park SJ, Raghavan M, Im W, Lomize AL. Structural modeling of cytokine-receptor-JAK2 signaling complexes using AlphaFold Multimer. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.14.544971. [PMID: 37398331 PMCID: PMC10312770 DOI: 10.1101/2023.06.14.544971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Homodimeric class 1 cytokine receptors include the erythropoietin (EPOR), thrombopoietin (TPOR), granulocyte colony-stimulating factor 3 (CSF3R), growth hormone (GHR), and prolactin receptors (PRLR). They are cell-surface single-pass transmembrane (TM) glycoproteins that regulate cell growth, proliferation, and differentiation and induce oncogenesis. An active TM signaling complex consists of a receptor homodimer, one or two ligands bound to the receptor extracellular domains and two molecules of Janus Kinase 2 (JAK2) constitutively associated with the receptor intracellular domains. Although crystal structures of soluble extracellular domains with ligands have been obtained for all the receptors except TPOR, little is known about the structure and dynamics of the complete TM complexes that activate the downstream JAK-STAT signaling pathway. Three-dimensional models of five human receptor complexes with cytokines and JAK2 were generated using AlphaFold Multimer. Given the large size of the complexes (from 3220 to 4074 residues), the modeling required a stepwise assembly from smaller parts with selection and validation of the models through comparisons with published experimental data. The modeling of active and inactive complexes supports a general activation mechanism that involves ligand binding to a monomeric receptor followed by receptor dimerization and rotational movement of the receptor TM α-helices causing proximity, dimerization, and activation of associated JAK2 subunits. The binding mode of two eltrombopag molecules to TM α-helices of the active TPOR dimer was proposed. The models also help elucidating the molecular basis of oncogenic mutations that may involve non-canonical activation route. Models equilibrated in explicit lipids of the plasma membrane are publicly available.
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Affiliation(s)
- Irina D. Pogozheva
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, United States
| | | | - Sang-Jun Park
- Departments of Biological Sciences and Chemistry, Lehigh University, Bethlehem, PA 18015, United States
| | - Malini Raghavan
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109, United States
| | - Wonpil Im
- Departments of Biological Sciences and Chemistry, Lehigh University, Bethlehem, PA 18015, United States
| | - Andrei L. Lomize
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, United States
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5
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Desikan H, Kaur A, Pogozheva ID, Raghavan M. Effects of calreticulin mutations on cell transformation and immunity. J Cell Mol Med 2023; 27:1032-1044. [PMID: 36916035 PMCID: PMC10098294 DOI: 10.1111/jcmm.17713] [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: 11/04/2022] [Revised: 02/22/2023] [Accepted: 02/24/2023] [Indexed: 03/16/2023] Open
Abstract
Myeloproliferative neoplasms (MPNs) are cancers involving dysregulated production and function of myeloid lineage hematopoietic cells. Among MPNs, Essential thrombocythemia (ET), Polycythemia Vera (PV) and Myelofibrosis (MF), are driven by mutations that activate the JAK-STAT signalling pathway. Somatic mutations of calreticulin (CRT), an endoplasmic reticulum (ER)-localized lectin chaperone, are driver mutations in approximately 25% of ET and 35% of MF patients. The MPN-linked mutant CRT proteins have novel frameshifted carboxy-domain sequences and lack an ER retention motif, resulting in their secretion. Wild type CRT is a regulator of ER calcium homeostasis and plays a key role in the assembly of major histocompatibility complex (MHC) class I molecules, which are the ligands for antigen receptors of CD8+ T cells. Mutant CRT-linked oncogenesis results from the dysregulation of calcium signalling in cells and the formation of stable complexes of mutant CRT with myeloproliferative leukemia (MPL) protein, followed by downstream activation of the JAK-STAT signalling pathway. The intricate participation of CRT in ER protein folding, calcium homeostasis and immunity suggests the involvement of multiple mechanisms of mutant CRT-linked oncogenesis. In this review, we highlight recent findings related to the role of MPN-linked CRT mutations in the dysregulation of calcium homeostasis, MPL activation and immunity.
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Affiliation(s)
- Harini Desikan
- Department of Microbiology and ImmunologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
| | - Amanpreet Kaur
- Department of Microbiology and ImmunologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
| | - Irina D. Pogozheva
- Department of Medicinal ChemistryCollege of Pharmacy, University of MichiganAnn ArborMichiganUSA
| | - Malini Raghavan
- Department of Microbiology and ImmunologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
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Germeshausen M, Ballmaier M. CAMT-MPL: congenital amegakaryocytic thrombocytopenia caused by MPL mutations - heterogeneity of a monogenic disorder - a comprehensive analysis of 56 patients. Haematologica 2021; 106:2439-2448. [PMID: 32703794 PMCID: PMC8409039 DOI: 10.3324/haematol.2020.257972] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Indexed: 11/17/2022] Open
Abstract
Congenital amegakaryocytic thrombocytopenia caused by deleterious homozygous or compound heterozygous mutations in MPL (CAMT-MPL) is a rare inherited bone marrow failure syndrome presenting as an isolated thrombocytopenia at birth progressing to pancytopenia due to exhaustion of hematopoietic progenitors. The analysis of samples and clinical data from a large cohort of 56 patients with CAMT-MPL resulted in a detailed description of the clinical picture and reliable genotype-phenotype correlations for this rare disease. We extended the spectrum of CAMT causing MPL mutations regarding number (17 novel mutations) and impact. Clinical courses showed great variability with respect to the severity of thrombocytopenia, the development of pancytopenia and the consequences from bleedings. The most severe clinical problems were (i) intracranial bleedings pre- and perinatally and the resulting long-term consequences, and (ii) the development of aplastic anemia in the later course of the disease. An important and new finding was that thrombocytopenia was not detected at birth in a quarter of the patients. The rate of non-hematological abnormalities in CAMT-MPL was higher than described so far. Most of the anomalies were related to the head region (brain anomalies, ocular and orbital anomalies) and consequences of intracranial bleedings. The present study demonstrates a higher variability of clinical courses than described so far and has important implications on diagnosis and therapy. The diagnosis CAMT-MPL has to be considered even for those patients who are inconspicuous in the first months of life or show somatic anomalies typical for other inherited bone marrow failure syndromes.
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Affiliation(s)
- Manuela Germeshausen
- Central Research Facility Cell Sorting, Hannover Medical School, Hannover, Germany.
| | - Matthias Ballmaier
- Central Research Facility Cell Sorting, Hannover Medical School, Hannover, Germany.
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7
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Roy A, Shrivastva S, Naseer S. In and out: Traffic and dynamics of thrombopoietin receptor. J Cell Mol Med 2021; 25:9073-9083. [PMID: 34448528 PMCID: PMC8500957 DOI: 10.1111/jcmm.16878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/27/2021] [Accepted: 08/04/2021] [Indexed: 12/17/2022] Open
Abstract
Thrombopoiesis had long been a challenging area of study due to the rarity of megakaryocyte precursors in the bone marrow and the incomplete understanding of its regulatory cytokines. A breakthrough was achieved in the early 1990s with the discovery of the thrombopoietin receptor (TpoR) and its ligand thrombopoietin (TPO). This accelerated research in thrombopoiesis, including the uncovering of the molecular basis of myeloproliferative neoplasms (MPN) and the advent of drugs to treat thrombocytopenic purpura. TpoR mutations affecting its membrane dynamics or transport were increasingly associated with pathologies such as MPN and thrombocytosis. It also became apparent that TpoR affected hematopoietic stem cell (HSC) quiescence while priming hematopoietic stem cells (HSCs) towards the megakaryocyte lineage. Thorough knowledge of TpoR surface localization, dimerization, dynamics and stability is therefore crucial to understanding thrombopoiesis and related pathologies. In this review, we will discuss the mechanisms of TpoR traffic. We will focus on the recent progress in TpoR membrane dynamics and highlight the areas that remain unexplored.
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Affiliation(s)
- Anita Roy
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
| | - Saurabh Shrivastva
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
| | - Saadia Naseer
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
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8
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Bellanné-Chantelot C, Rabadan Moraes G, Schmaltz-Panneau B, Marty C, Vainchenker W, Plo I. Germline genetic factors in the pathogenesis of myeloproliferative neoplasms. Blood Rev 2020; 42:100710. [PMID: 32532454 DOI: 10.1016/j.blre.2020.100710] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 04/08/2020] [Accepted: 05/05/2020] [Indexed: 02/06/2023]
Abstract
Myeloproliferative neoplasms (MPN) are clonal hematological malignancies that lead to overproduction of mature myeloid cells. They are due to acquired mutations in genes encoding for AK2, MPL and CALR that result in the activation of the cytokine receptor/JAK2 signaling pathway. In addition, it exists germline variants that can favor the initiation of the disease or may affect its phenotype. First, they can be common risk alleles, which correspond to frequent single nucleotide variants present in control population and that contribute to the development of either sporadic or familial MPN. Second, some variants predispose to the onset of MPN with a higher penetrance and lead to familial clustering of MPN. Finally, some extremely rare genetic variants can induce MPN-like hereditary disease. We will review these different subtypes of germline genetic variants and discuss how they impact the initiation and/or development of the MPN disease.
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Affiliation(s)
- Christine Bellanné-Chantelot
- Department of Genetics, Assistance Publique-Hôpitaux de Paris (APHP), Hôpitaux Universitaires Pitié Salpêtrière-Charles Foix, Sorbonne Université, Paris, France; INSERM, UMR1287, Laboratory of Excellence GR-Ex, Villejuif, France
| | - Graciela Rabadan Moraes
- INSERM, UMR1287, Laboratory of Excellence GR-Ex, Villejuif, France; Université Paris Diderot (Paris 7), UMR1287, Gustave Roussy, Villejuif, France; Gustave Roussy, Villejuif, France
| | - Barbara Schmaltz-Panneau
- INSERM, UMR1287, Laboratory of Excellence GR-Ex, Villejuif, France; Gustave Roussy, Villejuif, France; Université Paris XI, UMR1287, Gustave Roussy, Villejuif, France
| | - Caroline Marty
- INSERM, UMR1287, Laboratory of Excellence GR-Ex, Villejuif, France; Gustave Roussy, Villejuif, France; Université Paris XI, UMR1287, Gustave Roussy, Villejuif, France
| | - William Vainchenker
- INSERM, UMR1287, Laboratory of Excellence GR-Ex, Villejuif, France; Gustave Roussy, Villejuif, France; Université Paris XI, UMR1287, Gustave Roussy, Villejuif, France
| | - Isabelle Plo
- INSERM, UMR1287, Laboratory of Excellence GR-Ex, Villejuif, France; Gustave Roussy, Villejuif, France; Université Paris XI, UMR1287, Gustave Roussy, Villejuif, France.
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9
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Congenital Amegakaryocytic Thrombocytopenia: A Case Series Indicating 2 Founder Variants in the Mississippi Band of Choctaw Indians. J Pediatr Hematol Oncol 2017; 39:573-575. [PMID: 28697167 DOI: 10.1097/mph.0000000000000904] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Congenital amegakaryocytic thrombocytopenia is a rare disorder causing thrombocytopenia that progresses to pancytopenia and bone marrow failure if untreated. It is caused by variants in the MPL gene which encodes the thrombopoeitin receptor. In this report, we review 5 cases of congenital amegakaryocytic thrombocytopenia, all of whom belong to the Mississippi Band of Choctaw Indians. There are 2 common variants in these cases: R90X and R537W. One variant was previously reported only once and had unclear significance at that time. With these variants identified, we hope to improve screening that results in earlier diagnosis in the Choctaw population in the future.
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10
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Gene editing rescue of a novel MPL mutant associated with congenital amegakaryocytic thrombocytopenia. Blood Adv 2017; 1:1815-1826. [PMID: 29296828 DOI: 10.1182/bloodadvances.2016002915] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 08/10/2017] [Indexed: 12/19/2022] Open
Abstract
Thrombopoietin (Tpo) and its receptor (Mpl) are the principal regulators of early and late thrombopoiesis and hematopoietic stem cell maintenance. Mutations in MPL can drastically impair its function and be a contributing factor in multiple hematologic malignancies, including congenital amegakaryocytic thrombocytopenia (CAMT). CAMT is characterized by severe thrombocytopenia at birth, which progresses to bone marrow failure and pancytopenia. Here we report unique familial cases of CAMT that presented with a previously unreported MPL mutation: T814C (W272R) in the background of the activating MPL G117T (K39N or Baltimore) mutation. Confocal microscopy, proliferation and surface biotinylation assays, co-immunoprecipitation, and western blotting analysis were used to elucidate the function and trafficking of Mpl mutants. Results showed that Mpl protein bearing the W272R mutation, alone or together with the K39N mutation, lacks detectable surface expression while being strongly colocalized with the endoplasmic reticulum (ER) marker calreticulin. Both WT and K39N-mutated Mpl were found to be signaling competent, but single or double mutants bearing W272R were unresponsive to Tpo. Function of the deficient Mpl receptor could be rescued by using 2 separate approaches: (1) GRASP55 overexpression, which partially restored Tpo-induced signaling of mutant Mpl by activating an autophagy-dependent secretory pathway and thus forcing ER-trapped immature receptors to traffic to the cell surface; and (2) CRISPR-Cas9 gene editing used to repair MPL T814C mutation in transfected cell lines and primary umbilical cord blood-derived CD34+ cells. We demonstrate proof of principle for rescue of mutant Mpl function by using gene editing of primary hematopoietic stem cells, which indicates direct therapeutic applications for CAMT patients.
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11
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Bellanné-Chantelot C, Mosca M, Marty C, Favier R, Vainchenker W, Plo I. Identification of MPL R102P Mutation in Hereditary Thrombocytosis. Front Endocrinol (Lausanne) 2017; 8:235. [PMID: 28979237 PMCID: PMC5611484 DOI: 10.3389/fendo.2017.00235] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 08/28/2017] [Indexed: 01/11/2023] Open
Abstract
The molecular basis of hereditary thrombocytosis is germline mutations affecting the thrombopoietin (TPO)/TPO receptor (MPL)/JAK2 signaling axis. Here, we report one family presenting two cases with a mild thrombocytosis. By sequencing JAK2 and MPL coding exons, we identified a germline MPL R102P heterozygous mutation in the proband and his daughter. Concomitantly, we detected high TPO levels in the serum of these two patients. The mutation was not found in three other unaffected cases from the family except in another proband's daughter who did not present thrombocytosis but had a high TPO level. The MPL R102P mutation was first described in congenital amegakaryocytic thrombocytopenia in a homozygous state with a loss-of-function activity. It was previously shown that MPL R102P was blocked in the endoplasmic reticulum without being able to translocate to the plasma membrane. Thus, this case report identifies for the first time that MPL R102P mutation can differently impact megakaryopoiesis: thrombocytosis or thrombocytopenia depending on the presence of the heterozygous or homozygous state, respectively. The paradoxical effect associated with heterozygous MPL R102P may be due to subnormal cell-surface expression of wild-type MPL in platelets inducing a defective TPO clearance. As a consequence, increased TPO levels may activate megakaryocyte progenitors that express a lower, but still sufficient level of MPL for the induction of proliferation.
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Affiliation(s)
- Christine Bellanné-Chantelot
- INSERM UMR1170, Gustave Roussy, Villejuif, France
- Department of Genetics, Assistance Publique-Hôpitaux de Paris (AP-HP) Hôpitaux Universitaires Pitié Salpêtrière—Charles Foix, UPMC Univ Paris 06, Paris, France
| | - Matthieu Mosca
- INSERM UMR1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
| | - Caroline Marty
- INSERM UMR1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
| | - Rémi Favier
- INSERM UMR1170, Gustave Roussy, Villejuif, France
- Assistance Publique-Hôpitaux de Paris (AP-HP), Service d’Hématologie biologique, Centre de Référence des Pathologies Plaquettaires (CRPP), Hôpital Armand Trousseau, Paris, France
| | - William Vainchenker
- INSERM UMR1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
| | - Isabelle Plo
- INSERM UMR1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
- *Correspondence: Isabelle Plo,
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12
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Varghese LN, Defour JP, Pecquet C, Constantinescu SN. The Thrombopoietin Receptor: Structural Basis of Traffic and Activation by Ligand, Mutations, Agonists, and Mutated Calreticulin. Front Endocrinol (Lausanne) 2017; 8:59. [PMID: 28408900 PMCID: PMC5374145 DOI: 10.3389/fendo.2017.00059] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 03/17/2017] [Indexed: 12/13/2022] Open
Abstract
A well-functioning hematopoietic system requires a certain robustness and flexibility to maintain appropriate quantities of functional mature blood cells, such as red blood cells and platelets. This review focuses on the cytokine receptor that plays a significant role in thrombopoiesis: the receptor for thrombopoietin (TPO-R; also known as MPL). Here, we survey the work to date to understand how this receptor functions at a molecular level throughout its lifecycle, from traffic to the cell surface, dimerization and binding cognate cytokine via its extracellular domain, through to its subsequent activation of associated Janus kinases and initiation of downstream signaling pathways, as well as the regulation of these processes. Atomic level resolution structures of TPO-R have remained elusive. The identification of disease-causing mutations in the receptor has, however, offered some insight into structure and function relationships, as has artificial means of receptor activation, through TPO mimetics, transmembrane-targeting receptor agonists, and engineering in dimerization domains. More recently, a novel activation mechanism was identified whereby mutated forms of calreticulin form complexes with TPO-R via its extracellular N-glycosylated domain. Such complexes traffic pathologically in the cell and persistently activate JAK2, downstream signal transducers and activators of transcription (STATs), and other pathways. This pathologic TPO-R activation is associated with a large fraction of human myeloproliferative neoplasms.
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Affiliation(s)
- Leila N. Varghese
- Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium
- SIGN Pole, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Jean-Philippe Defour
- Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium
- SIGN Pole, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
- Department of Clinical Biology, Cliniques universitaires St Luc, Université catholique de Louvain, Brussels, Belgium
| | - Christian Pecquet
- Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium
- SIGN Pole, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Stefan N. Constantinescu
- Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium
- SIGN Pole, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
- *Correspondence: Stefan N. Constantinescu,
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13
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Plo I, Bellanné-Chantelot C, Mosca M, Mazzi S, Marty C, Vainchenker W. Genetic Alterations of the Thrombopoietin/MPL/JAK2 Axis Impacting Megakaryopoiesis. Front Endocrinol (Lausanne) 2017; 8:234. [PMID: 28955303 PMCID: PMC5600916 DOI: 10.3389/fendo.2017.00234] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/28/2017] [Indexed: 12/31/2022] Open
Abstract
Megakaryopoiesis is an original and complex cell process which leads to the formation of platelets. The homeostatic production of platelets is mainly regulated and controlled by thrombopoietin (TPO) and the TPO receptor (MPL)/JAK2 axis. Therefore, any hereditary or acquired abnormality affecting this signaling axis can result in thrombocytosis or thrombocytopenia. Thrombocytosis can be due to genetic alterations that affect either the intrinsic MPL signaling through gain-of-function (GOF) activity (MPL, JAK2, CALR) and loss-of-function (LOF) activity of negative regulators (CBL, LNK) or the extrinsic MPL signaling by THPO GOF mutations leading to increased TPO synthesis. Alternatively, thrombocytosis may paradoxically result from mutations of MPL leading to an abnormal MPL trafficking, inducing increased TPO levels by alteration of its clearance. In contrast, thrombocytopenia can also result from LOF THPO or MPL mutations, which cause a complete defect in MPL trafficking to the cell membrane, impaired MPL signaling or stability, defects in the TPO/MPL interaction, or an absence of TPO production.
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Affiliation(s)
- Isabelle Plo
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
| | - Christine Bellanné-Chantelot
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Department of Genetics, AP-HP Hôpitaux Universitaires Pitié Salpêtrière - Charles Foix, UPMC Univ Paris 06, Paris, France
| | - Matthieu Mosca
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
| | - Stefania Mazzi
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Université Paris-Diderot, Paris, France
| | - Caroline Marty
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
| | - William Vainchenker
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
- *Correspondence: William Vainchenker,
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14
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An incomplete trafficking defect to the cell-surface leads to paradoxical thrombocytosis for human and murine MPL P106L. Blood 2016; 128:3146-3158. [PMID: 28034873 DOI: 10.1182/blood-2016-06-722058] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 11/03/2016] [Indexed: 12/30/2022] Open
Abstract
The mechanisms behind the hereditary thrombocytosis induced by the thrombopoietin (THPO) receptor MPL P106L mutant remain unknown. A complete trafficking defect to the cell surface has been reported, suggesting either weak constitutive activity or nonconventional THPO-dependent mechanisms. Here, we report that the thrombocytosis phenotype induced by MPL P106L belongs to the paradoxical group, where low MPL levels on platelets and mature megakaryocytes (MKs) lead to high serum THPO levels, whereas weak but not absent MPL cell-surface localization in earlier MK progenitors allows response to THPO by signaling and amplification of the platelet lineage. MK progenitors from patients showed no spontaneous growth and responded to THPO, and MKs expressed MPL on their cell surface at low levels, whereas their platelets did not respond to THPO. Transduction of MPL P106L in CD34+ cells showed that this receptor was more efficiently localized at the cell surface on immature than on mature MKs, explaining a proliferative response to THPO of immature cells and a defect in THPO clearance in mature cells. In a retroviral mouse model performed in Mpl-/- mice, MPL P106L could induce a thrombocytosis phenotype with high circulating THPO levels. Furthermore, we could select THPO-dependent cell lines with more cell-surface MPL P106L localization that was detected by flow cytometry and [125I]-THPO binding. Altogether, these results demonstrate that MPL P106L is a receptor with an incomplete defect in trafficking, which induces a low but not absent localization of the receptor on cell surface and a response to THPO in immature MK cells.
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15
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Verger E, Teillet F, Conejero C, Letort G, Chomienne C, Giraudier S, Cassinat B. Unexplained thrombocytosis: association of Baltimore polymorphism with germline MPL nonsense mutation. Br J Haematol 2015; 175:167-9. [PMID: 26568271 DOI: 10.1111/bjh.13840] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Emmanuelle Verger
- Service de Biologie Cellulaire, AP-HP, Hopital Saint-Louis, Paris, France
| | - France Teillet
- Laboratoire d'Hématologie, AP-HP, Hopital Louis Mourier, Colombes, France
| | | | - Gil Letort
- Inserm UMR-S 1131, Hopital Saint-Louis, Paris, France
| | - Christine Chomienne
- Service de Biologie Cellulaire, AP-HP, Hopital Saint-Louis, Paris, France.,Inserm UMR-S 1131, Hopital Saint-Louis, Paris, France.,Université Paris-Diderot, Paris, France
| | - Stephane Giraudier
- Faculte de medecine, Université Paris 12, Creteil, France.,Laboratoire d'Hématologie, AP-HP, Hopital Henri Mondor, Creteil, France
| | - Bruno Cassinat
- Service de Biologie Cellulaire, AP-HP, Hopital Saint-Louis, Paris, France. .,Inserm UMR-S 1131, Hopital Saint-Louis, Paris, France.
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