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Rojas-Pirela M, Delgado A, Rondón-Guerrero YDC, Cáceres AJ, Michels PAM, Concepción JL, Quiñones W. A Trypanosoma cruzi phosphoglycerate kinase isoform with a Per-Arnt-Sim domain acts as a possible sensor for intracellular conditions. Exp Parasitol 2023:108574. [PMID: 37353138 DOI: 10.1016/j.exppara.2023.108574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/15/2023] [Accepted: 06/20/2023] [Indexed: 06/25/2023]
Abstract
Per-ARNT-Sim (PAS) domains constitute a family of domains present in a wide variety of prokaryotic and eukaryotic organisms. They form part of the structure of various proteins involved in diverse cellular processes. Regulation of enzymatic activity and adaptation to environmental conditions, by binding small ligands, are the main functions attributed to PAS-containing proteins. Recently, genes for a diverse set of proteins with a PAS domain were identified in the genomes of several protists belonging to the group of kinetoplastids, however, until now few of these proteins have been characterized. In this work, we characterize a phosphoglycerate kinase containing a PAS domain present in Trypanosoma cruzi (TcPAS-PGK). This PGK isoform is an active enzyme of 58 kDa with a PAS domain located at its N-terminal end. We identified the protein's localization within glycosomes of the epimastigote form of the parasite by differential centrifugation and selective permeabilization of its membranes with digitonin, as well as in an enriched mitochondrial fraction. Heterologous expression systems were developed for the protein with the N-terminal PAS domain (PAS-PGKc) and without it (PAS-PGKt), and the substrate affinities of both forms of the protein were determined. The enzyme does not exhibit standard Michaelis-Menten kinetics. When evaluating the dependence of the specific activity of the recombinant PAS-PGK on the concentration of its substrates 3-phosphoglycerate (3PGA) and ATP, two peaks of maximal activity were found for the complete enzyme with the PAS domain and a single peak for the enzyme without the domain. Km values measured for 3PGA were 219 ± 26 and 8.8 ± 1.3 μM, and for ATP 291 ± 15 and 38 ± 2.2 μM, for the first peak of PAS-PGKc and for PAS-PGKt, respectively, whereas for the second PAS-PGKc peak values of approximately 1.1-1.2 mM were estimated for both substrates. Both recombinant proteins show inhibition by high concentrations of their substrates, ATP and 3PGA. The presence of hemin and FAD exerts a stimulatory effect on PAS-PGKc, increasing the specific activity by up to 55%. This stimulation is not observed in the absence of the PAS domain. It strongly suggests that the PAS domain has an important function in vivo in T. cruzi in the modulation of the catalytic activity of this PGK isoform. In addition, the PAS-PGK through its PAS and PGK domains could act as a sensor for intracellular conditions in the parasite to adjust its intermediary metabolism.
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Affiliation(s)
- Maura Rojas-Pirela
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela
| | - Andrea Delgado
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela
| | - Yossmayer D C Rondón-Guerrero
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela
| | - Ana J Cáceres
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela
| | - Paul A M Michels
- School of Biological Sciences, The University of Edinburgh, The King's Buildings, Edinburgh, EH9 3FL, Scotland, United Kingdom
| | - Juan Luis Concepción
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela
| | - Wilfredo Quiñones
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela.
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Krishna CK, Franke L, Erdmann R, Kalel VC. Isolation of Glycosomes from Trypanosoma brucei. Methods Mol Biol 2023; 2643:33-45. [PMID: 36952176 DOI: 10.1007/978-1-0716-3048-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
Glycosomes, belonging to the sub-class of peroxisomes, are single-membrane-bound organelles of trypanosomatid parasites. Glycosomes compartmentalize mainly glycolytic and other essential metabolic pathways such as gluconeogenesis, pentose phosphate pathway, sugar nucleotide biosynthesis, etc. Since glycosomes are parasite-specific and their biogenesis is essential for the parasite survival, they have attracted a lot of interest over the years. Understanding the glycosomal enzyme composition and machinery involved in the biogenesis of this organelle requires the knowledge of the glycosomal proteome. Here we describe a method to isolate highly purified glycosomes and further enrichment of the glycosomal membrane proteins from the pro-cyclic form of Trypanosoma brucei. The isolation method is based on the controlled rupture of the cells by silicon carbide, followed by the differential centrifugation, and density gradient centrifugation. Further, the glycosomal membrane proteins are enriched from the purified glycosomes by the successive treatments with low-salt, high-salt, and alkaline carbonate buffer extractions.
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Affiliation(s)
- Chethan K Krishna
- Institute for Biochemistry and Pathobiochemistry, Department of Systems Biochemistry, Faculty of Medicine, Ruhr University of Bochum, Bochum, Germany
| | - Laura Franke
- Institute for Biochemistry and Pathobiochemistry, Department of Systems Biochemistry, Faculty of Medicine, Ruhr University of Bochum, Bochum, Germany
| | - Ralf Erdmann
- Institute for Biochemistry and Pathobiochemistry, Department of Systems Biochemistry, Faculty of Medicine, Ruhr University of Bochum, Bochum, Germany.
| | - Vishal C Kalel
- Institute for Biochemistry and Pathobiochemistry, Department of Systems Biochemistry, Faculty of Medicine, Ruhr University of Bochum, Bochum, Germany.
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Furtado RR, Soares DC, Prado AF, Farias LHS, Da Silva BJM, Rodrigues APD, Silva EO. Constitutive nitric oxide synthase-like enzyme in two species involved in cutaneous and mucocutaneous leishmaniasis. Parasitol Int 2021; 83:102347. [PMID: 33862253 DOI: 10.1016/j.parint.2021.102347] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 04/09/2021] [Accepted: 04/09/2021] [Indexed: 11/21/2022]
Abstract
Leishmania is an obligate intracellular parasite that primarily inhabits macrophages. The destruction of the parasite in the host cell is a fundamental mechanism for infection control. In addition, inhibition of the leishmanicidal activity of macrophages seems to be related to the ability of some species to inhibit the production of nitric oxide (NO) by depleting arginine. Some species of Leishmania have the ability to produce NO from a constitutive nitric oxide synthase-like enzyme (cNOS-like). However, the localization of cNOS-like in Leishmania has not been described before. As such, this study was designed to locate cNOS-like enzyme and NO production in promastigotes of Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis. NO production was initially quantified by flow cytometry, which indicated a significant difference in NO production between L. (L.) amazonensis (GMFC = 92.17 +/- 4.6) and L. (V.) braziliensis (GMFC = 18.89 +/- 2.29) (P < 0.05). Analysis of cNOS expression by immunoblotting showed more expression in L. (L.) amazonensis versus L. (V.) braziliensis. Subsequently, cNOS-like immunolabeling was observed in promastigotes in regions near vesicles, the flagellar pocket and mitochondria, and small clusters of particles appeared to be fusing with vesicles suggestive of glycosomes, peroxisome-like-organelles that compartmentalize the glycolytic pathway in trypanosomatid parasites. In addition, confocal microscopy analysis demonstrated colocalization of cNOS-like and GAPDH, a specific marker for glycosomes. Thus, L. (L.) amazonensis produces greater amounts of NO than L. (V.) braziliensis, and both species present the cNOS-like enzyme inside glycosomes.
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González-Marcano E, Acosta H, Quiñones W, Mijares A, Concepción JL. Hysteresis of pyruvate phosphate dikinase from Trypanosoma cruzi. Parasitol Res 2021; 120:1421-8. [PMID: 33098461 DOI: 10.1007/s00436-020-06934-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [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.
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Castro H, Rocha MI, Silva R, Oliveira F, Gomes-Alves AG, Cruz T, Duarte M, Tomás AM. Functional insight into the glycosomal peroxiredoxin of Leishmania. Acta Trop 2020; 201:105217. [PMID: 31605692 DOI: 10.1016/j.actatropica.2019.105217] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/11/2019] [Accepted: 10/08/2019] [Indexed: 01/22/2023]
Abstract
Glycosomes of trypanosomatids are peroxisome-like organelles comprising unique metabolic features, among which the lack of the hallmark peroxisomal enzyme catalase. The absence of this highly efficient peroxidase from glycosomes is presumably compensated by other antioxidants, peroxidases of the peroxiredoxin (PRX) family being the most promising candidates for this function. Here, we follow on this premise and investigate the product of a Leishmania infantum gene coding for a putative glycosomal PRX (LigPRX). First, we demonstrate that LigPRX localizes to glycosomes, resorting to indirect immunofluorescence analysis. Second, we prove that purified recombinant LigPRX is an active peroxidase in vitro. Third, we generate viable LigPRX-depleted L. infantum promastigotes by classical homologous recombination. Surprisingly, phenotypic analysis of these knockout parasites revealed that promastigote survival, replication, and protection from oxidative and nitrosative insults can proceed normally in the absence of LigPRX. Noticeably, we also witness that LigPRX-depleted parasites can infect and thrive in mice to the same extent as wild type parasites. Overall, by disclosing the dispensable character of the glycosomal peroxiredoxin in L. infantum, this work excludes this enzyme from being a key component of the glycosomal hydroperoxide metabolism and contemplates alternative players for this function.
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Affiliation(s)
- Helena Castro
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal.
| | - Maria Inês Rocha
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Ricardo Silva
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Filipe Oliveira
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Ana Georgina Gomes-Alves
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Tânia Cruz
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Margarida Duarte
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Ana Maria Tomás
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
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Acosta H, Burchmore R, Naula C, Gualdrón-López M, Quintero-Troconis E, Cáceres AJ, Michels PAM, Concepción JL, Quiñones W. Proteomic analysis of glycosomes from Trypanosoma cruzi epimastigotes. Mol Biochem Parasitol 2019; 229:62-74. [PMID: 30831156 PMCID: PMC7082770 DOI: 10.1016/j.molbiopara.2019.02.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/25/2019] [Accepted: 02/27/2019] [Indexed: 12/20/2022]
Abstract
In Trypanosoma cruzi, the causal agent of Chagas disease, the first seven steps of glycolysis are compartmentalized in glycosomes, which are authentic but specialized peroxisomes. Besides glycolysis, activity of enzymes of other metabolic processes have been reported to be present in glycosomes, such as β-oxidation of fatty acids, purine salvage, pentose-phosphate pathway, gluconeogenesis and biosynthesis of ether-lipids, isoprenoids, sterols and pyrimidines. In this study, we have purified glycosomes from T. cruzi epimastigotes, collected the soluble and membrane fractions of these organelles, and separated peripheral and integral membrane proteins by Na2CO3 treatment and osmotic shock. Proteomic analysis was performed on each of these fractions, allowing us to confirm the presence of enzymes involved in various metabolic pathways as well as identify new components of this parasite's glycosomes.
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Affiliation(s)
- Héctor Acosta
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela
| | - Richard Burchmore
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Christina Naula
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Melisa Gualdrón-López
- Instituto Salud Global, Hospital Clinic-Universitat de Barcelona, and Institute for Health Sciences Trias i Pujol, Barcelona, Spain
| | - Ender Quintero-Troconis
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela
| | - Ana J Cáceres
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela
| | - Paul A M Michels
- Centre for Immunity, Infection and Evolution and Centre for Translational and Chemical Biology, The University of Edinburgh, Edinburgh, EH9 3FL, UK
| | - Juan Luis Concepción
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela
| | - Wilfredo Quiñones
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela.
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Lee S, Cheung-See-Kit M, Williams TA, Yamout N, Zufferey R. The glycosomal alkyl-dihydroxyacetonephosphate synthase TbADS is essential for the synthesis of ether glycerophospholipids in procyclic trypanosomes. Exp Parasitol 2018; 185:71-78. [PMID: 29355496 DOI: 10.1016/j.exppara.2018.01.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 12/30/2017] [Accepted: 01/14/2018] [Indexed: 01/15/2023]
Abstract
Glycerophospholipids are the main constituents of the biological membranes in Trypanosoma brucei, which causes sleeping sickness in humans. The present work reports the characterization of the alkyl-dihydroxyacetonephosphate synthase TbADS that catalyzes the committed step in ether glycerophospholipid biosynthesis. TbADS localizes to the glycosomal lumen. TbADS complemented a null mutant of Leishmania major lacking alkyl-dihydroxyacetonephosphate synthase activity and restored the formation of normal form of the ether lipid based virulence factor lipophosphoglycan. Despite lacking alkyl-dihydroxyacetonephosphate synthase activity, a null mutant of TbADS in procyclic trypanosomes remained viable and exhibited normal growth. Comprehensive analysis of cellular glycerophospholipids showed that TbADS was involved in the biosynthesis of all ether glycerophospholipid species, primarily found in the PE and PC classes.
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Affiliation(s)
- Sungsu Lee
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
| | - Melanie Cheung-See-Kit
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
| | - Tyler A Williams
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
| | - Nader Yamout
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
| | - Rachel Zufferey
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA.
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Rojas-Pirela M, Rigden DJ, Michels PA, Cáceres AJ, Concepción JL, Quiñones W. Structure and function of Per-ARNT-Sim domains and their possible role in the life-cycle biology of Trypanosoma cruzi. Mol Biochem Parasitol 2017; 219:52-66. [PMID: 29133150 DOI: 10.1016/j.molbiopara.2017.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 10/12/2017] [Accepted: 11/02/2017] [Indexed: 02/07/2023]
Abstract
Per-ARNT-Sim (PAS) domains of proteins play important roles as modules for signalling and cellular regulation processes in widely diverse organisms such as Archaea, Bacteria, protists, plants, yeasts, insects and vertebrates. These domains are present in many proteins where they are used as sensors of stimuli and modules for protein interactions. Characteristically, they can bind a broad spectrum of molecules. Such binding causes the domain to trigger a specific cellular response or to make the protein containing the domain susceptible to responding to additional physical or chemical signals. Different PAS proteins have the ability to sense redox potential, light, oxygen, energy levels, carboxylic acids, fatty acids and several other stimuli. Such proteins have been found to be involved in cellular processes such as development, virulence, sporulation, adaptation to hypoxia, circadian cycle, metabolism and gene regulation and expression. Our analysis of the genome of different kinetoplastid species revealed the presence of PAS domains also in different predicted kinases from these protists. Open-reading frames coding for these PAS-kinases are unusually large. In addition, the products of these genes appear to contain in their structure combinations of domains uncommon in other eukaryotes. The physiological significance of PAS domains in these parasites, specifically in Trypanosoma cruzi, is discussed.
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Affiliation(s)
- Maura Rojas-Pirela
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Daniel J Rigden
- Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
| | - Paul A Michels
- Centre for Immunity, Infection and Evolution and Centre for Translational and Chemical Biology, School of Biological Sciences, The University of Edinburgh, The King's Buildings, Edinburgh EH9 3FL, Scotland, United Kingdom
| | - Ana J Cáceres
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Juan Luis Concepción
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Wilfredo Quiñones
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela.
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Banerjee H, Rachubinski RA. Involvement of SNARE protein Ykt6 in glycosome biogenesis in Trypanosoma brucei. Mol Biochem Parasitol 2017; 218:28-37. [PMID: 29107734 DOI: 10.1016/j.molbiopara.2017.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 10/02/2017] [Accepted: 10/21/2017] [Indexed: 11/30/2022]
Abstract
The kinetoplastid parasites Trypanosoma and Leishmania are etiologic agents of diseases like African sleeping sickness, Chagas and leishmaniasis that inflict many tropical and subtropical parts of the world. These parasites are distinctive in that they compartmentalize most of the usually cytosolic enzymes of the glycolytic pathway within a peroxisome-like organelle called the glycosome. Functional glycosomes are essential in both the procyclic and bloodstream forms of trypanosomatid parasites, and mislocalization of glycosomal enzymes to the cytosol is fatal for the parasite. The life cycle of these parasites is intimately linked to their efficient protein and vesicular trafficking machinery that helps them in immune evasion, host-pathogen interaction and organelle biogenesis and integrity. Soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins play important roles in vesicular trafficking and mediate a wide range of protein-protein interactions in eukaryotes. We show here that the SNARE protein Ykt6 is necessary for glycosome biogenesis and function in Trypanosoma brucei. RNAi-mediated depletion of Ykt6 in both the procyclic and bloodstream forms of T. brucei leads to mislocalization of glycosomal matrix proteins to the cytosol, pronounced reduction in glycosome number, and cell death. GFP-tagged Ykt6 appears as punctate structures in the T. brucei cell and colocalizes in part to glycosomes. Our results constitute the first demonstration of a role for SNARE proteins in the biogenesis of peroxisomal organelles.
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Affiliation(s)
- Hiren Banerjee
- Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Richard A Rachubinski
- Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada.
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Rondón-Mercado R, Acosta H, Cáceres AJ, Quiñones W, Concepción JL. Subcellular localization of glycolytic enzymes and characterization of intermediary metabolism of Trypanosoma rangeli. Mol Biochem Parasitol 2017. [PMID: 28645481 DOI: 10.1016/j.molbiopara.2017.06.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Trypanosoma rangeli is a hemoflagellate protist that infects wild and domestic mammals as well as humans in Central and South America. Although this parasite is not pathogenic for human, it is being studied because it shares with Trypanosoma cruzi, the etiological agent of Chagas' disease, biological characteristics, geographic distribution, vectors and vertebrate hosts. Several metabolic studies have been performed with T. cruzi epimastigotes, however little is known about the metabolism of T. rangeli. In this work we present the subcellular distribution of the T. rangeli enzymes responsible for the conversion of glucose to pyruvate, as determined by epifluorescense immunomicroscopy and subcellular fractionation involving either selective membrane permeabilization with digitonin or differential and isopycnic centrifugation. We found that in T. rangeli epimastigotes the first six enzymes of the glycolytic pathway, involved in the conversion of glucose to 1,3-bisphosphoglycerate are located within glycosomes, while the last four steps occur in the cytosol. In contrast with T. cruzi, where three isoenzymes (one cytosolic and two glycosomal) of phosphoglycerate kinase are expressed simultaneously, only one enzyme with this activity is detected in T. rangeli epimastigotes, in the cytosol. Consistent with this latter result, we found enzymes involved in auxiliary pathways to glycolysis needed to maintain adenine nucleotide and redox balances within glycosomes such as phosphoenolpyruvate carboxykinase, malate dehydrogenase, fumarate reductase, pyruvate phosphate dikinase and glycerol-3-phosphate dehydrogenase. Glucokinase, galactokinase and the first enzyme of the pentose-phosphate pathway, glucose-6-phosphate dehydrogenase, were also located inside glycosomes. Furthermore, we demonstrate that T. rangeli epimastigotes growing in LIT medium only consume glucose and do not excrete ammonium; moreover, they are unable to survive in partially-depleted glucose medium. The velocity of glucose consumption is about 40% higher than that of procyclic Trypanosoma brucei, and four times faster than by T. cruzi epimastigotes under the same culture conditions.
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Affiliation(s)
- Rocío Rondón-Mercado
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Héctor Acosta
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Ana J Cáceres
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Wilfredo Quiñones
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Juan Luis Concepción
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela.
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Wang X, Inaoka DK, Shiba T, Balogun EO, Allmann S, Watanabe YI, Boshart M, Kita K, Harada S. Expression, purification, and crystallization of type 1 isocitrate dehydrogenase from Trypanosoma brucei brucei. Protein Expr Purif 2017; 138:56-62. [PMID: 28642005 DOI: 10.1016/j.pep.2017.06.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Isocitrate dehydrogenases (IDHs) are metabolic enzymes that catalyze the oxidative decarboxylation of isocitrate to α-ketoglutarate. Depending on the electron acceptor and subcellular localization, these enzymes are classified as NADP+-dependent IDH1 in the cytosol or peroxisomes, NADP+-dependent IDH2 and NAD+-dependent IDH3 in mitochondria. Trypanosoma brucei is a protozoan parasite that causes African sleeping sickness in humans and Nagana disease in animals. Here, for the first time, a putative glycosomal T. brucei type 1 IDH (TbIDH1) was expressed in Escherichia coli and purified for crystallographic study. Surprisingly, the putative NADP+-dependent TbIDH1 has higher activity with NAD+ compared with NADP+ as electron acceptor, a unique characteristic among known eukaryotic IDHs which encouraged us to crystallize TbIDH1 for future biochemical and structural studies. Methods of expression and purification of large amounts of recombinant TbIDH1 with improved solubility to facilitate protein crystallization are presented.
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12
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Allmann S, Bringaud F. Glycosomes: A comprehensive view of their metabolic roles in T. brucei. Int J Biochem Cell Biol 2017; 85:85-90. [PMID: 28179189 DOI: 10.1016/j.biocel.2017.01.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 01/27/2017] [Accepted: 01/29/2017] [Indexed: 11/28/2022]
Abstract
Peroxisomes are single-membrane cellular organelles, present in most eukaryotic cells and organisms from human to yeast, fulfilling essential metabolic functions in lipid metabolism, free radical detoxification, differentiation, development, morphogenesis, etc. Interestingly, the protozoan parasite species Trypanosoma contains peroxisome-like organelles named glycosomes, which lack hallmark peroxisomal pathways and enzymes, such as catalase. Glycosomes are the only peroxisome-like organelles containing most enzymatic steps of the glycolytic pathway as well as enzymes of pyrimidine biosynthesis, purine salvage and biosynthesis of nucleotide sugars. We present here an overview of the glycosomal metabolic peculiarities together with the current view of the raison d'être of this unique metabolic peroxisomal sequestration.
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Affiliation(s)
- Stefan Allmann
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France
| | - Frédéric Bringaud
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, Bordeaux, France.
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13
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Hughes L, Borrett S, Towers K, Starborg T, Vaughan S. Patterns of organelle ontogeny through a cell cycle revealed by whole-cell reconstructions using 3D electron microscopy. J Cell Sci 2017; 130:637-647. [PMID: 28049718 DOI: 10.1242/jcs.198887] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 12/01/2016] [Indexed: 12/29/2022] Open
Abstract
The major mammalian bloodstream form of the African sleeping sickness parasite Trypanosoma brucei multiplies rapidly, and it is important to understand how these cells divide. Organelle inheritance involves complex spatiotemporal re-arrangements to ensure correct distribution to daughter cells. Here, serial block face scanning electron microscopy (SBF-SEM) was used to reconstruct whole individual cells at different stages of the cell cycle to give an unprecedented temporal, spatial and quantitative view of organelle division, inheritance and abscission in a eukaryotic cell. Extensive mitochondrial branching occurred only along the ventral surface of the parasite, but the mitochondria returned to a tubular form during cytokinesis. Fission of the mitochondrion occurred within the cytoplasmic bridge during the final stage of cell division, correlating with cell abscission. The nuclei were located underneath each flagellum at mitosis and the mitotic spindle was located along the ventral surface, further demonstrating the asymmetric arrangement of cell cleavage in trypanosomes. Finally, measurements demonstrated that multiple Golgi bodies were accurately positioned along the flagellum attachment zone, suggesting a mechanism for determining the location of Golgi bodies along each flagellum during the cell cycle.
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Affiliation(s)
- Louise Hughes
- Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Samantha Borrett
- Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Katie Towers
- Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Oxford OX3 0BP, UK
| | - Tobias Starborg
- Wellcome Centre for Cell Matrix Research, University of Manchester, Michael Smith Building, Manchester M13 9PT, UK
| | - Sue Vaughan
- Department of Biological and Medical Sciences, Faculty of Health and Life Science, Oxford Brookes University, Oxford OX3 0BP, UK
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Watanabe Y, Kawaguchi K, Saito S, Okabe T, Yonesu K, Egashira S, Kameya M, Morita M, Kashiwayama Y, Imanaka T. An HTRF based high-throughput screening for discovering chemical compounds that inhibit the interaction between Trypanosoma brucei Pex5p and Pex14p. Biochem Biophys Rep 2016; 6:260-265. [PMID: 28955883 PMCID: PMC5600434 DOI: 10.1016/j.bbrep.2016.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 04/12/2016] [Accepted: 05/06/2016] [Indexed: 11/16/2022] Open
Abstract
The glycosome, a peroxisome-related organelle, is essential for the growth and survival of trypanosomatid protozoa. In glycosome biogenesis, Pex5p recognizes newly synthesized glycosomal matrix proteins via peroxisome-targeting signal type-1 (PTS-1) and transports them into glycosomes through an interaction with Pex14p, a component of the matrix protein import machinery on the glycosomal membrane. Knockdown of the PEX5 or PEX14 with RNAi has been shown to inhibit the growth of Trypanosoma brucei. Thus, compounds that inhibit the interaction of TbPex5p–TbPex14p are expected to become lead compounds in the development of anti-trypanosomal drugs. Here, we report a homogenous time-resolved fluorescence (HTRF) assay for the screening of compounds that inhibit the TbPex5p–TbPex14p interaction. The binding of GST-TbPex14p and TbPex5p-His with or without additional compounds was evaluated by measuring the energy transfer of the HTRF pair, using a terbium-labeled anti GST antibody as the donor and an FITC-labeled anti His antibody as the acceptor. The assay was performed in a 384-well plate platform and exhibits a Z’-factor of 0.85–0.91, while the coefficiency of variation is 1.1–7.7%, suggesting it can be readily adapted to a high-throughput format for the automated screening of chemical libraries. We screened 20,800 compounds and found 11 compounds that inhibited energy transfer. Among them, in a pull-down assay one compound exhibited selective inhibition of TbPex5p–TbPex14p without any HsPex5p–HsPex14p interaction. An HTRF-based TbPex5p–TbPex14p interaction assay system was established. A compound was found that selectively inhibits the TbPex5p–TbPex14p interaction. This system is applicable for drug discovery against other glycosomal proteins.
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Affiliation(s)
- Yuichi Watanabe
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Kosuke Kawaguchi
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Syuken Saito
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Takayoshi Okabe
- Drug Discovery Initiative, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kiyoaki Yonesu
- Drug Discovery Initiative, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shinichiro Egashira
- Drug Discovery Initiative, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masafumi Kameya
- Biotechnology Research Center and Department of Biotechnology, Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan
| | - Masashi Morita
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Yoshinori Kashiwayama
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
| | - Tsuneo Imanaka
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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.
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Rivero LA, Concepción JL, Quintero-Troconis E, Quiñones W, Michels PA, Acosta H. Trypanosoma evansi contains two auxiliary enzymes of glycolytic metabolism: Phosphoenolpyruvate carboxykinase and pyruvate phosphate dikinase. Exp Parasitol 2016; 165:7-15. [PMID: 26968775 DOI: 10.1016/j.exppara.2016.03.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 02/11/2016] [Accepted: 03/03/2016] [Indexed: 11/22/2022]
Abstract
Trypanosoma evansi is a monomorphic protist that can infect horses and other animal species of economic importance for man. Like the bloodstream form of the closely related species Trypanosoma brucei, T. evansi depends exclusively on glycolysis for its free-energy generation. In T. evansi as in other kinetoplastid organisms, the enzymes of the major part of the glycolytic pathway are present within organelles called glycosomes, which are authentic but specialized peroxisomes. Since T. evansi does not undergo stage-dependent differentiations, it occurs only as bloodstream forms, it has been assumed that the metabolic pattern of this parasite is identical to that of the bloodstream form of T. brucei. However, we report here the presence of two additional enzymes, phosphoenolpyruvate carboxykinase and PPi-dependent pyruvate phosphate dikinase in T. evansi glycosomes. Their colocalization with glycolytic enzymes within the glycosomes of this parasite has not been reported before. Both enzymes can make use of PEP for contributing to the production of ATP within the organelles. The activity of these enzymes in T. evansi glycosomes drastically changes the model assumed for the oxidation of glucose by this parasite.
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17
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Kalel VC, Schliebs W, Erdmann R. Identification and functional characterization of Trypanosoma brucei peroxin 16. Biochim Biophys Acta 2015; 1853:2326-37. [PMID: 26025675 DOI: 10.1016/j.bbamcr.2015.05.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 05/22/2015] [Accepted: 05/24/2015] [Indexed: 12/01/2022]
Abstract
Protozoan parasites of the family Trypanosomatidae infect humans as well as livestock causing devastating diseases like sleeping sickness, Chagas disease, and Leishmaniasis. These parasites compartmentalize glycolytic enzymes within unique organelles, the glycosomes. Glycosomes represent a subclass of peroxisomes and they are essential for the parasite survival. Hence, disruption of glycosome biogenesis is an attractive drug target for these Neglected Tropical Diseases (NTDs). Peroxin 16 (PEX16) plays an essential role in peroxisomal membrane protein targeting and de novo biogenesis of peroxisomes from endoplasmic reticulum (ER). We identified trypanosomal PEX16 based on specific sequence characteristics and demonstrate that it is an integral glycosomal membrane protein of procyclic and bloodstream form trypanosomes. RNAi mediated partial knockdown of Trypanosoma brucei PEX16 in bloodstream form trypanosomes led to severe ATP depletion, motility defects and cell death. Microscopic and biochemical analysis revealed drastic reduction in glycosome number and mislocalization of the glycosomal matrix enzymes to the cytosol. Asymmetry of the localization of the remaining glycosomes was observed with a severe depletion in the posterior part. The results demonstrate that trypanosomal PEX16 is essential for glycosome biogenesis and thereby, provides a potential drug target for sleeping sickness and related diseases.
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Affiliation(s)
- Vishal C Kalel
- Department of Systems Biochemistry, Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr-University Bochum, Germany
| | - Wolfgang Schliebs
- Department of Systems Biochemistry, Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr-University Bochum, Germany
| | - Ralf Erdmann
- Department of Systems Biochemistry, Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr-University Bochum, Germany.
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18
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Acosta H, Cáceres A, González-Marcano E, Quiñones W, Avilán L, Dubourdieu M, Concepción JL. Hysteresis and positive cooperativity as possible regulatory mechanisms of Trypanosoma cruzi hexokinase activity. Mol Biochem Parasitol 2015; 198:82-91. [PMID: 25683029 DOI: 10.1016/j.molbiopara.2015.01.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 01/27/2015] [Accepted: 01/29/2015] [Indexed: 10/24/2022]
Abstract
In Trypanosoma cruzi, the causal agent of Chagas disease, the first six or seven steps of glycolysis are compartmentalized in glycosomes, which are authentic but specialized peroxisomes. Hexokinase (HK), the first enzyme in the glycolytic pathway, has been an important research object, particularly as a potential drug target. Here we present the results of a specific kinetics study of the native HK from T. cruzi epimastigotes; a sigmoidal behavior was apparent when the velocity of the reaction was determined as a function of the concentration of its substrates, glucose and ATP. This behavior was only observed at low enzyme concentration, while at high concentration classical Michaelis-Menten kinetics was displayed. The progress curve of the enzyme's activity displays a lag phase of which the length is dependent on the protein concentration, suggesting that HK is a hysteretic enzyme. The hysteretic behavior may be attributed to slow changes in the conformation of T. cruzi HK as a response to variations of glucose and ATP concentrations in the glycosomal matrix. Variations in HK's substrate concentrations within the glycosomes may be due to variations in the trypanosome's environment. The hysteretic and cooperative behavior of the enzyme may be a form of regulation by which the parasite can more readily adapt to these environmental changes, occurring within each of its hosts, or during the early phase of transition to a new host.
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Affiliation(s)
- Héctor Acosta
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela.
| | - Ana Cáceres
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | | | - Wilfredo Quiñones
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Luisana Avilán
- Laboratorio de Fisiología Animal, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Michel Dubourdieu
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
| | - Juan Luis Concepción
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela
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Rodriguez-Contreras D, Hamilton N. Gluconeogenesis in Leishmania mexicana: contribution of glycerol kinase, phosphoenolpyruvate carboxykinase, and pyruvate phosphate dikinase. J Biol Chem 2014; 289:32989-3000. [PMID: 25288791 DOI: 10.1074/jbc.m114.569434] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Gluconeogenesis is an active pathway in Leishmania amastigotes and is essential for their survival within the mammalian cells. However, our knowledge about this pathway in trypanosomatids is very limited. We investigated the role of glycerol kinase (GK), phosphoenolpyruvate carboxykinase (PEPCK), and pyruvate phosphate dikinase (PPDK) in gluconeogenesis by generating the respective Leishmania mexicana Δgk, Δpepck, and Δppdk null mutants. Our results demonstrated that indeed GK, PEPCK, and PPDK are key players in the gluconeogenesis pathway in Leishmania, although stage-specific differences in their contribution to this pathway were found. GK participates in the entry of glycerol in promastigotes and amastigotes; PEPCK participates in the entry of aspartate in promastigotes, and PPDK is involved in the entry of alanine in amastigotes. Furthermore, the majority of alanine enters into the pathway via decarboxylation of pyruvate in promastigotes, whereas pathway redundancy is suggested for the entry of aspartate in amastigotes. Interestingly, we also found that l-lactate, an abundant glucogenic precursor in mammals, was used by Leishmania amastigotes to synthesize mannogen, entering the pathway through PPDK. On the basis of these new results, we propose a revision in the current model of gluconeogenesis in Leishmania, emphasizing the differences between amastigotes and promastigotes. This work underlines the importance of studying the trypanosomatid intracellular life cycle stages to gain a better understanding of the pathologies caused in humans.
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Affiliation(s)
- Dayana Rodriguez-Contreras
- From the Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon 97239
| | - Nicklas Hamilton
- From the Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, Oregon 97239
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González-Marcano E, Mijares A, Quiñones W, Cáceres A, Concepción JL. Post-translational modification of the pyruvate phosphate dikinase from Trypanosoma cruzi. Parasitol Int 2013; 63:80-6. [PMID: 24060543 DOI: 10.1016/j.parint.2013.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/13/2013] [Accepted: 09/11/2013] [Indexed: 11/18/2022]
Abstract
In kinetoplastids such as Trypanosoma cruzi, glycolysis is compartmentalized in peroxisome-like organelles called glycosomes. Pyruvate phosphate dikinase (PPDK), an auxiliary enzyme of glycolysis, is also located in the glycosomes. We have detected that this protein is post-translationally modified by phosphorylation and proteolytic cleavage. On western blots of T. cruzi epimastigotes, two PPDK forms were found with apparent MW of 100 kDa and 75 kDa, the latter one being phosphorylated at Thr481, a residue present in a highly conserved region. In subcellular localization assays the 75 kDa PPDK was located peripherally at the glycosomal membrane. Both PPDK forms were found in all life-cycle stages of the parasite. When probing for both PPDK forms during a growth of epimastigotes in batch culture, an increase in the level of the 75 kDa form and a decrease of the 100 kDa one were observed by western blot analysis, signifying that glucose starvation and the concomitant switch of the metabolism to amino acid catabolism may play a role in the post-translational processing of the PPDK. Either one or both of the processes, phosphorylation and proteolytic cleavage of PPDK, result in inactivation of the enzyme. It remains to be established whether the phenomenon exerts a regulatory function.
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Affiliation(s)
- Eglys González-Marcano
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, La Hechicera, Mérida 5101, Venezuela.
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