1
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Hauser DA, Kaiser M, Mäser P, Albisetti A. Venturicidin A affects the mitochondrial membrane potential and induces kDNA loss in Trypanosoma brucei. Antimicrob Agents Chemother 2024; 68:e0167123. [PMID: 38869301 PMCID: PMC11232411 DOI: 10.1128/aac.01671-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 05/19/2024] [Indexed: 06/14/2024] Open
Abstract
Neglected tropical diseases caused by trypanosomatid parasites have devastating health and economic consequences, especially in tropical areas. New drugs or new combination therapies to fight these parasites are urgently needed. Venturicidin A, a macrolide extracted from Streptomyces, inhibits the ATP synthase complex of fungi and bacteria. However, its effect on trypanosomatids is not fully understood. In this study, we tested venturicidin A on a panel of trypanosomatid parasites using Alamar Blue assays and found it to be highly active against Trypanosoma brucei and Leishmania donovani, but much less so against Trypanosoma evansi. Using fluorescence microscopy, we observed a rapid loss of the mitochondrial membrane potential in T. brucei bloodstream forms upon venturicidin A treatment. Additionally, we report the loss of mitochondrial DNA in approximately 40%-50% of the treated parasites. We conclude that venturicidin A targets the ATP synthase of T. brucei, and we suggest that this macrolide could be a candidate for anti-trypanosomatid drug repurposing, drug combinations, or medicinal chemistry programs.
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Affiliation(s)
- Dennis A Hauser
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Marcel Kaiser
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Anna Albisetti
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
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2
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Ramirez-Montoya MV, García-Olivares D, Acosta H, Rojas A. In silico integrative analysis for the characterization of LYT1 a unique protein of Trypanosoma cruzi. J Biomol Struct Dyn 2022; 40:13154-13160. [PMID: 34583627 DOI: 10.1080/07391102.2021.1982771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Trypanosoma rangeli is the most similar organism to Trypanosoma cruzi. They share distribution areas, hosts, and some vectors. However, there are key differences between them; the first lacks a multiplicative form in the host and does not cause disease, while the second is the etiological agent of the American tripanosomiasis, a tropical disease that still does not have an effective vaccine nor treatment. Aiming to reveal the differences in their gene expression patterns in each life cycle form, the comparison of expression profiles was made parting from the ESTs available in TriTrypDB. We verified that there are no genes unique to T. rangeli in the ESTs. Astonishingly, we determined that T. cruzi has a single copy gene called LYT1, which has no similarity to any other protein of any organism on Earth. LYT1 is involved in invasion, motility, and cell cycle, making it an attractive vaccine target. After its identification, using immunoinformatics programs, we found multiple potential B- and T-cell epitopes in this protein, which is also rich in intrinsically disordered regions. Additionally, an approximation of the 3 D structure was predicted where the B-cell epitopes were located to assess their solvent access. We propose that its particular structural conformation confers the flexibility required for the interactions with multiple proteins, which in part may be performed through N-myristoylation sites. Given its important role in the infectiveness of T. cruzi and its antigenic potential, we highlight the need for future studies focused on its molecular and immunological in vivo characterization.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- María Virginia Ramirez-Montoya
- The National Center of Scientific Calculus at the Universidad de Los Andes (CeCalCULA, Universidad de Los Andes, Mérida, Venezuela
| | - Danielle García-Olivares
- The National Center of Scientific Calculus at the Universidad de Los Andes (CeCalCULA, Universidad de Los Andes, Mérida, Venezuela
| | - Héctor Acosta
- Laboratory of Animal Physiology, Faculty of Science, Universidad de Los Andes, Mérida, Venezuela.,Laboratory of Parasite Enzimology, Faculty of Science, Universidad de Los Andes, Mérida, Venezuela
| | - Ascanio Rojas
- The National Center of Scientific Calculus at the Universidad de Los Andes (CeCalCULA, Universidad de Los Andes, Mérida, Venezuela
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3
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Structure-based design, synthesis and evaluation of a novel family of PEX5-PEX14 interaction inhibitors against Trypanosoma. Eur J Med Chem 2022; 243:114778. [DOI: 10.1016/j.ejmech.2022.114778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 09/12/2022] [Accepted: 09/13/2022] [Indexed: 11/22/2022]
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4
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Deng Q, Li H, Feng Y, Xu R, Li W, Zhu R, Akhter D, Shen X, Hu J, Jiang H, Pan R. Defining upstream enhancing and inhibiting sequence patterns for plant peroxisome targeting signal type 1 using large-scale in silico and in vivo analyses. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 111:567-582. [PMID: 35603488 PMCID: PMC9542071 DOI: 10.1111/tpj.15840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/01/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
Peroxisomes are universal eukaryotic organelles essential to plants and animals. Most peroxisomal matrix proteins carry peroxisome targeting signal type 1 (PTS1), a C-terminal tripeptide. Studies from various kingdoms have revealed influences from sequence upstream of the tripeptide on peroxisome targeting, supporting the view that positive charges in the upstream region are the major enhancing elements. However, a systematic approach to better define the upstream elements influencing PTS1 targeting capability is needed. Here, we used protein sequences from 177 plant genomes to perform large-scale and in-depth analysis of the PTS1 domain, which includes the PTS1 tripeptide and upstream sequence elements. We identified and verified 12 low-frequency PTS1 tripeptides and revealed upstream enhancing and inhibiting sequence patterns for peroxisome targeting, which were subsequently validated in vivo. Follow-up analysis revealed that nonpolar and acidic residues have relatively strong enhancing and inhibiting effects, respectively, on peroxisome targeting. However, in contrast to the previous understanding, positive charges alone do not show the anticipated enhancing effect and that both the position and property of the residues within these patterns are important for peroxisome targeting. We further demonstrated that the three residues immediately upstream of the tripeptide are the core influencers, with a 'basic-nonpolar-basic' pattern serving as a strong and universal enhancing pattern for peroxisome targeting. These findings have significantly advanced our knowledge of the PTS1 domain in plants and likely other eukaryotic species as well. The principles and strategies employed in the present study may also be applied to deciphering auxiliary targeting signals for other organelles.
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Affiliation(s)
- Qianwen Deng
- College of Agriculture and BiotechnologyZhejiang UniversityHangzhou310058China
- ZJU‐Hangzhou Global Scientific and Technological Innovation CenterZhejiang UniversityHangzhou310027China
| | - He Li
- Center for Data ScienceZhejiang UniversityHangzhou310058China
| | - Yanlei Feng
- ZJU‐Hangzhou Global Scientific and Technological Innovation CenterZhejiang UniversityHangzhou310027China
| | - Ruonan Xu
- College of Agriculture and BiotechnologyZhejiang UniversityHangzhou310058China
| | - Weiran Li
- College of Agriculture and BiotechnologyZhejiang UniversityHangzhou310058China
| | - Rui Zhu
- College of Agriculture and BiotechnologyZhejiang UniversityHangzhou310058China
| | - Delara Akhter
- College of Agriculture and BiotechnologyZhejiang UniversityHangzhou310058China
- Department of Genetics and Plant BreedingSylhet Agricultural UniversitySylhet3100Bangladesh
| | - Xingxing Shen
- College of Agriculture and BiotechnologyZhejiang UniversityHangzhou310058China
| | - Jianping Hu
- Department of Energy Plant Research Laboratory and Plant Biology DepartmentMichigan State UniversityEast LansingMichigan48824USA
| | - Hangjin Jiang
- Center for Data ScienceZhejiang UniversityHangzhou310058China
| | - Ronghui Pan
- College of Agriculture and BiotechnologyZhejiang UniversityHangzhou310058China
- ZJU‐Hangzhou Global Scientific and Technological Innovation CenterZhejiang UniversityHangzhou310027China
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5
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De-Simone SG, Bourguignon SC, Gonçalves PS, Lechuga GC, Provance DW. Metabolic Alteration of Trypanosoma cruzi during Differentiation of Epimastigote to Trypomastigote Forms. Pathogens 2022; 11:pathogens11020268. [PMID: 35215210 PMCID: PMC8879499 DOI: 10.3390/pathogens11020268] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 12/10/2022] Open
Abstract
Intracellular parasites such as Trypanosoma cruzi need to acquire valuable carbon sources from the host cell to replicate. Here, we investigated the energetic metabolism of T. cruzi during metacyclogenesis through the determination of enzymatic activities and quantification by HPLC of glycolytic and Krebs cycle short-chain carboxylic acids. Altered concentrations in pyruvate, acetate, succinate, and glycerate were measured during the growth of epimastigote in the complex medium BHI and their differentiation to trypomastigotes in the chemically defined medium, TAU3AAG. These alterations should represent significant differential metabolic modifications utilized by either form to generate energy. This paper is the first work dealing with the intracellular organic acid concentration measurement in T. cruzi parasites. Although it confirms the previous assumption of the importance of carbohydrate metabolism, it yields an essential improvement in T. cruzi metabolism knowledge.
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Affiliation(s)
- Salvatore G. De-Simone
- Center for Technological Development in Health (CDTS), FIOCRUZ, National Institute of Science and Technology for Innovation in Neglected Populations Diseases (INCT-IDPN), Rio de Janeiro 21040-900, RJ, Brazil; (P.S.G.); (G.C.L.); (D.W.P.J.)
- Epidemiology and Molecular Systematic Laboratory, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro 21040-900, RJ, Brazil
- Cellular and Molecular Biology Department, Biology Institute, Federal Fluminense University, Niterói 24020-141, RJ, Brazil;
- Correspondence:
| | - Saulo C. Bourguignon
- Cellular and Molecular Biology Department, Biology Institute, Federal Fluminense University, Niterói 24020-141, RJ, Brazil;
| | - Priscila S. Gonçalves
- Center for Technological Development in Health (CDTS), FIOCRUZ, National Institute of Science and Technology for Innovation in Neglected Populations Diseases (INCT-IDPN), Rio de Janeiro 21040-900, RJ, Brazil; (P.S.G.); (G.C.L.); (D.W.P.J.)
- Cellular and Molecular Biology Department, Biology Institute, Federal Fluminense University, Niterói 24020-141, RJ, Brazil;
| | - Guilherme C. Lechuga
- Center for Technological Development in Health (CDTS), FIOCRUZ, National Institute of Science and Technology for Innovation in Neglected Populations Diseases (INCT-IDPN), Rio de Janeiro 21040-900, RJ, Brazil; (P.S.G.); (G.C.L.); (D.W.P.J.)
- Epidemiology and Molecular Systematic Laboratory, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro 21040-900, RJ, Brazil
| | - David W. Provance
- Center for Technological Development in Health (CDTS), FIOCRUZ, National Institute of Science and Technology for Innovation in Neglected Populations Diseases (INCT-IDPN), Rio de Janeiro 21040-900, RJ, Brazil; (P.S.G.); (G.C.L.); (D.W.P.J.)
- Epidemiology and Molecular Systematic Laboratory, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro 21040-900, RJ, Brazil
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6
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Pex7 selectively imports PTS2 target proteins to peroxisomes and is required for anthracnose disease development in Colletotrichum scovillei. Fungal Genet Biol 2021; 157:103636. [PMID: 34742890 DOI: 10.1016/j.fgb.2021.103636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 11/22/2022]
Abstract
Pex7 is a shuttling receptor that imports matrix proteins with a type 2 peroxisomal targeting signal (PTS2) to peroxisomes. The Pex7-mediated PTS2 protein import contributes to crucial metabolic processes such as the fatty acid β-oxidation and glucose metabolism in a number of fungi, but cellular roles of Pex7 between the import of PTS2 target proteins and metabolic processes have not been fully understood. In this study, we investigated the functional roles of CsPex7, a homolog of the yeast Pex7, by targeted gene deletion in the pepper anthracnose fungus Colletotrichum scovillei. CsPex7 was required for carbon source utilization, scavenging of reactive oxygen species, conidial production, and disease development in C. scovillei. The expression of fluorescently tagged PTS2 signal of hexokinases and 3-ketoacyl-CoA thiolases showed that peroxisomal localization of the hexokinase CsGlk1 PTS2 is dependent on CsPex7, but those of the 3-ketoacyl-CoA thiolases are independent on CsPex7. In addition, GFP-tagged CsPex7 proteins were intensely localized to the peroxisomes on glucose-containing media, indicating a role of CsPex7 in glucose utilization. Collectively, these findings indicate that CsPex7 selectively recognizes specific PTS2 signal for import of PTS2-containing proteins to peroxisomes, thereby mediating peroxisomal targeting efficiency of PTS2-containing proteins in C. scovillei. On pepper fruits, the ΔCspex7 mutant exhibited significantly reduced virulence, in which excessive accumulation of hydrogen peroxide was observed in the pepper cells. We think the reduced virulence results from the abnormality in hydrogen peroxide metabolism of the ΔCspex7 mutant. Our findings provide insight into the cellular roles of CsPex7 in PTS2 protein import system.
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7
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Coutinho JVP, Rosa-Fernandes L, Mule SN, de Oliveira GS, Manchola NC, Santiago VF, Colli W, Wrenger C, Alves MJM, Palmisano G. The thermal proteome stability profile of Trypanosoma cruzi in epimastigote and trypomastigote life stages. J Proteomics 2021; 248:104339. [PMID: 34352427 DOI: 10.1016/j.jprot.2021.104339] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/24/2021] [Accepted: 07/28/2021] [Indexed: 12/18/2022]
Abstract
Trypanosoma cruzi is a flagellate protozoa being the etiological agent of Chagas disease, a neglected tropical disease, which still poses a public health problem worldwide. The intricate molecular changes during T. cruzi-host interaction have been explored using different largescale omics techniques. However, protein stability is largely unknown. Thermal proteome profiling (TPP) methodology has the potential to characterize proteome-wide stability highlighting key proteins during T. cruzi infection and life stage transition from the invertebrate to the mammalian host. In the present work, T. cruzi epimastigotes and trypomastigotes cell lysates were subjected to TPP workflow and analyzed by quantitative large-scale mass spectrometry-based proteomics to fit a melting profile for each protein. A total of 2884 proteins were identified and associated to 1741 melting curves being 1370 in trypomastigotes (TmAVG 53.53 °C) and 1279 in epimastigotes (TmAVG 50.89 °C). A total of 453 proteins were identified with statistically different melting profiles between the two life stages. Proteins associated to pathogenesis and intracellular transport had regulated melting temperatures. Membrane and glycosylated proteins had a higher average Tm in trypomastigotes compared to epimastigotes. This study represents the first large-scale comparison of parasite protein stability between life stages. SIGNIFICANCE: Trypanosoma cruzi, a unicellular flagellate parasite, is the etiological agent of Chagas disease, endemic in South America and affecting more that 7 million people worldwide. There is an intense research to identify novel chemotherapeutic and diagnostic targets of Chagas disease. Proteomic approaches have helped in elucidating the quantitative proteome and PTMs changes of T. cruzi during life cycle transition and upon different biotic and abiotic stimuli. However, a comprehensive knowledge of the protein-protein interaction and protein conformation is still missing. In order to fill this gap, this manuscript elucidates the T. cruzi Y strain proteome-wide thermal stability map in the epimastigote and trypomastigote life stages. Comparison between life stages showed a higher average melting temperature stability for trypomastigotes than epimastigotes indicating a host temperature adaptation. Both presented a selective thermal stability shift for cellular compartments, molecular functions and biological processes based on the T. cruzi life stage. Membrane and glycosylated proteins presented a higher thermal stability in trypomastigotes when compared to the epimastigotes.
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Affiliation(s)
- Joao V P Coutinho
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - Livia Rosa-Fernandes
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - Simon Ngao Mule
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - Gilberto Santos de Oliveira
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | | | - Veronica Feijoli Santiago
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - Walter Colli
- Department of Biochemistry, Institute of Chemistry, University of Sao Paulo, Brazil
| | - Carsten Wrenger
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | | | - Giuseppe Palmisano
- GlycoProteomics Laboratory, Department of Parasitology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil.
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8
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Effect of lysine acetylation on the regulation of Trypanosoma brucei glycosomal aldolase activity. Biochem J 2020; 477:1733-1744. [PMID: 32329788 DOI: 10.1042/bcj20200142] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/21/2020] [Accepted: 04/23/2020] [Indexed: 12/29/2022]
Abstract
Post-translational modifications provide suitable mechanisms for cellular adaptation to environmental changes. Lysine acetylation is one of these modifications and occurs with the addition of an acetyl group to Nε-amino chain of this residue, eliminating its positive charge. Recently, we found distinct acetylation profiles of procyclic and bloodstream forms of Trypanosoma brucei, the agent of African Trypanosomiasis. Interestingly, glycolytic enzymes were more acetylated in the procyclic, which develops in insects and uses oxidative phosphorylation to obtain energy, compared with the bloodstream form, whose main source of energy is glycolysis. Here, we investigated whether acetylation regulates the T. brucei fructose 1,6-bisphosphate aldolase. We found that aldolase activity was reduced in procyclic parasites cultivated in the absence of glucose and partial recovered by in vitro deacetylation. Similarly, acetylation of protein extracts from procyclics cultivated in glucose-rich medium, caused a reduction in the aldolase activity. In addition, aldolase acetylation levels were higher in procyclics cultivated in the absence of glucose compared with those cultivated in the presence of glucose. To further confirm the role of acetylation, lysine residues near the catalytic site were substituted by glutamine in recombinant T. brucei aldolase. These replacements, especially K157, inhibited enzymatic activity, changed the electrostatic surface potential, decrease substrate binding and modify the catalytic pocket structure of the enzyme, as predicted by in silico analysis. Taken together, these data confirm the role of acetylation in regulating the activity of an enzyme from the glycolytic pathway of T. brucei, expanding the factors responsible for regulating important pathways in this parasite.
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9
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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] [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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10
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Lutfullahoğlu-Bal G, Seferoğlu AB, Keskin A, Akdoğan E, Dunn CD. A bacteria-derived tail anchor localizes to peroxisomes in yeast and mammalian cells. Sci Rep 2018; 8:16374. [PMID: 30401812 PMCID: PMC6219538 DOI: 10.1038/s41598-018-34646-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 10/18/2018] [Indexed: 11/18/2022] Open
Abstract
Prokaryotes can provide new genetic information to eukaryotes by horizontal gene transfer (HGT), and such transfers are likely to have been particularly consequential in the era of eukaryogenesis. Since eukaryotes are highly compartmentalized, it is worthwhile to consider the mechanisms by which newly transferred proteins might reach diverse organellar destinations. Toward this goal, we have focused our attention upon the behavior of bacteria-derived tail anchors (TAs) expressed in the eukaryote Saccharomyces cerevisiae. In this study, we report that a predicted membrane-associated domain of the Escherichia coli YgiM protein is specifically trafficked to peroxisomes in budding yeast, can be found at a pre-peroxisomal compartment (PPC) upon disruption of peroxisomal biogenesis, and can functionally replace an endogenous, peroxisome-directed TA. Furthermore, the YgiM(TA) can localize to peroxisomes in mammalian cells. Since the YgiM(TA) plays no endogenous role in peroxisomal function or assembly, this domain is likely to serve as an excellent tool allowing further illumination of the mechanisms by which TAs can travel to peroxisomes. Moreover, our findings emphasize the ease with which bacteria-derived sequences might target to organelles in eukaryotic cells following HGT, and we discuss the importance of flexible recognition of organelle targeting information during and after eukaryogenesis.
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Affiliation(s)
- Güleycan Lutfullahoğlu-Bal
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014, Helsinki, Finland
- Department of Molecular Biology and Genetics, Koç University, 34450, Sarıyer, İstanbul, Turkey
| | - Ayşe Bengisu Seferoğlu
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014, Helsinki, Finland
| | - Abdurrahman Keskin
- Department of Molecular Biology and Genetics, Koç University, 34450, Sarıyer, İstanbul, Turkey
- Department of Biological Sciences, Columbia University, New York, NY, 10027, United States of America
| | - Emel Akdoğan
- Department of Molecular Biology and Genetics, Koç University, 34450, Sarıyer, İstanbul, Turkey
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA, 95616, United States of America
| | - Cory D Dunn
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, 00014, Helsinki, Finland.
- Department of Molecular Biology and Genetics, Koç University, 34450, Sarıyer, İstanbul, Turkey.
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Voyton CM, Morris MT, Ackroyd PC, Morris JC, Christensen KA. FRET Flow Cytometry-Based High Throughput Screening Assay To Identify Disrupters of Glucose Levels in Trypanosoma brucei. ACS Infect Dis 2018; 4:1058-1066. [PMID: 29741365 DOI: 10.1021/acsinfecdis.8b00058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Trypanosoma brucei, which causes human African typanosomiasis (HAT), derives cellular ATP from glucose metabolism while in the mammalian host. Targeting glucose uptake or regulation in the parasite has been proposed as a potential therapeutic strategy. However, few methods have been described to identify and characterize potential inhibitors of glucose uptake and regulation. Here, we report development of a screening assay that identifies small molecule disrupters of glucose levels in the cytosol and glycosomes. Using an endogenously expressed fluorescent protein glucose sensor expressed in cytosol or glycosomes, we monitored intracellular glucose depletion in the different cellular compartments. Two glucose level disrupters were identified, one of which only exhibited inhibition of glycosomal glucose and did not affect cytosolic levels. In addition to inhibiting glucose uptake with relatively high potency (EC50 = 700 nM), the compound also showed modest bloodstream form parasite killing activity. Expanding this assay will allow for identification of candidate compounds that disrupt parasite glucose metabolism.
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Affiliation(s)
- Charles M. Voyton
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84601, United States
| | | | - P. Christine Ackroyd
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84601, United States
| | | | - Kenneth A. Christensen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84601, United States
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12
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Voyton CM, Qiu Y, Morris MT, Ackroyd PC, Suryadi J, Crowe L, Morris JC, Christensen KA. A FRET flow cytometry method for monitoring cytosolic and glycosomal glucose in living kinetoplastid parasites. PLoS Negl Trop Dis 2018; 12:e0006523. [PMID: 29851949 PMCID: PMC5997345 DOI: 10.1371/journal.pntd.0006523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 06/12/2018] [Accepted: 05/11/2018] [Indexed: 11/18/2022] Open
Abstract
The bloodstream lifecycle stage of the kinetoplastid parasite Trypanosoma brucei relies solely on glucose metabolism for ATP production, which occurs in peroxisome-like organelles (glycosomes). Many studies have been conducted on glucose uptake and metabolism, but none thus far have been able to monitor changes in cellular and organellar glucose concentration in live parasites. We have developed a non-destructive technique for monitoring changes in cytosolic and glycosomal glucose levels in T. brucei using a fluorescent protein biosensor (FLII12Pglu-700μδ6) in combination with flow cytometry. T. brucei parasites harboring the biosensor allowed for observation of cytosolic glucose levels. Appending a type 1 peroxisomal targeting sequence caused biosensors to localize to glycosomes, which enabled observation of glycosomal glucose levels. Using this approach, we investigated cytosolic and glycosomal glucose levels in response to changes in external glucose or 2-deoxyglucose concentration. These data show that procyclic form and bloodstream form parasites maintain different glucose concentrations in their cytosol and glycosomes. In procyclic form parasites, the cytosol and glycosomes maintain indistinguishable glucose levels (3.4 ± 0.4mM and 3.4 ± 0.5mM glucose respectively) at a 6.25mM external glucose concentration. In contrast, bloodstream form parasites maintain glycosomal glucose levels that are ~1.8-fold higher than the surrounding cytosol, equating to 1.9 ± 0.6mM in cytosol and 3.5 ± 0.5mM in glycosomes. While the mechanisms of glucose transport operating in the glycosomes of bloodstream form T. brucei remain unresolved, the methods described here will provide a means to begin to dissect the cellular machinery required for subcellular distribution of this critical hexose. African sleeping sickness is caused by Trypanosoma brucei. Tens of millions of people living in endemic areas are at risk for the disease. Within the mammalian bloodstream, T. brucei parasites sustain all their energy needs by metabolizing glucose present in the host’s blood within specialized organelles known as glycosomes. In vitro, bloodstream parasites rapidly die if glucose is removed from their environment. This reliance on glucose for survival has made glucose metabolism in T. brucei an important area of study with the aim to develop targeted therapeutics that disrupt glucose metabolism. However, there have previously been no reported methods to study glucose uptake and distribution dynamics in intact glycosomes in live T. brucei. Here we describe development of approaches for observing changes in glucose concentration in glycosomes in live T. brucei. Results obtained using these methods provide new insights into how T. brucei acquires and transports glucose to sustain cell survival.
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Affiliation(s)
- Charles M. Voyton
- Department of Chemistry, Clemson University, Clemson, South Carolina, United States of America
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, United States of America
| | - Yijian Qiu
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| | - Meredith T. Morris
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| | - P. Christine Ackroyd
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, United States of America
| | - Jimmy Suryadi
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| | - Logan Crowe
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| | - James C. Morris
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| | - Kenneth A. Christensen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah, United States of America
- * E-mail:
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13
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Jardim A, Hardie DB, Boitz J, Borchers CH. Proteomic Profiling of Leishmania donovani Promastigote Subcellular Organelles. J Proteome Res 2018; 17:1194-1215. [PMID: 29332401 DOI: 10.1021/acs.jproteome.7b00817] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To facilitate a greater understanding of the biological processes in the medically important Leishmania donovani parasite, a combination of differential and density-gradient ultracentrifugation techniques were used to achieve a comprehensive subcellular fractionation of the promastigote stage. An in-depth label-free proteomic LC-MS/MS analysis of the density gradients resulted in the identification of ∼50% of the Leishmania proteome (3883 proteins detected), which included ∼645 integral membrane proteins and 1737 uncharacterized proteins. Clustering and subcellular localization of proteins was based on a subset of training Leishmania proteins with known subcellular localizations that had been determined using biochemical, confocal microscopy, or immunoelectron microscopy approaches. This subcellular map will be a valuable resource that will help dissect the cell biology and metabolic processes associated with specific organelles of Leishmania and related kinetoplastids.
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Affiliation(s)
- Armando Jardim
- Institute of Parasitology, Macdonald Campus, McGill University , 21111 Lakeshore Road, Saine-Anne-de-Bellevue, Québec H9X 3V9, Canada
| | - Darryl B Hardie
- University of Victoria -Genome British Columbia Proteomics Centre , #3101-4464 Markham Street, Vancouver Island Technology Park, Victoria, British Columbia V8Z7X8, Canada
| | - Jan Boitz
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University , Portland, Oregon 97239, United States
| | - Christoph H Borchers
- University of Victoria -Genome British Columbia Proteomics Centre , #3101-4464 Markham Street, Vancouver Island Technology Park, Victoria, British Columbia V8Z7X8, Canada.,Department of Biochemistry and Biophysics, University of North Carolina , 120 Mason Farm Road, Campus Box 7260 Third Floor, Genetic Medicine Building, Chapel Hill, North Carolina 27599, United States.,Department of Biochemistry and Microbiology, University of Victoria , Petch Building, Room 270d, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada.,Gerald Bronfman Department of Oncology, Jewish General Hospital, McGill University , 3755 Côte Ste-Catherine Road, Montreal, Quebec H3T 1E2, Canada.,Proteomics Centre, Segal Cancer Centre, Lady Davis Institute, Jewish General Hospital, McGill University , 3755 Côte Ste-Catherine Road, Montreal, Quebec H3T 1E2, Canada
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14
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The hydrophobic region of the Leishmania peroxin 14: requirements for association with a glycosome mimetic membrane. Biochem J 2018; 475:511-529. [DOI: 10.1042/bcj20170746] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 12/17/2017] [Accepted: 12/19/2017] [Indexed: 02/07/2023]
Abstract
Protein import into the Leishmania glycosome requires docking of the cargo-loaded peroxin 5 (PEX5) receptor to the peroxin 14 (PEX14) bound to the glycosome surface. To examine the LdPEX14–membrane interaction, we purified L. donovani promastigote glycosomes and determined the phospholipid and fatty acid composition. These membranes contained predominately phosphatidylethanolamine, phosphatidylcholine, and phosphatidylglycerol (PG) modified primarily with C18 and C22 unsaturated fatty acid. Using large unilamellar vesicles (LUVs) with a lipid composition mimicking the glycosomal membrane in combination with sucrose density centrifugation and fluorescence-activated cell sorting technique, we established that the LdPEX14 membrane-binding activity was dependent on a predicted transmembrane helix found within residues 149–179. Monolayer experiments showed that the incorporation of PG and phospholipids with unsaturated fatty acids, which increase membrane fluidity and favor a liquid expanded phase, facilitated the penetration of LdPEX14 into biological membranes. Moreover, we demonstrated that the binding of LdPEX5 receptor or LdPEX5–PTS1 receptor–cargo complex was contingent on the presence of LdPEX14 at the surface of LUVs.
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15
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Moretti NS, Cestari I, Anupama A, Stuart K, Schenkman S. Comparative Proteomic Analysis of Lysine Acetylation in Trypanosomes. J Proteome Res 2018; 17:374-385. [PMID: 29168382 DOI: 10.1021/acs.jproteome.7b00603] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Protein acetylation is a post-translational modification regulating diverse cellular processes. By using proteomic approaches, we identified N-terminal and ε-lysine acetylated proteins in Trypanosoma cruzi and Trypanosoma brucei, which are protozoan parasites that cause significant human and animal diseases. We detected 288 lysine acetylation sites in 210 proteins of procyclic form, an insect stage of T. brucei, and 380 acetylation sites in 285 proteins in the form of the parasite that replicates in mammalian bloodstream. In T. cruzi insect proliferative form we found 389 ε-lysine-acetylated sites in 235 proteins. Notably, we found distinct acetylation profiles according to the developmental stage and species, with only 44 common proteins between T. brucei stages and 18 in common between the two species. While K-ac proteins from T. cruzi are enriched in enzymes involved in oxidation/reduction balance, required for the parasite survival in the host, in T. brucei, most K-ac proteins are enriched in metabolic processes, essential for its adaptation in its hosts. We also identified in both parasites a quite variable N-terminal acetylation sites. Our results suggest that protein acetylation is involved in differential regulation of multiple cellular processes in Trypanosomes, contributing to our understanding of the essential mechanisms for parasite infection and survival.
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Affiliation(s)
- Nilmar Silvio Moretti
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo , R. Pedro de Toledo 669 L6A, 04039-032 São Paulo, SP, Brazil.,Center for Infectious Disease Research , 307 Westlake Avenue North, Suite 500, Seattle, Washington 98109, United States
| | - Igor Cestari
- Center for Infectious Disease Research , 307 Westlake Avenue North, Suite 500, Seattle, Washington 98109, United States
| | - Atashi Anupama
- Center for Infectious Disease Research , 307 Westlake Avenue North, Suite 500, Seattle, Washington 98109, United States
| | - Ken Stuart
- Center for Infectious Disease Research , 307 Westlake Avenue North, Suite 500, Seattle, Washington 98109, United States
| | - Sergio Schenkman
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo , R. Pedro de Toledo 669 L6A, 04039-032 São Paulo, SP, Brazil
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16
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Wangler MF, Chao YH, Bayat V, Giagtzoglou N, Shinde AB, Putluri N, Coarfa C, Donti T, Graham BH, Faust JE, McNew JA, Moser A, Sardiello M, Baes M, Bellen HJ. Peroxisomal biogenesis is genetically and biochemically linked to carbohydrate metabolism in Drosophila and mouse. PLoS Genet 2017; 13:e1006825. [PMID: 28640802 PMCID: PMC5480855 DOI: 10.1371/journal.pgen.1006825] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 05/16/2017] [Indexed: 01/07/2023] Open
Abstract
Peroxisome biogenesis disorders (PBD) are a group of multi-system human diseases due to mutations in the PEX genes that are responsible for peroxisome assembly and function. These disorders lead to global defects in peroxisomal function and result in severe brain, liver, bone and kidney disease. In order to study their pathogenesis we undertook a systematic genetic and biochemical study of Drosophila pex16 and pex2 mutants. These mutants are short-lived with defects in locomotion and activity. Moreover these mutants exhibit severe morphologic and functional peroxisomal defects. Using metabolomics we uncovered defects in multiple biochemical pathways including defects outside the canonical specialized lipid pathways performed by peroxisomal enzymes. These included unanticipated changes in metabolites in glycolysis, glycogen metabolism, and the pentose phosphate pathway, carbohydrate metabolic pathways that do not utilize known peroxisomal enzymes. In addition, mutant flies are starvation sensitive and are very sensitive to glucose deprivation exhibiting dramatic shortening of lifespan and hyperactivity on low-sugar food. We use bioinformatic transcriptional profiling to examine gene co-regulation between peroxisomal genes and other metabolic pathways and we observe that the expression of peroxisomal and carbohydrate pathway genes in flies and mouse are tightly correlated. Indeed key steps in carbohydrate metabolism were found to be strongly co-regulated with peroxisomal genes in flies and mice. Moreover mice lacking peroxisomes exhibit defective carbohydrate metabolism at the same key steps in carbohydrate breakdown. Our data indicate an unexpected link between these two metabolic processes and suggest metabolism of carbohydrates could be a new therapeutic target for patients with PBD.
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Affiliation(s)
- Michael F. Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
- Texas Children’s Hospital, Houston TX, United States of America
- Program in Developmental Biology, BCM, Houston, TX, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital (TCH), Houston, TX, United States of America
| | - Yu-Hsin Chao
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
| | - Vafa Bayat
- Program in Developmental Biology, BCM, Houston, TX, United States of America
| | - Nikolaos Giagtzoglou
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
| | - Abhijit Babaji Shinde
- KU Leuven, Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, Leuven, Belgium
| | - Nagireddy Putluri
- Department of Molecular and Cellular Biology, BCM, Houston, TX, United States of America
| | - Cristian Coarfa
- Department of Molecular and Cellular Biology, BCM, Houston, TX, United States of America
| | - Taraka Donti
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
| | - Brett H. Graham
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
| | - Joseph E. Faust
- Department of BioSciences, Rice University, Houston TX, United States of America
| | - James A. McNew
- Department of BioSciences, Rice University, Houston TX, United States of America
| | - Ann Moser
- Kennedy Krieger Institute, Baltimore MD, United States of America
| | - Marco Sardiello
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
- Program in Developmental Biology, BCM, Houston, TX, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital (TCH), Houston, TX, United States of America
| | - Myriam Baes
- KU Leuven, Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, Leuven, Belgium
| | - Hugo J. Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, United States of America
- Texas Children’s Hospital, Houston TX, United States of America
- Program in Developmental Biology, BCM, Houston, TX, United States of America
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital (TCH), Houston, TX, United States of America
- Howard Hughes Medical Institute, Houston, TX, United States of America
- Department of Neuroscience, BCM, Houston, TX, United States of America
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17
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Keighobadi M, Tarsi AK, Fakhar M, Emami S. Utility of aptamers for antileishmanial drug targets: A potential hypothesis. Trop Parasitol 2017; 7:49-50. [PMID: 28459016 PMCID: PMC5369275 DOI: 10.4103/tp.tp_55_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Masoud Keighobadi
- Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
| | - Abbas Khonakdar Tarsi
- Department of Biochemistry, Biophysic, and Gentic, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mahdi Fakhar
- Molecular and Cell Biology Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran E-mail:
| | - Saeed Emami
- Department of Medicinal Chemistry and Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
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18
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Abstract
Trypanosomatid parasites, including Trypanosoma and Leishmania, are the causative agents of lethal diseases threatening millions of people around the world. These organisms compartmentalize glycolysis in essential, specialized peroxisomes called glycosomes. Peroxisome proliferation can occur through growth and division of existing organelles and de novo biogenesis from the endoplasmic reticulum. The level that each pathway contributes is debated. Current evidence supports the concerted contribution of both mechanisms in an equilibrium that can vary depending on environmental conditions and metabolic requirements of the cell. Homologs of a number of peroxins, the proteins involved in peroxisome biogenesis and matrix protein import, have been identified in T. brucei. Based on these findings, it is widely accepted that glycosomes proliferate through growth and division of existing organelles; however, to our knowledge, a de novo mechanism of biogenesis has not been directly demonstrated. Here, we review recent findings that provide support for the existence of an endoplasmic reticulum (ER)-derived de novo pathway of glycosome biogenesis in T. brucei. Two studies recently identified PEX13.1, a peroxin involved in matrix protein import, in the ER of procyclic form T. brucei. In other eukaryotes, peroxins including PEX13 have been found in the ER of cells undergoing de novo biogenesis of peroxisomes. In addition, PEX16 and PEX19 have been characterized in T. brucei, both of which are important for de novo biogenesis in other eukaryotes. Because glycosomes are rapidly remodeled via autophagy during life cycle differentiation, de novo biogenesis could provide a method of restoring glycosome populations following turnover. Together, the findings we summarize provide support for the hypothesis that glycosome proliferation occurs through growth and division of pre-existing organelles and de novo biogenesis of new organelles from the ER and that the level each mechanism contributes is influenced by glucose availability.
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Affiliation(s)
- Sarah Bauer
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
| | - Meredith T. Morris
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, United States of America
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19
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Boitz JM, Jardim A, Ullman B. GMP reductase and genetic uncoupling of adenylate and guanylate metabolism in Leishmania donovani parasites. Mol Biochem Parasitol 2016; 208:74-83. [PMID: 27343371 DOI: 10.1016/j.molbiopara.2016.06.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 11/26/2022]
Abstract
Purine acquisition is an essential nutritional process for Leishmania. Although purine salvage into adenylate nucleotides has been investigated in detail, little attention has been focused on the guanylate branch of the purine pathway. To characterize guanylate nucleotide metabolism in Leishmania and create a cell culture model in which the pathways for adenylate and guanylate nucleotide synthesis can be genetically uncoupled for functional studies in intact cells, we created and characterized null mutants of L. donovani that were deficient in either GMP reductase alone (Δgmpr) or in both GMP reductase and its paralog IMP dehydrogenase (Δgmpr/Δimpdh). Whereas wild type parasites were capable of utilizing virtually any purine nucleobase/nucleoside, the Δgmpr and Δgmpr/Δimpdh null lines exhibited highly restricted growth phenotypes. The Δgmpr single mutant could not grow in xanthine, guanine, or their corresponding nucleosides, while no purine on its own could support the growth of Δgmpr/Δimpdh cells. Permissive growth conditions for the Δgmpr/Δimpdh necessitated both xanthine, guanine, or the corresponding nucleosides, and additionally, a second purine that could serve as a source for adenylate nucleotide synthesis. Interestingly, GMPR, like its paralog IMPDH, is compartmentalized to the leishmanial glycosome, a process mediated by its COOH-terminal peroxisomal targeting signal. The restricted growth phenotypes displayed by the L. donovani Δgmpr and Δgmpr/Δimpdh null mutants confirms the importance of GMPR in the purine interconversion processes of this parasite.
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Affiliation(s)
- Jan M Boitz
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Mail Code L224, Portland, OR 97239, USA
| | - Armando Jardim
- Institute of Parasitology and Centre for Host-Parasite Interactions, Macdonald Campus of McGill University, 21 111 Lakeshore Road, Ste-Anne-de-Bellevue, Quebec, H9X3V9, Canada
| | - Buddy Ullman
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Mail Code L224, Portland, OR 97239, USA.
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20
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Machado-Silva A, Cerqueira PG, Grazielle-Silva V, Gadelha FR, Peloso EDF, Teixeira SMR, Machado CR. How Trypanosoma cruzi deals with oxidative stress: Antioxidant defence and DNA repair pathways. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2016; 767:8-22. [DOI: 10.1016/j.mrrev.2015.12.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 12/22/2015] [Accepted: 12/23/2015] [Indexed: 02/06/2023]
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21
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Alves LR, Oliveira C, Goldenberg S. Eukaryotic translation elongation factor-1 alpha is associated with a specific subset of mRNAs in Trypanosoma cruzi. BMC Microbiol 2015; 15:104. [PMID: 25986694 PMCID: PMC4436862 DOI: 10.1186/s12866-015-0436-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 05/05/2015] [Indexed: 11/17/2022] Open
Abstract
Background Regulation of gene expression in trypanosomatids is mainly posttranscriptional. Tight regulation of mRNA stability and access to polysomes allows Trypanosoma cruzi to adapt to different environmental conditions during its life cycle. Posttranscriptional regulation requires association between mRNAs and specific proteins to form mRNP complexes. Proteins that lack a canonical RNA-binding domain, such as eukaryotic elongation factor-1α (EF-1α), may also associate with mRNPs. EF-1α is conserved in many organisms, and it plays roles in many cellular processes other than translation, including RNA transport, the cell cycle, and apoptosis. Results In a previous study, EF-1α was found associated with mRNP-forming mRNAs in polysome-free fractions both in epimastigotes growing under normal conditions and in nutritionally stressed parasites. This finding suggested the possibility that EF-1α has a non-canonical function. Thus, we investigated the dynamics of EF-1α in association with T. cruzi epimastigote mRNAs under normal and stressed nutritional conditions. EF-1α is expressed throughout the parasite life cycle, but it shows a slight decrease in protein levels in the metacyclic trypomastigote form. The protein is cytoplasmically localized with a granular pattern in all forms analyzed. Following puromycin treatment, EF-1α migrated with the heaviest gradient fractions in a sucrose polysome profile, indicating that its association with large protein complexes was independent of the translation machinery. We next characterized the EF-1α-associated mRNAs in unstressed and stressed epimastigotes. We observed that specific subsets of mRNAs were associated with EF-1α-mRNPs in unstressed or stressed epimastigotes. Some mRNAs were identified in both physiological conditions, whereas others were condition-specific. Gene ontology analysis identified enrichment of gene sets involved in single-organism metabolic processes, amino acid metabolic processes, ATP and metal ion binding, glycolysis, glutamine metabolic processes, and cobalt and iron ion binding. Conclusion These results indicate that in T. cruzi, as in other eukaryotes, EF-1α may play a non-canonical cellular role. We observed the enrichment of functionally related transcripts bound to EF-1α in normal growth conditions as well as in nutritionally stressed cell indicating a potential role of EF-1α mRNP in stress response. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0436-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Camila Oliveira
- Instituto Carlos Chagas, Fiocruz - PR, Curitiba, Parana, Brazil
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An Insight into the proteome of Crithidia fasciculata choanomastigotes as a comparative approach to axenic growth, peanut lectin agglutination and differentiation of Leishmania spp. promastigotes. PLoS One 2014; 9:e113837. [PMID: 25503511 PMCID: PMC4263474 DOI: 10.1371/journal.pone.0113837] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 10/31/2014] [Indexed: 01/31/2023] Open
Abstract
The life cycle of the trypanosomatid Crithidia fasciculata is monogenetic, as the unique hosts of these parasites are different species of culicids. The comparison of these non-pathogenic microorganisms evolutionary close to other species of trypanosomatids that develop digenetic life cycles and cause chronic severe sickness to millions of people worldwide is of outstanding interest. A ground-breaking analysis of differential protein abundance in Crithidia fasciculata is reported herein. The comparison of the outcome with previous gene expression profiling studies developed in the related human pathogens of the genus Leishmania has revealed substantial differences between the motile stages of these closely related organisms in abundance of proteins involved in catabolism, redox homeostasis, intracellular signalling, and gene expression regulation. As L. major and L. infantum agglutinate with peanut lectin and non-agglutinating parasites are more infective, the agglutination properties were evaluated in C. fasciculata. The result is that choanomastigotes are able to agglutinate with peanut lectin and a non-agglutinating subpopulation can be also isolated. As a difference with L. infantum, the non-agglutinating subpopulation over-expresses the whole machinery for maintenance of redox homeostasis and the translation factors eIF5a, EF1α and EF2, what suggests a relationship between the lack of agglutination and a differentiation process.
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The krebs cycle enzyme α-ketoglutarate decarboxylase is an essential glycosomal protein in bloodstream African trypanosomes. EUKARYOTIC CELL 2014; 14:206-15. [PMID: 25416237 DOI: 10.1128/ec.00214-14] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
α-Ketoglutarate decarboxylase (α-KDE1) is a Krebs cycle enzyme found in the mitochondrion of the procyclic form (PF) of Trypanosoma brucei. The bloodstream form (BF) of T. brucei lacks a functional Krebs cycle and relies exclusively on glycolysis for ATP production. Despite the lack of a functional Krebs cycle, α-KDE1 was expressed in BF T. brucei and RNA interference knockdown of α-KDE1 mRNA resulted in rapid growth arrest and killing. Cell death was preceded by progressive swelling of the flagellar pocket as a consequence of recruitment of both flagellar and plasma membranes into the pocket. BF T. brucei expressing an epitope-tagged copy of α-KDE1 showed localization to glycosomes and not the mitochondrion. We used a cell line transfected with a reporter construct containing the N-terminal sequence of α-KDE1 fused to green fluorescent protein to examine the requirements for glycosome targeting. We found that the N-terminal 18 amino acids of α-KDE1 contain overlapping mitochondrion- and peroxisome-targeting sequences and are sufficient to direct localization to the glycosome in BF T. brucei. These results suggest that α-KDE1 has a novel moonlighting function outside the mitochondrion in BF T. brucei.
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24
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Bauer S, Conlon M, Morris M. Using fluorescent proteins to monitor glycosome dynamics in the African trypanosome. J Vis Exp 2014:e51647. [PMID: 25177828 DOI: 10.3791/51647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Trypanosoma brucei is a kinetoplastid parasite that causes human African trypanosomiasis (HAT), or sleeping sickness, and a wasting disease, nagana, in cattle. The parasite alternates between the bloodstream of the mammalian host and the tsetse fly vector. The composition of many cellular organelles changes in response to these different extracellular conditions. Glycosomes are highly specialized peroxisomes in which many of the enzymes involved in glycolysis are compartmentalized. Glycosome composition changes in a developmental and environmentally regulated manner. Currently, the most common techniques used to study glycosome dynamics are electron and fluorescence microscopy; techniques that are expensive, time and labor intensive, and not easily adapted to high throughput analyses. To overcome these limitations, a fluorescent-glycosome reporter system in which enhanced yellow fluorescent protein (eYFP) is fused to a peroxisome targeting sequence (PTS2), which directs the fusion protein to glycosomes, has been established. Upon import of the PTS2eYFP fusion protein, glycosomes become fluorescent. Organelle degradation and recycling results in the loss of fluorescence that can be measured by flow cytometry. Large numbers of cells (5,000 cells/sec) can be analyzed in real-time without extensive sample preparation such as fixation and mounting. This method offers a rapid way of detecting changes in organelle composition in response to fluctuating environmental conditions.
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Affiliation(s)
- Sarah Bauer
- Department of Genetics and Biochemistry, Clemson University Eukaryotic Pathogens Innovation Center
| | - Meghan Conlon
- Department of Genetics and Biochemistry, Clemson University Eukaryotic Pathogens Innovation Center
| | - Meredith Morris
- Department of Genetics and Biochemistry, Clemson University Eukaryotic Pathogens Innovation Center;
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Güther MS, Urbaniak MD, Tavendale A, Prescott A, Ferguson MAJ. High-confidence glycosome proteome for procyclic form Trypanosoma brucei by epitope-tag organelle enrichment and SILAC proteomics. J Proteome Res 2014; 13:2796-806. [PMID: 24792668 PMCID: PMC4052807 DOI: 10.1021/pr401209w] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Indexed: 01/23/2023]
Abstract
The glycosome of the pathogenic African trypanosome Trypanosoma brucei is a specialized peroxisome that contains most of the enzymes of glycolysis and several other metabolic and catabolic pathways. The contents and transporters of this membrane-bounded organelle are of considerable interest as potential drug targets. Here we use epitope tagging, magnetic bead enrichment, and SILAC quantitative proteomics to determine a high-confidence glycosome proteome for the procyclic life cycle stage of the parasite using isotope ratios to discriminate glycosomal from mitochondrial and other contaminating proteins. The data confirm the presence of several previously demonstrated and suggested pathways in the organelle and identify previously unanticipated activities, such as protein phosphatases. The implications of the findings are discussed.
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Affiliation(s)
- Maria
Lucia S. Güther
- Division of Biological Chemistry and Drug Discovery and Centre for Advanced Scientific
Technologies, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1
5EH, United Kingdom
| | - Michael D. Urbaniak
- Division of Biological Chemistry and Drug Discovery and Centre for Advanced Scientific
Technologies, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1
5EH, United Kingdom
| | - Amy Tavendale
- Division of Biological Chemistry and Drug Discovery and Centre for Advanced Scientific
Technologies, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1
5EH, United Kingdom
| | - Alan Prescott
- Division of Biological Chemistry and Drug Discovery and Centre for Advanced Scientific
Technologies, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1
5EH, United Kingdom
| | - Michael A. J. Ferguson
- Division of Biological Chemistry and Drug Discovery and Centre for Advanced Scientific
Technologies, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1
5EH, United Kingdom
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Analysis of the Leishmania peroxin 7 interactions with peroxin 5, peroxin 14 and PTS2 ligands. Biochem J 2014; 460:273-82. [DOI: 10.1042/bj20131628] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
LPEX7 (Leishmania peroxin 7) is essential for targeting newly synthesized proteins with a PTS2 (peroxisome-targeting signal type 2) import signal into the glycosome. In the present paper, we describe the biophysical characterization of a functional LPEX7 isolated from Escherichia coli inclusion bodies. Pull-down assays showed that LPEX7 binds the interacting partners LdPEX5 (Leishmania donovani peroxin 5) and LdPEX14, but, more importantly, this receptor can specifically bind PTS2 cargo proteins in the monomeric and dimeric states. However, in the absence of interacting partners, LPEX7 preferentially adopts a tetrameric structure. Mapping studies localized the LdPEX5- and LdPEX14-binding sites to the N-terminal portion of LPEX7. Deletion of the first 52 residues abolished LdPEX14 association without altering the LdPEX5 interaction. Intrinsic fluorescence techniques suggested that each LPEX7 subunit has a single unique binding site for each of the respective interacting partners LdPEX5, LdPEX14 and PTS2 cargo proteins. Extrinsic fluorescence studies with ANS (8-anilinonaphthalene-1-sulfonic acid) demonstrated that LPEX7 contains a surface-exposed hydrophobic region(s) that was not altered by the binding of a PTS2 protein or LdPEX5. However, in the presence of these ligands, the accessibility of the hydrophobic domain was dramatically restricted, suggesting that both ligands are necessary to induce notable conformational changes in LPEX7. In contrast, binding of LdPEX14 did not alter the hydrophobic domain on LPEX7. It is possible that the hydrophobic surfaces on LPEX7 may be a crucial characteristic for the shuttling of this receptor in and out of the glycosome.
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Metabolic reprogramming during purine stress in the protozoan pathogen Leishmania donovani. PLoS Pathog 2014; 10:e1003938. [PMID: 24586154 PMCID: PMC3937319 DOI: 10.1371/journal.ppat.1003938] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 01/06/2014] [Indexed: 01/18/2023] Open
Abstract
The ability of Leishmania to survive in their insect or mammalian host is dependent upon an ability to sense and adapt to changes in the microenvironment. However, little is known about the molecular mechanisms underlying the parasite response to environmental changes, such as nutrient availability. To elucidate nutrient stress response pathways in Leishmania donovani, we have used purine starvation as the paradigm. The salvage of purines from the host milieu is obligatory for parasite replication; nevertheless, purine-starved parasites can persist in culture without supplementary purine for over three months, indicating that the response to purine starvation is robust and engenders parasite survival under conditions of extreme scarcity. To understand metabolic reprogramming during purine starvation we have employed global approaches. Whole proteome comparisons between purine-starved and purine-replete parasites over a 6–48 h span have revealed a temporal and coordinated response to purine starvation. Purine transporters and enzymes involved in acquisition at the cell surface are upregulated within a few hours of purine removal from the media, while other key purine salvage components are upregulated later in the time-course and more modestly. After 48 h, the proteome of purine-starved parasites is extensively remodeled and adaptations to purine stress appear tailored to deal with both purine deprivation and general stress. To probe the molecular mechanisms affecting proteome remodeling in response to purine starvation, comparative RNA-seq analyses, qRT-PCR, and luciferase reporter assays were performed on purine-starved versus purine-replete parasites. While the regulation of a minority of proteins tracked with changes at the mRNA level, for many regulated proteins it appears that proteome remodeling during purine stress occurs primarily via translational and/or post-translational mechanisms. Leishmania, the cause of a deadly spectrum of diseases in humans, surmounts a number of environmental challenges, including changes in the availability of salvageable nutrients, to successfully colonize its host. Adaptation to environmental stress is clearly of significance in parasite biology, but the underlying mechanisms are not well understood. To simulate the response to periodic nutrient scarcity in vivo, we have induced purine starvation in vitro. Purines are essential for growth and viability, and serve as the major energy currency of cells. Leishmania cannot synthesize purines and must salvage them from the surroundings. Extracellular purine depletion in culture induces a robust survival response in Leishmania, whereby growth arrests, but parasites persist for months. To profile the events that enable endurance of purine starvation, we used shotgun proteomics. Our data suggest that purine starvation induces extensive proteome remodeling, tailored to enhance purine capture and recycling, reduce energy expenditures, and maintain viability of the metabolically active, non-dividing population. Through global and targeted approaches, we reveal that proteome remodeling is multifaceted, and occurs through an array of responses at the mRNA, translational, and post-translational level. Our data provide one of the most inclusive views of adaptation to microenvironmental stress in Leishmania.
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Environmentally regulated glycosome protein composition in the African trypanosome. EUKARYOTIC CELL 2013; 12:1072-9. [PMID: 23709182 DOI: 10.1128/ec.00086-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Trypanosomes compartmentalize many metabolic enzymes in glycosomes, peroxisome-related microbodies that are essential to parasite survival. While it is understood that these dynamic organelles undergo profound changes in protein composition throughout life cycle differentiation, the adaptations that occur in response to changes in environmental conditions are less appreciated. We have adopted a fluorescent-organelle reporter system in procyclic Trypanosoma brucei by expressing a fluorescent protein (FP) fused to a glycosomal targeting sequence (peroxisome-targeting sequence 2 [PTS2]). In these cell lines, PTS2-FP is localized within import-competent glycosomes, and organelle composition can be analyzed by microscopy and flow cytometry. Using this reporter system, we have characterized parasite populations that differ in their glycosome composition. In glucose-rich medium, two parasite populations are observed; one population harbors glycosomes bearing the full repertoire of glycosome proteins, while the other parasite population contains glycosomes that lack the usual glycosome-resident proteins but do contain the glycosome membrane protein TbPEX11. Interestingly, these cells lack TbPEX13, a protein essential for the import of proteins into the glycosome. This bimodal distribution is lost in low-glucose medium. Furthermore, we have demonstrated that changes in environmental conditions trigger changes in glycosome protein composition. These findings demonstrate a level of procyclic glycosome diversity heretofore unappreciated and offer a system by which glycosome dynamics can be studied in live cells. This work adds to our growing understanding of how the regulation of glycosome composition relates to environmental sensing.
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Sanchez LM, Knudsen GM, Hartmann C, De Muylder G, Mascuch SM, Mackey ZB, Gerwick L, Clayton C, McKerrow JH, Linington RG. Examination of the mode of action of the almiramide family of natural products against the kinetoplastid parasite Trypanosoma brucei. JOURNAL OF NATURAL PRODUCTS 2013; 76:630-41. [PMID: 23445522 PMCID: PMC3971013 DOI: 10.1021/np300834q] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Almiramide C is a marine natural product with low micromolar activity against Leishmania donovani, the causative agent of leishmaniasis. We have now shown that almiramide C is also active against the related parasite Trypanosoma brucei, the causative agent of human African trypanosomiasis. A series of activity-based probes have been synthesized to explore both the molecular target of this compound series in T. brucei lysates and site localization through epifluorescence microscopy. These target identification studies indicate that the almiramides likely perturb glycosomal function through disruption of membrane assembly machinery. Glycosomes, which are organelles specific to kinetoplastid parasites, house the first seven steps of glycolysis and have been shown to be essential for parasite survival in the bloodstream stage. There are currently no reported small-molecule disruptors of glycosome function, making the almiramides unique molecular probes for this understudied parasite-specific organelle. Additionally, examination of toxicity in an in vivo zebrafish model has shown that these compounds have little effect on organism development, even at high concentrations, and has uncovered a potential side effect through localization of fluorescent derivatives to zebrafish neuromast cells. Combined, these results further our understanding of the potential value of this lead series as development candidates against T. brucei.
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Affiliation(s)
- Laura M. Sanchez
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064
| | - Giselle M. Knudsen
- Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, CA 94143
| | - Claudia Hartmann
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), University of Heidelberg, Heidelberg, Heidelberg, Germany D-69120
| | - Geraldine De Muylder
- Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, CA 94143
| | - Samantha M. Mascuch
- Center for Marine Biotechnology and Biomedicine, Scripps Institute of Oceanography, University of California San Diego, San Diego, CA 92093
| | - Zachary B. Mackey
- Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, CA 94143
| | - Lena Gerwick
- Center for Marine Biotechnology and Biomedicine, Scripps Institute of Oceanography, University of California San Diego, San Diego, CA 92093
| | - Christine Clayton
- Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), University of Heidelberg, Heidelberg, Heidelberg, Germany D-69120
| | - James H. McKerrow
- Sandler Center for Drug Discovery, University of California San Francisco, San Francisco, CA 94143
| | - Roger G. Linington
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064
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Boitz JM, Strasser R, Yates PA, Jardim A, Ullman B. Adenylosuccinate synthetase and adenylosuccinate lyase deficiencies trigger growth and infectivity deficits in Leishmania donovani. J Biol Chem 2013; 288:8977-90. [PMID: 23404497 DOI: 10.1074/jbc.m112.431486] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leishmania are auxotrophic for purines, and consequently purine acquisition from the host is a requisite nutritional function for the parasite. Both adenylosuccinate synthetase (ADSS) and adenylosuccinate lyase (ASL) have been identified as vital components of purine salvage in Leishmania donovani, and therefore Δadss and Δasl null mutants were constructed to test this hypothesis. Unlike wild type L. donovani, Δadss and Δasl parasites in culture exhibited a profoundly restricted growth phenotype in which the only permissive growth conditions were a 6-aminopurine source in the presence of 2'-deoxycoformycin, an inhibitor of adenine aminohydrolase activity. Although both knock-outs showed a diminished capacity to infect murine peritoneal macrophages, only the Δasl null mutant was profoundly incapacitated in its ability to infect mice. The enormous discrepancy in parasite loads observed in livers and spleens from mice infected with either Δadss or Δasl parasites can be explained by selective accumulation of adenylosuccinate in the Δasl knock-out and consequent starvation for guanylate nucleotides. Genetic complementation of a Δasl lesion in Escherichia coli implied that the L. donovani ASL could also recognize 5-aminoimidazole-(N-succinylocarboxamide) ribotide as a substrate, and purified recombinant ASL displayed an apparent Km of ∼24 μm for adenylosuccinate. Unlike many components of the purine salvage pathway of L. donovani, both ASL and ADSS are cytosolic enzymes. Overall, these data underscore the paramount importance of ASL to purine salvage by both life cycle stages of L. donovani and authenticate ASL as a potential drug target in Leishmania.
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Affiliation(s)
- Jan M Boitz
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, OR 97239, USA
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Role of cytosolic glyceraldehyde-3-phosphate dehydrogenase in visceral organ infection by Leishmania donovani. EUKARYOTIC CELL 2012; 12:70-7. [PMID: 23125352 DOI: 10.1128/ec.00263-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The initial 7 steps of the glycolytic pathway from glucose to 3-phosphoglycerate are localized in the glycosomes in Leishmania, including step 6, catalyzed by the enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH). In L. donovani and L. mexicana, there exists a second GAPDH enzyme present in the cytosol that is absent in L. braziliensis and that has become a pseudogene in L. major. To investigate the role of the cytosolic GAPDH (cGAPDH), an L. donovani cGAPDH-null mutant was generated, and conversely, the functional L. donovani cGAPDH was introduced into L. major and the resulting engineered parasites were characterized. The L. donovani cGAPDH-null mutant was able to proliferate at the same rate as the wild-type parasite in glucose-deficient medium. However, in the presence of glucose, the L. donovani cGAPDH-null mutant consumed less glucose and proliferated more slowly than the wild-type parasite and displayed reduced infectivity in visceral organs of experimentally infected mice. This demonstrates that cGAPDH is functional in L. donovani and is required for survival in visceral organs. Restoration of cGAPDH activity in L. major, in contrast, had an adverse effect on L. major proliferation in glucose-containing medium, providing a possible explanation of why it has evolved into a pseudogene in L. major. This study indicates that there is a difference in glucose metabolism between L. donovani and L. major, and this may represent an important factor in the ability of L. donovani to cause visceral disease.
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Das A, Morales R, Banday M, Garcia S, Hao L, Cross GA, Estevez AM, Bellofatto V. The essential polysome-associated RNA-binding protein RBP42 targets mRNAs involved in Trypanosoma brucei energy metabolism. RNA (NEW YORK, N.Y.) 2012; 18:1968-1983. [PMID: 22966087 PMCID: PMC3479388 DOI: 10.1261/rna.033829.112] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 08/02/2012] [Indexed: 05/29/2023]
Abstract
RNA-binding proteins that target mRNA coding regions are emerging as regulators of post-transcriptional processes in eukaryotes. Here we describe a newly identified RNA-binding protein, RBP42, which targets the coding region of mRNAs in the insect form of the African trypanosome, Trypanosoma brucei. RBP42 is an essential protein and associates with polysome-bound mRNAs in the cytoplasm. A global survey of RBP42-bound mRNAs was performed by applying HITS-CLIP technology, which captures protein-RNA interactions in vivo using UV light. Specific RBP42-mRNA interactions, as well as mRNA interactions with a known RNA-binding protein, were purified using specific antibodies. Target RNA sequences were identified and quantified using high-throughput RNA sequencing. Analysis revealed that RBP42 bound mainly within the coding region of mRNAs that encode proteins involved in cellular energy metabolism. Although the mechanism of RBP42's function is unclear at present, we speculate that RBP42 plays a critical role in modulating T. brucei energy metabolism.
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Affiliation(s)
- Anish Das
- Department of Microbiology and Molecular Genetics, UMDNJ-NJ Medical School, Newark, New Jersey 07103, USA
| | - Rachel Morales
- Department of Microbiology and Molecular Genetics, UMDNJ-NJ Medical School, Newark, New Jersey 07103, USA
| | - Mahrukh Banday
- Department of Microbiology and Molecular Genetics, UMDNJ-NJ Medical School, Newark, New Jersey 07103, USA
| | - Stacey Garcia
- Department of Microbiology and Molecular Genetics, UMDNJ-NJ Medical School, Newark, New Jersey 07103, USA
| | - Li Hao
- Center for Genome Informatics, UMDNJ-NJ Medical School, Newark, New Jersey 07103, USA
| | | | - Antonio M. Estevez
- Instituto de Parasitologia y Biomedicina “Lopez-Neyra,” CSIC Avda. Del Comocimiento s/n. Armilla, 18100 Granada, Spain
| | - Vivian Bellofatto
- Department of Microbiology and Molecular Genetics, UMDNJ-NJ Medical School, Newark, New Jersey 07103, USA
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Lakhal-Naouar I, Jardim A, Strasser R, Luo S, Kozakai Y, Nakhasi HL, Duncan RC. Leishmania donovani argininosuccinate synthase is an active enzyme associated with parasite pathogenesis. PLoS Negl Trop Dis 2012; 6:e1849. [PMID: 23094117 PMCID: PMC3475689 DOI: 10.1371/journal.pntd.0001849] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Accepted: 08/22/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Gene expression analysis in Leishmania donovani (Ld) identified an orthologue of the urea cycle enzyme, argininosuccinate synthase (LdASS), that was more abundantly expressed in amastigotes than in promastigotes. In order to characterize in detail this newly identified protein in Leishmania, we determined its enzymatic activity, subcellular localization in the parasite and affect on virulence in vivo. METHODOLOGY/PRINCIPAL FINDINGS Two parasite cell lines either over expressing wild type LdASS or a mutant form (G128S) associated with severe cases of citrullinemia in humans were developed. In addition we also produced bacterially expressed recombinant forms of the same proteins. Our results demonstrated that LdASS has argininosuccinate synthase enzymatic activity that is abolished using an ASS specific inhibitor (MDLA: methyl-D-L-Aspartic acid). However, the mutant form of the protein is inactive. We demonstrate that though LdASS has a glycosomal targeting signal that binds the targeting apparatus in vitro, only a small proportion of the total cellular ASS is localized in a vesicle, as indicated by protection from protease digestion of the crude organelle fraction. The majority of LdASS was found to be in the cytosolic fraction that may include large cytosolic complexes as indicated by the punctate distribution in IFA. Surprisingly, comparison to known glycosomal proteins by IFA revealed that LdASS was located in a structure different from the known glycosomal vesicles. Significantly, parasites expressing a mutant form of LdASS associated with a loss of in vitro activity had reduced virulence in vivo in BALB/c mice as demonstrated by a significant reduction in the parasite load in spleen and liver. CONCLUSION/SIGNIFICANCE Our study suggests that LdASS is an active enzyme, with unique localization and essential for parasite survival and growth in the mammalian host. Based on these observations LdASS could be further explored as a potential drug target.
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Affiliation(s)
- Ines Lakhal-Naouar
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research (CBER), Food and Drug Administration (FDA), Bethesda, Maryland, United States of America
| | - Armando Jardim
- Institute of Parasitology, McGill University and the Centre for Host-Parasite Interactions, Quebec, Canada
| | - Rona Strasser
- Institute of Parasitology, McGill University and the Centre for Host-Parasite Interactions, Quebec, Canada
| | - Shen Luo
- Laboratory of Chemistry, Division of Therapeutic Proteins, Center for Drug Evaluation and Research (CDER), Food and Drug Administration (FDA), Bethesda, Maryland, United States of America
| | - Yukiko Kozakai
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research (CBER), Food and Drug Administration (FDA), Bethesda, Maryland, United States of America
| | - Hira L. Nakhasi
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research (CBER), Food and Drug Administration (FDA), Bethesda, Maryland, United States of America
| | - Robert C. Duncan
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research (CBER), Food and Drug Administration (FDA), Bethesda, Maryland, United States of America
- * E-mail:
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Gunasekera K, Wüthrich D, Braga-Lagache S, Heller M, Ochsenreiter T. Proteome remodelling during development from blood to insect-form Trypanosoma brucei quantified by SILAC and mass spectrometry. BMC Genomics 2012; 13:556. [PMID: 23067041 PMCID: PMC3545838 DOI: 10.1186/1471-2164-13-556] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 10/11/2012] [Indexed: 12/12/2022] Open
Abstract
Background Trypanosoma brucei is the causative agent of human African sleeping sickness and Nagana in cattle. In addition to being an important pathogen T. brucei has developed into a model system in cell biology. Results Using Stable Isotope Labelling of Amino acids in Cell culture (SILAC) in combination with mass spectrometry we determined the abundance of >1600 proteins in the long slender (LS), short stumpy (SS) mammalian bloodstream form stages relative to the procyclic (PC) insect-form stage. In total we identified 2645 proteins, corresponding to ~30% of the total proteome and for the first time present a comprehensive overview of relative protein levels in three life stages of the parasite. Conclusions We can show the extent of pre-adaptation in the SS cells, especially at the level of the mitochondrial proteome. The comparison to a previously published report on monomorphic in vitro grown bloodstream and procyclic T. brucei indicates a loss of stringent regulation particularly of mitochondrial proteins in these cells when compared to the pleomorphic in vivo situation. In order to better understand the different levels of gene expression regulation in this organism we compared mRNA steady state abundance with the relative protein abundance-changes and detected moderate but significant correlation indicating that trypanosomes possess a significant repertoire of translational and posttranslational mechanisms to regulate protein abundance.
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Boitz JM, Ullman B, Jardim A, Carter NS. Purine salvage in Leishmania: complex or simple by design? Trends Parasitol 2012; 28:345-52. [PMID: 22726696 DOI: 10.1016/j.pt.2012.05.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 05/22/2012] [Accepted: 05/23/2012] [Indexed: 11/19/2022]
Abstract
Purine nucleotides function in a variety of vital cellular and metabolic processes including energy production, cell signaling, synthesis of vitamin-derived cofactors and nucleic acids, and as determinants of cell fate. Unlike their mammalian and insect hosts, Leishmania cannot synthesize the purine ring de novo and are absolutely dependent upon them to meet their purine requirements. The obligatory nature of purine salvage in these parasites, therefore, offers an attractive paradigm for drug targeting and, consequently, the delineation of the pathway has been under scientific investigation for over 30 years. Here, we review recent developments that reveal how purines flux in Leishmania and offer a potential 'Achilles' heel' for future validation.
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Affiliation(s)
- Jan M Boitz
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, OR 97239, USA.
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Abstract
Protist parasites cause important human and animal diseases, and because of their early divergence from other eukaryotes they possess structural and biochemical characteristics not found in other cells. The completion of the genome projects of most human protist parasites and the development of novel molecular tools for their study guarantee a rapid progress in understanding how they invade, modify and survive within their hosts. The ultimate goal of these studies will be the identification of targets for the design of drugs, diagnostics and vaccines. In addition, the accessibility of some of these parasites to multiple genetic manipulations has converted them into model systems in cell and molecular biology studies that could lead to the understanding of basic biological processes, as well as their evolution and pathogenesis. In the present chapter we discuss the biochemical and molecular peculiarities of these parasites and the molecular tools available for their study.
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Boitz JM, Strasser R, Hartman CU, Jardim A, Ullman B. Adenine aminohydrolase from Leishmania donovani: unique enzyme in parasite purine metabolism. J Biol Chem 2012; 287:7626-39. [PMID: 22238346 DOI: 10.1074/jbc.m111.307884] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Adenine aminohydrolase (AAH) is an enzyme that is not present in mammalian cells and is found exclusively in Leishmania among the protozoan parasites that infect humans. AAH plays a paramount role in purine metabolism in this genus by steering 6-aminopurines into 6-oxypurines. Leishmania donovani AAH is 38 and 23% identical to Saccharomyces cerevisiae AAH and human adenosine deaminase enzymes, respectively, catalyzes adenine deamination to hypoxanthine with an apparent K(m) of 15.4 μM, and does not recognize adenosine as a substrate. Western blot analysis established that AAH is expressed in both life cycle stages of L. donovani, whereas subcellular fractionation and immunofluorescence studies confirmed that AAH is localized to the parasite cytosol. Deletion of the AAH locus in intact parasites established that AAH is not an essential gene and that Δaah cells are capable of salvaging the same range of purine nucleobases and nucleosides as wild type L. donovani. The Δaah null mutant was able to infect murine macrophages in vitro and in mice, although the parasite loads in both model systems were modestly reduced compared with wild type infections. The Δaah lesion was also introduced into a conditionally lethal Δhgprt/Δxprt mutant in which viability was dependent on pharmacologic ablation of AAH by 2'-deoxycoformycin. The Δaah/Δhgprt/Δxprt triple knock-out no longer required 2'-deoxycoformycin for growth and was avirulent in mice with no persistence after a 4-week infection. These genetic studies underscore the paramount importance of AAH to purine salvage by L. donovani.
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Affiliation(s)
- Jan M Boitz
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, Oregon 97239, USA
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Martín JF, Ullán RV, García-Estrada C. Role of peroxisomes in the biosynthesis and secretion of β-lactams and other secondary metabolites. J Ind Microbiol Biotechnol 2011; 39:367-82. [PMID: 22160272 DOI: 10.1007/s10295-011-1063-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 11/16/2011] [Indexed: 12/01/2022]
Abstract
Peroxisomes are eukaryotic organelles surrounded by a single bilayer membrane, containing a variety of proteins depending on the organism; they mainly perform degradation reactions of toxic metabolites (detoxification), catabolism of linear and branched-chain fatty acids, and removal of H(2)O(2) (formed in some oxidative processes) by catalase. Proteins named peroxins are involved in recruiting, transporting, and introducing the peroxisomal matrix proteins into the peroxisomes. The matrix proteins contain the peroxisomal targeting signals PTS1 and/or PTS2 that are recognized by the peroxins Pex5 and Pex7, respectively. Initial evidence indicated that the penicillin biosynthetic enzyme isopenicillin N acyltransferase (IAT) of Penicillium chrysogenum is located inside peroxisomes. There is now solid evidence (based on electron microscopy and/or biochemical data) confirming that IAT and the phenylacetic acid- and fatty acid-activating enzymes are also located in peroxisomes. Similarly, the Acremonium chrysogenum CefD1 and CefD2 proteins that perform the central reactions (activation and epimerization of isopenicillin N) of the cephalosporin pathway are targeted to peroxisomes. Growing evidence supports the conclusion that some enzymes involved in the biosynthesis of mycotoxins (e.g., AK-toxin), and the biosynthesis of signaling molecules in plants (e.g., jasmonic acid or auxins) occur in peroxisomes. The high concentration of substrates (in many cases toxic to the cytoplasm) and enzymes inside the peroxisomes allows efficient synthesis of metabolites with interesting biological or pharmacological activities. This compartmentalization poses additional challenges to the cell due to the need to import the substrates into the peroxisomes and to export the final products; the transporters involved in these processes are still very poorly known. This article focuses on new aspects of the metabolic processes occurring in peroxisomes, namely the degradation and detoxification processes that lead to the biosynthesis and secretion of secondary metabolites.
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Affiliation(s)
- Juan-Francisco Martín
- Área de Microbiología, Departamento de Biología Molecular, Universidad de León, León, Spain.
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Kaur J, Tiwari R, Kumar A, Singh N. Bioinformatic Analysis of Leishmania donovani Long-Chain Fatty Acid-CoA Ligase as a Novel Drug Target. Mol Biol Int 2011; 2011:278051. [PMID: 22091399 PMCID: PMC3198602 DOI: 10.4061/2011/278051] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 03/29/2011] [Accepted: 04/13/2011] [Indexed: 11/20/2022] Open
Abstract
Fatty acyl-CoA synthetase (fatty acid: CoA ligase, AMP-forming; (EC 6.2.1.3)) catalyzes the formation of fatty acyl-CoA by a two-step process that proceeds through the hydrolysis of pyrophosphate. Fatty acyl-CoA represents bioactive compounds that are involved in protein transport, enzyme activation, protein acylation, cell signaling, and transcriptional control in addition to serving as substrates for beta oxidation and phospholipid biosynthesis. Fatty acyl-CoA synthetase occupies a pivotal role in cellular homeostasis, particularly in lipid metabolism. Our interest in fatty acyl-CoA synthetase stems from the identification of this enzyme, long-chain fatty acyl-CoA ligase (LCFA) by microarray analysis. We found this enzyme to be differentially expressed by Leishmania donovani amastigotes resistant to antimonial treatment. In the present study, we confirm the presence of long-chain fatty acyl-CoA ligase gene in the genome of clinical isolates of Leishmania donovani collected from the disease endemic area in India. We predict a molecular model for this enzyme for in silico docking studies using chemical library available in our institute. On the basis of the data presented in this work, we propose that long-chain fatty acyl-CoA ligase enzyme serves as an important protein and a potential target candidate for development of selective inhibitors against leishmaniasis.
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Affiliation(s)
- Jaspreet Kaur
- Drug Target Discovery & Development Division, Central Drug Research Institute (CSIR), Chattar Manzil Palace, Lucknow 226001, India
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French JB, Yates PA, Soysa DR, Boitz JM, Carter NS, Chang B, Ullman B, Ealick SE. The Leishmania donovani UMP synthase is essential for promastigote viability and has an unusual tetrameric structure that exhibits substrate-controlled oligomerization. J Biol Chem 2011; 286:20930-41. [PMID: 21507942 PMCID: PMC3121495 DOI: 10.1074/jbc.m111.228213] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 03/30/2011] [Indexed: 11/06/2022] Open
Abstract
The final two steps of de novo uridine 5'-monophosphate (UMP) biosynthesis are catalyzed by orotate phosphoribosyltransferase (OPRT) and orotidine 5'-monophosphate decarboxylase (OMPDC). In most prokaryotes and simple eukaryotes these two enzymes are encoded by separate genes, whereas in mammals they are expressed as a bifunctional gene product called UMP synthase (UMPS), with OPRT at the N terminus and OMPDC at the C terminus. Leishmania and some closely related organisms also express a bifunctional enzyme for these two steps, but the domain order is reversed relative to mammalian UMPS. In this work we demonstrate that L. donovani UMPS (LdUMPS) is an essential enzyme in promastigotes and that it is sequestered in the parasite glycosome. We also present the crystal structure of the LdUMPS in complex with its product, UMP. This structure reveals an unusual tetramer with two head to head and two tail to tail interactions, resulting in two dimeric OMPDC and two dimeric OPRT functional domains. In addition, we provide structural and biochemical evidence that oligomerization of LdUMPS is controlled by product binding at the OPRT active site. We propose a model for the assembly of the catalytically relevant LdUMPS tetramer and discuss the implications for the structure of mammalian UMPS.
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Affiliation(s)
- Jarrod B. French
- From the Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853 and
| | - Phillip A. Yates
- the Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon 97239
| | - D. Radika Soysa
- the Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon 97239
| | - Jan M. Boitz
- the Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon 97239
| | - Nicola S. Carter
- the Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon 97239
| | - Bailey Chang
- From the Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853 and
| | - Buddy Ullman
- the Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon 97239
| | - Steven E. Ealick
- From the Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853 and
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Swenerton RK, Knudsen GM, Sajid M, Kelly BL, McKerrow JH. Leishmania subtilisin is a maturase for the trypanothione reductase system and contributes to disease pathology. J Biol Chem 2010; 285:31120-9. [PMID: 20675366 DOI: 10.1074/jbc.m110.114462] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Proteases are a ubiquitous group of enzymes that play key roles in the life cycle of parasites, in the host-parasite relationship, and in the pathogenesis of parasitic diseases. Furthermore, proteases are druggable targets for the development of new anti-parasitic therapy. The subtilisin protease (SUB; Clan SB, family S8) of Leishmania donovani was cloned and found to possess a unique catalytic triad. This gene was then deleted by gene knock-out, which resulted in reduced ability by the parasite to undergo promastigote to amastigote differentiation in vitro. Electron microscopy of SUB knock-out amastigotes revealed abnormal membrane structures, retained flagella, and increased binucleation. SUB-deficient Leishmania displayed reduced virulence in both hamster and murine infection models. Histology of spleens from SUB knock-out-infected hamsters revealed the absence of psammoma body calcifications indicative of the granulomatous lesions that occur during Leishmania infection. To delineate the specific role of SUB in parasite physiology, two-dimensional gel electrophoresis was carried out on SUB(-/-) versus wild-type parasites. SUB knock-out parasites showed altered regulation of the terminal peroxidases of the trypanothione reductase system. Leishmania and other trypanosomatids lack glutathione reductase, and therefore rely on the novel trypanothione reductase system to detoxify reactive oxygen intermediates and to maintain redox homeostasis. The predominant tryparedoxin peroxidases were decreased in SUB(-/-) parasites, and higher molecular weight isoforms were present, indicating altered processing. In addition, knock-out parasites showed increased sensitivity to hydroperoxide. These data suggest that subtilisin is the maturase for tryparedoxin peroxidases and is necessary for full virulence.
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Affiliation(s)
- Ryan K Swenerton
- Department of Pathology, Sandler Center for Drug Discovery, University of California, San Francisco, California 94158, USA
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Holzmuller P, Grébaut P, Cuny G, Biron DG. Tsetse flies, trypanosomes, humans and animals: what is proteomics revealing about their crosstalks? Expert Rev Proteomics 2010; 7:113-26. [PMID: 20121481 DOI: 10.1586/epr.09.92] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Human and animal African trypanosomoses, or sleeping sickness and Nagana, are neglected vector-borne parasitic diseases caused by protozoa belonging to the Trypanosoma genus. Advances in proteomics offer new tools to better understand host-vector-parasite crosstalks occurring during the complex parasitic developmental cycle, and to determine the outcome of both transmission and infection. In this review, we summarize proteomics studies performed on African trypanosomes and on the interactions with their vector and mammalian hosts. We discuss the contributions and pitfalls of using diverse proteomics tools, and argue about the interest of pathogenoproteomics, both to generate advances in basic research on the best knowledge and understanding of host-vector-pathogen interactions, and to lead to the concrete development of new tools to improve diagnosis and treatment management of trypanosomoses in the near future.
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Affiliation(s)
- Philippe Holzmuller
- CIRAD UMR 17 Trypanosomes, UMR 177 IRD-CIRAD Interactions Hôtes-Vecteurs-Parasites dans les Trypanosomoses, TA A-17/G, Campus International de Baillarguet, 34398 Montpellier cedex 5, France.
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Abstract
African trypanosomes have emerged as promising unicellular model organisms for the next generation of systems biology. They offer unique advantages, due to their relative simplicity, the availability of all standard genomics techniques and a long history of quantitative research. Reproducible cultivation methods exist for morphologically and physiologically distinct life-cycle stages. The genome has been sequenced, and microarrays, RNA-interference and high-accuracy metabolomics are available. Furthermore, the availability of extensive kinetic data on all glycolytic enzymes has led to the early development of a complete, experiment-based dynamic model of an important biochemical pathway. Here we describe the achievements of trypanosome systems biology so far and outline the necessary steps towards the ambitious aim of creating a 'Silicon Trypanosome', a comprehensive, experiment-based, multi-scale mathematical model of trypanosome physiology. We expect that, in the long run, the quantitative modelling enabled by the Silicon Trypanosome will play a key role in selecting the most suitable targets for developing new anti-parasite drugs.
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Sprehe M, Fisk JC, McEvoy SM, Read LK, Schumacher MA. Structure of the Trypanosoma brucei p22 protein, a cytochrome oxidase subunit II-specific RNA-editing accessory factor. J Biol Chem 2010; 285:18899-908. [PMID: 20392699 PMCID: PMC2881812 DOI: 10.1074/jbc.m109.066597] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Kinetoplastid RNA (k-RNA) editing is a complex process in the mitochondria of kinetoplastid protozoa, including Trypanosoma brucei, that involves the guide RNA-directed insertion and deletion of uridines from precursor-mRNAs to produce mature, translatable mRNAs. k-RNA editing is performed by multiprotein complexes called editosomes. Additional non-editosome components termed k-RNA-editing accessory factors affect the extent of editing of specific RNAs or classes of RNAs. The T. brucei p22 protein was identified as one such accessory factor. Here we show that p22 contributes to cell growth in the procyclic form of T. brucei and functions as a cytochrome oxidase subunit II-specific k-RNA-editing accessory factor. To gain insight into its functions, we solved the crystal structure of the T. brucei p22 protein to 2.0-A resolution. The p22 structure consists of a six-stranded, antiparallel beta-sheet flanked by five alpha-helices. Three p22 subunits combine to form a tight trimer that is primarily stabilized by interactions between helical residues. One side of the trimer is strikingly acidic, while the opposite face is more neutral. Database searches show p22 is structurally similar to human p32, which has a number of functions, including regulation of RNA splicing. p32 interacts with a number of target proteins via its alpha1 N-terminal helix, which is among the most conserved regions between p22 and p32. Co-immunoprecipitation studies showed that p22 interacts with the editosome and the k-RNA accessory protein, TbRGG2, and alpha1 of p22 was shown to be important for the p22-TbRGG2 interaction. Thus, these combined studies suggest that p22 mediates its role in k-RNA editing by acting as an adaptor protein.
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Affiliation(s)
- Mareen Sprehe
- Department of Biochemistry and Molecular Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA
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Identification, characterization and essentiality of the unusual peroxin 13 from Trypanosoma brucei. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:516-27. [PMID: 19185591 DOI: 10.1016/j.bbamcr.2008.12.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 12/08/2008] [Accepted: 12/18/2008] [Indexed: 11/20/2022]
Abstract
Peroxin 13 (PEX13) is one of the components of a peroxisomal membrane complex involved in import of proteins into the matrix of the organelles and has previously been characterized in a variety of organisms. Trypanosomatids (Trypanosoma, Leishmania), protozoan parasites having peroxisome-like organelles designated glycosomes, possess an unusual PEX13 which shares very low sequence identity with others and lacks some typical PEX13 characteristics. It was identified in the databases through its multiple YGx motifs present in a glycine-rich N-terminal region of low sequence complexity. Like other PEX13s, it contains predicted transmembrane segments and a SH3 domain in its C-terminal half. The localization of T. brucei PEX13 in the glycosomal membrane was confirmed by expression of a fusion construct with Green Fluorescent Protein, and western blot analysis of purified organelles and membranes. The C-terminal half of the protein was shown to interact with the third of three pentapeptide repeats of the previously characterized PEX5, the receptor of glycosomal proteins with a type 1 peroxisome-targeting signal, and with PEX14, another component of the same peroxisomal protein import complex in the membrane. PEX13 is essential for the parasite; depletion by RNA interference results in mislocalization of glycosomal proteins and death of the parasites.
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Abstract
Protein kinase A (PKA) is an important mediator of many signal transduction pathways that occur in eukaryotic cells, and it has been implicated as a regulator of stage differentiation in Trypanosoma cruzi. To evaluate the importance of the PKA catalytic subunit of T. cruzi (TcPKAc), a gene encoding a PKA inhibitor (PKI) containing a specific PKA pseudosubstrate, R-R-N-A, was subcloned into a pTREX vector and introduced into epimastigotes by electroporation. Expression of PKI has a lethal effect in this parasite. Similarly, a pharmacological inhibitor, H89, killed epimastigotes at a concentration of 10 muM. To understand the biology of PKA, identification of the particular substrates of this enzyme is essential. Using a yeast two-hybrid system, 38 candidates interacting with TcPKAc were identified. Eighteen of these were hypothetical proteins with unknown functions, while the others had putative or known functions. The entire open reading frames of eight genes presumably important in regulating T. cruzi growth, adaptation, and differentiation, including a type III PI3 kinase (Vps34), a putative PI3 kinase, a putative mitogen-activated extracellular signal-regulated kinase, a cyclic AMP (cAMP)-specific phosphodiesterase (PDEC2), a hexokinase, a putative ATPase, a DNA excision repair protein, and an aquaporin were confirmed to interact with TcPKAc in the yeast Saccharomyces cerevisiae under the highest stringency selection conditions, and PKA phosphorylated the recombinant proteins of these genes. Taken together, these findings demonstrate the importance of cAMP-PKA signaling in this organism.
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Vonlaufen N, Kanzok SM, Wek RC, Sullivan WJ. Stress response pathways in protozoan parasites. Cell Microbiol 2008; 10:2387-99. [PMID: 18647172 DOI: 10.1111/j.1462-5822.2008.01210.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Diseases caused by protozoan parasites have a dramatic impact on world health. Emerging drug resistance and a general lack of experimental understanding has created a void in the medicine cabinet used to treat these widespread infections. A novel therapeutic idea that is receiving more attention is centred on targeting the microbe's response to the multitude of environmental stresses it encounters. Protozoan pathogens have complex life cycles, often having to transition from one host to another, or survive in a cyst form in the environment until a new host arrives. The need to respond to environmental cues and stress, and endure in less than optimal conditions, is paramount to their viability and successful progression through their life cycle. This review summarizes the research on parasitic stress responses for Apicomplexa, kinetoplastids and anaerobic protozoa, with an eye towards how these processes may be exploited therapeutically.
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Affiliation(s)
- Nathalie Vonlaufen
- Departments of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA
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Clark CG, Alsmark UCM, Tazreiter M, Saito-Nakano Y, Ali V, Marion S, Weber C, Mukherjee C, Bruchhaus I, Tannich E, Leippe M, Sicheritz-Ponten T, Foster PG, Samuelson J, Noël CJ, Hirt RP, Embley TM, Gilchrist CA, Mann BJ, Singh U, Ackers JP, Bhattacharya S, Bhattacharya A, Lohia A, Guillén N, Duchêne M, Nozaki T, Hall N. Structure and content of the Entamoeba histolytica genome. ADVANCES IN PARASITOLOGY 2008; 65:51-190. [PMID: 18063096 DOI: 10.1016/s0065-308x(07)65002-7] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The intestinal parasite Entamoeba histolytica is one of the first protists for which a draft genome sequence has been published. Although the genome is still incomplete, it is unlikely that many genes are missing from the list of those already identified. In this chapter we summarise the features of the genome as they are currently understood and provide previously unpublished analyses of many of the genes.
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Affiliation(s)
- C G Clark
- Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
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Saveria T, Halbach A, Erdmann R, Volkmer-Engert R, Landgraf C, Rottensteiner H, Parsons M. Conservation of PEX19-binding motifs required for protein targeting to mammalian peroxisomal and trypanosome glycosomal membranes. EUKARYOTIC CELL 2007; 6:1439-49. [PMID: 17586720 PMCID: PMC1951143 DOI: 10.1128/ec.00084-07] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glycosomes are divergent peroxisomes found in trypanosomatid protozoa, including those that cause severe human diseases throughout much of the world. While peroxisomes are dispensable for both yeast (Saccharomyces cerevisiae and others) and mammalian cells in vitro, glycosomes are essential for trypanosomes and hence are viewed as a potential drug target. The import of proteins into the matrix of peroxisomes utilizes multiple peroxisomal membrane proteins which require the peroxin PEX19 for insertion into the peroxisomal membrane. In this report, we show that the specificity of peroxisomal membrane protein binding for Trypanosoma brucei PEX19 is very similar to those previously identified for human and yeast PEX19. Our studies show that trafficking is conserved across these distant phyla and that both a PEX19 binding site and a transmembrane domain are required for the insertion of two test proteins into the glycosomal membrane. However, in contrast to T. brucei PEX10 and PEX12, T. brucei PEX14 does not traffic to human peroxisomes, indicating that it is not recognized by the human PEX14 import mechanism.
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Affiliation(s)
- Tracy Saveria
- Seattle Biomedical Research Institute, Seattle, WA 98109, USA
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