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Masson E, Berthet S, Le Gac G, Le Rhun M, Ka C, Autret S, Gourlaouen I, Cooper DN, Férec C, Rebours V, Chen JM. Identification of protease-sensitive but not misfolding PNLIP variants in familial and hereditary pancreatitis. Pancreatology 2023; 23:507-511. [PMID: 37270400 DOI: 10.1016/j.pan.2023.05.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/24/2023] [Accepted: 05/26/2023] [Indexed: 06/05/2023]
Abstract
Mutations in the PNLIP gene have recently been implicated in chronic pancreatitis. Several PNLIP missense variants have been reported to cause protein misfolding and endoplasmic reticulum stress although genetic evidence supporting their association with chronic pancreatitis is currently lacking. Protease-sensitive PNLIP missense variants have also been associated with early-onset chronic pancreatitis although the underlying pathological mechanism remains enigmatic. Herein, we provide new evidence to support the association of protease-sensitive PNLIP variants (but not misfolding PNLIP variants) with pancreatitis. Specifically, we identified protease-sensitive PNLIP variants in 5 of 373 probands (1.3%) with a positive family history of pancreatitis. The protease-sensitive variants, p.F300L and p.I265R, were found to segregate with the disease in three families, including one exhibiting a classical autosomal dominant inheritance pattern. Consistent with previous findings, protease-sensitive variant-positive patients were often characterized by early-onset disease and invariably experienced recurrent acute pancreatitis, although none has so far developed chronic pancreatitis.
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Affiliation(s)
- Emmanuelle Masson
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200, Brest, France; Service de Génétique Médicale et de Biologie de la Reproduction, CHRU Brest, F-29200, Brest, France
| | - Stéphanie Berthet
- Service de Pédiatrie, Hépato-Gastro-Entérologie et Nutrition Pédiatrique, Hôpitaux Pédiatriques de Nice CHU Lenval, Nice, France
| | - Gerald Le Gac
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200, Brest, France; Service de Génétique Médicale et de Biologie de la Reproduction, CHRU Brest, F-29200, Brest, France
| | - Marc Le Rhun
- Service d'Hépato-Gastroentérologie et Assistance Nutritionnelle, Institut des Maladies de l'Appareil Digestif (IMAD), Centre Hospitalo-Universitaire (CHU), Nantes, France
| | - Chandran Ka
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200, Brest, France; Service de Génétique Médicale et de Biologie de la Reproduction, CHRU Brest, F-29200, Brest, France
| | - Sandrine Autret
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200, Brest, France; Service de Génétique Médicale et de Biologie de la Reproduction, CHRU Brest, F-29200, Brest, France
| | | | - David N Cooper
- Institute of Medical Genetics, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Claude Férec
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200, Brest, France
| | - Vinciane Rebours
- Pancreatology and Digestive Oncology Department, Beaujon Hospital, APHP - Clichy, Université Paris Cité, Paris, France
| | - Jian-Min Chen
- Univ Brest, Inserm, EFS, UMR 1078, GGB, F-29200, Brest, France.
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Couloigner L, Planes M, Ka C, Audebert-Bellanger S, Redon S, Benech C, Rouault K, Küry S, Peudenier S, Autret S, Gourlaouen I, Bonneau D, Odent S, Bézieau S, Gilbert-Dussardier B, Toutain A, Boland A, Deleuze JF, Le Marechal C, Le Gac G, Ferec C, Uguen K. A new case of Kaufman Oculocerebrofacial syndrome caused by two splicing variants in UBE3B and review of the literature. Clin Genet 2023; 103:377-379. [PMID: 36444497 DOI: 10.1111/cge.14270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/20/2022] [Accepted: 11/22/2022] [Indexed: 11/30/2022]
Affiliation(s)
- Loïc Couloigner
- Service de Génétique Médicale, CHU de Brest, Brest, France
- Centre de Référence Déficiences Intellectuelles, Service de Pédiatrie, CHU de Brest, Brest, France
| | - Marc Planes
- Service de Génétique Médicale, CHU de Brest, Brest, France
- Centre de Référence Déficiences Intellectuelles, Service de Pédiatrie, CHU de Brest, Brest, France
| | - Chandran Ka
- Service de Génétique Médicale, CHU de Brest, Brest, France
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France
| | - Séverine Audebert-Bellanger
- Service de Génétique Médicale, CHU de Brest, Brest, France
- Centre de Référence Déficiences Intellectuelles, Service de Pédiatrie, CHU de Brest, Brest, France
| | - Sylvia Redon
- Service de Génétique Médicale, CHU de Brest, Brest, France
- Centre de Référence Déficiences Intellectuelles, Service de Pédiatrie, CHU de Brest, Brest, France
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France
| | | | - Karen Rouault
- Service de Génétique Médicale, CHU de Brest, Brest, France
- Centre de Référence Déficiences Intellectuelles, Service de Pédiatrie, CHU de Brest, Brest, France
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France
| | - Sebastien Küry
- Service de Génétique Médicale, Nantes Université, CHU Nantes, Nantes, France
- INSERM, l'institut du thorax, Nantes Université, CHU Nantes, CNRS, Nantes, France
| | - Sylviane Peudenier
- Centre de Référence Déficiences Intellectuelles, Service de Pédiatrie, CHU de Brest, Brest, France
| | - Sandrine Autret
- Service de Génétique Médicale, CHU de Brest, Brest, France
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France
| | | | | | - Sylvie Odent
- Service de Génétique Clinique, CHU de Rennes, UMR6290 CNRS, Université Rennes, Rennes, France
| | - Stéphane Bézieau
- Service de Génétique Médicale, Nantes Université, CHU Nantes, Nantes, France
- INSERM, l'institut du thorax, Nantes Université, CHU Nantes, CNRS, Nantes, France
| | | | - Annick Toutain
- Service de Génétique, CHU de Tours, UMR1253 iBrain INSERM, Université de Tours, Tours, France
| | - Anne Boland
- Centre National de Recherche en Génomique Humaine, Université Paris-Saclay, CEA, Evry, France
| | - Jean-François Deleuze
- Centre National de Recherche en Génomique Humaine, Université Paris-Saclay, CEA, Evry, France
| | - Cédric Le Marechal
- Service de Génétique Médicale, CHU de Brest, Brest, France
- Centre de Référence Déficiences Intellectuelles, Service de Pédiatrie, CHU de Brest, Brest, France
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France
| | - Gérald Le Gac
- Service de Génétique Médicale, CHU de Brest, Brest, France
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France
| | - Claude Ferec
- Service de Génétique Médicale, CHU de Brest, Brest, France
- Centre de Référence Déficiences Intellectuelles, Service de Pédiatrie, CHU de Brest, Brest, France
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France
| | - Kevin Uguen
- Service de Génétique Médicale, CHU de Brest, Brest, France
- Centre de Référence Déficiences Intellectuelles, Service de Pédiatrie, CHU de Brest, Brest, France
- Univ Brest, Inserm, EFS, UMR 1078, GGB, Brest, France
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Le Gac G, Scotet V, Gourlaouen I, L'Hostis C, Merour MC, Karim Z, Deugnier Y, Bardou-Jacquet E, Lefebvre T, Assari S, Ferec C. Prevalence of HFE-related haemochromatosis and secondary causes of hyperferritinaemia and their association with iron overload in 1059 French patients treated by venesection. Aliment Pharmacol Ther 2022; 55:1016-1027. [PMID: 35122291 DOI: 10.1111/apt.16775] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/02/2021] [Accepted: 01/04/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Venesection is the key therapy in haemochromatosis, but it remains controversial in hyperferritinaemia with moderate iron accumulation. There is substantial evidence that the results of HFE genotyping are routinely misinterpreted, while elevated serum ferritin has become more frequent in recent years in white adult populations following the increase of obesity and metabolic traits. AIMS To examine the reasons for prescribing venesection in 1,059 French patients during the period 2012-2015, determine the true prevalence of HFE-related haemochromatosis, and compare iron overload profiles between haemochromatosis and non-haemochromatosis patients. RESULTS Only 258 of the 488 patients referred for haemochromatosis had the p.[Cys282Tyr];[Cys282Tyr] disease causative genotype (adjusted prevalence: 24.4%). Of the 801 remaining patients, 112 (14.0%) had the debated p.[Cys282Tyr];[His63Asp] compound heterozygote genotype, 643 (80.3%) had central obesity, 475 (59.3%) had metabolic syndrome (MetS) and 93 (11.6%) were heavy drinkers. The non-haemochromatosis patients started therapeutic venesection 9 years later than haemochromatosis patients (P < 0.001). Despite similar serum ferritin values, they had lower transferrin saturation (41.1% vs 74.3%; P < 0.001), lower amounts of iron removed by venesection (1.7 vs 3.2 g; P < 0.001) and lower hepatic iron concentrations (107 vs 237 µmol/g; P < 0.001). CONCLUSIONS Haemochromatosis is over-diagnosed and is no longer the main reason for therapeutic venesection in France. Obesity and other metabolic abnormalities are frequently associated with mild elevation of serum ferritin, the MetS is confirmed in ~50% of treated patients. There is a minimal relationship between serum ferritin and iron overload in non-p.Cys282Tyr homozygotes. Our observations raise questions about venesection indications in non-haemochromatosis patients.
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Le Tertre M, Ka C, Raud L, Berlivet I, Gourlaouen I, Richard G, Uguen K, Chen JM, Férec C, Fichou Y, Le Gac G. Splicing analysis of SLC40A1 missense variations and contribution to hemochromatosis type 4 phenotypes. Blood Cells Mol Dis 2020; 87:102527. [PMID: 33341511 DOI: 10.1016/j.bcmd.2020.102527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 02/09/2023]
Abstract
Hemochromatosis type 4, or ferroportin disease, is considered as the second leading cause of primary iron overload after HFE-related hemochromatosis. The disease, which is predominantly associated with missense variations in the SLC40A1 gene, is characterized by wide clinical heterogeneity. We tested the possibility that some of the reported missense mutations, despite their positions within exons, cause splicing defects. Fifty-eight genetic variants were selected from the literature based on two criteria: a precise description of the nucleotide change and individual evidence of iron overload. The selected variants were investigated by different in silico prediction tools and prioritized for midigene splicing assays. Of the 15 variations tested in vitro, only two were associated with splicing changes. We confirm that the c.1402G>A transition (p.Gly468Ser) disrupts the exon 7 donor site, leading to the use of an exonic cryptic splicing site and the generation of a truncated reading frame. We observed, for the first time, that the p.Gly468Ser substitution has no effect on the ferroportin iron export function. We demonstrate alternative splicing of exon 5 in different cell lines and show that the c.430A>G (p.Asn144Asp) variant promotes exon 5 inclusion. This could be part of a gain-of-function mechanism. We conclude that splicing mutations rarely contribute to hemochromatosis type 4 phenotypes. An in-depth investigation of exon 5 auxiliary splicing sequences may help to elucidate the mechanism by which splicing regulatory proteins regulate the production of the full length SLC40A1 transcript and to clarify its physiological importance.
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Affiliation(s)
- Marlène Le Tertre
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; CHRU de Brest, Service de Génétique Médicale et Biologie de la Reproduction, Laboratoire de Génétique Moléculaire et Histocompatibilité, F-29200, France
| | - Chandran Ka
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; CHRU de Brest, Service de Génétique Médicale et Biologie de la Reproduction, Laboratoire de Génétique Moléculaire et Histocompatibilité, F-29200, France; Laboratory of Excellence GR-Ex, F-75015, France
| | - Loann Raud
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; Association Gaétan Saleün, F-29200, France
| | | | - Isabelle Gourlaouen
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; Laboratory of Excellence GR-Ex, F-75015, France
| | | | - Kévin Uguen
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; CHRU de Brest, Service de Génétique Médicale et Biologie de la Reproduction, Laboratoire de Génétique Moléculaire et Histocompatibilité, F-29200, France
| | - Jian-Min Chen
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France
| | - Claude Férec
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; CHRU de Brest, Service de Génétique Médicale et Biologie de la Reproduction, Laboratoire de Génétique Moléculaire et Histocompatibilité, F-29200, France; Association Gaétan Saleün, F-29200, France
| | - Yann Fichou
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; Laboratory of Excellence GR-Ex, F-75015, France
| | - Gérald Le Gac
- Univ Brest, Inserm, EFS, UMR1078, GGB, F-29200, France; CHRU de Brest, Service de Génétique Médicale et Biologie de la Reproduction, Laboratoire de Génétique Moléculaire et Histocompatibilité, F-29200, France; Laboratory of Excellence GR-Ex, F-75015, France.
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5
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Rodríguez-Palmero A, Schlüter A, Verdura E, Ruiz M, Martínez JJ, Gourlaouen I, Ka C, Lobato R, Casasnovas C, Le Gac G, Fourcade S, Pujol A. A novel hypomorphic splice variant in EIF2B5 gene is associated with mild ovarioleukodystrophy. Ann Clin Transl Neurol 2020; 7:1574-1579. [PMID: 33245593 PMCID: PMC7480926 DOI: 10.1002/acn3.51131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 06/27/2020] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE To identify the genetic cause in an adult ovarioleukodystrophy patient resistant to diagnosis. METHODS We applied whole-exome sequencing (WES) to a vanishing white matter disease patient associated with premature ovarian failure at 26 years of age. We functionally tested an intronic variant by RT-PCR on patient's peripheral blood mononuclear cells (PBMC) and by minigene splicing assay. RESULTS WES analysis identified two novel variants in the EIF2B5 gene: c.725A > G (p.Tyr242Cys) and an intronic noncanonical mutation (c.1156 + 13G>A). This intronic mutation resulted into generation of various isoforms both in patient's PBMC and in the minigene splicing assay, showing that ~20% residual wild-type isoform is still expressed by the intronic-mutated allele alone, concordant with an hypomorphic effect of this variant. CONCLUSION We report two novel variants in EIF2B5, one of them a noncanonical intronic splice variant, located at a +13 intronic position. This position is mutated only in 0.05% of ClinVar intronic mutations described so far. Furthermore, we illustrate how minigene splicing assay may be advantageous when validating splice-altering variants, in this case highlighting the coexistence of wild-type and mutated forms, probably explaining this patient's milder, late-onset phenotype.
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Affiliation(s)
- Agustí Rodríguez-Palmero
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Spain.,Pediatrics Department, University Hospital Germans Trias i Pujol, Badalona, 08916, Spain
| | - Agatha Schlüter
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Edgard Verdura
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Montserrat Ruiz
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Juan José Martínez
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | | | - Chandran Ka
- INSERM U1078, Brest, France.,Laboratory of Excellence GR-Ex, Paris, France.,Laboratoire de Génétique Moleculaire et Histocompatibilité, CHRU de Brest, Hôpital Morvan, Brest, France
| | - Ricardo Lobato
- Neurology Department, Hospital Universitario Infanta Sofía, San Sebastián de los Reyes, 28703, Spain
| | - Carlos Casasnovas
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain.,Neuromuscular Unit, Neurology Department, Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, 08908, Spain
| | - Gérald Le Gac
- INSERM U1078, Brest, France.,Laboratory of Excellence GR-Ex, Paris, France.,Laboratoire de Génétique Moleculaire et Histocompatibilité, CHRU de Brest, Hôpital Morvan, Brest, France.,Université Bretagne Loire, Université de Bretagne Occidentale, IBSAM, Brest, France
| | - Stéphane Fourcade
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Aurora Pujol
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, 08908, Spain.,Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain.,Catalan Institution of Research and Advanced Studies (ICREA), Barcelona, Spain
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Martinez G, Beurois J, Dacheux D, Cazin C, Bidart M, Kherraf ZE, Robinson DR, Satre V, Le Gac G, Ka C, Gourlaouen I, Fichou Y, Petre G, Dulioust E, Zouari R, Thierry-Mieg N, Touré A, Arnoult C, Bonhivers M, Ray P, Coutton C. Biallelic variants in MAATS1 encoding CFAP91, a calmodulin-associated and spoke-associated complex protein, cause severe astheno-teratozoospermia and male infertility. J Med Genet 2020; 57:708-716. [PMID: 32161152 DOI: 10.1136/jmedgenet-2019-106775] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/25/2020] [Accepted: 01/27/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND Multiple morphological abnormalities of the flagella (MMAF) consistently lead to male infertility due to a reduced or absent sperm motility defined as asthenozoospermia. Despite numerous genes recently described to be recurrently associated with MMAF, more than half of the cases analysed remain unresolved, suggesting that many yet uncharacterised gene defects account for this phenotype METHODS: Exome sequencing was performed on 167 infertile men with an MMAF phenotype. Immunostaining and transmission electron microscopy (TEM) in sperm cells from affected individuals were performed to characterise the ultrastructural sperm defects. Gene inactivation using RNA interference (RNAi) was subsequently performed in Trypanosoma. RESULTS We identified six unrelated affected patients carrying a homozygous deleterious variants in MAATS1, a gene encoding CFAP91, a calmodulin-associated and spoke-associated complex (CSC) protein. TEM and immunostaining experiments in sperm cells showed severe central pair complex (CPC) and radial spokes defects. Moreover, we confirmed that the WDR66 protein is a physical and functional partner of CFAP91 into the CSC. Study of Trypanosoma MAATS1's orthologue (TbCFAP91) highlighted high sequence and structural analogies with the human protein and confirmed the axonemal localisation of the protein. Knockdown of TbCFAP91 using RNAi impaired flagellar movement led to CPC defects in Trypanosoma as observed in humans. CONCLUSIONS We showed that CFAP91 is essential for normal sperm flagellum structure and function in human and Trypanosoma and that biallelic variants in this gene lead to severe flagellum malformations resulting in astheno-teratozoospermia and primary male infertility.
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Affiliation(s)
- Guillaume Martinez
- Univ. Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, Team Genetics Epigenetics and Therapies of Infertility, Grenoble, France.,CHU Grenoble Alpes, UM de Génétique Chromosomique, Grenoble, France
| | - Julie Beurois
- Univ. Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, Team Genetics Epigenetics and Therapies of Infertility, Grenoble, France
| | - Denis Dacheux
- Université de Bordeaux, Microbiologie Fondamentale et Pathogénicité, CNRS UMR 5234, Bordeaux, France.,Institut Polytechnique de Bordeaux, Microbiologie Fondamentale et Pathogénicité, CNRS UMR 5234, Bordeaux, France
| | - Caroline Cazin
- Univ. Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, Team Genetics Epigenetics and Therapies of Infertility, Grenoble, France
| | - Marie Bidart
- Univ. Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, Team Genetics Epigenetics and Therapies of Infertility, Grenoble, France.,CHU Grenoble Alpes, Unité Médicale de Génétique Moléculaire : Maladies Héréditaires et Oncologie, Pôle Biologie, Institut de Biologie et de Pathologie, Grenoble, France
| | - Zine-Eddine Kherraf
- Univ. Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, Team Genetics Epigenetics and Therapies of Infertility, Grenoble, France.,CHU Grenoble Alpes, UM GI-DPI, Grenoble, France
| | - Derrick R Robinson
- Institut Polytechnique de Bordeaux, Microbiologie Fondamentale et Pathogénicité, CNRS UMR 5234, Bordeaux, France
| | - Véronique Satre
- Univ. Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, Team Genetics Epigenetics and Therapies of Infertility, Grenoble, France.,CHU Grenoble Alpes, UM de Génétique Chromosomique, Grenoble, France
| | - Gerald Le Gac
- INSERM UMR1078, Université Bretagne Loire - Université de Brest, Etablissement Français du Sang - Bretagne, Institut Brestois Santé-Agro-Matière, Brest, France.,Service de Génétique Médicale et Biologie de la Reproduction, Laboratoire de Génétique Moléculaire et Histocompatibilité, CHRU de Brest, Hôpital Morvan, Brest, France
| | - Chandran Ka
- INSERM UMR1078, Université Bretagne Loire - Université de Brest, Etablissement Français du Sang - Bretagne, Institut Brestois Santé-Agro-Matière, Brest, France
| | - Isabelle Gourlaouen
- INSERM UMR1078, Université Bretagne Loire - Université de Brest, Etablissement Français du Sang - Bretagne, Institut Brestois Santé-Agro-Matière, Brest, France
| | - Yann Fichou
- INSERM UMR1078, Université Bretagne Loire - Université de Brest, Etablissement Français du Sang - Bretagne, Institut Brestois Santé-Agro-Matière, Brest, France
| | - Graciane Petre
- INSERM U1205, UFR Chimie Biologie, Univ. Grenoble Alpes, Grenoble, France
| | - Emmanuel Dulioust
- Laboratoire d'Histologie Embryologie - Biologie de la Reproduction, GH Cochin Broca Hôtel Dieu, Assistance Publique-Hôpitaux de Paris, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Raoudha Zouari
- Polyclinique les Jasmins, Centre d'Aide Médicale à la Procréation, Centre Urbain Nord, Tunis, Tunisia
| | | | - Aminata Touré
- Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France.,INSERM U1016, Institut Cochin, Paris, France.,Centre National de la Recherche Scientifique UMR8104, Paris, France
| | - Christophe Arnoult
- Univ. Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, Team Genetics Epigenetics and Therapies of Infertility, Grenoble, France
| | - Mélanie Bonhivers
- Université de Bordeaux, Microbiologie Fondamentale et Pathogénicité, CNRS UMR 5234, Bordeaux, France
| | - Pierre Ray
- Univ. Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, Team Genetics Epigenetics and Therapies of Infertility, Grenoble, France.,CHU Grenoble Alpes, UM GI-DPI, Grenoble, France
| | - Charles Coutton
- Univ. Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, Team Genetics Epigenetics and Therapies of Infertility, Grenoble, France .,CHU Grenoble Alpes, UM de Génétique Chromosomique, Grenoble, France
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Guellec J, Elbahnsi A, Le Tertre M, Uguen K, Gourlaouen I, Férec C, Ka C, Callebaut I, Le Gac G. Molecular model of the ferroportin intracellular gate and implications for the human iron transport cycle and hemochromatosis type 4A. FASEB J 2019; 33:14625-14635. [PMID: 31690120 DOI: 10.1096/fj.201901857r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ferroportin 1 (FPN1) is a major facilitator superfamily transporter that is essential for proper maintenance of human iron homeostasis at the systemic and cellular level. FPN1 dysfunction leads to the progressive accumulation of iron in reticuloendothelial cells, causing hemochromatosis type 4A (or ferroportin disease), an autosomal dominant disorder that displays large phenotypic heterogeneity. Although crystal structures have unveiled the outward- and inward-facing conformations of the bacterial homolog Bdellovibrio bacteriovorus Fpn (or Bd2019) and calcium has recently been identified as an essential cofactor, our molecular understanding of the iron transport mechanism remains incomplete. Here, we used a combination of molecular modeling, molecular dynamics simulations, and Ala site-directed mutagenesis, followed by complementary in vitro functional analyses, to explore the structural architecture of the human FPN1 intracellular gate. We reveal an interdomain network that involves 5 key amino acids and is likely very important for stability of the iron exporter facing the extracellular milieu. We also identify inter- and intradomain interactions that rely on the 2 Asp84 and Asn174 critical residues and do not exist in the bacterial homolog. These interactions are thought to play an important role in the modulation of conformational changes during the transport cycle. We interpret these results in the context of hemochromatosis type 4A, reinforcing the idea that different categories of loss-of-function mutations exist. Our findings provide an unprecedented view of the human FPN1 outward-facing structure and the particular function of the so-called "gating residues" in the mechanism of iron export.-Guellec, J., Elbahnsi, A., Le Tertre, M., Uguen, K., Gourlaouen, I., Férec, C., Ka, C., Callebaut, I., Le Gac, G. Molecular model of the ferroportin intracellular gate and implications for the human iron transport cycle and hemochromatosis type 4A.
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Affiliation(s)
- Julie Guellec
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France.,Association Gaetan Saleun, Brest, France
| | - Ahmad Elbahnsi
- Muséum National d'Histoire Naturelle, UMR Centre National de la Recherche Scientifique (CNRS) 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Université, Paris, France
| | - Marlène Le Tertre
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France.,Service de Génétique Médicale, Centre Hospitalier Régional et Universitaire (CHRU) de Brest, Hôpital Morvan, Brest, France; and
| | - Kévin Uguen
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France.,Service de Génétique Médicale, Centre Hospitalier Régional et Universitaire (CHRU) de Brest, Hôpital Morvan, Brest, France; and
| | - Isabelle Gourlaouen
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France
| | - Claude Férec
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France.,Association Gaetan Saleun, Brest, France.,Service de Génétique Médicale, Centre Hospitalier Régional et Universitaire (CHRU) de Brest, Hôpital Morvan, Brest, France; and
| | - Chandran Ka
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France.,Service de Génétique Médicale, Centre Hospitalier Régional et Universitaire (CHRU) de Brest, Hôpital Morvan, Brest, France; and.,Laboratory of Excellence Laboratory of Excellence (GR-Ex), Paris, France
| | - Isabelle Callebaut
- Muséum National d'Histoire Naturelle, UMR Centre National de la Recherche Scientifique (CNRS) 7590, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), Sorbonne Université, Paris, France
| | - Gérald Le Gac
- INSERM Unité Mixte de Recherche (UMR) 1078, Etablissement Français du Sang-Bretagne, Institut Brestois Santé-Agro-Matière, Université Bretagne Loire-Université de Brest, Brest, France.,Service de Génétique Médicale, Centre Hospitalier Régional et Universitaire (CHRU) de Brest, Hôpital Morvan, Brest, France; and.,Laboratory of Excellence Laboratory of Excellence (GR-Ex), Paris, France
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Raud L, Ka C, Gourlaouen I, Callebaut I, Férec C, Le Gac G, Fichou Y. Functional analysis of novelRHDvariants: splicing disruption is likely to be a common mechanism of variant D phenotype. Transfusion 2019; 59:1367-1375. [DOI: 10.1111/trf.15210] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 11/22/2018] [Accepted: 12/06/2018] [Indexed: 02/01/2023]
Affiliation(s)
- Loann Raud
- UMR1078 "Génétique, Génomique Fonctionnelle et Biotechnologies"; INSERM, EFS, Université de Brest, IBSAM, CHU de Brest; Brest France
- Laboratory of Excellence GR-Ex; Paris France
| | - Chandran Ka
- UMR1078 "Génétique, Génomique Fonctionnelle et Biotechnologies"; INSERM, EFS, Université de Brest, IBSAM, CHU de Brest; Brest France
- Laboratory of Excellence GR-Ex; Paris France
| | - Isabelle Gourlaouen
- UMR1078 "Génétique, Génomique Fonctionnelle et Biotechnologies"; INSERM, EFS, Université de Brest, IBSAM, CHU de Brest; Brest France
- Laboratory of Excellence GR-Ex; Paris France
| | - Isabelle Callebaut
- IMPMC, Sorbonne Universités - UMR CNRS 7590, UPMC Univ Paris 06, Muséum d'Histoire Naturelle, IRD UMR 206; Paris France
| | - Claude Férec
- UMR1078 "Génétique, Génomique Fonctionnelle et Biotechnologies"; INSERM, EFS, Université de Brest, IBSAM, CHU de Brest; Brest France
- Laboratory of Excellence GR-Ex; Paris France
| | - Gérald Le Gac
- UMR1078 "Génétique, Génomique Fonctionnelle et Biotechnologies"; INSERM, EFS, Université de Brest, IBSAM, CHU de Brest; Brest France
- Laboratory of Excellence GR-Ex; Paris France
| | - Yann Fichou
- UMR1078 "Génétique, Génomique Fonctionnelle et Biotechnologies"; INSERM, EFS, Université de Brest, IBSAM, CHU de Brest; Brest France
- Laboratory of Excellence GR-Ex; Paris France
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9
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Ka C, Guellec J, Pepermans X, Kannengiesser C, Ged C, Wuyts W, Cassiman D, de Ledinghen V, Varet B, de Kerguenec C, Oudin C, Gourlaouen I, Lefebvre T, Férec C, Callebaut I, Le Gac G. The SLC40A1 R178Q mutation is a recurrent cause of hemochromatosis and is associated with a novel pathogenic mechanism. Haematologica 2018; 103:1796-1805. [PMID: 30002125 PMCID: PMC6278975 DOI: 10.3324/haematol.2018.189845] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 07/06/2018] [Indexed: 12/29/2022] Open
Abstract
Hemochromatosis type 4 is one of the most common causes of primary iron overload, after HFE-related hemochromatosis. It is an autosomal dominant disorder, primarily due to missense mutations in SLC40A1. This gene encodes ferroportin 1 (FPN1), which is the sole iron export protein reported in mammals. Not all heterozygous missense mutations in SLC40A1 are disease-causing. Due to phenocopies and an increased demand for genetic testing, rare SLC40A1 variations are fortuitously observed in patients with a secondary cause of hyperferritinemia. Structure/function analysis is the most effective way of establishing causality when clinical and segregation data are lacking. It can also provide important insights into the mechanism of iron egress and FPN1 regulation by hepcidin. The present study aimed to determine the pathogenicity of the previously reported p.Arg178Gln variant. We present the biological, clinical, histological and radiological findings of 22 patients from six independent families of French, Belgian or Iraqi decent. Despite phenotypic variability, all patients with p.Arg178Gln had elevated serum ferritin concentrations and normal to low transferrin saturation levels. In vitro experiments demonstrated that the p.Arg178Gln mutant reduces the ability of FPN1 to export iron without causing protein mislocalization. Based on a comparative model of the 3D structure of human FPN1 in an outward facing conformation, we argue that p.Arg178 is part of an interaction network modulating the conformational changes required for iron transport. We conclude that p.Arg178Gln represents a new category of loss-of-function mutations and that the study of “gating residues” is necessary in order to fully understand the action mechanism of FPN1.
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Affiliation(s)
- Chandran Ka
- UMR1078, INSERM, Université Bretagne Loire - Université de Bretagne Occidentale, Etablissement Français du Sang - Bretagne, Institut Brestois Santé-Agro-Matière, Brest, France.,Laboratoire de Génétique Moléculaire et Histocompatibilité, CHRU de Brest, Hôpital Morvan, France.,Laboratory of Excellence GR-Ex, Paris, France
| | - Julie Guellec
- UMR1078, INSERM, Université Bretagne Loire - Université de Bretagne Occidentale, Etablissement Français du Sang - Bretagne, Institut Brestois Santé-Agro-Matière, Brest, France.,Laboratory of Excellence GR-Ex, Paris, France.,Association Gaetan Saleun, Brest, France
| | - Xavier Pepermans
- Center for Human Genetics, University Hospital of St-Luc, Brussels, Belgium
| | - Caroline Kannengiesser
- Laboratory of Excellence GR-Ex, Paris, France.,UMR1149, INSERM, Centre de Recherche sur l'Inflammation, Université Paris Diderot, AP-HP, Hôpital Bichat, Département de Génétique, France.,On behalf of the French National Network for the Molecular Diagnosis of Inherited Iron Overload Disorders (J. Rochette, E. Cadet, C. Kannengiesser, H. Puy, C. Ged, H. de Verneuil, G. Le Gac, C. Férec, S. Pissard, V. Gérolami), Brest, France
| | - Cécile Ged
- On behalf of the French National Network for the Molecular Diagnosis of Inherited Iron Overload Disorders (J. Rochette, E. Cadet, C. Kannengiesser, H. Puy, C. Ged, H. de Verneuil, G. Le Gac, C. Férec, S. Pissard, V. Gérolami), Brest, France.,INSERM U1035, BMGIC, CHU de Bordeaux, Laboratoire de Biochimie et Biologie Moléculaire, France
| | - Wim Wuyts
- Department of Medical Genetics, University and University Hospital of Antwerp, Edegem, Belgium
| | - David Cassiman
- Department of Gastroenterology-Hepatology and Metabolic Center, University Hospital of Leuven, Belgium
| | - Victor de Ledinghen
- Department of Gastroenterology and Digestive Oncology, University Hospital of Bordeaux, France
| | - Bruno Varet
- Université Paris Descartes et AP-HP, Hôpital Necker, Service d'Hématologie, France
| | | | - Claire Oudin
- UMR1149, INSERM, Centre de Recherche sur l'Inflammation, Université Paris Diderot, AP-HP, Hôpital Bichat, Département de Génétique, France
| | - Isabelle Gourlaouen
- UMR1078, INSERM, Université Bretagne Loire - Université de Bretagne Occidentale, Etablissement Français du Sang - Bretagne, Institut Brestois Santé-Agro-Matière, Brest, France.,Laboratory of Excellence GR-Ex, Paris, France
| | - Thibaud Lefebvre
- UMR1149, INSERM, Centre de Recherche sur l'Inflammation, Université Paris Diderot, AP-HP, Hôpital Bichat, Département de Génétique, France
| | - Claude Férec
- UMR1078, INSERM, Université Bretagne Loire - Université de Bretagne Occidentale, Etablissement Français du Sang - Bretagne, Institut Brestois Santé-Agro-Matière, Brest, France.,Laboratoire de Génétique Moléculaire et Histocompatibilité, CHRU de Brest, Hôpital Morvan, France.,On behalf of the French National Network for the Molecular Diagnosis of Inherited Iron Overload Disorders (J. Rochette, E. Cadet, C. Kannengiesser, H. Puy, C. Ged, H. de Verneuil, G. Le Gac, C. Férec, S. Pissard, V. Gérolami), Brest, France
| | - Isabelle Callebaut
- UMR7590, CNRS, Sorbonne Universités, Université Pierre et Marie Curie-Paris, France
| | - Gérald Le Gac
- UMR1078, INSERM, Université Bretagne Loire - Université de Bretagne Occidentale, Etablissement Français du Sang - Bretagne, Institut Brestois Santé-Agro-Matière, Brest, France .,Laboratoire de Génétique Moléculaire et Histocompatibilité, CHRU de Brest, Hôpital Morvan, France.,Laboratory of Excellence GR-Ex, Paris, France.,On behalf of the French National Network for the Molecular Diagnosis of Inherited Iron Overload Disorders (J. Rochette, E. Cadet, C. Kannengiesser, H. Puy, C. Ged, H. de Verneuil, G. Le Gac, C. Férec, S. Pissard, V. Gérolami), Brest, France
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10
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Uguen K, Scotet V, Ka C, Gourlaouen I, L'hostis C, Merour MC, Cuppens T, Ferec C, Le Gac G. Diagnostic value of targeted next-generation sequencing in suspected hemochromatosis patients with a single copy of the HFE p.Cys282Tyr causative allele. Am J Hematol 2017; 92:E664-E666. [PMID: 29084376 DOI: 10.1002/ajh.24912] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 09/19/2017] [Indexed: 02/07/2023]
Affiliation(s)
- Kevin Uguen
- Université Bretagne Loire, Université de Bretagne Occidentale, IBSAM; Brest France
| | - Virginie Scotet
- Inserm U1078; Brest France
- Etablissement Français du Sang; Brest France
| | - Chandran Ka
- Inserm U1078; Brest France
- Laboratory of Excellence GR-Ex; Paris France
- Laboratoire de Genetique Moleculaire et Histocompatibilité, CHRU de Brest, Hopital Morvan; Brest France
| | - Isabelle Gourlaouen
- Inserm U1078; Brest France
- Etablissement Français du Sang; Brest France
- Laboratoire de Genetique Moleculaire et Histocompatibilité, CHRU de Brest, Hopital Morvan; Brest France
| | - Carine L'hostis
- Inserm U1078; Brest France
- Association Gaetan Saleun; Brest France
| | | | - Tania Cuppens
- Université Bretagne Loire, Université de Bretagne Occidentale, IBSAM; Brest France
- Inserm U1078; Brest France
| | - Claude Ferec
- Université Bretagne Loire, Université de Bretagne Occidentale, IBSAM; Brest France
- Inserm U1078; Brest France
- Etablissement Français du Sang; Brest France
- Laboratoire de Genetique Moleculaire et Histocompatibilité, CHRU de Brest, Hopital Morvan; Brest France
| | - Gerald Le Gac
- Université Bretagne Loire, Université de Bretagne Occidentale, IBSAM; Brest France
- Inserm U1078; Brest France
- Etablissement Français du Sang; Brest France
- Laboratory of Excellence GR-Ex; Paris France
- Laboratoire de Genetique Moleculaire et Histocompatibilité, CHRU de Brest, Hopital Morvan; Brest France
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11
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Le Gac G, Scotet V, Gourlaouen I, L’Hostis C, Merour MC, Assari S, Ferec C. Importance du diagnostic différentiel de l’hyperferritinémie chez les patients traités par phlébotomies à l’établissement français du sang (EFS) : résultats de l’étude EMSAI (étude multicentrique sur les patients admis dans un protocole de saignées itératives). Transfus Clin Biol 2017. [DOI: 10.1016/j.tracli.2017.06.112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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12
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Le Tertre M, Ka C, Guellec J, Gourlaouen I, Férec C, Callebaut I, Le Gac G. Deciphering the molecular basis of ferroportin resistance to hepcidin: Structure/function analysis of rare SLC40A1 missense mutations found in suspected hemochromatosis type 4 patients. Transfus Clin Biol 2017; 24:462-467. [PMID: 28826751 DOI: 10.1016/j.tracli.2017.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 07/20/2017] [Indexed: 01/25/2023]
Abstract
Genetic medicine applied to the study of hemochromatosis has identified the systemic loop controlling iron homeostasis, centered on hepcidin-ferroportin interaction. Current challenges are to dissect the molecular pathways underlying liver hepcidin synthesis in response to circulatory iron, HFE, TFR2, HJV, TMPRSS6 and BMP6 functions, and to define the major structural elements of hepcidin-ferroportin interaction. We built a first 3D model of human ferroportin structure, using the crystal structure of EmrD, a bacterial drug efflux transporter of the Major Facilitator Superfamily, as template. The model enabled study of disease-associated mutations, and guided mutagenesis experiments to determine the role of conserved residues in protein stability and iron transport. Results revealed novel amino acids that are critical for the iron export function and the hepcidin-mediated inhibition mechanism: for example, tryptophan 42, localized in the extracellular end of the ferroportin pore and involved in both biological functions. Here, we propose a strategy that is not limited to structure analysis, but integrates information from different sources, including human disease-associated mutations and functional in vitro assays. The first major hypothesis of this PhD thesis is that ferroportin resistance to hepcidin relies on different molecular mechanisms that are critical for ferroportin endocytosis, and include at least three fundamental steps: (i) hepcidin binding to ferroportin, (ii) structural reorganization of the N- and C-ter ferroportin lobes, and (iii) ferroportin ubiquitination.
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Affiliation(s)
- M Le Tertre
- Inserm UMR1078, faculté de médecine et des sciences de la santé, université Bretagne Loire-université de Bretagne Occidentale, IBSAM, IBRBS, 22, rue Camille-Desmoulins, 29200 Brest, France; Laboratory of Excellence GR-Ex, institut Imagine, 24, boulevard du Montparnasse, 75015, Paris, France; Laboratoire de génétique moléculaire et histocompatibilité, hôpital Morvan, CHRU de Brest, 2, avenue Foch, 29200 Brest, France.
| | - C Ka
- Inserm UMR1078, faculté de médecine et des sciences de la santé, université Bretagne Loire-université de Bretagne Occidentale, IBSAM, IBRBS, 22, rue Camille-Desmoulins, 29200 Brest, France; Laboratory of Excellence GR-Ex, institut Imagine, 24, boulevard du Montparnasse, 75015, Paris, France; Laboratoire de génétique moléculaire et histocompatibilité, hôpital Morvan, CHRU de Brest, 2, avenue Foch, 29200 Brest, France
| | - J Guellec
- Inserm UMR1078, faculté de médecine et des sciences de la santé, université Bretagne Loire-université de Bretagne Occidentale, IBSAM, IBRBS, 22, rue Camille-Desmoulins, 29200 Brest, France; Laboratory of Excellence GR-Ex, institut Imagine, 24, boulevard du Montparnasse, 75015, Paris, France; Association Gaetan-Saleun, 29, rue Félix-Le-Dantec, 29200 Brest, France
| | - I Gourlaouen
- Inserm UMR1078, faculté de médecine et des sciences de la santé, université Bretagne Loire-université de Bretagne Occidentale, IBSAM, IBRBS, 22, rue Camille-Desmoulins, 29200 Brest, France; Laboratory of Excellence GR-Ex, institut Imagine, 24, boulevard du Montparnasse, 75015, Paris, France; Établissement français du sang, Bretagne, site de Brest, 46 rue Félix-Le-Dantec, 29200 Brest, France
| | - C Férec
- Inserm UMR1078, faculté de médecine et des sciences de la santé, université Bretagne Loire-université de Bretagne Occidentale, IBSAM, IBRBS, 22, rue Camille-Desmoulins, 29200 Brest, France; Laboratoire de génétique moléculaire et histocompatibilité, hôpital Morvan, CHRU de Brest, 2, avenue Foch, 29200 Brest, France; Établissement français du sang, Bretagne, site de Brest, 46 rue Félix-Le-Dantec, 29200 Brest, France
| | - I Callebaut
- Muséum d'histoire naturelle, IRD UMR 206, case 115, IMPMC, Sorbonne universités-UMR CNRS 7590, UPMC université Paris 06, 4, place Jussieu, 75252 Paris cedex 05, France
| | - G Le Gac
- Inserm UMR1078, faculté de médecine et des sciences de la santé, université Bretagne Loire-université de Bretagne Occidentale, IBSAM, IBRBS, 22, rue Camille-Desmoulins, 29200 Brest, France; Laboratory of Excellence GR-Ex, institut Imagine, 24, boulevard du Montparnasse, 75015, Paris, France; Laboratoire de génétique moléculaire et histocompatibilité, hôpital Morvan, CHRU de Brest, 2, avenue Foch, 29200 Brest, France; Établissement français du sang, Bretagne, site de Brest, 46 rue Félix-Le-Dantec, 29200 Brest, France
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13
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Tchernitchko D, Scotet V, Lefebvre T, L'Hostis C, Gourlaouen I, Merour MC, Rebah K, Peoc'h K, Assari S, Ferec C, Puy H, Le Gac G. GNPAT polymorphism rs11558492 is not associated with increased severity in a large cohort of HFE p.Cys282Tyr homozygous patients. Hepatology 2017; 65:1069-1071. [PMID: 27474861 DOI: 10.1002/hep.28742] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Affiliation(s)
- Dimitri Tchernitchko
- Inserm UMR1149, Center for Inflammation Research, Paris, France; Department of Genetics, Bichat University Hospital, Paris, France; Center for Porphyria Research, Louis Mourier Hospital, Colombes, France; Laboratory of excellence, GR-Ex Paris, France
| | - Virginie Scotet
- Inserm UMR1078, French Blood Agency, Brest, France Gaëtan Saleun Fondation
| | - Thibaud Lefebvre
- Inserm UMR1149, Center for Inflammation Research, Paris, France; Department of Genetics, Bichat University Hospital, Paris, France; Center for Porphyria Research, Louis Mourier Hospital, Colombes, France; Laboratory of excellence, GR-Ex Paris, France
| | - Carine L'Hostis
- Inserm UMR1078, French Blood Agency, Brest, France Gaëtan Saleun Fondation
| | | | | | - Khadidja Rebah
- Inserm UMR1149, Center for Inflammation Research, Paris, France; Department of Genetics, Bichat University Hospital, Paris, France; Center for Porphyria Research, Louis Mourier Hospital, Colombes, France; Laboratory of excellence, GR-Ex Paris, France
| | - Katell Peoc'h
- Inserm UMR1149, Center for Inflammation Research, Paris, France; Department of Genetics, Bichat University Hospital, Paris, France; Center for Porphyria Research, Louis Mourier Hospital, Colombes, France; Laboratory of excellence, GR-Ex Paris, France
| | - Suzanne Assari
- French Blood Agency - Medical Direction, La Plaine Saint-Denis, France
| | - Claude Ferec
- Inserm UMR1078, French Blood Agency, Brest, France Gaëtan Saleun Fondation.,Department of Molecular Genetics and Histocompatibility, University Hospital of Brest, Brest, France
| | - Hervé Puy
- Inserm UMR1149, Center for Inflammation Research, Paris, France; Department of Genetics, Bichat University Hospital, Paris, France; Center for Porphyria Research, Louis Mourier Hospital, Colombes, France; Laboratory of excellence, GR-Ex Paris, France
| | - Gérald Le Gac
- Inserm UMR1078, French Blood Agency, Brest, France Gaëtan Saleun Fondation.,Department of Molecular Genetics and Histocompatibility, University Hospital of Brest, Brest, France
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14
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Le Gac G, Gourlaouen I, Ka C, Férec C. The p.Leu96Pro Missense Mutation in the BMP6 Gene Is Repeatedly Associated With Hyperferritinemia in Patients of French Origin. Gastroenterology 2016; 151:769-70. [PMID: 27590690 DOI: 10.1053/j.gastro.2016.03.054] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Accepted: 03/18/2016] [Indexed: 02/08/2023]
Affiliation(s)
- Gérald Le Gac
- Inserm U1078, Université Bretagne Loire-Université de Bretagne Occidentale, IBSAM, CHRU de Brest, Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Etablissement Français du Sang-Bretagne, Brest, France
| | - Isabelle Gourlaouen
- Inserm U1078, Université Bretagne Loire-Université de Bretagne Occidentale, IBSAM, CHRU de Brest, Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Etablissement Français du Sang-Bretagne, Brest, France
| | - Chandran Ka
- Inserm U1078, Université Bretagne Loire-Université de Bretagne Occidentale, IBSAM, CHRU de Brest, Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Etablissement Français du Sang-Bretagne, Brest, France
| | - Claude Férec
- Inserm U1078, Université Bretagne Loire-Université de Bretagne Occidentale, IBSAM, CHRU de Brest, Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Etablissement Français du Sang-Bretagne, Brest, France
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15
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Saliou P, Le Gac G, Mérour MC, Tripogney C, Chanu B, Gourlaouen I, Nousbaum JB, Férec C, Scotet V. HFE hemochromatosis: influence of dietary iron intake on the iron overload of C282Y homozygous patients. Ann Hematol 2015; 94:1225-7. [DOI: 10.1007/s00277-015-2343-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 02/16/2015] [Indexed: 12/13/2022]
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16
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Ka C, Chen JM, Gourlaouen I, Quemener S, Ronsin C, Massonnet S, Thérond JP, Férec C, Le Gac G. Characterization of the second HFE gross deletion highlights the potential importance of Alu-mediated recombination in haemochromatosis. Br J Haematol 2014; 168:759-62. [PMID: 25284364 DOI: 10.1111/bjh.13145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chandran Ka
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Etablissement Français du Sang - Bretagne, Inserm U1078, Université de Brest, SFR SnInBioS, CHRU de Brest, Brest, France
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17
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Callebaut I, Joubrel R, Pissard S, Kannengiesser C, Gérolami V, Ged C, Cadet E, Cartault F, Ka C, Gourlaouen I, Gourhant L, Oudin C, Goossens M, Grandchamp B, De Verneuil H, Rochette J, Férec C, Le Gac G. Comprehensive functional annotation of 18 missense mutations found in suspected hemochromatosis type 4 patients. Hum Mol Genet 2014; 23:4479-90. [PMID: 24714983 DOI: 10.1093/hmg/ddu160] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Hemochromatosis type 4 is a rare form of primary iron overload transmitted as an autosomal dominant trait caused by mutations in the gene encoding the iron transport protein ferroportin 1 (SLC40A1). SLC40A1 mutations fall into two functional categories (loss- versus gain-of-function) underlying two distinct clinical entities (hemochromatosis type 4A versus type 4B). However, the vast majority of SLC40A1 mutations are rare missense variations, with only a few showing strong evidence of causality. The present study reports the results of an integrated approach collecting genetic and phenotypic data from 44 suspected hemochromatosis type 4 patients, with comprehensive structural and functional annotations. Causality was demonstrated for 10 missense variants, showing a clear dichotomy between the two hemochromatosis type 4 subtypes. Two subgroups of loss-of-function mutations were distinguished: one impairing cell-surface expression and one altering only iron egress. Additionally, a new gain-of-function mutation was identified, and the degradation of ferroportin on hepcidin binding was shown to probably depend on the integrity of a large extracellular loop outside of the hepcidin-binding domain. Eight further missense variations, on the other hand, were shown to have no discernible effects at either protein or RNA level; these were found in apparently isolated patients and were associated with a less severe phenotype. The present findings illustrate the importance of combining in silico and biochemical approaches to fully distinguish pathogenic SLC40A1 mutations from benign variants. This has profound implications for patient management.
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Affiliation(s)
- Isabelle Callebaut
- IMPMC, Sorbonne Universités - UMR CNRS 7590, UPMC Univ Paris 06, Muséum d'Histoire Naturelle, IRD UMR 206, Paris, France
| | - Rozenn Joubrel
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Inserm U1078, Université de Brest, SFR SnInBioS, CHRU de Brest, Etablissement Français du Sang - Bretagne, Brest, France
| | - Serge Pissard
- Laboratoire de Génétique, UPEC (Université Paris Est Creteil), GHU Henri Mondor, Créteil, France
| | - Caroline Kannengiesser
- Hôpital Bichat, Département de Génétique, Inserm U1149 - Center for Research on Inflammation, Université Paris Diderot, AP-HP, Paris, France
| | | | - Cécile Ged
- Inserm U1035, Biothérapies des Maladies Génétiques et Cancers, Université de Bordeaux, CHU de Bordeaux, Pôle de Biologie et Pathologie, Bordeaux, France
| | - Estelle Cadet
- Laboratoire de Génétique Moléculaire, UPJV EA4666, CHU d'Amiens, Amiens, France
| | | | - Chandran Ka
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Inserm U1078, Université de Brest, SFR SnInBioS, CHRU de Brest, Etablissement Français du Sang - Bretagne, Brest, France
| | - Isabelle Gourlaouen
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Inserm U1078, Université de Brest, SFR SnInBioS, CHRU de Brest, Etablissement Français du Sang - Bretagne, Brest, France
| | | | - Claire Oudin
- Hôpital Bichat, Département de Génétique, Inserm U1149 - Center for Research on Inflammation, Université Paris Diderot, AP-HP, Paris, France
| | - Michel Goossens
- Laboratoire de Génétique, UPEC (Université Paris Est Creteil), GHU Henri Mondor, Créteil, France
| | - Bernard Grandchamp
- Hôpital Bichat, Département de Génétique, Inserm U1149 - Center for Research on Inflammation, Université Paris Diderot, AP-HP, Paris, France
| | - Hubert De Verneuil
- Inserm U1035, Biothérapies des Maladies Génétiques et Cancers, Université de Bordeaux, CHU de Bordeaux, Pôle de Biologie et Pathologie, Bordeaux, France
| | - Jacques Rochette
- Laboratoire de Génétique Moléculaire, UPJV EA4666, CHU d'Amiens, Amiens, France
| | - Claude Férec
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Inserm U1078, Université de Brest, SFR SnInBioS, CHRU de Brest, Etablissement Français du Sang - Bretagne, Brest, France
| | - Gérald Le Gac
- Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Inserm U1078, Université de Brest, SFR SnInBioS, CHRU de Brest, Etablissement Français du Sang - Bretagne, Brest, France CHRU de Brest, Inserm CIC0502, Brest, France
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18
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Le Gac G, Ka C, Joubrel R, Gourlaouen I, Lehn P, Mornon JP, Férec C, Callebaut I. Structure-function analysis of the human ferroportin iron exporter (SLC40A1): effect of hemochromatosis type 4 disease mutations and identification of critical residues. Hum Mutat 2013; 34:1371-80. [PMID: 23784628 DOI: 10.1002/humu.22369] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 06/06/2013] [Indexed: 11/06/2022]
Abstract
Ferroportin (SLC40A1) is the only known iron exporter in mammals and is considered a key coordinator of the iron balance between intracellular and systemic iron homeostasis. However, the structural organization of ferroportin in the lipid bilayer remains controversial and very little is known about the mechanism underlying iron egress. In the present study, we have developed an approach based on comparative modeling, which has led to the construction of a model of the three-dimensional (3D) structure of ferroportin by homology to the crystal structure of a Major Facilitator Superfamily member (EmrD). This model predicts atomic details for the organization of ferroportin transmembrane helices and is in agreement with our current understanding of the ferroportin function and its interaction with hepcidin. Using in vitro experiments, we demonstrate that this model can be used to identify novel critical amino acids. In particular, we show that the tryptophan residue 42 (p.Trp42), which is localized within the extracellular end of the ferroportin pore, is likely involved in both the iron export function and in the mechanism of inhibition by hepcidin. Thus, our 3D model provides a new perspective for understanding the molecular basis of ferroportin functions and dysfunctions.
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Affiliation(s)
- Gérald Le Gac
- Inserm UMR1078, Université de Brest, SFR SnInBioS, Centre Hospitalier Régional Universitaire - Laboratoire de Génétique Moléculaire et d'Histocompatibilité, Etablissement Français du Sang - Bretagne, Brest, France
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19
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Cézard C, Rabbind Singh A, Le Gac G, Gourlaouen I, Ferec C, Rochette J. Phenotypic expression of a novel C282Y/R226G compound heterozygous state in HFE hemochromatosis: molecular dynamics and biochemical studies. Blood Cells Mol Dis 2013; 52:27-34. [PMID: 23953397 DOI: 10.1016/j.bcmd.2013.07.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 06/28/2013] [Accepted: 07/05/2013] [Indexed: 11/15/2022]
Abstract
Most adults affected with hereditary hemochromatosis are homozygous for a single point mutation of HFE (p.Cys282Tyr). Apart from the compound heterozygous state for the p.Cys282Tyr mutant and the widespread p.His63Asp variant allele, other rare HFE mutations can be found in trans and may have clinical impact. In the present report we describe the structural and functional consequences of a new mutation, namely the p.Arg226Gly which was inherited in trans with the p.Cys282Tyr allele in a patient affected with a mild iron overload. Because the R226G substitution is located in the vicinity of the normal Cys225S-S282Cys disulfide bond we initially investigated the structure of the variant by molecular dynamics techniques in order to estimate the effect of the mutation on the global structure of HFE domain α3. We found that the solvation free energy, hydrophobicity and formation of salt bridges are slightly modified with the global secondary structure of the α3 domain being conserved. In a previous paper, we demonstrated that the Q283P substitution leads to the loss of the normal Cys225S-S282Cys disulfide bridge. Similar to the Q283P substitution, the R226G substitution does not substitute a residue directly involved in the formation of the disulfide bridge. However, unlike the p.Gln283Pro variant which destroyed the normal disulfide bridge, the R226G mutation does not affect the normal Cys225S-S282Cys bridge. Furthermore based on cell line studies we clearly show that the mutation does not prevent cell surface localization, β2-microglobulin association and binding to transferrin receptor 1. This new compound heterozygous phenotype is very close to those of the C282Y/H63D compound heterozygous patients who display the biochemical hemochromatosis phenotype but with lower body iron stores than C282Y homozygotes. Our results do not exclude unknown genetic and/or metabolic factors that may act synergistically to increase the ferritin level.
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Affiliation(s)
- Christine Cézard
- Laboratoire des Glucides, CNRS FRE 3517, Université de Picardie Jules Verne, Amiens 80037 Cedex 1, France
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Milet J, Le Gac G, Scotet V, Gourlaouen I, Thèze C, Mosser J, Bourgain C, Deugnier Y, Férec C. A common SNP near BMP2 is associated with severity of the iron burden in HFE p.C282Y homozygous patients: A follow-up study. Blood Cells Mol Dis 2010; 44:34-7. [DOI: 10.1016/j.bcmd.2009.10.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2009] [Accepted: 09/23/2009] [Indexed: 12/29/2022]
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Le Gac G, Congiu R, Gourlaouen I, Cau M, Férec C, Melis MA. Homozygous deletion of HFE is the common cause of hemochromatosis in Sardinia. Haematologica 2009; 95:685-7. [PMID: 20007136 DOI: 10.3324/haematol.2009.016816] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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22
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Létocart E, Le Gac G, Majore S, Ka C, Radio FC, Gourlaouen I, De Bernardo C, Férec C, Grammatico P. A novel missense mutation in SLC40A1 results in resistance to hepcidin and confirms the existence of two ferroportin-associated iron overload diseases. Br J Haematol 2009; 147:379-85. [PMID: 19709084 DOI: 10.1111/j.1365-2141.2009.07834.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ferroportin-related iron overload disease differs from haemochromatosis in that it has a dominant mode of inheritance and is usually associated with macrophage iron sequestration. However, it is thought that mutations with opposite effects on protein functions, i.e. loss-of-function versus gain-of-function mutations, are responsible for variable phenotype presentations. The present study investigated the functional relevance of a novel ferroportin variant: the c.1502 A>G transition, which changes amino acid 501 from tyrosine to cysteine (p.Y501C). This novel variant was identified in a pedigree originating from Central Italy and, although an intra-familial phenotype heterogeneity was observed, it co-segregated with an iron overload picture similar to that of the HFE-related typical haemochromatosis. In cultured cells, the p.Y501C mutant protein reached the plasma membrane and retained a full iron export ability. By contrast, it was resistant to inhibition by hepcidin. These findings confirm that certain ferroportin mutations compromise the activity of hepcidin in iron homeostasis, mimicking hepcidin deficiency as described in all types of hemochromatosis.
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Affiliation(s)
- Emilie Létocart
- Inserm U613, Etablissement Français du Sang - Bretagne, Université de Bretagne Occidentale, Brest, France
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23
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Ka C, Le Gac G, Letocart E, Gourlaouen I, Martin B, Férec C. Phenotypic and functional data confirm causality of the recently identified hemojuvelin p.r176c missense mutation. Haematologica 2008; 92:1262-3. [PMID: 17768121 DOI: 10.3324/haematol.11247] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
In the present study, we correlate homozygosity for the very recently identified HJV p.R176C substitution with a juvenile hemochromatosis phenotype. We also show that the p.R176C variant fails to up-regulate the hepcidin promoter activity. Altogether, our results definitively show the R176C amino-acid change to be a novel hemojuvelin loss-of-function mutation.
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24
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Le Gac G, Scotet V, Ka C, Gourlaouen I, Bryckaert L, Jacolot S, Mura C, Férec C. The recently identified type 2A juvenile haemochromatosis gene (HJV), a second candidate modifier of the C282Y homozygous phenotype. Hum Mol Genet 2004; 13:1913-8. [PMID: 15254010 DOI: 10.1093/hmg/ddh206] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The most common form of hereditary haemochromatosis is an adult-onset condition usually associated with the HFE C282Y/C282Y genotype. The phenotypic expression of this genotype is heterogeneous and depends on a complex interplay of genetic and non-genetic factors. The aim of the present study was to determine if mutations in the recently identified HJV gene were associated with more severe iron overload phenotypes in C282Y homozygous patients. From a cohort of 310 C282Y homozygous patients, we found nine (six males and three females) with an additional HJV missense mutation in the heterozygous state (S105L, E302K, N372D, R335Q or the previously described L101P and G320V). The iron indices of eight patients appeared to be more severe than those observed in C282Y homozygous patients of identical sex and similar age ranges. The mean serum ferritin concentration of the six males with an HJV mutation was significantly higher than that of C282Y homozygous males without an additional mutation [2350.3 (sigma=1429.9) versus 1227.2 (sigma=1130.1) microg/l; P=0.0233, Student's t-test]. We have recently reported that mutations in the gene that encodes hepcidin (HAMP) could explain one part of the C282Y/C282Y-related phenotypic heterogeneity by accentuating the iron burden. Our new data reveal that mutations in the HJV gene could be associated with a similar effect. Taken together, these results emphasize that a search for modifier genes could enable us to more precisely distinguish those C282Y homozygous patients with a higher risk to develop a severe iron overload and, consequently, clinical complications.
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