1
|
Libardi SH, Ahmad A, Ferreira FB, Oliveira RJ, Caruso ÍP, Melo FA, de Albuquerque S, Cardoso DR, Burtoloso ACB, Borges JC. Interaction between diterpene icetexanes and old yellow enzymes of Leishmania braziliensis and Trypanosoma cruzi. Int J Biol Macromol 2024; 259:129192. [PMID: 38216013 DOI: 10.1016/j.ijbiomac.2023.129192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 12/21/2023] [Accepted: 12/31/2023] [Indexed: 01/14/2024]
Abstract
Old Yellow Enzymes (OYEs) are flavin-dependent redox enzymes that promote the asymmetric reduction of activated alkenes. Due to the high importance of flavoenzymes in the metabolism of organisms, the interaction between OYEs from the parasites Trypanosoma cruzi and Leishmania braziliensis and three diterpene icetexanes (brussonol and two analogs), were evaluated in the present study, and differences in the binding mechanism and inhibition capacity of these molecules were examined. Although the aforementioned compounds showed poor and negligible activities against T. cruzi and L. braziliensis cells, respectively, the experiments with the purified enzymes indicated that the interaction occurs by divergent mechanisms. Overall, the ligands' inhibitory effect depends on their accessibility to the N5 position of the flavin's isoalloxazine ring. The results also indicated that the OYEs found in both parasites share structural similarities and showed affinities for the diterpene icetexanes in the same range. Nevertheless, the interaction between OYEs and ligands is directed by enthalpy and/or entropy in distinct ways. In conclusion, the binding site of both OYEs exhibits remarkable plasticity, and a large range of different molecules, including that can be substrates and inhibitors, can bind this site. This plasticity should be considered in drug design using OYE as a target.
Collapse
Affiliation(s)
- Silvia H Libardi
- Instituto de Química de São Carlos, Universidade de São Paulo - USP, 13560-970 São Carlos, SP, Brazil
| | - Anees Ahmad
- Instituto de Química de São Carlos, Universidade de São Paulo - USP, 13560-970 São Carlos, SP, Brazil
| | | | - Ronaldo J Oliveira
- Instituto de Ciências Exatas, Naturais e Educação, Universidade Federal do Triângulo Mineiro, 38064-200 Uberaba, MG, Brazil
| | - Ícaro P Caruso
- Instituto de Biociências, Letras e Ciências Exatas (IBILCE) - UNESP, 15054-000 São José do Rio Preto, SP, Brazil; Instituto de Bioquímica Médica Leopoldo de Meis and Centro Nacional para Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ, Brazil
| | - Fernando A Melo
- Instituto de Biociências, Letras e Ciências Exatas (IBILCE) - UNESP, 15054-000 São José do Rio Preto, SP, Brazil
| | - Sergio de Albuquerque
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo - USP, Ribeirão Preto, SP CEP 14040-903, Brazil
| | - Daniel R Cardoso
- Instituto de Química de São Carlos, Universidade de São Paulo - USP, 13560-970 São Carlos, SP, Brazil
| | - Antonio C B Burtoloso
- Instituto de Química de São Carlos, Universidade de São Paulo - USP, 13560-970 São Carlos, SP, Brazil
| | - Júlio C Borges
- Instituto de Química de São Carlos, Universidade de São Paulo - USP, 13560-970 São Carlos, SP, Brazil.
| |
Collapse
|
2
|
Lobo-Rojas Á, Quintero-Troconis E, Rondón-Mercado R, Pérez-Aguilar. MC, Concepción JL, Cáceres AJ. Consumption of Galactose by Trypanosoma cruzi Epimastigotes Generates Resistance against Oxidative Stress. Pathogens 2022; 11:1174. [PMID: 36297231 PMCID: PMC9611177 DOI: 10.3390/pathogens11101174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 09/30/2022] [Accepted: 10/08/2022] [Indexed: 11/25/2022] Open
Abstract
In this study, we demonstrate that Trypanosoma cruzi epimastigotes previously grown in LIT medium supplemented with 20 mM galactose and exposed to sub-lethal concentrations of hydrogen peroxide (100 μM) showed two-fold and five-fold viability when compared to epimastigotes grown in LIT medium supplemented with two different glucose concentrations (20 mM and 1.5 mM), respectively. Similar results were obtained when exposing epimastigotes from all treatments to methylene blue 30 μM. Additionally, through differential centrifugation and the selective permeabilization of cellular membranes with digitonin, we found that phosphoglucomutase activity (a key enzyme in galactose metabolism) occurs predominantly within the cytosolic compartment. Furthermore, after partially permeabilizing epimastigotes with digitonin (0.025 mg × mg-1 of protein), intact glycosomes treated with 20 mM galactose released a higher hexose phosphate concentration to the cytosol in the form of glucose-1-phosphate, when compared to intact glycosomes treated with 20 mM glucose, which predominantly released glucose-6-phosphate. These results shine a light on T. cruzi's galactose metabolism and its interplay with mechanisms that enable resistance to oxidative stress.
Collapse
Affiliation(s)
- Ángel Lobo-Rojas
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Ender Quintero-Troconis
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | | | | | | | | |
Collapse
|
3
|
Identification of a proteasome-targeting arylsulfonamide with potential for the treatment of Chagas' disease. Antimicrob Agents Chemother 2021; 66:e0153521. [PMID: 34606338 PMCID: PMC8765320 DOI: 10.1128/aac.01535-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Phenotypic screening identified an arylsulfonamide compound with activity against Trypanosoma cruzi, the causative agent of Chagas’ disease. Comprehensive mode of action studies revealed that this compound primarily targets the T. cruzi proteasome, binding at the interface between β4 and β5 subunits that catalyze chymotrypsin-like activity. A mutation in the β5 subunit of the proteasome was associated with resistance to compound 1, while overexpression of this mutated subunit also reduced susceptibility to compound 1. Further genetically engineered and in vitro-selected clones resistant to proteasome inhibitors known to bind at the β4/β5 interface were cross-resistant to compound 1. Ubiquitinated proteins were additionally found to accumulate in compound 1-treated epimastigotes. Finally, thermal proteome profiling identified malic enzyme as a secondary target of compound 1, although malic enzyme inhibition was not found to drive potency. These studies identify a novel pharmacophore capable of inhibiting the T. cruzi proteasome that may be exploitable for anti-chagasic drug discovery.
Collapse
|
4
|
Allmann S, Wargnies M, Plazolles N, Cahoreau E, Biran M, Morand P, Pineda E, Kulyk H, Asencio C, Villafraz O, Rivière L, Tetaud E, Rotureau B, Mourier A, Portais JC, Bringaud F. Glycerol suppresses glucose consumption in trypanosomes through metabolic contest. PLoS Biol 2021; 19:e3001359. [PMID: 34388147 PMCID: PMC8386887 DOI: 10.1371/journal.pbio.3001359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 08/25/2021] [Accepted: 07/09/2021] [Indexed: 11/18/2022] Open
Abstract
Microorganisms must make the right choice for nutrient consumption to adapt to their changing environment. As a consequence, bacteria and yeasts have developed regulatory mechanisms involving nutrient sensing and signaling, known as "catabolite repression," allowing redirection of cell metabolism to maximize the consumption of an energy-efficient carbon source. Here, we report a new mechanism named "metabolic contest" for regulating the use of carbon sources without nutrient sensing and signaling. Trypanosoma brucei is a unicellular eukaryote transmitted by tsetse flies and causing human African trypanosomiasis, or sleeping sickness. We showed that, in contrast to most microorganisms, the insect stages of this parasite developed a preference for glycerol over glucose, with glucose consumption beginning after the depletion of glycerol present in the medium. This "metabolic contest" depends on the combination of 3 conditions: (i) the sequestration of both metabolic pathways in the same subcellular compartment, here in the peroxisomal-related organelles named glycosomes; (ii) the competition for the same substrate, here ATP, with the first enzymatic step of the glycerol and glucose metabolic pathways both being ATP-dependent (glycerol kinase and hexokinase, respectively); and (iii) an unbalanced activity between the competing enzymes, here the glycerol kinase activity being approximately 80-fold higher than the hexokinase activity. As predicted by our model, an approximately 50-fold down-regulation of the GK expression abolished the preference for glycerol over glucose, with glucose and glycerol being metabolized concomitantly. In theory, a metabolic contest could be found in any organism provided that the 3 conditions listed above are met.
Collapse
Affiliation(s)
- Stefan Allmann
- Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux University, CNRS, Bordeaux, France
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Bordeaux University, CNRS, Bordeaux, France
| | - Marion Wargnies
- Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux University, CNRS, Bordeaux, France
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Bordeaux University, CNRS, Bordeaux, France
| | - Nicolas Plazolles
- Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux University, CNRS, Bordeaux, France
| | - Edern Cahoreau
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
- MetaToul–MetaboHUB, Toulouse, France
| | - Marc Biran
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Bordeaux University, CNRS, Bordeaux, France
| | - Pauline Morand
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Bordeaux University, CNRS, Bordeaux, France
| | - Erika Pineda
- Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux University, CNRS, Bordeaux, France
| | - Hanna Kulyk
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
- MetaToul–MetaboHUB, Toulouse, France
| | - Corinne Asencio
- Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux University, CNRS, Bordeaux, France
| | - Oriana Villafraz
- Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux University, CNRS, Bordeaux, France
| | - Loïc Rivière
- Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux University, CNRS, Bordeaux, France
| | - Emmanuel Tetaud
- Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux University, CNRS, Bordeaux, France
| | - Brice Rotureau
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Department of Parasites and Insect Vectors, INSERM U1201, Institut Pasteur, Paris, France
| | - Arnaud Mourier
- Institute of Biochemistry and Genetics of the Cell (IBGC), CNRS, Bordeaux University, Bordeaux, France
| | - Jean-Charles Portais
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France
- MetaToul–MetaboHUB, Toulouse, France
- STROMALab, Université de Toulouse, INSERM U1031, EFS, INP-ENVT, UPS, Toulouse, France
| | - Frédéric Bringaud
- Microbiologie Fondamentale et Pathogénicité, UMR 5234, Bordeaux University, CNRS, Bordeaux, France
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536, Bordeaux University, CNRS, Bordeaux, France
- * E-mail:
| |
Collapse
|
5
|
Jakkula P, Narsimulu B, Qureshi IA. Biochemical and structural insights into 6-phosphogluconate dehydrogenase from Leishmania donovani. Appl Microbiol Biotechnol 2021; 105:5471-5489. [PMID: 34250571 DOI: 10.1007/s00253-021-11434-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 05/19/2021] [Accepted: 06/13/2021] [Indexed: 11/29/2022]
Abstract
6-phosphogluconate dehydrogenase (6PGDH) participates in pentose phosphate pathway of glucose metabolism by catalyzing oxidative decarboxylation of 6-phsophogluconate (6PG) and its absence has been lethal for several eukaryotes. Despite being a validated drug target in many organisms like Plasmodium, the enzyme has not been explored in leishmanial parasites. In the present study, 6PGDH of Leishmania donovani (Ld6PGDH) is cloned and purified followed by its characterization using biochemical and structural approaches. Ld6PGDH lacks the glycine-serine-rich sequence at its C-terminal that is present in other eukaryotes including humans. Leishmanial 6PGDH possesses more affinity for substrate (6PG) and cofactor (NADP) in comparison to that of human. The enzymatic activity is inhibited by gentamicin and cefuroxime through competitive mode with functioning more potently towards leishmanial 6PGDH than its human counterpart. CD analysis has shown higher α-helical content in the secondary structure of Ld6PGDH, while fluorescence studies revealed that tryptophan residues are not completely accessible to solvent environment. The three-dimensional structure was generated through homology modelling and docked with substrate and cofactor. The docking studies demonstrated two separate binding pockets for 6PG and NADP with higher affinity for the cofactor binding, and Asn105 is interacting with substrate as well as the cofactor. Additionally, MD simulation has shown complexes of Ld6PGDH with 6PG and NADP to be more stable than its apo form. Altogether, the present study might provide the foundation to investigate this enzyme as potential target against leishmaniasis. KEY POINTS: • Ld6PGDH enzymatic activity is competitively inhibited by gentamicin and cefuroxime. • It displays more helical contents and all structural characteristics of 6PGDH family. • Interaction studies demonstrate higher affinity of cofactor than substrate for Ld6PGDH.
Collapse
Affiliation(s)
- Pranay Jakkula
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao Road, Hyderabad, 500046, India
| | - Bandigi Narsimulu
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao Road, Hyderabad, 500046, India
| | - Insaf Ahmed Qureshi
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao Road, Hyderabad, 500046, India.
| |
Collapse
|
6
|
Study the Mechanism of Antileishmanial Action of Xanthium strumarium Against Amastigotes Stages in Leishmania major: A Metabolomics Approach. Jundishapur J Nat Pharm Prod 2021. [DOI: 10.5812/jjnpp.106431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: Leishmaniasis is among the most important neglected tropical infections, affecting millions of people worldwide. Since 1945, chemotherapy has been the primary treatment for leishmaniasis; however, lengthy and costly treatments associated with various side effects and strains resistant to the conventional therapy have dramatically reduced chemotherapy compounds’ efficacy. Objectives: The antileishmanial activity of the leaf extract of Xanthium strumarium (Asteraceae) was studied. New insights into its mechanism of action toward Leishmania major were provided through a metabolomics-based study. Methods: J774 macrophages were cultured, infected with stationary promastigotes, and treated with different leaf extract concentrations for three days. Antileishmanial activity was assayed by the MTT colorimetric method, and cell metabolites were extracted. 1HNMR spectroscopy was applied, and outliers were analyzed using multivariate statistical analysis. Results: Xanthium strumarium extract (0.15 µg/mL) showed the best activity against L. major amastigotes with the infection rate (IR) and multiplication index (MI) values of 51% and 57%, respectively. The action of X. strumarium extract on amastigotes was comparable with amphotericin B as the positive control (0.015 µg/mL). According to the obtained P-values, pentanoate and coenzyme A biosynthesis, pentose and glucuronate metabolism, valine, leucine and isoleucine biosynthesis, galactose metabolism, amino sugar and nucleotide sugar metabolism were the most important metabolic pathways affected by the plant extract in the amastigote stage of L. major. Conclusions: Our finding demonstrated that X. strumarium leaf extract could be used for discovering and producing novel leishmanicidal medicines. Moreover, the affected metabolic pathways observed in this study could be potential candidates for drug targeting against leishmaniasis.
Collapse
|
7
|
The Trypanosome UDP-Glucose Pyrophosphorylase Is Imported by Piggybacking into Glycosomes, Where Unconventional Sugar Nucleotide Synthesis Takes Place. mBio 2021; 12:e0037521. [PMID: 34044588 PMCID: PMC8262884 DOI: 10.1128/mbio.00375-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Glycosomes are peroxisome-related organelles of trypanosomatid parasites containing metabolic pathways, such as glycolysis and biosynthesis of sugar nucleotides, usually present in the cytosol of other eukaryotes. UDP-glucose pyrophosphorylase (UGP), the enzyme responsible for the synthesis of the sugar nucleotide UDP-glucose, is localized in the cytosol and glycosomes of the bloodstream and procyclic trypanosomes, despite the absence of any known peroxisome-targeting signal (PTS1 and PTS2). The questions that we address here are (i) is the unusual glycosomal biosynthetic pathway of sugar nucleotides functional and (ii) how is the PTS-free UGP imported into glycosomes? We showed that UGP is imported into glycosomes by piggybacking on the glycosomal PTS1-containing phosphoenolpyruvate carboxykinase (PEPCK) and identified the domains involved in the UGP/PEPCK interaction. Proximity ligation assays revealed that this interaction occurs in 3 to 10% of glycosomes, suggesting that these correspond to organelles competent for protein import. We also showed that UGP is essential for the growth of trypanosomes and that both the glycosomal and cytosolic metabolic pathways involving UGP are functional, since the lethality of the knockdown UGP mutant cell line (RNAiUGP, where RNAi indicates RNA interference) was rescued by expressing a recoded UGP (rUGP) in the organelle (RNAiUGP/EXPrUGP-GPDH, where GPDH is glycerol-3-phosphate dehydrogenase). Our conclusion was supported by targeted metabolomic analyses (ion chromatography–high-resolution mass spectrometry [IC-HRMS]) showing that UDP-glucose is no longer detectable in the RNAiUGP mutant, while it is still produced in cells expressing UGP exclusively in the cytosol (PEPCK null mutant) or glycosomes (RNAiUGP/EXPrUGP-GPDH). Trypanosomatids are the only known organisms to have selected functional peroxisomal (glycosomal) sugar nucleotide biosynthetic pathways in addition to the canonical cytosolic ones.
Collapse
|
8
|
Regulation of Fructose 1,6-Bisphosphatase in Procyclic Form Trypanosoma brucei. Pathogens 2021; 10:pathogens10050617. [PMID: 34069826 PMCID: PMC8157246 DOI: 10.3390/pathogens10050617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 01/05/2023] Open
Abstract
Glycolysis is well described in Trypanosoma brucei, while the importance of gluconeogenesis and one of the key enzymes in that pathway, fructose 1,6-bisphosphatase, is less understood. Using a sensitive and specific assay for FBPase, we demonstrate that FBPase activity in insect stage, procyclic form (PF), parasite changes with parasite cell line, extracellular glucose levels, and cell density. FBPase activity in log phase PF 2913 cells was highest in high glucose conditions, where gluconeogenesis is expected to be inactive, and was undetectable in low glucose, where gluconeogenesis is predicted to be active. This unexpected relationship between FBPase activity and extracellular glucose levels suggests that FBPase may not be exclusively involved in gluconeogenesis and may play an additional role in parasite metabolism. In stationary phase cells, the relationship between FBPase activity and extracellular glucose levels was reversed. Furthermore, we found that monomorphic PF 2913 cells had significantly higher FBPase levels than pleomorphic PF AnTat1.1 cells where the activity was undetectable except when cells were grown in standard SDM79 media, which is glucose-rich and commonly used to grow PF trypanosomes in vitro. Finally, we observed several conditions where FBPase activity changed while protein levels did not, suggesting that the enzyme may be regulated via post-translational modifications.
Collapse
|
9
|
Michels PAM, Villafraz O, Pineda E, Alencar MB, Cáceres AJ, Silber AM, Bringaud F. Carbohydrate metabolism in trypanosomatids: New insights revealing novel complexity, diversity and species-unique features. Exp Parasitol 2021; 224:108102. [PMID: 33775649 DOI: 10.1016/j.exppara.2021.108102] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/13/2021] [Accepted: 03/18/2021] [Indexed: 12/16/2022]
Abstract
The human pathogenic trypanosomatid species collectively called the "TriTryp parasites" - Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp. - have complex life cycles, with each of these parasitic protists residing in a different niche during their successive developmental stages where they encounter diverse nutrients. Consequently, they adapt their metabolic network accordingly. Yet, throughout the life cycles, carbohydrate metabolism - involving the glycolytic, gluconeogenic and pentose-phosphate pathways - always plays a central role in the biology of these parasites, whether the available carbon and free energy sources are saccharides, amino acids or lipids. In this paper, we provide an updated review of the carbohydrate metabolism of the TriTryps, highlighting new data about this metabolic network, the interconnection of its pathways and the compartmentalisation of its enzymes within glycosomes, cytosol and mitochondrion. Differences in the expression of the branches of the metabolic network between the successive life-cycle stages of each of these parasitic trypanosomatids are discussed, as well as differences between them. Recent structural and kinetic studies have revealed unique regulatory mechanisms for some of the network's key enzymes with important species-specific variations. Furthermore, reports of multiple post-translational modifications of trypanosomal glycolytic enzymes suggest that additional mechanisms for stage- and/or environmental cues that regulate activity are operational in the parasites. The detailed comparison of the carbohydrate metabolism of the TriTryps has thus revealed multiple differences and a greater complexity, including for the reduced metabolic network in bloodstream-form T. brucei, than previously appreciated. Although these parasites are related, share many cytological and metabolic features and are grouped within a single taxonomic family, the differences highlighted in this review reflect their separate evolutionary tracks from a common ancestor to the extant organisms. These differences are indicative of their adaptation to the different insect vectors and niches occupied in their mammalian hosts.
Collapse
Affiliation(s)
- Paul A M Michels
- Centre for Immunity, Infection and Evolution and Centre for Translational and Chemical Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom.
| | - Oriana Villafraz
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, France
| | - Erika Pineda
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, France
| | - Mayke B Alencar
- Laboratory of Biochemistry of Tryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, 05508-000, Brazil
| | - Ana J Cáceres
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela.
| | - Ariel M Silber
- Laboratory of Biochemistry of Tryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, 05508-000, Brazil.
| | - Frédéric Bringaud
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, France.
| |
Collapse
|
10
|
Du J, Zhu S, Lim RR, Chao JR. Proline metabolism and transport in retinal health and disease. Amino Acids 2021; 53:1789-1806. [PMID: 33871679 PMCID: PMC8054134 DOI: 10.1007/s00726-021-02981-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/10/2021] [Indexed: 12/11/2022]
Abstract
The retina is one of the most energy-demanding tissues in the human body. Photoreceptors in the outer retina rely on nutrient support from the neighboring retinal pigment epithelium (RPE), a monolayer of epithelial cells that separate the retina and choroidal blood supply. RPE dysfunction or cell death can result in photoreceptor degeneration, leading to blindness in retinal degenerative diseases including some inherited retinal degenerations and age-related macular degeneration (AMD). In addition to having ready access to rich nutrients from blood, the RPE is also supplied with lactate from adjacent photoreceptors. Moreover, RPE can phagocytose lipid-rich outer segments for degradation and recycling on a daily basis. Recent studies show RPE cells prefer proline as a major metabolic substrate, and they are highly enriched for the proline transporter, SLC6A20. In contrast, dysfunctional or poorly differentiated RPE fails to utilize proline. RPE uses proline to fuel mitochondrial metabolism, synthesize amino acids, build the extracellular matrix, fight against oxidative stress, and sustain differentiation. Remarkably, the neural retina rarely imports proline directly, but it uptakes and utilizes intermediates and amino acids derived from proline catabolism in the RPE. Mutations of genes in proline metabolism are associated with retinal degenerative diseases, and proline supplementation is reported to improve RPE-initiated vision loss. This review will cover proline metabolism in RPE and highlight the importance of proline transport and utilization in maintaining retinal metabolism and health.
Collapse
Affiliation(s)
- Jianhai Du
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV, 26506, USA. .,Department of Biochemistry, West Virginia University, Morgantown, WV, 26506, USA. .,One Medical Center Dr, WVU Eye Institute, PO Box 9193, Morgantown, WV, 26505, USA.
| | - Siyan Zhu
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV, 26506, USA.,Department of Biochemistry, West Virginia University, Morgantown, WV, 26506, USA
| | - Rayne R Lim
- Department of Ophthalmology, University of Washington, Seattle, WA, 98109, USA
| | - Jennifer R Chao
- Department of Ophthalmology, University of Washington, Seattle, WA, 98109, USA
| |
Collapse
|
11
|
Wargnies M, Plazolles N, Schenk R, Villafraz O, Dupuy JW, Biran M, Bachmaier S, Baudouin H, Clayton C, Boshart M, Bringaud F. Metabolic selection of a homologous recombination-mediated gene loss protects Trypanosoma brucei from ROS production by glycosomal fumarate reductase. J Biol Chem 2021; 296:100548. [PMID: 33741344 PMCID: PMC8065229 DOI: 10.1016/j.jbc.2021.100548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 03/08/2021] [Accepted: 03/15/2021] [Indexed: 11/23/2022] Open
Abstract
The genome of trypanosomatids rearranges by using repeated sequences as platforms for amplification or deletion of genomic segments. These stochastic recombination events have a direct impact on gene dosage and foster the selection of adaptive traits in response to environmental pressure. We provide here such an example by showing that the phosphoenolpyruvate carboxykinase (PEPCK) gene knockout (Δpepck) leads to the selection of a deletion event between two tandemly arranged fumarate reductase (FRDg and FRDm2) genes to produce a chimeric FRDg-m2 gene in the Δpepck∗ cell line. FRDg is expressed in peroxisome-related organelles, named glycosomes, expression of FRDm2 has not been detected to date, and FRDg-m2 is nonfunctional and cytosolic. Re-expression of FRDg significantly impaired growth of the Δpepck∗ cells, but FRD enzyme activity was not required for this negative effect. Instead, glycosomal localization as well as the covalent flavinylation motif of FRD is required to confer growth retardation and intracellular accumulation of reactive oxygen species (ROS). The data suggest that FRDg, similar to Escherichia coli FRD, can generate ROS in a flavin-dependent process by transfer of electrons from NADH to molecular oxygen instead of fumarate when the latter is unavailable, as in the Δpepck background. Hence, growth retardation is interpreted as a consequence of increased production of ROS, and rearrangement of the FRD locus liberates Δpepck∗ cells from this obstacle. Interestingly, intracellular production of ROS has been shown to be required to complete the parasitic cycle in the insect vector, suggesting that FRDg may play a role in this process.
Collapse
Affiliation(s)
- Marion Wargnies
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Bordeaux, France; Univ. Bordeaux, CNRS, Centre de Résonance Magnétique des Systèmes Biologiques (CRMSB), UMR 5536, Bordeaux, France
| | - Nicolas Plazolles
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Bordeaux, France
| | - Robin Schenk
- Fakultät für Biologie, Genetik, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Oriana Villafraz
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Bordeaux, France
| | | | - Marc Biran
- Univ. Bordeaux, CNRS, Centre de Résonance Magnétique des Systèmes Biologiques (CRMSB), UMR 5536, Bordeaux, France
| | - Sabine Bachmaier
- Fakultät für Biologie, Genetik, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Hélène Baudouin
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Bordeaux, France; Univ. Bordeaux, CNRS, Centre de Résonance Magnétique des Systèmes Biologiques (CRMSB), UMR 5536, Bordeaux, France
| | - Christine Clayton
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZBMH), Universität Heidelberg, Heidelberg, Germany
| | - Michael Boshart
- Fakultät für Biologie, Genetik, Ludwig-Maximilians-Universität München, Martinsried, Germany.
| | - Frédéric Bringaud
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Bordeaux, France; Univ. Bordeaux, CNRS, Centre de Résonance Magnétique des Systèmes Biologiques (CRMSB), UMR 5536, Bordeaux, France.
| |
Collapse
|
12
|
Identification of positive and negative regulators in the stepwise developmental progression towards infectivity in Trypanosoma brucei. Sci Rep 2021; 11:5755. [PMID: 33707699 PMCID: PMC7952579 DOI: 10.1038/s41598-021-85225-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/25/2021] [Indexed: 11/17/2022] Open
Abstract
Trypanosoma brucei is a protozoan parasite that causes important human and livestock diseases in sub-Saharan Africa. By overexpressing a single RNA-binding protein, RBP6, in non-infectious procyclics trypanosomes, we previously recapitulated in vitro the events occurring in the tsetse fly vector, namely the development of epimastigotes and infectious, quiescent metacyclic parasites. To identify genes involved in this developmental progression, we individually targeted 86 transcripts by RNAi in the RBP6 overexpression cell line and assessed the loss-of-function phenotypes on repositioning the kinetoplast, an organelle that contains the mitochondrial genome, the expression of BARP or brucei alanine rich protein, a marker for epimastigotes, and metacyclic variant surface glycoprotein. This screen identified 22 genes that positively or negatively regulate the stepwise progression towards infectivity at different stages. Two previously uncharacterized putative nucleic acid binding proteins emerged as potent regulators, namely the cold shock domain-containing proteins CSD1 and CSD2. RNA-Seq data from a selected group of cell lines further revealed that the components of gene expression regulatory networks identified in this study affected the abundance of a subset of transcripts in very similar fashion. Finally, our data suggest a considerable overlap between the genes that regulate the formation of stumpy bloodstream form trypanosomes and the genes that govern the development of metacyclic form parasites.
Collapse
|
13
|
Villafraz O, Biran M, Pineda E, Plazolles N, Cahoreau E, Ornitz Oliveira Souza R, Thonnus M, Allmann S, Tetaud E, Rivière L, Silber AM, Barrett MP, Zíková A, Boshart M, Portais JC, Bringaud F. Procyclic trypanosomes recycle glucose catabolites and TCA cycle intermediates to stimulate growth in the presence of physiological amounts of proline. PLoS Pathog 2021; 17:e1009204. [PMID: 33647053 PMCID: PMC7951978 DOI: 10.1371/journal.ppat.1009204] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 03/11/2021] [Accepted: 02/09/2021] [Indexed: 12/18/2022] Open
Abstract
Trypanosoma brucei, a protist responsible for human African trypanosomiasis (sleeping sickness), is transmitted by the tsetse fly where the procyclic forms of the parasite develop in the proline-rich (1–2 mM) and glucose-depleted digestive tract. Proline is essential for the midgut colonization of the parasite in the insect vector, however other carbon sources could be available and used to feed its central metabolism. Here we show that procyclic trypanosomes can consume and metabolize metabolic intermediates, including those excreted from glucose catabolism (succinate, alanine and pyruvate), with the exception of acetate, which is the ultimate end-product excreted by the parasite. Among the tested metabolites, tricarboxylic acid (TCA) cycle intermediates (succinate, malate and α-ketoglutarate) stimulated growth of the parasite in the presence of 2 mM proline. The pathways used for their metabolism were mapped by proton-NMR metabolic profiling and phenotypic analyses of thirteen RNAi and/or null mutants affecting central carbon metabolism. We showed that (i) malate is converted to succinate by both the reducing and oxidative branches of the TCA cycle, which demonstrates that procyclic trypanosomes can use the full TCA cycle, (ii) the enormous rate of α-ketoglutarate consumption (15-times higher than glucose) is possible thanks to the balanced production and consumption of NADH at the substrate level and (iii) α-ketoglutarate is toxic for trypanosomes if not appropriately metabolized as observed for an α-ketoglutarate dehydrogenase null mutant. In addition, epimastigotes produced from procyclics upon overexpression of RBP6 showed a growth defect in the presence of 2 mM proline, which is rescued by α-ketoglutarate, suggesting that physiological amounts of proline are not sufficient per se for the development of trypanosomes in the fly. In conclusion, these data show that trypanosomes can metabolize multiple metabolites, in addition to proline, which allows them to confront challenging environments in the fly. In the midgut of its insect vector, trypanosomes rely on proline to feed their energy metabolism. However, the availability of other potential carbon sources that can be used by the parasite is currently unknown. Here we show that tricarboxylic acid (TCA) cycle intermediates, i.e. succinate, malate and α-ketoglutarate, stimulate growth of procyclic trypanosomes incubated in a medium containing 2 mM proline, which is in the range of the amounts measured in the midgut of the fly. Some of these additional carbon sources are needed for the development of epimastigotes, which differentiate from procyclics in the midgut of the fly, since their growth defect observed in the presence of 2 mM proline is rescued by addition of α-ketoglutarate. In addition, we have implemented new approaches to study a poorly explored branch of the TCA cycle converting malate to α-ketoglutarate, which was previously described as non-functional in the parasite, regardless of the glucose levels available. The discovery of this branch reveals that a full TCA cycle can operate in procyclic trypanosomes. Our data broaden the metabolic potential of trypanosomes and pave the way for a better understanding of the parasite’s metabolism in various organ systems of the tsetse fly, where it develops.
Collapse
Affiliation(s)
- Oriana Villafraz
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Bordeaux, France
| | - Marc Biran
- Univ. Bordeaux, CNRS, Centre de Résonance Magnétique des Systèmes Biologiques (CRMSB), UMR 5536, Bordeaux, France
| | - Erika Pineda
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Bordeaux, France
| | - Nicolas Plazolles
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Bordeaux, France
| | - Edern Cahoreau
- Toulouse Biotechnology Institute, TBI-INSA de Toulouse INSA/CNRS 5504-UMR INSA/INRA 792, Toulouse, France.,MetaToul-MetaboHub, National Infrastructure of Metabolomics and Fluxomics, Toulouse, France
| | - Rodolpho Ornitz Oliveira Souza
- Laboratory of Biochemistry of Tryps-LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Magali Thonnus
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Bordeaux, France
| | - Stefan Allmann
- Fakultät für Biologie, Genetik, Ludwig-Maximilians-Universität München, Grosshadernerstrasse 2-4, Martinsried, Germany
| | - Emmanuel Tetaud
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Bordeaux, France
| | - Loïc Rivière
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Bordeaux, France
| | - Ariel M Silber
- Laboratory of Biochemistry of Tryps-LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Michael P Barrett
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.,Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, Garscube Campus, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Alena Zíková
- Institute of Parasitology, Biology Center, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Michael Boshart
- Fakultät für Biologie, Genetik, Ludwig-Maximilians-Universität München, Grosshadernerstrasse 2-4, Martinsried, Germany
| | - Jean-Charles Portais
- Toulouse Biotechnology Institute, TBI-INSA de Toulouse INSA/CNRS 5504-UMR INSA/INRA 792, Toulouse, France.,MetaToul-MetaboHub, National Infrastructure of Metabolomics and Fluxomics, Toulouse, France.,RESTORE, Université de Toulouse, Inserm U1031, CNRS 5070, UPS, EFS, ENVT, Toulouse, France
| | - Frédéric Bringaud
- Univ. Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Bordeaux, France
| |
Collapse
|
14
|
Mondal DK, Pal DS, Abbasi M, Datta R. Functional partnership between carbonic anhydrase and malic enzyme in promoting gluconeogenesis in
Leishmania major. FEBS J 2021; 288:4129-4152. [DOI: 10.1111/febs.15720] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 11/29/2020] [Accepted: 01/15/2021] [Indexed: 12/24/2022]
Affiliation(s)
- Dipon Kumar Mondal
- Department of Biological Sciences Indian Institute of Science Education and Research (IISER) Kolkata Mohanpur India
| | - Dhiman Sankar Pal
- Department of Biological Sciences Indian Institute of Science Education and Research (IISER) Kolkata Mohanpur India
| | - Mazharul Abbasi
- Department of Biological Sciences Indian Institute of Science Education and Research (IISER) Kolkata Mohanpur India
| | - Rupak Datta
- Department of Biological Sciences Indian Institute of Science Education and Research (IISER) Kolkata Mohanpur India
| |
Collapse
|
15
|
Ortíz C, Moraca F, Laverriere M, Jordan A, Hamilton N, Comini MA. Glucose 6-Phosphate Dehydrogenase from Trypanosomes: Selectivity for Steroids and Chemical Validation in Bloodstream Trypanosoma brucei. Molecules 2021; 26:E358. [PMID: 33445584 PMCID: PMC7826790 DOI: 10.3390/molecules26020358] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 01/07/2021] [Accepted: 01/09/2021] [Indexed: 11/17/2022] Open
Abstract
Glucose 6-phosphate dehydrogenase (G6PDH) fulfills an essential role in cell physiology by catalyzing the production of NADPH+ and of a precursor for the de novo synthesis of ribose 5-phosphate. In trypanosomatids, G6PDH is essential for in vitro proliferation, antioxidant defense and, thereby, drug resistance mechanisms. So far, 16α-brominated epiandrosterone represents the most potent hit targeting trypanosomal G6PDH. Here, we extended the investigations on this important drug target and its inhibition by using a small subset of androstane derivatives. In Trypanosoma cruzi, immunofluorescence revealed a cytoplasmic distribution of G6PDH and the absence of signal in major organelles. Cytochemical assays confirmed parasitic G6PDH as the molecular target of epiandrosterone. Structure-activity analysis for a set of new (dehydro)epiandrosterone derivatives revealed that bromination at position 16α of the cyclopentane moiety yielded more potent T. cruzi G6PDH inhibitors than the corresponding β-substituted analogues. For the 16α brominated compounds, the inclusion of an acetoxy group at position 3 either proved detrimental or enhanced the activity of the epiandrosterone or the dehydroepiandrosterone derivatives, respectively. Most derivatives presented single digit μM EC50 against infective T. brucei and the killing mechanism involved an early thiol-redox unbalance. This data suggests that infective African trypanosomes lack efficient NADPH+-synthesizing pathways, beyond the Pentose Phosphate, to maintain thiol-redox homeostasis.
Collapse
Affiliation(s)
- Cecilia Ortíz
- Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo 11400, Uruguay;
| | - Francesca Moraca
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Via Aldo Moro 2, 53100 Siena, Italy;
| | - Marc Laverriere
- Instituto de Investigaciones Biotecnológicas, Instituto Tecnológico de Chascomus (IIB-INTECH, UNSAM-CONICET), Av. General Paz 5445, INTI, San Martín 1650, Pcia de Buenos Aires, Argentina;
| | - Allan Jordan
- Drug Discovery Unit, Cancer Research UK Manchester Institute, University of Manchester, Alderley Park, Macclesfield SK10 4TG, UK; (A.J.); (N.H.)
| | - Niall Hamilton
- Drug Discovery Unit, Cancer Research UK Manchester Institute, University of Manchester, Alderley Park, Macclesfield SK10 4TG, UK; (A.J.); (N.H.)
| | - Marcelo A. Comini
- Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo 11400, Uruguay;
| |
Collapse
|
16
|
Hysteresis of pyruvate phosphate dikinase from Trypanosoma cruzi. Parasitol Res 2020; 120:1421-1428. [PMID: 33098461 DOI: 10.1007/s00436-020-06934-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 10/13/2020] [Indexed: 10/23/2022]
Abstract
Trypanosoma cruzi, the causative agent of Chagas' disease, belongs to the Trypanosomatidae family. The parasite undergoes multiple morphological and metabolic changes during its life cycle, in which it can use both glucose and amino acids as carbon and energy sources. The glycolytic pathway is peculiar in that its first six or seven steps are compartmentalized in glycosomes, and has a two-branched auxiliary glycosomal system functioning beyond the intermediate phosphoenolpyruvate (PEP) that is also used in the cytosol as substrate by pyruvate kinase. The pyruvate phosphate dikinase (PPDK) is the first enzyme of one branch, converting PEP, PPi, and AMP into pyruvate, Pi, and ATP. Here we present a kinetic study of PPDK from T. cruzi that reveals its hysteretic behavior. The length of the lag phase, and therefore the time for reaching higher specific activity values is affected by the concentration of the enzyme, the presence of hydrogen ions and the concentrations of the enzyme's substrates. Additionally, the formation of a more active PPDK with more complex structure is promoted by it substrates and the cation ammonium, indicating that this enzyme equilibrates between the monomeric (less active) and a more complex (more active) form depending on the medium. These results confirm the hysteretic behavior of PPDK and are suggestive for its functioning as a regulatory mechanism of this auxiliary pathway. Such a regulation could serve to distribute the glycolytic flux over the two auxiliary branches as a response to the different environments that the parasite encounters during its life cycle.
Collapse
|
17
|
Škodová-Sveráková I, Prokopchuk G, Peña-Diaz P, Záhonová K, Moos M, Horváth A, Šimek P, Lukeš J. Unique Dynamics of Paramylon Storage in the Marine Euglenozoan Diplonema papillatum. Protist 2020; 171:125717. [PMID: 32087573 DOI: 10.1016/j.protis.2020.125717] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 01/07/2020] [Accepted: 02/02/2020] [Indexed: 10/25/2022]
Abstract
Diplonemids belong to the most diverse and abundant marine protists, which places them among the key players of the oceanic ecosystem. Under in vitro conditions, their best-known representative Diplonema papillatum accumulates in its cytoplasm a crystalline polymer. When grown under the nutrient-poor conditions, but not nutrient-rich conditions, D. papillatum synthesizes a β-1,3-glucan polymer, also known as paramylon. This phenomenon is unexpected, as it is in striking contrast to the accumulation of paramylon in euglenids, since these related flagellates synthesize this polymer solely under nutrient-rich conditions. The capacity of D. papillatum to store an energy source in the form of polysaccharides when the environment is poor in nutrients is unexpected and may contribute to the wide distribution of these protists in the ocean.
Collapse
Affiliation(s)
- Ingrid Škodová-Sveráková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic; Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Galina Prokopchuk
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
| | - Priscila Peña-Diaz
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic; Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Kristína Záhonová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic; Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Martin Moos
- Institute of Entomology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
| | - Anton Horváth
- Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Petr Šimek
- Institute of Entomology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic.
| |
Collapse
|
18
|
Yu HF, Duan CC, Yang ZQ, Wang YS, Yue ZP, Guo B. Malic enzyme 1 is important for uterine decidualization in response to progesterone/cAMP/PKA/HB-EGF pathway. FASEB J 2020; 34:3820-3837. [PMID: 31944402 DOI: 10.1096/fj.201902289r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 12/12/2019] [Accepted: 12/21/2019] [Indexed: 01/17/2023]
Abstract
Malic enzyme 1 (Me1), a member of the malic enzymes involving in glycolytic pathway and citric acid cycle, is essential for the energy metabolism and maintenance of intracellular redox balance state, but its physiological role and regulatory mechanism in the uterine decidualization are still unknown. Current study showed that Me1 was strongly expressed in decidual cells, and could promote the proliferation and differentiation of stromal cells followed by an accelerated cell cycle transition, indicating an importance of Me1 in the uterine decidualization. Silencing of Me1 attenuated NADPH generation and reduced GR activity, while addition of NADPH improved the defect of GR activity elicited by Me1 depletion. Further analysis found that Me1 modulated intracellular GSH content via GR. Meanwhile, Me1 played a role in maintaining mitochondrial function as indicated by these observations that blockadge of Me1 led to the accumulation of mitochondrial O 2 - level and decreased ATP production and mtDNA copy numbers accompanied with defective mitochondrial membrane potential. In uterine stromal cells, progesterone induced Me1 expression through PR-cAMP-PKA pathway. Knockdown of HB-EGF might impede the regulation of progesterone and cAMP on Me1. Collectively, Me1 is essential for uterine decidualization in response to progesterone/cAMP/PKA/HB-EGF pathway and plays an important role in preventing mitochondrial dysfunction.
Collapse
Affiliation(s)
- Hai-Fan Yu
- College of Veterinary Medicine, Jilin University, Changchun, P. R. China
| | - Cui-Cui Duan
- Institute of Agro-food Technology, Jilin Academy of Agricultural Sciences, Changchun, P. R. China
| | - Zhan-Qing Yang
- College of Veterinary Medicine, Jilin University, Changchun, P. R. China
| | - Yu-Si Wang
- College of Veterinary Medicine, Jilin University, Changchun, P. R. China
| | - Zhan-Peng Yue
- College of Veterinary Medicine, Jilin University, Changchun, P. R. China
| | - Bin Guo
- College of Veterinary Medicine, Jilin University, Changchun, P. R. China
| |
Collapse
|
19
|
Cordeiro AT. NADPH Producing Enzymes as Promising Drug Targets for Chagas Disease. Curr Med Chem 2019; 26:6564-6571. [PMID: 30306853 DOI: 10.2174/0929867325666181009152844] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 09/10/2018] [Accepted: 09/19/2018] [Indexed: 11/22/2022]
Abstract
Reduced Nicotinamide Adenine Dinucleotide Phosphate (NADPH) is a cofactor used in different anabolic reactions, such as lipid and nucleic acid synthesis, and for oxidative stress defense. NADPH is essential for parasite growth and viability. In trypanosomatid parasites, NADPH is supplied by the oxidative branch of the pentose phosphate pathway and by enzymes associated with the citric acid cycle. The present article will review recent achievements that suggest glucose-6-phosphate dehydrogenase and the cytosolic isoform of the malic enzyme as promising drug targets for the discovery of new drugs against Trypanosoma cruzi and T. brucei. Topics involving an alternative strategy in accelerating T. cruzi drug-target validation and the concept of drug-target classification will also be revisited.
Collapse
Affiliation(s)
- Artur T Cordeiro
- Brazilian Bioscience National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas- SP, Brazil
| |
Collapse
|
20
|
Liu B, Kamanyi Marucha K, Clayton C. The zinc finger proteins ZC3H20 and ZC3H21 stabilise mRNAs encoding membrane proteins and mitochondrial proteins in insect-form Trypanosoma brucei. Mol Microbiol 2019; 113:430-451. [PMID: 31743541 DOI: 10.1111/mmi.14429] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 10/24/2019] [Accepted: 11/17/2019] [Indexed: 12/26/2022]
Abstract
ZC3H20 and ZC3H21 are related trypanosome proteins with two C(x)8 C(x)5 C(x)3 H zinc finger motifs. ZC3H20 is present at a low level in replicating mammalian-infective bloodstream forms, but becomes more abundant when they undergo growth arrest at high density; ZC3H21 appears only in the procyclic form of the parasite, which infects Tsetse flies. Each protein binds to several hundred mRNAs, with overlapping but not identical specificities. Both increase expression of bound mRNAs, probably through recruitment of the MKT1-PBP1 complex. At least 28 of the bound mRNAs decrease after depletion of ZC3H20, or of ZC3H20 and ZC3H21 together; their products include procyclic-specific proteins of the plasma membrane and energy metabolism. Simultaneous depletion of ZC3H20 and ZC3H21 causes procyclic forms to shrink and stop growing; in addition to decreases in target mRNAs, there are other changes suggestive of loss of developmental regulation. The bloodstream-form-specific protein RBP10 controls ZC3H20 and ZC3H21 expression. Interestingly, some ZC3H20/21 target mRNAs also bind to and are repressed by RBP10, allowing for dynamic regulation as RBP10 decreases and ZC3H20 and ZC3H21 increase during differentiation.
Collapse
Affiliation(s)
- Bin Liu
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Kevin Kamanyi Marucha
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Christine Clayton
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| |
Collapse
|
21
|
Yam M, Engel AL, Wang Y, Zhu S, Hauer A, Zhang R, Lohner D, Huang J, Dinterman M, Zhao C, Chao JR, Du J. Proline mediates metabolic communication between retinal pigment epithelial cells and the retina. J Biol Chem 2019; 294:10278-10289. [PMID: 31110046 PMCID: PMC6664195 DOI: 10.1074/jbc.ra119.007983] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 05/16/2019] [Indexed: 01/16/2023] Open
Abstract
The retinal pigment epithelium (RPE) is a monolayer of pigmented cells between the choroid and the retina. RPE dysfunction underlies many retinal degenerative diseases, including age-related macular degeneration, the leading cause of age-related blindness. To perform its various functions in nutrient transport, phagocytosis of the outer segment, and cytokine secretion, the RPE relies on an active energy metabolism. We previously reported that human RPE cells prefer proline as a nutrient and transport proline-derived metabolites to the apical, or retinal, side. In this study, we investigated how RPE utilizes proline in vivo and why proline is a preferred substrate. By using [13C]proline labeling both ex vivo and in vivo, we found that the retina rarely uses proline directly, whereas the RPE utilizes it at a high rate, exporting proline-derived mitochondrial intermediates for use by the retina. We observed that in primary human RPE cell culture, proline is the only amino acid whose uptake increases with cellular maturity. In human RPE, proline was sufficient to stimulate de novo serine synthesis, increase reductive carboxylation, and protect against oxidative damage. Blocking proline catabolism in RPE impaired glucose metabolism and GSH production. Notably, in an acute model of RPE-induced retinal degeneration, dietary proline improved visual function. In conclusion, proline is an important nutrient that supports RPE metabolism and the metabolic demand of the retina.
Collapse
Affiliation(s)
- Michelle Yam
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Abbi L Engel
- the Department of Ophthalmology, University of Washington, Seattle, Washington 98109
| | - Yekai Wang
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Siyan Zhu
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Allison Hauer
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Rui Zhang
- From the Departments of Ophthalmology and
- the Save Sight Institute, University of Sydney, 8 Macquarie Street, Sydney, New South Wales 2000, Australia
| | - Daniel Lohner
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Jiancheng Huang
- From the Departments of Ophthalmology and
- the Eye Institute, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China, and
- the Department of Ophthalmology, State Key Laboratory of Reproductive Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | - Marlee Dinterman
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| | - Chen Zhao
- the Eye Institute, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China, and
| | - Jennifer R Chao
- the Department of Ophthalmology, University of Washington, Seattle, Washington 98109,
| | - Jianhai Du
- From the Departments of Ophthalmology and
- Biochemistry, West Virginia University, Morgantown, West Virginia 26506
| |
Collapse
|
22
|
Piacenza L, Trujillo M, Radi R. Reactive species and pathogen antioxidant networks during phagocytosis. J Exp Med 2019; 216:501-516. [PMID: 30792185 PMCID: PMC6400530 DOI: 10.1084/jem.20181886] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/04/2019] [Accepted: 02/04/2019] [Indexed: 11/23/2022] Open
Abstract
This review discusses the generation of phagosomal cytotoxic reactive species by activated macrophages and neutrophils for the control of intracellular pathogens, and the mechanisms by which microbes combat host-derived oxidants via antioxidant networks that mitigate the redox-dependent control of infection. The generation of phagosomal cytotoxic reactive species (i.e., free radicals and oxidants) by activated macrophages and neutrophils is a crucial process for the control of intracellular pathogens. The chemical nature of these species, the reactions they are involved in, and the subsequent effects are multifaceted and depend on several host- and pathogen-derived factors that influence their production rates and catabolism inside the phagosome. Pathogens rely on an intricate and synergistic antioxidant armamentarium that ensures their own survival by detoxifying reactive species. In this review, we discuss the generation, kinetics, and toxicity of reactive species generated in phagocytes, with a focus on the response of macrophages to internalized pathogens and concentrating on Mycobacterium tuberculosis and Trypanosoma cruzi as examples of bacterial and parasitic infection, respectively. The ability of pathogens to deal with host-derived reactive species largely depends on the competence of their antioxidant networks at the onset of invasion, which in turn can tilt the balance toward pathogen survival, proliferation, and virulence over redox-dependent control of infection.
Collapse
Affiliation(s)
- Lucía Piacenza
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.,Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Madia Trujillo
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.,Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Rafael Radi
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay .,Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| |
Collapse
|
23
|
Gluconeogenesis is essential for trypanosome development in the tsetse fly vector. PLoS Pathog 2018; 14:e1007502. [PMID: 30557412 PMCID: PMC6312356 DOI: 10.1371/journal.ppat.1007502] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 12/31/2018] [Accepted: 12/04/2018] [Indexed: 11/19/2022] Open
Abstract
In the glucose-free environment that is the midgut of the tsetse fly vector, the procyclic form of Trypanosoma brucei primarily uses proline to feed its central carbon and energy metabolism. In these conditions, the parasite needs to produce glucose 6-phosphate (G6P) through gluconeogenesis from metabolism of non-glycolytic carbon source(s). We showed here that two phosphoenolpyruvate-producing enzymes, PEP carboxykinase (PEPCK) and pyruvate phosphate dikinase (PPDK) have a redundant function for the essential gluconeogenesis from proline. Indeed, incorporation of 13C-enriched proline into G6P was abolished in the PEPCK/PPDK null double mutant (Δppdk/Δpepck), but not in the single Δppdk and Δpepck mutant cell lines. The procyclic trypanosome also uses the glycerol conversion pathway to feed gluconeogenesis, since the death of the Δppdk/Δpepck double null mutant in glucose-free conditions is only observed after RNAi-mediated down-regulation of the expression of the glycerol kinase, the first enzyme of the glycerol conversion pathways. Deletion of the gene encoding fructose-1,6-bisphosphatase (Δfbpase), a key gluconeogenic enzyme irreversibly producing fructose 6-phosphate from fructose 1,6-bisphosphate, considerably reduced, but not abolished, incorporation of 13C-enriched proline into G6P. In addition, the Δfbpase cell line is viable in glucose-free conditions, suggesting that an alternative pathway can be used for G6P production in vitro. However, FBPase is essential in vivo, as shown by the incapacity of the Δfbpase null mutant to colonise the fly vector salivary glands, while the parental phenotype is restored in the Δfbpase rescued cell line re-expressing FBPase. The essential role of FBPase for the development of T. brucei in the tsetse was confirmed by taking advantage of an in vitro differentiation assay based on the RNA-binding protein 6 over-expression, in which the procyclic forms differentiate into epimastigote forms but not into mammalian-infective metacyclic parasites. In total, morphology, immunofluorescence and cytometry analyses showed that the differentiation of the epimastigote stages into the metacyclic forms is abolished in the Δfbpase mutant.
Collapse
|
24
|
Kovářová J, Nagar R, Faria J, Ferguson MAJ, Barrett MP, Horn D. Gluconeogenesis using glycerol as a substrate in bloodstream-form Trypanosoma brucei. PLoS Pathog 2018; 14:e1007475. [PMID: 30589893 PMCID: PMC6307712 DOI: 10.1371/journal.ppat.1007475] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 11/19/2018] [Indexed: 12/20/2022] Open
Abstract
Bloodstream form African trypanosomes are thought to rely exclusively upon glycolysis, using glucose as a substrate, for ATP production. Indeed, the pathway has long been considered a potential therapeutic target to tackle the devastating and neglected tropical diseases caused by these parasites. However, plasma membrane glucose and glycerol transporters are both expressed by trypanosomes and these parasites can infiltrate tissues that contain glycerol. Here, we show that bloodstream form trypanosomes can use glycerol for gluconeogenesis and for ATP production, particularly when deprived of glucose following hexose transporter depletion. We demonstrate that Trypanosoma brucei hexose transporters 1 and 2 (THT1 and THT2) are localized to the plasma membrane and that knockdown of THT1 expression leads to a growth defect that is more severe when THT2 is also knocked down. These data are consistent with THT1 and THT2 being the primary routes of glucose supply for the production of ATP by glycolysis. However, supplementation of the growth medium with glycerol substantially rescued the growth defect caused by THT1 and THT2 knockdown. Metabolomic analyses with heavy-isotope labelled glycerol demonstrated that trypanosomes take up glycerol and use it to synthesize intermediates of gluconeogenesis, including fructose 1,6-bisphosphate and hexose 6-phosphates, which feed the pentose phosphate pathway and variant surface glycoprotein biosynthesis. We used Cas9-mediated gene knockout to demonstrate a gluconeogenesis-specific, but fructose-1,6-bisphosphatase (Tb927.9.8720)-independent activity, converting fructose 1,6-bisphosphate into fructose 6-phosphate. In addition, we observed increased flux through the tricarboxylic acid cycle and the succinate shunt. Thus, contrary to prior thinking, gluconeogenesis can operate in bloodstream form T. brucei. This pathway, using glycerol as a physiological substrate, may be required in mammalian host tissues.
Collapse
Affiliation(s)
- Julie Kovářová
- The Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee, United Kingdom
| | - Rupa Nagar
- The Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee, United Kingdom
| | - Joana Faria
- The Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee, United Kingdom
| | - Michael A. J. Ferguson
- The Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee, United Kingdom
| | - Michael P. Barrett
- The Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, United Kingdom
- Glasgow Polyomics, University of Glasgow, Glasgow, United Kingdom
| | - David Horn
- The Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee, United Kingdom
| |
Collapse
|
25
|
Clayton C. Novel Observations Concerning Differentiation of Bloodstream-Form Trypanosomes to the Form That Is Adapted for Growth in Tsetse Flies. mSphere 2018; 3:e00533-18. [PMID: 30381355 PMCID: PMC6211223 DOI: 10.1128/msphere.00533-18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Salivarian trypanosomes grow in mammals, where they depend on glucose, and as procyclic forms in tsetse flies, where they metabolize proline. Differentiation of bloodstream forms to nongrowing stumpy forms, and to procyclic forms, has been studied extensively, but reconciling the results is tricky because investigators have used parasites with various differentiation competences and different media for procyclic-form culture. Standard protocols include lowering the temperature to 27°C, adding a tricarboxylic acid, and transferring the parasites to high-proline medium, often including glucose. A 20°C cold shock enhanced efficiency. Y. Qiu, J. E. Milanes, J. A. Jones, R. E. Noorai, et al. (mSphere 3:e00366-18, 2018, https://doi.org/10.1128/mSphere.00366-18) studied this systematically, and their results call long-established protocols into question. Importantly, highly efficient differentiation was observed after cold shock and transfer to no-glucose medium without tricarboxylic acid; in contrast, glucose made differentiation tricarboxylic acid dependent and inhibited procyclic growth. New transcriptome data for stumpy and procyclic forms will enable informative comparisons with biochemical observations and with other RNA and protein data sets.
Collapse
Affiliation(s)
- Christine Clayton
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| |
Collapse
|
26
|
Mota SGR, Mercaldi GF, Pereira JGC, Oliveira PSL, Rodriguez A, Cordeiro AT. First Nonphosphorylated Inhibitors of Phosphoglucose Isomerase Identified by Chemical Library Screening. SLAS DISCOVERY 2018; 23:1051-1059. [PMID: 29995453 DOI: 10.1177/2472555218787468] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Human African trypanosomiasis, Chagas disease, and leishmaniasis are human infections caused by kinetoplastid parasites of the genera Trypanosoma and Leishmania. Besides their severity and global impact, treatments are still challenging. Currently available drugs have important limitations, highlighting the urgent need to develop new drugs. Phosphoglucose isomerase (PGI) is considered a promising target for the development of antiparasitic drugs, as it acts on two essential metabolic pathways, glycolysis and gluconeogenesis. Herein, we describe the identification of new nonphosphorylated inhibitors of Leishmania mexicana PGI ( LmPGI), with the potential for the development of antiparasitic drugs. A fluorescence-based high-throughput screening (HTS) assay was developed by coupling the activities of recombinant LmPGI with glucose-6-phosphate dehydrogenase and diaphorase. This coupled assay was used to screen 42,720 compounds from ChemBridge and TimTec commercial libraries. After confirmatory assays, selected LmPGI inhibitors were tested against homologous Trypanosoma cruzi and humans. The PGI hits are effective against trypanosomatid PGIs, with IC50 values in the micromolar range, and also against the human homologous enzyme. A computational analysis of cavities present on PGI's crystallographic structure suggests a potential binding site for the proposed mixed-type inhibition mechanism.
Collapse
Affiliation(s)
- Sabrina G R Mota
- 1 Brazilian Bioscience National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil.,2 Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | - Gustavo F Mercaldi
- 1 Brazilian Bioscience National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| | - José G C Pereira
- 1 Brazilian Bioscience National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| | - Paulo S L Oliveira
- 1 Brazilian Bioscience National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| | - Ana Rodriguez
- 3 New York University School of Medicine, Department of Microbiology, New York, NY, USA
| | - Artur T Cordeiro
- 1 Brazilian Bioscience National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, SP, Brazil
| |
Collapse
|
27
|
Millerioux Y, Mazet M, Bouyssou G, Allmann S, Kiema TR, Bertiaux E, Fouillen L, Thapa C, Biran M, Plazolles N, Dittrich-Domergue F, Crouzols A, Wierenga RK, Rotureau B, Moreau P, Bringaud F. De novo biosynthesis of sterols and fatty acids in the Trypanosoma brucei procyclic form: Carbon source preferences and metabolic flux redistributions. PLoS Pathog 2018; 14:e1007116. [PMID: 29813135 PMCID: PMC5993337 DOI: 10.1371/journal.ppat.1007116] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 06/08/2018] [Accepted: 05/22/2018] [Indexed: 12/27/2022] Open
Abstract
De novo biosynthesis of lipids is essential for Trypanosoma brucei, a protist responsible for the sleeping sickness. Here, we demonstrate that the ketogenic carbon sources, threonine, acetate and glucose, are precursors for both fatty acid and sterol synthesis, while leucine only contributes to sterol production in the tsetse fly midgut stage of the parasite. Degradation of these carbon sources into lipids was investigated using a combination of reverse genetics and analysis of radio-labelled precursors incorporation into lipids. For instance, (i) deletion of the gene encoding isovaleryl-CoA dehydrogenase, involved in the leucine degradation pathway, abolished leucine incorporation into sterols, and (ii) RNAi-mediated down-regulation of the SCP2-thiolase gene expression abolished incorporation of the three ketogenic carbon sources into sterols. The SCP2-thiolase is part of a unidirectional two-step bridge between the fatty acid precursor, acetyl-CoA, and the precursor of the mevalonate pathway leading to sterol biosynthesis, 3-hydroxy-3-methylglutaryl-CoA. Metabolic flux through this bridge is increased either in the isovaleryl-CoA dehydrogenase null mutant or when the degradation of the ketogenic carbon sources is affected. We also observed a preference for fatty acids synthesis from ketogenic carbon sources, since blocking acetyl-CoA production from both glucose and threonine abolished acetate incorporation into sterols, while incorporation of acetate into fatty acids was increased. Interestingly, the growth of the isovaleryl-CoA dehydrogenase null mutant, but not that of the parental cells, is interrupted in the absence of ketogenic carbon sources, including lipids, which demonstrates the essential role of the mevalonate pathway. We concluded that procyclic trypanosomes have a strong preference for fatty acid versus sterol biosynthesis from ketogenic carbon sources, and as a consequence, that leucine is likely to be the main source, if not the only one, used by trypanosomes in the infected insect vector digestive tract to feed the mevalonate pathway.
Collapse
Affiliation(s)
- Yoann Millerioux
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), Université de Bordeaux, CNRS UMR-5536, Bordeaux, France
| | - Muriel Mazet
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), Université de Bordeaux, CNRS UMR-5536, Bordeaux, France
| | - Guillaume Bouyssou
- Membrane Biogenesis Laboratory, CNRS-University of Bordeaux, UMR-5200, INRA Bordeaux Aquitaine, Villenave d'Ornon, France
| | - Stefan Allmann
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), Université de Bordeaux, CNRS UMR-5536, Bordeaux, France
| | - Tiila-Riikka Kiema
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Eloïse Bertiaux
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Department of Parasites and Insect Vectors, INSERM U1201, Institut Pasteur, Paris, France
| | - Laetitia Fouillen
- Membrane Biogenesis Laboratory, CNRS-University of Bordeaux, UMR-5200, INRA Bordeaux Aquitaine, Villenave d'Ornon, France
- Metabolome Facility of Bordeaux, Functional Genomics Center, Villenave d'Ornon
| | - Chandan Thapa
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Marc Biran
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), Université de Bordeaux, CNRS UMR-5536, Bordeaux, France
| | - Nicolas Plazolles
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
| | - Franziska Dittrich-Domergue
- Membrane Biogenesis Laboratory, CNRS-University of Bordeaux, UMR-5200, INRA Bordeaux Aquitaine, Villenave d'Ornon, France
| | - Aline Crouzols
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Department of Parasites and Insect Vectors, INSERM U1201, Institut Pasteur, Paris, France
| | - Rik K. Wierenga
- Faculty of Biochemistry and Molecular Medicine, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Brice Rotureau
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, Department of Parasites and Insect Vectors, INSERM U1201, Institut Pasteur, Paris, France
| | - Patrick Moreau
- Membrane Biogenesis Laboratory, CNRS-University of Bordeaux, UMR-5200, INRA Bordeaux Aquitaine, Villenave d'Ornon, France
| | - Frédéric Bringaud
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), Université de Bordeaux, CNRS UMR-5536, Bordeaux, France
- * E-mail:
| |
Collapse
|
28
|
Colasante C, Zheng F, Kemp C, Voncken F. A plant-like mitochondrial carrier family protein facilitates mitochondrial transport of di- and tricarboxylates in Trypanosoma brucei. Mol Biochem Parasitol 2018; 221:36-51. [PMID: 29581011 DOI: 10.1016/j.molbiopara.2018.03.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 02/22/2018] [Accepted: 03/21/2018] [Indexed: 12/31/2022]
Abstract
The procyclic form of the human parasite Trypanosoma brucei harbors one single, large mitochondrion containing all tricarboxylic acid (TCA) cycle enzymes and respiratory chain complexes present also in higher eukaryotes. Metabolite exchange among subcellular compartments such as the cytoplasm, the mitochondrion, and the peroxisomes is crucial for redox homeostasis and for metabolic pathways whose enzymes are dispersed among different organelles. In higher eukaryotes, mitochondrial carrier family (MCF) proteins transport TCA-cycle intermediates across the inner mitochondrial membrane. Previously, we identified several MCF members that are essential for T. brucei survival. Among these, only one MCF protein, TbMCP12, potentially could transport dicarboxylates and tricarboxylates. Here, we conducted phylogenetic and sequence analyses and functionally characterised TbMCP12 in vivo. Our results suggested that similarly to its homologues in plants, TbMCP12 transports both dicarboxylates and tricarboxylates across the mitochondrial inner membrane. Deleting this carrier in T. brucei was not lethal, while its overexpression was deleterious. Our results suggest that the intracellular abundance of TbMCP12 is an important regulatory element for the NADPH balance and mitochondrial ATP-production.
Collapse
Affiliation(s)
- Claudia Colasante
- Institute for Anatomy and Cell Biology, Division of Medical Cell Biology, Aulweg 123, University of Giessen, 35392, Giessen, Germany.
| | - Fuli Zheng
- Department of Preventive Medicine, School of Public Health, Fujian Medical University, 1 Xue Yuan Road, Fu Zhou, Fujian, PR China
| | - Cordula Kemp
- Department of Biomedical Sciences, School of Life Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom
| | - Frank Voncken
- Department of Biomedical Sciences, School of Life Sciences, University of Hull, Cottingham Road, Hull, HU6 7RX, United Kingdom
| |
Collapse
|
29
|
Deletion of transketolase triggers a stringent metabolic response in promastigotes and loss of virulence in amastigotes of Leishmania mexicana. PLoS Pathog 2018; 14:e1006953. [PMID: 29554142 PMCID: PMC5882173 DOI: 10.1371/journal.ppat.1006953] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 04/03/2018] [Accepted: 02/28/2018] [Indexed: 11/22/2022] Open
Abstract
Transketolase (TKT) is part of the non-oxidative branch of the pentose phosphate pathway (PPP). Here we describe the impact of removing this enzyme from the pathogenic protozoan Leishmania mexicana. Whereas the deletion had no obvious effect on cultured promastigote forms of the parasite, the Δtkt cells were not virulent in mice. Δtkt promastigotes were more susceptible to oxidative stress and various leishmanicidal drugs than wild-type, and metabolomics analysis revealed profound changes to metabolism in these cells. In addition to changes consistent with those directly related to the role of TKT in the PPP, central carbon metabolism was substantially decreased, the cells consumed significantly less glucose, flux through glycolysis diminished, and production of the main end products of metabolism was decreased. Only minor changes in RNA abundance from genes encoding enzymes in central carbon metabolism, however, were detected although fructose-1,6-bisphosphate aldolase activity was decreased two-fold in the knock-out cell line. We also showed that the dual localisation of TKT between cytosol and glycosomes is determined by the C-terminus of the enzyme and by engineering different variants of the enzyme we could alter its sub-cellular localisation. However, no effect on the overall flux of glucose was noted irrespective of whether the enzyme was found uniquely in either compartment, or in both. Leishmania parasites endanger over 1 billion people worldwide, infecting 300,000 people and causing 20,000 deaths annually. In this study, we scrutinized metabolism in Leishmania mexicana after deletion of the gene encoding transketolase (TKT), an enzyme involved in sugar metabolism via the pentose phosphate pathway which plays key roles in creating ribose 5-phosphate for nucleotide synthesis and also defence against oxidative stress. The insect stage of the parasite, grown in culture medium, did not suffer from any obvious growth defect after the gene was deleted. However, its metabolism changed dramatically, with metabolomics indicating profound changes to flux through the pentose phosphate pathway: decreased glucose consumption, and generally enhanced efficiency in using metabolic substrates with reduced secretion of partially oxidised end products of metabolism. This ‘stringent’ metabolism is reminiscent of the mammalian stage parasites. The cells were also more sensitive to oxidative stress inducing agents and leishmanicidal drugs. Crucially, mice inoculated with the TKT knock-out parasites did not develop an infection pointing to the enzyme playing a key role in allowing the parasites to remain viable in the host, indicating that TKT may be considered a useful target for development of new drugs against leishmaniasis.
Collapse
|
30
|
Ebersoll S, Musunda B, Schmenger T, Dirdjaja N, Bonilla M, Manta B, Ulrich K, Comini MA, Krauth-Siegel RL. A glutaredoxin in the mitochondrial intermembrane space has stage-specific functions in the thermo-tolerance and proliferation of African trypanosomes. Redox Biol 2018; 15:532-547. [PMID: 29413965 PMCID: PMC5975080 DOI: 10.1016/j.redox.2018.01.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 01/23/2018] [Indexed: 12/30/2022] Open
Abstract
Trypanosoma brucei glutaredoxin 2 (Grx2) is a dithiol glutaredoxin that is specifically located in the mitochondrial intermembrane space. Bloodstream form parasites lacking Grx2 or both, Grx2 and the cytosolic Grx1, are viable in vitro and infectious to mice suggesting that neither oxidoreductase is needed for survival or infectivity to mammals. A 37 °C to 39 °C shift changes the cellular redox milieu of bloodstream cells to more oxidizing conditions and induces a significantly stronger growth arrest in wildtype parasites compared to the mutant cells. Grx2-deficient cells ectopically expressing the wildtype form of Grx2 with its C31QFC34 active site, but not the C34S mutant, regain the sensitivity of the parental strain, indicating that the physiological role of Grx2 requires both active site cysteines. In the procyclic insect stage of the parasite, Grx2 is essential. Both alleles can be replaced if procyclic cells ectopically express authentic or C34S, but not C31S/C34S Grx2, pointing to a redox role that relies on a monothiol mechanism. RNA-interference against Grx2 causes a virtually irreversible proliferation defect. The cells adopt an elongated morphology but do not show any significant alteration in the cell cycle. The growth retardation is attenuated by high glucose concentrations. Under these conditions, procyclic cells obtain ATP by substrate level phosphorylation suggesting that Grx2 might regulate a respiratory chain component. Bloodstream T. brucei lacking glutaredoxin 2 are fully viable in vitro and in vivo. A temperature rise shifts the cellular redox state to more oxidizing conditions. Glutaredoxin 2-deficiency confers bloodstream cells with thermo-tolerance. The insect stage requires redox-active glutaredoxin 2 for viability and morphology.
Collapse
Affiliation(s)
- Samantha Ebersoll
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Blessing Musunda
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Torsten Schmenger
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Natalie Dirdjaja
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Mariana Bonilla
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400, Montevideo, Uruguay
| | - Bruno Manta
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400, Montevideo, Uruguay
| | - Kathrin Ulrich
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Marcelo A Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400, Montevideo, Uruguay
| | - R Luise Krauth-Siegel
- Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
| |
Collapse
|
31
|
Giordana L, Sosa MH, Leroux AE, Mendoza EFR, Petray P, Nowicki C. Molecular and functional characterization of two malic enzymes from Leishmania parasites. Mol Biochem Parasitol 2017; 219:67-76. [PMID: 29128656 DOI: 10.1016/j.molbiopara.2017.11.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 10/31/2017] [Accepted: 11/02/2017] [Indexed: 10/18/2022]
Abstract
Leishmania parasites cause a broad spectrum of clinical manifestations in humans and the available clinical treatments are far from satisfactory. Since these pathogens require large amounts of NADPH to maintain intracellular redox homeostasis, oxidoreductases that catalyze the production of NADPH are considered as potential drug targets against these diseases. In the sequenced genomes of most Leishmania spp. two putative malic enzymes (MEs) with an identity of about 55% have been identified. In this work, the ME from L. major (LmjF24.0770, Lmj_ME-70) and its less similar homolog from L. mexicana (LmxM.24.0761, Lmex_ME-61) were cloned and functionally characterized. Both MEs specifically catalyzed NADPH production, but only Lmex_ME-61 was activated by l-aspartate. Unlike the allosterically activated human ME, Lmex_ME-61 exhibited typical hyperbolic curves without any sign of cooperativity in the absence of l-aspartate. Moreover, Lmex_ME-61 and Lmj_ME-70 differ from higher eukaryotic homologs in that they display dimeric instead of tetrameric molecular organization. Homology modeling analysis showed that Lmex_ME-61 and Lmj_ME-70 notably differ in their surface charge distribution; this feature encompasses the coenzyme binding pockets as well. However, in both isozymes, the residues directly involved in the coenzyme binding exhibited a good degree of conservation. Besides, only Lmex_ME-61 and its closest homologs were immunodetected in cell-free extracts from L. mexicana, L. amazonensis and L. braziliensis promastigotes. Our findings provide a first glimpse into the biochemical properties of leishmanial MEs and suggest that MEs could be potentially related to the metabolic differences among the species of Leishmania parasites.
Collapse
Affiliation(s)
- Lucila Giordana
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Química y Fisicoquímica Biológica (IQUIFIB-CONICET), Junín 956, C1113AAD, Buenos Aires, Argentina
| | - Máximo Hernán Sosa
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Investigaciones Farmacológicas en alianza estratégica con UBA-CONICET (ININFA) Junín 956, C1113AAD, Buenos Aires, Argentina
| | - Alejandro E Leroux
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA)-CONICET -Partner Institute of the Max Planck Society, Buenos Aires C1415FQD, Argentina
| | - Elkin F Rodas Mendoza
- Universidade Estadual Paulista (Unesp), Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal, Brazil
| | - Patricia Petray
- Universidad de Buenos Aires, Instituto de Microbiología y Parasitología Médica (IMPaM-CONICET), Paraguay 2155, C1121ABG, Buenos Aires, Argentina
| | - Cristina Nowicki
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Instituto de Química y Fisicoquímica Biológica (IQUIFIB-CONICET), Junín 956, C1113AAD, Buenos Aires, Argentina.
| |
Collapse
|
32
|
Mwenechanya R, Kovářová J, Dickens NJ, Mudaliar M, Herzyk P, Vincent IM, Weidt SK, Burgess KE, Burchmore RJS, Pountain AW, Smith TK, Creek DJ, Kim DH, Lepesheva GI, Barrett MP. Sterol 14α-demethylase mutation leads to amphotericin B resistance in Leishmania mexicana. PLoS Negl Trop Dis 2017. [PMID: 28622334 PMCID: PMC5498063 DOI: 10.1371/journal.pntd.0005649] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Amphotericin B has emerged as the therapy of choice for use against the leishmaniases. Administration of the drug in its liposomal formulation as a single injection is being promoted in a campaign to bring the leishmaniases under control. Understanding the risks and mechanisms of resistance is therefore of great importance. Here we select amphotericin B-resistant Leishmania mexicana parasites with relative ease. Metabolomic analysis demonstrated that ergosterol, the sterol known to bind the drug, is prevalent in wild-type cells, but diminished in the resistant line, where alternative sterols become prevalent. This indicates that the resistance phenotype is related to loss of drug binding. Comparing sequences of the parasites' genomes revealed a plethora of single nucleotide polymorphisms that distinguish wild-type and resistant cells, but only one of these was found to be homozygous and associated with a gene encoding an enzyme in the sterol biosynthetic pathway, sterol 14α-demethylase (CYP51). The mutation, N176I, is found outside of the enzyme's active site, consistent with the fact that the resistant line continues to produce the enzyme's product. Expression of wild-type sterol 14α-demethylase in the resistant cells caused reversion to drug sensitivity and a restoration of ergosterol synthesis, showing that the mutation is indeed responsible for resistance. The amphotericin B resistant parasites become hypersensitive to pentamidine and also agents that induce oxidative stress. This work reveals the power of combining polyomics approaches, to discover the mechanism underlying drug resistance as well as offering novel insights into the selection of resistance to amphotericin B itself.
Collapse
Affiliation(s)
- Roy Mwenechanya
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
| | - Julie Kovářová
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
| | - Nicholas J. Dickens
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
| | - Manikhandan Mudaliar
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Pawel Herzyk
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Isabel M. Vincent
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
| | - Stefan K. Weidt
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Karl E. Burgess
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Richard J. S. Burchmore
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Andrew W. Pountain
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
| | - Terry K. Smith
- Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St. Andrews, Fife, United Kingdom
| | - Darren J. Creek
- Drug Delivery, Disposition & Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Dong-Hyun Kim
- Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Galina I. Lepesheva
- Vanderbilt University School of Medicine, Nashville, TN, United States of America
| | - Michael P. Barrett
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
- * E-mail:
| |
Collapse
|
33
|
Ranzani AT, Nowicki C, Wilkinson SR, Cordeiro AT. Identification of Specific Inhibitors of Trypanosoma cruzi Malic Enzyme Isoforms by Target-Based HTS. SLAS DISCOVERY 2017; 22:1150-1161. [PMID: 28459632 DOI: 10.1177/2472555217706649] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Trypanosoma cruzi is the causative agent of Chagas disease. The lack of an efficient and safe treatment supports the research into novel metabolic targets, with the malic enzyme (ME) representing one such potential candidate. T. cruzi expresses a cytosolic (TcMEc) and a mitochondrial (TcMEm) ME isoform, with these activities functioning to generate NADPH, a key source of reducing equivalents that drives a range of anabolic and protective processes. To identify specific inhibitors that target TcMEs, two independent high-throughput screening strategies using a diversity library containing 30,000 compounds were employed. IC50 values of 262 molecules were determined for both TcMEs, as well as for three human ME isoforms, with the inhibitors clustered into six groups according to their chemical similarity. The most potent hits belonged to a sulfonamide group that specifically target TcMEc. Moreover, several selected inhibitors of both TcMEs showed a trypanocidal effect against the replicative forms of T. cruzi. The chemical diversity observed among those compounds that inhibit TcMEs activity emphasizes the druggability of these enzymes, with a sulfonamide-based subset of compounds readily able to block TcMEc function at a low nanomolar range.
Collapse
Affiliation(s)
- Americo T Ranzani
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Sao Paulo, Brazil.,Institute of Biology, University of Campinas, Campinas, Sao Paulo, Brazil
| | - Cristina Nowicki
- Facultad de Farmacia y Bioquímica, Instituto de Química y Fisicoquímica Biológica (IQUIFIB-CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Shane R Wilkinson
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Artur T Cordeiro
- Brazilian Biosciences National Laboratory, Brazilian Center for Research in Energy and Materials, Campinas, Sao Paulo, Brazil
| |
Collapse
|
34
|
Ghosh AK, Saini S, Das S, Mandal A, Sardar AH, Ansari MY, Abhishek K, Kumar A, Singh R, Verma S, Equbal A, Ali V, Das P. Glucose-6-phosphate dehydrogenase and Trypanothione reductase interaction protects Leishmania donovani from metalloid mediated oxidative stress. Free Radic Biol Med 2017; 106:10-23. [PMID: 28179112 DOI: 10.1016/j.freeradbiomed.2017.02.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 02/02/2017] [Accepted: 02/04/2017] [Indexed: 10/20/2022]
Abstract
Exploration of metabolons as viable drug target is rare in kinetoplastid biology. Here we present a novel protein-protein interaction among Glucose-6-phosphate dehydrogenase (LdG6PDH) and Trypanothione reductase (LdTryR) of Leishmania donovani displaying interconnection between central glucose metabolism and thiol metabolism of this parasite. Digitonin fractionation patterns observed through immunoblotting indicated localisation of both LdG6PDH and LdTryR in cytosol. In-silico and in-vitro interaction observed by size exclusion chromatography, co-purification, pull-down assay and spectrofluorimetric analysis revealed LdG6PDH and LdTryR physically interact with each other in a NADPH dependent manner. Coupled enzymatic assay displayed that NADPH generation was severely impaired by addition of SbIII, AsIII and TeIV extraneously, which hint towards metalloid driven structural changes of the interacting proteins. Co-purification patterns and pull-down assays also depicted that metalloids (SbIII, AsIII and TeIV) hinder the in-vitro interaction of these two enzymes. Surprisingly, metalloids at sub-lethal concentrations induced the in-vivo interaction of LdG6PDH and LdTryR, as analyzed by pull-down assays and fluorescence microscopy signifying protection against metalloid mediated ROS. Inhibition of LdTryR by thioridazine in LdG6PDH-/- parasites resulted in metalloid induced apoptotic death of the parasites due to abrupt fall in reduced thiol content, disrupted NADPH/NADP+ homeostasis and lethal oxidative stress. Interestingly, clinical isolates of L.donovani resistant to SAG exhibited enhanced interaction between LdG6PDH and LdTryR and showed cross resistivity towards AsIII and TeIV. Thus, our findings propose the metabolon of LdG6PDH and LdTryR as an alternate therapeutic target and provide mechanistic insight about metalloid resistance in Visceral Leishmaniasis.
Collapse
Affiliation(s)
- Ayan Kumar Ghosh
- Division of Molecular Biology, Bioinformatics and Molecular Biochemistry & Cell Biology, Rajendra Memorial Research Institute of Medical Sciences (I.C.M.R.), Agamkuan, Patna 800007, Bihar, India
| | - Savita Saini
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Export Promotion Industrial Park, Hajipur, Vaishali 844101, Bihar, India
| | - Sushmita Das
- Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna 801505, Bihar, India
| | - Abhishek Mandal
- Division of Molecular Biology, Bioinformatics and Molecular Biochemistry & Cell Biology, Rajendra Memorial Research Institute of Medical Sciences (I.C.M.R.), Agamkuan, Patna 800007, Bihar, India
| | - Abul Hasan Sardar
- Division of Molecular Biology, Bioinformatics and Molecular Biochemistry & Cell Biology, Rajendra Memorial Research Institute of Medical Sciences (I.C.M.R.), Agamkuan, Patna 800007, Bihar, India
| | - Md Yousuf Ansari
- Division of Molecular Biology, Bioinformatics and Molecular Biochemistry & Cell Biology, Rajendra Memorial Research Institute of Medical Sciences (I.C.M.R.), Agamkuan, Patna 800007, Bihar, India
| | - Kumar Abhishek
- Division of Molecular Biology, Bioinformatics and Molecular Biochemistry & Cell Biology, Rajendra Memorial Research Institute of Medical Sciences (I.C.M.R.), Agamkuan, Patna 800007, Bihar, India
| | - Ajay Kumar
- Division of Molecular Biology, Bioinformatics and Molecular Biochemistry & Cell Biology, Rajendra Memorial Research Institute of Medical Sciences (I.C.M.R.), Agamkuan, Patna 800007, Bihar, India
| | - Ruby Singh
- Division of Molecular Biology, Bioinformatics and Molecular Biochemistry & Cell Biology, Rajendra Memorial Research Institute of Medical Sciences (I.C.M.R.), Agamkuan, Patna 800007, Bihar, India
| | - Sudha Verma
- Division of Molecular Biology, Bioinformatics and Molecular Biochemistry & Cell Biology, Rajendra Memorial Research Institute of Medical Sciences (I.C.M.R.), Agamkuan, Patna 800007, Bihar, India
| | - Asif Equbal
- Division of Molecular Biology, Bioinformatics and Molecular Biochemistry & Cell Biology, Rajendra Memorial Research Institute of Medical Sciences (I.C.M.R.), Agamkuan, Patna 800007, Bihar, India
| | - Vahab Ali
- Division of Molecular Biology, Bioinformatics and Molecular Biochemistry & Cell Biology, Rajendra Memorial Research Institute of Medical Sciences (I.C.M.R.), Agamkuan, Patna 800007, Bihar, India
| | - Pradeep Das
- Division of Molecular Biology, Bioinformatics and Molecular Biochemistry & Cell Biology, Rajendra Memorial Research Institute of Medical Sciences (I.C.M.R.), Agamkuan, Patna 800007, Bihar, India.
| |
Collapse
|
35
|
Lin S, Voyton C, Morris MT, Ackroyd PC, Morris JC, Christensen KA. pH regulation in glycosomes of procyclic form Trypanosoma brucei. J Biol Chem 2017; 292:7795-7805. [PMID: 28348078 DOI: 10.1074/jbc.m117.784173] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Indexed: 01/17/2023] Open
Abstract
Here we report the use of a fluorescein-tagged peroxisomal targeting sequence peptide (F-PTS1, acetyl-C{K(FITC)}GGAKL) for investigating pH regulation of glycosomes in live procyclic form Trypanosoma brucei When added to cells, this fluorescent peptide is internalized within vesicular structures, including glycosomes, and can be visualized after 30-60 min. Using F-PTS1 we are able to observe the pH conditions inside glycosomes in response to starvation conditions. Previous studies have shown that in the absence of glucose, the glycosome exhibits mild acidification from pH 7.4 ± 0.2 to 6.8 ± 0.2. Our results suggest that this response occurs under proline starvation as well. This pH regulation is found to be independent from cytosolic pH and requires a source of Na+ ions. Glycosomes were also observed to be more resistant to external pH changes than the cytosol; placement of cells in acidic buffers (pH 5) reduced the pH of the cytosol by 0.8 ± 0.1 pH units, whereas glycosomal pH decreases by 0.5 ± 0.1 pH units. This observation suggests that regulation of glycosomal pH is different and independent from cytosolic pH regulation. Furthermore, pH regulation is likely to work by an active process, because cells depleted of ATP with 2-deoxyglucose and sodium azide were unable to properly regulate pH. Finally, inhibitor studies with bafilomycin and EIPA suggest that both V-ATPases and Na+/H+ exchangers are required for glycosomal pH regulation.
Collapse
Affiliation(s)
- Sheng Lin
- From the Departments of Chemistry and
| | - Charles Voyton
- From the Departments of Chemistry and.,the Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602
| | - Meredith T Morris
- Genetics and Biochemistry, Clemson University, Clemson, South Carolina 29634 and
| | - P Christine Ackroyd
- the Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602
| | - James C Morris
- Genetics and Biochemistry, Clemson University, Clemson, South Carolina 29634 and
| | - Kenneth A Christensen
- the Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602
| |
Collapse
|
36
|
Li FJ, Xu ZS, Soo ADS, Lun ZR, He CY. ATP-driven and AMPK-independent autophagy in an early branching eukaryotic parasite. Autophagy 2017; 13:715-729. [PMID: 28121493 DOI: 10.1080/15548627.2017.1280218] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Autophagy is a catabolic cellular process required to maintain protein synthesis, energy production and other essential activities in starved cells. While the exact nutrient sensor(s) is yet to be identified, deprivation of amino acids, glucose, growth factor and other nutrients can serve as metabolic stimuli to initiate autophagy in higher eukaryotes. In the early-branching unicellular parasite Trypanosoma brucei, which can proliferate as procyclic form (PCF) in the tsetse fly or as bloodstream form (BSF) in animal hosts, autophagy is robustly triggered by amino acid deficiency but not by glucose depletion. Taking advantage of the clearly defined adenosine triphosphate (ATP) production pathways in T. brucei, we have shown that autophagic activity depends on the levels of cellular ATP production, using either glucose or proline as a carbon source. While autophagosome formation positively correlates with cellular ATP levels; perturbation of ATP production by removing carbon sources or genetic silencing of enzymes involved in ATP generation pathways, also inhibited autophagy. This obligate energy dependence and the lack of glucose starvation-induced autophagy in T. brucei may reflect an adaptation to its specialized, parasitic life style.
Collapse
Affiliation(s)
- Feng-Jun Li
- a Department of Biological Sciences , National University of Singapore , Singapore
| | - Zhi-Shen Xu
- b State Key Laboratory of Biocontrol, School of Life Sciences, and Key Laboratory of Tropical Diseases and Control of the Ministry of Education , Zhongshan Medical School, Sun Yat-Sen University , Guangzhou , China
| | - Andy D S Soo
- a Department of Biological Sciences , National University of Singapore , Singapore
| | - Zhao-Rong Lun
- b State Key Laboratory of Biocontrol, School of Life Sciences, and Key Laboratory of Tropical Diseases and Control of the Ministry of Education , Zhongshan Medical School, Sun Yat-Sen University , Guangzhou , China
| | - Cynthia Y He
- a Department of Biological Sciences , National University of Singapore , Singapore.,c Centre for BioImaging Sciences , National University of Singapore , Singapore
| |
Collapse
|
37
|
Saini S, Kumar Ghosh A, Singh R, Das S, Abhishek K, Kumar A, Verma S, Mandal A, Hasan Sardar A, Purkait B, Kumar A, Kumar Sinha K, Das P. Glucose deprivation induced upregulation of phosphoenolpyruvate carboxykinase modulates virulence in Leishmania donovani. Mol Microbiol 2016; 102:1020-1042. [PMID: 27664030 DOI: 10.1111/mmi.13534] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2016] [Indexed: 01/20/2023]
Abstract
Various physiological stimuli trigger the conversion of noninfective Leishmania donovani promastigotes to the infective form. Here, we present the first evidence of the effect of glucose starvation, on virulence and survival of these parasites. Glucose starvation resulted in a decrease in metabolically active parasites and their proliferation. However, this was reversed by supplementation of gluconeogenic amino acids. Glucose starvation induced metacyclogenesis and enhanced virulence through protein kinase A regulatory subunit (LdPKAR1) mediated autophagy. Glucose starvation driven oxidative stress upregulated the antioxidant machinery, culminating in increased infectivity and greater parasitic load in primary macrophages. Interestingly, phosphoenolpyruvate carboxykinase (LdPEPCK), a gluconeogenic enzyme, exhibited the highest activity under glucose starvation to regulate growth of L. donovani by alternatively utilising amino acids. Deletion of LdPEPCK (Δpepck) decreased virulent traits and parasitic load in primary macrophages but increased autophagosome formation in the mutant parasites. Furthermore, Δpepck parasites failed to activate the Pentose Phosphate Pathway shunt, abrogating NADPH/NADP+ homoeostasis, conferring increased susceptibility towards oxidants following glucose starvation. In conclusion, this study showed that L. donovani undertakes metabolic rearrangements via gluconeogenesis under glucose starvation for acquiring virulence and its survival in the hostile environment.
Collapse
Affiliation(s)
- Savita Saini
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur, Bihar, India.,Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Indian Council of Medical Research, Patna, Bihar, India
| | - Ayan Kumar Ghosh
- Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Indian Council of Medical Research, Patna, Bihar, India
| | - Ruby Singh
- Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Indian Council of Medical Research, Patna, Bihar, India
| | - Sushmita Das
- Department of Microbiology, All India Institute of Medical Sciences, Patna, Bihar, India
| | - Kumar Abhishek
- Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Indian Council of Medical Research, Patna, Bihar, India
| | - Ajay Kumar
- Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Indian Council of Medical Research, Patna, Bihar, India
| | - Sudha Verma
- Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Indian Council of Medical Research, Patna, Bihar, India
| | - Abhishek Mandal
- Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Indian Council of Medical Research, Patna, Bihar, India
| | - Abul Hasan Sardar
- Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Indian Council of Medical Research, Patna, Bihar, India
| | - Bidyut Purkait
- Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Indian Council of Medical Research, Patna, Bihar, India
| | - Ashish Kumar
- Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Indian Council of Medical Research, Patna, Bihar, India
| | - Kislay Kumar Sinha
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur, Bihar, India
| | - Pradeep Das
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur, Bihar, India.,Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Indian Council of Medical Research, Patna, Bihar, India
| |
Collapse
|
38
|
The Pentose Phosphate Pathway in Parasitic Trypanosomatids. Trends Parasitol 2016; 32:622-634. [DOI: 10.1016/j.pt.2016.04.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/11/2016] [Accepted: 04/13/2016] [Indexed: 12/20/2022]
|
39
|
González-Marcano E, Acosta H, Mijares A, Concepción JL. Kinetic and molecular characterization of the pyruvate phosphate dikinase from Trypanosoma cruzi. Exp Parasitol 2016; 165:81-7. [PMID: 27003459 DOI: 10.1016/j.exppara.2016.03.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 03/14/2016] [Accepted: 03/18/2016] [Indexed: 11/18/2022]
Abstract
Trypanosoma cruzi, like other trypanosomatids analyzed so far, can use both glucose and amino acids as carbon and energy source. In these parasites, glycolysis is compartmentalized in glycosomes, authentic but specialized peroxisomes. The major part of this pathway, as well as a two-branched glycolytic auxiliary system, are present in these organelles. The first enzyme of one branch of this auxiliary system is the PPi-dependent pyruvate phosphate dikinase (PPDK) that converts phosphoenolpyruvate (PEP), inorganic pyrophosphate (PPi) and AMP into pyruvate, inorganic phosphate (Pi) and ATP, thus contributing to the ATP/ADP balance within the glycosomes. In this work we cloned, expressed and purified the T. cruzi PPDK. It kinetic parameters were determined, finding KM values for PEP, PPi and AMP of 320, 70 and 17 μM, respectively. Using molecular exclusion chromatography, two native forms of the enzyme were found with estimated molecular weights of 200 and 100 kDa, corresponding to a homodimer and monomer, respectively. It was established that T. cruzi PPDK's specific activity can be enhanced up to 2.6 times by the presence of ammonium in the assay mixture. During growth of epimastigotes in batch culture an apparent decrease in the specific activity of PPDK was observed. However, when its activity is normalized for the presence of ammonium in the medium, no significant modification of the enzyme activity per cell in time was found.
Collapse
Affiliation(s)
- Eglys González-Marcano
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, La Hechicera, Mérida 5101, Venezuela.
| | - Héctor Acosta
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, La Hechicera, Mérida 5101, Venezuela.
| | - Alfredo Mijares
- Laboratorio de Fisiología de Parásitos, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas 1020-A, Venezuela.
| | - Juan Luis Concepción
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, La Hechicera, Mérida 5101, Venezuela.
| |
Collapse
|
40
|
Štáfková J, Mach J, Biran M, Verner Z, Bringaud F, Tachezy J. Mitochondrial pyruvate carrier in Trypanosoma brucei. Mol Microbiol 2016; 100:442-56. [PMID: 26748989 DOI: 10.1111/mmi.13325] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2016] [Indexed: 12/30/2022]
Abstract
Pyruvate is a key product of glycolysis that regulates the energy metabolism of cells. In Trypanosoma brucei, the causative agent of sleeping sickness, the fate of pyruvate varies dramatically during the parasite life cycle. In bloodstream forms, pyruvate is mainly excreted, whereas in tsetse fly forms, pyruvate is metabolized in mitochondria yielding additional ATP molecules. The character of the molecular machinery that mediates pyruvate transport across mitochondrial membrane was elusive until the recent discovery of mitochondrial pyruvate carrier (MPC) in yeast and mammals. Here, we characterized pyruvate import into mitochondrion of T. brucei. We identified mpc1 and mpc2 homologs in the T. brucei genome with attributes of MPC protein family and we demonstrated that both proteins are present in the mitochondrial membrane of the parasite. Investigations of mpc1 or mpc2 gene knock-out cells proved that T. brucei MPC1/2 proteins facilitate mitochondrial pyruvate transport. Interestingly, MPC is expressed not only in procyclic trypanosomes with fully activated mitochondria but also in bloodstream trypanosomes in which most of pyruvate is excreted. Moreover, MPC appears to be essential for bloodstream forms, supporting the recently emerging picture that the functions of mitochondria in bloodstream forms are more diverse than it was originally thought.
Collapse
Affiliation(s)
- Jitka Štáfková
- Department of Parasitology, Faculty of Science, Charles University in Prague, Czech Republic
| | - Jan Mach
- Department of Parasitology, Faculty of Science, Charles University in Prague, Czech Republic
| | - Marc Biran
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), UMR5536 CNRS
| | - Zdeněk Verner
- Department of Parasitology, Faculty of Science, Charles University in Prague, Czech Republic
| | - Frédéric Bringaud
- Centre de Résonance Magnétique des Systèmes Biologiques (RMSB), UMR5536 CNRS.,Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), UMR5234 CNRS, Université de Bordeaux, Bordeaux, France
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University in Prague, Czech Republic
| |
Collapse
|
41
|
From population ecology to metabolism: growth of Trypanosoma evansi, and implications of glucose depletion, in a live host. BIOCHEM SYST ECOL 2015. [DOI: 10.1016/j.bse.2015.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
42
|
Haanstra JR, González-Marcano EB, Gualdrón-López M, Michels PAM. Biogenesis, maintenance and dynamics of glycosomes in trypanosomatid parasites. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:1038-48. [PMID: 26384872 DOI: 10.1016/j.bbamcr.2015.09.015] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 12/31/2022]
Abstract
Peroxisomes of organisms belonging to the protist group Kinetoplastea, which include trypanosomatid parasites of the genera Trypanosoma and Leishmania, are unique in playing a crucial role in glycolysis and other parts of intermediary metabolism. They sequester the majority of the glycolytic enzymes and hence are called glycosomes. Their glycosomal enzyme content can vary strongly, particularly quantitatively, between different trypanosomatid species, and within each species during its life cycle. Turnover of glycosomes by autophagy of redundant ones and biogenesis of a new population of organelles play a pivotal role in the efficient adaptation of the glycosomal metabolic repertoire to the sudden, major nutritional changes encountered during the transitions in their life cycle. The overall mechanism of glycosome biogenesis is similar to that of peroxisomes in other organisms, but the homologous peroxins involved display low sequence conservation as well as variations in motifs mediating crucial protein-protein interactions in the process. The correct compartmentalisation of enzymes is essential for the regulation of the trypanosomatids' metabolism and consequently for their viability. For Trypanosoma brucei it was shown that glycosomes also play a crucial role in its life-cycle regulation: a crucial developmental control switch involves the translocation of a protein phosphatase from the cytosol into the organelles. Many glycosomal proteins are differentially phosphorylated in different life-cycle stages, possibly indicative of regulation of enzyme activities as an additional means to adapt the metabolic network to the different environmental conditions encountered.
Collapse
Affiliation(s)
- Jurgen R Haanstra
- Systems Bioinformatics, Vrije Universiteit Amsterdam, The Netherlands
| | - Eglys B González-Marcano
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela
| | - Melisa Gualdrón-López
- Federal University of Minas Gerais, Laboratory of Immunoregulation of Infectious Diseases, Department of Biochemistry and Immunology, Institute for Biological Sciences, Belo Horizonte, Brazil
| | - Paul A M Michels
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela; Centre for Translational and Chemical Biology, Institute of Structural and Molecular Biology, School of Biological Sciences, University of Edinburgh, United Kingdom.
| |
Collapse
|
43
|
Bringaud F, Biran M, Millerioux Y, Wargnies M, Allmann S, Mazet M. Combining reverse genetics and nuclear magnetic resonance-based metabolomics unravels trypanosome-specific metabolic pathways. Mol Microbiol 2015; 96:917-26. [PMID: 25753950 DOI: 10.1111/mmi.12990] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2015] [Indexed: 01/20/2023]
Abstract
Numerous eukaryotes have developed specific metabolic traits that are not present in extensively studied model organisms. For instance, the procyclic insect form of Trypanosoma brucei, a parasite responsible for sleeping sickness in its mammalian-specific bloodstream form, metabolizes glucose into excreted succinate and acetate through pathways with unique features. Succinate is primarily produced from glucose-derived phosphoenolpyruvate in peroxisome-like organelles, also known as glycosomes, by a soluble NADH-dependent fumarate reductase only described in trypanosomes so far. Acetate is produced in the mitochondrion of the parasite from acetyl-CoA by a CoA-transferase, which forms an ATP-producing cycle with succinyl-CoA synthetase. The role of this cycle in ATP production was recently demonstrated in procyclic trypanosomes and has only been proposed so far for anaerobic organisms, in addition to trypanosomatids. We review how nuclear magnetic resonance spectrometry can be used to analyze the metabolic network perturbed by deletion (knockout) or downregulation (RNAi) of the candidate genes involved in these two particular metabolic pathways of procyclic trypanosomes. The role of succinate and acetate production in trypanosomes is discussed, as well as the connections between the succinate and acetate branches, which increase the metabolic flexibility probably required by the parasite to deal with environmental changes such as oxidative stress.
Collapse
Affiliation(s)
- Frédéric Bringaud
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR-5536 Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076, Bordeaux, France
| | - Marc Biran
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR-5536 Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076, Bordeaux, France
| | - Yoann Millerioux
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR-5536 Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076, Bordeaux, France
| | - Marion Wargnies
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR-5536 Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076, Bordeaux, France
| | - Stefan Allmann
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR-5536 Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076, Bordeaux, France
| | - Muriel Mazet
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR-5536 Université de Bordeaux, CNRS, 146 rue Léo Saignat, 33076, Bordeaux, France
| |
Collapse
|
44
|
Ghosh AK, Sardar AH, Mandal A, Saini S, Abhishek K, Kumar A, Purkait B, Singh R, Das S, Mukhopadhyay R, Roy S, Das P. Metabolic reconfiguration of the central glucose metabolism: a crucial strategy of Leishmania donovani for its survival during oxidative stress. FASEB J 2015; 29:2081-98. [PMID: 25690656 DOI: 10.1096/fj.14-258624] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 01/09/2015] [Indexed: 12/15/2022]
Abstract
Understanding the mechanism that allows the intracellular protozoan parasite Leishmania donovani (Ld) to respond to reactive oxygen species (ROS) is of increasing therapeutic importance because of the continuing resistance toward antileishmanial drugs and for determining the illusive survival strategy of these parasites. A shift in primary carbon metabolism is the fastest response to oxidative stress. A (14)CO2 evolution study, expression of glucose transporters together with consumption assays, indicated a shift in metabolic flux of the parasites from glycolysis toward pentose phosphate pathway (PPP) when exposed to different oxidants in vitro/ex vivo. Changes in gene expression, protein levels, and enzyme activities all pointed to a metabolic reconfiguration of the central glucose metabolism in response to oxidants. Generation of glucose-6-phosphate dehydrogenase (G6PDH) (∼5-fold) and transaldolase (TAL) (∼4.2-fold) overexpressing Ld cells reaffirmed that lethal doses of ROS were counterbalanced by effective manipulation of NADPH:NADP(+) ratio and stringent maintenance of reduced thiol content. The extent of protein carbonylation and accumulation of lipid peroxidized products were also found to be less in overexpressed cell lines. Interestingly, the LD50 of sodium antimony gluconate (SAG), amphotericin-B (AmB), and miltefosine were significantly high toward overexpressing parasites. Consequently, this study illustrates that Ld strategizes a metabolic reconfiguration for replenishment of NADPH pool to encounter oxidative challenges.
Collapse
Affiliation(s)
- Ayan K Ghosh
- *Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (Indian Council of Medical Research), Agamkuan, Patna, Bihar, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park, Hajipur, Vaishali, Bihar, India; Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna, Bihar, India; and Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Abul H Sardar
- *Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (Indian Council of Medical Research), Agamkuan, Patna, Bihar, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park, Hajipur, Vaishali, Bihar, India; Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna, Bihar, India; and Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Abhishek Mandal
- *Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (Indian Council of Medical Research), Agamkuan, Patna, Bihar, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park, Hajipur, Vaishali, Bihar, India; Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna, Bihar, India; and Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Savita Saini
- *Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (Indian Council of Medical Research), Agamkuan, Patna, Bihar, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park, Hajipur, Vaishali, Bihar, India; Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna, Bihar, India; and Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Kumar Abhishek
- *Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (Indian Council of Medical Research), Agamkuan, Patna, Bihar, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park, Hajipur, Vaishali, Bihar, India; Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna, Bihar, India; and Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Ashish Kumar
- *Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (Indian Council of Medical Research), Agamkuan, Patna, Bihar, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park, Hajipur, Vaishali, Bihar, India; Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna, Bihar, India; and Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Bidyut Purkait
- *Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (Indian Council of Medical Research), Agamkuan, Patna, Bihar, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park, Hajipur, Vaishali, Bihar, India; Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna, Bihar, India; and Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Ruby Singh
- *Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (Indian Council of Medical Research), Agamkuan, Patna, Bihar, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park, Hajipur, Vaishali, Bihar, India; Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna, Bihar, India; and Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Sushmita Das
- *Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (Indian Council of Medical Research), Agamkuan, Patna, Bihar, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park, Hajipur, Vaishali, Bihar, India; Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna, Bihar, India; and Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Rupkatha Mukhopadhyay
- *Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (Indian Council of Medical Research), Agamkuan, Patna, Bihar, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park, Hajipur, Vaishali, Bihar, India; Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna, Bihar, India; and Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Syamal Roy
- *Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (Indian Council of Medical Research), Agamkuan, Patna, Bihar, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park, Hajipur, Vaishali, Bihar, India; Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna, Bihar, India; and Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| | - Pradeep Das
- *Division of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences (Indian Council of Medical Research), Agamkuan, Patna, Bihar, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Export Promotion Industrial Park, Hajipur, Vaishali, Bihar, India; Department of Microbiology, All India Institute of Medical Sciences, Phulwarisharif, Patna, Bihar, India; and Division of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Jadavpur, Kolkata, India
| |
Collapse
|
45
|
Verner Z, Basu S, Benz C, Dixit S, Dobáková E, Faktorová D, Hashimi H, Horáková E, Huang Z, Paris Z, Peña-Diaz P, Ridlon L, Týč J, Wildridge D, Zíková A, Lukeš J. Malleable mitochondrion of Trypanosoma brucei. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 315:73-151. [PMID: 25708462 DOI: 10.1016/bs.ircmb.2014.11.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The importance of mitochondria for a typical aerobic eukaryotic cell is undeniable, as the list of necessary mitochondrial processes is steadily growing. Here, we summarize the current knowledge of mitochondrial biology of an early-branching parasitic protist, Trypanosoma brucei, a causative agent of serious human and cattle diseases. We present a comprehensive survey of its mitochondrial pathways including kinetoplast DNA replication and maintenance, gene expression, protein and metabolite import, major metabolic pathways, Fe-S cluster synthesis, ion homeostasis, organellar dynamics, and other processes. As we describe in this chapter, the single mitochondrion of T. brucei is everything but simple and as such rivals mitochondria of multicellular organisms.
Collapse
Affiliation(s)
- Zdeněk Verner
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic; Present address: Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia; Present address: Faculty of Sciences, Charles University, Prague, Czech Republic
| | - Somsuvro Basu
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic; Present address: Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Germany
| | - Corinna Benz
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Sameer Dixit
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Eva Dobáková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic; Present address: Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Drahomíra Faktorová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Hassan Hashimi
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Eva Horáková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic
| | - Zhenqiu Huang
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Zdeněk Paris
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic
| | - Priscila Peña-Diaz
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic
| | - Lucie Ridlon
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic; Present address: Salk Institute, La Jolla, San Diego, USA
| | - Jiří Týč
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - David Wildridge
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic
| | - Alena Zíková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| |
Collapse
|
46
|
Experimental resistance to drug combinations in Leishmania donovani: metabolic and phenotypic adaptations. Antimicrob Agents Chemother 2015; 59:2242-55. [PMID: 25645828 DOI: 10.1128/aac.04231-14] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Together with vector control, chemotherapy is an essential tool for the control of visceral leishmaniasis (VL), but its efficacy is jeopardized by growing resistance and treatment failure against first-line drugs. To delay the emergence of resistance, the use of drug combinations of existing antileishmanial agents has been tested systematically in clinical trials for the treatment of visceral leishmaniasis (VL). In vitro, Leishmania donovani promastigotes are able to develop experimental resistance to several combinations of different antileishmanial drugs after 10 weeks of drug pressure. Using an untargeted liquid chromatography-mass spectrometry (LC-MS) metabolomics approach, we identified metabolic changes in lines that were experimentally resistant to drug combinations and their respective single-resistant lines. This highlighted both collective metabolic changes (found in all combination therapy-resistant [CTR] lines) and specific ones (found in certain CTR lines). We demonstrated that single-resistant and CTR parasite cell lines show distinct metabolic adaptations, which all converge on the same defensive mechanisms that were experimentally validated: protection against drug-induced and external oxidative stress and changes in membrane fluidity. The membrane fluidity changes were accompanied by changes in drug uptake only in the lines that were resistant against drug combinations with antimonials, and surprisingly, drug accumulation was higher in these lines. Together, these results highlight the importance and the central role of protection against oxidative stress in the different resistant lines. Ultimately, these phenotypic changes might interfere with the mode of action of all drugs that are currently used for the treatment of VL and should be taken into account in drug development.
Collapse
|
47
|
Triacylglycerol Storage in Lipid Droplets in Procyclic Trypanosoma brucei. PLoS One 2014; 9:e114628. [PMID: 25493940 PMCID: PMC4262433 DOI: 10.1371/journal.pone.0114628] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 11/11/2014] [Indexed: 11/19/2022] Open
Abstract
Carbon storage is likely to enable adaptation of trypanosomes to nutritional challenges or bottlenecks during their stage development and migration in the tsetse. Lipid droplets are candidates for this function. This report shows that feeding of T. brucei with oleate results in a 4-5 fold increase in the number of lipid droplets, as quantified by confocal fluorescence microscopy and by flow cytometry of BODIPY 493/503-stained cells. The triacylglycerol (TAG) content also increased 4-5 fold, and labeled oleate is incorporated into TAG. Fatty acid carbon can thus be stored as TAG in lipid droplets under physiological growth conditions in procyclic T. brucei. β-oxidation has been suggested as a possible catabolic pathway for lipids in T. brucei. A single candidate gene, TFEα1 with coding capacity for a subunit of the trifunctional enzyme complex was identified. TFEα1 is expressed in procyclic T. brucei and present in glycosomal proteomes, Unexpectedly, a TFEα1 gene knock-out mutant still expressed wild-type levels of previously reported NADP-dependent 3-hydroxyacyl-CoA dehydrogenase activity, and therefore, another gene encodes this enzymatic activity. Homozygous Δtfeα1/Δtfeα1 null mutant cells show a normal growth rate and an unchanged glycosomal proteome in procyclic T. brucei. The decay kinetics of accumulated lipid droplets upon oleate withdrawal can be fully accounted for by the dilution effect of cell division in wild-type and Δtfeα1/Δtfeα1 cells. The absence of net catabolism of stored TAG in procyclic T. brucei, even under strictly glucose-free conditions, does not formally exclude a flux through TAG, in which biosynthesis equals catabolism. Also, the possibility remains that TAG catabolism is completely repressed by other carbon sources in culture media or developmentally activated in post-procyclic stages in the tsetse.
Collapse
|
48
|
Deramchia K, Morand P, Biran M, Millerioux Y, Mazet M, Wargnies M, Franconi JM, Bringaud F. Contribution of pyruvate phosphate dikinase in the maintenance of the glycosomal ATP/ADP balance in the Trypanosoma brucei procyclic form. J Biol Chem 2014; 289:17365-78. [PMID: 24794874 DOI: 10.1074/jbc.m114.567230] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trypanosoma brucei belongs to a group of protists that sequester the first six or seven glycolytic steps inside specialized peroxisomes, named glycosomes. Because of the glycosomal membrane impermeability to nucleotides, ATP molecules consumed by the first glycolytic steps need to be regenerated in the glycosomes by kinases, such as phosphoenolpyruvate carboxykinase (PEPCK). The glycosomal pyruvate phosphate dikinase (PPDK), which reversibly converts phosphoenolpyruvate into pyruvate, could also be involved in this process. To address this question, we analyzed the metabolism of the main carbon sources used by the procyclic trypanosomes (glucose, proline, and threonine) after deletion of the PPDK gene in the wild-type (Δppdk) and PEPCK null (Δppdk/Δpepck) backgrounds. The rate of acetate production from glucose is 30% reduced in the Δppdk mutant, whereas threonine-derived acetate production is not affected, showing that PPDK function in the glycolytic direction with production of ATP in the glycosomes. The Δppdk/Δpepck mutant incubated in glucose as the only carbon source showed a 3.8-fold reduction of the glycolytic rate compared with the Δpepck mutant, as a consequence of the imbalanced glycosomal ATP/ADP ratio. The role of PPDK in maintenance of the ATP/ADP balance was confirmed by expressing the glycosomal phosphoglycerate kinase (PGKC) in the Δppdk/Δpepck cell line, which restored the glycolytic flux. We also observed that expression of PGKC is lethal for procyclic trypanosomes, as a consequence of ATP depletion, due to glycosomal relocation of cytosolic ATP production. This illustrates the key roles played by glycosomal and cytosolic kinases, including PPDK, to maintain the cellular ATP/ADP homeostasis.
Collapse
Affiliation(s)
- Kamel Deramchia
- From the Centre de Résonance Magnétique des Systèmes Biologiques, Université de Bordeaux, CNRS UMR-5536, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Pauline Morand
- From the Centre de Résonance Magnétique des Systèmes Biologiques, Université de Bordeaux, CNRS UMR-5536, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Marc Biran
- From the Centre de Résonance Magnétique des Systèmes Biologiques, Université de Bordeaux, CNRS UMR-5536, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Yoann Millerioux
- From the Centre de Résonance Magnétique des Systèmes Biologiques, Université de Bordeaux, CNRS UMR-5536, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Muriel Mazet
- From the Centre de Résonance Magnétique des Systèmes Biologiques, Université de Bordeaux, CNRS UMR-5536, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Marion Wargnies
- From the Centre de Résonance Magnétique des Systèmes Biologiques, Université de Bordeaux, CNRS UMR-5536, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Jean-Michel Franconi
- From the Centre de Résonance Magnétique des Systèmes Biologiques, Université de Bordeaux, CNRS UMR-5536, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Frédéric Bringaud
- From the Centre de Résonance Magnétique des Systèmes Biologiques, Université de Bordeaux, CNRS UMR-5536, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| |
Collapse
|
49
|
Handling uncertainty in dynamic models: the pentose phosphate pathway in Trypanosoma brucei. PLoS Comput Biol 2013; 9:e1003371. [PMID: 24339766 PMCID: PMC3854711 DOI: 10.1371/journal.pcbi.1003371] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 10/16/2013] [Indexed: 01/12/2023] Open
Abstract
Dynamic models of metabolism can be useful in identifying potential drug targets, especially in unicellular organisms. A model of glycolysis in the causative agent of human African trypanosomiasis, Trypanosoma brucei, has already shown the utility of this approach. Here we add the pentose phosphate pathway (PPP) of T. brucei to the glycolytic model. The PPP is localized to both the cytosol and the glycosome and adding it to the glycolytic model without further adjustments leads to a draining of the essential bound-phosphate moiety within the glycosome. This phosphate “leak” must be resolved for the model to be a reasonable representation of parasite physiology. Two main types of theoretical solution to the problem could be identified: (i) including additional enzymatic reactions in the glycosome, or (ii) adding a mechanism to transfer bound phosphates between cytosol and glycosome. One example of the first type of solution would be the presence of a glycosomal ribokinase to regenerate ATP from ribose 5-phosphate and ADP. Experimental characterization of ribokinase in T. brucei showed that very low enzyme levels are sufficient for parasite survival, indicating that other mechanisms are required in controlling the phosphate leak. Examples of the second type would involve the presence of an ATP:ADP exchanger or recently described permeability pores in the glycosomal membrane, although the current absence of identified genes encoding such molecules impedes experimental testing by genetic manipulation. Confronted with this uncertainty, we present a modeling strategy that identifies robust predictions in the context of incomplete system characterization. We illustrate this strategy by exploring the mechanism underlying the essential function of one of the PPP enzymes, and validate it by confirming the model predictions experimentally. Mathematical models have been valuable tools for investigating the complex behaviors of metabolism. Due to incomplete knowledge of biological systems, these models contain inevitable uncertainty. This uncertainty is present in the measured or estimated parameter values, but also in the structure of the metabolic network. In this paper we increase the coverage of a particularly well studied model of glucose metabolism in Trypanosoma brucei, a tropical parasite that causes African sleeping sickness, by extending it with an additional pathway in two compartments. During this modeling process we highlighted uncertainties in parameter values and network structure and used these to formulate new hypotheses which were subsequently tested experimentally. The models were improved with the experimentally derived data, but uncertainty remained concerning the exact topology of the system. These models allowed us to investigate the effects of the loss of one enzyme, 6-phosphogluconate dehydrogenase. By taking uncertainty into account, the models demonstrated that the loss of this enzyme is lethal to the parasite by a mechanism different than that in other organisms. Our methodology shows how formally introducing uncertainty into model building provides robust model behavior that is independent of the network structure or parameter values.
Collapse
|
50
|
Berg M, Vanaerschot M, Jankevics A, Cuypers B, Maes I, Mukherjee S, Khanal B, Rijal S, Roy S, Opperdoes F, Breitling R, Dujardin JC. Metabolic adaptations of Leishmania donovani in relation to differentiation, drug resistance, and drug pressure. Mol Microbiol 2013; 90:428-42. [PMID: 24020363 DOI: 10.1111/mmi.12374] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2013] [Indexed: 12/31/2022]
Abstract
Antimonial (sodium stibogluconate, SSG) resistance and differentiation have been shown to be closely linked in Leishmania donovani, with SSG-resistant strains showing an increased capacity to generate infectious (metacyclic) forms. This is the first untargeted LC-MS metabolomics study which integrated both phenomena in one experimental design and provided insights into metabolic differences between three clinical L. donovani strains with a similar genetic background but different SSG-susceptibilities. We performed this analysis at different stages during promastigote growth and in the absence or presence of drug pressure. When comparing SSG-resistant and SSG-sensitive strains, a number of metabolic changes appeared to be constitutively present in all growth stages, pointing towards a clear link with SSG-resistance, whereas most metabolic changes were only detected in the stationary stage. These changes reflect the close intertwinement between SSG-resistance and an increased metacyclogenesis in resistant parasites. The metabolic changes suggest that SSG-resistant parasites have (i) an increased capacity for protection against oxidative stress; (ii) a higher fluidity of the plasma membrane; and (iii) a metabolic survival kit to better endure infection. These changes were even more pronounced in a resistant strain kept under Sb(III) drug pressure.
Collapse
Affiliation(s)
- Maya Berg
- Unit of Molecular Parasitology, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|