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Ullah W, Wu WF, Malak N, Nasreen N, Swelum AA, Marcelino LA, Niaz S, Khan A, Ben Said M, Chen CC. Computational investigation of turmeric phytochemicals targeting PTR1 enzyme of Leishmania species. Heliyon 2024; 10:e27907. [PMID: 38533011 PMCID: PMC10963314 DOI: 10.1016/j.heliyon.2024.e27907] [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: 09/15/2023] [Revised: 03/06/2024] [Accepted: 03/07/2024] [Indexed: 03/28/2024] Open
Abstract
In this study, we used in silico techniques to identify available parasite treatments, representing a promising therapeutic avenue. Building upon our computational initiatives aimed at discovering natural inhibitors for various target enzymes from parasites causing neglected tropical diseases (NTDs), we present novel findings on three turmeric-derived phytochemicals as inhibitors of Leishmania pteridine reductase I (PTR1) through in silico methodologies. PTR1, a crucial enzyme in the unique folate metabolism of trypanosomatid parasites, holds established therapeutic significance. Employing MOE software, a molecular docking analysis assesses the efficacy of turmeric phytochemicals against Leishmania PTR1. Validation of the docking protocol is confirmed with an RMSD value of 2. Post-docking, compounds displaying notable interactions with critical residues and binding affinities ranging between -6 and -8 kcal/mol are selected for interaction pattern exploration. Testing twelve turmeric phytochemicals, including curcumin, zingiberene, curcumol, curcumenol, eugenol, bisdemethoxycurcumin, tetrahydrocurcumin, tryethylcurcumin, turmerones, turmerin, demethoxycurcumin, and turmeronols, revealed binding affinities ranging from -5.5 to -8 kcal/mol. Notably, curcumin, demethoxycurcumin, and bisdemethoxycurcumin exhibit binding affinities within -6.5 to -8 kcal/mol and establish substantial interactions with catalytic residues. These phytochemicals hold promise as lead structures for rational drug design targeting Leishmania spp. PTR in future applications. This work underscores the potential of these identified phytochemicals in the development of more effective inhibitors, demonstrating their relevance in addressing neglected tropical diseases caused by parasites.
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Affiliation(s)
- Wasia Ullah
- Department of Zoology, Abdul Wali Khan University Mardan, Mardan, 23200, Pakistan
| | - Wen-Feng Wu
- Department of Radiology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, 600, Taiwan
| | - Nosheen Malak
- Department of Zoology, Abdul Wali Khan University Mardan, Mardan, 23200, Pakistan
| | - Nasreen Nasreen
- Department of Zoology, Abdul Wali Khan University Mardan, Mardan, 23200, Pakistan
| | - Ayman A. Swelum
- Department of Animal Production, College of Food and Agriculture Sciences, King Saud University, Riyadh, 1451, Saudi Arabia
| | - Liliana Aguilar Marcelino
- National Center for Disciplinary Research in Animal Health and Safety (INIFAP), Km 11 Federal Road Cuernavaca-Cuautla, 62550, Jiutepec, Morelos, Mexico
| | - Sadaf Niaz
- Department of Zoology, Abdul Wali Khan University Mardan, Mardan, 23200, Pakistan
| | - Adil Khan
- Department of Zoology, Bacha Khan University Charsadda, Charsadda, 24420, Pakistan
- Department of Biology, Mount Allison University, Sackville, E4L 1G7, New Brunswick, Canada
| | - Mourad Ben Said
- Laboratory of Microbiology, National School of Veterinary Medicine of Sidi Thabet, University of Manouba, Manouba, 2010, Tunisia
- Department of Basic Sciences, Higher Institute of Biotechnology of Sidi Thabet, University of Manouba, Manouba, 2010, Tunisia
| | - Chien-Chin Chen
- Department of Biotechnology and Bioindustry Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan
- Department of Pathology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, 600, Taiwan
- Department of Cosmetic Science, Chia Nan University of Pharmacy and Science, Tainan, 717, Taiwan
- Ph.D. Program in Translational Medicine, Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung, 40227, Taiwan
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Panecka-Hofman J, Poehner I. Structure and dynamics of pteridine reductase 1: the key phenomena relevant to enzyme function and drug design. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2023; 52:521-532. [PMID: 37608196 PMCID: PMC10618315 DOI: 10.1007/s00249-023-01677-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 07/08/2023] [Accepted: 07/24/2023] [Indexed: 08/24/2023]
Abstract
Pteridine reductase 1 (PTR1) is a folate and pterin pathway enzyme unique for pathogenic trypanosomatids. As a validated drug target, PTR1 has been the focus of recent research efforts aimed at finding more effective treatments against human parasitic diseases such as leishmaniasis or sleeping sickness. Previous PTR1-centered structural studies highlighted the enzyme characteristics, such as flexible regions around the active site, highly conserved structural waters, and species-specific differences in pocket properties and dynamics, which likely impacts the binding of natural substrates and inhibitors. Furthermore, several aspects of the PTR1 function, such as the substrate inhibition phenomenon and the level of ligand binding cooperativity in the enzyme homotetramer, likely related to the global enzyme dynamics, are poorly known at the molecular level. We postulate that future drug design efforts could greatly benefit from a better understanding of these phenomena through studying both the local and global PTR1 dynamics. This review highlights the key aspects of the PTR1 structure and dynamics relevant to structure-based drug design that could be effectively investigated by modeling approaches. Particular emphasis is given to the perspective of molecular dynamics, what has been accomplished in this area to date, and how modeling could impact the PTR1-targeted drug design in the future.
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Affiliation(s)
- Joanna Panecka-Hofman
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland.
| | - Ina Poehner
- School of Pharmacy, University of Eastern Finland, Yliopistonranta 1 C, 70211, Kuopio, Finland
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Soni M, Pratap JV. Development of Novel Anti-Leishmanials: The Case for Structure-Based Approaches. Pathogens 2022; 11:pathogens11080950. [PMID: 36015070 PMCID: PMC9414883 DOI: 10.3390/pathogens11080950] [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: 05/06/2022] [Revised: 08/16/2022] [Accepted: 08/17/2022] [Indexed: 11/16/2022] Open
Abstract
The neglected tropical disease (NTD) leishmaniasis is the collective name given to a diverse group of illnesses caused by ~20 species belonging to the genus Leishmania, a majority of which are vector borne and associated with complex life cycles that cause immense health, social, and economic burdens locally, but individually are not a major global health priority. Therapeutic approaches against leishmaniasis have various inadequacies including drug resistance and a lack of effective control and eradication of the disease spread. Therefore, the development of a rationale-driven, target based approaches towards novel therapeutics against leishmaniasis is an emergent need. The utilization of Artificial Intelligence/Machine Learning methods, which have made significant advances in drug discovery applications, would benefit the discovery process. In this review, following a summary of the disease epidemiology and available therapies, we consider three important leishmanial metabolic pathways that can be attractive targets for a structure-based drug discovery approach towards the development of novel anti-leishmanials. The folate biosynthesis pathway is critical, as Leishmania is auxotrophic for folates that are essential in many metabolic pathways. Leishmania can not synthesize purines de novo, and salvage them from the host, making the purine salvage pathway an attractive target for novel therapeutics. Leishmania also possesses an organelle glycosome, evolutionarily related to peroxisomes of higher eukaryotes, which is essential for the survival of the parasite. Research towards therapeutics is underway against enzymes from the first two pathways, while the third is as yet unexplored.
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Affiliation(s)
- Mohini Soni
- Biochemistry and Structural Biology Division, CSIR-Central Drug Research Institute, Sector-10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - J. Venkatesh Pratap
- Biochemistry and Structural Biology Division, CSIR-Central Drug Research Institute, Sector-10, Jankipuram Extension, Sitapur Road, Lucknow 226031, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
- Correspondence:
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Combined gene deletion of dihydrofolate reductase-thymidylate synthase and pteridine reductase in Leishmania infantum. PLoS Negl Trop Dis 2021; 15:e0009377. [PMID: 33905412 PMCID: PMC8104401 DOI: 10.1371/journal.pntd.0009377] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 05/07/2021] [Accepted: 04/11/2021] [Indexed: 12/13/2022] Open
Abstract
Our understanding of folate metabolism in Leishmania has greatly benefited from studies of resistance to the inhibitor methotrexate (MTX). Folates are reduced in Leishmania by the bifunctional dihydrofolate reductase thymidylate synthase (DHFR-TS) and by pteridine reductase (PTR1). To further our understanding of folate metabolism in Leishmania, a Cos-seq genome-wide gain of function screen was performed against MTX and against the two thymidylate synthase (TS) inhibitors 5-fluorouracil and pemetrexed. The screen revealed DHFR-TS and PTR1 but also the nucleoside transporter NT1 and one hypothetical gene derived from chromosome 31. For MTX, the concentration of folate in the culture medium affected the enrichment pattern for genes retrieved by Cos-seq. We generated a L. infantum DHFR-TS null mutant that was thymidine auxotroph, a phenotype that could be rescued by the addition of thymidine or by transfection of the flavin dependent bacterial TS gene ThyX. In these DHFR-TS null mutants it was impossible to obtain a chromosomal null mutant of PTR1 except if DHFR-TS or PTR1 were provided episomally. The transfection of ThyX however did not allow the elimination of PTR1 in a DHFR-TS null mutant. Leishmania can survive without copies of either DHFR-TS or PTR1 but not without both. Provided that our results observed with the insect stage parasites are also replicated with intracellular parasites, it would suggest that antifolate therapy in Leishmania would only work if both DHFR-TS and PTR1 would be targeted simultaneously. The protozoan parasite Leishmania is auxotroph for folate and unconjugated pterins and salvages both from the mammalian host. Two enzymes of the folate metabolism pathway, namely the bifunctional dihydrofolate reductase-thymidylate synthase (DHFR-TS) and the pteridine reductase 1 (PTR1), are being evaluated for drug discovery and repurposing of existing anti-metabolites. Despite their apparent potential, development of DHFR-TS and PTR1 targeted chemotherapy against Leishmania is still awaiting. Here we revisited folate metabolism at the genomic level and report on the identification of known resistance genes alongside some new ones. Through gene disruption studies we found that L. infantum DHFR-TS null mutants are thymidine auxotroph and that these can be rescued by the bacterial flavin dependent thymidylate synthase ThyX. We also found that PTR1 is essential in the absence of a functional DHFR-TS even in the presence of ThyX or thymidine supplementation, indicating the essential role of reduced pterins or folate beyond thymidine synthesis. This study indicates that simultaneous targeting of DHFR-TS and PTR1 will be required for the development of anti-folate chemotherapy against Leishmania.
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Labine M, DePledge L, Feirer N, Greenwich J, Fuqua C, Allen KD. Enzymatic and Mutational Analysis of the PruA Pteridine Reductase Required for Pterin-Dependent Control of Biofilm Formation in Agrobacterium tumefaciens. J Bacteriol 2020; 202:JB.00098-20. [PMID: 32482721 PMCID: PMC8404713 DOI: 10.1128/jb.00098-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/22/2020] [Indexed: 11/20/2022] Open
Abstract
Pterins are ubiquitous biomolecules with diverse functions including roles as cofactors, pigments, and redox mediators. Recently, a novel pterin-dependent signaling pathway that controls biofilm formation was identified in the plant pathogen, Agrobacterium tumefaciens A key player in this pathway is a pteridine reductase termed PruA, where its enzymatic activity has been shown to control surface attachment and limit biofilm formation. Here, we biochemically characterize PruA to investigate the catalytic properties and substrate specificity of this pteridine reductase. PruA demonstrates maximal catalytic efficiency with dihydrobiopterin and comparable activities with the stereoisomers dihydromonapterin and dihydroneopterin. Since A. tumefaciens does not synthesize or utilize biopterins, the likely physiological substrate is dihydromonapterin or dihydroneopterin, or both. Notably, PruA does not exhibit pteridine reductase activity with dihydrofolate or fully oxidized pterins. Site-directed mutagenesis studies of a conserved tyrosine residue, the key component of a putative catalytic triad, indicate that this tyrosine is not directly involved in PruA catalysis but may be important for substrate or cofactor binding. Additionally, mutagenesis of the arginine residue in the N-terminal TGX3RXG motif significantly reduces the catalytic efficiency of PruA, supporting its proposed role in pterin binding and catalysis. Finally, we report the enzymatic characterization of PruA homologs from Pseudomonas aeruginosa and Brucella abortus, thus expanding the roles and potential significance of pteridine reductases in diverse bacteria.Importance Biofilms are complex multicellular communities that are formed by diverse bacteria. In the plant pathogen, Agrobacterium tumefaciens, the transition from a free-living motile state to a non-motile biofilm state is governed by a novel signaling pathway involving small molecules called pterins. The involvement of pterins in biofilm formation is unexpected and prompts many questions about the molecular details of this pathway. This work biochemically characterizes the PruA pteridine reductase involved in the signaling pathway to reveal its enzymatic properties and substrate preference, thus providing important insight into pterin biosynthesis and its role in A. tumefaciens biofilm control. Additionally, the enzymatic characteristics of related pteridine reductases from mammalian pathogens are examined to uncover potential roles of these enzymes in other bacteria.
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Affiliation(s)
- Monica Labine
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Lisa DePledge
- Department of Chemistry and Biochemistry, Gonzaga University, Spokane, WA, USA
| | - Nathan Feirer
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | | | - Clay Fuqua
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Kylie D Allen
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
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Wagner V, Minguez-Menendez A, Pena J, Fernández-Prada C. Innovative Solutions for the Control of Leishmaniases: Nanoscale Drug Delivery Systems. Curr Pharm Des 2019; 25:1582-1592. [DOI: 10.2174/1381612825666190621154552] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 06/15/2019] [Indexed: 12/26/2022]
Abstract
Background:
Leishmania are sandfly-transmitted protozoan parasites that harbour within the macrophages
of a mammalian host and cause leishmaniasis, a serious zoonotic disease that threatens the lives of millions
worldwide. Its numerous forms (cutaneous, mucocutaneous, and visceral) are currently treated with a sparse
arsenal of drugs, specifically antimonials, amphotericin B, miltefosine, and paromomycin, for which drug resistance
and clinical failure are rampant. Medicine is presently trending towards nanotechnology to aid in the successful
delivery of drugs. Vehicles such as lipid-based nanocarriers, polymer-based nanoparticles, and metal ions
and oxides have been previously demonstrated to improve bioavailability of drugs and decrease toxicity for the
patient. These cutting-edge solutions can be combined with existing active molecules, as well as novel drugs or
plant extracts with promising antileishmanial activity.
Conclusion:
This review explores the current evidence for the treatment of leishmaniases using nanoscale drug
delivery systems (specifically lipid-, polymer- and metal-based systems) and encourages further development of
the aforementioned nanotechnologies for treatment of Leishmania.
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Affiliation(s)
- Victoria Wagner
- Departement de Pathologie et Microbiologie, Faculte de Medecine Veterinaire Universite de Montreal, Saint-Hyacinthe, Quebec, Canada
| | - Aida Minguez-Menendez
- Departement de Pathologie et Microbiologie, Faculte de Medecine Veterinaire Universite de Montreal, Saint-Hyacinthe, Quebec, Canada
| | - Joan Pena
- Departement de Pathologie et Microbiologie, Faculte de Medecine Veterinaire Universite de Montreal, Saint-Hyacinthe, Quebec, Canada
| | - Christopher Fernández-Prada
- Departement de Pathologie et Microbiologie, Faculte de Medecine Veterinaire Universite de Montreal, Saint-Hyacinthe, Quebec, Canada
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Vadloori B, Sharath AK, Prabhu NP, Maurya R. Homology modelling, molecular docking, and molecular dynamics simulations reveal the inhibition of Leishmania donovani dihydrofolate reductase-thymidylate synthase enzyme by Withaferin-A. BMC Res Notes 2018; 11:246. [PMID: 29661206 PMCID: PMC5902840 DOI: 10.1186/s13104-018-3354-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 04/11/2018] [Indexed: 01/21/2023] Open
Abstract
Objective Present in silico study was carried out to explore the mode of inhibition of Leishmania donovani dihydrofolate reductase-thymidylate synthase (Ld DHFR-TS) enzyme by Withaferin-A, a withanolide isolated from Withania somnifera. Withaferin-A (WA) is known for its profound multifaceted properties, but its antileishmanial activity is not well understood. The parasite’s DHFR-TS enzyme is diverse from its mammalian host and could be a potential drug target in parasites. Results A 3D model of Ld DHFR-TS enzyme was built and verified using Ramachandran plot and SAVES tools. The protein was docked with WA-the ligand, methotrexate (MTX)-competitive inhibitor of DHFR, and dihydrofolic acid (DHFA)-substrate for DHFR-TS. Molecular docking studies reveal that WA competes for active sites of both Hu DHFR and TS enzymes whereas it binds to a site other than active site in Ld DHFR-TS. Moreover, Lys 173 residue of DHFR-TS forms a H-bond with WA and has higher binding affinity to Ld DHFR-TS than Hu DHFR and Hu TS. The MD simulations confirmed the H-bonding interactions were stable. The binding energies of WA with Ld DHFR-TS were calculated using MM-PBSA. Homology modelling, molecular docking and MD simulations of Ld DHFR-TS revealed that WA could be a potential anti-leishmanial drug. Electronic supplementary material The online version of this article (10.1186/s13104-018-3354-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bharadwaja Vadloori
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao Road, Gachibowli, Hyderabad, 500046, India
| | - A K Sharath
- Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad, India
| | - N Prakash Prabhu
- Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad, India
| | - Radheshyam Maurya
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao Road, Gachibowli, Hyderabad, 500046, India.
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Abstract
AbstractThe protozoan parasiteLeishmaniais endemic in large parts of the world which causes leishmaniasis. Its visceral form is fatal if not treated and is caused mostly byLeishmania donovani,Leishmania infantumandLeishmania chagasi. Given the difficulties linked to vector (sandfly) control and the lack of an effective vaccine, the control of leishmaniasis relies mostly on chemotherapy. Unfortunately, the prevalence of parasites becoming resistant to the first-line drug pentavalent antimony (SbV) is increasing worldwide. Few alternative drugs are available that includes amphotericin B, pentamidine and miltefosine (oral). Already, decreases in efficacy, resistance and toxicity have been noted against these drugs. Dry antileishmanial pipeline further indicates the slow pace of drug discovery in this field where resistance as a major barrier. Full understanding of the genetic and molecular basis of the parasite is lagging. Since leishmaniasis is a neglected disease and occurs predominantly in the developing world largely, therefore, it is unaddressed. The pharma industry argues that development of the new drug is too costly and risky to invest in low return neglected diseases is very high. Research is also needed to identify new and effective drug targets. The lack of drug research and development for neglected diseases will require some new strategies. We have discussed the various cause of slow pace of antileishmanial drug discovery in this review to pay attention of researchers and also take the public and private initiative to make the process fast for new antileishmanial drug development.
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Chandrasekaran S, Veronica J, Gundampati RK, Sundar S, Maurya R. Exploring the inhibitory activity of Withaferin-A against Pteridine reductase-1 of L. donovani. J Enzyme Inhib Med Chem 2015; 31:1029-37. [DOI: 10.3109/14756366.2015.1088841] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
| | - Jalaja Veronica
- Department of Animal Biology, University of Hyderabad, Hyderabad, Andhra Pradesh, India,
| | - Ravi Kumar Gundampati
- Molecular Biology Unit, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India, and
| | - Shyam Sundar
- Infectious Research Laboratory, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Radheshyam Maurya
- Department of Animal Biology, University of Hyderabad, Hyderabad, Andhra Pradesh, India,
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Laffitte MCN, Genois MM, Mukherjee A, Légaré D, Masson JY, Ouellette M. Formation of linear amplicons with inverted duplications in Leishmania requires the MRE11 nuclease. PLoS Genet 2014; 10:e1004805. [PMID: 25474106 PMCID: PMC4256157 DOI: 10.1371/journal.pgen.1004805] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 10/06/2014] [Indexed: 11/22/2022] Open
Abstract
Extrachromosomal DNA amplification is frequent in the protozoan parasite Leishmania selected for drug resistance. The extrachromosomal amplified DNA is either circular or linear, and is formed at the level of direct or inverted homologous repeated sequences that abound in the Leishmania genome. The RAD51 recombinase plays an important role in circular amplicons formation, but the mechanism by which linear amplicons are formed is unknown. We hypothesized that the Leishmania infantum DNA repair protein MRE11 is required for linear amplicons following rearrangements at the level of inverted repeats. The purified LiMRE11 protein showed both DNA binding and exonuclease activities. Inactivation of the LiMRE11 gene led to parasites with enhanced sensitivity to DNA damaging agents. The MRE11−/− parasites had a reduced capacity to form linear amplicons after drug selection, and the reintroduction of an MRE11 allele led to parasites regaining their capacity to generate linear amplicons, but only when MRE11 had an active nuclease activity. These results highlight a novel MRE11-dependent pathway used by Leishmania to amplify portions of its genome to respond to a changing environment. Extrachromosomal DNA amplification is frequent in the human protozoan parasite Leishmania when challenged with drug or other stressful conditions. DNA amplicons, either circular or linear, are formed by recombination between direct or inverted repeats spread throughout the genome of the parasite. The recombinase RAD51 is involved in the formation of circular amplicons, but the mechanism by which linear amplicons are formed is still unknown in this parasite. Studies in other organisms have provided some evidence that a DNA break is required for linear amplifications, and that the DNA repair protein MRE11 can be involved in this process. In this work, we present our biochemical, cellular and molecular characterization of the Leishmania infantum MRE11 orthologue and provide evidence that this nuclease is involved in the formation of linear amplicons in Leishmania. Our results highlight a novel MRE11-dependent pathway used by Leishmania to amplify portions of its genome to respond to a changing environment.
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Affiliation(s)
| | - Marie-Michelle Genois
- Centre de Recherche en Infectiologie du CHU de Québec, Quebec City, Québec, Canada
- Genome Stability Laboratory, CHU de Quebec Research Center, HDQ Pavillon, Oncology Axis, Quebec City, Québec, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Quebec City, Québec, Canada
| | - Angana Mukherjee
- Centre de Recherche en Infectiologie du CHU de Québec, Quebec City, Québec, Canada
| | - Danielle Légaré
- Centre de Recherche en Infectiologie du CHU de Québec, Quebec City, Québec, Canada
| | - Jean-Yves Masson
- Genome Stability Laboratory, CHU de Quebec Research Center, HDQ Pavillon, Oncology Axis, Quebec City, Québec, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Quebec City, Québec, Canada
| | - Marc Ouellette
- Centre de Recherche en Infectiologie du CHU de Québec, Quebec City, Québec, Canada
- * E-mail:
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Proteomic analysis of metacyclogenesis in Leishmania infantum wild-type and PTR1 null mutant. EUPA OPEN PROTEOMICS 2014. [DOI: 10.1016/j.euprot.2014.07.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Singh N, Mishra BB, Bajpai S, Singh RK, Tiwari VK. Natural product based leads to fight against leishmaniasis. Bioorg Med Chem 2013; 22:18-45. [PMID: 24355247 DOI: 10.1016/j.bmc.2013.11.048] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Revised: 11/18/2013] [Accepted: 11/23/2013] [Indexed: 11/16/2022]
Abstract
The growing incidence of parasitic resistance against generic pentavalent antimonials, specifically for visceral disease in Indian subcontinent, is a serious issue in Leishmania control. Notwithstanding the two treatment alternatives, that is amphotericin B and miltefosine are being effectively used but their high cost and therapeutic complications limit their use in endemic areas. In the absence of a vaccine candidate, identification, and characterization of novel drugs and targets is a major requirement of leishmanial research. This review describes current drug regimens, putative drug targets, numerous natural products that have shown promising antileishmanial activity alongwith some key issues and strategies for future research to control leishmaniasis worldwide.
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Affiliation(s)
- Nisha Singh
- Molecular Immunology Laboratory, Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India
| | - Bhuwan B Mishra
- Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India
| | - Surabhi Bajpai
- Molecular Immunology Laboratory, Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India
| | - Rakesh K Singh
- Molecular Immunology Laboratory, Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India.
| | - Vinod K Tiwari
- Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India.
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Singh N, Kumar M, Singh RK. Leishmaniasis: current status of available drugs and new potential drug targets. ASIAN PAC J TROP MED 2012; 5:485-97. [PMID: 22575984 DOI: 10.1016/s1995-7645(12)60084-4] [Citation(s) in RCA: 257] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 03/15/2012] [Accepted: 04/15/2012] [Indexed: 02/06/2023] Open
Abstract
The control of Leishmania infection relies primarily on chemotherapy till date. Resistance to pentavalent antimonials, which have been the recommended drugs to treat cutaneous and visceral leishmaniasis, is now widespread in Indian subcontinents. New drug formulations like amphotericin B, its lipid formulations, and miltefosine have shown great efficacy to treat leishmaniasis but their high cost and therapeutic complications limit their usefulness. In addition, irregular and inappropriate uses of these second line drugs in endemic regions like state of Bihar, India threaten resistance development in the parasite. In context to the limited drug options and unavailability of either preventive or prophylactic candidates, there is a pressing need to develop true antileishmanial drugs to reduce the disease burden of this debilitating endemic disease. Notwithstanding significant progress of leishmanial research during last few decades, identification and characterization of novel drugs and drug targets are far from satisfactory. This review will initially describe current drug regimens and later will provide an overview on few important biochemical and enzymatic machineries that could be utilized as putative drug targets for generation of true antileishmanial drugs.
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Affiliation(s)
- Nisha Singh
- Molecular Immunology Laboratory, Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi, India
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Ong HB, Sienkiewicz N, Wyllie S, Fairlamb AH. Dissecting the metabolic roles of pteridine reductase 1 in Trypanosoma brucei and Leishmania major. J Biol Chem 2011; 286:10429-38. [PMID: 21239486 PMCID: PMC3060496 DOI: 10.1074/jbc.m110.209593] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Leishmania parasites are pteridine auxotrophs that use an NADPH-dependent pteridine reductase 1 (PTR1) and NADH-dependent quinonoid dihydropteridine reductase (QDPR) to salvage and maintain intracellular pools of tetrahydrobiopterin (H4B). However, the African trypanosome lacks a credible candidate QDPR in its genome despite maintaining apparent QDPR activity. Here we provide evidence that the NADH-dependent activity previously reported by others is an assay artifact. Using an HPLC-based enzyme assay, we demonstrate that there is an NADPH-dependent QDPR activity associated with both TbPTR1 and LmPTR1. The kinetic properties of recombinant PTR1s are reported at physiological pH and ionic strength and compared with LmQDPR. Specificity constants (kcat/Km) for LmPTR1 are similar with dihydrobiopterin (H2B) and quinonoid dihydrobiopterin (qH2B) as substrates and about 20-fold lower than LmQDPR with qH2B. In contrast, TbPTR1 shows a 10-fold higher kcat/Km for H2B over qH2B. Analysis of Trypanosoma brucei isolated from infected rats revealed that H4B (430 nm, 98% of total biopterin) was the predominant intracellular pterin, consistent with a dual role in the salvage and regeneration of H4B. Gene knock-out experiments confirmed this: PTR1-nulls could only be obtained from lines overexpressing LmQDPR with H4B as a medium supplement. These cells grew normally with H4B, which spontaneously oxidizes to qH2B, but were unable to survive in the absence of pterin or with either biopterin or H2B in the medium. These findings establish that PTR1 has an essential and dual role in pterin metabolism in African trypanosomes and underline its potential as a drug target.
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Affiliation(s)
- Han B Ong
- Division of Biological Chemistry & Drug Discovery, College of Life Sciences, University of Dundee, Wellcome Trust Biocentre, Dundee DD1 5EH, Scotland, United Kingdom
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15
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Gargouri M, Chaudière J, Manigand C, Maugé C, Bathany K, Schmitter JM, Gallois B. The epimerase activity of anthocyanidin reductase from Vitis vinifera and its regiospecific hydride transfers. Biol Chem 2010; 391:219-227. [PMID: 20030585 DOI: 10.1515/bc.2010.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Anthocyanidin reductase (ANR) from Vitis vinifera catalyzes an NADPH-dependent double reduction of anthocyanidins producing a mixture of (2S,3R)- and (2S,3S)-flavan-3-ols. At pH 7.5 and 30 degrees C, the first hydride transfer to anthocyanidin is irreversible, and no intermediate is released during catalysis. ANR reverse activity was assessed in the presence of excess NADP(+). Analysis of products by reverse phase and chiral phase HPLC demonstrates that ANR acts as a flavan-3-ol C(3)-epimerase under such conditions, but this is only observed with 2R-flavan-3-ols, not with 2S-flavan-3-ols produced by the enzyme in the forward reaction. In the presence of deuterated coenzyme 4S-NADPD, ANR transforms anthocyanidins into dideuterated flavan-3-ols. The regiospecificity of deuterium incorporation into catechin and afzelechin - derived from cyanidin and pelargonidin, respectively - was analyzed by liquid chromatography coupled with electro- spray ionization-tandem mass spectrometry (LC/ESI-MS/MS), and it was found that deuterium was always incorporated at C(2) and C(4). We conclude that C(3)-epimerization should be achieved by tautomerization between the two hydride transfers and that this produces a quinone methide intermediate which serves as C(4) target of the second hydride transfer, thereby avoiding any stereospecific modification of carbon 3. The inversion of C(2) stereochemistry required for 'reverse epimerization' suggests that the 2S configuration induces an irreversible product dissociation.
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Affiliation(s)
- Mahmoud Gargouri
- Chimie et Biologie des Membranes et des Nanoobjets UMR CNRS 5248, Bâtiment B8, Avenue des Facultés, Université Bordeaux 1, F-33405 Talence Cedex, France.,Laboratoire de Physiologie Moléculaire des Plantes, Centre de Biotechnologie de Borj-Cedria, B.P. 901, 2050 Hamman-Lif, Tunisia
| | - Jean Chaudière
- Chimie et Biologie des Membranes et des Nanoobjets UMR CNRS 5248, Bâtiment B8, Avenue des Facultés, Université Bordeaux 1, F-33405 Talence Cedex, France
| | - Claude Manigand
- Chimie et Biologie des Membranes et des Nanoobjets UMR CNRS 5248, Bâtiment B8, Avenue des Facultés, Université Bordeaux 1, F-33405 Talence Cedex, France
| | - Chloé Maugé
- Chimie et Biologie des Membranes et des Nanoobjets UMR CNRS 5248, Bâtiment B8, Avenue des Facultés, Université Bordeaux 1, F-33405 Talence Cedex, France
| | - Katell Bathany
- Chimie et Biologie des Membranes et des Nanoobjets UMR CNRS 5248, Bâtiment B8, Avenue des Facultés, Université Bordeaux 1, F-33405 Talence Cedex, France
| | - Jean-Marie Schmitter
- Chimie et Biologie des Membranes et des Nanoobjets UMR CNRS 5248, Bâtiment B8, Avenue des Facultés, Université Bordeaux 1, F-33405 Talence Cedex, France
| | - Bernard Gallois
- Chimie et Biologie des Membranes et des Nanoobjets UMR CNRS 5248, Bâtiment B8, Avenue des Facultés, Université Bordeaux 1, F-33405 Talence Cedex, France
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16
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Pandey VP, Bisht SS, Mishra M, Kumar A, Siddiqi MI, Verma A, Mittal M, Sane SA, Gupta S, Tripathi RP. Synthesis and molecular docking studies of 1-phenyl-4-glycosyl-dihydropyridines as potent antileishmanial agents. Eur J Med Chem 2010; 45:2381-8. [DOI: 10.1016/j.ejmech.2010.02.018] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Revised: 02/03/2010] [Accepted: 02/04/2010] [Indexed: 11/27/2022]
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17
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Nare B, Garraway LA, Vickers TJ, Beverley SM. PTR1-dependent synthesis of tetrahydrobiopterin contributes to oxidant susceptibility in the trypanosomatid protozoan parasite Leishmania major. Curr Genet 2009; 55:287-99. [PMID: 19396443 PMCID: PMC2759280 DOI: 10.1007/s00294-009-0244-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2009] [Revised: 04/04/2009] [Accepted: 04/07/2009] [Indexed: 10/20/2022]
Abstract
Leishmania must survive oxidative stress, but lack many classical antioxidant enzymes and rely heavily on trypanothione-dependent pathways. We used forward genetic screens to recover loci mediating oxidant resistance via overexpression in Leishmania major, which identified pteridine reductase 1 (PTR1). Comparisons of isogenic lines showed ptr1 (-) null mutants were 18-fold more sensitive to H(2)O(2) than PTR1-overproducing lines, and significant three- to fivefold differences were seen with a broad panel of oxidant-inducing agents. The toxicities of simple nitric oxide generators and other drug classes (except antifolates) were unaffected by PTR1 levels. H(2)O(2) susceptibility could be modulated by exogenous biopterin but not folate, in a PTR1- but not dihydrofolate reductase-dependent manner, implicating H(4)B metabolism specifically. Neither H(2)O(2) consumption nor the level of intracellular oxidative stress was affected by PTR1 levels. Coupled with the fact that reduced pteridines are at least 100-fold less abundant than cellular thiols, these data argue strongly that reduced pteridines act through a mechanism other than scavenging. The ability of unconjugated pteridines to counter oxidative stress has implications to infectivity and response to chemotherapy. Since the intracellular pteridine levels of Leishmania can be readily manipulated, these organisms offer a powerful setting for the dissection of pteridine-dependent oxidant susceptibility in higher eukaryotes.
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Affiliation(s)
- Bakela Nare
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115
| | - Levi A. Garraway
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115
| | - Tim J. Vickers
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis MO 63110
| | - Stephen M. Beverley
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis MO 63110
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115
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18
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Moreira W, Leblanc E, Ouellette M. The role of reduced pterins in resistance to reactive oxygen and nitrogen intermediates in the protozoan parasite Leishmania. Free Radic Biol Med 2009; 46:367-75. [PMID: 19022374 DOI: 10.1016/j.freeradbiomed.2008.10.034] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 10/06/2008] [Accepted: 10/07/2008] [Indexed: 11/18/2022]
Abstract
During its life cycle, the protozoan parasite Leishmania experiences oxidative stress when interacting with macrophages. Reduced pterins are known scavengers of reactive oxygen and nitrogen intermediates. Leishmania has a pteridine reductase, PTR1, whose main function is to provide reduced pterins. We investigated the role of PTR1 in resistance to oxidative and nitrosative stress in Leishmania tarentolae, Leishmania infantum, and Leishmania major PTR1(-/-) mutants. The PTR1(-/-) cells of the three species were more sensitive to H2O2- and NO-induced stress. Using a fluorescent probe allowing ROI quantification, we demonstrated an increase in intracellular oxidant molecules in the PTR1(-/-) mutants. The disruption of PTR1 increased metacyclogenesis in L. infantum and L. major. We purified metacyclic parasites from PTR1(-/-) mutants and control cells and tested their intracellular survival in the J774 mouse cell line and in human monocyte-derived macrophages. Our results showed that PTR1(-/-) null mutants survived less in both macrophage models compared to control cells and this decrease was more pronounced in macrophages activated for oxidant production. This study demonstrates that one physiological role of reduced pterins in Leishmania is to deal with oxidative and nitrosative species, and a decreased ability to provide reduced pterins leads to decreased intracellular survival.
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Affiliation(s)
- Wilfried Moreira
- Centre de Recherche en Infectiologie du CHUL, Université Laval, Québec, QC G1V 4G2, Canada
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19
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Kumar P, Kumar A, Verma SS, Dwivedi N, Singh N, Siddiqi MI, Tripathi RP, Dube A, Singh N. Leishmania donovani pteridine reductase 1: biochemical properties and structure-modeling studies. Exp Parasitol 2008; 120:73-9. [PMID: 18617167 DOI: 10.1016/j.exppara.2008.05.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Revised: 05/16/2008] [Accepted: 05/19/2008] [Indexed: 11/21/2022]
Abstract
Pteridine reductase 1 (PTR1, EC 1.5.1.33) is a NADPH dependent short-chain reductase (SDR) responsible for the salvage of pterins in the protozoan parasite Leishmania. This enzyme acts as a metabolic bypass for drugs targeting dihydrofolate reductase, therefore, for successful antifolate chemotherapy to be developed against Leishmania, it must target both enzyme activities. Based on homology model drawn on recombinant pteridine reductase isolated from a clinical isolate of L. donovani, we carried out molecular modeling and docking studies with two compounds of dihydrofolate reductase specificity showing promising antileishmanial activity in vitro. Both the inhibitors appeared to fit well in the active pocket revealing the tight binding of the carboxylic acid ethyl ester group of pyridine moiety to pteridine reductase and identify the important interactions necessary to assist the structure based development of novel pteridine reductase inhibitors.
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Affiliation(s)
- Pranav Kumar
- Drug Target Discovery and Development, Central Drug Research Institute, Chattat Manzil, P.O. Box No. 173, Lucknow 226001, India
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20
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Ubeda JM, Légaré D, Raymond F, Ouameur AA, Boisvert S, Rigault P, Corbeil J, Tremblay MJ, Olivier M, Papadopoulou B, Ouellette M. Modulation of gene expression in drug resistant Leishmania is associated with gene amplification, gene deletion and chromosome aneuploidy. Genome Biol 2008; 9:R115. [PMID: 18638379 PMCID: PMC2530873 DOI: 10.1186/gb-2008-9-7-r115] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Revised: 06/06/2008] [Accepted: 07/18/2008] [Indexed: 12/02/2022] Open
Abstract
Gene expression and DNA copy number analyses using full genome oligonucleotide microarrays of Leishmania reveal molecular mechanisms of methotrexate resistance. Background Drug resistance can be complex, and several mutations responsible for it can co-exist in a resistant cell. Transcriptional profiling is ideally suited for studying complex resistance genotypes and has the potential to lead to novel discoveries. We generated full genome 70-mer oligonucleotide microarrays for all protein coding genes of the human protozoan parasites Leishmania major and Leishmania infantum. These arrays were used to monitor gene expression in methotrexate resistant parasites. Results Leishmania is a eukaryotic organism with minimal control at the level of transcription initiation and few genes were differentially expressed without concomitant changes in DNA copy number. One exception was found in Leishmania major, where the expression of whole chromosomes was down-regulated. The microarrays highlighted several mechanisms by which the copy number of genes involved in resistance was altered; these include gene deletion, formation of extrachromosomal circular or linear amplicons, and the presence of supernumerary chromosomes. In the case of gene deletion or gene amplification, the rearrangements have occurred at the sites of repeated (direct or inverted) sequences. These repeats appear highly conserved in both species to facilitate the amplification of key genes during environmental changes. When direct or inverted repeats are absent in the vicinity of a gene conferring a selective advantage, Leishmania will resort to supernumerary chromosomes to increase the levels of a gene product. Conclusion Aneuploidy has been suggested as an important cause of drug resistance in several organisms and additional studies should reveal the potential importance of this phenomenon in drug resistance in Leishmania.
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Affiliation(s)
- Jean-Michel Ubeda
- Université Laval, Division de Microbiologie, Centre de Recherche en Infectiologie, boulevard Laurier, Québec, G1V 4G2, Canada.
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21
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Wase NV, Wright PC. Systems biology of cyanobacterial secondary metabolite production and its role in drug discovery. Expert Opin Drug Discov 2008; 3:903-29. [DOI: 10.1517/17460441.3.8.903] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Nishikant V Wase
- The University of Sheffield, Biological and Environmental Systems Group, Department of Chemical and Process Engineering, Mappin St., Sheffield, S1 3JD, UK ;
| | - Phillip C Wright
- The University of Sheffield, Biological and Environmental Systems Group, Department of Chemical and Process Engineering, Mappin St., Sheffield, S1 3JD, UK ;
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22
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Papadopoulou B, Kündig C, Singh A, Ouellette M. Drug resistance in Leishmania: similarities and differences to other organisms. Drug Resist Updat 2007; 1:266-78. [PMID: 16904409 DOI: 10.1016/s1368-7646(98)80007-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/1998] [Revised: 06/19/1998] [Accepted: 06/19/1998] [Indexed: 11/28/2022]
Abstract
The main line of defense available against parasitic protozoa is chemotherapy. Drug resistance has emerged however, as a primary obstacle to the successful treatment and control of parasitic diseases. Leishmania spp., the causative agents of leishmaniasis, have served as a useful model for studying mechanisms of drug resistance in vitro. Antimonials and amphotericin B are the first line drugs to treat Leishmania followed by pentamidine and a number of other drugs. Parasites resistant against all these classes of drugs have been selected under laboratory conditions. A multiplicity of resistance mechanisms has been detected, the most prevalent being gene amplification and transport mutations. With the tools now available, it should be possible to elucidate the mechanisms that govern drug resistance in field isolates and develop more effective chemotherapeutic agents.
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Affiliation(s)
- B Papadopoulou
- Centre de Recherche en Infectiologie du Centre de Recherche du CHUL et Départment de Biologie Médicale, Division de Microbiologie, Faculté de Médecine, Université Laval, Québec, Canada GIV 4G2.
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23
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Kumar P, Sundar S, Singh N. Degradation of pteridine reductase 1 (PTR1) enzyme during growth phase in the protozoan parasite Leishmania donovani. Exp Parasitol 2006; 116:182-9. [PMID: 17275814 DOI: 10.1016/j.exppara.2006.12.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2006] [Revised: 12/08/2006] [Accepted: 12/12/2006] [Indexed: 11/26/2022]
Abstract
Pteridine reductase 1 (PTR1) is an essential enzyme of pterin and folate metabolism in the protozoan parasite Leishmania. The present work is focused on the degradation of PTR1 during growth phase in Leishmania donovani. Western blot analysis with PTR1-GFP transfected promastigotes revealed that PTR1 protein was degraded in the stationary phase of growth at the time when the parasites were undergoing metacyclogenesis. Fluorescence microscopy revealed cytoplasmic localization of GFP tagged protein extending to the flagellum in these stationary phase promastigotes, implying that degradation of the protein was not by the usual multivesicular tubule lysosome (MVT) pathway. A probable destruction box of nine amino acids Q63ADLSNVAK71 and possible lysine residue K156 was identified in L. donovani PTR1 to be the site for ubiquitin conjugation. This suggests that PTR1 degradation during the stationary phase of growth is mediated by the proteasome. This leads to lower levels of H4-biopterin, which favors metacyclogenesis, and subsequently results in a highly infective stage of the parasite. Therefore, this finding has importance to identify new target molecule like the proteasome for therapeutic intervention.
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Affiliation(s)
- Pranav Kumar
- Drug Target Discovery and Development Division, Central Drug Research Institute, Lucknow, India
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24
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Kumar P, Kothari H, Singh N. Overexpression in Escherichia coli and purification of pteridine reductase (PTR1) from a clinical isolate of Leishmania donovani. Protein Expr Purif 2005; 38:228-36. [PMID: 15555938 DOI: 10.1016/j.pep.2004.08.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2004] [Revised: 08/03/2004] [Indexed: 10/26/2022]
Abstract
Pteridine reductase 1 (PTR1) is part of a novel metabolic pathway in Leishmania associated with folate metabolism. Its main function is to salvage pterins but a second one is to reduce folates. The novelty and possible uniqueness of the pathway in which PTR1 is involved opens the possibility of developing specific inhibitors, which in combination with dihydrofolate reductase inhibitors could be highly effective against Leishmania. In order to increase our understanding of this putative important chemotherapeutic target, we present here the cloning, overexpression and purification of this enzyme from a clinical isolate of Leishmania donovani causing kala azar in India. This recombinant enzyme will set the basis for inhibition studies as well as for structure-function relationships.
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Affiliation(s)
- Pranav Kumar
- Drug Target Discovery and Development Division, Central Drug Research Institute, Lucknow, India
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25
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Drummelsmith J, Girard I, Trudel N, Ouellette M. Differential protein expression analysis of Leishmania major reveals novel roles for methionine adenosyltransferase and S-adenosylmethionine in methotrexate resistance. J Biol Chem 2004; 279:33273-80. [PMID: 15190060 DOI: 10.1074/jbc.m405183200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leishmania is a trypanosomatid parasite causing serious disease and displaying resistance to various drugs. Here, we present comparative proteomic analyses of Leishmania major parasites that have been either shocked with or selected in vitro for high level resistance to the model antifolate drug methotrexate. Numerous differentially expressed proteins were identified by these experiments. Some were associated with the stress response, whereas others were found to be overexpressed due to genetic linkage to primary resistance mediators present on DNA amplicons. Several proteins not previously associated with resistance were also identified. The role of one of these, methionine adenosyltransferase, was confirmed by gene transfection and metabolite analysis. After a single exposure to low levels of methotrexate, L. major methionine adenosyltransferase transfectants could grow at high concentrations of the drug. Methotrexate resistance was also correlated to increased cellular S-adenosylmethionine levels. The folate and S-adenosylmethionine regeneration pathways are intimately connected, which may provide a basis for this novel resistance phenotype. This thorough comparative proteomic analysis highlights the variety of responses required for drug resistance to be achieved.
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Affiliation(s)
- Jolyne Drummelsmith
- Infectious Diseases Research Centre, Laval University, Quebec City, Quebec G1V 4G2, Canada
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26
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Guimond C, Trudel N, Brochu C, Marquis N, El Fadili A, Peytavi R, Briand G, Richard D, Messier N, Papadopoulou B, Corbeil J, Bergeron MG, Légaré D, Ouellette M. Modulation of gene expression in Leishmania drug resistant mutants as determined by targeted DNA microarrays. Nucleic Acids Res 2004; 31:5886-96. [PMID: 14530437 PMCID: PMC219483 DOI: 10.1093/nar/gkg806] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In the protozoan parasite Leishmania, drug resistance can be a complex phenomenon. Several metabolic pathways and membrane transporters are implicated in the resistance phenotype. To monitor the expression of these genes, we generated custom DNA microarrays with PCR fragments corresponding to 44 genes involved with drug resistance. Transcript profiling of arsenite and antimony resistant mutants with these arrays pinpointed a number of genes overexpressed in mutants, including the ABC transporter PGPA, the glutathione biosynthesis genes gamma-glutamylcysteine synthetase (GSH1) and the glutathione synthetase (GSH2). Competitive hybridisations with total RNA derived from sensitive and methotrexate resistant cells revealed the overexpression of genes coding for dihydrofolate reductase (DHFR-TS), pteridine reductase (PTR1) and S-adenosylmethionine synthase (MAT2) and a down regulation of one gene of the folate transporter (FT) family. By labelling the DNA of sensitive and resistant parasites we could also detect several gene amplification events using DNA microarrays including the amplification of the S-adenosyl homocysteine hydrolase gene (SAHH). Alteration in gene expression detected by microarrays was validated by northern blot analysis, while Southern blots indicated that most genes overexpressed were also amplified, although other mechanisms were also present. The microarrays were useful in the study of resistant parasites to pinpoint several genes linked to drug resistance.
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Affiliation(s)
- Chantal Guimond
- Centre de Recherche en Infectiologie du Centre de Recherche du CHUL and Division de Microbiologie, Faculté de Médecine, Université Laval, Québec, Canada
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27
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Giladi M, Altman-Price N, Levin I, Levy L, Mevarech M. FolM, a new chromosomally encoded dihydrofolate reductase in Escherichia coli. J Bacteriol 2003; 185:7015-8. [PMID: 14617668 PMCID: PMC262705 DOI: 10.1128/jb.185.23.7015-7018.2003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2003] [Accepted: 09/02/2003] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli (thyA DeltafolA) mutants are viable and can grow in minimal medium when supplemented with thymidine alone. Here we present evidence from in vivo and in vitro studies that the ydgB gene determines an alternative dihydrofolate reductase that is related to the trypanosomatid pteridine reductases. We propose to rename this gene folM.
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Affiliation(s)
- Moshe Giladi
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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28
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El-Fadili A, Richard D, Kündig C, Ouellette M. Effect of polyglutamylation of methotrexate on its accumulation and the development of resistance in the protozoan parasite Leishmania. Biochem Pharmacol 2003; 66:999-1008. [PMID: 12963486 DOI: 10.1016/s0006-2952(03)00417-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Folates are polyglutamylated in most organisms, and in cancer cells the polyglutamylation of folates and of the antifolate methotrexate (MTX) is an important determinant of MTX susceptibility. The folylpolyglutamate synthetase (FPGS) responsible for polyglutamylation of folates was recently characterized in the parasite Leishmania. We show here that MTX is polyglutamylated in Leishmania tarentolae and that triglutamates are the predominant form. The glutamate chain length of MTX increases significantly in Leishmania cells transfected with the FPGS gene and decreases in cells with one FPGS allele disrupted. Modulation in the expression of the FPGS gene also has a profound effect on MTX susceptibility and this effect was found to be dependent on the folate concentration of the medium. In the folate-rich medium SDM-79, overexpression of FPGS will confer MTX resistance while in M-199 medium, which has much less folates, FPGS transfectants are more sensitive to MTX. Cells with one allele of FPGS disrupted are more resistant to MTX in low folate medium. The modulation of FPGS expression affects both the short-term and long-term accumulation of folate and MTX, showing a marked decrease in accumulation in the FPGS haploid mutant. This differential accumulation was mediated by decreased influx of the drug into the cell. Finally, the analysis of MTX-resistant Leishmania mutants indicated that the presence of shorter glutamate chains on MTX is correlated with MTX resistance.
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Affiliation(s)
- Amal El-Fadili
- Centre de Recherche en Infectiologie du Centre de Recherche du CHUL and Division de Microbiologie, Faculté de Médecine, Université Laval, Ste-Foy, Québec, Canada G1V 4G2
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29
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Schormann N, Senkovich O, Ananthan S, Chattopadhyay D. Docking and biological activity of pteridine analogs: search for inhibitors of pteridine reductase enzymes from Trypanosoma cruzi. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s0166-1280(03)00403-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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30
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Drummelsmith J, Brochu V, Girard I, Messier N, Ouellette M. Proteome mapping of the protozoan parasite Leishmania and application to the study of drug targets and resistance mechanisms. Mol Cell Proteomics 2003; 2:146-55. [PMID: 12644573 DOI: 10.1074/mcp.m200085-mcp200] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leishmania is a protozoan parasite responsible for significant morbidity and mortality worldwide. Few parasites have been subjected to proteomic analysis to date, but a genome sequencing project for Leishmania major is currently underway, making these studies possible. Here we present a high resolution proteome for L. major comprising almost 3700 spots, making it the most complete two-dimensional gel representation of a parasite proteome generated to date. We have identified a number of landmark proteins by mass spectrometry and show that several of these are valid for the related species Leishmania donovani infantum. We have also observed several forms and fragments of alpha- and beta-tubulins and show that the number and amount of these fragments increase with the age of the parasite culture. Trypanothione reductase (TRYR), which replaces glutathione reductase in trypanosomatid parasites, is an essential protein specific to these parasites and as such is under considerable scrutiny as a drug target. Two-dimensional gel analysis of a L. major strain overexpressing TRYR revealed increased amounts of five spots, all at the predicted molecular weight for TRYR and differing by 0.08 pH units in pI. Mass spectrometry identified four of these as TRYR, leading to the novel suggestion that it could be post-translationally modified. Finally quantitative comparative analysis of a methotrexate-resistant mutant of L. major generated in vitro found that a known primary resistance mediator, the pteridine reductase PTR1, was overexpressed. This constitutes the first proteomic analysis of drug resistance in a parasite and also the clearest identification of a primary drug resistance mechanism using this approach. Together these results provide a framework for further proteomic studies of Leishmania species and demonstrate that these tools are valuable for the essential study of potential drug targets and drug resistance mechanisms.
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Affiliation(s)
- Jolyne Drummelsmith
- Infectious Diseases Research Centre, Laval University, Quebec City, Quebec G1V4G2, Canada
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Richard D, Kündig C, Ouellette M. A new type of high affinity folic acid transporter in the protozoan parasite Leishmania and deletion of its gene in methotrexate-resistant cells. J Biol Chem 2002; 277:29460-7. [PMID: 12023977 DOI: 10.1074/jbc.m204796200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The protozoan parasite Leishmania is a folate auxotroph and thus depends on the uptake of folate from the environment to meet its folate requirement. We show here that Leishmania contains several putative pteridine transporter genes. Some of these genes are deleted in methotrexate-resistant Leishmania cells where there is no measurable uptake of methotrexate. Transport studies suggest that Leishmania has more than one active folate transporter, and one of these, named FT5, corresponds to a very high affinity folate transporter (K(m) 84 nm). The uptake of both folate and methotrexate was impaired in an FT5 null mutant at low substrate concentrations (50 nm), although transport properties at higher concentrations (1000 nm) were not statistically different between wild-type and the FT5 null mutant. Modulation of the expression of FT5 also changes the susceptibility of Leishmania cells to methotrexate. These results have permitted the characterization of a novel class of folate transporters and suggest that the parasite Leishmania has several gene products possibly transporting folates and related molecules under varying conditions.
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Affiliation(s)
- Dave Richard
- Centre de Recherche en Infectiologie du Centre de Recherche du CHUL and Division de Microbiologie, Faculté de Médecine, Université Laval, Québec G1V 4G2, Canada
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Gilbert IH. Inhibitors of dihydrofolate reductase in Leishmania and trypanosomes. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1587:249-57. [PMID: 12084467 DOI: 10.1016/s0925-4439(02)00088-1] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The protozoan diseases leishmaniasis, Chagas' disease and African trypanosomiasis are major health problems in many countries, particularly developing countries, and there are few drugs available to treat these diseases. Dihydrofolate reductase (DHFR) inhibitors have been used successfully in the treatment of a number of other diseases such as cancer, malaria and bacterial infections; however they have not been used for the treatment of these diseases. This article summarises studies on leishmanial and trypanosomal DHFR inhibitor development and evaluation. Possible mechanisms of resistance to DHFR inhibitors are also discussed.
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Affiliation(s)
- Ian H Gilbert
- Welsh School of Pharmacy, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff, UK.
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Ouellette M, Drummelsmith J, El-Fadili A, Kündig C, Richard D, Roy G. Pterin transport and metabolism in Leishmania and related trypanosomatid parasites. Int J Parasitol 2002; 32:385-98. [PMID: 11849635 DOI: 10.1016/s0020-7519(01)00346-0] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The folate metabolic pathway has been exploited successfully for the development of antimicrobial and antineoplasic agents. Inhibitors of this pathway, however, are not useful against Leishmania and other trypanosomatids. Work on the mechanism of methotrexate resistance in Leishmania has dramatically increased our understanding of folate and pterin metabolism in this organism. The metabolic and cellular functions of the reduced form of folates and pterins are beginning to be established and this work has led to several unexpected findings. Moreover, the currently ongoing sequencing efforts on trypanosomatid genomes are suggesting the presence of several gene products that are likely to require folates and pterins. A number of the properties of folate and pterin metabolism are unique suggesting that these pathways are valid and worthwhile targets for drug development.
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Affiliation(s)
- Marc Ouellette
- Centre de recherche en Infectiologie du CHUL, 2705, boul. Laurier, QC, Sainte-Foy, Canada GIV 4G2.
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Cunningham ML, Beverley SM. Pteridine salvage throughout the Leishmania infectious cycle: implications for antifolate chemotherapy. Mol Biochem Parasitol 2001; 113:199-213. [PMID: 11295174 DOI: 10.1016/s0166-6851(01)00213-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Protozoan parasites of the trypanosomatid genus Leishmania are pteridine auxotrophs, and have evolved an elaborate and versatile pteridine salvage network capable of accumulating and reducing pteridines. This includes biopterin and folate transporters (BT1 and FT1), pteridine reductase (PTR1), and dihydrofolate reductase-thymidylate synthase (DHFR-TS). Notably, PTR1 is a novel alternative pteridine reductase whose activity is resistant to inhibition by standard antifolates. In cultured promastigote parasites, PTR1 can function as a metabolic by-pass under conditions of DHFR inhibition and thus reduce the efficacy of chemotherapy. To test whether pteridine salvage occurred in the infectious stage of the parasite, we examined several pathogenic species of Leishmania and the disease-causing amastigote stage that resides within human macrophages. To accomplish this we developed a new sensitive HPLC-based assay for PTR1 activity. These studies established the existence of the pteridine salvage pathway throughout the infectious cycle of Leishmania, including amastigotes. In general, activities were not well correlated with RNA transcript levels, suggesting the occurrence of at least two different modes of post-transcriptional regulation. Thus, pteridine salvage by amastigotes may account for the clinical inefficacy of antifolates against leishmaniasis, and ultimately provide insights into how this may be overcome in the future.
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Affiliation(s)
- M L Cunningham
- Department of Molecular Microbiology, Washington University School of Medicine, St Louis, MO 63110, USA
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Roy G, Kündig C, Olivier M, Papadopoulou B, Ouellette M. Adaptation of Leishmania cells to in vitro culture results in a more efficient reduction and transport of biopterin. Exp Parasitol 2001; 97:161-8. [PMID: 11312578 DOI: 10.1006/expr.2001.4595] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Leishmania major and Leishmania donovani cells freshly isolated from infected animals divided slowly as axenic promastigotes but the addition of biopterin in the culture medium greatly enhanced their growth. However, when cells were subjected to serial passages and adapted to culture, this growth-promoting effect of biopterin was no longer observed. Genetic analysis of these culture-adapted Leishmania cells demonstrated that the genes coding for the pterin reductase PTR1 or for the biopterin transporter BT1 were over-expressed. This suggests that Leishmania cells adapted to culture were more efficient in utilizing biopterin, an essential growth factor in Leishmania.
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Affiliation(s)
- G Roy
- Centre de Recherche en Infectiologie du Centre de Recherche du CHUL, Université Laval, Québec, Canada
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Ouellette M, Leblanc E, Kündig C, Papadopoulou B. Antifolate resistance mechanisms from bacteria to cancer cells with emphasis on parasites. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1999; 456:99-113. [PMID: 10549365 DOI: 10.1007/978-1-4615-4897-3_6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- M Ouellette
- Département de Microbiologie, Université Laval, Québec, Canada
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Kündig C, Leblanc E, Papadopoulou B, Ouellette M. Role of the locus and of the resistance gene on gene amplification frequency in methotrexate resistant Leishmania tarentolae. Nucleic Acids Res 1999; 27:3653-9. [PMID: 10471733 PMCID: PMC148619 DOI: 10.1093/nar/27.18.3653] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The protozoan parasite Leishmania resists the antifolate methotrexate (MTX) by amplifying the R locus dihydrofolate reductase-thymidylate synthase ( dhfr-ts ) gene, the H locus ptr1 pterin reductase gene, and finally by mutation in a common folate/MTX transporter. Amplification of dhfr-ts has never been observed in Leishmania tarentolae MTX resistant mutants while ptr1 amplification is common. We have selected a L.tarentolae ptr1 null mutant for MTX resistance and observed dhfr-ts amplification in this mutant demonstrating that once a preferred resistance mechanism is unavailable, a second one will take over. By introducing the ptr1 gene at the R locus and the dhfr-ts gene at the H locus by gene targeting, we investigated the role of the resistance gene and the locus on the rate of gene amplification. Transfection studies indicated that ptr1 gave higher levels of MTX resistance than dhfr-ts. Consistent with this, when ptr1 was present as part of either the H locus or the R locus it was invariably amplified, while dhfr-ts was only amplified when ptr1 was inactivated. When dhfr-ts was present in a ptr1 null background on both the H locus and the R locus, amplification from the H locus was more frequent suggesting that both the gene and the locus are determining the frequency of gene amplification in Leishmania.
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Affiliation(s)
- C Kündig
- Centre de Recherche en Infectiologie du CHUL and Département de Biologie Médicale, Division de Microbiologie, Faculté de Médecine, Université Laval, Québec, Canada
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Chang CF, Bray T, Whiteley JM. Mutant PTR1 proteins from Leishmania tarentolae: comparative kinetic properties and active-site labeling. Arch Biochem Biophys 1999; 368:161-71. [PMID: 10415124 DOI: 10.1006/abbi.1999.1290] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PTR1, the gene promoting MTX resistance following gene amplification or DNA transfection in Leishmania tarentolae and selected mutants, has been cloned and heavily overexpressed (>100 mg/liter) in Escherichia coli strain BL21 (DE3). Protein has been purified, essentially to homogeneity, in two steps, via ammonium sulfate precipitation and chromatography on DEAE-Trisacryl. The active proteins are tetramers and display optimal pteridine reductase activity at pH 6.0 using biopterin as substrate and NADPH as the reduced dinucleotide cofactor. 2,4-Diaminopteridine substrate analogues are strong competitive inhibitors (K(i) approximately 38 --> 3 nM) against the pterin substrate and both NADP(+) and folate are inhibitors although somewhat weaker. Dihydropteridines are poor substrates compared to the fully oxidized pteridine. Kinetic analysis affords the usual Michaelis constants and in addition shows that inhibition by NADP(+) allows the formation of ternary nonproductive complexes with folate. The kinetic results are consistent with a sequential ordered bi-bi kinetic mechanism in which first NADPH and then pteridine bind to the free enzyme. Sequence comparisons suggest that PTR1 belongs to the short-chain dehydrogenase/reductase (SDR) family containing an amino-terminal glycine-rich dinucleotide binding site plus a catalytic Y(Xaa)(3)K motif. In accord with this observation, the mutants K16A, Y37D, and R39A and the double mutants K17A:R39A and Y37D:R39A all show a two- to threefold lower binding affinity for NADPH and exhibit low or zero activity. Two Y(Xaa)(3)K regions are present in wild-type PTR1 at 152 and 194. Only Y194F gives protein with zero activity. This observation coupled with affinity labeling of PTR1 by oNADP(+) (2', 3'-dialdehyde derivative of NADP(+)) followed by NaBH(4) reduction, V8 protease digestion, and mass spectral analysis suggests that the motif participating in catalysis is that at 194. The mutation K198Q eliminates inactivation by oNADP(+) supporting the hypothesis that K198 is associated with nucleotide orientation, as has been demonstrated for similar lysine residues in other members of the SDR family.
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Affiliation(s)
- C F Chang
- The Scripps Research Institute, La Jolla, California, 92037, USA
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Chang CF, Bray T, Varughese KI, Whiteley JM. Comparative properties of three pteridine reductases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1999; 463:403-10. [PMID: 10352712 DOI: 10.1007/978-1-4615-4735-8_50] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Affiliation(s)
- C F Chang
- Department of Molecular and Experimental Medicine, Scripps Research Institute, La Jolla, California 92037, USA
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Kündig C, Haimeur A, Légaré D, Papadopoulou B, Ouellette M. Increased transport of pteridines compensates for mutations in the high affinity folate transporter and contributes to methotrexate resistance in the protozoan parasite Leishmania tarentolae. EMBO J 1999; 18:2342-51. [PMID: 10228149 PMCID: PMC1171317 DOI: 10.1093/emboj/18.9.2342] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Functional cloning led to the isolation of a novel methotrexate (MTX) resistance gene in the protozoan parasite Leishmania. The gene corresponds to orfG, an open reading frame (ORF) of the LD1/CD1 genomic locus that is frequently amplified in several Leishmania stocks. A functional ORF G-green fluorescence protein fusion was localized to the plasma membrane. Transport studies indicated that ORF G is a high affinity biopterin transporter. ORF G also transports folic acid, with a lower affinity, but does not transport the drug analog MTX. Disruption of both alleles of orfG led to a mutant strain that became hypersensitive to MTX and had no measurable biopterin transport. Leishmania tarentolae MTX-resistant cells without their high affinity folate transporters have a rearranged orfG gene and increased orfG RNA levels. Overexpression of orfG leads to increased biopterin uptake and, in folate-rich medium, to increased folate uptake. MTX-resistant cells compensate for mutations in their high affinity folate/MTX transporter by overexpressing ORF G, which increases the uptake of pterins and selectively increases the uptake of folic acid, but not MTX.
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Affiliation(s)
- C Kündig
- Centre de Recherche en Infectiologie, CHUQ, Pavilon CHUL, 2705 Boulevard Laurier, RC-709, Ste-Foy, Quebec, Canada G1V 4G2
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Capelluto DG, Hellman U, Cazzulo JJ, Cannata JJ. Purification and partial characterization of three isoforms of serine hydroxymethyltransferase from Crithidia fasciculata. Mol Biochem Parasitol 1999; 98:187-201. [PMID: 10080388 DOI: 10.1016/s0166-6851(98)00166-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Three molecular forms of serine hydroxymethyltransferase (SHMT) have been detected in choanomastigotes of Crithidia fasciculata by DEAE-cellulose chromatography. The three isoforms (named SHMT I, II, and III) presented small differences in charge and molecular weight. Digitonin treatment of intact cells suggested that SHMT III is cytosolic, whereas the other two isoforms are particle bound, one being mitochondrial (SHMT I) and the other one very likely glycosomal (SHMT II). The three SHMT isoforms were purified to homogeneity, and their physicochemical and kinetic properties studied. Determination of their native and subunit molecular masses revealed that all of them have a tetrameric structure. The three isoforms were shown to be PLP-dependent enzymes after L-cysteine and hydroxylamine hydrochloride treatments. They showed similar pH optima, bimodal kinetics for L-serine and Michaelis-Menten kinetics for THF.
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Affiliation(s)
- D G Capelluto
- Centro de Investigaciones Bioenergéticas, Facultad de Medicina-CONICET, Universidad de Buenos Aires, Argentina
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Grondin K, Kündig C, Roy G, Ouellette M. Linear amplicons as precursors of amplified circles in methotrexate-resistant Leishmania tarentolae. Nucleic Acids Res 1998; 26:3372-8. [PMID: 9649621 PMCID: PMC147699 DOI: 10.1093/nar/26.14.3372] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Gene amplification is frequently observed in Leishmania cells selected for drug resistance. By gene targeting we have tagged both alleles of the H locus of Leishmania tarentolae with the neomycin and hygromycin phosphotransferase genes ( neo and hyg ). Selection of these recombinant parasites for low level methotrexate resistance led to amplification of the H locus as part of linear amplicons. The availability of tags has permitted us to determine that both alleles can be amplified in the same cell and that chromosomal deletions are frequent. When methotrexate concentration was increased in subsequent selection steps, circles were observed in several mutants. We have introduced a hyg marker into linear amplicons to test whether the circles originated from linear amplicons. After selection with a high methotrexate concentration, circles with the hyg marker were observed, showing that circles can indeed be formed from linear amplicons. The tagging of H locus alleles permits appreciation of the extent of genetic rearrangements leading to amplicon formation in Leishmania cells selected for drug resistance.
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Affiliation(s)
- K Grondin
- Centre de Recherche en Infectiologie du CHUL and Département de Biologie Médicale, Division de Microbiologie, Faculté de Médecine, Université Laval, Québec, Canada
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Grondin K, Kundig C, Roy G, Ouellette M. Linear amplicons as precursors of amplified circles in methotrexate-resistant Leishmania tarentolae. Nucleic Acids Res 1998. [DOI: 10.1093/nar/26.14.3370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Robello C, Navarro P, Castanys S, Gamarro F. A pteridine reductase gene ptr1 contiguous to a P-glycoprotein confers resistance to antifolates in Trypanosoma cruzi. Mol Biochem Parasitol 1997; 90:525-35. [PMID: 9476799 DOI: 10.1016/s0166-6851(97)00207-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We have isolated the pteridine reductase-1 gene (ptr1), from Trypanosoma cruzi (Y strain), located contiguous to the Trypanosoma cruzi P-glycoprotein-2 (tcpgp2). The gene encodes a member of the family of short-chain dehydrogenases, enzymes that are involved in several oxidoreduction reactions. One member of the family, pteridine reductase-1 (PTR1) has been previously described in Leishmania as being involved in antifolate resistance. The ptr1 gene from T. cruzi presents an 828 bp open reading frame, coding for a 276 amino acid protein with a predicted molecular mass of 30 kDa. The deduced amino acid sequence exhibited a remarkable homology with the ptr1 genes of Leishmania major and Leishmania tarentolae. Southern blot analysis using a specific probe indicated that T. cruzi PTR1 is encoded by a single copy gene located in two chromosomes of about 0.9 and 1.2 Mb. Western blot analysis using a polyclonal antiserum against recombinant PTR1 revealed that the protein is only expressed in the epimastigote forms of the parasite; we did not detect the protein either in the amastigote or trypomastigote forms. Purified recombinant PTR1 exhibits a NADPH-dependent pteridine reductase activity comparable with those described in Leishmania. Gene transfection experiments using the pTEX expression vector show that, under the conditions tested, T. cruzi PTR1 is involved in resistance to the methotrexate, aminopterin and trimethoprim antifolates.
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Affiliation(s)
- C Robello
- Departamento de Bioquímica y Farmacología Molecular, Instituto de Parasitología y Biomedicina López-Neyra Consejo Superior de Investigaciones Científicas, Granada, Spain
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