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Francesconi V, Rizzo M, Pozzi C, Tagliazucchi L, Konchie Simo CU, Saporito G, Landi G, Mangani S, Carbone A, Schenone S, Santarém N, Tavares J, Cordeiro-da-Silva A, Costi MP, Tonelli M. Identification of Innovative Folate Inhibitors Leveraging the Amino Dihydrotriazine Motif from Cycloguanil for Their Potential as Anti- Trypanosoma brucei Agents. ACS Infect Dis 2024; 10:2755-2774. [PMID: 38953453 DOI: 10.1021/acsinfecdis.4c00113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
Folate enzymes, namely, dihydrofolate reductase (DHFR) and pteridine reductase (PTR1) are acknowledged targets for the development of antiparasitic agents against Trypanosomiasis and Leishmaniasis. Based on the amino dihydrotriazine motif of the drug Cycloguanil (Cyc), a known inhibitor of both folate enzymes, we have identified two novel series of inhibitors, the 2-amino triazino benzimidazoles (1) and 2-guanidino benzimidazoles (2), as their open ring analogues. Enzymatic screening was carried out against PTR1, DHFR, and thymidylate synthase (TS). The crystal structures of TbDHFR and TbPTR1 in complex with selected compounds experienced in both cases a substrate-like binding mode and allowed the rationalization of the main chemical features supporting the inhibitor ability to target folate enzymes. Biological evaluation of both series was performed against T. brucei and L. infantum and the toxicity against THP-1 human macrophages. Notably, the 5,6-dimethyl-2-guanidinobenzimidazole 2g resulted to be the most potent (Ki = 9 nM) and highly selective TbDHFR inhibitor, 6000-fold over TbPTR1 and 394-fold over hDHFR. The 5,6-dimethyl tricyclic analogue 1g, despite showing a lower potency and selectivity profile than 2g, shared a comparable antiparasitic activity against T. brucei in the low micromolar domain. The dichloro-substituted 2-guanidino benzimidazoles 2c and 2d revealed their potent and broad-spectrum antitrypanosomatid activity affecting the growth of T. brucei and L. infantum parasites. Therefore, both chemotypes could represent promising templates that could be valorized for further drug development.
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Affiliation(s)
- Valeria Francesconi
- Department of Pharmacy, University of Genoa, viale Benedetto XV n.3, Genoa 16132, Italy
| | - Marco Rizzo
- Department of Pharmacy, University of Genoa, viale Benedetto XV n.3, Genoa 16132, Italy
| | - Cecilia Pozzi
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via Aldo Moro 2, Siena 53100, Italy
- Consorzio Interuniversitario Risonanze Magnetiche di Metallo Proteine (CIMMP), Via Luigi Sacconi 6, Sesto Fiorentino (FI) 50019, Italy
| | - Lorenzo Tagliazucchi
- Department of Life Science, University of Modena and Reggio Emilia, via Campi 103, Modena 41125, Italy
- Doctorate School in Clinical and Experimental Medicine (CEM), University of Modena and Reggio Emilia, Via Campi 287, Modena 41125, Italy
| | - Claude U Konchie Simo
- Department of Life Science, University of Modena and Reggio Emilia, via Campi 103, Modena 41125, Italy
| | - Giulia Saporito
- Department of Life Science, University of Modena and Reggio Emilia, via Campi 103, Modena 41125, Italy
| | - Giacomo Landi
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via Aldo Moro 2, Siena 53100, Italy
| | - Stefano Mangani
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, via Aldo Moro 2, Siena 53100, Italy
| | - Anna Carbone
- Department of Pharmacy, University of Genoa, viale Benedetto XV n.3, Genoa 16132, Italy
| | - Silvia Schenone
- Department of Pharmacy, University of Genoa, viale Benedetto XV n.3, Genoa 16132, Italy
| | - Nuno Santarém
- i3S - Institute for Research and Innovation in Health, University of Porto, Rua Alfredo Allen, 208, Porto 4200-135, Portugal
| | - Joana Tavares
- i3S - Institute for Research and Innovation in Health, University of Porto, Rua Alfredo Allen, 208, Porto 4200-135, Portugal
| | - Anabela Cordeiro-da-Silva
- i3S - Institute for Research and Innovation in Health, University of Porto, Rua Alfredo Allen, 208, Porto 4200-135, Portugal
- Department of Life Science, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira, 228, Porto 4050-313, Portugal
| | - Maria Paola Costi
- Department of Life Science, University of Modena and Reggio Emilia, via Campi 103, Modena 41125, Italy
| | - Michele Tonelli
- Department of Pharmacy, University of Genoa, viale Benedetto XV n.3, Genoa 16132, Italy
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Cardozo G, Mastrogiovanni M, Zeida A, Viera N, Radi R, Reyes AM, Trujillo M. Mitochondrial Peroxiredoxin 3 Is Rapidly Oxidized and Hyperoxidized by Fatty Acid Hydroperoxides. Antioxidants (Basel) 2023; 12:antiox12020408. [PMID: 36829967 PMCID: PMC9952270 DOI: 10.3390/antiox12020408] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/19/2023] [Accepted: 01/28/2023] [Indexed: 02/11/2023] Open
Abstract
Human peroxiredoxin 3 (HsPrx3) is a thiol-based peroxidase responsible for the reduction of most hydrogen peroxide and peroxynitrite formed in mitochondria. Mitochondrial disfunction can lead to membrane lipoperoxidation, resulting in the formation of lipid-bound fatty acid hydroperoxides (LFA-OOHs) which can be released to become free fatty acid hydroperoxides (fFA-OOHs). Herein, we report that HsPrx3 is oxidized and hyperoxidized by fFA-OOHs including those derived from arachidonic acid and eicosapentaenoic acid peroxidation at position 15 with remarkably high rate constants of oxidation (>3.5 × 107 M-1s-1) and hyperoxidation (~2 × 107 M-1s-1). The endoperoxide-hydroperoxide PGG2, an intermediate in prostanoid synthesis, oxidized HsPrx3 with a similar rate constant, but was less effective in causing hyperoxidation. Biophysical methodologies suggest that HsPrx3 can bind hydrophobic structures. Indeed, molecular dynamic simulations allowed the identification of a hydrophobic patch near the enzyme active site that can allocate the hydroperoxide group of fFA-OOHs in close proximity to the thiolate in the peroxidatic cysteine. Simulations performed using available and herein reported kinetic data indicate that HsPrx3 should be considered a main target for mitochondrial fFA-OOHs. Finally, kinetic simulation analysis support that mitochondrial fFA-OOHs formation fluxes in the range of nM/s are expected to contribute to HsPrx3 hyperoxidation, a modification that has been detected in vivo under physiological and pathological conditions.
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Affiliation(s)
- Giuliana Cardozo
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Mauricio Mastrogiovanni
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Ari Zeida
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Nicolás Viera
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Rafael Radi
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
| | - Aníbal M. Reyes
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
- Correspondence: (A.M.R.); (M.T.)
| | - Madia Trujillo
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Centro de Investigaciones Biomédicas, Universidad de la República, Montevideo 11800, Uruguay
- Correspondence: (A.M.R.); (M.T.)
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Ali V, Behera S, Nawaz A, Equbal A, Pandey K. Unique thiol metabolism in trypanosomatids: Redox homeostasis and drug resistance. ADVANCES IN PARASITOLOGY 2022; 117:75-155. [PMID: 35878950 DOI: 10.1016/bs.apar.2022.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Trypanosomatids are mainly responsible for heterogeneous parasitic diseases: Leishmaniasis, Sleeping sickness, and Chagas disease and control of these diseases implicates serious challenges due to the emergence of drug resistance. Redox-active biomolecules are the endogenous substances in organisms, which play important role in the regulation of redox homeostasis. The redox-active substances like glutathione, trypanothione, cysteine, cysteine persulfides, etc., and other inorganic intermediates (hydrogen peroxide, nitric oxide) are very useful as defence mechanism. In the present review, the suitability of trypanothione and other essential thiol molecules of trypanosomatids as drug targets are described in Leishmania and Trypanosoma. We have explored the role of tryparedoxin, tryparedoxin peroxidase, ascorbate peroxidase, superoxide dismutase, and glutaredoxins in the anti-oxidant mechanism and drug resistance. Up-regulation of some proteins in trypanothione metabolism helps the parasites in survival against drug pressure (sodium stibogluconate, Amphotericin B, etc.) and oxidative stress. These molecules accept electrons from the reduced trypanothione and donate their electrons to other proteins, and these proteins reduce toxic molecules, neutralize reactive oxygen, or nitrogen species; and help parasites to cope with oxidative stress. Thus, a better understanding of the role of these molecules in drug resistance and redox homeostasis will help to target metabolic pathway proteins to combat Leishmaniasis and trypanosomiases.
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Affiliation(s)
- Vahab Ali
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India.
| | - Sachidananda Behera
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India
| | - Afreen Nawaz
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India
| | - Asif Equbal
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India; Department of Botany, Araria College, Purnea University, Purnia, Bihar, India
| | - Krishna Pandey
- Department of Clinical Medicine, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India
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Docampo R, Vercesi AE. Mitochondrial Ca 2+ and Reactive Oxygen Species in Trypanosomatids. Antioxid Redox Signal 2022; 36:969-983. [PMID: 34218689 PMCID: PMC9125514 DOI: 10.1089/ars.2021.0058] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/31/2021] [Accepted: 06/22/2021] [Indexed: 02/06/2023]
Abstract
Significance: Millions of people are infected with trypanosomatids and new therapeutic approaches are needed. Trypanosomatids possess one mitochondrion per cell and its study has led to discoveries of general biological interest. These mitochondria, as in their animal counterparts, generate reactive oxygen species (ROS) and have evolved enzymatic and nonenzymatic defenses against them. Mitochondrial calcium ion (Ca2+) overload leads to generation of ROS and its study could lead to relevant information on the biology of trypanosomatids and to novel drug targets. Recent Advances: Mitochondrial Ca2+ is normally involved in maintaining the bioenergetics of trypanosomes, but when Ca2+ overload occurs, it is associated with cell death. Trypanosomes lack key players in the mechanism of cell death described in mammalian cells, although mitochondrial Ca2+ overload results in collapse of their membrane potential, production of ROS, and cytochrome c release. They are also very resistant to mitochondrial permeability transition, and cell death after mitochondrial Ca2+ overload depends on generation of ROS. Critical Issues: In this review, we consider the mechanisms of mitochondrial oxidant generation and removal and the involvement of Ca2+ in trypanosome cell death. Future Directions: More studies are required to determine the reactions involved in generation of ROS by the mitochondria of trypanosomatids, their enzymatic and nonenzymatic defenses against ROS, and the occurrence and composition of a mitochondrial permeability transition pore. Antioxid. Redox Signal. 36, 969-983.
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Affiliation(s)
- Roberto Docampo
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
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5
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Piñeyro MD, Arias D, Parodi-Talice A, Guerrero S, Robello C. Trypanothione Metabolism as Drug Target for Trypanosomatids. Curr Pharm Des 2021; 27:1834-1846. [PMID: 33308115 DOI: 10.2174/1381612826666201211115329] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 10/01/2020] [Accepted: 10/08/2020] [Indexed: 11/22/2022]
Abstract
Chagas Disease, African sleeping sickness, and leishmaniasis are neglected diseases caused by pathogenic trypanosomatid parasites, which have a considerable impact on morbidity and mortality in poor countries. The available drugs used as treatment have high toxicity, limited access, and can cause parasite drug resistance. Long-term treatments, added to their high toxicity, result in patients that give up therapy. Trypanosomatids presents a unique trypanothione based redox system, which is responsible for maintaining the redox balance. Therefore, inhibition of these essential and exclusive parasite's metabolic pathways, absent from the mammalian host, could lead to the development of more efficient and safe drugs. The system contains different redox cascades, where trypanothione and tryparedoxins play together a central role in transferring reduced power to different enzymes, such as 2-Cys peroxiredoxins, non-selenium glutathione peroxidases, ascorbate peroxidases, glutaredoxins and methionine sulfoxide reductases, through NADPH as a source of electrons. There is sufficient evidence that this complex system is essential for parasite survival and infection. In this review, we explore what is known in terms of essentiality, kinetic and structural data, and the development of inhibitors of enzymes from this trypanothione-based redox system. The recent advances and limitations in the development of lead inhibitory compounds targeting these enzymes have been discussed. The combination of molecular biology, bioinformatics, genomics, and structural biology is fundamental since the knowledge of unique features of the trypanothione-dependent system will provide tools for rational drug design in order to develop better treatments for these diseases.
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Affiliation(s)
| | - Diego Arias
- Instituto de Agrobiotecnologia del Litoral y Facultad de Bioquimica y Ciencias Biologicas, CONICET-UNL, Santa F, Argentina
| | | | - Sergio Guerrero
- Instituto de Agrobiotecnologia del Litoral y Facultad de Bioquimica y Ciencias Biologicas, CONICET-UNL, Santa F, Argentina
| | - Carlos Robello
- Unidad de Biologia Molecular, Instituto Pasteur Montevideo, Montevideo, Uruguay
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6
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Meyer AJ, Dreyer A, Ugalde JM, Feitosa-Araujo E, Dietz KJ, Schwarzländer M. Shifting paradigms and novel players in Cys-based redox regulation and ROS signaling in plants - and where to go next. Biol Chem 2020; 402:399-423. [PMID: 33544501 DOI: 10.1515/hsz-2020-0291] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/09/2020] [Indexed: 02/06/2023]
Abstract
Cys-based redox regulation was long regarded a major adjustment mechanism of photosynthesis and metabolism in plants, but in the recent years, its scope has broadened to most fundamental processes of plant life. Drivers of the recent surge in new insights into plant redox regulation have been the availability of the genome-scale information combined with technological advances such as quantitative redox proteomics and in vivo biosensing. Several unexpected findings have started to shift paradigms of redox regulation. Here, we elaborate on a selection of recent advancements, and pinpoint emerging areas and questions of redox biology in plants. We highlight the significance of (1) proactive H2O2 generation, (2) the chloroplast as a unique redox site, (3) specificity in thioredoxin complexity, (4) how to oxidize redox switches, (5) governance principles of the redox network, (6) glutathione peroxidase-like proteins, (7) ferroptosis, (8) oxidative protein folding in the ER for phytohormonal regulation, (9) the apoplast as an unchartered redox frontier, (10) redox regulation of respiration, (11) redox transitions in seed germination and (12) the mitochondria as potential new players in reductive stress safeguarding. Our emerging understanding in plants may serve as a blueprint to scrutinize principles of reactive oxygen and Cys-based redox regulation across organisms.
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Affiliation(s)
- Andreas J Meyer
- Chemical Signalling, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, D-53113Bonn, Germany
| | - Anna Dreyer
- Biochemistry and Physiology of Plants, Faculty of Biology, W5-134, Bielefeld University, University Street 25, D-33501Bielefeld, Germany
| | - José M Ugalde
- Chemical Signalling, Institute of Crop Science and Resource Conservation (INRES), University of Bonn, Friedrich-Ebert-Allee 144, D-53113Bonn, Germany
| | - Elias Feitosa-Araujo
- Plant Energy Biology, Institute of Plant Biology and Biotechnology (IBBP), University of Münster, Schlossplatz 8, D-48143Münster, Germany
| | - Karl-Josef Dietz
- Biochemistry and Physiology of Plants, Faculty of Biology, W5-134, Bielefeld University, University Street 25, D-33501Bielefeld, Germany
| | - Markus Schwarzländer
- Plant Energy Biology, Institute of Plant Biology and Biotechnology (IBBP), University of Münster, Schlossplatz 8, D-48143Münster, Germany
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7
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Kostyuk AI, Panova AS, Kokova AD, Kotova DA, Maltsev DI, Podgorny OV, Belousov VV, Bilan DS. In Vivo Imaging with Genetically Encoded Redox Biosensors. Int J Mol Sci 2020; 21:E8164. [PMID: 33142884 PMCID: PMC7662651 DOI: 10.3390/ijms21218164] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 12/13/2022] Open
Abstract
Redox reactions are of high fundamental and practical interest since they are involved in both normal physiology and the pathogenesis of various diseases. However, this area of research has always been a relatively problematic field in the context of analytical approaches, mostly because of the unstable nature of the compounds that are measured. Genetically encoded sensors allow for the registration of highly reactive molecules in real-time mode and, therefore, they began a new era in redox biology. Their strongest points manifest most brightly in in vivo experiments and pave the way for the non-invasive investigation of biochemical pathways that proceed in organisms from different systematic groups. In the first part of the review, we briefly describe the redox sensors that were used in vivo as well as summarize the model systems to which they were applied. Next, we thoroughly discuss the biological results obtained in these studies in regard to animals, plants, as well as unicellular eukaryotes and prokaryotes. We hope that this work reflects the amazing power of this technology and can serve as a useful guide for biologists and chemists who work in the field of redox processes.
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Affiliation(s)
- Alexander I. Kostyuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Anastasiya S. Panova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Aleksandra D. Kokova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Daria A. Kotova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Dmitry I. Maltsev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Federal Center for Cerebrovascular Pathology and Stroke, 117997 Moscow, Russia
| | - Oleg V. Podgorny
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Vsevolod V. Belousov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Federal Center for Cerebrovascular Pathology and Stroke, 117997 Moscow, Russia
- Institute for Cardiovascular Physiology, Georg August University Göttingen, D-37073 Göttingen, Germany
| | - Dmitry S. Bilan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
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Bogacz M, Dirdjaja N, Wimmer B, Habich C, Krauth-Siegel RL. The mitochondrial peroxiredoxin displays distinct roles in different developmental stages of African trypanosomes. Redox Biol 2020; 34:101547. [PMID: 32388269 PMCID: PMC7218024 DOI: 10.1016/j.redox.2020.101547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/11/2020] [Accepted: 04/20/2020] [Indexed: 12/26/2022] Open
Abstract
Hydroperoxide reduction in African trypanosomes relies on 2-Cys-peroxiredoxins (Prxs) and glutathione peroxidase-type enzymes (Pxs) which both obtain their reducing equivalents from the trypanothione/tryparedoxin couple and thus act as tryparedoxin peroxidases. While the cytosolic forms of the peroxidases are essential, the mitochondrial mPrx and Px III appear dispensable in bloodstream Trypanosoma brucei. This led to the suggestion that in this developmental stage which is characterized by a mitochondrion that lacks an active respiratory chain, only one of the two peroxidases might be required. Here we show that bloodstream cells in which the Px III gene is deleted and mPrx is down-regulated by RNA interference, proliferate as the parental cells indicating that both mitochondrial peroxidases are dispensable. However, when we raised the culture temperature to 39 °C, mPrx-depleted cells died indicating that under conditions mimicking a fever situation in the mammalian host, the protein becomes essential. In contrast, depletion of mPrx in insect stage procyclic T. brucei causes a proliferation defect under standard conditions at 27 °C, in the absence of any stress. In the absence of mPrx, a tryparedoxin-coupled roGFP2 biosensor expressed in the mitochondrial matrix is unable to respond to antimycin A treatment. Thus mPrx reduces mitochondrial H2O2 with the generation of trypanothione disulfide and acts as peroxidase. However, mPrx-depleted procyclic cells neither display any alteration in the cytosolic or mitochondrial trypanothione redox state nor increased sensitivity towards exogenous oxidative stressors suggesting that the peroxidase activity is not the crucial physiological function. After prolonged mPrx-depletion, the cells almost stop proliferation and display a highly elongated shape and diminished MitoTracker Red staining. In contrast to the situation in the mammalian bloodstream T. brucei and Leishmania, mPrx appears to play a constitutive role for the morphology, mitochondrial function and proliferation of the insect stage of African trypanosomes. In bloodstream T. brucei, both mitochondrial tryparedoxin peroxidases are dispensable. Heat-stressed bloodstream cells require the mitochondrial peroxiredoxin (mPrx). In procyclic (PC) T. brucei, mPrx plays a constitutive role for proliferation. Lack of mPrx affects the structure and mitochondrial membrane potential of PC cells.
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Affiliation(s)
- Marta Bogacz
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Natalie Dirdjaja
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Benedikt Wimmer
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Carina Habich
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - R Luise Krauth-Siegel
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120, Heidelberg, Germany.
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Ebersoll S, Bogacz M, Günter LM, Dick TP, Krauth-Siegel RL. A tryparedoxin-coupled biosensor reveals a mitochondrial trypanothione metabolism in trypanosomes. eLife 2020; 9:53227. [PMID: 32003744 PMCID: PMC7046469 DOI: 10.7554/elife.53227] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/29/2020] [Indexed: 12/12/2022] Open
Abstract
Trypanosomes have a trypanothione redox metabolism that provides the reducing equivalents for numerous essential processes, most being mediated by tryparedoxin (Tpx). While the biosynthesis and reduction of trypanothione are cytosolic, the molecular basis of the thiol redox homeostasis in the single mitochondrion of these parasites has remained largely unknown. Here we expressed Tpx-roGFP2, roGFP2-hGrx1 or roGFP2 in either the cytosol or mitochondrion of Trypanosoma brucei. We show that the novel Tpx-roGFP2 is a superior probe for the trypanothione redox couple and that the mitochondrial matrix harbors a trypanothione system. Inhibition of trypanothione biosynthesis by the anti-trypanosomal drug Eflornithine impairs the ability of the cytosol and mitochondrion to cope with exogenous oxidative stresses, indicating a direct link between both thiol systems. Tpx depletion abolishes the cytosolic, but only partially affects the mitochondrial sensor response to H2O2. This strongly suggests that the mitochondrion harbors some Tpx and, another, as yet unidentified, oxidoreductase.
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Affiliation(s)
| | - Marta Bogacz
- Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
| | - Lina M Günter
- Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
| | - Tobias P Dick
- Division of Redox Regulation, DKFZ-ZMBH Alliance, German Cancer Research Center (DKFZ), Heidelberg, Germany
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10
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Castro H, Rocha MI, Silva R, Oliveira F, Gomes-Alves AG, Cruz T, Duarte M, Tomás AM. Functional insight into the glycosomal peroxiredoxin of Leishmania. Acta Trop 2020; 201:105217. [PMID: 31605692 DOI: 10.1016/j.actatropica.2019.105217] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/11/2019] [Accepted: 10/08/2019] [Indexed: 01/22/2023]
Abstract
Glycosomes of trypanosomatids are peroxisome-like organelles comprising unique metabolic features, among which the lack of the hallmark peroxisomal enzyme catalase. The absence of this highly efficient peroxidase from glycosomes is presumably compensated by other antioxidants, peroxidases of the peroxiredoxin (PRX) family being the most promising candidates for this function. Here, we follow on this premise and investigate the product of a Leishmania infantum gene coding for a putative glycosomal PRX (LigPRX). First, we demonstrate that LigPRX localizes to glycosomes, resorting to indirect immunofluorescence analysis. Second, we prove that purified recombinant LigPRX is an active peroxidase in vitro. Third, we generate viable LigPRX-depleted L. infantum promastigotes by classical homologous recombination. Surprisingly, phenotypic analysis of these knockout parasites revealed that promastigote survival, replication, and protection from oxidative and nitrosative insults can proceed normally in the absence of LigPRX. Noticeably, we also witness that LigPRX-depleted parasites can infect and thrive in mice to the same extent as wild type parasites. Overall, by disclosing the dispensable character of the glycosomal peroxiredoxin in L. infantum, this work excludes this enzyme from being a key component of the glycosomal hydroperoxide metabolism and contemplates alternative players for this function.
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Affiliation(s)
- Helena Castro
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal.
| | - Maria Inês Rocha
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Ricardo Silva
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Filipe Oliveira
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Ana Georgina Gomes-Alves
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Tânia Cruz
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Margarida Duarte
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Ana Maria Tomás
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
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11
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Currier RB, Ulrich K, Leroux AE, Dirdjaja N, Deambrosi M, Bonilla M, Ahmed YL, Adrian L, Antelmann H, Jakob U, Comini MA, Krauth-Siegel RL. An essential thioredoxin-type protein of Trypanosoma brucei acts as redox-regulated mitochondrial chaperone. PLoS Pathog 2019; 15:e1008065. [PMID: 31557263 PMCID: PMC6783113 DOI: 10.1371/journal.ppat.1008065] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 10/08/2019] [Accepted: 09/02/2019] [Indexed: 12/22/2022] Open
Abstract
Most known thioredoxin-type proteins (Trx) participate in redox pathways, using two highly conserved cysteine residues to catalyze thiol-disulfide exchange reactions. Here we demonstrate that the so far unexplored Trx2 from African trypanosomes (Trypanosoma brucei) lacks protein disulfide reductase activity but functions as an effective temperature-activated and redox-regulated chaperone. Immunofluorescence microscopy and fractionated cell lysis revealed that Trx2 is located in the mitochondrion of the parasite. RNA-interference and gene knock-out approaches showed that depletion of Trx2 impairs growth of both mammalian bloodstream and insect stage procyclic parasites. Procyclic cells lacking Trx2 stop proliferation under standard culture conditions at 27°C and are unable to survive prolonged exposure to 37°C, indicating that Trx2 plays a vital role that becomes augmented under heat stress. Moreover, we found that Trx2 contributes to the in vivo infectivity of T. brucei. Remarkably, a Trx2 version, in which all five cysteines were replaced by serine residues, complements for the wildtype protein in conditional knock-out cells and confers parasite infectivity in the mouse model. Characterization of the recombinant protein revealed that Trx2 can coordinate an iron sulfur cluster and is highly sensitive towards spontaneous oxidation. Moreover, we discovered that both wildtype and mutant Trx2 protect other proteins against thermal aggregation and preserve their ability to refold upon return to non-stress conditions. Activation of the chaperone function of Trx2 appears to be triggered by temperature-mediated structural changes and inhibited by oxidative disulfide bond formation. Our studies indicate that Trx2 acts as a novel chaperone in the unique single mitochondrion of T. brucei and reveal a new perspective regarding the physiological function of thioredoxin-type proteins in trypanosomes.
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Affiliation(s)
- Rachel B. Currier
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - Kathrin Ulrich
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | | | - Natalie Dirdjaja
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - Matías Deambrosi
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Mariana Bonilla
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
- Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | | | - Lorenz Adrian
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany
- Fachgebiet Geobiotechnologie, Technische Universität Berlin, Berlin, Germany
| | - Haike Antelmann
- Institut für Biologie-Mikrobiologie, Freie Universität Berlin, Berlin, Germany
| | - Ursula Jakob
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Marcelo A. Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
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12
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Zeida A, Trujillo M, Ferrer-Sueta G, Denicola A, Estrin DA, Radi R. Catalysis of Peroxide Reduction by Fast Reacting Protein Thiols. Chem Rev 2019; 119:10829-10855. [PMID: 31498605 DOI: 10.1021/acs.chemrev.9b00371] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Life on Earth evolved in the presence of hydrogen peroxide, and other peroxides also emerged before and with the rise of aerobic metabolism. They were considered only as toxic byproducts for many years. Nowadays, peroxides are also regarded as metabolic products that play essential physiological cellular roles. Organisms have developed efficient mechanisms to metabolize peroxides, mostly based on two kinds of redox chemistry, catalases/peroxidases that depend on the heme prosthetic group to afford peroxide reduction and thiol-based peroxidases that support their redox activities on specialized fast reacting cysteine/selenocysteine (Cys/Sec) residues. Among the last group, glutathione peroxidases (GPxs) and peroxiredoxins (Prxs) are the most widespread and abundant families, and they are the leitmotif of this review. After presenting the properties and roles of different peroxides in biology, we discuss the chemical mechanisms of peroxide reduction by low molecular weight thiols, Prxs, GPxs, and other thiol-based peroxidases. Special attention is paid to the catalytic properties of Prxs and also to the importance and comparative outlook of the properties of Sec and its role in GPxs. To finish, we describe and discuss the current views on the activities of thiol-based peroxidases in peroxide-mediated redox signaling processes.
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Affiliation(s)
| | | | | | | | - Darío A Estrin
- Departamento de Química Inorgánica, Analítica y Química-Física and INQUIMAE-CONICET , Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires , 2160 Buenos Aires , Argentina
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13
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Yagüe-Capilla M, García-Caballero D, Aguilar-Pereyra F, Castillo-Acosta VM, Ruiz-Pérez LM, Vidal AE, González-Pacanowska D. Base excision repair plays an important role in the protection against nitric oxide- and in vivo-induced DNA damage in Trypanosoma brucei. Free Radic Biol Med 2019; 131:59-71. [PMID: 30472364 DOI: 10.1016/j.freeradbiomed.2018.11.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 10/22/2018] [Accepted: 11/21/2018] [Indexed: 11/17/2022]
Abstract
Uracil-DNA glycosylase (UNG) initiates the base excision repair pathway by excising uracil from DNA. We have previously shown that Trypanosoma brucei cells defective in UNG exhibit reduced infectivity thus demonstrating the relevance of this glycosylase for survival within the mammalian host. In the early steps of the immune response, nitric oxide (NO) is released by phagocytes, which in combination with oxygen radicals produce reactive nitrogen species (RNS). These species can react with DNA generating strand breaks and base modifications including deaminations. Since deaminated cytosines are the main substrate for UNG, we hypothesized that the glycosylase might confer protection towards nitrosative stress. Our work establishes the occurrence of genotoxic damage in Trypanosoma brucei upon exposure to NO in vitro and shows that deficient base excision repair results in increased levels of damage in DNA and a hypermutator phenotype. We also evaluate the incidence of DNA damage during infection in vivo and show that parasites recovered from mice exhibit higher levels of DNA strand breaks, base deamination and repair foci compared to cells cultured in vitro. Notably, the absence of UNG leads to reduced infectivity and enhanced DNA damage also in animal infections. By analysing mRNA and protein levels, we found that surviving UNG-KO trypanosomes highly express tryparedoxin peroxidase involved in trypanothione/tryparedoxin metabolism. These observations suggest that the immune response developed by the host enhances the activation of genes required to counteract oxidative stress and emphasize the importance of DNA repair pathways in the protection to genotoxic and oxidative stress in trypanosomes.
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Affiliation(s)
- Miriam Yagüe-Capilla
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain
| | - Daniel García-Caballero
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain
| | - Fernando Aguilar-Pereyra
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain
| | - Víctor M Castillo-Acosta
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain
| | - Luis M Ruiz-Pérez
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain
| | - Antonio E Vidal
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain
| | - Dolores González-Pacanowska
- Instituto de Parasitología y Biomedicina "López-Neyra". Consejo Superior de Investigaciones Científicas. Parque Tecnológico de Ciencias de la Salud, Avenida del Conocimiento, 17, 18016 Armilla, Granada, Spain.
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14
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Bogacz M, Krauth-Siegel RL. Tryparedoxin peroxidase-deficiency commits trypanosomes to ferroptosis-type cell death. eLife 2018; 7:37503. [PMID: 30047863 PMCID: PMC6117152 DOI: 10.7554/elife.37503] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/24/2018] [Indexed: 01/19/2023] Open
Abstract
Tryparedoxin peroxidases, distant relatives of glutathione peroxidase 4 in higher eukaryotes, are responsible for the detoxification of lipid-derived hydroperoxides in African trypanosomes. The lethal phenotype of procyclic Trypanosoma brucei that lack the enzymes fulfils all criteria defining a form of regulated cell death termed ferroptosis. Viability of the parasites is preserved by α-tocopherol, ferrostatin-1, liproxstatin-1 and deferoxamine. Without protecting agent, the cells display, primarily mitochondrial, lipid peroxidation, loss of the mitochondrial membrane potential and ATP depletion. Sensors for mitochondrial oxidants and chelatable iron as well as overexpression of a mitochondrial iron-superoxide dismutase attenuate the cell death. Electron microscopy revealed mitochondrial matrix condensation and enlarged cristae. The peroxidase-deficient parasites are subject to lethal iron-induced lipid peroxidation that probably originates at the inner mitochondrial membrane. Taken together, ferroptosis is an ancient cell death program that can occur at individual subcellular membranes and is counterbalanced by evolutionary distant thiol peroxidases. Plants, animals and fungi all belong to a group of organisms known as eukaryotes. Their cells host a variety of compartments, with each having a specific role. For example, mitochondria are tasked with providing the energy that powers most of the processes that keep the cell alive. Membranes delimit these compartments, as well as the cells themselves. Iron is an element needed for chemical reactions that are essential for the cell to survive. Yet, the byproducts of these reactions can damage – ‘oxidize’ – the lipid molecules that form the cell’s membranes, including the one around mitochondria. Unless enzymes known as peroxidases come to repair the oxidized lipids, the cell dies in a process called ferroptosis. Scientists know that this death mechanism is programmed into the cells of humans and other complex eukaryotes. However, Bogacz and Krauth-Siegel wanted to know if ferroptosis also exists in creatures that appeared early in the evolution of eukaryotes, such as the trypanosome Trypanosoma brucei. This single-cell parasite causes sleeping sickness in humans and a disease called nagana in horses and cattle. Before it infects a mammal, T. brucei goes through an ‘insect stage’ where it lives in the tsetse fly; there, it relies on its mitochondrion to produce energy. Bogacz and Krauth-Siegel now show that if the parasites in the insect stage do not have a specific type of peroxidases, they die within a few hours. In particular, problems in the membranes of the mitochondrion stop the compartment from working properly. These peroxidases-free trypanosomes fare better if they are exposed to molecules that prevent iron from taking part in the reactions that can harm lipids. They also survive more if they are forced to create large amounts of an enzyme that relies on iron to protect the mitochondrion against oxidation. Finally, using drugs that prevent ferroptosis in human cells completely rescues these trypanosomes. Taken together, the results suggest that ferroptosis is an ancient cell death program which exists in T. brucei; and that, in the insect stage of the parasite's life cycle, this process first damages the mitochondrion. This last finding could be particularly relevant because the role of mitochondria in ferroptosis in mammals is highly debated. Yet, most of the research is done in cells that do not rely on this cellular compartment to get their energy. During their life cycle, trypanosomes are either dependent on their mitochondria, or they can find their energy through other sources: this could make them a good organism in which to dissect the precise mechanisms of ferroptosis.
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Affiliation(s)
- Marta Bogacz
- Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
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15
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Ebersoll S, Musunda B, Schmenger T, Dirdjaja N, Bonilla M, Manta B, Ulrich K, Comini MA, Krauth-Siegel RL. A glutaredoxin in the mitochondrial intermembrane space has stage-specific functions in the thermo-tolerance and proliferation of African trypanosomes. Redox Biol 2018; 15:532-547. [PMID: 29413965 PMCID: PMC5975080 DOI: 10.1016/j.redox.2018.01.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 01/23/2018] [Indexed: 12/30/2022] Open
Abstract
Trypanosoma brucei glutaredoxin 2 (Grx2) is a dithiol glutaredoxin that is specifically located in the mitochondrial intermembrane space. Bloodstream form parasites lacking Grx2 or both, Grx2 and the cytosolic Grx1, are viable in vitro and infectious to mice suggesting that neither oxidoreductase is needed for survival or infectivity to mammals. A 37 °C to 39 °C shift changes the cellular redox milieu of bloodstream cells to more oxidizing conditions and induces a significantly stronger growth arrest in wildtype parasites compared to the mutant cells. Grx2-deficient cells ectopically expressing the wildtype form of Grx2 with its C31QFC34 active site, but not the C34S mutant, regain the sensitivity of the parental strain, indicating that the physiological role of Grx2 requires both active site cysteines. In the procyclic insect stage of the parasite, Grx2 is essential. Both alleles can be replaced if procyclic cells ectopically express authentic or C34S, but not C31S/C34S Grx2, pointing to a redox role that relies on a monothiol mechanism. RNA-interference against Grx2 causes a virtually irreversible proliferation defect. The cells adopt an elongated morphology but do not show any significant alteration in the cell cycle. The growth retardation is attenuated by high glucose concentrations. Under these conditions, procyclic cells obtain ATP by substrate level phosphorylation suggesting that Grx2 might regulate a respiratory chain component. Bloodstream T. brucei lacking glutaredoxin 2 are fully viable in vitro and in vivo. A temperature rise shifts the cellular redox state to more oxidizing conditions. Glutaredoxin 2-deficiency confers bloodstream cells with thermo-tolerance. The insect stage requires redox-active glutaredoxin 2 for viability and morphology.
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Affiliation(s)
- Samantha Ebersoll
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Blessing Musunda
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Torsten Schmenger
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Natalie Dirdjaja
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Mariana Bonilla
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400, Montevideo, Uruguay
| | - Bruno Manta
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400, Montevideo, Uruguay
| | - Kathrin Ulrich
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Marcelo A Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400, Montevideo, Uruguay
| | - R Luise Krauth-Siegel
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
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16
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Guerrero SA, Arias DG, Cabeza MS, Law MCY, D'Amico M, Kumar A, Wilkinson SR. Functional characterisation of the methionine sulfoxide reductase repertoire in Trypanosoma brucei. Free Radic Biol Med 2017; 112:524-533. [PMID: 28865997 DOI: 10.1016/j.freeradbiomed.2017.08.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 08/10/2017] [Accepted: 08/29/2017] [Indexed: 12/22/2022]
Abstract
To combat the deleterious effects that oxidation of the sulfur atom in methionine to sulfoxide may bring, aerobic cells express repair pathways involving methionine sulfoxide reductases (MSRs) to reverse the above reaction. Here, we show that Trypanosoma brucei, the causative agent of African trypanosomiasis, expresses two distinct trypanothione-dependent MSRs that can be distinguished from each other based on sequence, sub-cellular localisation and substrate preference. One enzyme found in the parasite's cytosol, shows homology to the MSRA family of repair proteins and preferentially metabolises the S epimer of methionine sulfoxide. The second, which contains sequence motifs present in MSRBs, is restricted to the mitochondrion and can only catalyse reduction of the R form of peptide-bound methionine sulfoxide. The importance of these proteins to the parasite was demonstrated using functional genomic-based approaches to produce cells with reduced or elevated expression levels of MSRA, which exhibited altered susceptibility to exogenous H2O2. These findings identify new reparative pathways that function to fix oxidatively damaged methionine within this medically important parasite.
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Affiliation(s)
- Sergio A Guerrero
- Instituto de Agrobiotecnología del Litoral, CONICET-Universidad Nacional del Litoral, 3000 Santa Fe, Argentina
| | - Diego G Arias
- Instituto de Agrobiotecnología del Litoral, CONICET-Universidad Nacional del Litoral, 3000 Santa Fe, Argentina
| | - Matias S Cabeza
- Instituto de Agrobiotecnología del Litoral, CONICET-Universidad Nacional del Litoral, 3000 Santa Fe, Argentina
| | - Michelle C Y Law
- School of Biological & Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Maria D'Amico
- School of Biological & Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Ambika Kumar
- School of Biological & Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Shane R Wilkinson
- School of Biological & Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
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17
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Attacha S, Solbach D, Bela K, Moseler A, Wagner S, Schwarzländer M, Aller I, Müller SJ, Meyer AJ. Glutathione peroxidase-like enzymes cover five distinct cell compartments and membrane surfaces in Arabidopsis thaliana. PLANT, CELL & ENVIRONMENT 2017; 40:1281-1295. [PMID: 28102911 DOI: 10.1111/pce.12919] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 01/09/2017] [Accepted: 01/10/2017] [Indexed: 05/27/2023]
Abstract
Glutathione peroxidase-like enzymes (GPXLs) constitute a family of eight peroxidases in Arabidopsis thaliana. In contrast to the eponymous selenocysteine glutathione peroxidases in mammalian cells that use glutathione as electron donor, GPXLs rely on cysteine instead of selenocysteine for activity and depend on the thioredoxin system for reduction. Although plant GPXLs have been implicated in important agronomic traits such as drought tolerance, photooxidative tolerance and immune responses, there remain major ambiguities regarding their subcellular localization. Because their site of action is a prerequisite for an understanding of their function, we investigated the localization of all eight GPXLs in stable Arabidopsis lines expressing N-terminal and C-terminal fusions with redox-sensitive green fluorescent protein 2 (roGFP2) using confocal microscopy. GPXL1 and GPXL7 were found in plastids, while GPXL2 and GPXL8 are cytosolic nuclear. The N-terminal target peptide of GPXL6 is sufficient to direct roGFP2 into mitochondria. Interestingly, GPXL3, GPXL4 and GPXL5 all appear to be membrane bound. GPXL3 was found exclusively in the secretory pathway where it is anchored by a single N-terminal transmembrane domain. GPXL4 and GPXL5 are anchored to the plasma membrane. Presence of an N-terminal myristoylation motif and genetic disruption of membrane association through targeted mutagenesis point to myristoylation as essential for membrane localization.
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Affiliation(s)
- Safira Attacha
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
| | - David Solbach
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
| | - Krisztina Bela
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
- Department of Plant Biology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, H-6726, Szeged, Hungary
| | - Anna Moseler
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
| | - Stephan Wagner
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
| | - Markus Schwarzländer
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
| | - Isabel Aller
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
| | - Stefanie J Müller
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
| | - Andreas J Meyer
- INRES-Chemical Signalling, University of Bonn, Friedrich-Ebert-Allee 144, 53113, Bonn, Germany
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18
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Identification of potential protein partners that bind to the variant surface glycoprotein in Trypanosoma equiperdum. Parasitology 2017; 144:923-936. [DOI: 10.1017/s003118201700004x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
SUMMARYTrypanosoma equiperdum possesses a dense coat of a variant surface glycoprotein (VSG) that is used to evade the host immune response by a process known as antigenic variation. Soluble and membrane forms of the predominant VSG from the Venezuelan T. equiperdum TeAp-N/D1 strain (sVSG and mVSG, respectively) were purified to homogeneity; and antibodies against sVSG and mVSG were raised, isolated, and employed to produce anti-idiotypic antibodies that structurally mimic the VSG surface. Prospective VSG-binding partners were initially detected by far-Western blots, and then by immunoblots using the generated anti-idiotypic antibodies. Polypeptides of ~80 and 55 kDa were isolated when anti-idiotypic antibodies–Sepharose affinity matrixes were used as baits. Mass spectrometry sequencing yielded hits with various proteins from Trypanosoma brucei such as heat-shock protein 70, tryparedoxin peroxidase, VSG variants, expression site associated gene product 6, and two hypothetical proteins. In addition, a possible interaction with a protein homologous to the glutamic acid/alanine-rich protein from Trypanosoma congolense was also found. These results indicate that the corresponding orthologous gene products are candidates for VSG-interacting proteins in T. equiperdum.
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Beltrame-Botelho IT, Talavera-López C, Andersson B, Grisard EC, Stoco PH. A Comparative In Silico Study of the Antioxidant Defense Gene Repertoire of Distinct Lifestyle Trypanosomatid Species. Evol Bioinform Online 2016; 12:263-275. [PMID: 27840574 PMCID: PMC5100842 DOI: 10.4137/ebo.s40648] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 10/05/2016] [Accepted: 10/11/2016] [Indexed: 12/24/2022] Open
Abstract
Kinetoplastids are an ancestral group of protists that contains free-living species and parasites with distinct mechanisms in response to stress. Here, we compared genes involved in antioxidant defense (AD), proposing an evolution model among trypanosomatids. All genes were identified in Bodo saltans, suggesting that AD mechanisms have evolved prior to adaptation for parasitic lifestyles. While most of the monoxenous and dixenous parasites revealed minor differences from B. saltans, the endosymbiont-bearing species have an increased number of genes. The absence of these genes was mainly observed in the extracellular parasites of the genera Phytomonas and Trypanosoma. In trypanosomes, a distinction was observed between stercorarian and salivarian parasites, except for Trypanosoma rangeli. Our analyses indicate that the variability of AD among trypanosomatids at the genomic level is not solely due to the geographical isolation, being mainly related to specific adaptations of their distinct biological cycles within insect vectors and to a parasitism of a wide range of hosts.
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Affiliation(s)
- Ingrid Thaís Beltrame-Botelho
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
- Universidade do Sul de Santa Catarina, Palhoça, SC, Brazil
| | | | - Björn Andersson
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Edmundo Carlos Grisard
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Patricia Hermes Stoco
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
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20
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Arias DG, Herrera FE, Garay AS, Rodrigues D, Forastieri PS, Luna LE, Bürgi MDLM, Prieto C, Iglesias AA, Cravero RM, Guerrero SA. Rational design of nitrofuran derivatives: Synthesis and valuation as inhibitors of Trypanosoma cruzi trypanothione reductase. Eur J Med Chem 2016; 125:1088-1097. [PMID: 27810595 DOI: 10.1016/j.ejmech.2016.10.055] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/28/2016] [Accepted: 10/23/2016] [Indexed: 12/21/2022]
Abstract
The rational design and synthesis of a series of 5-nitro-2-furoic acid analogues are presented. The trypanocidal activity against epimastigote forms of Trypanosoma cruzi and the toxic effects on human HeLa cells were tested. Between all synthetic compounds, three of thirteen had an IC50 value in the range of Nfx, but compound 13 exhibited an improved effect with an IC50 of 1.0 ± 0.1 μM and a selective index of 70 in its toxicity against HeLa cells. We analyzed the activity of compounds 8, 12 and 13 to interfere in the central redox metabolic pathway in trypanosomatids, which is dependent of reduced trypanothione as the major pivotal thiol. The three compounds behaved as better inhibitors of trypanothione reductase than Nfx (Ki values of 118 μM, 61 μM and 68 μM for 8, 12 and 13, respectively, compared with 245 μM for Nfx), all following an uncompetitive enzyme inhibition pattern. Docking analysis predicted a binding of inhibitors to the enzyme-substrate complex with binding energy calculated in-silico that supports such molecular interaction.
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Affiliation(s)
- D G Arias
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Argentina; Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - F E Herrera
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - A S Garay
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - D Rodrigues
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - P S Forastieri
- Instituto de Química Rosario (CONICET) - FCByF- Universidad Nacional de Rosario, Argentina
| | - L E Luna
- Instituto de Química Rosario (CONICET) - FCByF- Universidad Nacional de Rosario, Argentina
| | - M D L M Bürgi
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - C Prieto
- Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - A A Iglesias
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Argentina; Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Argentina
| | - R M Cravero
- Instituto de Química Rosario (CONICET) - FCByF- Universidad Nacional de Rosario, Argentina
| | - S A Guerrero
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Argentina; Facultad Regional Santa Fe, Universidad Tecnológica Nacional (UTN), Argentina.
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21
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Biochemical and biophysical characterization of Leishmania donovani gamma-glutamylcysteine synthetase. Biochem Biophys Rep 2016; 8:127-138. [PMID: 28955948 PMCID: PMC5613772 DOI: 10.1016/j.bbrep.2016.08.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/02/2016] [Accepted: 08/14/2016] [Indexed: 12/03/2022] Open
Abstract
γ-glutamylcysteine synthetase (Gcs) is a vital enzyme catalyzing the first and rate limiting step in the trypanothione biosynthesis pathway, the ATP-dependent ligation of L-Glutamate and L-Cysteine to form gamma-glutamylcysteine. The Trypanothione biosynthesis pathway is unique metabolic pathway essential for trypanosomatid survival rendering Gcs as a potential drug target. Here we report the cloning, expression, purification and characterization of L. donovani Gcs. Three other constructs of Gcs (GcsN, GcsC and GcsT) were designed on the basis of S. cerevisiae and E. coli Gcs crystal structures. The study shows Gcs possesses ATPase activity even in the absence of substrates L-glutamate and L-Cysteine. Divalent ions however plays an indispensable role in LdGcs ATPase activity. Isothermal titration calorimetry and fluorescence studies illustrates that L. donovani Gcs binds substrate in order ATP >L-glutamate>L-cysteine with Glu 92 and Arg 498 involved in ATP hydrolysis and Glu 92, Glu 55 and Arg 498 involved in glutamate binding. Homology modeling and molecular dynamic simulation studies provided the structural rationale of LdGcs catalytic activity and emphasized on the possibility of involvement of three Mg2+ ions along with Glutamates 52, 55, 92, 99, Met 322, Gln 328, Tyr 397, Lys 483, Arg 494 and Arg 498 in the catalytic function of L. donovani Gcs. L. donovani Gamma glutamylcysteine synthetase is a divalent dependent ATPase. Substrate binds in order ATP>> L-Glutamate> L-cysteine. Glu 92 and Arg 498 involved in ATP hydrolysis. Glu 92, Glu 55 and Arg 498 involved in glutamate binding.
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22
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Liu I, Bogacz M, Schaffroth C, Dirdjaja N, Krauth-Siegel RL. Catalytic properties, localization, and in vivo role of Px IV, a novel tryparedoxin peroxidase of Trypanosoma brucei. Mol Biochem Parasitol 2016; 207:84-8. [PMID: 27262262 DOI: 10.1016/j.molbiopara.2016.05.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 05/27/2016] [Accepted: 05/31/2016] [Indexed: 10/21/2022]
Abstract
Px IV is a distant relative of the known glutathione peroxidase-type enzymes of African trypanosomes. Immunofluorescence microscopy of bloodstream cells expressing C-terminally Myc6-tagged Px IV revealed a mitochondrial localization. Recombinant Px IV possesses very low activity as glutathione peroxidase but catalyzes the trypanothione/tryparedoxin-dependent reduction of hydrogen peroxide and, even more efficiently, of arachidonic acid hydroperoxide. Neither overexpression in bloodstream cells nor the deletion of both alleles in bloodstream or procyclic parasites affected the in vitro proliferation. Trypanosoma brucei Px IV shares 58% of all residues with TcGPXII. The orthologous enzymes have in common their substrate preference for fatty acid hydroperoxides. However, the T. cruzi protein has been reported to be localized in the endoplasmic reticulum and to be specific for glutathione as reducing agent. Taken together, our data show that Px IV is a low abundant tryparedoxin peroxidase of T. brucei that is not essential, at least under culture conditions.
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Affiliation(s)
- Ilon Liu
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Marta Bogacz
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Corinna Schaffroth
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Natalie Dirdjaja
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - R Luise Krauth-Siegel
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
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23
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Faria J, Loureiro I, Santarém N, Cecílio P, Macedo-Ribeiro S, Tavares J, Cordeiro-da-Silva A. Disclosing the essentiality of ribose-5-phosphate isomerase B in Trypanosomatids. Sci Rep 2016; 6:26937. [PMID: 27230471 PMCID: PMC4882579 DOI: 10.1038/srep26937] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 05/10/2016] [Indexed: 01/31/2023] Open
Abstract
Ribose-5-phosphate isomerase (RPI) belongs to the non-oxidative branch of the pentose phosphate pathway, catalysing the inter-conversion of D-ribose-5-phosphate and D-ribulose-5-phosphate. Trypanosomatids encode a type B RPI, whereas humans have a structurally unrelated type A, making RPIB worthy of exploration as a potential drug target. Null mutant generation in Leishmania infantum was only possible when an episomal copy of RPIB gene was provided, and the latter was retained both in vitro and in vivo in the absence of drug pressure. This suggests the gene is essential for parasite survival. Importantly, the inability to remove the second allele of RPIB gene in sKO mutants complemented with an episomal copy of RPIB carrying a mutation that abolishes isomerase activity suggests the essentiality is due to its metabolic function. In vitro, sKO promastigotes exhibited no defect in growth, metacyclogenesis or macrophage infection, however, an impairment in intracellular amastigotes' replication was observed. Additionally, mice infected with sKO mutants rescued by RPIB complementation had a reduced parasite burden in the liver. Likewise, Trypanosoma brucei is resistant to complete RPIB gene removal and mice infected with sKO mutants showed prolonged survival upon infection. Taken together our results genetically validate RPIB as a potential drug target in trypanosomatids.
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Affiliation(s)
- Joana Faria
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Inês Loureiro
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Nuno Santarém
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Pedro Cecílio
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Sandra Macedo-Ribeiro
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Protein Crystallography Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal
| | - Joana Tavares
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
| | - Anabela Cordeiro-da-Silva
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Portugal
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Portugal
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Musunda B, Benítez D, Dirdjaja N, Comini MA, Krauth-Siegel RL. Glutaredoxin-deficiency confers bloodstream Trypanosoma brucei with improved thermotolerance. Mol Biochem Parasitol 2016; 204:93-105. [PMID: 26854591 DOI: 10.1016/j.molbiopara.2016.02.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 02/02/2016] [Accepted: 02/03/2016] [Indexed: 12/16/2022]
Abstract
As constituents of their unusual trypanothione-based thiol metabolism, African trypanosomes express two dithiol glutaredoxins (Grxs), a cytosolic Grx1 and a mitochondrial Grx2, with so far unknown biological functions. As revealed by gel shift assays, in the mammalian bloodstream form of Trypanosoma brucei, Grx1 is in the fully reduced state. Upon diamide treatment of the cells, Grx1 forms an active site disulfide bridge that is rapidly re-reduced after stress removal; Cys76, a conserved non-active site Cys remains in the thiol state. Deletion of both grx1 alleles does not result in any proliferation defect of neither the procyclic insect form nor the bloodstream form, even not under various stress conditions. In addition, the Grx1-deficient parasites are fully infectious in the mouse model. A functional compensation by Grx2 is unlikely as identical levels of Grx2 were found in wildtype and Grx1-deficient cells. In the classical hydroxyethyl disulfide assay, Grx1-deficient bloodstream cells display 50-60% of the activity of wildtype cells indicating that the cytosolic oxidoreductase accounts for a major part of the total deglutathionylation capacity of the parasite. Intriguingly, at elevated temperature, proliferation of the Grx1-deficient bloodstream parasites is significantly less affected compared to wildtype cells. When cultured for three days at 39°C, only 51% of the cells in the wildtype population retained normal morphology with single mitochondrial and nuclear DNA (1K1N), whereas 27% of the cells displayed ≥2K2N. In comparison, 64% of the Grx1-deficient cells kept the 1K1N phenotype and only 18% had ≥2K2N. The data suggest that Grx1 plays a role in the regulation of the thermotolerance of the parasites by (in)directly interfering with the progression of the cell cycle, a process that may comprise protein (de)glutathionylation step(s).
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Affiliation(s)
- Blessing Musunda
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Diego Benítez
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400 Montevideo, Uruguay
| | - Natalie Dirdjaja
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Marcelo A Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400 Montevideo, Uruguay
| | - R Luise Krauth-Siegel
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
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25
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Schaffroth C, Bogacz M, Dirdjaja N, Nißen A, Krauth-Siegel RL. The cytosolic or the mitochondrial glutathione peroxidase-type tryparedoxin peroxidase is sufficient to protect procyclic Trypanosoma brucei from iron-mediated mitochondrial damage and lysis. Mol Microbiol 2015; 99:172-87. [PMID: 26374473 DOI: 10.1111/mmi.13223] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2015] [Indexed: 01/15/2023]
Abstract
African trypanosomes express three virtually identical glutathione peroxidase (Px)-type enzymes that occur in the cytosol (Px I and II) and mitochondrion (Px III) and detoxify fatty acid-derived hydroperoxides. Selective deletion of the genes revealed that procyclic Trypanosoma brucei lacking either the cytosolic or mitochondrial enzyme proliferate nearly as wild-type parasites, whereas the knockout of the complete genomic locus is lethal. Flow cytometry and immunofluorescence analyses revealed that the Px I-III-deficient parasites lose their mitochondrial membrane potential, which is followed by a loss of the lysosomal signal but not the glycosomal one. Mitochondrial damage and cell lysis are prevented by Trolox, ubiquinone derivatives and the iron chelator deferoxamine, whereas starch-deferoxamine is inefficient. In glucose-rich medium, cell death is attenuated suggesting that oxidants generated by the respiratory chain contribute to the lethal phenotype. Thus, the Px-type peroxidases protect procyclic cells from an iron-mediated oxidative membrane damage that originates at the mitochondrion. This contrasts with the situation in bloodstream cells, where the lysosome is the primarily affected organelle. Strikingly, either the cytosolic or the mitochondrial form of the peroxidases is required and sufficient to protect the mitochondrion and prevent cell lysis.
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Affiliation(s)
- Corinna Schaffroth
- Biochemie-Zentrum der Universität Heidelberg (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Marta Bogacz
- Biochemie-Zentrum der Universität Heidelberg (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Natalie Dirdjaja
- Biochemie-Zentrum der Universität Heidelberg (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - Amrei Nißen
- Biochemie-Zentrum der Universität Heidelberg (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
| | - R Luise Krauth-Siegel
- Biochemie-Zentrum der Universität Heidelberg (BZH), Im Neuenheimer Feld 328, 69120, Heidelberg, Germany
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26
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Beig M, Oellien F, Garoff L, Noack S, Krauth-Siegel RL, Selzer PM. Trypanothione reductase: a target protein for a combined in vitro and in silico screening approach. PLoS Negl Trop Dis 2015; 9:e0003773. [PMID: 26042772 PMCID: PMC4456413 DOI: 10.1371/journal.pntd.0003773] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 04/21/2015] [Indexed: 12/04/2022] Open
Abstract
With the goal to identify novel trypanothione reductase (TR) inhibitors, we performed a combination of in vitro and in silico screening approaches. Starting from a highly diverse compound set of 2,816 compounds, 21 novel TR inhibiting compounds could be identified in the initial in vitro screening campaign against T. cruzi TR. All 21 in vitro hits were used in a subsequent similarity search-based in silico screening on a database containing 200,000 physically available compounds. The similarity search resulted in a data set containing 1,204 potential TR inhibitors, which was subjected to a second in vitro screening campaign leading to 61 additional active compounds. This corresponds to an approximately 10-fold enrichment compared to the initial pure in vitro screening. In total, 82 novel TR inhibitors with activities down to the nM range could be identified proving the validity of our combined in vitro/in silico approach. Moreover, the four most active compounds, showing IC50 values of <1 μM, were selected for determining the inhibitor constant. In first on parasites assays, three compounds inhibited the proliferation of bloodstream T. brucei cell line 449 with EC50 values down to 2 μM.
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Affiliation(s)
- Mathias Beig
- MSD Animal Health Innovation GmbH, Zur Propstei, Schwabenheim, Germany
| | - Frank Oellien
- MSD Animal Health Innovation GmbH, Zur Propstei, Schwabenheim, Germany
| | - Linnéa Garoff
- Universität Heidelberg, Biochemie-Zentrum (BZH), Heidelberg, Germany
| | - Sandra Noack
- MSD Animal Health Innovation GmbH, Zur Propstei, Schwabenheim, Germany
| | | | - Paul M. Selzer
- MSD Animal Health Innovation GmbH, Zur Propstei, Schwabenheim, Germany
- Universität Tübingen, Interfakultäres Institut für Biochemie, Tübingen, Germany
- Wellcome Trust Centre for Molecular Parasitology, Division of Infection, Immunity and Inflammation, Faculty of Biomedical & Life Sciences, University of Glasgow, Glasgow, United Kingdom
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27
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Loureiro I, Faria J, Clayton C, Macedo-Ribeiro S, Santarém N, Roy N, Cordeiro-da-Siva A, Tavares J. Ribose 5-phosphate isomerase B knockdown compromises Trypanosoma brucei bloodstream form infectivity. PLoS Negl Trop Dis 2015; 9:e3430. [PMID: 25568941 PMCID: PMC4287489 DOI: 10.1371/journal.pntd.0003430] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 11/21/2014] [Indexed: 12/13/2022] Open
Abstract
Ribose 5-phosphate isomerase is an enzyme involved in the non-oxidative branch of the pentose phosphate pathway, and catalyzes the inter-conversion of D-ribose 5-phosphate and D-ribulose 5-phosphate. Trypanosomatids, including the agent of African sleeping sickness namely Trypanosoma brucei, have a type B ribose-5-phosphate isomerase. This enzyme is absent from humans, which have a structurally unrelated ribose 5-phosphate isomerase type A, and therefore has been proposed as an attractive drug target waiting further characterization. In this study, Trypanosoma brucei ribose 5-phosphate isomerase B showed in vitro isomerase activity. RNAi against this enzyme reduced parasites' in vitro growth, and more importantly, bloodstream forms infectivity. Mice infected with induced RNAi clones exhibited lower parasitaemia and a prolonged survival compared to control mice. Phenotypic reversion was achieved by complementing induced RNAi clones with an ectopic copy of Trypanosoma cruzi gene. Our results present the first functional characterization of Trypanosoma brucei ribose 5-phosphate isomerase B, and show the relevance of an enzyme belonging to the non-oxidative branch of the pentose phosphate pathway in the context of Trypanosoma brucei infection. Within the non-oxidative branch of the pentose phosphate pathway, ribose 5-phosphate isomerase catalyzes the inter-conversion of ribose 5-phosphate and ribulose 5-phosphate. There are two types of ribose 5-phosphate isomerase, namely A and B. The presence of type B in Trypanosoma brucei, and its absence in humans, make this protein a promising drug target. African sleeping sickness is a serious parasitic disease that relies on limited chemotherapeutic options for control. In our study, a functional characterization of Trypanosoma brucei ribose 5-phosphate isomerase B is reported. Biochemical studies confirmed enzyme isomerase activity and its downregulation by RNAi affected mainly parasites infectivity in vivo. Overall this study shows that ribose 5-phosphate isomerase depletion is detrimental for parasites infectivity under host pressure.
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Affiliation(s)
- Inês Loureiro
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal
| | - Joana Faria
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal
| | - Christine Clayton
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH cv Alliance, Heidelberg, Germany
| | - Sandra Macedo-Ribeiro
- Protein Crystallography Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal
| | - Nuno Santarém
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal
| | - Nilanjan Roy
- Ashok & Rita Patel Institute of Integrated Study & Research in Biotechnology & Allied Sciences, New Vallabh Vidyanagar, Dist-Anand, Gujarat, India
| | - Anabela Cordeiro-da-Siva
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal
- Departamento de Ciências Biológicas, Faculdade de Farmácia da Universidade do Porto, Porto, Portugal
- * E-mail: (ACdS); (JT)
| | - Joana Tavares
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal
- * E-mail: (ACdS); (JT)
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Hiller C, Nissen A, Benítez D, Comini MA, Krauth-Siegel RL. Cytosolic peroxidases protect the lysosome of bloodstream African trypanosomes from iron-mediated membrane damage. PLoS Pathog 2014; 10:e1004075. [PMID: 24722489 PMCID: PMC3983053 DOI: 10.1371/journal.ppat.1004075] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 03/02/2014] [Indexed: 01/23/2023] Open
Abstract
African trypanosomes express three virtually identical non-selenium glutathione peroxidase (Px)-type enzymes which preferably detoxify lipid-derived hydroperoxides. As shown previously, bloodstream Trypanosoma brucei lacking the mitochondrial Px III display only a weak and transient proliferation defect whereas parasites that lack the cytosolic Px I and Px II undergo extremely fast lipid peroxidation and cell lysis. The phenotype can completely be rescued by supplementing the medium with the α-tocopherol derivative Trolox. The mechanism underlying the rapid cell death remained however elusive. Here we show that the lysosome is the origin of the cellular injury. Feeding the px I–II knockout parasites with Alexa Fluor-conjugated dextran or LysoTracker in the presence of Trolox yielded a discrete lysosomal staining. Yet upon withdrawal of the antioxidant, the signal became progressively spread over the whole cell body and was completely lost, respectively. T. brucei acquire iron by endocytosis of host transferrin. Supplementing the medium with iron or transferrin induced, whereas the iron chelator deferoxamine and apo-transferrin attenuated lysis of the px I–II knockout cells. Immunofluorescence microscopy with MitoTracker and antibodies against the lysosomal marker protein p67 revealed that disintegration of the lysosome precedes mitochondrial damage. In vivo experiments confirmed the negligible role of the mitochondrial peroxidase: Mice infected with px III knockout cells displayed only a slightly delayed disease development compared to wild-type parasites. Our data demonstrate that in bloodstream African trypanosomes, the lysosome, not the mitochondrion, is the primary site of oxidative damage and cytosolic trypanothione/tryparedoxin-dependent peroxidases protect the lysosome from iron-induced membrane peroxidation. This process appears to be closely linked to the high endocytic rate and distinct iron acquisition mechanisms of the infective stage of T. brucei. The respective knockout of the cytosolic px I–II in the procyclic insect form resulted in cells that were fully viable in Trolox-free medium. In many cell types, mitochondria are the main source of intracellular reactive oxygen species but iron-induced oxidative lysosomal damage has been described as well. African trypanosomes are the causative agents of human sleeping sickness and the cattle disease Nagana. The parasites are obligate extracellular pathogens that multiply in the bloodstream and body fluids of their mammalian hosts and as procyclic forms in their insect vector, the tsetse fly. Bloodstream Trypanosoma brucei in which the genes for cytosolic lipid hydroperoxide-detoxifying peroxidases have been knocked out undergo an extremely rapid membrane peroxidation and lyse within less than two hours when they are cultured without an exogenous antioxidant. Here we show that the primary site of intracellular damage is the single terminal lysosome of the parasites. Disintegration of the lysosome clearly precedes damage of the mitochondrion and parasite death. Iron, acquired by the endocytosis of iron-loaded host transferrin, induces cell lysis. Contrary to the cytosolic enzymes, the respective mitochondrial peroxidase is dispensable for both in vitro proliferation and mouse infectivity. This is the first report demonstrating that cytosolic thiol peroxidases are responsible for protecting the lysosome of a cell.
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Affiliation(s)
- Corinna Hiller
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - Amrei Nissen
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - Diego Benítez
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Marcelo A. Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
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Loureiro I, Faria J, Clayton C, Ribeiro SM, Roy N, Santarém N, Tavares J, Cordeiro-da-Silva A. Knockdown of asparagine synthetase A renders Trypanosoma brucei auxotrophic to asparagine. PLoS Negl Trop Dis 2013; 7:e2578. [PMID: 24340117 PMCID: PMC3854871 DOI: 10.1371/journal.pntd.0002578] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 10/25/2013] [Indexed: 11/29/2022] Open
Abstract
Asparagine synthetase (AS) catalyzes the ATP-dependent conversion of aspartate into asparagine using ammonia or glutamine as nitrogen source. There are two distinct types of AS, asparagine synthetase A (AS-A), known as strictly ammonia-dependent, and asparagine synthetase B (AS-B), which can use either ammonia or glutamine. The absence of AS-A in humans, and its presence in trypanosomes, suggested AS-A as a potential drug target that deserved further investigation. We report the presence of functional AS-A in Trypanosoma cruzi (TcAS-A) and Trypanosoma brucei (TbAS-A): the purified enzymes convert L-aspartate into L-asparagine in the presence of ATP, ammonia and Mg2+. TcAS-A and TbAS-A use preferentially ammonia as a nitrogen donor, but surprisingly, can also use glutamine, a characteristic so far never described for any AS-A. TbAS-A knockdown by RNAi didn't affect in vitro growth of bloodstream forms of the parasite. However, growth was significantly impaired when TbAS-A knockdown parasites were cultured in medium with reduced levels of asparagine. As expected, mice infections with induced and non-induced T. brucei RNAi clones were similar to those from wild-type parasites. However, when induced T. brucei RNAi clones were injected in mice undergoing asparaginase treatment, which depletes blood asparagine, the mice exhibited lower parasitemia and a prolonged survival in comparison to similarly-treated mice infected with control parasites. Our results show that TbAS-A can be important under in vivo conditions when asparagine is limiting, but is unlikely to be suitable as a drug target. The amino acid asparagine is important not only for protein biosynthesis, but also for nitrogen homeostasis. Asparagine synthetase catalyzes the synthesis of this amino acid. There are two forms of asparagine synthetase, A and B. The presence of type A in trypanosomes, and its absence in humans, makes this protein a potential drug target. Trypanosomes are responsible for serious parasitic diseases that rely on limited drug therapeutic options for control. In our study we present a functional characterization of trypanosomes asparagine synthetase A. We describe that Trypanosoma brucei and Trypanosoma cruzi type A enzymes are able to use either ammonia or glutamine as a nitrogen donor, within the conversion of aspartate into asparagine. Furthermore, we show that asparagine synthetase A knockdown renders Trypanosoma brucei auxotrophic to asparagine. Overall, this study demonstrates that interfering with asparagine metabolism represents a way to control parasite growth and infectivity.
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Affiliation(s)
- Inês Loureiro
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal
| | - Joana Faria
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal
| | - Christine Clayton
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Sandra Macedo Ribeiro
- Protein Crystallography Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal
| | - Nilanjan Roy
- Ashok and Rita Patel Institute of Integrated Study and Research in Biotechnology and Allied Sciences, New Vallabh Vidyanagar, Gujarat, India
| | - Nuno Santarém
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal
| | - Joana Tavares
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal
- * E-mail: (JT); (ACdS)
| | - Anabela Cordeiro-da-Silva
- Parasite Disease Group, Instituto de Biologia Molecular e Celular da Universidade do Porto, Porto, Portugal
- Departamento de Ciências Biológicas, Faculdade de Farmácia da Universidade do Porto, Porto, Portugal
- * E-mail: (JT); (ACdS)
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Arias DG, Marquez VE, Chiribao ML, Gadelha FR, Robello C, Iglesias AA, Guerrero SA. Redox metabolism in Trypanosoma cruzi: functional characterization of tryparedoxins revisited. Free Radic Biol Med 2013; 63:65-77. [PMID: 23665397 DOI: 10.1016/j.freeradbiomed.2013.04.036] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 04/04/2013] [Accepted: 04/30/2013] [Indexed: 01/01/2023]
Abstract
Tryparedoxins (TXNs) are multipurpose oxidoreductases from trypanosomatids that transfer reducing equivalents from trypanothione to various thiol proteins. In Trypanosoma cruzi, two genes coding for TXN-like proteins have been identified: TXNI, previously characterized as a cytoplasmic protein, and TXNII, a putative tail-anchored membrane protein. In this work, we performed a comparative functional characterization of T. cruzi TXNs. Particularly, we cloned the gene region coding for the soluble version of TXNII for its heterologous expression. The truncated recombinant protein (without its 22 C-terminal transmembrane amino acids) showed TXN activity. It was also able to transfer reducing equivalents from trypanothione, glutathione, or dihydrolipoamide to various acceptors, including methionine sulfoxide reductases and peroxiredoxins. The results support the occurrence and functionality of a second tryparedoxin, which appears as a new component in the redox scenario for T. cruzi.
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Affiliation(s)
- Diego G Arias
- Instituto de Agrobiotecnología del Litoral, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral-CONICET, 3000 Santa Fe, Argentina
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31
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Comini MA, Krauth-Siegel RL, Bellanda M. Mono- and dithiol glutaredoxins in the trypanothione-based redox metabolism of pathogenic trypanosomes. Antioxid Redox Signal 2013; 19:708-22. [PMID: 22978520 PMCID: PMC3739957 DOI: 10.1089/ars.2012.4932] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
SIGNIFICANCE Glutaredoxins are ubiquitous small thiol proteins of the thioredoxin-fold superfamily. Two major groups are distinguished based on their active sites: the dithiol (2-C-Grxs) and the monothiol (1-C-Grxs) glutaredoxins with a CXXC and a CXXS active site motif, respectively. Glutaredoxins are involved in cellular redox and/or iron sulfur metabolism. Usually their functions are closely linked to the glutathione system. Trypanosomatids, the causative agents of several tropical diseases, rely on trypanothione as principal low molecular mass thiol, and their glutaredoxins readily react with the unique bis(glutathionyl) spermidine conjugate. RECENT ADVANCES Two 2-C-Grxs and three 1-C-Grxs have been identified in pathogenic trypanosomatids. The 2-C-Grxs catalyze the reduction of glutathione disulfide by trypanothione and display reductase activity towards protein disulfides, as well as protein-glutathione mixed disulfides. In vitro, all three 1-C-Grxs as well as the cytosolic 2-C-Grx of Trypanosoma brucei can complex an iron-sulfur cluster. Recently the structure of the 1-C-Grx1 has been solved by NMR spectroscopy. The structure is very similar to those of other 1-C-Grxs, with some differences in the loop containing the conserved cis-Pro and the surface charge distribution. CRITICAL ISSUES Although four of the five trypanosomal glutaredoxins proved to coordinate an iron-sulfur cluster in vitro, the physiological role of the mitochondrial and cytosolic proteins, respectively, has only started to be unraveled. FUTURE DIRECTIONS The use of trypanothione by the glutaredoxins has established a novel role for this parasite-specific dithiol. Future work should reveal if these differences can be exploited for the development of novel antiparasitic drugs.
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Affiliation(s)
- Marcelo A Comini
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay.
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Abstract
SIGNIFICANCE In the single mitochondrion of protozoan trypanosomatid parasites there are several sites for the generation and elimination of reactive oxygen species (ROS), a class of molecules that exhibit a dual role in cells, either as regulatory mediators or as cytotoxic effectors. RECENT ADVANCES Formation of ROS in trypanosomatid mitochondria can be induced by various drug compounds. Importantly, it can also be triggered by specific physiologic stimuli, indicating that this phenomenon may occur in living parasites as well. Elimination of ROS in these organelles is attributed to the activity of two iron-dependent superoxide dismutases (FeSODs) and up to three different peroxidases (a cytochrome c peroxidase and two thiol peroxidases). CRITICAL ISSUES Data regarding the formation of ROS in trypanosomatid mitochondria are limited and nonsystematic. Another critical issue refers to the exact contribution of mitochondrial FeSODs and peroxidases for ROS removal, given that their antioxidant activity is not essential when abrogated individually. This suggests some level of functional overlapping or that ROS produced in mitochondria under normal conditions can be removed noncatalytically. Also still unsolved is the mechanism by which mitochondrial thiol peroxidases are regenerated to their reduced (active) form. FUTURE DIRECTIONS The production of intramitochondrial ROS under physiologic conditions and their implication in parasite biology should be further clarified. The relative importance of enzymatic versus nonenzymatic mechanisms for ROS elimination in trypanosomatid mitochondria also requires investigation. Simultaneous depletion of several redundant antioxidant enzymes and determination of noncatalytic antioxidants are possible ways to achieve this.
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Affiliation(s)
- Ana M Tomás
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.
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Lu J, Vodnala SK, Gustavsson AL, Gustafsson TN, Sjöberg B, Johansson HA, Kumar S, Tjernberg A, Engman L, Rottenberg ME, Holmgren A. Ebsulfur is a benzisothiazolone cytocidal inhibitor targeting the trypanothione reductase of Trypanosoma brucei. J Biol Chem 2013; 288:27456-27468. [PMID: 23900839 DOI: 10.1074/jbc.m113.495101] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trypanosoma brucei is the causing agent of African trypanosomiasis. These parasites possess a unique thiol redox system required for DNA synthesis and defense against oxidative stress. It includes trypanothione and trypanothione reductase (TryR) instead of the thioredoxin and glutaredoxin systems of mammalian hosts. Here, we show that the benzisothiazolone compound ebsulfur (EbS), a sulfur analogue of ebselen, is a potent inhibitor of T. brucei growth with a favorable selectivity index over mammalian cells. EbS inhibited the TryR activity and decreased non-protein thiol levels in cultured parasites. The inhibition of TryR by EbS was irreversible and NADPH-dependent. EbS formed a complex with TryR and caused oxidation and inactivation of the enzyme. EbS was more toxic for T. brucei than for Trypanosoma cruzi, probably due to lower levels of TryR and trypanothione in T. brucei. Furthermore, inhibition of TryR produced high intracellular reactive oxygen species. Hydrogen peroxide, known to be constitutively high in T. brucei, enhanced the EbS inhibition of TryR. The elevation of reactive oxygen species production in parasites caused by EbS induced a programmed cell death. Soluble EbS analogues were synthesized and cured T. brucei brucei infection in mice when used together with nifurtimox. Altogether, EbS and EbS analogues disrupt the trypanothione system, hampering the defense against oxidative stress. Thus, EbS is a promising lead for development of drugs against African trypanosomiasis.
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Affiliation(s)
- Jun Lu
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics
| | | | - Anna-Lena Gustavsson
- Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Tomas N Gustafsson
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics
| | - Birger Sjöberg
- Chemical Biology Consortium Sweden, Science for Life Laboratory, Division of Translational Medicine, Karolinska Institutet, SE-17177 Stockholm, Sweden
| | - Henrik A Johansson
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics; Department of Chemistry-BMC, Uppsala University, SE-751 23 Uppsala, Sweden
| | | | | | - Lars Engman
- Department of Chemistry-BMC, Uppsala University, SE-751 23 Uppsala, Sweden
| | | | - Arne Holmgren
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics.
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34
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Leroux AE, Haanstra JR, Bakker BM, Krauth-Siegel RL. Dissecting the catalytic mechanism of Trypanosoma brucei trypanothione synthetase by kinetic analysis and computational modeling. J Biol Chem 2013; 288:23751-64. [PMID: 23814051 PMCID: PMC3745322 DOI: 10.1074/jbc.m113.483289] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In pathogenic trypanosomes, trypanothione synthetase (TryS) catalyzes the synthesis of both glutathionylspermidine (Gsp) and trypanothione (bis(glutathionyl)spermidine (T(SH)2)). Here we present a thorough kinetic analysis of Trypanosoma brucei TryS in a newly developed phosphate buffer system at pH 7.0 and 37 °C, mimicking the physiological environment of the enzyme in the cytosol of bloodstream parasites. Under these conditions, TryS displays Km values for GSH, ATP, spermidine, and Gsp of 34, 18, 687, and 32 μm, respectively, as well as Ki values for GSH and T(SH)2 of 1 mm and 360 μm, respectively. As Gsp hydrolysis has a Km value of 5.6 mm, the in vivo amidase activity is probably negligible. To obtain deeper insight in the molecular mechanism of TryS, we have formulated alternative kinetic models, with elementary reaction steps represented by linear kinetic equations. The model parameters were fitted to the extensive matrix of steady-state data obtained for different substrate/product combinations under the in vivo-like conditions. The best model describes the full kinetic profile and is able to predict time course data that were not used for fitting. This system's biology approach to enzyme kinetics led us to conclude that (i) TryS follows a ter-reactant mechanism, (ii) the intermediate Gsp dissociates from the enzyme between the two catalytic steps, and (iii) T(SH)2 inhibits the enzyme by remaining bound at its product site and, as does the inhibitory GSH, by binding to the activated enzyme complex. The newly detected concerted substrate and product inhibition suggests that TryS activity is tightly regulated.
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Affiliation(s)
- Alejandro E Leroux
- Biochemie-Zentrum der Universität Heidelberg, D-69120 Heidelberg, Germany
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35
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Trypanothione: A unique bis-glutathionyl derivative in trypanosomatids. Biochim Biophys Acta Gen Subj 2013; 1830:3199-216. [DOI: 10.1016/j.bbagen.2013.01.013] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 01/11/2013] [Accepted: 01/16/2013] [Indexed: 11/21/2022]
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36
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Deponte M. Glutathione catalysis and the reaction mechanisms of glutathione-dependent enzymes. Biochim Biophys Acta Gen Subj 2013; 1830:3217-66. [DOI: 10.1016/j.bbagen.2012.09.018] [Citation(s) in RCA: 625] [Impact Index Per Article: 56.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 09/25/2012] [Indexed: 12/12/2022]
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Abstract
SIGNIFICANCE Parasitic infections continue to be a major problem for global human health. Vaccines are practically not available and chemotherapy is highly unsatisfactory. One approach toward a novel antiparasitic drug development is to unravel pathways that may be suited as future targets. Parasitic organisms show a remarkable diversity with respect to the nature and functions of their main low-molecular-mass antioxidants and many of them developed pathways that do not have a counterpart in their mammalian hosts. RECENT ADVANCES Work of the last years disclosed the individual antioxidants employed by parasites and their distinct pathways. Entamoeba, Trichomonas, and Giardia directly use cysteine as main low-molecular-mass thiol but have divergent cysteine metabolisms. Malarial parasites rely exclusively on cysteine uptake and generate glutathione (GSH) as main free thiol as do metazoan parasites. Trypanosomes and Leishmania have a unique trypanothione-based thiol metabolism but employ individual mechanisms for their cysteine supply. In addition, some trypanosomatids synthesize ovothiol A and/or ascorbate. Various essential parasite enzymes such as trypanothione synthetase and trypanothione reductase in Trypanosomatids and the Schistosoma thioredoxin GSH reductase are currently intensively explored as drug target molecules. CRITICAL ISSUES Essentiality is a prerequisite but not a sufficient property of an enzyme to become a suited drug target. The availability of an appropriate in vivo screening system and many other factors are equally important. FUTURE DIRECTIONS The current organism-wide RNA-interference and proteome analyses are supposed to reveal many more interesting candidates for future drug development approaches directed against the parasite antioxidant defense systems.
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38
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Fueller F, Jehle B, Putzker K, Lewis JD, Krauth-Siegel RL. High throughput screening against the peroxidase cascade of African trypanosomes identifies antiparasitic compounds that inactivate tryparedoxin. J Biol Chem 2012; 287:8792-802. [PMID: 22275351 DOI: 10.1074/jbc.m111.338285] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In African trypanosomes, the detoxification of broad spectrum hydroperoxides relies on a unique cascade composed of trypanothione (T(SH)(2)), trypanothione reductase, tryparedoxin (Tpx), and nonselenium glutathione peroxidase-type enzymes. All three proteins are essential for Trypanosoma brucei. Here, we subjected the complete system to a high throughput screening approach with nearly 80,000 chemicals. Twelve compounds inhibited the peroxidase system. All but one carried chloroalkyl substituents. The detailed kinetic analysis showed that two compounds weakly inhibited trypanothione reductase, but none of them specifically interacted with the peroxidase. They proved to be time-dependent inhibitors of Tpx-modifying Cys-40, the first cysteine of its active site WCPPC motif. Importantly, gel shift assays verified Tpx as a target in the intact parasites. T(SH)(2), present in the in vitro assays and in the cells in high molar excess, did not interfere with Tpx inactivation. The compounds inhibited the proliferation of bloodstream T. brucei with EC(50) values down to <1 μM and exerted up to 83-fold lower toxicity toward HeLa cells. Irreversible inhibitors are traditionally regarded as unfavorable. However, a large number of antimicrobials and anticancer therapeutics acts covalently with their target protein. The compounds identified here also interacted with recombinant human thioredoxin, a distant relative of Tpx. This finding might even be exploited for thioredoxin-based anticancer drug development approaches reported recently. The fact that the T(SH)(2)/Tpx couple occupies a central position within the trypanosomal thiol metabolism and delivers electrons also for the synthesis of DNA precursors renders the parasite-specific oxidoreductase an attractive drug target molecule.
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Affiliation(s)
- Florian Fueller
- Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
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Castro H, Teixeira F, Romao S, Santos M, Cruz T, Flórido M, Appelberg R, Oliveira P, Ferreira-da-Silva F, Tomás AM. Leishmania mitochondrial peroxiredoxin plays a crucial peroxidase-unrelated role during infection: insight into its novel chaperone activity. PLoS Pathog 2011; 7:e1002325. [PMID: 22046130 PMCID: PMC3203189 DOI: 10.1371/journal.ppat.1002325] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 09/02/2011] [Indexed: 11/24/2022] Open
Abstract
Two-cysteine peroxiredoxins are ubiquitous peroxidases that play various functions in cells. In Leishmania and related trypanosomatids, which lack catalase and selenium-glutathione peroxidases, the discovery of this family of enzymes provided the molecular basis for peroxide removal in these organisms. In this report the functional relevance of one of such enzymes, the mitochondrial 2-Cys peroxiredoxin (mTXNPx), was investigated along the Leishmania infantum life cycle. mTXNPx null mutants (mtxnpx(-)) produced by a gene replacement strategy, while indistinguishable from wild type promastigotes, were found unable to thrive in a murine model of infection. Unexpectedly, however, the avirulent phenotype of mtxnpx(-) was not due to lack of the peroxidase activity of mTXNPx as these behaved like controls when exposed to oxidants added exogenously or generated by macrophages during phagocytosis ex vivo. In line with this, mtxnpx(-) were also avirulent when inoculated into murine hosts unable to mount an effective oxidative phagocyte response (B6.p47(phox-/-) and B6.RAG2(-/-) IFN-γ(-/-) mice). Definitive conclusion that the peroxidase activity of mTXNPx is not required for parasite survival in mice was obtained by showing that a peroxidase-inactive version of this protein was competent in rescuing the non-infective phenotype of mtxnpx(-). A novel function is thus proposed for mTXNPx, that of a molecular chaperone, which may explain the impaired infectivity of the null mutants. This premise is based on the observation that the enzyme is able to suppress the thermal aggregation of citrate synthase in vitro. Also, mtxnpx(-) were more sensitive than controls to a temperature shift from 25°C to 37°C, a phenotype reminiscent of organisms lacking specific chaperone genes. Collectively, the findings reported here change the paradigm which regards all trypanosomatid 2-Cys peroxiredoxins as peroxide-eliminating devices. Moreover, they demonstrate, for the first time, that these 2-Cys peroxiredoxins can be determinant for pathogenicity independently of their peroxidase activity.
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Affiliation(s)
- Helena Castro
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Filipa Teixeira
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Susana Romao
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Mariana Santos
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Tânia Cruz
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Manuela Flórido
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Rui Appelberg
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Pedro Oliveira
- ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | | | - Ana M. Tomás
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
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Diechtierow M, Krauth-Siegel RL. A tryparedoxin-dependent peroxidase protects African trypanosomes from membrane damage. Free Radic Biol Med 2011; 51:856-68. [PMID: 21640819 DOI: 10.1016/j.freeradbiomed.2011.05.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 05/11/2011] [Accepted: 05/11/2011] [Indexed: 01/18/2023]
Abstract
Hydroperoxide detoxification in African trypanosomes is achieved by 2-Cys-peroxiredoxin (TXNPx)- and non-selenium glutathione peroxidase (Px)-type enzymes which both obtain their reducing equivalents from the unique trypanothione/tryparedoxin system. Previous RNA interference approaches revealed that the cytosolic TXNPx and the Px-type enzymes are essential for Trypanosoma brucei. Because of partially overlapping in vitro substrate specificities and subcellular localisation the physiological function of the individual enzymes was not yet clear. As shown here, TXNPx and Px are expressed at comparable levels and in their active reduced state. Px-overexpressing parasites were less sensitive toward linoleic acid hydroperoxide but not hydrogen peroxide. Kinetic studies confirmed that Px-but not TXNPx-reduces lipophilic hydroperoxides including phospholipids with high efficiency. Most interestingly, the severe proliferation defect of Px-depleted bloodstream cells could be rescued by Trolox, but not by hydrophilic antioxidants, in the medium. This allowed us to knock-out the three Px genes individually and thus to distinguish their in vivo role. Deletion of the cytosolic Px I and II resulted in extremely fast membrane peroxidation followed by cell lysis. Cells lacking specifically the mitochondrial Px III showed a transient growth retardation and cardiolipin peroxidation but adapted within 24h to normal proliferation.
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Affiliation(s)
- Michael Diechtierow
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
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41
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Van Assche T, Deschacht M, da Luz RAI, Maes L, Cos P. Leishmania-macrophage interactions: insights into the redox biology. Free Radic Biol Med 2011; 51:337-51. [PMID: 21620959 DOI: 10.1016/j.freeradbiomed.2011.05.011] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 04/24/2011] [Accepted: 05/07/2011] [Indexed: 11/19/2022]
Abstract
Leishmaniasis is a neglected tropical disease that affects about 350 million individuals worldwide. The protozoan parasite has a relatively simple life cycle with two principal stages: the flagellated mobile promastigote living in the gut of the sandfly vector and the intracellular amastigote within phagolysosomal vesicles of the vertebrate host macrophage. This review presents a state-of-the-art overview of the redox biology at the parasite-macrophage interface. Although Leishmania species are susceptible in vitro to exogenous superoxide radical, hydrogen peroxide, nitric oxide, and peroxynitrite, they manage to survive the endogenous oxidative burst during phagocytosis and the subsequent elevated nitric oxide production in the macrophage. The parasite adopts various defense mechanisms to cope with oxidative stress: the lipophosphoglycan membrane decreases superoxide radical production by inhibiting NADPH oxidase assembly and the parasite also protects itself by expressing antioxidant enzymes and proteins. Some of these enzymes could be considered potential drug targets because they are not expressed in mammals. In respect to antileishmanial therapy, the effects of current drugs on parasite-macrophage redox biology and its involvement in the development of drug resistance and treatment failure are presented.
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Affiliation(s)
- Tim Van Assche
- Laboratory of Microbiology Parasitology, and Hygiene, University of Antwerp, B-2020 Antwerp, Belgium
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42
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Roldán A, Comini MA, Crispo M, Krauth-Siegel RL. Lipoamide dehydrogenase is essential for both bloodstream and procyclic Trypanosoma brucei. Mol Microbiol 2011; 81:623-39. [DOI: 10.1111/j.1365-2958.2011.07721.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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43
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Flohé L. The trypanothione system and the opportunities it offers to create drugs for the neglected kinetoplast diseases. Biotechnol Adv 2011; 30:294-301. [PMID: 21620942 DOI: 10.1016/j.biotechadv.2011.05.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Revised: 05/06/2011] [Accepted: 05/09/2011] [Indexed: 12/20/2022]
Abstract
Parasitic trypanosomatids (Kinetoplastida) are the causative agents of devastating and hard-to-treat diseases such as African sleeping sickness, Chagas disease and various forms of Leishmaniasis. Altogether they affect > 30 Million patients, account for half a million fatalities p.a. and cause substantial economical problems in the Third World due to human morbidity and life stock losses. The design of efficacious and safe drugs is expected from inhibition of metabolic pathways that are unique and essential to the parasite and absent in the host. In this respect, the trypanothione system first detected in the insect-pathogenic trypanosomatid Crithidia fasciculata qualified as an attractive drug target area. The existence of the system in pathogenic relatives was established by homology cloning and PCR. The vital importance of the system was verified in Trypanosoma brucei by dsRNA technology or knock-out in other trypanosomatids, respectively, and is explained by its pivotal role in the parasite's antioxidant defense and DNA synthesis. The key system component is the bis-glutathionyl derivative of spermidine, trypanothione. It is the proximal reductant of tryparedoxin which substitutes for thioredoxin-, glutaredoxin- and glutathione-dependent reactions. Heterologous expression, functional characterization and crystallization of recombinant system components finally enable structure-based rational inhibitor design.
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Affiliation(s)
- Leopold Flohé
- Institute of Chemistry, Otto-von-Guericke-Universität, Universitätsplatz 2, D-39106 Magdeburg, Germany.
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König J, Wyllie S, Wells G, Stevens MF, Wyatt PG, Fairlamb AH. Antitumor quinol PMX464 is a cytocidal anti-trypanosomal inhibitor targeting trypanothione metabolism. J Biol Chem 2011; 286:8523-8533. [PMID: 21212280 PMCID: PMC3048735 DOI: 10.1074/jbc.m110.214833] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Better drugs are urgently needed for the treatment of African sleeping sickness. We tested a series of promising anticancer agents belonging to the 4-substituted 4-hydroxycyclohexa-2,5-dienones class (“quinols”) and identified several with potent trypanocidal activity (EC50 < 100 nm). In mammalian cells, quinols are proposed to inhibit the thioredoxin/thioredoxin reductase system, which is absent from trypanosomes. Studies with the prototypical 4-benzothiazole-substituted quinol, PMX464, established that PMX464 is rapidly cytocidal, similar to the arsenical drug, melarsen oxide. Cell lysis by PMX464 was accelerated by addition of sublethal concentrations of glucose oxidase implicating oxidant defenses in the mechanism of action. Whole cells treated with PMX464 showed a loss of trypanothione (T(SH)2), a unique dithiol in trypanosomes, and tryparedoxin peroxidase (TryP), a 2-Cys peroxiredoxin similar to mammalian thioredoxin peroxidase. Enzyme assays revealed that T(SH)2, TryP, and a glutathione peroxidase-like tryparedoxin-dependent peroxidase were inhibited in time- and concentration-dependent manners. The inhibitory activities of various quinol analogues against these targets showed a good correlation with growth inhibition of Trypanosoma brucei. The monothiols glutathione and l-cysteine bound in a 2:1 ratio with PMX464 with Kd values of 6 and 27 μm, respectively, whereas T(SH)2 bound more tightly in a 1:1 ratio with a Kd value of 430 nm. Overexpression of trypanothione synthetase in T. brucei decreased sensitivity to PMX464 indicating that the key metabolite T(SH)2 is a target for quinols. Thus, the quinol pharmacophore represents a novel lead structure for the development of a new drug against African sleeping sickness.
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Affiliation(s)
- Janine König
- From the Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH and
| | - Susan Wyllie
- From the Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH and
| | - Geoffrey Wells
- the Centre for Biomolecular Sciences, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Malcolm F Stevens
- the Centre for Biomolecular Sciences, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Paul G Wyatt
- From the Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH and
| | - Alan H Fairlamb
- From the Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH and.
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Mitochondrial redox metabolism in trypanosomatids is independent of tryparedoxin activity. PLoS One 2010; 5:e12607. [PMID: 20838623 PMCID: PMC2935891 DOI: 10.1371/journal.pone.0012607] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Accepted: 08/13/2010] [Indexed: 01/07/2023] Open
Abstract
Tryparedoxins (TXNs) are oxidoreductases unique to trypanosomatids (including Leishmania and Trypanosoma parasites) that transfer reducing equivalents from trypanothione, the major thiol in these organisms, to sulfur-dependent peroxidases and other dithiol proteins. The existence of a TXN within the mitochondrion of trypanosomatids, capable of driving crucial redox pathways, is considered a requisite for normal parasite metabolism. Here this concept is shown not to apply to Leishmania. First, removal of the Leishmania infantum mitochondrial TXN (LiTXN2) by gene-targeting, had no significant effect on parasite survival, even in the context of an animal infection. Second, evidence is presented that no other TXN is capable of replacing LiTXN2. In fact, although a candidate substitute for LiTXN2 (LiTXN3) was found in the genome of L. infantum, this was shown in biochemical assays to be poorly reduced by trypanothione and to be unable to reduce sulfur-containing peroxidases. Definitive conclusion that LiTXN3 cannot directly reduce proteins located within inner mitochondrial compartments was provided by analysis of its subcellular localization and membrane topology, which revealed that LiTXN3 is a tail-anchored (TA) mitochondrial outer membrane protein presenting, as characteristic of TA proteins, its N-terminal end (containing the redox-active domain) exposed to the cytosol. This manuscript further proposes the separation of trypanosomatid TXN sequences into two classes and this is supported by phylogenetic analysis: i) class I, encoding active TXNs, and ii) class II, coding for TA proteins unlikely to function as TXNs. Trypanosoma possess only two TXNs, one belonging to class I (which is cytosolic) and the other to class II. Thus, as demonstrated for Leishmania, the mitochondrial redox metabolism in Trypanosoma may also be independent of TXN activity. The major implication of these findings is that mitochondrial functions previously thought to depend on the provision of electrons by a TXN enzyme must proceed differently.
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Sienkiewicz N, Ong HB, Fairlamb AH. Trypanosoma brucei pteridine reductase 1 is essential for survival in vitro and for virulence in mice. Mol Microbiol 2010; 77:658-71. [PMID: 20545846 PMCID: PMC2916222 DOI: 10.1111/j.1365-2958.2010.07236.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gene knockout and knockdown methods were used to examine essentiality of pteridine reductase (PTR1) in pterin metabolism in the African trypanosome. Attempts to generate PTR1 null mutants in bloodstream form Trypanosoma brucei proved unsuccessful; despite integration of drug selectable markers at the target locus, the gene for PTR1 was either retained at the same locus or elsewhere in the genome. However, RNA interference (RNAi) resulted in complete knockdown of endogenous protein after 48 h, followed by cell death after 4 days. This lethal phenotype was reversed by expression of enzymatically active Leishmania major PTR1 in RNAi lines ((oe)RNAi) or by addition of tetrahydrobiopterin to cultures. Loss of PTR1 was associated with gross morphological changes due to a defect in cytokinesis, resulting in cells with multiple nuclei and kinetoplasts, as well as multiple detached flagella. Electron microscopy also revealed increased numbers of glycosomes, while immunofluorescence microscopy showed increased and more diffuse staining for glycosomal matrix enzymes, indicative of mis-localisation to the cytosol. Mis-localisation was confirmed by digitonin fractionation experiments. RNAi cell lines were markedly less virulent than wild-type parasites in mice and virulence was restored in the (oe)RNAi line. Thus, PTR1 may be a drug target for human African trypanosomiasis.
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Affiliation(s)
- Natasha Sienkiewicz
- Division of Biological Chemistry & Drug Discovery, College of Life Sciences, University of Dundee, Dundee, UK
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Marquez VE, Arias DG, Piattoni CV, Robello C, Iglesias AA, Guerrero SA. Cloning, expression, and characterization of a dithiol glutaredoxin from Trypanosoma cruzi. Antioxid Redox Signal 2010; 12:787-92. [PMID: 19769456 DOI: 10.1089/ars.2009.2907] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Glutaredoxins play an important role in cellular functionality. A putative dithiol glutaredoxin is encoded in the genome of Trypanosoma cruzi. We cloned the gene and obtained the recombinant protein, which behaved as a typical thioltransferase. Activity was variable and dependent on the nature of reducer or oxidant agent used, or both. Epimastigote extracts exhibited similar activity, suggesting the occurrence of the protein in the parasite. Results support a redox scenario in T. cruzi, with glutaredoxin being involved mainly in reduction of glutathione disulfide as well as in deglutathionylation of target proteins.
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Affiliation(s)
- Vanina E Marquez
- Instituto de Agrobiotecnología del Litoral, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral., Ciudad Universitaria-Paraje El Pozo, S3000ZAA Santa Fe, Argentina
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Structural insights into the catalytic mechanism of Trypanosoma cruzi GPXI (glutathione peroxidase-like enzyme I). Biochem J 2010; 425:513-22. [DOI: 10.1042/bj20091167] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Current drug therapies against Trypanosoma cruzi, the causative agent of Chagas disease, have limited effectiveness and are highly toxic. T. cruzi-specific metabolic pathways that utilize trypanothione for the reduction of peroxides are being explored as potential novel therapeutic targets. In the present study we solved the X-ray crystal structure of one of the T. cruzi enzymes involved in peroxide reduction, the glutathione peroxidase-like enzyme TcGPXI (T. cruzi glutathione peroxidase-like enzyme I). We also characterized the wild-type, C48G and C96G variants of TcGPXI by NMR spectroscopy and biochemical assays. Our results show that residues Cys48 and Cys96 are required for catalytic activity. In solution, the TcGPXI molecule readily forms a Cys48–Cys96 disulfide bridge and the polypeptide segment containing Cys96 lacks regular secondary structure. NMR spectra of the reduced TcGPXI are indicative of a protein that undergoes widespread conformational exchange on an intermediate time scale. Despite the absence of the disulfide bond, the active site mutant proteins acquired an oxidized-like conformation as judged from their NMR spectra. The protein that was used for crystallization was pre-oxidized by t-butyl hydroperoxide; however, the electron density maps clearly showed that the active site cysteine residues are in the reduced thiol form, indicative of X-ray-induced reduction. Our crystallographic and solution studies suggest a level of structural plasticity in TcGPXI consistent with the requirement of the atypical two-cysteine (2-Cys) peroxiredoxin-like mechanism implied by the behaviour of the Cys48 and Cys96 mutant proteins.
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Mukherjee A, Roy G, Guimond C, Ouellette M. The γ-glutamylcysteine synthetase gene of Leishmania is essential and involved in response to oxidants. Mol Microbiol 2009; 74:914-27. [DOI: 10.1111/j.1365-2958.2009.06907.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wendler A, Irsch T, Rabbani N, Thornalley PJ, Krauth-Siegel RL. Glyoxalase II does not support methylglyoxal detoxification but serves as a general trypanothione thioesterase in African trypanosomes. Mol Biochem Parasitol 2009; 163:19-27. [DOI: 10.1016/j.molbiopara.2008.09.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 09/10/2008] [Accepted: 09/12/2008] [Indexed: 10/21/2022]
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