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Mahadevan L, Arya H, Droste A, Schliebs W, Erdmann R, Kalel VC. PEX1 is essential for glycosome biogenesis and trypanosomatid parasite survival. Front Cell Infect Microbiol 2024; 14:1274506. [PMID: 38510966 PMCID: PMC10952002 DOI: 10.3389/fcimb.2024.1274506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 02/09/2024] [Indexed: 03/22/2024] Open
Abstract
Trypanosomatid parasites are kinetoplastid protists that compartmentalize glycolytic enzymes in unique peroxisome-related organelles called glycosomes. The heterohexameric AAA-ATPase complex of PEX1-PEX6 is anchored to the peroxisomal membrane and functions in the export of matrix protein import receptor PEX5 from the peroxisomal membrane. Defects in PEX1, PEX6 or their membrane anchor causes dysfunction of peroxisomal matrix protein import cycle. In this study, we functionally characterized a putative Trypanosoma PEX1 orthologue by bioinformatic and experimental approaches and show that it is a true PEX1 orthologue. Using yeast two-hybrid analysis, we demonstrate that TbPEX1 can bind to TbPEX6. Endogenously tagged TbPEX1 localizes to glycosomes in the T. brucei parasites. Depletion of PEX1 gene expression by RNA interference causes lethality to the bloodstream form trypanosomes, due to a partial mislocalization of glycosomal enzymes to the cytosol and ATP depletion. TbPEX1 RNAi leads to a selective proteasomal degradation of both matrix protein import receptors TbPEX5 and TbPEX7. Unlike in yeast, PEX1 depletion did not result in an accumulation of ubiquitinated TbPEX5 in trypanosomes. As PEX1 turned out to be essential for trypanosomatid parasites, it could provide a suitable drug target for parasitic diseases. The results also suggest that these parasites possess a highly efficient quality control mechanism that exports the import receptors from glycosomes to the cytosol in the absence of a functional TbPEX1-TbPEX6 complex.
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Affiliation(s)
| | | | | | | | - Ralf Erdmann
- Department of Systems Biochemistry, Faculty of Medicine, Institute for Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
| | - Vishal C. Kalel
- Department of Systems Biochemistry, Faculty of Medicine, Institute for Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
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Lukeš J, Speijer D, Zíková A, Alfonzo JD, Hashimi H, Field MC. Trypanosomes as a magnifying glass for cell and molecular biology. Trends Parasitol 2023; 39:902-912. [PMID: 37679284 DOI: 10.1016/j.pt.2023.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 09/09/2023]
Abstract
The African trypanosome, Trypanosoma brucei, has developed into a flexible and robust experimental model for molecular and cellular parasitology, allowing us to better combat these and related parasites that cause worldwide suffering. Diminishing case numbers, due to efficient public health efforts, and recent development of new drug treatments have reduced the need for continued study of T. brucei in a disease context. However, we argue that this pathogen has been instrumental in revolutionary discoveries that have widely informed molecular and cellular biology and justifies continuing research as an experimental model. Ongoing work continues to contribute towards greater understanding of both diversified and conserved biological features. We discuss multiple examples where trypanosomes pushed the boundaries of cell biology and hope to inspire researchers to continue exploring these remarkable protists as tools for magnifying the inner workings of cells.
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Affiliation(s)
- Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic.
| | - Dave Speijer
- Medical Biochemistry, University of Amsterdam, AMC, Amsterdam, The Netherlands
| | - Alena Zíková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Juan D Alfonzo
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Hassan Hashimi
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic; Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Mark C Field
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic; School of Life Sciences, University of Dundee, Dundee, UK
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Krishna CK, Schmidt N, Tippler BG, Schliebs W, Jung M, Winklhofer KF, Erdmann R, Kalel VC. Molecular basis of the glycosomal targeting of PEX11 and its mislocalization to mitochondrion in trypanosomes. Front Cell Dev Biol 2023; 11:1213761. [PMID: 37664461 PMCID: PMC10469627 DOI: 10.3389/fcell.2023.1213761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/03/2023] [Indexed: 09/05/2023] Open
Abstract
PEX19 binding sites are essential parts of the targeting signals of peroxisomal membrane proteins (mPTS). In this study, we characterized PEX19 binding sites of PEX11, the most abundant peroxisomal and glycosomal membrane protein from Trypanosoma brucei and Saccharomyces cerevisiae. TbPEX11 contains two PEX19 binding sites, one close to the N-terminus (BS1) and a second in proximity to the first transmembrane domain (BS2). The N-terminal BS1 is highly conserved across different organisms and is required for maintenance of the steady-state concentration and efficient targeting to peroxisomes and glycosomes in both baker's yeast and Trypanosoma brucei. The second PEX19 binding site in TbPEX11 is essential for its glycosomal localization. Deletion or mutations of the PEX19 binding sites in TbPEX11 or ScPEX11 results in mislocalization of the proteins to mitochondria. Bioinformatic analysis indicates that the N-terminal region of TbPEX11 contains an amphiphilic helix and several putative TOM20 recognition motifs. We show that the extreme N-terminal region of TbPEX11 contains a cryptic N-terminal signal that directs PEX11 to the mitochondrion if its glycosomal transport is blocked.
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Affiliation(s)
- Chethan K. Krishna
- Department of Systems Biochemistry, Institute for Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
| | - Nadine Schmidt
- Department of Systems Biochemistry, Institute for Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
| | - Bettina G. Tippler
- Department of Systems Biochemistry, Institute for Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
| | - Wolfgang Schliebs
- Department of Systems Biochemistry, Institute for Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
| | - Martin Jung
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Homburg, Germany
| | - Konstanze F. Winklhofer
- Department Molecular Cell Biology, Institute of Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
| | - Ralf Erdmann
- Department of Systems Biochemistry, Institute for Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
| | - Vishal C. Kalel
- Department of Systems Biochemistry, Institute for Biochemistry and Pathobiochemistry, Faculty of Medicine, Ruhr University Bochum, Bochum, Germany
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4
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Morales J, Ehret G, Poschmann G, Reinicke T, Maurya AK, Kröninger L, Zanini D, Wolters R, Kalyanaraman D, Krakovka M, Bäumers M, Stühler K, Nowack ECM. Host-symbiont interactions in Angomonas deanei include the evolution of a host-derived dynamin ring around the endosymbiont division site. Curr Biol 2023; 33:28-40.e7. [PMID: 36480982 DOI: 10.1016/j.cub.2022.11.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/09/2022] [Accepted: 11/09/2022] [Indexed: 12/12/2022]
Abstract
The trypanosomatid Angomonas deanei is a model to study endosymbiosis. Each cell contains a single β-proteobacterial endosymbiont that divides at a defined point in the host cell cycle and contributes essential metabolites to the host metabolism. Additionally, one endosymbiont gene, encoding an ornithine cyclodeaminase (OCD), was transferred by endosymbiotic gene transfer (EGT) to the nucleus. However, the molecular mechanisms mediating the intricate host/symbiont interactions are largely unexplored. Here, we used protein mass spectrometry to identify nucleus-encoded proteins that co-purify with the endosymbiont. Expression of fluorescent fusion constructs of these proteins in A. deanei confirmed seven host proteins to be recruited to specific sites within the endosymbiont. These endosymbiont-targeted proteins (ETPs) include two proteins annotated as dynamin-like protein and peptidoglycan hydrolase that form a ring-shaped structure around the endosymbiont division site that remarkably resembles organellar division machineries. The EGT-derived OCD was not among the ETPs, but instead localizes to the glycosome, likely enabling proline production in the glycosome. We hypothesize that recalibration of the metabolic capacity of the glycosomes that are closely associated with the endosymbiont helps to supply the endosymbiont with metabolites it is auxotrophic for and thus supports the integration of host and endosymbiont metabolic networks. Hence, scrutiny of endosymbiosis-induced protein re-localization patterns in A. deanei yielded profound insights into how an endosymbiotic relationship can stabilize and deepen over time far beyond the level of metabolite exchange.
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Affiliation(s)
- Jorge Morales
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Georg Ehret
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Gereon Poschmann
- Institute of Molecular Medicine, Proteome Research, Medical Faculty and University Hospital, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Tobias Reinicke
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Anay K Maurya
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Lena Kröninger
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Davide Zanini
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Rebecca Wolters
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Dhevi Kalyanaraman
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Michael Krakovka
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Miriam Bäumers
- Center for Advanced Imaging, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Kai Stühler
- Institute of Molecular Medicine, Proteome Research, Medical Faculty and University Hospital, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany; Molecular Proteomics Laboratory, Biological and Medical Research Centre (BMFZ), Heinrich Heine University Düsseldorf, Universitätsstr 1, 40225 Düsseldorf, Germany
| | - Eva C M Nowack
- Institute of Microbial Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany.
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Banerjee H, LaPointe P, Eitzen G, Rachubinski RA. A Small Molecule Inhibitor of Pex3-Pex19 Interaction Disrupts Glycosome Biogenesis and Causes Lethality in Trypanosoma brucei. Front Cell Dev Biol 2021; 9:703603. [PMID: 34350186 PMCID: PMC8326762 DOI: 10.3389/fcell.2021.703603] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/22/2021] [Indexed: 11/29/2022] Open
Abstract
Trypanosomatid parasites, including Trypanosoma and Leishmania, are infectious zoonotic agents for a number of severe diseases such as African sleeping sickness and American trypanosomiasis (Chagas disease) that affect millions of people, mostly in the emergent world. The glycosome is a specialized member of the peroxisome family of organelles found in trypanosomatids. These organelles compartmentalize essential enzymes of the glycolytic pathway, making them a prime target for drugs that can kill these organisms by interfering with either their biochemical functions or their formation. Glycosome biogenesis, like peroxisome biogenesis, is controlled by a group of proteins called peroxins (Pex). Pex3 is an early acting peroxin that docks Pex19, the receptor for peroxisomal membrane proteins, to initiate biogenesis of peroxisomes from the endoplasmic reticulum. Identification of Pex3 as the essential master regulator of glycosome biogenesis has implications in developing small molecule inhibitors that can impede Pex3–Pex19 interaction. Low amino acid sequence conservation between trypanosomatid Pex3 and human Pex3 (HsPex3) would aid in the identification of small molecule inhibitors that selectively interfere with the trypanosomatid Pex3–Pex19 interaction. We tested a library of pharmacologically active compounds in a modified yeast two-hybrid assay and identified a compound that preferentially inhibited the interaction of Trypanosoma brucei Pex3 and Pex19 versus HsPex3 and Pex19. Addition of this compound to either the insect or bloodstream form of T. brucei disrupted glycosome biogenesis, leading to mislocalization of glycosomal enzymes to the cytosol and lethality for the parasite. Our results show that preferential disruption of trypanosomal Pex3 function by small molecule inhibitors could help in the accelerated development of drugs for the treatment of trypanosomiases.
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Affiliation(s)
- Hiren Banerjee
- Department of Cell Biology, University of Alberta, Edmonton, AB, Canada
| | - Paul LaPointe
- Department of Cell Biology, University of Alberta, Edmonton, AB, Canada
| | - Gary Eitzen
- Department of Cell Biology, University of Alberta, Edmonton, AB, Canada
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Schenk R, Bachmaier S, Bringaud F, Boshart M. Efficient flavinylation of glycosomal fumarate reductase by its own ApbE domain in Trypanosoma brucei. FEBS J 2021; 288:5430-5445. [PMID: 33755328 DOI: 10.1111/febs.15812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/08/2021] [Accepted: 03/09/2021] [Indexed: 01/26/2023]
Abstract
A subset of flavoproteins has a covalently attached flavin prosthetic group enzymatically attached via phosphoester bonding. In prokaryotes, this is catalysed by alternative pyrimidine biosynthesis E (ApbE) flavin transferases. ApbE-like domains are present in few eukaryotic taxa, for example the N-terminal domain of fumarate reductase (FRD) of Trypanosoma, a parasitic protist known as a tropical pathogen causing African sleeping sickness. We use the versatile reverse genetic tools available for Trypanosoma to investigate the flavinylation of glycosomal FRD (FRDg) in vivo in the physiological and organellar context. Using direct in-gel fluorescence detection of covalently attached flavin as proxy for activity, we show that the ApbE-like domain of FRDg has flavin transferase activity in vivo. The ApbE domain is preceded by a consensus flavinylation target motif at the extreme N terminus of FRDg, and serine 9 in this motif is essential as flavin acceptor. The preferred mode of flavinylation in the glycosome was addressed by stoichiometric expression and comparison of native and catalytically inactive ApbE domains. In addition to the trans-flavinylation activity, the ApbE domain catalyses the intramolecular cis-flavinylation with at least fivefold higher efficiency. We discuss how the higher efficiency due to unusual fusion of the ApbE domain to its substrate protein FRD may provide a selective advantage by faster FRD biogenesis during rapid metabolic adaptation of trypanosomes. The first 37 amino acids of FRDg, including the consensus motif, are sufficient as flavinylation target upon fusion to other proteins. We propose FRDg(1-37) as 4-kDa heat-stable, detergent-resistant fluorescent protein tag and suggest its use as a new tool to study glycosomal protein import.
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Affiliation(s)
- Robin Schenk
- Biozentrum, Fakultät für Biologie, Genetik, Ludwig-Maximilians-Universität München (LMU), Martinsried, Germany
| | - Sabine Bachmaier
- Biozentrum, Fakultät für Biologie, Genetik, Ludwig-Maximilians-Universität München (LMU), Martinsried, Germany
| | - Frédéric Bringaud
- CNRS, Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234, Université de Bordeaux, France
| | - Michael Boshart
- Biozentrum, Fakultät für Biologie, Genetik, Ludwig-Maximilians-Universität München (LMU), Martinsried, Germany
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Crowe LP, Wilkinson CL, Nicholson KR, Morris MT. Trypanosoma brucei Pex13.2 Is an Accessory Peroxin That Functions in the Import of Peroxisome Targeting Sequence Type 2 Proteins and Localizes to Subdomains of the Glycosome. mSphere 2020; 5:e00744-19. [PMID: 32075879 PMCID: PMC7031615 DOI: 10.1128/msphere.00744-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/30/2020] [Indexed: 01/30/2023] Open
Abstract
Kinetoplastid parasites, including Trypanosoma brucei, Trypanosoma cruzi, and Leishmania, harbor unique organelles known as glycosomes, which are evolutionarily related to peroxisomes. Glycosome/peroxisome biogenesis is mediated by proteins called peroxins that facilitate organelle formation, proliferation, and degradation and import of proteins housed therein. Import of matrix proteins occurs via one of two pathways that are dictated by their peroxisome targeting sequence (PTS). In PTS1 import, a C-terminal tripeptide sequence, most commonly SKL, is recognized by the soluble receptor Pex5. In PTS2 import, a less conserved N-terminal sequence is recognized by Pex7. The soluble receptors deliver their cargo to the import channel consisting minimally of Pex13 and Pex14. While much of the import process is conserved, kinetoplastids are the only organisms to have two Pex13s, Pex13.1 and Pex13.2. It is unclear why trypanosomes require two Pex13s when one is sufficient for most eukaryotes. To interrogate the role of Pex13.2, we have employed biochemical approaches to partially resolve the composition of the Pex13/Pex14 import complexes in T. brucei and characterized glycosome morphology and protein import in Pex13.2-deficient parasites. Here, we show that Pex13.2 is an integral glycosome membrane protein that interacts with Pex13.1 and Pex14. The N terminus of Pex13.2 faces the cytoplasmic side of the membrane, where it can facilitate interactions required for protein import. Two-dimensional gel electrophoresis revealed three glycosome membrane complexes containing combinations of Pex13.1, Pex13.2, and Pex14. The silencing of Pex13.2 resulted in parasites with fewer, larger glycosomes and disrupted glycosome protein import, suggesting the protein is involved in glycosome biogenesis as well as protein import. Furthermore, superresolution microscopy demonstrated that Pex13.2 localizes to discrete foci in the glycosome periphery, indicating that the glycosome periphery is not homogenous.IMPORTANCETrypanosoma brucei causes human African trypanosomiasis and a wasting disease called Nagana in livestock. Current treatments are expensive, toxic, and difficult to administer. Because of this, the search for new drug targets is essential. T. brucei has glycosomes that are essential to parasite survival; however, our ability to target them in drug development is hindered by our lack of understanding about how these organelles are formed and maintained. This work forwards our understanding of how the parasite-specific protein Pex13.2 functions in glycosome protein import and lays the foundation for future studies focused on blocking Pex13.2 function, which would be lethal to bloodstream-form parasites that reside in the mammalian bloodstream.
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Affiliation(s)
- Logan P Crowe
- Eukaryotic Innovations Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
| | - Christina L Wilkinson
- Eukaryotic Innovations Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
| | - Kathleen R Nicholson
- Eukaryotic Innovations Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
| | - Meredith T Morris
- Eukaryotic Innovations Center, Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
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Szöőr B, Simon DV, Rojas F, Young J, Robinson DR, Krüger T, Engstler M, Matthews KR. Positional Dynamics and Glycosomal Recruitment of Developmental Regulators during Trypanosome Differentiation. mBio 2019; 10:e00875-19. [PMID: 31289175 DOI: 10.1128/mBio.00875-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
African trypanosomes are parasites of sub-Saharan Africa responsible for both human and animal disease. The parasites are transmitted by tsetse flies, and completion of their life cycle involves progression through several development steps. The initiation of differentiation between blood and tsetse fly forms is signaled by a phosphatase cascade, ultimately trafficked into peroxisome-related organelles called glycosomes that are unique to this group of organisms. Glycosomes undergo substantial remodeling of their composition and function during the differentiation step, but how this is regulated is not understood. Here we identify a cytological site where the signaling molecules controlling differentiation converge before the dispersal of one of them into glycosomes. In combination, the study provides the first insight into the spatial coordination of signaling pathway components in trypanosomes as they undergo cell-type differentiation. Glycosomes are peroxisome-related organelles that compartmentalize the glycolytic enzymes in kinetoplastid parasites. These organelles are developmentally regulated in their number and composition, allowing metabolic adaptation to the parasite’s needs in the blood of mammalian hosts or within their arthropod vector. A protein phosphatase cascade regulates differentiation between parasite developmental forms, comprising a tyrosine phosphatase, Trypanosoma brucei PTP1 (TbPTP1), which dephosphorylates and inhibits a serine threonine phosphatase, TbPIP39, which promotes differentiation. When TbPTP1 is inactivated, TbPIP39 is activated and during differentiation becomes located in glycosomes. Here we have tracked TbPIP39 recruitment to glycosomes during differentiation from bloodstream “stumpy” forms to procyclic forms. Detailed microscopy and live-cell imaging during the synchronous transition between life cycle stages revealed that in stumpy forms, TbPIP39 is located at a periflagellar pocket site closely associated with TbVAP, which defines the flagellar pocket endoplasmic reticulum. TbPTP1 is also located at the same site in stumpy forms, as is REG9.1, a regulator of stumpy-enriched mRNAs. This site provides a molecular node for the interaction between TbPTP1 and TbPIP39. Within 30 min of the initiation of differentiation, TbPIP39 relocates to glycosomes, whereas TbPTP1 disperses to the cytosol. Overall, the study identifies a “stumpy regulatory nexus” (STuRN) that coordinates the molecular components of life cycle signaling and glycosomal development during transmission of Trypanosoma brucei.
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Matange N. Deorphanizing NUDIX hydrolases from Trypanosoma: tantalizing links with metabolic regulation and stress tolerance. Biosci Rep 2019; 39:BSR20191369. [PMID: 31160481 PMCID: PMC6616042 DOI: 10.1042/bsr20191369] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/01/2019] [Accepted: 06/03/2019] [Indexed: 12/15/2022] Open
Abstract
An explosion of sequence information in the genomics era has thrown up thousands of protein sequences without functional assignment. Though our ability to predict function based on sequence alone is improving steadily, we still have a long way to go. Proteins with common evolutionary origins carry telling sequence signatures, which ought to reveal their biological roles. These sequence signatures have allowed us to classify proteins into families with similar structures, and possibly, functions. Yet, evolution is a perpetual tinkerer, and hence, sequence signatures alone have proved inadequate in understanding the physiological activities of proteins. One such enigmatic family of enzymes is the NUDIX ( nu cleoside di phosphate linked to a moiety X ) hydrolase family that has over 80000 members from all branches of the tree of life. Though MutT, the founding member of this family, was identified in 1954, we are only now beginning to understand the diversity of substrates and biological roles that these enzymes demonstrate. In a recent article by Cordeiro et al. in Bioscience Reports [Biosci. Rep. (2019)], two members of this protein family from the human pathogen Trypanosoma brucei were deorphanized as being polyphosphate hydrolases. The authors show that of the five NUDIX hydrolases coded by the T. brucei genomes, TbNH2 and TbNH4, show in vitro hydrolytic activity against inorganic polyphosphate. Through classical biochemistry and immunostaining microscopy, differences in their substrate specificities and sub-cellular localization were revealed. These new data provide a compelling direction to the study of Trypanosome stress biology as well as our understanding of the NUDIX enzyme family.
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Affiliation(s)
- Nishad Matange
- Department of Biology, Indian Institute of Science Education and Research (IISER), Pune, India
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10
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Cordeiro CD, Ahmed MA, Windle B, Docampo R. NUDIX hydrolases with inorganic polyphosphate exo- and endopolyphosphatase activities in the glycosome, cytosol and nucleus of Trypanosoma brucei. Biosci Rep 2019; 39:BSR20190894. [PMID: 31043451 PMCID: PMC6522730 DOI: 10.1042/bsr20190894] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 04/26/2019] [Accepted: 04/30/2019] [Indexed: 12/11/2022] Open
Abstract
Trypanosoma brucei, a protist parasite that causes African trypanosomiasis or sleeping sickness, relies mainly on glycolysis for ATP production when in its mammalian host. Glycolysis occurs within a peroxisome-like organelle named the glycosome. Previous work from our laboratory reported the presence of significant amounts of inorganic polyphosphate (polyP), a polymer of three to hundreds of orthophosphate units, in the glycosomes and nucleoli of T. brucei In this work, we identified and characterized the activity of two Nudix hydrolases (NHs), T. brucei Nudix hydrolase (TbNH) 2 and TbNH4, one located in the glycosomes and the other in the cytosol and nucleus, respectively, which can degrade polyP. We found that TbNH2 is an exopolyphosphatase with higher activity on short chain polyP, while TbNH4 is an endo- and exopolyphosphatase that has similar activity on polyP of various chain sizes. Both enzymes have higher activity at around pH 8.0. We also found that only TbNH2 can dephosphorylate ATP and ADP but with lower affinity than for polyP. Our results suggest that NHs can participate in polyP homeostasis and therefore may help control polyP levels in glycosomes, cytosol and nuclei of T. brucei.
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Affiliation(s)
- Ciro D Cordeiro
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, U.S.A
| | - Michael A Ahmed
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
| | - Brian Windle
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
| | - Roberto Docampo
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
- Department of Cellular Biology, University of Georgia, Athens, GA 30602, U.S.A
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11
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Adhikari A, Biswas S, Mukherjee A, Das S, Adak S. PAS domain-containing phosphoglycerate kinase deficiency in Leishmania major results in increased autophagosome formation and cell death. Biochem J 2019; 476:1303-21. [PMID: 30988012 DOI: 10.1042/BCJ20190041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 04/08/2019] [Accepted: 04/12/2019] [Indexed: 11/17/2022]
Abstract
Per-Arnt-Sim (PAS) domains are structurally conserved and present in numerous proteins throughout all branches of the phylogenetic tree. Although PAS domain-containing proteins are major players for the adaptation to environmental stimuli in both prokaryotic and eukaryotic organisms, these types of proteins are still uncharacterized in the trypanosomatid parasites, Trypanosome and Leishmania In addition, PAS-containing phosphoglycerate kinase (PGK) protein is uncharacterized in the literature. Here, we report a PAS domain-containing PGK (LmPAS-PGK) in the unicellular pathogen Leishmania The modeled structure of N-terminal of this protein exhibits four antiparallel β sheets centrally flanked by α helices, which is similar to the characteristic signature of PAS domain. Activity measurements suggest that acidic pH can directly stimulate PGK activity. Localization studies demonstrate that the protein is highly enriched in the glycosome and its presence can also be seen in the lysosome. Gene knockout, overexpression and complement studies suggest that LmPAS-PGK plays a fundamental role in cell survival through autophagy. Furthermore, the knockout cells display a marked decrease in virulence when host macrophage and BALB/c mice were infected with them. Our work begins to clarify how acidic pH-dependent ATP generation by PGK is likely to function in cellular adaptability of Leishmania.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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13
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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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Cull B, Prado Godinho JL, Fernandes Rodrigues JC, Frank B, Schurigt U, Williams RA, Coombs GH, Mottram JC. Glycosome turnover in Leishmania major is mediated by autophagy. Autophagy 2015; 10:2143-57. [PMID: 25484087 PMCID: PMC4502677 DOI: 10.4161/auto.36438] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Autophagy is a central process behind the cellular remodeling that occurs during differentiation of Leishmania, yet the cargo of the protozoan parasite's autophagosome is unknown. We have identified glycosomes, peroxisome-like organelles that uniquely compartmentalize glycolytic and other metabolic enzymes in Leishmania and other kinetoplastid parasitic protozoa, as autophagosome cargo. It has been proposed that the number of glycosomes and their content change during the Leishmania life cycle as a key adaptation to the different environments encountered. Quantification of RFP-SQL-labeled glycosomes showed that promastigotes of L. major possess ~20 glycosomes per cell, whereas amastigotes contain ~10. Glycosome numbers were significantly greater in promastigotes and amastigotes of autophagy-defective L. major Δatg5 mutants, implicating autophagy in glycosome homeostasis and providing a partial explanation for the previously observed growth and virulence defects of these mutants. Use of GFP-ATG8 to label autophagosomes showed glycosomes to be cargo in ~15% of them; glycosome-containing autophagosomes were trafficked to the lysosome for degradation. The number of autophagosomes increased 10-fold during differentiation, yet the percentage of glycosome-containing autophagosomes remained constant. This indicates that increased turnover of glycosomes was due to an overall increase in autophagy, rather than an upregulation of autophagosomes containing this cargo. Mitophagy of the single mitochondrion was not observed in L. major during normal growth or differentiation; however, mitochondrial remnants resulting from stress-induced fragmentation colocalized with autophagosomes and lysosomes, indicating that autophagy is used to recycle these damaged organelles. These data show that autophagy in Leishmania has a central role not only in maintaining cellular homeostasis and recycling damaged organelles but crucially in the adaptation to environmental change through the turnover of glycosomes.
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Affiliation(s)
- Benjamin Cull
- a Wellcome Trust Center for Molecular Parasitology; Institute of Infection, Immunity and Inflammation; College of Medical, Veterinary and Life Sciences ; University of Glasgow ; Glasgow , UK
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15
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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