Interaction between methionine synthase isoforms and MMACHC: characterization in cblG-variant, cblG and cblC inherited causes of megaloblastic anaemia
| Autor: | Mihaela Pupavac, Jean-Marc Alberto, François Feillet, David S. Rosenblatt, Brian Fowler, Natacha Dreumont, Jean-Louis Guéant, Nadir T. Mrabet, Jean-Michel Camadro, Justine Flayac, David Coelho, David Watkins, Céline Chéry, Justine Paoli, Ma'atem B. Fofou-Caillierez |
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| Přispěvatelé: | Nutrition-Génétique et Exposition aux Risques Environnementaux (NGERE), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lorraine (UL), Department of Human Genetics [Montréal], McGill University, Institut Jacques Monod (IJM (UMR_7592)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Metabolic Unit, University Children's Hospital, the French minister of Health (for the Reference Centre of inborn metabolism diseases) by Inserm and the Region Lorraine (for Inserm U954) and by Inserm and the Region Lorraine (for Inserm U954), the Swiss National Foundation, McGill University = Université McGill [Montréal, Canada], University of Zurich |
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Models
Molecular 2716 Genetics (clinical) Anemia Megaloblastic 610 Medicine & health Proximity ligation assay Biology 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase Protein Structure Secondary 03 medical and health sciences 0302 clinical medicine 1311 Genetics Hydroxocobalamin Genetics medicine 1312 Molecular Biology Humans Protein Isoforms Cyanocobalamin Methionine synthase Molecular Biology Genetics (clinical) Cells Cultured 030304 developmental biology 0303 health sciences Binding Sites HEK 293 cells Vitamin B 12 Deficiency [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry Molecular Biology/Molecular biology General Medicine Molecular biology MMACHC Molecular Docking Simulation Vitamin B 12 HEK293 Cells Biochemistry [SDV.GEN.GH]Life Sciences [q-bio]/Genetics/Human genetics 10036 Medical Clinic 030220 oncology & carcinogenesis Gene Knockdown Techniques Methylcobalamin RNA splicing biology.protein CBLC Carrier Proteins Oxidoreductases medicine.drug Protein Binding |
| Zdroj: | Human Molecular Genetics Human Molecular Genetics, Oxford University Press (OUP), 2013, 22 (22), pp.4591-601. ⟨10.1093/hmg/ddt308⟩ HUMAN MOLECULAR GENETICS |
| ISSN: | 0964-6906 1460-2083 |
| DOI: | 10.1093/hmg/ddt308⟩ |
| Popis: | International audience; The cblG and cblC disorders of cobalamin (Cbl) metabolism are two inherited causes of megaloblastic anaemia. In cblG, mutations in methionine synthase (MTR) decrease conversion of hydroxocobalamin (HOCbl) to methylcobalamin, while in cblC, mutations in MMACHC disrupt formation of cob(II)alamin (detected as HOCbl). Cases with undetectable methionine synthase (MS) activity are extremely rare and classified as 'cblG-variant'. In four 'cblG-variant' cases, we observed a decreased conversion of cyanocobalamin to HOCbl that is also seen in cblC cases. To explore this observation, we studied the gene defects, splicing products and expression of MS, as well as MS/MMACHC protein interactions in cblG-variant, cblG, cblC and control fibroblasts. We observed a full-size MS encoded by MTR-001 and a 124 kDa truncated MS encoded by MTR-201 in cblG, cblC, control fibroblasts and HEK cells, but only the MTR-201 transcript and inactive truncated MS in cblG-variant cells. Co-immunoprecipitation and proximity ligation assay showed interaction between truncated MS and MMACHC in cblG-variant cells. This interaction decreased 2.2, 1.5 and 5.0-fold in the proximity ligation assay of cblC cells with p.R161Q and p.R206W mutations, and HEK cells with knock down expression of MS by siRNA, respectively, when compared with control cells. In 3D modelling and docking analysis, both truncated and full-size MS provide a loop anchored to MMACHC, which makes contacts with R-161 and R-206 residues. Our data suggest that the interaction of MS with MMACHC may play a role in the regulation of the cellular processing of Cbls that is required for Cbl cofactor synthesis. |
| Databáze: | OpenAIRE |
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