1
|
Guevara-Flores A, Nava-Balderas G, de Jesús Martínez-González J, Vásquez-Lima C, Rendón JL, del Arenal Mena IP. A Physiological Approach to Explore How Thioredoxin-Glutathione Reductase (TGR) and Peroxiredoxin (Prx) Eliminate H 2O 2 in Cysticerci of Taenia. Antioxidants (Basel) 2024; 13:444. [PMID: 38671892 PMCID: PMC11047392 DOI: 10.3390/antiox13040444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 04/28/2024] Open
Abstract
Peroxiredoxins (Prxs) and glutathione peroxidases (GPxs) are the main enzymes of the thiol-dependent antioxidant systems responsible for reducing the H2O2 produced via aerobic metabolism or parasitic organisms by the host organism. These antioxidant systems maintain a proper redox state in cells. The cysticerci of Taenia crassiceps tolerate millimolar concentrations of this oxidant. To understand the role played by Prxs in this cestode, two genes for Prxs, identified in the genome of Taenia solium (TsPrx1 and TsPrx3), were cloned. The sequence of the proteins suggests that both isoforms belong to the class of typical Prxs 2-Cys. In addition, TsPrx3 harbors a mitochondrial localization signal peptide and two motifs (-GGLG- and -YP-) associated with overoxidation. Our kinetic characterization assigns them as thioredoxin peroxidases (TPxs). While TsPrx1 and TsPrx3 exhibit the same catalytic efficiency, thioredoxin-glutathione reductase from T. crassiceps (TcTGR) was five and eight times higher. Additionally, the latter demonstrated a lower affinity (>30-fold) for H2O2 in comparison with TsPrx1 and TsPrx3. The TcTGR contains a Sec residue in its C-terminal, which confers additional peroxidase activity. The aforementioned aspect implies that TsPrx1 and TsPrx3 are catalytically active at low H2O2 concentrations, and the TcTGR acts at high H2O2 concentrations. These results may explain why the T. crassiceps cysticerci can tolerate high H2O2 concentrations.
Collapse
Affiliation(s)
- Alberto Guevara-Flores
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70-159, Mexico City 04510, Mexico; (A.G.-F.); (J.d.J.M.-G.); (C.V.-L.); (J.L.R.)
| | - Gabriela Nava-Balderas
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70-159, Mexico City 04510, Mexico
| | - José de Jesús Martínez-González
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70-159, Mexico City 04510, Mexico; (A.G.-F.); (J.d.J.M.-G.); (C.V.-L.); (J.L.R.)
| | - César Vásquez-Lima
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70-159, Mexico City 04510, Mexico; (A.G.-F.); (J.d.J.M.-G.); (C.V.-L.); (J.L.R.)
| | - Juan Luis Rendón
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70-159, Mexico City 04510, Mexico; (A.G.-F.); (J.d.J.M.-G.); (C.V.-L.); (J.L.R.)
| | - Irene Patricia del Arenal Mena
- Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70-159, Mexico City 04510, Mexico; (A.G.-F.); (J.d.J.M.-G.); (C.V.-L.); (J.L.R.)
| |
Collapse
|
2
|
Imran A, Ghosh A. Evolutionary expansion, functional diversification, and transcript profiling of plant Glutathione Peroxidases. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 341:111991. [PMID: 38266716 DOI: 10.1016/j.plantsci.2024.111991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/11/2023] [Accepted: 01/12/2024] [Indexed: 01/26/2024]
Abstract
Glutathione peroxidases (GPXs) play a crucial role in combating activated oxygen species and have been widely studied for their involvement in stress responses. In addition to their stress-related functions, GPXs exhibit diverse roles such as immunological response, and involvement in growth and development. These enzymes are found in both animals and plants, with multiple families identified in the evolutionarily diverse species. These families consist of conserved genes as well as unique members, highlighting the evolutionary diversification of GPX members. While animals have eight GPX families, plants possess five families. Notably, plant genomes undergo duplication and expansion events, leading to an increase in the number of GPX genes and the overall size of the GPX superfamily. This expansion suggests a wide range of functional roles for GPX. In this study, the evolutionary diversification, family expansion, and diverse functional roles of GPX enzymes have been investigated. Additionally, the expression profile of Arabidopsis and Oryza sativa GPX genes were analyzed in different developmental stages, tissues, and abiotic stress conditions. Further extensive research has been required to unravel the intricate interplay between GPX and other proteins, to gain the comprehensive mechanism governing the physiological and developmental roles of GPX.
Collapse
Affiliation(s)
- Al Imran
- Department of Biochemistry and Molecular Biology, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh
| | - Ajit Ghosh
- Department of Biochemistry and Molecular Biology, Shahjalal University of Science and Technology, Sylhet 3114, Bangladesh.
| |
Collapse
|
3
|
Flohé L. Looking Back at the Early Stages of Redox Biology. Antioxidants (Basel) 2020; 9:E1254. [PMID: 33317108 PMCID: PMC7763103 DOI: 10.3390/antiox9121254] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 11/12/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
The beginnings of redox biology are recalled with special emphasis on formation, metabolism and function of reactive oxygen and nitrogen species in mammalian systems. The review covers the early history of heme peroxidases and the metabolism of hydrogen peroxide, the discovery of selenium as integral part of glutathione peroxidases, which expanded the scope of the field to other hydroperoxides including lipid hydroperoxides, the discovery of superoxide dismutases and superoxide radicals in biological systems and their role in host defense, tissue damage, metabolic regulation and signaling, the identification of the endothelial-derived relaxing factor as the nitrogen monoxide radical (more commonly named nitric oxide) and its physiological and pathological implications. The article highlights the perception of hydrogen peroxide and other hydroperoxides as signaling molecules, which marks the beginning of the flourishing fields of redox regulation and redox signaling. Final comments describe the development of the redox language. In the 18th and 19th century, it was highly individualized and hard to translate into modern terminology. In the 20th century, the redox language co-developed with the chemical terminology and became clearer. More recently, the introduction and inflationary use of poorly defined terms has unfortunately impaired the understanding of redox events in biological systems.
Collapse
Affiliation(s)
- Leopold Flohé
- Dipartimento di Medicina Molecolare, Università degli Studi di Padova, v.le G. Colombo 3, 35121 Padova, Italy;
- Departamento de Bioquímica, Universidad de la República, Avda. General Flores 2125, 11800 Montevideo, Uruguay
| |
Collapse
|
4
|
Structural and functional characterization of the glutathione peroxidase-like thioredoxin peroxidase from the fungus Trichoderma reesei. Int J Biol Macromol 2020; 167:93-100. [PMID: 33259843 DOI: 10.1016/j.ijbiomac.2020.11.179] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/13/2020] [Accepted: 11/25/2020] [Indexed: 11/22/2022]
Abstract
Glutathione peroxidases (GPx) are a family of enzymes with the ability to reduce organic and inorganic hydroperoxides to the corresponding alcohols using glutathione or thioredoxin as an electron donor. Here, we report the functional and structural characterization of a GPx identified in Trichoderma reesei (TrGPx). TrGPx was recombinantly expressed in a bacterial host and purified using affinity. Using a thioredoxin coupled assay, TrGPx exhibited activity of 28 U and 12.5 U in the presence of the substrates H2O2 and t-BOOH, respectively, and no activity was observed when glutathione was used. These results indicated that TrGPx is a thioredoxin peroxidase and hydrolyses H2O2 better than t-BOOH. TrGPx kinetic parameters using a pyrogallol assay resulted at Kmapp = 11.7 mM, Vmaxapp = 10.9 IU/μg TrGPx, kcat = 19 s-1 and a catalytic efficiency of 1.6 mM-1 s-1 to H2O2 as substrate. Besides that, TrGPx demonstrated an optimum pH ranging from 9.0-12.0 and a half-life of 36 min at 80 °C. TrGPx 3D-structure was obtained in a reduced state and non-catalytic conformation. The overall fold is similar to the other phospholipid-hydroperoxide glutathione peroxidases. These data contribute to understand the antioxidant mechanism in fungi and provide information for using antioxidant enzymes in biotechnological applications.
Collapse
|
5
|
Cubas-Gaona LL, de Francisco P, Martín-González A, Gutiérrez JC. Tetrahymena Glutathione Peroxidase Family: A Comparative Analysis of These Antioxidant Enzymes and Differential Gene Expression to Metals and Oxidizing Agents. Microorganisms 2020; 8:microorganisms8071008. [PMID: 32635666 PMCID: PMC7409322 DOI: 10.3390/microorganisms8071008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/21/2020] [Accepted: 07/02/2020] [Indexed: 12/26/2022] Open
Abstract
In the present work, an extensive analysis of the putative glutathione peroxidases (GPx) of the eukaryotic microorganism model Tetrahymena thermophila is carried out. A comparative analysis with GPx present in other Tetrahymena species and other very taxonomically diverse ciliates is also performed. A majority of ciliate GPx have replaced the selenocysteine (Sec) by Cys in its catalytic center, so they can be considered as phospholipid hydroperoxide glutathione peroxidases (PHGPx). Selenocysteine insertion sequence (SECIS) elements have been detected in several ciliate GPx that do not incorporate Sec in their amino acid sequences, and conversely, in other ciliate GPx with Sec, no SECIS elements are detected. These anomalies are analyzed and discussed. From the phylogenetic analysis using the ciliate GPx amino acid sequences, the existence of extensive intra- and interspecific gene duplications that produced multiple GPx isoforms in each species is inferred. The ancestral character of the selenoproteins is also corroborated. The analysis by qRT-PCR of six selected T. thermophila GPx genes has shown a quantitative differential expression between them, depending on the stressor (oxidizing agents, apoptotic inducer or metals) and the time of exposure.
Collapse
Affiliation(s)
| | - Patricia de Francisco
- Department of Molecular Evolution, Centro de Astrobiología (CSIC-INTA), Carretera de Ajalvir km 4, Torrejón de Ardoz, 28850 Madrid, Spain;
| | - Ana Martín-González
- Departamento de Genética, Fisiología y Microbiología, Facultad de Biología. C/. José Antonio Nováis, 12. Universidad Complutense (UCM), 28040 Madrid, Spain;
| | - Juan Carlos Gutiérrez
- Departamento de Genética, Fisiología y Microbiología, Facultad de Biología. C/. José Antonio Nováis, 12. Universidad Complutense (UCM), 28040 Madrid, Spain;
- Correspondence:
| |
Collapse
|
6
|
Lienkamp AC, Heine T, Tischler D. Glutathione: A powerful but rare cofactor among Actinobacteria. ADVANCES IN APPLIED MICROBIOLOGY 2020; 110:181-217. [PMID: 32386605 DOI: 10.1016/bs.aambs.2019.12.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Glutathione (γ-l-glutamyl-l-cysteinylglycine, GSH) is a powerful cellular redox agent. In nature only the l,l-form is common among the tree of life. It serves as antioxidant or redox buffer system, protein regeneration and activation by interaction with thiol groups, unspecific reagent for conjugation during detoxification, marker for amino acid or peptide transport even through membranes, activation or solubilization of compounds during degradative pathways or just as redox shuttle. However, the role of GSH production and utilization in bacteria is more complex and especially little is known for the Actinobacteria. Some recent reports on GSH use in degradative pathways came across and this is described herein. GSH is used by transferases to activate and solubilize epoxides. It allows funneling epoxides as isoprene oxide or styrene oxide into central metabolism. Thus, the distribution of GSH synthesis, recycling and application among bacteria and especially Actinobacteria are highlighted including the pathways and contributing enzymes.
Collapse
Affiliation(s)
- Anna C Lienkamp
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Thomas Heine
- Environmental Microbiology, Faculty of Chemistry and Physics, TU Bergakademie Freiberg, Freiberg, Germany
| | - Dirk Tischler
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany.
| |
Collapse
|
7
|
Al-Asadi S, Malik A, Bakiu R, Santovito G, Menz I, Schuller K. Characterization of the peroxiredoxin 1 subfamily from Tetrahymena thermophila. Cell Mol Life Sci 2019; 76:4745-4768. [PMID: 31129858 PMCID: PMC11105310 DOI: 10.1007/s00018-019-03131-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/02/2019] [Accepted: 05/02/2019] [Indexed: 12/16/2022]
Abstract
Peroxiredoxins are antioxidant enzymes that use redox active Cys residues to reduce H2O2 and various organic hydroperoxides to less reactive products, and thereby protect cells against oxidative stress. In yeasts and mammals, the Prx1 proteins are sensitive to hyperoxidation and consequent loss of their peroxidase activity whereas in most bacteria they are not. In this paper we report the characterization of the Prx1 family in the non-parasitic protist Tetrahymena thermophila. In this organism, four genes potentially encoding Prx1 have been identified. In particular, we show that the mitochondrial Prx1 protein (Prx1m) from T. thermophila is relatively robust to hyperoxidation. This is surprising given that T. thermophila is a eukaryote like yeasts and mammals. In addition, the proliferation of the T. thermophila cells was relatively robust to inhibition by H2O2, cumene hydroperoxide and plant natural products that are known to promote the production of H2O2. In the presence of these agents, the abundance of the T. thermophila Prx1m protein was shown to increase. This suggested that the Prx1m protein may be protecting the cells against oxidative stress. There was no evidence for any increase in Prx1m gene expression in the stressed cells. Thus, increasing protein stability rather than increasing gene expression may explain the increasing Prx1m protein abundance we observed.
Collapse
Affiliation(s)
- Sarmad Al-Asadi
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia
- Department of Biology, College of Education for Pure Sciences, University of Basrah, Basrah, Iraq
| | - Arif Malik
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia
| | - Rigers Bakiu
- Department of Aquaculture and Fisheries, Agricultural University of Tirana, Tirana, Albania
| | | | - Ian Menz
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia
| | - Kathryn Schuller
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia.
| |
Collapse
|
8
|
Vučković A, Bosello Travain V, Bordin L, Cozza G, Miotto G, Rossetto M, Toppo S, Venerando R, Zaccarin M, Maiorino M, Ursini F, Roveri A. Inactivation of the glutathione peroxidase GPx4 by the ferroptosis‐inducing molecule RSL3 requires the adaptor protein 14‐3‐3ε. FEBS Lett 2019; 594:611-624. [DOI: 10.1002/1873-3468.13631] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/12/2019] [Accepted: 09/26/2019] [Indexed: 01/17/2023]
Affiliation(s)
| | | | - Luciana Bordin
- Department of Molecular Medicine University of Padova Italy
| | - Giorgio Cozza
- Department of Molecular Medicine University of Padova Italy
| | | | | | - Stefano Toppo
- Department of Molecular Medicine University of Padova Italy
| | - Rina Venerando
- Department of Molecular Medicine University of Padova Italy
| | | | | | - Fulvio Ursini
- Department of Molecular Medicine University of Padova Italy
| | | |
Collapse
|
9
|
The interactome of 2-Cys peroxiredoxins in Plasmodium falciparum. Sci Rep 2019; 9:13542. [PMID: 31537845 PMCID: PMC6753162 DOI: 10.1038/s41598-019-49841-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 08/12/2019] [Indexed: 12/11/2022] Open
Abstract
AbstractPeroxiredoxins (Prxs) are crucially involved in maintaining intracellular H2O2homeostasis via their peroxidase activity. However, more recently, this class of proteins was found to also transmit oxidizing equivalents to selected downstream proteins, which suggests an important function of Prxs in the regulation of cellular protein redox relays. Using a pull-down assay based on mixed disulfide fishing, we characterized the thiol-dependent interactome of cytosolic Prx1a and mitochondrial Prx1m from the apicomplexan malaria parasitePlasmodium falciparum(Pf). Here, 127 cytosolic and 20 mitochondrial proteins that are components of essential cellular processes were found to interact withPfPrx1a andPfPrx1m, respectively. Notably, our data obtained with active-site mutants suggests that reducing equivalents might also be transferred from Prxs to target proteins. Initial functional analyses indicated that the interaction with Prx can strongly impact the activity of target proteins. The results provide initial insights into the interactome of Prxs at the level of a eukaryotic whole cell proteome. Furthermore, they contribute to our understanding of redox regulatory principles and thiol-dependent redox relays of Prxs in subcellular compartments.
Collapse
|
10
|
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: 53] [Impact Index Per Article: 10.6] [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.
Collapse
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
| | | |
Collapse
|
11
|
Kooistra RL, David R, Ruiz AC, Powers SW, Haselton KJ, Kiernan K, Blagborough AM, Solamen L, Olsen KW, Putonti C, Kanzok SM. Characterization of a protozoan Phosducin-like protein-3 (PhLP-3) reveals conserved redox activity. PLoS One 2019; 13:e0209699. [PMID: 30596727 PMCID: PMC6312279 DOI: 10.1371/journal.pone.0209699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 12/09/2018] [Indexed: 11/18/2022] Open
Abstract
We recently identified three novel thioredoxin-like genes in the genome of the protozoan parasite Plasmodium that belong to the Phosducin-like family of proteins (PhLP). PhLPs are small cytosolic proteins hypothesized to function in G-protein signaling and protein folding. Although PhLPs are highly conserved in eukaryotes from yeast to mammals, only a few representatives have been experimentally characterized to date. In addition, while PhLPs contain a thioredoxin domain, they lack a CXXC motif, a strong indicator for redox activity, and it is unclear whether members of the PhLP family are enzymatically active. Here, we describe PbPhLP-3 as the first phosducin-like protein of a protozoan organism, Plasmodium berghei. Initial transcription analysis revealed continuous low-level expression of pbphlp-3 throughout the complex Plasmodium life cycle. Attempts to knockout pbphlp-3 in P. berghei did not yield live parasites, suggesting an essential role for the gene in Plasmodium. We cloned, expressed and purified PbPhLP-3 and determined that the recombinant protein is redox active in vitro in a thioredoxin-coupled redox assay. It also has the capacity to reduce the organic compound tert-Butyl hydroperoxide (TBHP) in vitro, albeit at low efficiency. Sequence analysis, structural modeling, and site-directed mutagenesis revealed a conserved cysteine in the thioredoxin domain to be the redox active residue. Lastly, we provide evidence that recombinant human PhLP-3 exhibits redox activity similar to that of PbPhLP-3 and suggest that redox activity may be conserved in PhLP-3 homologs of other species. Our data provide new insight into the function of PhLP-3, which is hypothesized to act as co-chaperones in the folding and regulation of cytoskeletal proteins. We discuss the potential implications of PhLP-3 as a thioredoxin-target protein and possible links between the cellular redox network and the eukaryotic protein folding machinery.
Collapse
Affiliation(s)
- Rachel L. Kooistra
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
| | - Robin David
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
| | - Ana C. Ruiz
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
| | - Sean W. Powers
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
| | - Kyle J. Haselton
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
| | - Kaitlyn Kiernan
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
| | - Andrew M. Blagborough
- Department of Life Sciences, Imperial College London, South Kensington Campus, London, United Kingdom
| | - Ligin Solamen
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
- Bioinformatics Program, Loyola University Chicago, Chicago, IL, United States of America
| | - Kenneth W. Olsen
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, IL, United States of America
| | - Catherine Putonti
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
- Bioinformatics Program, Loyola University Chicago, Chicago, IL, United States of America
- Department of Computer Science, Loyola University Chicago, Chicago, IL, United States of America
| | - Stefan M. Kanzok
- Department of Biology, Loyola University Chicago, Chicago, IL, United States of America
- Bioinformatics Program, Loyola University Chicago, Chicago, IL, United States of America
- * E-mail:
| |
Collapse
|
12
|
Reyes AM, Pedre B, De Armas MI, Tossounian MA, Radi R, Messens J, Trujillo M. Chemistry and Redox Biology of Mycothiol. Antioxid Redox Signal 2018; 28:487-504. [PMID: 28372502 DOI: 10.1089/ars.2017.7074] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
SIGNIFICANCE Mycothiol (MSH, AcCys-GlcN-Ins) is the main low-molecular weight (LMW) thiol of most Actinomycetes, including the human pathogen Mycobacterium tuberculosis that affects millions of people worldwide. Strains with decreased MSH content show increased susceptibilities to hydroperoxides and electrophilic compounds. In M. tuberculosis, MSH modulates the response to several antituberculosis drugs. Enzymatic routes involving MSH could provide clues for specific drug design. Recent Advances: Physicochemical data argue against a rapid, nonenzymatic reaction of MSH with oxidants, disulfides, or electrophiles. Moreover, exposure of the bacteria to high concentrations of two-electron oxidants resulted in protein mycothiolation. The recently described glutaredoxin-like protein mycoredoxin-1 (Mrx-1) provides a route for catalytic reduction of mycothiolated proteins, protecting critical cysteines from irreversible oxidation. The description of MSH/Mrx-1-dependent activities of peroxidases helped to explain the higher susceptibility to oxidants observed in Actinomycetes lacking MSH. Moreover, the first mycothiol-S-transferase, member of the DinB superfamily of proteins, was described. In Corynebacterium, both the MSH/Mrx-1 and the thioredoxin pathways reduce methionine sulfoxide reductase A. A novel tool for in vivo imaging of the MSH/mycothiol disulfide (MSSM) status allows following changes in the mycothiol redox state during macrophage infection and its relationship with antibiotic sensitivity. CRITICAL ISSUES Redundancy of MSH with other LMW thiols is starting to be unraveled and could help to rationalize the differences in the reported importance of MSH synthesis observed in vitro versus in animal infection models. FUTURE DIRECTIONS Future work should be directed to establish the structural bases of the specificity of MSH-dependent enzymes, thus facilitating drug developments. Antioxid. Redox Signal. 28, 487-504.
Collapse
Affiliation(s)
- Aníbal M Reyes
- 1 Departamento de Bioquímica, Facultad de Medicina, Universidad de la República , Montevideo, Uruguay .,2 Center for Free Radical and Biomedical Research , Universidad de la República, Montevideo, Uruguay
| | - Brandán Pedre
- 3 Center for Structural Biology , VIB, Brussels, Belgium .,4 Brussels Center for Redox Biology , Brussels, Belgium .,5 Structural Biology Brussels, Vrije Universiteit Brussel , Brussels, Belgium
| | - María Inés De Armas
- 1 Departamento de Bioquímica, Facultad de Medicina, Universidad de la República , Montevideo, Uruguay .,2 Center for Free Radical and Biomedical Research , Universidad de la República, Montevideo, Uruguay
| | - Maria-Armineh Tossounian
- 3 Center for Structural Biology , VIB, Brussels, Belgium .,4 Brussels Center for Redox Biology , Brussels, Belgium .,5 Structural Biology Brussels, Vrije Universiteit Brussel , Brussels, Belgium
| | - Rafael Radi
- 1 Departamento de Bioquímica, Facultad de Medicina, Universidad de la República , Montevideo, Uruguay .,2 Center for Free Radical and Biomedical Research , Universidad de la República, Montevideo, Uruguay
| | - Joris Messens
- 3 Center for Structural Biology , VIB, Brussels, Belgium .,4 Brussels Center for Redox Biology , Brussels, Belgium .,5 Structural Biology Brussels, Vrije Universiteit Brussel , Brussels, Belgium
| | - Madia Trujillo
- 1 Departamento de Bioquímica, Facultad de Medicina, Universidad de la República , Montevideo, Uruguay .,2 Center for Free Radical and Biomedical Research , Universidad de la República, Montevideo, Uruguay
| |
Collapse
|
13
|
The Architecture of Thiol Antioxidant Systems among Invertebrate Parasites. Molecules 2017; 22:molecules22020259. [PMID: 28208651 PMCID: PMC6155587 DOI: 10.3390/molecules22020259] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 02/03/2017] [Indexed: 01/14/2023] Open
Abstract
The use of oxygen as the final electron acceptor in aerobic organisms results in an improvement in the energy metabolism. However, as a byproduct of the aerobic metabolism, reactive oxygen species are produced, leaving to the potential risk of an oxidative stress. To contend with such harmful compounds, living organisms have evolved antioxidant strategies. In this sense, the thiol-dependent antioxidant defense systems play a central role. In all cases, cysteine constitutes the major building block on which such systems are constructed, being present in redox substrates such as glutathione, thioredoxin, and trypanothione, as well as at the catalytic site of a variety of reductases and peroxidases. In some cases, the related selenocysteine was incorporated at selected proteins. In invertebrate parasites, antioxidant systems have evolved in a diversity of both substrates and enzymes, representing a potential area in the design of anti-parasite strategies. The present review focus on the organization of the thiol-based antioxidant systems in invertebrate parasites. Differences between these taxa and its final mammal host is stressed. An understanding of the antioxidant defense mechanisms in this kind of parasites, as well as their interactions with the specific host is crucial in the design of drugs targeting these organisms.
Collapse
|
14
|
A disrupted transsulphuration pathway results in accumulation of redox metabolites and induction of gametocytogenesis in malaria. Sci Rep 2017; 7:40213. [PMID: 28091526 PMCID: PMC5238400 DOI: 10.1038/srep40213] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 12/05/2016] [Indexed: 12/11/2022] Open
Abstract
Intra-erythrocytic growth of malaria parasite is known to induce redox stress. In addition to haem degradation which generates reactive oxygen species (ROS), the parasite is also thought to efflux redox active homocysteine. To understand the basis underlying accumulation of homocysteine, we have examined the transsulphuration (TS) pathway in the parasite, which is known to convert homocysteine to cysteine in higher eukaryotes. Our bioinformatic analysis revealed absence of key enzymes in the biosynthesis of cysteine namely cystathionine-β-synthase and cystathionine-γ-lyase in the parasite. Using mass spectrometry, we confirmed the absence of cystathionine, which is formed by enzymatic conversion of homocysteine thereby confirming truncation of TS pathway. We also quantitated levels of glutathione and homocysteine in infected erythrocytes and its spent medium. Our results showed increase in levels of these metabolites intracellularly and in culture supernatants. Our results provide a mechanistic basis for the long-known occurrence of hyperhomocysteinemia in malaria. Most importantly we find that homocysteine induces the transcription factor implicated in gametocytogenesis namely AP2-G and consequently triggers sexual stage conversion. We confirmed this observation both in vitro using Plasmodium falciparum cultures, and in vivo in the mouse model of malaria. Our study implicates homocysteine as a potential physiological trigger of gametocytogenesis.
Collapse
|
15
|
Dennison NJ, Saraiva RG, Cirimotich CM, Mlambo G, Mongodin EF, Dimopoulos G. Functional genomic analyses of Enterobacter, Anopheles and Plasmodium reciprocal interactions that impact vector competence. Malar J 2016; 15:425. [PMID: 27549662 PMCID: PMC4994321 DOI: 10.1186/s12936-016-1468-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 08/02/2016] [Indexed: 11/23/2022] Open
Abstract
Background Malaria exerts a tremendous socioeconomic impact worldwide despite current control efforts, and novel disease transmission-blocking strategies are urgently needed. The Enterobacter bacterium Esp_Z, which is naturally harboured in the mosquito midgut, can inhibit the development of Plasmodium parasites prior to their invasion of the midgut epithelium through a mechanism that involves oxidative stress. Here, a multifaceted approach is used to study the tripartite interactions between the mosquito, Esp_Z and Plasmodium, towards addressing the feasibility of using sugar-baited exposure of mosquitoes to the Esp_Z bacterium for interruption of malaria transmission. Methods The ability of Esp_Z to colonize Anopheles gambiae midguts harbouring microbiota derived from wild mosquitoes was determined by qPCR. Upon introduction of Esp_Z via nectar feeding, the permissiveness of colonized mosquitoes to Plasmodium falciparum infection was determined, as well as the impact of Esp_Z on mosquito fitness parameters, such as longevity, number of eggs laid and number of larvae hatched. The genome of Esp_Z was sequenced, and transcriptome analyses were performed to identify bacterial genes that are important for colonization of the mosquito midgut, as well as for ROS-production. A gene expression analysis of members of the oxidative defence pathway of Plasmodium berghei was also conducted to assess the parasite’s oxidative defence response to Esp_Z exposure. Results Esp_Z persisted for up to 4 days in the An. gambiae midgut after introduction via nectar feeding, and was able to significantly inhibit Plasmodium sporogonic development. Introduction of this bacterium did not adversely affect mosquito fitness. Candidate genes involved in the selection of a better fit Esp_Z to the mosquito midgut environment and in its ability to condition oxidative status of its surroundings were identified, and parasite expression data indicated that Esp_Z is able to induce a partial and temporary shutdown of the ookinetes antioxidant response. Conclusions Esp_Z is capable of inhibiting sporogonic development of Plasmodium in the presence of the mosquito’s native microbiota without affecting mosquito fitness. Several candidate bacterial genes are likely mediating midgut colonization and ROS production, and inhibition of Plasmodium development appears to involve a shutdown of the parasite’s oxidative defence system. A better understanding of the complex reciprocal tripartite interactions can facilitate the development and optimization of an Esp_Z-based malaria control strategy. Electronic supplementary material The online version of this article (doi:10.1186/s12936-016-1468-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Nathan J Dennison
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Raúl G Saraiva
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Chris M Cirimotich
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Godfree Mlambo
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Emmanuel F Mongodin
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
16
|
A 2-Cys peroxiredoxin in response to oxidative stress in the pine wood nematode, Bursaphelenchus xylophilus. Sci Rep 2016; 6:27438. [PMID: 27271000 PMCID: PMC4895224 DOI: 10.1038/srep27438] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 05/12/2016] [Indexed: 12/11/2022] Open
Abstract
The pine wood nematode, Bursaphelenchus xylophilus, is the causal agent of pine wilt disease that has devastated pine forests in Asia. Parasitic nematodes are known to have evolved antioxidant stress responses that defend against host plant defenses. In this study, the infestation of whitebark pine, Pinus bungean, with B. xylophilus led to a significant increase in plant hydrogen peroxide (H2O2) and salicylic acid levels. Correspondingly, the expression of an antioxidative enzyme, 2-Cysteine peroxiredoxin (BxPrx), was elevated in B. xylophilus following the H2O2 treatments. Recombinant BxPrx, a thermal stabile and pH tolerant enzyme, exhibited high level of antioxidant activity against H2O2, suggesting that it is capable of protecting cells from free radical attacks. Immunohistochemical localization study showed that BxPrx was broadly expressed across different tissues and could be secreted outside the nematode. Finally, the number of BxPrx homologs in both dauer-like and fungi-feeding B. xylophilus were comparable based on bioinformatics analysis of existing EST libraries, indicating a potential role of BxPrx in both propagative and dispersal nematodes. These combined results suggest that BxPrx is a key genetic factor facilitating the infestation and distribution of B. xylophilus within pine hosts, and consequently the spread of pine wilt disease.
Collapse
|
17
|
Orian L, Mauri P, Roveri A, Toppo S, Benazzi L, Bosello-Travain V, De Palma A, Maiorino M, Miotto G, Zaccarin M, Polimeno A, Flohé L, Ursini F. Selenocysteine oxidation in glutathione peroxidase catalysis: an MS-supported quantum mechanics study. Free Radic Biol Med 2015; 87:1-14. [PMID: 26163004 DOI: 10.1016/j.freeradbiomed.2015.06.011] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 05/18/2015] [Accepted: 06/09/2015] [Indexed: 12/31/2022]
Abstract
Glutathione peroxidases (GPxs) are enzymes working with either selenium or sulfur catalysis. They adopted diverse functions ranging from detoxification of H(2)O(2) to redox signaling and differentiation. The relative stability of the selenoenzymes, however, remained enigmatic in view of the postulated involvement of a highly unstable selenenic acid form during catalysis. Nevertheless, density functional theory calculations obtained with a representative active site model verify the mechanistic concept of GPx catalysis and underscore its efficiency. However, they also allow that the selenenic acid, in the absence of the reducing substrate, reacts with a nitrogen in the active site. MS/MS analysis of oxidized rat GPx4 complies with the predicted structure, an 8-membered ring, in which selenium is bound as selenenylamide to the protein backbone. The intermediate can be re-integrated into the canonical GPx cycle by glutathione, whereas, under denaturing conditions, its selenium moiety undergoes β-cleavage with formation of a dehydro-alanine residue. The selenenylamide bypass prevents destruction of the redox center due to over-oxidation of the selenium or its elimination and likely allows fine-tuning of GPx activity or alternate substrate reactions for regulatory purposes.
Collapse
Affiliation(s)
- Laura Orian
- Department of Chemistry, University of Padova, Italy
| | - Pierluigi Mauri
- Institute for Biomedical Technologies, National Research Council, Milano, Italy
| | | | - Stefano Toppo
- Department of Molecular Medicine, University of Padova, Italy
| | - Louise Benazzi
- Institute for Biomedical Technologies, National Research Council, Milano, Italy
| | | | - Antonella De Palma
- Institute for Biomedical Technologies, National Research Council, Milano, Italy
| | | | - Giovanni Miotto
- Department of Molecular Medicine, University of Padova, Italy
| | - Mattia Zaccarin
- Department of Molecular Medicine, University of Padova, Italy
| | | | - Leopold Flohé
- Department of Molecular Medicine, University of Padova, Italy.
| | - Fulvio Ursini
- Department of Molecular Medicine, University of Padova, Italy
| |
Collapse
|
18
|
|
19
|
Role and Regulation of Glutathione Metabolism in Plasmodium falciparum. Molecules 2015; 20:10511-34. [PMID: 26060916 PMCID: PMC6272303 DOI: 10.3390/molecules200610511] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 05/11/2015] [Accepted: 06/01/2015] [Indexed: 11/30/2022] Open
Abstract
Malaria in humans is caused by one of five species of obligate intracellular protozoan parasites of the genus Plasmodium. P. falciparum causes the most severe disease and is responsible for 600,000 deaths annually, primarily in Sub-Saharan Africa. It has long been suggested that during their development, malaria parasites are exposed to environmental and metabolic stresses. One strategy to drug discovery was to increase these stresses by interfering with the parasites’ antioxidant and redox systems, which may be a valuable approach to disease intervention. Plasmodium possesses two redox systems—the thioredoxin and the glutathione system—with overlapping but also distinct functions. Glutathione is the most abundant low molecular weight redox active thiol in the parasites existing primarily in its reduced form representing an excellent thiol redox buffer. This allows for an efficient maintenance of the intracellular reducing environment of the parasite cytoplasm and its organelles. This review will highlight the mechanisms that are responsible for sustaining an adequate concentration of glutathione and maintaining its redox state in Plasmodium. It will provide a summary of the functions of the tripeptide and will discuss the potential of glutathione metabolism for drug discovery against human malaria parasites.
Collapse
|
20
|
Maiorino M, Bosello-Travain V, Cozza G, Miotto G, Roveri A, Toppo S, Zaccarin M, Ursini F. Understanding mammalian glutathione peroxidase 7 in the light of its homologs. Free Radic Biol Med 2015; 83:352-60. [PMID: 25724691 DOI: 10.1016/j.freeradbiomed.2015.02.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 02/09/2015] [Accepted: 02/14/2015] [Indexed: 01/24/2023]
Abstract
The glutathione peroxidase homologs (GPxs) efficiently reduce hydroperoxides using electrons from glutathione (GSH), thioredoxin (Trx), or protein disulfide isomerase (PDI). Trx is preferentially used by the GPxs of the majority of bacteria, invertebrates, plants, and fungi. GSH or PDI, instead, is preferentially used by vertebrate GPxs that operate by Sec or Cys catalysis, respectively. Mammalian GPx7 and GPx8 are unique homologs that contain a peroxidatic Cys (CP). Being reduced by PDI and located within the endoplasmic reticulum (ER), these enzymes have been involved in oxidative protein folding. Kinetic analysis indicates that oxidation of PDI by recombinant GPx7 occurs at a much faster rate than that of GSH. Nonetheless, activity measurement suggests that, at physiological concentrations, a competition between these two substrates takes place, with the rate of PDI oxidation by GPx7 controlled by the concentration of GSH, whereas the GSSG produced in the competing reaction contributes to the ER redox buffer. A mechanism has been proposed for GPx7 involving two Cys residues, in which an intramolecular disulfide of the CP is formed with an alleged resolving Cys (CR) located in the strongly conserved FPCNQ motif (C86 in humans), a noncanonical position in GPxs. Kinetic measurements and comparison with the other thiol peroxidases containing a functional CR suggest that a resolving function of C86 in the catalytic cycle is very unlikely. We propose that GPx7 is catalytically active as a 1-Cys-GPx, in which CP both reduces H2O2 and oxidizes PDI, and that the CP-C86 disulfide has instead the role of stabilizing the oxidized peroxidase in the absence of the reducing substrate.
Collapse
Affiliation(s)
- Matilde Maiorino
- Department of Molecular Medicine and University of Padova, I-35121 Padova, Italy.
| | | | - Giorgio Cozza
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy
| | - Giovanni Miotto
- Department of Molecular Medicine and University of Padova, I-35121 Padova, Italy
| | - Antonella Roveri
- Department of Molecular Medicine and University of Padova, I-35121 Padova, Italy
| | - Stefano Toppo
- Department of Molecular Medicine and University of Padova, I-35121 Padova, Italy
| | - Mattia Zaccarin
- Department of Molecular Medicine and University of Padova, I-35121 Padova, Italy
| | - Fulvio Ursini
- Department of Molecular Medicine and University of Padova, I-35121 Padova, Italy
| |
Collapse
|
21
|
Molecular cloning, characterization and expression profile of a glutathione peroxidase-like thioredoxin peroxidase (TPxGl) of the rodent malaria parasite Plasmodium berghei. Parasitol Int 2015; 64:282-9. [DOI: 10.1016/j.parint.2014.02.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 01/15/2014] [Accepted: 02/24/2014] [Indexed: 01/07/2023]
|
22
|
Ye ZW, Zhang J, Townsend DM, Tew KD. Oxidative stress, redox regulation and diseases of cellular differentiation. Biochim Biophys Acta Gen Subj 2014; 1850:1607-21. [PMID: 25445706 DOI: 10.1016/j.bbagen.2014.11.010] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 10/31/2014] [Accepted: 11/10/2014] [Indexed: 12/18/2022]
Abstract
BACKGROUND Within cells, there is a narrow concentration threshold that governs whether reactive oxygen species (ROS) induce toxicity or act as second messengers. SCOPE OF REVIEW We discuss current understanding of how ROS arise, facilitate cell signaling, cause toxicities and disease related to abnormal cell differentiation and those (primarily) sulfur based pathways that provide nucleophilicity to offset these effects. PRIMARY CONCLUSIONS Cellular redox homeostasis mediates a plethora of cellular pathways that determine life and death events. For example, ROS intersect with GSH based enzyme pathways to influence cell differentiation, a process integral to normal hematopoiesis, but also affecting a number of diverse cell differentiation related human diseases. Recent attempts to manage such pathologies have focused on intervening in some of these pathways, with the consequence that differentiation therapy targeting redox homeostasis has provided a platform for drug discovery and development. GENERAL SIGNIFICANCE The balance between electrophilic oxidative stress and protective biomolecular nucleophiles predisposes the evolution of modern life forms. Imbalances of the two can produce aberrant redox homeostasis with resultant pathologies. Understanding the pathways involved provides opportunities to consider interventional strategies. This article is part of a Special Issue entitled Redox regulation of differentiation and de-differentiation.
Collapse
Affiliation(s)
- Zhi-Wei Ye
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, 70 President St., DD410, Charleston, SC 29425, USA
| | - Jie Zhang
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, 70 President St., DD410, Charleston, SC 29425, USA
| | - Danyelle M Townsend
- Department of Pharmaceutical and Biomedical Sciences, Medical University of South Carolina, 274 Calhoun Street MSC 141, Charleston, SC 29425-1410, USA
| | - Kenneth D Tew
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, 70 President St., DD410, Charleston, SC 29425, USA.
| |
Collapse
|
23
|
Usui M, Masuda-Suganuma H, Fukumoto S, Angeles JMM, Hakimi H, Inoue N, Kawazu SI. Effect of thioredoxin peroxidase-1 gene disruption on the liver stages of the rodent malaria parasite Plasmodium berghei. Parasitol Int 2014; 64:290-4. [PMID: 25284813 DOI: 10.1016/j.parint.2014.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 09/23/2014] [Accepted: 09/28/2014] [Indexed: 11/30/2022]
Abstract
Phenotypic observation of thioredoxin peroxidase-1 (TPx-1) gene-disrupted Plasmodium berghei (TPx-1 KO) in the liver-stage was performed with an in vitro infection system in order to investigate defective liver-stage development in a mouse infection model. Indirect immunofluorescence microscopy assay with anti-circumsporozoite protein antibody revealed that in the liver schizont stage, TPx-1 KO parasite cells were significantly smaller than cells of the wild-type parent strain (WT). Indirect immunofluorescence microscopy assay with anti-merozoite surface protein-1 antibody, which was used to evaluate late schizont-stage development, indicated that TPx-1 KO schizont development was similar to WT strain development towards the merozoite-forming stage (mature schizont). However, fewer merozoites were produced in the mature TPx-1 KO schizont than in the mature WT schizont. Taken together, the results suggest that TPx-1 may be involved in merozoite formation during liver schizont development.
Collapse
Affiliation(s)
- Miho Usui
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, 2-13 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
| | - Hirono Masuda-Suganuma
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, 2-13 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
| | - Shinya Fukumoto
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, 2-13 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
| | - Jose Ma M Angeles
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, 2-13 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
| | - Hassan Hakimi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, 2-13 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
| | - Noboru Inoue
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, 2-13 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
| | - Shin-Ichiro Kawazu
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, 2-13 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
| |
Collapse
|
24
|
Vivian D, Polli JE. Mechanistic interpretation of conventional Michaelis-Menten parameters in a transporter system. Eur J Pharm Sci 2014; 64:44-52. [PMID: 25169756 DOI: 10.1016/j.ejps.2014.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 07/22/2014] [Accepted: 08/17/2014] [Indexed: 11/24/2022]
Abstract
The aim was to elucidate how steps in drug translocation by a solute carrier transporter impact Michaelis-Menten parameters Km, Ki, and Vmax. The first objective was to derive a model for carrier-mediated substrate translocation and perform sensitivity analysis with regard to the impact of individual microrate constants on Km, Ki, and Vmax. The second objective was to compare underpinning microrate constants between compounds translocated by the same transporter. Equations for Km, Ki, and Vmax were derived from a six-state model involving unidirectional transporter flipping and reconfiguration. This unidirectional model is applicable to co-transporter type solute carriers, like the apical sodium-dependent bile acid transporter (ASBT) and the proton-coupled peptide cotransporter (PEPT1). Sensitivity analysis identified the microrate constants that impacted Km, Ki, and Vmax. Compound comparison using the six-state model employed regression to identify microrate constant values that can explain observed Km and Vmax values. Results yielded some expected findings, as well as some unanticipated effects of microrate constants on Km, Ki, and Vmax. Km and Ki were found to be equal for inhibitors that are also substrates. Additionally, microrate constant values for certain steps in transporter functioning influenced Km and Vmax to be low or high.
Collapse
Affiliation(s)
- Diana Vivian
- University of Maryland School of Pharmacy, Baltimore, MD 21201, USA
| | - James E Polli
- University of Maryland School of Pharmacy, Baltimore, MD 21201, USA.
| |
Collapse
|
25
|
Analysis of the expression and antioxidant activity of 2-Cys peroxiredoxin protein in Fasciola gigantica. Exp Parasitol 2014; 140:24-32. [DOI: 10.1016/j.exppara.2014.02.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 01/03/2014] [Accepted: 02/09/2014] [Indexed: 11/20/2022]
|
26
|
Prabhu P, Singh BG, Noguchi M, Phadnis PP, Jain VK, Iwaoka M, Priyadarsini KI. Stable selones in glutathione-peroxidase-like catalytic cycle of selenonicotinamide derivative. Org Biomol Chem 2014; 12:2404-12. [DOI: 10.1039/c3ob42336k] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Stable selone formation in 2,2′-diselenobis[3-amidopyridine], reduces unwanted sulfur exchange reaction in glutathione peroxidase like catalytic cycle and enhances its enzyme activity.
Collapse
Affiliation(s)
- Parashiva Prabhu
- Chemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400 085, India
| | - Beena G. Singh
- Radiation & Photochemistry Division
- Bhabha Atomic Research Centre
- Mumbai – 400 085, India
| | - Masato Noguchi
- Department of Chemistry
- School of Science
- Tokai University
- Kanagawa 259-1292, Japan
| | - Prasad P. Phadnis
- Chemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400 085, India
| | - Vimal K. Jain
- Chemistry Division
- Bhabha Atomic Research Centre
- Mumbai 400 085, India
| | - Michio Iwaoka
- Department of Chemistry
- School of Science
- Tokai University
- Kanagawa 259-1292, Japan
| | | |
Collapse
|
27
|
Gauthier LD, Greenstein JL, O'Rourke B, Winslow RL. An integrated mitochondrial ROS production and scavenging model: implications for heart failure. Biophys J 2013; 105:2832-42. [PMID: 24359755 PMCID: PMC3882515 DOI: 10.1016/j.bpj.2013.11.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 08/30/2013] [Accepted: 11/05/2013] [Indexed: 12/27/2022] Open
Abstract
It has been observed experimentally that cells from failing hearts exhibit elevated levels of reactive oxygen species (ROS) upon increases in energetic workload. One proposed mechanism for this behavior is mitochondrial Ca(2+) mismanagement that leads to depletion of ROS scavengers. Here, we present a computational model to test this hypothesis. Previously published models of ROS production and scavenging were combined and reparameterized to describe ROS regulation in the cellular environment. Extramitochondrial Ca(2+) pulses were applied to simulate frequency-dependent changes in cytosolic Ca(2+). Model results show that decreased mitochondrial Ca(2+)uptake due to mitochondrial Ca(2+) uniporter inhibition (simulating Ru360) or elevated cytosolic Na(+), as in heart failure, leads to a decreased supply of NADH and NADPH upon increasing cellular workload. Oxidation of NADPH leads to oxidation of glutathione (GSH) and increased mitochondrial ROS levels, validating the Ca(2+) mismanagement hypothesis. The model goes on to predict that the ratio of steady-state [H2O2]m during 3Hz pacing to [H2O2]m at rest is highly sensitive to the size of the GSH pool. The largest relative increase in [H2O2]m in response to pacing is shown to occur when the total GSH and GSSG is close to 1 mM, whereas pool sizes below 0.9 mM result in high resting H2O2 levels, a quantitative prediction only possible with a computational model.
Collapse
Affiliation(s)
- Laura D Gauthier
- Institute for Computational Medicine and Department of Biomedical Engineering, The Johns Hopkins University School of Medicine and Whiting School of Engineering, Baltimore, Maryland.
| | - Joseph L Greenstein
- Institute for Computational Medicine and Department of Biomedical Engineering, The Johns Hopkins University School of Medicine and Whiting School of Engineering, Baltimore, Maryland
| | - Brian O'Rourke
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore Maryland
| | - Raimond L Winslow
- Institute for Computational Medicine and Department of Biomedical Engineering, The Johns Hopkins University School of Medicine and Whiting School of Engineering, Baltimore, Maryland
| |
Collapse
|
28
|
Characterization of biochemical properties of a selenium-independent glutathione peroxidase ofCryptosporidium parvum. Parasitology 2013; 141:570-8. [DOI: 10.1017/s0031182013001832] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
SUMMARYGlutathione peroxidase (GPx; EC 1.11.1.9) is an important antioxidant enzyme that catalyses the reduction of organic and inorganic hydroperoxides to water in oxygen-consuming organisms, using glutathione as an electron donor. Here, we report the characterization of a GPx ofCryptosporidium parvum(CpGPx). CpGPx contained a standard UGU codon for cysteine instead of a UGA opal codon for seleno-cysteine (SeCys) at the active site, and no SeCys insertion sequence (SECIS) motif was identified within the 3′-untranslated region (UTR) of CpGPx, which suggested its selenium-independent nature.In silicoand biochemical analyses indicated that CpGPx is a cytosolic protein with a monomeric structure. Recombinant CpGPx was active over a wide pH range and was stable under physiological conditions. It showed a substrate preference against organic hydroperoxides, such as cumene hydroperoxide andt-butyl hydroperoxide, but it also showed activity against inorganic hydroperoxide, hydrogen peroxide. Recombinant CpGPx was not inhibited by potassium cyanide or by sodium azide. The enzyme effectively protected DNA and protein from oxidative damage induced by hydrogen peroxide, and was functionally expressed in various developmental stages ofC. parvum. These results collectively suggest the essential role of CpGPx for the parasite's antioxidant defence system.
Collapse
|
29
|
|
30
|
Kembro JM, Aon MA, Winslow RL, O'Rourke B, Cortassa S. Integrating mitochondrial energetics, redox and ROS metabolic networks: a two-compartment model. Biophys J 2013; 104:332-43. [PMID: 23442855 DOI: 10.1016/j.bpj.2012.11.3808] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2012] [Revised: 11/14/2012] [Accepted: 11/27/2012] [Indexed: 12/18/2022] Open
Abstract
To understand the mechanisms involved in the control and regulation of mitochondrial reactive oxygen species (ROS) levels, a two-compartment computational mitochondrial energetic-redox (ME-R) model accounting for energetic, redox, and ROS metabolisms is presented. The ME-R model incorporates four main redox couples (NADH/NAD(+), NADPH/NADP(+), GSH/GSSG, Trx(SH)(2)/TrxSS). Scavenging systems-glutathione, thioredoxin, superoxide dismutase, catalase-are distributed in mitochondrial matrix and extra-matrix compartments, and transport between compartments of ROS species (superoxide: O(2)(⋅-), hydrogen peroxide: H(2)O(2)), and GSH is also taken into account. Model simulations are compared with experimental data obtained from isolated heart mitochondria. The ME-R model is able to simulate: i), the shape and order of magnitude of H(2)O(2) emission and dose-response kinetics observed after treatment with inhibitors of the GSH or Trx scavenging systems and ii), steady and transient behavior of ΔΨ(m) and NADH after single or repetitive pulses of substrate- or uncoupler-elicited energetic-redox transitions. The dynamics of the redox environment in both compartments is analyzed with the model following substrate addition. The ME-R model represents a useful computational tool for exploring ROS dynamics, the role of compartmentation in the modulation of the redox environment, and how redox regulation participates in the control of mitochondrial function.
Collapse
Affiliation(s)
- Jackelyn M Kembro
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore Maryland, USA
| | | | | | | | | |
Collapse
|
31
|
Flohé L, Jaeger T, Pilawa S, Sztajer H. Thiol-dependent peroxidases care little about homology-based assignments of function. Redox Rep 2013; 8:256-64. [PMID: 14962360 DOI: 10.1179/135100003225002862] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Thiol-dependent peroxidase systems are reviewed with special emphasis on their potential use as drug targets. The basic catalytic mechanism of the two major thiol-peroxidase families, the glutathione peroxidases and the peroxiredoxins, are reasonably well understood. Sequence-based predictions of substrate specificities are still unsatisfactory. GPx-type enzymes are not generally specific for GSH but may specifically react with CXXC motifs as present in thioredoxins or tryparedoxins. Inversely, the peroxiredoxin family that was believed to be specific for CXXC-type proteins, also comprises glutathione peroxidases. Since structure-based predictions of function are also limited by small data bases, the increasing number of sequences emerging from genome projects require enzymatic characterization and genetic proof of relevance before they can be classified as drug targets.
Collapse
Affiliation(s)
- L Flohé
- Department of Biochemistry, Technical University of Braunschweig, Braunschweig, Germany.
| | | | | | | |
Collapse
|
32
|
Protein disulfide isomerase and glutathione are alternative substrates in the one Cys catalytic cycle of glutathione peroxidase 7. Biochim Biophys Acta Gen Subj 2013; 1830:3846-57. [DOI: 10.1016/j.bbagen.2013.02.017] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 02/11/2013] [Accepted: 02/19/2013] [Indexed: 11/24/2022]
|
33
|
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]
|
34
|
Turturice BA, Lamm MA, Tasch JJ, Zalewski A, Kooistra R, Schroeter EH, Sharma S, Kawazu SI, Kanzok SM. Expression of cytosolic peroxiredoxins in Plasmodium berghei ookinetes is regulated by environmental factors in the mosquito bloodmeal. PLoS Pathog 2013; 9:e1003136. [PMID: 23382676 PMCID: PMC3561267 DOI: 10.1371/journal.ppat.1003136] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Accepted: 11/29/2012] [Indexed: 11/19/2022] Open
Abstract
The Plasmodium ookinete develops over several hours in the bloodmeal of its mosquito vector where it is exposed to exogenous stresses, including cytotoxic reactive oxygen species (ROS). How the parasite adapts to these challenging conditions is not well understood. We have systematically investigated the expression of three cytosolic antioxidant proteins, thioredoxin-1 (Trx-1), peroxiredoxin-1 (TPx-1), and 1-Cys peroxiredoxin (1-Cys Prx), in developing ookinetes of the rodent parasite Plasmodium berghei under various growth conditions. Transcriptional profiling showed that tpx-1 and 1-cys prx but not trx-1 are more strongly upregulated in ookinetes developing in the mosquito bloodmeal when compared to ookinetes growing under culture conditions. Confocal immunofluorescence imaging revealed comparable expression patterns on the corresponding proteins. 1-Cys Prx in particular exhibited strong expression in mosquito-derived ookinetes but was not detectable in cultured ookinetes. Furthermore, ookinetes growing in culture upregulated tpx-1 and 1-cys prx when challenged with exogenous ROS in a dose-dependent fashion. This suggests that environmental factors in the mosquito bloodmeal induce upregulation of cytosolic antioxidant proteins in Plasmodium ookinetes. We found that in a parasite line lacking TPx-1 (TPx-1KO), expression of 1-Cys Prx occurred significantly earlier in mosquito-derived TPx-1KO ookinetes when compared to wild type (WT) ookinetes. The protein was also readily detectable in cultured TPx-1KO ookinetes, indicating that 1-Cys Prx at least in part compensates for the loss of TPx-1 in vivo. We hypothesize that this dynamic expression of the cytosolic peroxiredoxins reflects the capacity of the developing Plasmodium ookinete to rapidly adapt to the changing conditions in the mosquito bloodmeal. This would significantly increase its chances of survival, maturation and subsequent escape. Our results also emphasize that environmental conditions must be taken into account when investigating Plasmodium-mosquito interactions. The malaria parasite Plasmodium is transmitted by Anopheles mosquitoes. Within the midgut of the insect, it is exposed to multiple environmental stresses, including cytotoxic reactive oxygen species (ROS). To avoid destruction, the parasite develops into a motile ookinete capable of leaving the midgut. Yet, ookinete development lasts over several hours and requires the parasite to adapt to an increasingly challenging environment. Here we show that ookinetes of the rodent parasite Plasmodium berghei during development in the mosquito midgut increase the expression of the protective antioxidant proteins peroxiredoxin-1 (TPx-1) and 1-Cys peroxiredoxin (1-Cys Prx). This upregulation was also inducible in cultured ookinetes by challenging them with ROS. This suggests that ookinetes actively modulate the expression of their antioxidant proteins in response to the changing conditions in the mosquito. We also found that ookinetes lacking TPx-1 (TPx-1KO) upregulated 1-Cys Prx expression significantly earlier than wild type ookinetes. This indicates that the TPx-1KO parasites compensate for the loss of TPx-1 by altering the expression pattern of the functionally related 1-Cys Prx. The observed dynamic regulation of the cytosolic antioxidant proteins may help the Plasmodium ookinete to adapt to rapidly changing environmental conditions and thus to increase the probability of survival, maturation and escape from the mosquito midgut.
Collapse
Affiliation(s)
- Benjamin A. Turturice
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Michael A. Lamm
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - James J. Tasch
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Angelika Zalewski
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Rachel Kooistra
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Eric H. Schroeter
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
| | - Sapna Sharma
- Department of Biology, York University, Toronto, Ontario, Canada
| | - Shin-Ichiro Kawazu
- Obihiro University of Agriculture and Veterinarian Medicine, National Research Center for Protozoan Diseases, Obihiro, Hokkaido, Japan
| | - Stefan M. Kanzok
- Department of Biology, Loyola University Chicago, Chicago, Illinois, United States of America
- * E-mail:
| |
Collapse
|
35
|
Lehane AM, McDevitt CA, Kirk K, Fidock DA. Degrees of chloroquine resistance in Plasmodium - is the redox system involved? INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2012; 2:47-57. [PMID: 22773965 DOI: 10.1016/j.ijpddr.2011.11.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Chloroquine (CQ) was once a very effective antimalarial drug that, at its peak, was consumed in the hundreds of millions of doses per year. The drug acts against the Plasmodium parasite during the asexual intraerythrocytic phase of its lifecycle. Unfortunately, clinical resistance to this drug is now widespread. Questions remain about precisely how CQ kills malaria parasites, and by what means some CQ-resistant (CQR) parasites can withstand much higher concentrations of the drug than others that also fall in the CQR category. In this review we investigate the evidence for and against the proposal that CQ kills parasites by generating oxidative stress. Further, we examine a long-held idea that the glutathione system of malaria parasites plays a role in CQ resistance. We conclude that there is strong evidence that glutathione levels modulate CQ response in the rodent malaria species P. berghei, but that a role for redox in contributing to the degree of CQ resistance in species infectious to humans has not been firmly established.
Collapse
Affiliation(s)
- Adele M Lehane
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | | | | | | |
Collapse
|
36
|
Wei PC, Hsieh YH, Su MI, Jiang X, Hsu PH, Lo WT, Weng JY, Jeng YM, Wang JM, Chen PL, Chang YC, Lee KF, Tsai MD, Shew JY, Lee WH. Loss of the oxidative stress sensor NPGPx compromises GRP78 chaperone activity and induces systemic disease. Mol Cell 2012; 48:747-59. [PMID: 23123197 DOI: 10.1016/j.molcel.2012.10.007] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 07/16/2012] [Accepted: 09/17/2012] [Indexed: 01/10/2023]
Abstract
NPGPx is a member of the glutathione peroxidase (GPx) family; however, it lacks GPx enzymatic activity due to the absence of a critical selenocysteine residue, rendering its function an enigma. Here, we show that NPGPx is a newly identified stress sensor that transmits oxidative stress signals by forming the disulfide bond between its Cys57 and Cys86 residues. This oxidized form of NPGPx binds to glucose-regulated protein (GRP)78 and forms covalent bonding intermediates between Cys86 of NPGPx and Cys41/Cys420 of GRP78. Subsequently, the formation of the disulfide bond between Cys41 and Cys420 of GRP78 enhances its chaperone activity. NPGPx-deficient cells display increased reactive oxygen species, accumulated misfolded proteins, and impaired GRP78 chaperone activity. Complete loss of NPGPx in animals causes systemic oxidative stress, increases carcinogenesis, and shortens life span. These results suggest that NPGPx is essential for releasing excessive ER stress by enhancing GRP78 chaperone activity to maintain physiological homeostasis.
Collapse
Affiliation(s)
- Pei-Chi Wei
- Genomics Research Center, Academia Sinica, Taipei, 115, Taiwan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
|
38
|
Chaudhari R, Narayan A, Patankar S. A novel trafficking pathway inPlasmodium falciparumfor the organellar localization of glutathione peroxidase-like thioredoxin peroxidase. FEBS J 2012; 279:3872-88. [DOI: 10.1111/j.1742-4658.2012.08746.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 07/11/2012] [Accepted: 08/09/2012] [Indexed: 11/28/2022]
Affiliation(s)
- Rahul Chaudhari
- Department of Biosciences and Bioengineering; IIT Bombay; Mumbai; India
| | - Aishwarya Narayan
- Department of Biosciences and Bioengineering; IIT Bombay; Mumbai; India
| | - Swati Patankar
- Department of Biosciences and Bioengineering; IIT Bombay; Mumbai; India
| |
Collapse
|
39
|
Gaber A, Ogata T, Maruta T, Yoshimura K, Tamoi M, Shigeoka S. The involvement of Arabidopsis glutathione peroxidase 8 in the suppression of oxidative damage in the nucleus and cytosol. PLANT & CELL PHYSIOLOGY 2012; 53:1596-606. [PMID: 22773682 DOI: 10.1093/pcp/pcs100] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A family of eight genes with homology to mammalian glutathione peroxidase (GPX) isoenzymes, designated AtGPX1-AtGPX8, has been identified in Arabidopsis thaliana. In this study we demonstrated the functional analysis of Arabidopsis AtGPX8 with peroxidase activity toward H(2)O(2) and lipid hydroperoxides using thioredoxin as an electron donor. The transcript and protein levels of AtGPX8 in Arabidopsis were up-regulated coordinately in response to oxidative damage caused by high-light (HL) stress or treatment with paraquat (PQ). Furthermore, the knockout Arabidopsis mutants of AtGPX8 (KO-gpx8) exhibited increased sensitivity to oxidative damage caused by PQ treatment in root elongation compared with the wild-type plants. In contrast, transgenic lines overexpressing AtGPX8 (Ox-AtGPX8) were less sensitive to oxidative damage than the wild-type plants. The levels of oxidized proteins in the KO-gpx8 and Ox-AtGPX8 lines were enhanced and suppressed, respectively, compared with the wild-type plants under HL stress or PQ treatment. The fusion protein of AtGPX8 tagged with green fluorescent protein was localized in the cytosol and nucleus of onion epidermal cells. In addition, the AtGPX8 protein was detected in the cytosolic and nuclear fractions prepared from leaves of Arabidopsis plants using the AtGPX8 antibody. Oxidative DNA damage under treatment with PQ increased in the wild-type and KO-gpx8 plants, while it decreased in the OX-AtGPX8 plants. These results suggest that AtGPX8 plays an important role in the protection of cellular components including nuclear DNA against oxidative stress.
Collapse
MESH Headings
- 8-Hydroxy-2'-Deoxyguanosine
- Arabidopsis/drug effects
- Arabidopsis/enzymology
- Arabidopsis/genetics
- Arabidopsis/radiation effects
- Arabidopsis Proteins/genetics
- Arabidopsis Proteins/metabolism
- Blotting, Western
- Cell Nucleus/enzymology
- Cytosol/drug effects
- Cytosol/enzymology
- Cytosol/radiation effects
- DNA Damage
- Deoxyguanosine/analogs & derivatives
- Deoxyguanosine/metabolism
- Electrophoresis, Polyacrylamide Gel
- Gene Expression Regulation, Enzymologic/drug effects
- Gene Expression Regulation, Enzymologic/radiation effects
- Gene Expression Regulation, Plant/drug effects
- Gene Expression Regulation, Plant/radiation effects
- Genes, Plant/genetics
- Glutathione Peroxidase/genetics
- Glutathione Peroxidase/metabolism
- Green Fluorescent Proteins/metabolism
- Light
- Oxidation-Reduction/drug effects
- Oxidation-Reduction/radiation effects
- Oxidative Stress/drug effects
- Oxidative Stress/radiation effects
- Paraquat/toxicity
- Recombinant Proteins/metabolism
- Stress, Physiological/drug effects
- Stress, Physiological/genetics
- Stress, Physiological/radiation effects
- Subcellular Fractions/drug effects
- Subcellular Fractions/metabolism
- Subcellular Fractions/radiation effects
- Substrate Specificity/drug effects
- Substrate Specificity/radiation effects
Collapse
Affiliation(s)
- Ahmed Gaber
- Department of Advanced Bioscience, Kinki University, 3327-204 Nakamachi, Nara, 631-8505 Japan
| | | | | | | | | | | |
Collapse
|
40
|
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.
Collapse
|
41
|
Aon MA, Stanley BA, Sivakumaran V, Kembro JM, O'Rourke B, Paolocci N, Cortassa S. Glutathione/thioredoxin systems modulate mitochondrial H2O2 emission: an experimental-computational study. ACTA ACUST UNITED AC 2012; 139:479-91. [PMID: 22585969 PMCID: PMC3362521 DOI: 10.1085/jgp.201210772] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The net emission of hydrogen peroxide (H(2)O(2)) from mitochondria results from the balance between reactive oxygen species (ROS) continuously generated in the respiratory chain and ROS scavenging. The relative contribution of the two major antioxidant systems in the mitochondrial matrix, glutathione (GSH) and thioredoxin (Trx), has not been assessed. In this paper, we examine this key question via combined experimental and theoretical approaches, using isolated heart mitochondria from mouse, rat, and guinea pig. As compared with untreated control mitochondria, selective inhibition of Trx reductase with auranofin along with depletion of GSH with 2,4-dinitrochlorobenzene led to a species-dependent increase in H(2)O(2) emission flux of 17, 11, and 6 fold in state 4 and 15, 7, and 8 fold in state 3 for mouse, rat, and guinea pig mitochondria, respectively. The maximal H(2)O(2) emission as a percentage of the total O(2) consumption flux was 11%/2.3% for mouse in states 4 and 3 followed by 2%/0.25% and 0.74%/0.29% in the rat and guinea pig, respectively. A minimal computational model accounting for the kinetics of GSH/Trx systems was developed and was able to simulate increase in H(2)O(2) emission fluxes when both scavenging systems were inhibited separately or together. Model simulations suggest that GSH/Trx systems act in concert. When the scavenging capacity of either one of them saturates during H(2)O(2) overload, they relieve each other until complete saturation, when maximal ROS emission occurs. Quantitatively, these results converge on the idea that GSH/Trx scavenging systems in mitochondria are both essential for keeping minimal levels of H(2)O(2) emission, especially during state 3 respiration, when the energetic output is maximal. This suggests that the very low levels of H(2)O(2) emission observed during forward electron transport in the respiratory chain are a result of the well-orchestrated actions of the two antioxidant systems working continuously to offset ROS production.
Collapse
Affiliation(s)
- Miguel Antonio Aon
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | | | | | | | | | | |
Collapse
|
42
|
Qiu W, Dong A, Pizarro JC, Botchkarsev A, Min J, Wernimont AK, Hills T, Hui R, Artz JD. Crystal structures from the Plasmodium peroxiredoxins: new insights into oligomerization and product binding. BMC STRUCTURAL BIOLOGY 2012; 12:2. [PMID: 22429898 PMCID: PMC3337327 DOI: 10.1186/1472-6807-12-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 03/19/2012] [Indexed: 11/10/2022]
Abstract
Abstract
Background
Plasmodium falciparum is the protozoan parasite primarily responsible for more than one million malarial deaths, annually, and is developing resistance to current therapies. Throughout its lifespan, the parasite is subjected to oxidative attack, so Plasmodium antioxidant defences are essential for its survival and are targets for disease control.
Results
To further understand the molecular aspects of the Plasmodium redox system, we solved 4 structures of Plasmodium peroxiredoxins (Prx). Our study has confirmed Pv Trx-Px1 to be a hydrogen peroxide (H2O2)-sensitive peroxiredoxin. We have identified and characterized the novel toroid octameric oligomer of Py Trx-Px1, which may be attributed to the interplay of several factors including: (1) the orientation of the conserved surface/buried arginine of the NNLA(I/L)GRS-loop; and (2) the C-terminal tail positioning (also associated with the aforementioned conserved loop) which facilitates the intermolecular hydrogen bond between dimers (in an A-C fashion). In addition, a notable feature of the disulfide bonds in some of the Prx crystal structures is discussed. Finally, insight into the latter stages of the peroxiredoxin reaction coordinate is gained. Our structure of Py Prx6 is not only in the sulfinic acid (RSO2H) form, but it is also with glycerol bound in a way (not previously observed) indicative of product binding.
Conclusions
The structural characterization of Plasmodium peroxiredoxins provided herein provides insight into their oligomerization and product binding which may facilitate the targeting of these antioxidant defences. Although the structural basis for the octameric oligomerization is further understood, the results yield more questions about the biological implications of the peroxiredoxin oligomerization, as multiple toroid configurations are now known. The crystal structure depicting the product bound active site gives insight into the overoxidation of the active site and allows further characterization of the leaving group chemistry.
Collapse
|
43
|
Ishii T, Warabi E, Yanagawa T. Novel roles of peroxiredoxins in inflammation, cancer and innate immunity. J Clin Biochem Nutr 2012; 50:91-105. [PMID: 22448089 PMCID: PMC3303482 DOI: 10.3164/jcbn.11-109] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Accepted: 09/20/2011] [Indexed: 02/06/2023] Open
Abstract
Peroxiredoxins possess thioredoxin or glutathione peroxidase and chaperone-like activities and thereby protect cells from oxidative insults. Recent studies, however, reveal additional functions of peroxiredoxins in gene expression and inflammation-related biological reactions such as tissue repair, parasite infection and tumor progression. Notably, peroxiredoxin 1, the major mammalian peroxiredoxin family protein, directly interacts with transcription factors such as c-Myc and NF-κB in the nucleus. Additionally, peroxiredoxin 1 is secreted from some cells following stimulation with TGF-β and other cytokines and is thus present in plasma and body fluids. Peroxiredoxin 1 is now recognized as one of the pro-inflammatory factors interacting with toll-like receptor 4, which triggers NF-κB activation and other signaling pathways to evoke inflammatory reactions. Some cancer cells release peroxiredoxin 1 to stimulate toll-like receptor 4-mediated signaling for their progression. Interestingly, peroxiredoxins expressed in protozoa and helminth may modulate host immune responses partly through toll-like receptor 4 for their survival and progression in host. Extracellular peroxiredoxin 1 and peroxiredoxin 2 are known to enhance natural killer cell activity and suppress virus-replication in cells. Peroxiredoxin 1-deficient mice show reduced antioxidant activities but also exhibit restrained tissue inflammatory reactions under some patho-physiological conditions. Novel functions of peroxiredoxins in inflammation, cancer and innate immunity are the focus of this review.
Collapse
Affiliation(s)
- Tetsuro Ishii
- Majors of Medical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
| | | | | |
Collapse
|
44
|
Abstract
Thiol peroxidases comprise glutathione peroxidases (GPx) and peroxiredoxins (Prx). The enzymes of both families reduce hydroperoxides with thiols by enzyme-substitution mechanisms. H(2)O(2) and organic hydroperoxides are reduced by all thiol peroxidases, most efficiently by SecGPxs, whereas fast peroxynitrite reduction is more common in Prxs. Reduction of lipid hydroperoxides is the domain of monomeric GPx4-type enzymes and of some Prxs. The catalysis starts with oxidation of an active-site selenocysteine (U(P)) or cysteine (C(P)). Activation of Cys (Sec) for hydroperoxide reduction in the GPx family is achieved by a typical tetrad composed of Cys (Sec), Asn, Gln, and Trp, whereas a triad of Cys Thr (or Ser) and Arg is the signature of Prx. In many of the CysGPxs and Prxs, a second Cys (C(R)) is required. In these 2-CysGPxs and 2-CysPrxs, the C(P) oxidized to a sulfenic acid forms an intra- or intermolecular disulfide (typical 2-CysPrx) with C(R), before a stepwise regeneration of ground-state enzyme by redoxin-type proteins can proceed. In SecGPxs and sporadically in Prxs, GSH is used as the reductant. Diversity combined with structural variability predestines thiol peroxidases for redox regulation via ROOH sensing and direct or indirect transduction of oxidant signals to specific protein targets.
Collapse
Affiliation(s)
- Leopold Flohé
- Otto-von-Guericke-Universität and MOLISA GmbH, Magdeburg, Germany.
| | | | | | | |
Collapse
|
45
|
Foth BJ, Zhang N, Chaal BK, Sze SK, Preiser PR, Bozdech Z. Quantitative time-course profiling of parasite and host cell proteins in the human malaria parasite Plasmodium falciparum. Mol Cell Proteomics 2011; 10:M110.006411. [PMID: 21558492 DOI: 10.1074/mcp.m110.006411] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Studies of the Plasmodium falciparum transcriptome have shown that the tightly controlled progression of the parasite through the intra-erythrocytic developmental cycle (IDC) is accompanied by a continuous gene expression cascade in which most expressed genes exhibit a single transcriptional peak. Because the biochemical and cellular functions of most genes are mediated by the encoded proteins, understanding the relationship between mRNA and protein levels is crucial for inferring biological activity from transcriptional gene expression data. Although studies on other organisms show that <50% of protein abundance variation may be attributable to corresponding mRNA levels, the situation in Plasmodium is further complicated by the dynamic nature of the cyclic gene expression cascade. In this study, we simultaneously determined mRNA and protein abundance profiles for P. falciparum parasites during the IDC at 2-hour resolution based on oligonucleotide microarrays and two-dimensional differential gel electrophoresis protein gels. We find that most proteins are represented by more than one isoform, presumably because of post-translational modifications. Like transcripts, most proteins exhibit cyclic abundance profiles with one peak during the IDC, whereas the presence of functionally related proteins is highly correlated. In contrast, the abundance of most parasite proteins peaks significantly later (median 11 h) than the corresponding transcripts and often decreases slowly in the second half of the IDC. Computational modeling indicates that the considerable and varied incongruence between transcript and protein abundance may largely be caused by the dynamics of translation and protein degradation. Furthermore, we present cyclic abundance profiles also for parasite-associated human proteins and confirm the presence of five human proteins with a potential role in antioxidant defense within the parasites. Together, our data provide fundamental insights into transcript-protein relationships in P. falciparum that are important for the correct interpretation of transcriptional data and that may facilitate the improvement and development of malaria diagnostics and drug therapy.
Collapse
Affiliation(s)
- Bernardo Javier Foth
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | | | | | | | | | | |
Collapse
|
46
|
Kim J, Kim JI, Jang HS, Park JW, Park KM. Protective role of cytosolic NADP(+)-dependent isocitrate dehydrogenase, IDH1, in ischemic pre-conditioned kidney in mice. Free Radic Res 2011; 45:759-66. [PMID: 21506885 DOI: 10.3109/10715762.2011.577426] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ischemic pre-conditioning protects the kidney against subsequent ischemia/reperfusion (I/R). This study investigated the role of cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDH1), a producer of NADPH, in the ischemic pre-conditioning. Mice were pre-conditioned by 30 min of renal ischemia and 8 days of reperfusion. In non-pre-conditioned mice 30 min of ischemia had significantly increased the levels of plasma creatinine, BUN, lipid peroxidation and hydrogen peroxide in kidneys, whereas in pre-conditioned mice, the ischemia did not increase them. The reductions of reduced glutathione and NADPH after I/R were greater in non-pre-conditioned mice than in pre-conditioned mice. Ischemic pre-conditioning prevented the I/R-induced decreases in IDH1 activity and expression, but not in glucose-6-phosphate dehydrogenase activity. In conclusion, protection of the kidney afforded by ischemic pre-conditioning may be associated with increased activity of IDH1 which relates to increased levels of NADPH, increased ratios of GSH/total glutathione, less oxidative stress and less kidney injury induced by subsequent I/R insult.
Collapse
Affiliation(s)
- Jinu Kim
- Department of Anatomy and BK 21 Project, Kyungpook National University School of Medicine, Daegu, 700-422, Republic of Korea
| | | | | | | | | |
Collapse
|
47
|
Richard D, Bartfai R, Volz J, Ralph SA, Muller S, Stunnenberg HG, Cowman AF. A genome-wide chromatin-associated nuclear peroxiredoxin from the malaria parasite Plasmodium falciparum. J Biol Chem 2011; 286:11746-55. [PMID: 21282103 PMCID: PMC3064226 DOI: 10.1074/jbc.m110.198499] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 01/13/2011] [Indexed: 11/16/2022] Open
Abstract
Malaria parasites are subjected to high levels of oxidative stress during their development inside erythrocytes and the ability of the parasite to defend itself against this assault is critical to its survival. Therefore, Plasmodium possesses an effective antioxidant defense system that could potentially be used as a target for the development of inhibitor-based therapy. We have identified an unusual peroxiredoxin protein that localizes to the nucleus of Plasmodium falciparum and have renamed it PfnPrx (PF10_0268, earlier called MCP1). Our work reveals that PfnPrx has a broad specificity of substrate being able to utilize thioredoxin and glutaredoxin as reductants and having the ability to reduce simple and complex peroxides. Intriguingly, chromatin immunoprecipitation followed by deep sequencing reveals that the enzyme associates with chromatin in a genome-wide manner with a slight enrichment in coding regions. Our results represent the first description of a dedicated chromatin-associated peroxiredoxin and potentially represent an ingenious way by which the parasite can survive the highly oxidative environment within its human host.
Collapse
Affiliation(s)
- Dave Richard
- From The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, Australia
| | - Richard Bartfai
- the Department of Molecular Biology, Nijmegen Center of Molecular Life Sciences, Radboud University, Nijmegen 6525 GA, The Netherlands
| | - Jennifer Volz
- From The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, Australia
| | - Stuart A. Ralph
- the Bio21 Molecular Sciences and Biotechnology Institute, University of Melbourne, Melbourne 3052, Australia
| | - Sylke Muller
- the Division of Infection & Immunity and Wellcome Centre for Parasitology, Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom, and
| | - Hendrik G. Stunnenberg
- the Department of Molecular Biology, Nijmegen Center of Molecular Life Sciences, Radboud University, Nijmegen 6525 GA, The Netherlands
| | - Alan F. Cowman
- From The Walter and Eliza Hall Institute of Medical Research, Melbourne 3052, Australia
- the Department of Medical Biology, University of Melbourne, Melbourne 3052, Australia
| |
Collapse
|
48
|
Hudson AL, Sotirchos IM, Davey MW. The activity and hydrogen peroxide sensitivity of the peroxiredoxins from the parasitic nematode Haemonchus contortus. Mol Biochem Parasitol 2011; 176:17-24. [DOI: 10.1016/j.molbiopara.2010.11.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 11/02/2010] [Accepted: 11/03/2010] [Indexed: 01/17/2023]
|
49
|
Kehr S, Sturm N, Rahlfs S, Przyborski JM, Becker K. Compartmentation of redox metabolism in malaria parasites. PLoS Pathog 2010; 6:e1001242. [PMID: 21203490 PMCID: PMC3009606 DOI: 10.1371/journal.ppat.1001242] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Accepted: 11/23/2010] [Indexed: 01/06/2023] Open
Abstract
Malaria, caused by the apicomplexan parasite Plasmodium, still represents a major threat to human health and welfare and leads to about one million human deaths annually. Plasmodium is a rapidly multiplying unicellular organism undergoing a complex developmental cycle in man and mosquito – a life style that requires rapid adaptation to various environments. In order to deal with high fluxes of reactive oxygen species and maintain redox regulatory processes and pathogenicity, Plasmodium depends upon an adequate redox balance. By systematically studying the subcellular localization of the major antioxidant and redox regulatory proteins, we obtained the first complete map of redox compartmentation in Plasmodium falciparum. We demonstrate the targeting of two plasmodial peroxiredoxins and a putative glyoxalase system to the apicoplast, a non-photosynthetic plastid. We furthermore obtained a complete picture of the compartmentation of thioredoxin- and glutaredoxin-like proteins. Notably, for the two major antioxidant redox-enzymes – glutathione reductase and thioredoxin reductase – Plasmodium makes use of alternative-translation-initiation (ATI) to achieve differential targeting. Dual localization of proteins effected by ATI is likely to occur also in other Apicomplexa and might open new avenues for therapeutic intervention. The unicellular parasite Plasmodium falciparum is the causative agent of tropical malaria, which represents a global health burden. In order to survive in its human host and the malaria vector Anopheles, malaria parasites depend on adequate antioxidant defense and efficient redox regulation. Furthermore, as shown by glucose-6 phosphate dehydrogenase deficiency, a genetic variation protecting from malaria, redox equilibrium plays a vital role in parasite pathogenicity. Using a green fluorescent protein reporter gene, we systematically studied the subcellular compartmentation of redox networks in Plasmodium falciparum. Based on our results and data from literature, we provide the first thorough map of redox compartmentation. Most interestingly, for the two major antioxidant redox-enzymes – glutathione reductase (GR) and thioredoxin reductase (TrxR) – Plasmodium falciparum makes use of alternative translation initiation to translate protein isoforms with differing subcellular localization from one gene. Dual localization of proteins due to alternative translation initiation might occur frequently in Apicomplexa and identification of further genes that have evolved alternative translation initiation is likely to offer new therapeutic strategies against this devastating disease.
Collapse
Affiliation(s)
- Sebastian Kehr
- Interdisciplinary Research Centre, Justus Liebig University, Giessen, Germany
| | - Nicole Sturm
- Interdisciplinary Research Centre, Justus Liebig University, Giessen, Germany
| | - Stefan Rahlfs
- Interdisciplinary Research Centre, Justus Liebig University, Giessen, Germany
| | - Jude M. Przyborski
- Department of Parasitology, Faculty of Biology, Philipps University Marburg, Marburg, Germany
| | - Katja Becker
- Interdisciplinary Research Centre, Justus Liebig University, Giessen, Germany
- * E-mail:
| |
Collapse
|
50
|
Abstract
Leopold Flohé is recognized here as a Redox Pioneer because has published a article on antioxidant/redox biology, as first author, that has been cited more than 1,000 times, and more than 20 articles have been cited more than 100 times. He obtained the medical doctorate at the Institute of Pharmacology and Toxicology at the University of Tübingen, Germany, in 1968. He held positions in both Academia (Tübingen, Aachen, and Braunschweig, Germany) and industry (Aachen). He is now operating the biotech company MOLISA in Magdeburg, Germany, while teaching as guest professor at the local university. Dr. Flohé is the pioneer who established the selenoprotein nature of glutathione peroxidase (GPx), the first and, for almost 10 years, the only selenoprotein known in animals. His work was pivotal to link the essential trace element selenium to metabolic processes, which led the Food and Drug Administration (FDA) to approve selenium supplementation for humans in 1980, and stimulated selenium biochemistry in general. In recent years, he embarked on investigating how pathogens protect themselves from oxidative killing. His inseminating studies on the thiol-dependent hydroperoxide metabolism of trypanosomatids and mycobacteria defined molecular drug targets, paving the way to new therapeutic strategies for neglected diseases affecting the people of developing countries.
Collapse
Affiliation(s)
- Fulvio Ursini
- Department of Biological Chemistry, University of Padova, Padova, Italy.
| | | |
Collapse
|