1
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Mendel RR, Schwarz G. The History of Animal and Plant Sulfite Oxidase-A Personal View. Molecules 2023; 28:6998. [PMID: 37836841 PMCID: PMC10574614 DOI: 10.3390/molecules28196998] [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: 09/12/2023] [Revised: 10/06/2023] [Accepted: 10/07/2023] [Indexed: 10/15/2023] Open
Abstract
Sulfite oxidase is one of five molybdenum-containing enzymes known in eukaryotes where it catalyzes the oxidation of sulfite to sulfate. This review covers the history of sulfite oxidase research starting out with the early years of its discovery as a hepatic mitochondrial enzyme in vertebrates, leading to basic biochemical and structural properties that have inspired research for decades. A personal view on sulfite oxidase in plants, that sulfates are assimilated for their de novo synthesis of cysteine, is presented by Ralf Mendel with numerous unexpected findings and unique properties of this single-cofactor sulfite oxidase localized to peroxisomes. Guenter Schwarz connects his research to sulfite oxidase via its deficiency in humans, demonstrating its unique role amongst all molybdenum enzymes in humans. In essence, in both the plant and animal kingdoms, sulfite oxidase represents an important player in redox regulation, signaling and metabolism, thereby connecting sulfur and nitrogen metabolism in multiple ways.
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Affiliation(s)
- Ralf R. Mendel
- Institute of Plant Biology, Technical University Braunschweig, Humboldtstrasse 1, 38106 Braunschweig, Germany
| | - Günter Schwarz
- Institute of Biochemistry, Department of Chemistry & Center for Molecular Medicine, University of Cologne, Zülpicher Strasse 47, 50674 Cologne, Germany;
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2
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Hassan AH, Ihling C, Iacobucci C, Kastritis PL, Sinz A, Kruse T. The structural principles underlying molybdenum insertase complex assembly. Protein Sci 2023; 32:e4753. [PMID: 37572332 PMCID: PMC10461460 DOI: 10.1002/pro.4753] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/16/2023] [Accepted: 08/08/2023] [Indexed: 08/14/2023]
Abstract
Within the cell, the trace element molybdenum (Mo) is only biologically active when complexed either within the nitrogenase-specific FeMo cofactor or within the molybdenum cofactor (Moco). Moco consists of an organic part, called molybdopterin (MPT) and an inorganic part, that is, the Mo-center. The enzyme which catalyzes the Mo-center formation is the molybdenum insertase (Mo-insertase). Mo-insertases consist of two functional domains called G- and E-domain. The G-domain catalyzes the formation of adenylated MPT (MPT-AMP), which is the substrate for the E-domain, that catalyzes the actual molybdate insertion reaction. Though the functions of E- and G-domain have been elucidated to great structural and mechanistic detail, their combined function is poorly characterized. In this work, we describe a structural model of the eukaryotic Mo-insertase Cnx1 complex that was generated based on cross-linking mass spectrometry combined with computational modeling. We revealed Cnx1 to form an asymmetric hexameric complex which allows the E- and G-domain active sites to align in a catalytic productive orientation toward each other.
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Affiliation(s)
- Ahmed H. Hassan
- TU BraunschweigInstitute of Plant BiologyBraunschweigGermany
- Central European Institute of TechnologyMasaryk UniversityBrnoCzech Republic
| | - Christian Ihling
- Department of Pharmaceutical Chemistry & BioanalyticsInstitute of PharmacyHalle (Saale)Germany
- Center for Structural Mass SpectrometryHalle (Saale)Germany
| | - Claudio Iacobucci
- Department of Pharmaceutical Chemistry & BioanalyticsInstitute of PharmacyHalle (Saale)Germany
- Center for Structural Mass SpectrometryHalle (Saale)Germany
- Department of Physical and Chemical SciencesUniversity of L'AquilaL'AquilaItaly
| | - Panagiotis L. Kastritis
- ZIK HALOmem and Institute of Biochemistry and BiotechnologyMartin‐Luther University Halle‐WittenbergHalle (Saale)Germany
| | - Andrea Sinz
- Department of Pharmaceutical Chemistry & BioanalyticsInstitute of PharmacyHalle (Saale)Germany
- Center for Structural Mass SpectrometryHalle (Saale)Germany
| | - Tobias Kruse
- TU BraunschweigInstitute of Plant BiologyBraunschweigGermany
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3
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Foteva V, Fisher JJ, Qiao Y, Smith R. Does the Micronutrient Molybdenum Have a Role in Gestational Complications and Placental Health? Nutrients 2023; 15:3348. [PMID: 37571285 PMCID: PMC10421405 DOI: 10.3390/nu15153348] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/24/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
Molybdenum is an essential trace element for human health and survival, with molybdenum-containing enzymes catalysing multiple reactions in the metabolism of purines, aldehydes, and sulfur-containing amino acids. Recommended daily intakes vary globally, with molybdenum primarily sourced through the diet, and supplementation is not common. Although the benefits of molybdenum as an anti-diabetic and antioxidant inducer have been reported in the literature, there are conflicting data on the benefits of molybdenum for chronic diseases. Overexposure and deficiency can result in adverse health outcomes and mortality, although physiological doses remain largely unexplored in relation to human health. The lack of knowledge surrounding molybdenum intake and the role it plays in physiology is compounded during pregnancy. As pregnancy progresses, micronutrient demand increases, and diet is an established factor in programming gestational outcomes and maternal health. This review summarises the current literature concerning varied recommendations on molybdenum intake, the role of molybdenum and molybdoenzymes in physiology, and the contribution these play in gestational outcomes.
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Affiliation(s)
- Vladimira Foteva
- Mothers and Babies Research Program, Hunter Medical Research Institute, Newcastle, NSW 2305, Australia; (J.J.F.); (R.S.)
- School of Medicine and Public Health, University of Newcastle, Newcastle, NSW 2308, Australia
| | - Joshua J. Fisher
- Mothers and Babies Research Program, Hunter Medical Research Institute, Newcastle, NSW 2305, Australia; (J.J.F.); (R.S.)
- School of Medicine and Public Health, University of Newcastle, Newcastle, NSW 2308, Australia
| | - Yixue Qiao
- Academy of Pharmacy, Xi’an Jiaotong Liverpool University, Suzhou 215000, China;
| | - Roger Smith
- Mothers and Babies Research Program, Hunter Medical Research Institute, Newcastle, NSW 2305, Australia; (J.J.F.); (R.S.)
- School of Medicine and Public Health, University of Newcastle, Newcastle, NSW 2308, Australia
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4
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Automated Image Analysis Reveals Different Localization of Synaptic Gephyrin C4 Splice Variants. eNeuro 2023; 10:ENEURO.0102-22.2022. [PMID: 36543537 PMCID: PMC9831149 DOI: 10.1523/eneuro.0102-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 11/12/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Postsynaptic scaffolding proteins function as central organization hubs, ensuring the synaptic localization of neurotransmitter receptors, trans-synaptic adhesion proteins, and signaling molecules. Gephyrin is the major postsynaptic scaffolding protein at glycinergic and a subset of GABAergic inhibitory synapses. In contrast to cells outside the CNS, where one gephyrin isoform is predominantly expressed, neurons express different splice variants. In this study, we characterized the expression and scaffolding of neuronal gephyrin isoforms differing in the inclusion of the C4 cassettes located in the central C-domain. In hippocampal and cortical neuronal populations, gephyrin P1, lacking additional cassettes, is the most abundantly expressed isoform. In addition, alternative splicing generated isoforms carrying predominantly C4a, and minor amounts of C4c or C4d cassettes. We detected no striking difference in C4 isoform expression between different neuron types and a single neuron can likely express all C4 isoforms. To avoid the cytosolic aggregates that are commonly observed upon exogenous gephyrin expression, we used adeno-associated virus (AAV)-mediated expression to analyze the scaffolding behavior of individual C4 isoforms in murine dissociated hippocampal glutamatergic neurons. While all isoforms showed similar clustering at GABAergic synapses, a thorough quantitative analysis revealed localization differences for the C4c isoform (also known as P2). Specifically, synaptic C4c isoform clusters showed a more distal dendritic localization and reduced occurrence at P1-predominating synapses. Additionally, inhibitory currents displayed faster decay kinetics in the presence of gephyrin C4c compared with P1. Therefore, inhibitory synapse heterogeneity may be influenced, at least in part, by mechanisms relating to C4 cassette splicing.
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5
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Johannes L, Fu CY, Schwarz G. Molybdenum Cofactor Deficiency in Humans. Molecules 2022; 27:6896. [PMID: 36296488 PMCID: PMC9607355 DOI: 10.3390/molecules27206896] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 11/17/2022] Open
Abstract
Molybdenum cofactor (Moco) deficiency (MoCD) is characterized by neonatal-onset myoclonic epileptic encephalopathy and dystonia with cerebral MRI changes similar to hypoxic-ischemic lesions. The molecular cause of the disease is the loss of sulfite oxidase (SOX) activity, one of four Moco-dependent enzymes in men. Accumulating toxic sulfite causes a secondary increase of metabolites such as S-sulfocysteine and thiosulfate as well as a decrease in cysteine and its oxidized form, cystine. Moco is synthesized by a three-step biosynthetic pathway that involves the gene products of MOCS1, MOCS2, MOCS3, and GPHN. Depending on which synthetic step is impaired, MoCD is classified as type A, B, or C. This distinction is relevant for patient management because the metabolic block in MoCD type A can be circumvented by administering cyclic pyranopterin monophosphate (cPMP). Substitution therapy with cPMP is highly effective in reducing sulfite toxicity and restoring biochemical homeostasis, while the clinical outcome critically depends on the degree of brain injury prior to the start of treatment. In the absence of a specific treatment for MoCD type B/C and SOX deficiency, we summarize recent progress in our understanding of the underlying metabolic changes in cysteine homeostasis and propose novel therapeutic interventions to circumvent those pathological changes.
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Affiliation(s)
| | | | - Günter Schwarz
- Institute of Biochemistry, Department of Chemistry & Center for Molecular Medicine Cologne, University of Cologne, 50674 Cologne, Germany
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6
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Pristup J, Schaeffeler E, Arjune S, Hofmann U, Santamaria-Araujo JA, Leuthold P, Friedrich N, Nauck M, Mayr S, Haag M, Muerdter T, Marner FJ, Relling MV, Evans WE, Schwarz G, Schwab M. Molybdenum Cofactor Catabolism Unravels the Physiological Role of the Drug Metabolizing Enzyme Thiopurine S-Methyltransferase. Clin Pharmacol Ther 2022; 112:808-816. [PMID: 35538648 PMCID: PMC9474665 DOI: 10.1002/cpt.2637] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 05/04/2022] [Indexed: 12/14/2022]
Abstract
Therapy of molybdenum cofactor (Moco) deficiency has received US Food and Drug Administration (FDA) approval in 2021. Whereas urothione, the urinary excreted catabolite of Moco, is used as diagnostic biomarker for Moco-deficiency, its catabolic pathway remains unknown. Here, we identified the urothione-synthesizing methyltransferase using mouse liver tissue by anion exchange/size exclusion chromatography and peptide mass fingerprinting. We show that the catabolic Moco S-methylating enzyme corresponds to thiopurine S-methyltransferase (TPMT), a highly polymorphic drug-metabolizing enzyme associated with drug-related hematotoxicity but unknown physiological role. Urothione synthesis was investigated in vitro using recombinantly expressed human TPMT protein, liver lysates from Tpmt wild-type and knock-out (Tpmt-/- ) mice as well as human liver cytosol. Urothione levels were quantified by liquid-chromatography tandem mass spectrometry in the kidneys and urine of mice. TPMT-genotype/phenotype and excretion levels of urothione were investigated in human samples and validated in an independent population-based study. As Moco provides a physiological substrate (thiopterin) of TPMT, thiopterin-methylating activity was associated with TPMT activity determined with its drug substrate (6-thioguanin) in mice and humans. Urothione concentration was extremely low in the kidneys and urine of Tpmt-/- mice. Urinary urothione concentration in TPMT-deficient patients depends on common TPMT polymorphisms, with extremely low levels in homozygous variant carriers (TPMT*3A/*3A) but normal levels in compound heterozygous carriers (TPMT*3A/*3C) as validated in the population-based study. Our work newly identified an endogenous substrate for TPMT and shows an unprecedented link between Moco catabolism and drug metabolism. Moreover, the TPMT example indicates that phenotypic consequences of genetic polymorphisms may differ between drug- and endogenous substrates.
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Affiliation(s)
- Julika Pristup
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Elke Schaeffeler
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, 70376 Stuttgart, Germany
- Cluster of Excellence iFIT (EXC2180) "Image-Guided and Functionally Instructed Tumor Therapies", University of Tuebingen, 72076 Tuebingen, Germany
| | - Sita Arjune
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Ute Hofmann
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, 70376 Stuttgart, Germany
| | | | - Patrick Leuthold
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, 70376 Stuttgart, Germany
| | - Nele Friedrich
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, 17475 Greifswald, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Greifswald, University Medicine, 17475 Greifswald, Germany
| | - Matthias Nauck
- Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, 17475 Greifswald, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Greifswald, University Medicine, 17475 Greifswald, Germany
| | - Simon Mayr
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Mathias Haag
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, 70376 Stuttgart, Germany
| | - Thomas Muerdter
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, 70376 Stuttgart, Germany
| | - Franz-Josef Marner
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Mary V Relling
- Hematological Malignancies Program, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678, USA
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678, USA
| | - William E Evans
- Hematological Malignancies Program, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678, USA
- Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee 38105-3678, USA
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, 70376 Stuttgart, Germany
- Cluster of Excellence iFIT (EXC2180) "Image-Guided and Functionally Instructed Tumor Therapies", University of Tuebingen, 72076 Tuebingen, Germany
- Departments of Clinical Pharmacology, Pharmacy and Biochemistry, University Tuebingen, 72076 Tuebingen, Germany
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7
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Kaczmarek AT, Bender D, Gehling T, Kohl JB, Daimagüler HS, Santamaria-Araujo JA, Liebau MC, Koy A, Cirak S, Schwarz G. A defect in molybdenum cofactor binding causes an attenuated form of sulfite oxidase deficiency. J Inherit Metab Dis 2022; 45:169-182. [PMID: 34741542 DOI: 10.1002/jimd.12454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 11/03/2021] [Accepted: 11/04/2021] [Indexed: 11/11/2022]
Abstract
Isolated sulfite oxidase deficiency (ISOD) is a rare recessive and infantile lethal metabolic disorder, which is caused by functional loss of sulfite oxidase (SO) due to mutations of the SUOX gene. SO is a mitochondrially localized molybdenum cofactor (Moco)- and heme-dependent enzyme, which catalyzes the vital oxidation of toxic sulfite to sulfate. Accumulation of sulfite and sulfite-related metabolites such as S-sulfocysteine (SSC) are drivers of severe neurodegeneration leading to early childhood death in the majority of ISOD patients. Full functionality of SO is dependent on correct insertion of the heme cofactor and Moco, which is controlled by a highly orchestrated maturation process. This maturation involves the translation in the cytosol, import into the intermembrane space (IMS) of mitochondria, cleavage of the mitochondrial targeting sequence, and insertion of both cofactors. Moco insertion has proven as the crucial step in this maturation process, which enables the correct folding of the homodimer and traps SO in the IMS. Here, we report on a novel ISOD patient presented at 17 months of age carrying the homozygous mutation NM_001032386.2 (SUOX):c.1097G > A, which results in the expression of SO variant R366H. Our studies show that histidine substitution of Arg366, which is involved in coordination of the Moco-phosphate, causes a severe reduction in Moco insertion efficacy in vitro and in vivo. Expression of R366H in HEK SUOX-/- cells mimics the phenotype of patient's fibroblasts, representing a loss of SO expression and specific activity. Our studies disclose a general paradigm for a kinetic defect in Moco insertion into SO caused by residues involved in Moco coordination resulting in the case of R366H in an attenuated form of ISOD.
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Affiliation(s)
- Alexander Tobias Kaczmarek
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne, Germany
- Centre for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Daniel Bender
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne, Germany
- Department of Pediatric Neurology, University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Titus Gehling
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne, Germany
| | - Joshua Benedict Kohl
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne, Germany
| | - Hülya-Sevcan Daimagüler
- Centre for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- Department of Pediatrics, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
| | | | - Max Christoph Liebau
- Centre for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- Department of Pediatrics, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Anne Koy
- Department of Pediatrics, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Sebahattin Cirak
- Centre for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- Department of Pediatrics, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Guenter Schwarz
- Department of Chemistry, Institute of Biochemistry, University of Cologne, Cologne, Germany
- Centre for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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8
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Macha A, Liebsch F, Fricke S, Hetsch F, Neuser F, Johannes L, Kress V, Djémié T, Santamaria-Araujo JA, Vilain C, Aeby A, Van Bogaert P, Dejanovic B, Weckhuysen S, Meier JC, Schwarz G. Bi-allelic gephyrin variants impair GABAergic inhibition in a patient with epileptic encephalopathy. Hum Mol Genet 2021; 31:901-913. [PMID: 34617111 DOI: 10.1093/hmg/ddab298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 09/10/2021] [Accepted: 09/22/2021] [Indexed: 11/12/2022] Open
Abstract
Synaptic inhibition is essential for shaping the dynamics of neuronal networks, and aberrant inhibition is linked to epilepsy. Gephyrin (Geph) is the principal scaffolding protein at inhibitory synapses and is essential for postsynaptic clustering of glycine (GlyRs) and GABA type A receptors (GABAARs). Consequently, gephyrin is crucial for maintaining the relationship between excitation and inhibition in normal brain function and mutations in the gephyrin gene (GPHN) are associated with neurodevelopmental disorders and epilepsy. We identified bi-allelic variants in the GPHN gene, namely the missense mutation c.1264G > A and splice acceptor variant c.1315-2A > G, in a patient with developmental and epileptic encephalopathy (DEE). We demonstrate that the splice acceptor variant leads to nonsense-mediated mRNA decay (NMD). Furthermore, the missense variant (D422N) alters gephyrin structure, as examined by analytical size exclusion chromatography and CD-spectroscopy, thus leading to reduced receptor clustering and sensitivity towards calpain-mediated cleavage. Additionally, both alterations contribute to an observed reduction of inhibitory signal transmission in neurons, which likely contributes to the pathological encephalopathy.
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Affiliation(s)
- Arthur Macha
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Filip Liebsch
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Steffen Fricke
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.,Institute for Pathophysiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Florian Hetsch
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Franziska Neuser
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Lena Johannes
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Vanessa Kress
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Tania Djémié
- Applied & Translational Neurogenomics Group, VIB-Center for Molecular Genetics, VIB, Antwerp, Belgium
| | - Jose A Santamaria-Araujo
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Catheline Vilain
- Department of Genetics, Hôpital Universitaire des Enfants Reine Fabiola, ULB Center of Human Genetics, Université Libre de Bruxelles, Brussels, Belgium.,Department of Genetics, Hôpital Erasme, ULB Center of Human Genetics, Université Libre de Bruxelles, Brussels, Belgium.,Interuniversity Institute of Bioinformatics in Brussels, Université Libre de Bruxelles, Brussels, Belgium
| | - Alec Aeby
- Pediatric Neurology, Queen Fabiola Children Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Patrick Van Bogaert
- Departement of Pediatric Neurology, CHU d'Angers, and Laboratoire Angevin de Recherche en Ingénierie des Systèmes (LARIS), Université d'Angers, France
| | - Borislav Dejanovic
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Sarah Weckhuysen
- Applied & Translational Neurogenomics Group, VIB-Center for Molecular Genetics, VIB, Antwerp, Belgium.,Translational Neurosciences, Faculty of Medicine and Health Science, University of Antwerp, Antwerp, Belgium.,Neurology Department, University Hospital Antwerp, Antwerp, Belgium
| | - Jochen C Meier
- Division Cell Physiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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9
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Mayr SJ, Mendel RR, Schwarz G. Molybdenum cofactor biology, evolution and deficiency. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118883. [PMID: 33017596 DOI: 10.1016/j.bbamcr.2020.118883] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 12/14/2022]
Abstract
The molybdenum cofactor (Moco) represents an ancient metal‑sulfur cofactor, which participates as catalyst in carbon, nitrogen and sulfur cycles, both on individual and global scale. Given the diversity of biological processes dependent on Moco and their evolutionary age, Moco is traced back to the last universal common ancestor (LUCA), while Moco biosynthetic genes underwent significant changes through evolution and acquired additional functions. In this review, focused on eukaryotic Moco biology, we elucidate the benefits of gene fusions on Moco biosynthesis and beyond. While originally the gene fusions were driven by biosynthetic advantages such as coordinated expression of functionally related proteins and product/substrate channeling, they also served as origin for the development of novel functions. Today, Moco biosynthetic genes are involved in a multitude of cellular processes and loss of the according gene products result in severe disorders, both related to Moco biosynthesis and secondary enzyme functions.
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Affiliation(s)
- Simon J Mayr
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine, University of Cologne, Zuelpicher Str. 47, 50674 Koeln, Germany
| | - Ralf-R Mendel
- Institute of Plant Biology, Braunschweig University of Technology, Humboldtstr. 1, 38106 Braunschweig, Germany
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine, University of Cologne, Zuelpicher Str. 47, 50674 Koeln, Germany.
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10
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The Requirement of Inorganic Fe-S Clusters for the Biosynthesis of the Organometallic Molybdenum Cofactor. INORGANICS 2020. [DOI: 10.3390/inorganics8070043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Iron-sulfur (Fe-S) clusters are essential protein cofactors. In enzymes, they are present either in the rhombic [2Fe-2S] or the cubic [4Fe-4S] form, where they are involved in catalysis and electron transfer and in the biosynthesis of metal-containing prosthetic groups like the molybdenum cofactor (Moco). Here, we give an overview of the assembly of Fe-S clusters in bacteria and humans and present their connection to the Moco biosynthesis pathway. In all organisms, Fe-S cluster assembly starts with the abstraction of sulfur from l-cysteine and its transfer to a scaffold protein. After formation, Fe-S clusters are transferred to carrier proteins that insert them into recipient apo-proteins. In eukaryotes like humans and plants, Fe-S cluster assembly takes place both in mitochondria and in the cytosol. Both Moco biosynthesis and Fe-S cluster assembly are highly conserved among all kingdoms of life. Moco is a tricyclic pterin compound with molybdenum coordinated through its unique dithiolene group. Moco biosynthesis begins in the mitochondria in a Fe-S cluster dependent step involving radical/S-adenosylmethionine (SAM) chemistry. An intermediate is transferred to the cytosol where the dithiolene group is formed, to which molybdenum is finally added. Further connections between Fe-S cluster assembly and Moco biosynthesis are discussed in detail.
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11
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Mayr SJ, Röper J, Schwarz G. Alternative splicing of the bicistronic gene molybdenum cofactor synthesis 1 ( MOCS1) uncovers a novel mitochondrial protein maturation mechanism. J Biol Chem 2020; 295:3029-3039. [PMID: 31996372 DOI: 10.1074/jbc.ra119.010720] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 01/22/2020] [Indexed: 01/30/2023] Open
Abstract
Molybdenum cofactor (Moco) biosynthesis is a highly conserved multistep pathway. The first step, the conversion of GTP to cyclic pyranopterin monophosphate (cPMP), requires the bicistronic gene molybdenum cofactor synthesis 1 (MOCS1). Alternative splicing of MOCS1 within exons 1 and 9 produces four different N-terminal and three different C-terminal products (type I-III). Type I splicing results in bicistronic transcripts with two open reading frames, of which only the first, MOCS1A, is translated, whereas type II/III splicing produces MOCS1AB proteins. Here, we first report the cellular localization of alternatively spliced human MOCS1 proteins. Using fluorescence microscopy, fluorescence spectroscopy, and cell fractionation experiments, we found that depending on the alternative splicing of exon 1, type I splice variants (MOCS1A) either localize to the mitochondrial matrix (exon 1a) or remain cytosolic (exon 1b). MOCS1A proteins required exon 1a for mitochondrial translocation, but fluorescence microscopy of MOCS1AB variants (types II and III) revealed that they were targeted to mitochondria independently of exon 1 splicing. In the latter case, cell fractionation experiments displayed that mitochondrial matrix import was facilitated via an internal motif overriding the N-terminal targeting signal. Within mitochondria, MOCS1AB underwent proteolytic cleavage resulting in mitochondrial matrix localization of the MOCS1B domain. In conclusion, MOCS1 produces two functional proteins, MOCS1A and MOCS1B, which follow different translocation routes before mitochondrial matrix import for cPMP biosynthesis involving both proteins. MOCS1 protein maturation provides a novel alternative splicing mechanism that ensures the coordinated mitochondrial targeting of two functionally related proteins encoded by a single gene.
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Affiliation(s)
- Simon J Mayr
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Juliane Röper
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, University of Cologne, 50674 Cologne, Germany; Center for Molecular Medicine, University of Cologne, 5931 Cologne, Germany.
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12
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Bender D, Kaczmarek AT, Santamaria-Araujo JA, Stueve B, Waltz S, Bartsch D, Kurian L, Cirak S, Schwarz G. Impaired mitochondrial maturation of sulfite oxidase in a patient with severe sulfite oxidase deficiency. Hum Mol Genet 2019; 28:2885-2899. [DOI: 10.1093/hmg/ddz109] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 04/09/2019] [Accepted: 05/07/2019] [Indexed: 01/24/2023] Open
Abstract
AbstractSulfite oxidase (SO) is encoded by the nuclear SUOX gene and catalyzes the final step in cysteine catabolism thereby oxidizing sulfite to sulfate. Oxidation of sulfite is dependent on two cofactors within SO, a heme and the molybdenum cofactor (Moco), the latter forming the catalytic site of sulfite oxidation. SO localizes to the intermembrane space of mitochondria where both—pre-SO processing and cofactor insertion—are essential steps during SO maturation. Isolated SO deficiency (iSOD) is a rare inborn error of metabolism caused by mutations in the SUOX gene that lead to non-functional SO. ISOD is characterized by rapidly progressive neurodegeneration and death in early infancy. We diagnosed an iSOD patient with homozygous mutation of SUOX at c.1084G>A replacing Gly362 to serine. To understand the mechanism of disease, we expressed patient-derived G362S SO in Escherichia coli and surprisingly found full catalytic activity, while in patient fibroblasts no SO activity was detected, suggesting differences between bacterial and human expression. Moco reconstitution of apo-G362S SO was found to be approximately 90-fold reduced in comparison to apo-WT SO in vitro. In line, levels of SO-bound Moco in cells overexpressing G362S SO were significantly reduced compared to cells expressing WT SO providing evidence for compromised maturation of G362S SO in cellulo. Addition of molybdate to culture medium partially rescued impaired Moco binding of G362S SO and restored SO activity in patient fibroblasts. Thus, this study demonstrates the importance of the orchestrated maturation of SO and provides a first case of Moco-responsive iSOD.
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Affiliation(s)
- Daniel Bender
- Department of Chemistry, Institute for Biochemistry, University of Cologne, 50674 Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne Germany
| | - Alexander Tobias Kaczmarek
- Department of Chemistry, Institute for Biochemistry, University of Cologne, 50674 Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne Germany
| | | | - Burkard Stueve
- Abteilung für Kinderneurologie, Epileptologie und Sozialpädiatrie, Kliniken Köln, Kinderkrankenhaus, 51058 Cologne, Germany
| | - Stephan Waltz
- Abteilung für Kinderneurologie, Epileptologie und Sozialpädiatrie, Kliniken Köln, Kinderkrankenhaus, 51058 Cologne, Germany
| | - Deniz Bartsch
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne Germany
| | - Leo Kurian
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne Germany
| | - Sebahattin Cirak
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne Germany
- Klinik für Kinderheilkunde und Jugendmedizin, Uniklinikum Köln, 50937 Cologne, Germany
| | - Guenter Schwarz
- Department of Chemistry, Institute for Biochemistry, University of Cologne, 50674 Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, 50931 Cologne Germany
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13
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Neukranz Y, Kotter A, Beilschmidt L, Marelja Z, Helm M, Gräf R, Leimkühler S. Analysis of the Cellular Roles of MOCS3 Identifies a MOCS3-Independent Localization of NFS1 at the Tips of the Centrosome. Biochemistry 2019; 58:1786-1798. [PMID: 30817134 DOI: 10.1021/acs.biochem.8b01160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The deficiency of the molybdenum cofactor (Moco) is an autosomal recessive disease, which leads to the loss of activity of all molybdoenzymes in humans with sulfite oxidase being the essential protein. Moco deficiency generally results in death in early childhood. Moco is a sulfur-containing cofactor synthesized in the cytosol with the sulfur being provided by a sulfur relay system composed of the l-cysteine desulfurase NFS1, MOCS3, and MOCS2A. Human MOCS3 is a dual-function protein that was shown to play an important role in Moco biosynthesis and in the mcm5s2U thio modifications of nucleosides in cytosolic tRNAs for Lys, Gln, and Glu. In this study, we constructed a homozygous MOCS3 knockout in HEK293T cells using the CRISPR/Cas9 system. The effects caused by the absence of MOCS3 were analyzed in detail. We show that sulfite oxidase activity was almost completely abolished, on the basis of the absence of Moco in these cells. In addition, mcm5s2U thio-modified tRNAs were not detectable. Because the l-cysteine desulfurase NFS1 was shown to act as a sulfur donor for MOCS3 in the cytosol, we additionally investigated the impact of a MOCS3 knockout on the cellular localization of NFS1. By different methods, we identified a MOCS3-independent novel localization of NFS1 at the centrosome.
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Affiliation(s)
| | - Annika Kotter
- Institute of Pharmacy and Biochemistry , Johannes Gutenberg-Universität Mainz , 55128 Mainz , Germany
| | | | | | - Mark Helm
- Institute of Pharmacy and Biochemistry , Johannes Gutenberg-Universität Mainz , 55128 Mainz , Germany
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14
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Development of a rapid UPLC–MS/MS determination of urine sulfocysteine for diagnosis of sulfocysteinuria and molybdenum co-factor deficiencies. Bioanalysis 2018; 10:747-756. [DOI: 10.4155/bio-2017-0278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Aim: Molybdenum co-factor deficiencies and isolated sulfite oxidase deficiency are rare autosomal recessively inherited diseases characterized by severe psychomotor impairment, intractable seizures, dislocated lens and dysmorphic facial features. The biochemical diagnosis of these diseases requires the determination of urine sulfocysteine. Materials & methods: Urine sulfocysteine was quantified by an ultra-high performance liquid chromatography–MS/MS assay. The method was validated for linearity, accuracy, precision, recovery and stability. Results & conclusion: Total imprecision of accuracy was less than 6%. Intra-assay and inter-assay precisions were less than 5%. The recovery was higher than 98%. The method is inexpensive, fast, accurate and has been successfully used for identifying five molybdenum co-factor deficient and six sulfite oxidase deficient patients since deployed.
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15
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Mayr SJ, Sass JO, Vry J, Kirschner J, Mader I, Hövener JB, Reiss J, Santamaria-Araujo JA, Schwarz G, Grünert SC. A mild case of molybdenum cofactor deficiency defines an alternative route of MOCS1 protein maturation. J Inherit Metab Dis 2018; 41:187-196. [PMID: 29368224 DOI: 10.1007/s10545-018-0138-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/29/2017] [Accepted: 01/04/2018] [Indexed: 02/07/2023]
Abstract
Molybdenum cofactor deficiency is an autosomal recessive inborn error of metabolism, which results from mutations in genes involved in Moco biosynthesis. Moco serves as a cofactor of several enzymes, including sulfite oxidase. MoCD is clinically characterized by intractable seizures and severe, rapidly progressing neurodegeneration leading to death in early childhood in the majority of known cases. Here we report a patient with an unusual late disease onset and mild phenotype, characterized by a lack of seizures, normal early development, a decline triggered by febrile illness and a subsequent dystonic movement disorder. Genetic analysis revealed a homozygous c.1338delG MOCS1 mutation causing a frameshift (p.S442fs) with a premature termination of the MOCS1AB translation product at position 477 lacking the entire MOCS1B domain. Surprisingly, urine analysis detected trace amounts (1% of control) of the Moco degradation product urothione, suggesting a residual Moco synthesis in the patient, which was consistent with the mild clinical presentation. Therefore, we performed bioinformatic analysis of the patient's mutated MOCS1 transcript and found a potential Kozak-sequence downstream of the mutation site providing the possibility of an independent expression of a MOCS1B protein. Following the expression of the patient's MOCS1 cDNA in HEK293 cells we detected two proteins: a truncated MOCS1AB protein and a 22.4 kDa protein representing MOCS1B. Functional studies of both proteins confirmed activity of MOCS1B, but not of the truncated MOCS1AB. This finding demonstrates an unusual mechanism of translation re-initiation in the MOCS1 transcript, which results in trace amounts of functional MOCS1B protein being sufficient to partially protect the patient from the most severe symptoms of MoCD.
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Affiliation(s)
- Simon Julius Mayr
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Zülpicher Str. 47, 50674, Köln, Germany
| | - Jörn Oliver Sass
- Bioanalytics & Biochemistry, Department of Natural Science, Bonn-Rhein Sieg University of Applied Sciences, Rheinbach, Germany
| | - Julia Vry
- Department of Neuropediatrics and Muscle Disorders, Faculty of Medicine, Medical Center - University of Freiburg, Freiburg, Germany
| | - Janbernd Kirschner
- Department of Neuropediatrics and Muscle Disorders, Faculty of Medicine, Medical Center - University of Freiburg, Freiburg, Germany
| | - Irina Mader
- Faculty of Medicine, Department of Neuroradiology, University of Freiburg, Freiburg, Germany
| | - Jan-Bernd Hövener
- Department of Radiology, Medical Physics, Faculty of Medicine, Medical Center - University of Freiburg, University of Freiburg, Freiburg, Germany
- Section for Biomedical Imaging and MOIN CC, University Medical Center Schleswig Holstein, University of Kiel, Kiel, Germany
| | - Jochen Reiss
- Institut für Humangenetik, Universität Göttingen, Göttingen, Germany
| | - José Angel Santamaria-Araujo
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Zülpicher Str. 47, 50674, Köln, Germany
| | - Günter Schwarz
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Zülpicher Str. 47, 50674, Köln, Germany.
- Center for Molecular Medicine Cologne), University of Cologne, Cologne, Germany.
| | - Sarah Catharina Grünert
- Department of General Pediatrics, Adolescent Medicine and Neonatology, Faculty of Medicine, Medical Center - University of Freiburg, Mathildenstr. 1, 79106, Freiburg, Germany.
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16
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Sequences Flanking the Gephyrin-Binding Site of GlyRβ Tune Receptor Stabilization at Synapses. eNeuro 2018; 5:eN-NWR-0042-17. [PMID: 29464196 PMCID: PMC5818551 DOI: 10.1523/eneuro.0042-17.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 12/26/2017] [Accepted: 01/15/2018] [Indexed: 12/18/2022] Open
Abstract
The efficacy of synaptic transmission is determined by the number of neurotransmitter receptors at synapses. Their recruitment depends upon the availability of postsynaptic scaffolding molecules that interact with specific binding sequences of the receptor. At inhibitory synapses, gephyrin is the major scaffold protein that mediates the accumulation of heteromeric glycine receptors (GlyRs) via the cytoplasmic loop in the β-subunit (β-loop). This binding involves high- and low-affinity interactions, but the molecular mechanism of this bimodal binding and its implication in GlyR stabilization at synapses remain unknown. We have approached this question using a combination of quantitative biochemical tools and high-density single molecule tracking in cultured rat spinal cord neurons. The high-affinity binding site could be identified and was shown to rely on the formation of a 310-helix C-terminal to the β-loop core gephyrin-binding motif. This site plays a structural role in shaping the core motif and represents the major contributor to the synaptic confinement of GlyRs by gephyrin. The N-terminal flanking sequence promotes lower affinity interactions by occupying newly identified binding sites on gephyrin. Despite its low affinity, this binding site plays a modulatory role in tuning the mobility of the receptor. Together, the GlyR β-loop sequences flanking the core-binding site differentially regulate the affinity of the receptor for gephyrin and its trapping at synapses. Our experimental approach thus bridges the gap between thermodynamic aspects of receptor-scaffold interactions and functional receptor stabilization at synapses in living cells.
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17
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Kumar A, Dejanovic B, Hetsch F, Semtner M, Fusca D, Arjune S, Santamaria-Araujo JA, Winkelmann A, Ayton S, Bush AI, Kloppenburg P, Meier JC, Schwarz G, Belaidi AA. S-sulfocysteine/NMDA receptor-dependent signaling underlies neurodegeneration in molybdenum cofactor deficiency. J Clin Invest 2017; 127:4365-4378. [PMID: 29106383 DOI: 10.1172/jci89885] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 09/26/2017] [Indexed: 02/06/2023] Open
Abstract
Molybdenum cofactor deficiency (MoCD) is an autosomal recessive inborn error of metabolism characterized by neurodegeneration and death in early childhood. The rapid and progressive neurodegeneration in MoCD presents a major clinical challenge and may relate to the poor understanding of the molecular mechanisms involved. Recently, we reported that treating patients with cyclic pyranopterin monophosphate (cPMP) is a successful therapy for a subset of infants with MoCD and prevents irreversible brain damage. Here, we studied S-sulfocysteine (SSC), a structural analog of glutamate that accumulates in the plasma and urine of patients with MoCD, and demonstrated that it acts as an N-methyl D-aspartate receptor (NMDA-R) agonist, leading to calcium influx and downstream cell signaling events and neurotoxicity. SSC treatment activated the protease calpain, and calpain-dependent degradation of the inhibitory synaptic protein gephyrin subsequently exacerbated SSC-mediated excitotoxicity and promoted loss of GABAergic synapses. Pharmacological blockade of NMDA-R, calcium influx, or calpain activity abolished SSC and glutamate neurotoxicity in primary murine neurons. Finally, the NMDA-R antagonist memantine was protective against the manifestation of symptoms in a tungstate-induced MoCD mouse model. These findings demonstrate that SSC drives excitotoxic neurodegeneration in MoCD and introduce NMDA-R antagonists as potential therapeutics for this fatal disease.
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Affiliation(s)
- Avadh Kumar
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Borislav Dejanovic
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Florian Hetsch
- TU Braunschweig, Zoological Institute, Division of Cell Physiology, Braunschweig, Germany
| | - Marcus Semtner
- Cellular Neurosciences, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Debora Fusca
- Biocenter, Institute for Zoology, University of Cologne, Cologne, Germany
| | - Sita Arjune
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Jose Angel Santamaria-Araujo
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Aline Winkelmann
- TU Braunschweig, Zoological Institute, Division of Cell Physiology, Braunschweig, Germany.,Biocenter, Institute for Zoology, University of Cologne, Cologne, Germany
| | - Scott Ayton
- The Florey Institute for Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Ashley I Bush
- The Florey Institute for Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Peter Kloppenburg
- Biocenter, Institute for Zoology, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Jochen C Meier
- TU Braunschweig, Zoological Institute, Division of Cell Physiology, Braunschweig, Germany
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Abdel Ali Belaidi
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,The Florey Institute for Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
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18
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Kalimuthu P, Belaidi AA, Schwarz G, Bernhardt PV. Chitosan-Promoted Direct Electrochemistry of Human Sulfite Oxidase. J Phys Chem B 2017; 121:9149-9159. [DOI: 10.1021/acs.jpcb.7b06712] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Palraj Kalimuthu
- School
of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, 4072, Australia
| | - Abdel A. Belaidi
- Department
of Chemistry and Center for Molecular Medicine, Institute of Biochemistry, Cologne University, Zülicher Strasse 47, 50674 Köln, Germany
- The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Guenter Schwarz
- Department
of Chemistry and Center for Molecular Medicine, Institute of Biochemistry, Cologne University, Zülicher Strasse 47, 50674 Köln, Germany
| | - Paul V. Bernhardt
- School
of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, 4072, Australia
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19
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Leimkühler S. Shared function and moonlighting proteins in molybdenum cofactor biosynthesis. Biol Chem 2017; 398:1009-1026. [PMID: 28284029 DOI: 10.1515/hsz-2017-0110] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/03/2017] [Indexed: 11/15/2022]
Abstract
The biosynthesis of the molybdenum cofactor (Moco) is a highly conserved pathway in bacteria, archaea and eukaryotes. The molybdenum atom in Moco-containing enzymes is coordinated to the dithiolene group of a tricyclic pyranopterin monophosphate cofactor. The biosynthesis of Moco can be divided into three conserved steps, with a fourth present only in bacteria and archaea: (1) formation of cyclic pyranopterin monophosphate, (2) formation of molybdopterin (MPT), (3) insertion of molybdenum into MPT to form Mo-MPT, and (4) additional modification of Mo-MPT in bacteria with the attachment of a GMP or CMP nucleotide, forming the dinucleotide variants of Moco. While the proteins involved in the catalytic reaction of each step of Moco biosynthesis are highly conserved among the Phyla, a surprising link to other cellular pathways has been identified by recent discoveries. In particular, the pathways for FeS cluster assembly and thio-modifications of tRNA are connected to Moco biosynthesis by sharing the same protein components. Further, proteins involved in Moco biosynthesis are not only shared with other pathways, but additionally have moonlighting roles. This review gives an overview of Moco biosynthesis in bacteria and humans and highlights the shared function and moonlighting roles of the participating proteins.
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20
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Ranft J, Almeida LG, Rodriguez PC, Triller A, Hakim V. An aggregation-removal model for the formation and size determination of post-synaptic scaffold domains. PLoS Comput Biol 2017; 13:e1005516. [PMID: 28437460 PMCID: PMC5421815 DOI: 10.1371/journal.pcbi.1005516] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 05/08/2017] [Accepted: 04/11/2017] [Indexed: 11/30/2022] Open
Abstract
The formation and stability of synapses are key questions in neuroscience. Post-synaptic domains have been classically conceived as resulting from local insertion and turnover of proteins at the synapse. However, insertion is likely to occur outside the post-synaptic domains and advances in single-molecule imaging have shown that proteins diffuse in the plane of the membrane prior to their accumulation at synapses. We quantitatively investigated this scenario using computer simulations and mathematical analysis, taking for definiteness the specific case of inhibitory synapse components, i.e., the glycine receptor (GlyR) and the associated gephyrin scaffolding protein. The observed domain sizes of scaffold clusters can be explained by a dynamic balance between the aggregation of gephyrin proteins diffusing while bound to GlyR and their turnover at the neuron membrane. We also predict the existence of extrasynaptic clusters with a characteristic size distribution that significantly contribute to the size fluctuations of synaptic domains. New super-resolution data for gephyrin proteins established the existence of extrasynaptic clusters the sizes of which are consistent with the model predictions in a range of model parameters. At a general level, our results highlight aggregation with removal as a non-equilibrium phase separation which produces structures of tunable size. Synapses mediate information transmission between neurons and are the physical support of memory. It has been realized that synapses are dynamic biological structures. Neurotransmitter receptors diffuse in the neuron membrane and synaptic scaffolding proteins are constantly renewed. We propose a biophysical model that links these different measured quantities for inhibitory synapse components and show how they determine the size of postsynaptic domains. The model predicts that synaptic scaffolds also exist extrasynaptically and that they contribute to fluctuations of synaptic sizes. We confirm by super-resolution microscopy the existence of extrasynaptic scaffolds. Their measured size distribution agrees with the model predictions for specific parameters. The model should be helpful to better understand the dynamics of synapses and their possible levels of regulation.
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Affiliation(s)
- Jonas Ranft
- Laboratoire Physique Statistique, CNRS, Ecole Normale Supérieure, PSL Research University, Université Pierre et Marie Curie, Paris, France
| | - Leandro G. Almeida
- IBENS, Ecole Normale Supérieure, PSL Research University, CNRS, INSERM, Paris, France
| | - Pamela C. Rodriguez
- IBENS, Ecole Normale Supérieure, PSL Research University, CNRS, INSERM, Paris, France
| | - Antoine Triller
- IBENS, Ecole Normale Supérieure, PSL Research University, CNRS, INSERM, Paris, France
- * E-mail: (AT); (VH)
| | - Vincent Hakim
- Laboratoire Physique Statistique, CNRS, Ecole Normale Supérieure, PSL Research University, Université Pierre et Marie Curie, Paris, France
- * E-mail: (AT); (VH)
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21
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Kalimuthu P, Belaidi AA, Schwarz G, Bernhardt PV. Mediated Catalytic Voltammetry of Holo and Heme‐Free Human Sulfite Oxidases. ChemElectroChem 2017. [DOI: 10.1002/celc.201600685] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Palraj Kalimuthu
- School of Chemistry and Molecular Biosciences University of Queensland Brisbane 4072 Australia
| | - Abdel A. Belaidi
- The Florey Institute of Neuroscience and Mental Health University of Melbourne Victoria 3052 Australia
- Institute of Biochemistry Department of Chemistry and Center for Molecular Medicine Cologne University Zülicher Str. 47 50674 Köln Germany
| | - Guenter Schwarz
- Institute of Biochemistry Department of Chemistry and Center for Molecular Medicine Cologne University Zülicher Str. 47 50674 Köln Germany
| | - Paul V. Bernhardt
- School of Chemistry and Molecular Biosciences University of Queensland Brisbane 4072 Australia
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22
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Dejanovic B, Djémié T, Grünewald N, Suls A, Kress V, Hetsch F, Craiu D, Zemel M, Gormley P, Lal D, Myers CT, Mefford HC, Palotie A, Helbig I, Meier JC, De Jonghe P, Weckhuysen S, Schwarz G. Simultaneous impairment of neuronal and metabolic function of mutated gephyrin in a patient with epileptic encephalopathy. EMBO Mol Med 2016; 7:1580-94. [PMID: 26613940 PMCID: PMC4693503 DOI: 10.15252/emmm.201505323] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Synaptic inhibition is essential for shaping the dynamics of neuronal networks, and aberrant inhibition plays an important role in neurological disorders. Gephyrin is a central player at inhibitory postsynapses, directly binds and organizes GABAA and glycine receptors (GABAARs and GlyRs), and is thereby indispensable for normal inhibitory neurotransmission. Additionally, gephyrin catalyzes the synthesis of the molybdenum cofactor (MoCo) in peripheral tissue. We identified a de novo missense mutation (G375D) in the gephyrin gene (GPHN) in a patient with epileptic encephalopathy resembling Dravet syndrome. Although stably expressed and correctly folded, gephyrin‐G375D was non‐synaptically localized in neurons and acted dominant‐negatively on the clustering of wild‐type gephyrin leading to a marked decrease in GABAAR surface expression and GABAergic signaling. We identified a decreased binding affinity between gephyrin‐G375D and the receptors, suggesting that Gly375 is essential for gephyrin–receptor complex formation. Surprisingly, gephyrin‐G375D was also unable to synthesize MoCo and activate MoCo‐dependent enzymes. Thus, we describe a missense mutation that affects both functions of gephyrin and suggest that the identified defect at GABAergic synapses is the mechanism underlying the patient's severe phenotype.
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Affiliation(s)
- Borislav Dejanovic
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany
| | - Tania Djémié
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium
| | - Nora Grünewald
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany
| | - Arvid Suls
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium GENOMED, Center for Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Vanessa Kress
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany
| | - Florian Hetsch
- Division Cell Physiology, Zoological Institute Technische Universität Braunschweig, Braunschweig, Germany
| | - Dana Craiu
- Pediatric Neurology Clinic, Al Obregia Hospital, Bucharest, Romania Department of Neurology, Pediatric Neurology, Psychiatry, Child and Adolescent Psychiatry, and Neurosurgery, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Matthew Zemel
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Padhraig Gormley
- Wellcome Trust Sanger Institute Wellcome Trust Genome Campus, Hinxton, UK Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) University of Cologne, Cologne, Germany Psychiatric & Neurodevelopmental Genetics Unit, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Dennis Lal
- Cologne Center for Genomics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) University of Cologne, Cologne, Germany Department of Neuropediatrics, University Medical Faculty Giessen and Marburg, Giessen, Germany
| | | | - Candace T Myers
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Heather C Mefford
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA, USA
| | - Aarno Palotie
- Wellcome Trust Sanger Institute Wellcome Trust Genome Campus, Hinxton, UK Psychiatric & Neurodevelopmental Genetics Unit, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland Program in Medical and Population Genetics, The Broad Institute of MIT and Harvard, Cambridge, MA, USA The Stanley Center for Psychiatric Research, The Broad Institute of MIT and Harvard, Cambridge, MA, USA Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Ingo Helbig
- Department of Neuropediatrics, University Medical Center Schleswig-Holstein Christian Albrechts University, Kiel, Germany Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jochen C Meier
- Division Cell Physiology, Zoological Institute Technische Universität Braunschweig, Braunschweig, Germany
| | - Peter De Jonghe
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium Division of Neurology, Antwerp University Hospital, Antwerp, Belgium
| | - Sarah Weckhuysen
- Neurogenetics Group, Department of Molecular Genetics, VIB, Antwerp, Belgium Laboratory of Neurogenetics, Institute Born-Bunge University of Antwerp, Antwerp, Belgium Inserm U 1127 CNRS UMR 7225 Sorbonne Universités UPMC Univ Paris 06 UMR S 1127 Institut du Cerveau et de la Moelle épinière, ICM, Paris, France Centre de reference épilepsies rares, Epilepsy unit, AP-HP Groupe hospitalier Pitié-Salpêtrière, F-75013, Paris, France
| | - Guenter Schwarz
- Department of Chemistry, Institute of Biochemistry University of Cologne, Cologne, Germany Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) University of Cologne, Cologne, Germany
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Kasaragod VB, Schindelin H. Structural Framework for Metal Incorporation during Molybdenum Cofactor Biosynthesis. Structure 2016; 24:782-788. [PMID: 27112598 DOI: 10.1016/j.str.2016.02.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 02/15/2016] [Accepted: 02/21/2016] [Indexed: 11/16/2022]
Abstract
The molybdenum cofactor (Moco) is essential for the catalytic activity of all molybdenum-containing enzymes with the exception of nitrogenase. Moco biosynthesis follows an evolutionarily highly conserved pathway and genetic deficiencies in the corresponding human enzymes result in Moco deficiency, which manifests itself in severe neurological symptoms and death in childhood. In humans the final steps of Moco biosynthesis are catalyzed by gephyrin, specifically the penultimate adenylation of molybdopterin (MPT) by its N-terminal G domain (GephG) and the final metal incorporation by its C-terminal E domain (GephE). To better understand the poorly defined molecular framework of this final step, we determined high-resolution crystal structures of GephE in the apo state and in complex with ADP, AMP, and molybdate. Our data provide novel insights into the catalytic steps leading to final Moco maturation, namely deadenylation as well as molybdate binding and insertion.
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Affiliation(s)
- Vikram Babu Kasaragod
- Rudolf Virchow Center for Experimental Biomedicine, Institute of Structural Biology, University of Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany
| | - Hermann Schindelin
- Rudolf Virchow Center for Experimental Biomedicine, Institute of Structural Biology, University of Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany.
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25
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Schwarz G. Molybdenum cofactor and human disease. Curr Opin Chem Biol 2016; 31:179-87. [DOI: 10.1016/j.cbpa.2016.03.016] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/22/2016] [Accepted: 03/22/2016] [Indexed: 11/27/2022]
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Oxygen reactivity of mammalian sulfite oxidase provides a concept for the treatment of sulfite oxidase deficiency. Biochem J 2015; 469:211-21. [PMID: 26171830 DOI: 10.1042/bj20140768] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mammalian sulfite oxidase (SO) is a dimeric enzyme consisting of a molybdenum cofactor- (Moco) and haem-containing domain and catalyses the oxidation of toxic sulfite to sulfate. Following sulfite oxidation, electrons are passed from Moco via the haem cofactor to cytochrome c, the terminal electron acceptor. In contrast, plant SO (PSO) lacks the haem domain and electrons shuttle from Moco to molecular oxygen. Given the high similarity between plant and mammalian SO Moco domains, factors that determine the reactivity of PSO towards oxygen, remained unknown. In the present study, we generated mammalian haem-deficient and truncated SO variants and demonstrated their oxygen reactivity by hydrogen peroxide formation and oxygen-consumption studies. We found that intramolecular electron transfer between Moco and haem showed an inverse correlation to SO oxygen reactivity. Haem-deficient SO variants exhibited oxygen-dependent sulfite oxidation similar to PSO, which was confirmed further using haem-deficient human SO in a cell-based assay. This finding suggests the possibility to use oxygen-reactive SO variants in sulfite detoxification, as the loss of SO activity is causing severe neurodegeneration. Therefore we evaluated the potential use of PEG attachment (PEGylation) as a modification method for future enzyme substitution therapies using oxygen-reactive SO variants, which might use blood-dissolved oxygen as the electron acceptor. PEGylation has been shown to increase the half-life of other therapeutic proteins. PEGylation resulted in the modification of up to eight surface-exposed lysine residues of SO, an increased conformational stability and similar kinetic properties compared with wild-type SO.
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Climer S, Templeton AR, Zhang W. Human gephyrin is encompassed within giant functional noncoding yin-yang sequences. Nat Commun 2015; 6:6534. [PMID: 25813846 PMCID: PMC4380243 DOI: 10.1038/ncomms7534] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 02/06/2015] [Indexed: 12/31/2022] Open
Abstract
Gephyrin is a highly-conserved gene that is vital for the organization of proteins at inhibitory receptors, molybdenum cofactor biosynthesis, and other diverse functions. Its specific function is intricately regulated and its aberrant activities have been observed for a number of human diseases. Here we report a remarkable yin-yang haplotype pattern encompassing gephyrin. Yin-yang haplotypes arise when a stretch of DNA evolves to present two disparate forms that bear differing states for nucleotide variations along their lengths. The gephyrin yin-yang pair consists of 284 divergent nucleotide states and both variants vary drastically from their mutual ancestral haplotype, suggesting rapid evolution. Several independent lines of evidence indicate strong positive selection on the region and suggest these high-frequency haplotypes represent two distinct functional mechanisms. This discovery holds potential to deepen our understanding of variable human-specific regulation of gephyrin while providing clues for rapid evolutionary events and allelic migrations buried within human history.
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Affiliation(s)
- Sharlee Climer
- Department of Computer Science and Engineering, Washington University, St Louis, Missouri 63130, USA
| | - Alan R Templeton
- 1] Department of Biology, Washington University, St Louis, Missouri 63130, USA [2] Department of Genetics, Washington University, St Louis, Missouri 63110, USA [3] Department of Evolutionary and Environmental Biology, University of Haifa, Haifa 31905, Israel
| | - Weixiong Zhang
- 1] Department of Computer Science and Engineering, Washington University, St Louis, Missouri 63130, USA [2] Department of Genetics, Washington University, St Louis, Missouri 63110, USA [3] Institute for Systems Biology, Jianghan University, Wuhan, Hubei 430056, China
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Abstract
The transition element molybdenum (Mo) is of primordial importance for biological systems, because it is required by enzymes catalyzing key reactions in the global carbon, sulfur, and nitrogen metabolism. To gain biological activity, Mo has to be complexed by a special cofactor. With the exception of bacterial nitrogenase, all Mo-dependent enzymes contain a unique pyranopterin-based cofactor coordinating a Mo atom at their catalytic site. Various types of reactions are catalyzed by Mo-enzymes in prokaryotes including oxygen atom transfer, sulfur or proton transfer, hydroxylation, or even nonredox reactions. Mo-enzymes are widespread in prokaryotes and many of them were likely present in the Last Universal Common Ancestor. To date, more than 50--mostly bacterial--Mo-enzymes are described in nature. In a few eubacteria and in many archaea, Mo is replaced by tungsten bound to the same unique pyranopterin. How Mo-cofactor is synthesized in bacteria is reviewed as well as the way until its insertion into apo-Mo-enzymes.
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Bouvier ES, Koza SM. Advances in size-exclusion separations of proteins and polymers by UHPLC. Trends Analyt Chem 2014. [DOI: 10.1016/j.trac.2014.08.002] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Tejada-Jiménez M, Schwarz G. Molybdenum and Tungsten. BINDING, TRANSPORT AND STORAGE OF METAL IONS IN BIOLOGICAL CELLS 2014. [DOI: 10.1039/9781849739979-00223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Molybdenum (Mo) is an essential micronutrient for the majority of organisms ranging from bacteria to animals. To fulfil its biological role, it is incorporated into a pterin-based Mo-cofactor (Moco) and can be found in the active centre of more than 50 enzymes that are involved in key reactions of carbon, nitrogen and sulfur metabolism. Five of the Mo-enzymes are present in eukaryotes: nitrate reductase (NR), sulfite oxidase (SO), aldehyde oxidase (AO), xanthine oxidase (XO) and the amidoxime-reducing component (mARC). Cells acquire Mo in form of the oxyanion molybdate using specific molybdate transporters. In bacteria, molybdate transport is an extensively studied process and is mediated mainly by the ATP-binding cassette system ModABC. In contrast, in eukaryotes, molybdate transport is poorly understood since specific molybdate transporters remained unknown until recently. Two rather distantly related families of proteins, MOT1 and MOT2, are involved in eukaryotic molybdate transport. They each feature high-affinity molybdate transporters that regulate the intracellular concentration of Mo and thus control activity of Mo-enzymes. The present chapter presents an overview of the biological functions of Mo with special focus on recent data related to its uptake, binding and storage.
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Affiliation(s)
- Manuel Tejada-Jiménez
- Institute of Biochemistry, Department of Chemistry, University of Cologne Zuelpicher Str. 47 Cologne 50674 Germany
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, University of Cologne Zuelpicher Str. 47 Cologne 50674 Germany
- Center for Molecular Medicine Cologne, University of Cologne Robert-Koch Str. 21 Cologne 50931 Germany
- Cluster of Excellence in Ageing Research, CECAD Research Center Joseph-Stelzmann-Str. 26 Cologne 50931 Germany
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Mendel RR, Leimkühler S. The biosynthesis of the molybdenum cofactors. J Biol Inorg Chem 2014; 20:337-47. [PMID: 24980677 DOI: 10.1007/s00775-014-1173-y] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 06/09/2014] [Indexed: 12/11/2022]
Abstract
The biosynthesis of the molybdenum cofactors (Moco) is an ancient, ubiquitous, and highly conserved pathway leading to the biochemical activation of molybdenum. Moco is the essential component of a group of redox enzymes, which are diverse in terms of their phylogenetic distribution and their architectures, both at the overall level and in their catalytic geometry. A wide variety of transformations are catalyzed by these enzymes at carbon, sulfur and nitrogen atoms, which include the transfer of an oxo group or two electrons to or from the substrate. More than 50 molybdoenzymes were identified to date. In all molybdoenzymes except nitrogenase, molybdenum is coordinated to a dithiolene group on the 6-alkyl side chain of a pterin called molybdopterin (MPT). The biosynthesis of Moco can be divided into three general steps, with a fourth one present only in bacteria and archaea: (1) formation of the cyclic pyranopterin monophosphate, (2) formation of MPT, (3) insertion of molybdenum into molybdopterin to form Moco, and (4) additional modification of Moco in bacteria with the attachment of a nucleotide to the phosphate group of MPT, forming the dinucleotide variant of Moco. This review will focus on the biosynthesis of Moco in bacteria, humans and plants.
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Affiliation(s)
- Ralf R Mendel
- Institute of Plant Biology, Braunschweig University of Technology, Humboldtstr. 1, 38106, Braunschweig, Germany,
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32
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Dejanovic B, Lal D, Catarino CB, Arjune S, Belaidi AA, Trucks H, Vollmar C, Surges R, Kunz WS, Motameny S, Altmüller J, Köhler A, Neubauer BA, EPICURE Consortium, Nürnberg P, Noachtar S, Schwarz G, Sander T. Exonic microdeletions of the gephyrin gene impair GABAergic synaptic inhibition in patients with idiopathic generalized epilepsy. Neurobiol Dis 2014; 67:88-96. [DOI: 10.1016/j.nbd.2014.02.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 01/09/2014] [Accepted: 02/10/2014] [Indexed: 12/29/2022] Open
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Abstract
Molybdenum is an essential trace element and crucial for the survival of animals. Four mammalian Mo-dependent enzymes are known, all of them harboring a pterin-based molybdenum cofactor (Moco) in their active site. In these enzymes, molybdenum catalyzes oxygen transfer reactions from or to substrates using water as oxygen donor or acceptor. Molybdenum shuttles between two oxidation states, Mo(IV) and Mo(VI). Following substrate reduction or oxidation, electrons are subsequently shuttled by either inter- or intra-molecular electron transfer chains involving prosthetic groups such as heme or iron-sulfur clusters. In all organisms studied so far, Moco is synthesized by a highly conserved multi-step biosynthetic pathway. A deficiency in the biosynthesis of Moco results in a pleitropic loss of all four human Mo-enzyme activities and in most cases in early childhood death. In this review we first introduce general aspects of molybdenum biochemistry before we focus on the functions and deficiencies of two Mo-enzymes, xanthine dehydrogenase and sulfite oxidase, caused either by deficiency of the apo-protein or a pleiotropic loss of Moco due to a genetic defect in its biosynthesis. The underlying molecular basis of Moco deficiency, possible treatment options and links to other diseases, such as neuropsychiatric disorders, will be discussed.
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Affiliation(s)
- Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, Center for Molecular Medicine, University of Cologne, Zülpicher Strasse 47, D-50674, Köln, Germany,
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Abstract
The neurotransmitters GABA and glycine mediate fast synaptic inhibition by activating ligand-gated chloride channels--namely, type A GABA (GABA(A)) and glycine receptors. Both types of receptors are anchored postsynaptically by gephyrin, which self-assembles into a scaffold and interacts with the cytoskeleton. Current research indicates that postsynaptic gephyrin clusters are dynamic assemblies that are held together and regulated by multiple protein-protein interactions. Moreover, post-translational modifications of gephyrin regulate the formation and plasticity of GABAergic synapses by altering the clustering properties of postsynaptic scaffolds and thereby the availability and function of receptors and other signalling molecules. Here, we discuss the formation and regulation of the gephyrin scaffold, its role in GABAergic and glycinergic synaptic function and the implications for the pathophysiology of brain disorders caused by abnormal inhibitory neurotransmission.
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Affiliation(s)
- Russ Hille
- Department of Biochemistry, University of California, Riverside, Riverside, California 92521, United States
| | - James Hall
- Department of Biochemistry, University of California, Riverside, Riverside, California 92521, United States
| | - Partha Basu
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, Pennsylvania 15282, United States
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36
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Fritschy JM, Panzanelli P. GABAAreceptors and plasticity of inhibitory neurotransmission in the central nervous system. Eur J Neurosci 2014; 39:1845-65. [DOI: 10.1111/ejn.12534] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 01/29/2014] [Accepted: 01/29/2014] [Indexed: 12/11/2022]
Affiliation(s)
- Jean-Marc Fritschy
- Institute of Pharmacology and Toxicology; University of Zurich; Winterthurerstrasse 190 8057 Zurich Switzerland
- Neuroscience Center Zurich; University of Zurich and ETH; Zurich Switzerland
| | - Patrizia Panzanelli
- Department of Neuroscience Rita Levi Montalcini; University of Turin; Turin Italy
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Klein EL, Belaidi AA, Raitsimring AM, Davis AC, Krämer T, Astashkin AV, Neese F, Schwarz G, Enemark JH. Pulsed electron paramagnetic resonance spectroscopy of (33)S-labeled molybdenum cofactor in catalytically active bioengineered sulfite oxidase. Inorg Chem 2014; 53:961-71. [PMID: 24387640 PMCID: PMC3927148 DOI: 10.1021/ic4023954] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Molybdenum enzymes contain at least one pyranopterin dithiolate (molybdopterin, MPT) moiety that coordinates Mo through two dithiolate (dithiolene) sulfur atoms. For sulfite oxidase (SO), hyperfine interactions (hfi) and nuclear quadrupole interactions (nqi) of magnetic nuclei (I ≠ 0) near the Mo(V) (d(1)) center have been measured using high-resolution pulsed electron paramagnetic resonance (EPR) methods and interpreted with the help of density functional theory (DFT) calculations. These have provided important insights about the active site structure and the reaction mechanism of the enzyme. However, it has not been possible to use EPR to probe the dithiolene sulfurs directly since naturally abundant (32)S has no nuclear spin (I = 0). Here we describe direct incorporation of (33)S (I = 3/2), the only stable magnetic sulfur isotope, into MPT using controlled in vitro synthesis with purified proteins. The electron spin echo envelope modulation (ESEEM) spectra from (33)S-labeled MPT in this catalytically active SO variant are dominated by the "interdoublet" transition arising from the strong nuclear quadrupole interaction, as also occurs for the (33)S-labeled exchangeable equatorial sulfite ligand [ Klein, E. L., et al. Inorg. Chem. 2012 , 51 , 1408 - 1418 ]. The estimated experimental hfi and nqi parameters for (33)S (aiso = 3 MHz and e(2)Qq/h = 25 MHz) are in good agreement with those predicted by DFT. In addition, the DFT calculations show that the two (33)S atoms are indistinguishable by EPR and reveal a strong intermixing between their out-of-plane pz orbitals and the dxy orbital of Mo(V).
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Affiliation(s)
- Eric L. Klein
- Department of Chemistry and Biochemistry, The University of Arizona, 1306 E. University Blvd., Tucson, AZ 85721-0041, USA
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Abdel Ali Belaidi
- Institute of Biochemistry, University of Cologne, Zülpicher Str. 47, 50674 Cologne, Germany
| | - Arnold M. Raitsimring
- Department of Chemistry and Biochemistry, The University of Arizona, 1306 E. University Blvd., Tucson, AZ 85721-0041, USA
| | - Amanda C. Davis
- Department of Chemistry and Biochemistry, The University of Arizona, 1306 E. University Blvd., Tucson, AZ 85721-0041, USA
| | - Tobias Krämer
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Andrei V. Astashkin
- Department of Chemistry and Biochemistry, The University of Arizona, 1306 E. University Blvd., Tucson, AZ 85721-0041, USA
| | - Frank Neese
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Günter Schwarz
- Institute of Biochemistry, University of Cologne, Zülpicher Str. 47, 50674 Cologne, Germany
| | - John H. Enemark
- Department of Chemistry and Biochemistry, The University of Arizona, 1306 E. University Blvd., Tucson, AZ 85721-0041, USA
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Havarushka N, Fischer-Schrader K, Lamkemeyer T, Schwarz G. Structural basis of thermal stability of the tungsten cofactor synthesis protein MoaB from Pyrococcus furiosus. PLoS One 2014; 9:e86030. [PMID: 24465852 PMCID: PMC3896444 DOI: 10.1371/journal.pone.0086030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 12/06/2013] [Indexed: 12/17/2022] Open
Abstract
Molybdenum and tungsten cofactors share a similar pterin-based scaffold, which hosts an ene-dithiolate function being essential for the coordination of either molybdenum or tungsten. The biosynthesis of both cofactors involves a multistep pathway, which ends with the activation of the metal binding pterin (MPT) by adenylylation before the respective metal is incorporated. In the hyperthermophilic organism Pyrococcus furiosus, the hexameric protein MoaB (PfuMoaB) has been shown to catalyse MPT-adenylylation. Here we determined the crystal structure of PfuMoaB at 2.5 Å resolution and identified key residues of α3-helix mediating hexamer formation. Given that PfuMoaB homologues from mesophilic organisms form trimers, we investigated the impact on PfuMoaB hexamerization on thermal stability and activity. Using structure-guided mutagenesis, we successfully disrupted the hexamer interface in PfuMoaB. The resulting PfuMoaB-H3 variant formed monomers, dimers and trimers as determined by size exclusion chromatography. Circular dichroism spectroscopy as well as chemical cross-linking coupled to mass spectrometry confirmed a wild-type-like fold of the protomers as well as inter-subunits contacts. The melting temperature of PfuMoaB-H3 was found to be reduced by more than 15°C as determined by differential scanning calorimetry, thus demonstrating hexamerization as key determinant for PfuMoaB thermal stability. Remarkably, while a loss of activity at temperatures higher than 50°C was observed in the PfuMoaB-H3 variant, at lower temperatures, we determined a significantly increased catalytic activity. The latter suggests a gain in conformational flexibility caused by the disruption of the hexamerization interface.
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Affiliation(s)
- Nastassia Havarushka
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Cologne, Germany
| | | | - Tobias Lamkemeyer
- Cluster of Excellence in Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Guenter Schwarz
- Institute of Biochemistry, Department of Chemistry, University of Cologne, Cologne, Germany
- Cluster of Excellence in Cellular Stress Responses in Aging-associated Diseases (CECAD), University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
- * E-mail:
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39
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Pushie MJ, Cotelesage JJ, George GN. Molybdenum and tungsten oxygen transferases – structural and functional diversity within a common active site motif. Metallomics 2014; 6:15-24. [DOI: 10.1039/c3mt00177f] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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40
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Sander B, Tria G, Shkumatov AV, Kim EY, Grossmann JG, Tessmer I, Svergun DI, Schindelin H. Structural characterization of gephyrin by AFM and SAXS reveals a mixture of compact and extended states. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:2050-60. [DOI: 10.1107/s0907444913018714] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 07/05/2013] [Indexed: 11/10/2022]
Abstract
Gephyrin is a trimeric protein involved in the final steps of molybdenum-cofactor (Moco) biosynthesis and in the clustering of inhibitory glycine and GABAAreceptors at postsynaptic specializations. Each protomer consists of stably folded domains (referred to as the G and E domains) located at either terminus and connected by a proteolytically sensitive linker of ∼150 residues. Both terminal domains can oligomerize in their isolated forms; however, in the context of the full-length protein only the G-domain trimer is permanently present, whereas E-domain dimerization is prevented. Atomic force microscopy (AFM) and small-angle X-ray scattering (SAXS) reveal a high degree of flexibility in the structure of gephyrin. The results imply an equilibrium between compact and extended conformational states in solution, with a preference for compact states. CD spectroscopy suggests that a partial compaction is achieved by interactions of the linker with the G and E domains. Taken together, the data provide a rationale for the role of the linker in the overall structure and the conformational dynamics of gephyrin.
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41
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Abstract
The transition element molybdenum needs to be complexed by a special cofactor to gain catalytic activity. Molybdenum is bound to a unique pterin, thus forming the molybdenum cofactor (Moco), which, in different variants, is the active compound at the catalytic site of all molybdenum-containing enzymes in nature, except bacterial molybdenum nitrogenase. The biosynthesis of Moco involves the complex interaction of six proteins and is a process of four steps, which also require iron, ATP, and copper. After its synthesis, Moco is distributed, involving Moco-binding proteins. A deficiency in the biosynthesis of Moco has lethal consequences for the respective organisms.
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Affiliation(s)
- Ralf R Mendel
- Department of Plant Biology, Braunschweig University of Technology, 38106 Braunschweig, Germany.
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42
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Clinch K, Watt DK, Dixon RA, Baars SM, Gainsford GJ, Tiwari A, Schwarz G, Saotome Y, Storek M, Belaidi AA, Santamaria-Araujo JA. Synthesis of Cyclic Pyranopterin Monophosphate, a Biosynthetic Intermediate in the Molybdenum Cofactor Pathway. J Med Chem 2013; 56:1730-8. [DOI: 10.1021/jm301855r] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | | | | | - Ashish Tiwari
- Alexion Pharmaceuticals Inc., 352 Knotter Drive, Cheshire, Connecticut 06410,
United States
| | - Günter Schwarz
- Colbourne Pharmaceuticals GmbH, Viktoriaweg 7, 53859 Niederkassel, Germany
- Institute of Biochemistry, Department
of Chemistry and Center for Molecular Medicine Cologne, University of Cologne, Zuelpicher Strasse 47, 50674
Cologne, Germany
| | - Yas Saotome
- Alexion Pharmaceuticals Inc., 352 Knotter Drive, Cheshire, Connecticut 06410,
United States
| | - Michael Storek
- Alexion Pharmaceuticals Inc., 352 Knotter Drive, Cheshire, Connecticut 06410,
United States
| | - Abdel A. Belaidi
- Colbourne Pharmaceuticals GmbH, Viktoriaweg 7, 53859 Niederkassel, Germany
- Institute of Biochemistry, Department
of Chemistry and Center for Molecular Medicine Cologne, University of Cologne, Zuelpicher Strasse 47, 50674
Cologne, Germany
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Tejada-Jiménez M, Chamizo-Ampudia A, Galván A, Fernández E, Llamas Á. Molybdenum metabolism in plants. Metallomics 2013; 5:1191-203. [DOI: 10.1039/c3mt00078h] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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