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Kannan S, Harel Y, Israel LL, Lellouche E, Varvak A, Tsubery MN, Lellouche JP, Michaeli S. Novel Nanocarrier Platform for Effective Treatment of Visceral Leishmaniasis. Bioconjug Chem 2021; 32:2327-2341. [PMID: 34664934 DOI: 10.1021/acs.bioconjchem.1c00381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Leishmaniasis is among the five parasitic diseases that still require the development of new drugs. Ultrasmall cerium (Ce3/4+) cation-doped maghemite (γ-Fe2O3) nanoparticles (NPs) were tested as a potential drug to treat visceral leishmaniasis, a disease affecting millions of people worldwide. The NPs were engineered for binding a polycationic branched polyethylenimine (PEI) polymer, thereby rupturing the single lysosome of these parasites and enabling entry of the anti-Leishmania drug, pentamidine. Exploiting the known lanthanide cation/complex-based coordinative chemical reactivity enabled the binding of both active agents onto the surface of the NPs. To optimize the fabrication of the cytotoxic NPs, optimization via a DoE (Design of Experiments) process was used to identify the optimal NP with toxicity against the two stages of the parasite, promastigotes, which propagate in the insect, and amastigotes, which infect the mammalian host. The screen identified a single optimized NP (DoE Opt) that was further examined in a mouse model of visceral leishmaniasis. Intravenous injection of the NPs had no adverse effects on the cellular composition or biochemical parameters of the blood, demonstrating no signs of systemic toxicity. The optimized NP was able to eradicate visceral disease caused by Leishmania donovani infection. The study demonstrates the versatile ability of the cerium-doped NPs to bind at least two cytotoxic ligands. This approach could be used for optimizing the binding of different drugs for the treatment of other diseases, including cancer. Since resistance to treatment with nanocarriers was not reported to date, such an approach could potentially overcome drug resistance that emerges when using soluble small molecule drugs.
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Affiliation(s)
- Sriram Kannan
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
- Institute of Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Yifat Harel
- Department of Chemistry Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
- Institute of Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Liron Limor Israel
- Department of Chemistry Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
- Institute of Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Emmanuel Lellouche
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
- Institute of Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Alexander Varvak
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
- Institute of Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Merav Nadav Tsubery
- Department of Chemistry Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Jean-Paul Lellouche
- Department of Chemistry Faculty of Exact Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
- Institute of Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Shulamit Michaeli
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
- Institute of Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat-Gan 5290002, Israel
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Wiser MF. Unique Endomembrane Systems and Virulence in Pathogenic Protozoa. Life (Basel) 2021; 11:life11080822. [PMID: 34440567 PMCID: PMC8401336 DOI: 10.3390/life11080822] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/10/2021] [Accepted: 08/10/2021] [Indexed: 02/06/2023] Open
Abstract
Virulence in pathogenic protozoa is often tied to secretory processes such as the expression of adhesins on parasite surfaces or the secretion of proteases to assisted in tissue invasion and other proteins to avoid the immune system. This review is a broad overview of the endomembrane systems of pathogenic protozoa with a focus on Giardia, Trichomonas, Entamoeba, kinetoplastids, and apicomplexans. The focus is on unique features of these protozoa and how these features relate to virulence. In general, the basic elements of the endocytic and exocytic pathways are present in all protozoa. Some of these elements, especially the endosomal compartments, have been repurposed by the various species and quite often the repurposing is associated with virulence. The Apicomplexa exhibit the most unique endomembrane systems. This includes unique secretory organelles that play a central role in interactions between parasite and host and are involved in the invasion of host cells. Furthermore, as intracellular parasites, the apicomplexans extensively modify their host cells through the secretion of proteins and other material into the host cell. This includes a unique targeting motif for proteins destined for the host cell. Most notable among the apicomplexans is the malaria parasite, which extensively modifies and exports numerous proteins into the host erythrocyte. These modifications of the host erythrocyte include the formation of unique membranes and structures in the host erythrocyte cytoplasm and on the erythrocyte membrane. The transport of parasite proteins to the host erythrocyte involves several unique mechanisms and components, as well as the generation of compartments within the erythrocyte that participate in extraparasite trafficking.
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Affiliation(s)
- Mark F Wiser
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA 70112, USA
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Nano-Leish-IL: A novel iron oxide-based nanocomposite drug platform for effective treatment of cutaneous leishmaniasis. J Control Release 2021; 335:203-215. [PMID: 34019947 DOI: 10.1016/j.jconrel.2021.05.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 04/27/2021] [Accepted: 05/17/2021] [Indexed: 01/03/2023]
Abstract
Kinetoplastids are infamous parasites that include trypanosomes and Leishmania species. Here, we developed an anti-Leishmania nano-drug using ultra-small functional maghemite (γ-Fe2O3) nanoparticles (NPs) that were surface-doped by [CeLn]3/4+ to enable effective binding of the polycationic polyethylenebyimine (PEI) polymer by coordinative chemistry. This resulting nano-drug is cytolytic in-vitro to both Trypanosoma brucei parasites, the causative agent of sleeping sickness, as well as to three Leishmania species. The nano-drug induces the rupture of the single lysosome present in these parasites attributed to the PEI, leading to cytolysis. To evaluate the efficacy of a "cream-based" version of the nano-drug, which was termed "Nano-Leish-IL" for topical treatment of cutaneous leishmaniasis (CL), we developed a rapid screening method utilizing T. brucei parasites involved in social motility and demonstrated that functional NPs arrested the migration of the parasites. This assay presents a surrogate system to rapidly examine the efficacy of "cream-based" drugs in topical preparations against leishmaniasis, and possibly other dermal infectious diseases. The resulting Nano-Leish-IL topical preparation eliminated L. major infection in mice. Thus, this study presents a novel efficient nano-drug targeting the single lysosome of kinetoplastid parasites.
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de Castro Neto AL, da Silveira JF, Mortara RA. Comparative Analysis of Virulence Mechanisms of Trypanosomatids Pathogenic to Humans. Front Cell Infect Microbiol 2021; 11:669079. [PMID: 33937106 PMCID: PMC8085324 DOI: 10.3389/fcimb.2021.669079] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 03/30/2021] [Indexed: 11/23/2022] Open
Abstract
Trypanosoma brucei, Leishmania spp., and T. cruzi are flagellate protozoans of the family Trypanosomatidae and the causative agents of human African trypanosomiasis, leishmaniasis, and Chagas disease, respectively. These diseases affect humans worldwide and exert a significant impact on public health. Over the course of evolution, the parasites associated with these pathologies have developed mechanisms to circumvent the immune response system throughout the infection cycle. In cases of human infection, this function is undertaken by a group of proteins and processes that allow the parasites to propagate and survive during host invasion. In T. brucei, antigenic variation is promoted by variant surface glycoproteins and other proteins involved in evasion from the humoral immune response, which helps the parasite sustain itself in the extracellular milieu during infection. Conversely, Leishmania spp. and T. cruzi possess a more complex infection cycle, with specific intracellular stages. In addition to mechanisms for evading humoral immunity, the pathogens have also developed mechanisms for facilitating their adhesion and incorporation into host cells. In this review, the different immune evasion strategies at cellular and molecular levels developed by these human-pathogenic trypanosomatids have been discussed, with a focus on the key molecules responsible for mediating the invasion and evasion mechanisms and the effects of these molecules on virulence.
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Affiliation(s)
- Artur Leonel de Castro Neto
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - José Franco da Silveira
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Renato Arruda Mortara
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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Maudlin IE, Kelly S, Schwede A, Carrington M. VSG mRNA levels are regulated by the production of functional VSG protein. Mol Biochem Parasitol 2021; 241:111348. [PMID: 33352254 PMCID: PMC7871013 DOI: 10.1016/j.molbiopara.2020.111348] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 02/06/2023]
Abstract
The bloodstream form of Trypanosoma brucei persists in mammalian hosts through a population survival strategy depending on antigenic variation of a cell surface coat composed of the variant surface glycoprotein (VSG). The integrity of the VSG coat is essential and blocking its synthesis results in a cell division cycle arrest just prior to cytokinesis. This observation indicates that VSG levels are monitored and that the cell has mechanisms to respond to a disruption of synthesis. Here, the regulation of VSG mRNA levels has been investigated by first measuring VSG mRNA copy number, and second using ectopic expression of VSG transgenes containing premature termination codons. The findings are that (i) VSG mRNA copy number varies with the identity of the VSG and (ii) a pathway detects synthesis of non-functional VSG protein and results in an increase in VSG mRNA levels.
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Affiliation(s)
- Isabella E Maudlin
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, United Kingdom
| | - Steve Kelly
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, United Kingdom
| | - Angela Schwede
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, United Kingdom.
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, United Kingdom.
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Umaer K, Bangs JD. Late ESCRT machinery mediates the recycling and Rescue of Invariant Surface Glycoprotein 65 in Trypanosoma brucei. Cell Microbiol 2020; 22:e13244. [PMID: 32618070 DOI: 10.1111/cmi.13244] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/25/2020] [Accepted: 06/26/2020] [Indexed: 12/11/2022]
Abstract
The Endosomal Sorting Complex Required for Transport machinery consists of four protein complexes (ESCRT 0-IV) and the post ESCRT ATPase Vps4. ESCRT mediates cargo delivery for lysosomal degradation via formation of multivesicular bodies. Trypanosoma brucei contains orthologues of ESCRT I-III and Vps4. Trypanosomes also have an ubiquitinylated invariant surface glycoprotein (ISG65) that is delivered to the lysosome by ESCRT, however, we previously implicated TbVps4 in rescue and recycling of ISG65. Here we use conditional silencing to investigate the role of TbVps24, a phosphoinositide-binding ESCRT III component, on protein trafficking. TbVps24 localises to the TbRab7+ late endosome, and binds PI(3,5)P2 , the product of the TbFab1 kinase, both of which also localise to late endosomes. TbVps24 silencing is lethal, and negatively affects biosynthetic trafficking of the lysosomal markers p67 and TbCathepsin L. However, the major phenotype of silencing is accelerated degradation and depletion of the surface pool of ISG65. Thus, TbVps24 silencing phenocopies that of TbVps4 in regard to ISG65 trafficking. This presents a paradox since we have previously found that depletion of TbFab1 completely blocks ISG65 turnover. We propose a model in which late ESCRT components operate at two sites, one PI(3,5)P2 -dependent (degradation) and one PI(3,5)P2 -independent (recycling), to regulate ISG65 homeostasis.
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Affiliation(s)
- Khan Umaer
- Department of Microbiology & Immunology, School of Medicine and Biomedical Sciences, University at Buffalo (SUNY), Buffalo, New York, USA
| | - James D Bangs
- Department of Microbiology & Immunology, School of Medicine and Biomedical Sciences, University at Buffalo (SUNY), Buffalo, New York, USA
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Kibria KMK, Ferdous J, Sardar R, Panda A, Gupta D, Mohmmed A, Malhotra P. A genome-wide analysis of coatomer protein (COP) subunits of apicomplexan parasites and their evolutionary relationships. BMC Genomics 2019; 20:98. [PMID: 30704415 PMCID: PMC6357402 DOI: 10.1186/s12864-019-5463-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 01/17/2019] [Indexed: 02/08/2023] Open
Abstract
Background Protein secretion is an essential process in all eukaryotes including organisms belonging to the phylum Apicomplexa, which includes many intracellular parasites. The apicomplexan parasites possess a specialized collection of secretory organelles that release a number of proteins to facilitate the invasion of host cells and some of these proteins also participate in immune evasion. Like in other eukaryotes, these parasites possess a series of membrane-bound compartments, namely the endoplasmic reticulum (ER), the intermediate compartments (IC) or vesicular tubular clusters (VTS) and Golgi complex through which proteins pass in a sequential and vectorial fashion. Two sets of proteins; COPI and COPII are important for directing the sequential transfer of material between the ER and Golgi complex. Results Here, using in silico approaches, we identify the components of COPI and COPII complexes in the genome of apicomplexan organisms. The results showed that the COPI and COPII protein complexes are conserved in most apicomplexan genomes with few exceptions. Diversity among the components of COPI and COPII complexes in apicomplexan is either due to the absence of a subunit or due to the difference in the number of protein domains. For example, the COPI epsilon subunit and COPII sec13 subunit is absent in Babesia bovis, Theileria parva, and Theileria annulata genomes. Phylogenetic and domain analyses for all the proteins of COPI and COPII complexes was performed to predict their evolutionary relationship and functional significance. Conclusions The study thus provides insights into the apicomplexan COPI and COPII coating machinery, which is crucial for parasites secretory network needed for the invasion of host cells. Electronic supplementary material The online version of this article (10.1186/s12864-019-5463-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- K M Kaderi Kibria
- Department of Biotechnology and Genetic Engineering, Mawlana Bhashani Science and Technology University, Santosh, Tangail, 1902, Bangladesh.
| | - Jannatul Ferdous
- Department of Biotechnology and Genetic Engineering, Mawlana Bhashani Science and Technology University, Santosh, Tangail, 1902, Bangladesh
| | - Rahila Sardar
- Translational Bioinformatics Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Ashutosh Panda
- Department of Microbiology, All India Institute of Medical Science, New Delhi, 29, India
| | - Dinesh Gupta
- Translational Bioinformatics Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Asif Mohmmed
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Pawan Malhotra
- Malaria Group, International Centre for Genetic Engineering and Biotechnology, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi, 110067, India
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Bangs JD. Evolution of Antigenic Variation in African Trypanosomes: Variant Surface Glycoprotein Expression, Structure, and Function. Bioessays 2018; 40:e1800181. [PMID: 30370931 PMCID: PMC6441954 DOI: 10.1002/bies.201800181] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 10/04/2018] [Indexed: 12/11/2022]
Abstract
The process of antigenic variation in parasitic African trypanosomes is a remarkable mechanism for outwitting the immune system of the mammalian host, but it requires a delicate balancing act for the monoallelic expression, folding and transport of a single variant surface glycoprotein (VSG). Only one of hundreds of VSG genes is expressed at time, and this from just one of ≈15 dedicated expression sites. By switching expression of VSGs the parasite presents a continuously shifting antigenic facade leading to prolonged chronic infections lasting months to years. The basics of VSG structure and switching have been known for several decades, but recent studies have brought higher resolution to many aspects this process. New VSG structures, in silico modeling of infections, studies of VSG codon usage, and experimental ablation of VSG expression provide insights that inform how this remarkable system may have evolved.
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Affiliation(s)
- James D. Bangs
- Department of Microbiology & Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, 955 Main Street, Buffalo NY 14203,
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Umaer K, Bush PJ, Bangs JD. Rab11 mediates selective recycling and endocytic trafficking in Trypanosoma brucei. Traffic 2018; 19:406-420. [PMID: 29582527 DOI: 10.1111/tra.12565] [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] [Received: 02/06/2018] [Revised: 03/15/2018] [Accepted: 03/15/2018] [Indexed: 01/21/2023]
Abstract
Trypanosoma brucei possesses a streamlined secretory system that guarantees efficient delivery to the cell surface of the critical glycosyl-phosphatidylinositol (GPI)-anchored virulence factors, variant surface glycoprotein (VSG) and transferrin receptor (TfR). Both are thought to be constitutively endocytosed and returned to the flagellar pocket via TbRab11+ recycling endosomes. We use conditional knockdown with established reporters to investigate the role of TbRab11 in specific endomembrane trafficking pathways in bloodstream trypanosomes. TbRab11 is essential. Ablation has a modest negative effect on general endocytosis, but does not affect turnover, steady state levels or surface localization of TfR. Nor are biosynthetic delivery to the cell surface and recycling of VSG affected. TbRab11 depletion also causes increased shedding of VSG into the media by formation of nanotubes and extracellular vesicles. In contrast to GPI-anchored cargo, TbRab11 depletion reduces recycling of the transmembrane invariant surface protein, ISG65, leading to increased lysosomal turnover. Thus, TbRab11 plays a critical role in recycling of transmembrane, but not GPI-anchored surface proteins. We proposed a two-step model for VSG turnover involving release of VSG-containing vesicles followed by GPI hydrolysis. Collectively, our results indicate a critical role of TbRab11 in the homeostatic maintenance of the secretory/endocytic system of bloodstream T. brucei.
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Affiliation(s)
- Khan Umaer
- Department of Microbiology & Immunology, School of Medicine and Biomedical Sciences, University at Buffalo (SUNY), Buffalo, New York
| | - Peter J Bush
- South Campus Instrument Center, School of Dental Medicine, University at Buffalo (SUNY), Buffalo, New York
| | - James D Bangs
- Department of Microbiology & Immunology, School of Medicine and Biomedical Sciences, University at Buffalo (SUNY), Buffalo, New York
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Ooi CP, Smith TK, Gluenz E, Wand NV, Vaughan S, Rudenko G. Blocking variant surface glycoprotein synthesis alters endoplasmic reticulum exit sites/Golgi homeostasis in Trypanosoma brucei. Traffic 2018; 19:391-405. [PMID: 29533496 PMCID: PMC6001540 DOI: 10.1111/tra.12561] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 03/08/2018] [Accepted: 03/08/2018] [Indexed: 12/31/2022]
Abstract
The predominant secretory cargo of bloodstream form Trypanosoma brucei is variant surface glycoprotein (VSG), comprising ~10% total protein and forming a dense protective layer. Blocking VSG translation using Morpholino oligonucleotides triggered a precise pre‐cytokinesis arrest. We investigated the effect of blocking VSG synthesis on the secretory pathway. The number of Golgi decreased, particularly in post‐mitotic cells, from 3.5 ± 0.6 to 2.0 ± 0.04 per cell. Similarly, the number of endoplasmic reticulum exit sites (ERES) in post‐mitotic cells dropped from 3.9 ± 0.6 to 2.7 ± 0.1 eight hours after blocking VSG synthesis. The secretory pathway was still functional in these stalled cells, as monitored using Cathepsin L. Rates of phospholipid and glycosylphosphatidylinositol‐anchor biosynthesis remained relatively unaffected, except for the level of sphingomyelin which increased. However, both endoplasmic reticulum and Golgi morphology became distorted, with the Golgi cisternae becoming significantly dilated, particularly at the trans‐face. Membrane accumulation in these structures is possibly caused by reduced budding of nascent vesicles due to the drastic reduction in the total amount of secretory cargo, that is, VSG. These data argue that the total flux of secretory cargo impacts upon the biogenesis and maintenance of secretory structures and organelles in T. brucei, including the ERES and Golgi.
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Affiliation(s)
- Cher-Pheng Ooi
- Department of Life Sciences, Imperial College London, London, UK
| | - Terry K Smith
- BSRC, School of Biology, University of St. Andrews, St. Andrews, UK
| | - Eva Gluenz
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | | | - Sue Vaughan
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Gloria Rudenko
- Department of Life Sciences, Imperial College London, London, UK
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Guedes RLM, Rodrigues CMF, Coatnoan N, Cosson A, Cadioli FA, Garcia HA, Gerber AL, Machado RZ, Minoprio PMC, Teixeira MMG, de Vasconcelos ATR. A comparative in silico linear B-cell epitope prediction and characterization for South American and African Trypanosoma vivax strains. Genomics 2018; 111:407-417. [PMID: 29499243 DOI: 10.1016/j.ygeno.2018.02.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 02/23/2018] [Accepted: 02/26/2018] [Indexed: 12/11/2022]
Abstract
Trypanosoma vivax is a parasite widespread across Africa and South America. Immunological methods using recombinant antigens have been developed aiming at specific and sensitive detection of infections caused by T. vivax. Here, we sequenced for the first time the transcriptome of a virulent T. vivax strain (Lins), isolated from an outbreak of severe disease in South America (Brazil) and performed a computational integrated analysis of genome, transcriptome and in silico predictions to identify and characterize putative linear B-cell epitopes from African and South American T. vivax. A total of 2278, 3936 and 4062 linear B-cell epitopes were respectively characterized for the transcriptomes of T. vivax LIEM-176 (Venezuela), T. vivax IL1392 (Nigeria) and T. vivax Lins (Brazil) and 4684 for the genome of T. vivax Y486 (Nigeria). The results presented are a valuable theoretical source that may pave the way for highly sensitive and specific diagnostic tools.
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Affiliation(s)
- Rafael Lucas Muniz Guedes
- Laboratório Nacional de Computação Científica (LNCC), Av. Getúlio Vargas, 333, Petrópolis, RJ, Brazil; Grupo Hermes Pardini, Setor de Pesquisa e Desenvolvimento, Vespasiano, MG, Brazil.
| | | | - Nicolas Coatnoan
- Trypanosomatids Infectious Processes Laboratory, Department of Infection and Epidemiology, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris, France
| | - Alain Cosson
- Trypanosomatids Infectious Processes Laboratory, Department of Infection and Epidemiology, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris, France
| | - Fabiano Antonio Cadioli
- Departamento Clínica, Cirurgia e Reprodução Animal, Faculdade de Odontologia e Curso de Medicina Veterinária, Universidade Estadual Paulista - UNESP, Araçatuba, SP, Brazil
| | - Herakles Antonio Garcia
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP 05508-900, Brazil
| | - Alexandra Lehmkuhl Gerber
- Laboratório Nacional de Computação Científica (LNCC), Av. Getúlio Vargas, 333, Petrópolis, RJ, Brazil
| | - Rosangela Zacarias Machado
- Laboratório de Immnoparasitologia, Faculdade de Ciências Agrárias e Veterinárias (FCAV), Universidade Estadual Paulista (UNESP), Campus Jaboticabal, Jaboticabal, SP, Brazil
| | - Paola Marcella Camargo Minoprio
- Trypanosomatids Infectious Processes Laboratory, Department of Infection and Epidemiology, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris, France
| | - Marta Maria Geraldes Teixeira
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP 05508-900, Brazil
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Mucci J, Lantos AB, Buscaglia CA, Leguizamón MS, Campetella O. The Trypanosoma cruzi Surface, a Nanoscale Patchwork Quilt. Trends Parasitol 2016; 33:102-112. [PMID: 27843019 DOI: 10.1016/j.pt.2016.10.004] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 10/11/2016] [Accepted: 10/17/2016] [Indexed: 12/16/2022]
Abstract
The Trypanosoma cruzi trypomastigote membrane provides a major protective role against mammalian host-derived defense mechanisms while allowing the parasite to interact with different cell types and trigger pathogenesis. This surface has been historically appreciated as a rather unstructured 'coat', mainly consisting of a continuous layer of glycolipids and heavily O-glycosylated mucins, occasionally intercalated with different developmentally regulated molecules displaying adhesive and/or enzymatic properties. Recent findings, however, indicate that the trypomastigote membrane is made up of multiple, densely packed and discrete 10-150nm lipid-driven domains bearing different protein composition; hence resembling a highly organized 'patchwork quilt' design. Here, we discuss different aspects underlying the biogenesis, assembly, and dynamics of this cutting-edge fashion outfit, as well as its functional implications.
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Affiliation(s)
- Juan Mucci
- Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), B1650HMP San Martín, Buenos Aires, Argentina
| | - Andrés B Lantos
- Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), B1650HMP San Martín, Buenos Aires, Argentina
| | - Carlos A Buscaglia
- Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), B1650HMP San Martín, Buenos Aires, Argentina
| | - María Susana Leguizamón
- Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), B1650HMP San Martín, Buenos Aires, Argentina
| | - Oscar Campetella
- Instituto de Investigaciones Biotecnológicas - Instituto Tecnológico de Chascomús (IIB-INTECH), Universidad Nacional de San Martín (UNSAM) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), B1650HMP San Martín, Buenos Aires, Argentina.
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13
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Hu H, Gourguechon S, Wang CC, Li Z. The G1 Cyclin-dependent Kinase CRK1 in Trypanosoma brucei Regulates Anterograde Protein Transport by Phosphorylating the COPII Subunit Sec31. J Biol Chem 2016; 291:15527-39. [PMID: 27252375 PMCID: PMC4957039 DOI: 10.1074/jbc.m116.715185] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Indexed: 01/02/2023] Open
Abstract
Transport of secretory proteins from the endoplasmic reticulum to the Golgi is mediated by the coat protein II (COPII) complex comprising a Sec23-Sec24 heterodimer and a Sec13-Sec31 heterotetramer. The mechanisms underlying COPII-mediated protein trafficking have been well defined, but the extent of regulation of this secretory machinery by cellular signaling pathways remains poorly understood. Here, we report that CRK1, a G1 cyclin-dependent kinase in Trypanosoma brucei, regulates anterograde protein trafficking by phosphorylating Sec31. Depletion of CRK1 abolished anterograde transport of the secretory protein and disrupted the localization of multiple Golgi proteins, reminiscent of Sec31 depletion. CRK1 phosphorylates Sec31 at multiple serine/threonine sites, and mutation of these phosphosites to alanine recapitulates the protein trafficking defects caused by Sec31 depletion. Mutation of these CRK1 phosphosites to aspartate restored Sec31 function. Taken together, these results uncover a novel function of CRK1 in anterograde protein trafficking and elucidate the mechanistic role of CRK1 in protein trafficking through regulation of the COPII subunit Sec31.
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Affiliation(s)
- Huiqing Hu
- From the Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030 and
| | - Stéphane Gourguechon
- the Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, California 94158
| | - Ching C Wang
- the Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, California 94158
| | - Ziyin Li
- From the Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030 and
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Morriswood B. Form, Fabric, and Function of a Flagellum-Associated Cytoskeletal Structure. Cells 2015; 4:726-47. [PMID: 26540076 PMCID: PMC4695855 DOI: 10.3390/cells4040726] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/27/2015] [Accepted: 10/29/2015] [Indexed: 01/01/2023] Open
Abstract
Trypanosoma brucei is a uniflagellated protist and the causative agent of African trypanosomiasis, a neglected tropical disease. The single flagellum of T. brucei is essential to a number of cellular processes such as motility, and has been a longstanding focus of scientific enquiry. A number of cytoskeletal structures are associated with the flagellum in T. brucei, and one such structure—a multiprotein complex containing the repeat motif protein TbMORN1—is the focus of this review. The TbMORN1-containing complex, which was discovered less than ten years ago, is essential for the viability of the mammalian-infective form of T. brucei. The complex has an unusual asymmetric morphology, and is coiled around the flagellum to form a hook shape. Proteomic analysis using the proximity-dependent biotin identification (BioID) technique has elucidated a number of its components. Recent work has uncovered a role for TbMORN1 in facilitating protein entry into the cell, thus providing a link between the cytoskeleton and the endomembrane system. This review summarises the extant data on the complex, highlights the outstanding questions for future enquiry, and provides speculation as to its possible role in a size-exclusion mechanism for regulating protein entry. The review additionally clarifies the nomenclature associated with this topic, and proposes the adoption of the term “hook complex” to replace the former name “bilobe” to describe the complex.
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Affiliation(s)
- Brooke Morriswood
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, Am Hubland, D-97074, Würzburg, Germany.
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15
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Matthews KR. 25 years of African trypanosome research: From description to molecular dissection and new drug discovery. Mol Biochem Parasitol 2015; 200:30-40. [PMID: 25736427 PMCID: PMC4509711 DOI: 10.1016/j.molbiopara.2015.01.006] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/09/2015] [Accepted: 01/13/2015] [Indexed: 01/27/2023]
Abstract
The Molecular Parasitology conference was first held at the Marine Biological laboratory, Woods Hole, USA 25 years ago. Since that first meeting, the conference has evolved and expanded but has remained the showcase for the latest research developments in molecular parasitology. In this perspective, I reflect on the scientific discoveries focussed on African trypanosomes (Trypanosoma brucei spp.) that have occurred since the inaugural MPM meeting and discuss the current and future status of research on these parasites.
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Affiliation(s)
- Keith R Matthews
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, UK.
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16
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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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17
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Niyogi S, Mucci J, Campetella O, Docampo R. Rab11 regulates trafficking of trans-sialidase to the plasma membrane through the contractile vacuole complex of Trypanosoma cruzi. PLoS Pathog 2014; 10:e1004224. [PMID: 24968013 PMCID: PMC4072791 DOI: 10.1371/journal.ppat.1004224] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 05/19/2014] [Indexed: 01/09/2023] Open
Abstract
Trypanosoma cruzi is the etiologic agent of Chagas disease. Although this is not a free-living organism it has conserved a contractile vacuole complex (CVC) to regulate its osmolarity. This obligate intracellular pathogen is, in addition, dependent on surface proteins to invade its hosts. Here we used a combination of genetic and biochemical approaches to delineate the contribution of the CVC to the traffic of glycosylphosphatidylinositol (GPI)-anchored proteins to the plasma membrane of the parasite and promote host invasion. While T. cruzi Rab11 (GFP-TcRab11) localized to the CVC, a dominant negative (DN) mutant tagged with GFP (GFP-TcRab11DN) localized to the cytosol, and epimastigotes expressing this mutant were less responsive to hyposmotic and hyperosmotic stress. Mutant parasites were still able to differentiate into metacyclic forms and infect host cells. GPI-anchored trans-sialidase (TcTS), mucins of the 60-200 KDa family, and trypomastigote small surface antigen (TcTSSA II) co-localized with GFP-TcRab11 to the CVC during transformation of intracellular amastigotes into trypomastigotes. Mucins of the gp35/50 family also co-localized with the CVC during metacyclogenesis. Parasites expressing GFP-TcRab11DN prevented TcTS, but not other membrane proteins, from reaching the plasma membrane, and were less infective as compared to wild type cells. Incubation of these mutants in the presence of exogenous recombinant active, but not inactive, TcTS, and a sialic acid donor, before infecting host cells, partially rescued infectivity of trypomastigotes. Taking together these results reveal roles of TcRab11 in osmoregulation and trafficking of trans-sialidase to the plasma membrane, the role of trans-sialidase in promoting infection, and a novel unconventional mechanism of GPI-anchored protein secretion.
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Affiliation(s)
- Sayantanee Niyogi
- Department of Cellular Biology and Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Juan Mucci
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín/Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Oscar Campetella
- Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín/Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Roberto Docampo
- Department of Cellular Biology and Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, United States of America
- * E-mail:
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Manna PT, Boehm C, Leung KF, Natesan SK, Field MC. Life and times: synthesis, trafficking, and evolution of VSG. Trends Parasitol 2014; 30:251-8. [PMID: 24731931 PMCID: PMC4007029 DOI: 10.1016/j.pt.2014.03.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 03/14/2014] [Accepted: 03/14/2014] [Indexed: 11/30/2022]
Abstract
Evasion of the acquired immune response in African trypanosomes is principally mediated by antigenic variation, the sequential expression of distinct variant surface glycoproteins (VSGs) at extremely high density on the cell surface. Sequence diversity between VSGs facilitates escape of a subpopulation of trypanosomes from antibody-mediated killing. Significant advances have increased understanding of the mechanisms underpinning synthesis and maintenance of the VSG coat. In this review, we discuss the biosynthesis, trafficking, and turnover of VSG, emphasising those unusual mechanisms that act to maintain coat integrity and to protect against immunological attack. We also highlight new findings that suggest the presence of unique or highly divergent proteins that may offer therapeutic opportunities, as well as considering aspects of VSG biology that remain to be fully explored.
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Affiliation(s)
- Paul T Manna
- Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee, DD1 5EH, UK
| | - Cordula Boehm
- Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee, DD1 5EH, UK
| | - Ka Fai Leung
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Senthil Kumar Natesan
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Mark C Field
- Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee, DD1 5EH, UK.
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Sealey-Cardona M, Schmidt K, Demmel L, Hirschmugl T, Gesell T, Dong G, Warren G. Sec16 Determines the Size and Functioning of the Golgi in the Protist Parasite,Trypanosoma brucei. Traffic 2014; 15:613-29. [DOI: 10.1111/tra.12170] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 03/05/2014] [Accepted: 03/10/2014] [Indexed: 12/11/2022]
Affiliation(s)
- Marco Sealey-Cardona
- Max F. Perutz Laboratories; University of Vienna and Medical University of Vienna; Dr. Bohr-Gasse 9/3 1030, Vienna Austria
| | - Katy Schmidt
- Max F. Perutz Laboratories; University of Vienna and Medical University of Vienna; Dr. Bohr-Gasse 9/3 1030, Vienna Austria
| | - Lars Demmel
- Max F. Perutz Laboratories; University of Vienna and Medical University of Vienna; Dr. Bohr-Gasse 9/3 1030, Vienna Austria
| | - Tatjana Hirschmugl
- Research Center for Molecular Medicine of the Austrian Academy of Sciences (CeMM); 1090, Vienna Austria
| | - Tanja Gesell
- Department of Structural and Computational Biology, Max F. Perutz Laboratories; University of Vienna; Dr. Bohr-Gasse 9 1030, Vienna Austria
| | - Gang Dong
- Department of Medical Biochemistry; Medical University of Vienna; Dr. Bohr-Gasse 9/3 1030 Vienna Austria
| | - Graham Warren
- Max F. Perutz Laboratories; University of Vienna and Medical University of Vienna; Dr. Bohr-Gasse 9/3 1030, Vienna Austria
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Gallet C, Demonchy R, Koppel C, Grellier P, Kohl L. A Protein Phosphatase 1 involved in correct nucleus positioning in trypanosomes. Mol Biochem Parasitol 2013; 192:49-54. [DOI: 10.1016/j.molbiopara.2013.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 11/22/2013] [Accepted: 11/24/2013] [Indexed: 11/16/2022]
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21
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Lott K, Li J, Fisk JC, Wang H, Aletta JM, Qu J, Read LK. Global proteomic analysis in trypanosomes reveals unique proteins and conserved cellular processes impacted by arginine methylation. J Proteomics 2013; 91:210-25. [PMID: 23872088 PMCID: PMC3935770 DOI: 10.1016/j.jprot.2013.07.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 06/26/2013] [Accepted: 07/07/2013] [Indexed: 12/14/2022]
Abstract
Arginine methylation is a common posttranslational modification with reported functions in transcription, RNA processing and translation, and DNA repair. Trypanosomes encode five protein arginine methyltransferases, suggesting that arginine methylation exerts widespread impacts on the biology of these organisms. Here, we performed a global proteomic analysis of Trypanosoma brucei to identify arginine methylated proteins and their sites of modification. Using an approach entailing two-dimensional chromatographic separation and alternating electron transfer dissociation and collision induced dissociation, we identified 1332 methylarginines in 676 proteins. The resulting data set represents the largest compilation of arginine methylated proteins in any organism to date. Functional classification revealed numerous arginine methylated proteins involved in flagellar function, RNA metabolism, DNA replication and repair, and intracellular protein trafficking. Thus, arginine methylation has the potential to impact aspects of T. brucei gene expression, cell biology, and pathogenesis. Interestingly, pathways with known methylated proteins in higher eukaryotes were identified in this study, but often different components of the pathway were methylated in trypanosomes. Methylarginines were often identified in glycine rich contexts, although exceptions to this rule were detected. Collectively, these data inform on a multitude of aspects of trypanosome biology and serve as a guide for the identification of homologous arginine methylated proteins in higher eukaryotes. BIOLOGICAL SIGNIFICANCE T. brucei is a protozoan parasite that causes lethal African sleeping sickness in humans and nagana in livestock, thereby imposing a significant medical and economic burden on sub-Saharan Africa. The parasite encounters very different environments as it cycles between mammalian and insect hosts, and must exert cellular responses to these varying milieus. One mechanism by which all cells respond to changing environments is through posttranslational modification of proteins. Arginine methylation is one such modification that can dramatically impact protein-protein and protein-nucleic acid interactions and subcellular localization of proteins. To define the breadth of arginine methylation in trypanosomes and identify target proteins, we performed a global proteomic analysis of arginine methylated proteins in insect stage T. brucei. We identified 1332 methylarginines in 676 proteins, generating the largest compilation of methylarginine containing proteins in any organism to date. Numerous arginine methylated proteins function in RNA and DNA related processes, suggesting this modification can impact T. brucei genome integrity and gene regulation at numerous points. Other processes that appear to be strongly influenced by arginine methylation are intracellular protein trafficking, signaling, protein folding and degradation, and flagellar function. The widespread nature of arginine methylation in trypanosomes highlights its potential to greatly affect parasite biology and pathogenesis.
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Affiliation(s)
- Kaylen Lott
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, New York, United States of America
| | - Jun Li
- Department of Pharmaceutical Sciences, University at Buffalo, Buffalo, NY, United States of America
| | - John C. Fisk
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, New York, United States of America
| | - Hao Wang
- Department of Pharmaceutical Sciences, University at Buffalo, Buffalo, NY, United States of America
| | - John M. Aletta
- CH3 BioSystems, New York State Center of Excellence in Bioinformatics and Life Sciences, Buffalo, NY, United States of America
| | - Jun Qu
- Department of Pharmaceutical Sciences, University at Buffalo, Buffalo, NY, United States of America
| | - Laurie K. Read
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, New York, United States of America
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Silverman JS, Muratore KA, Bangs JD. Characterization of the late endosomal ESCRT machinery in Trypanosoma brucei. Traffic 2013; 14:1078-90. [PMID: 23905922 DOI: 10.1111/tra.12094] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 07/24/2013] [Accepted: 07/26/2013] [Indexed: 12/31/2022]
Abstract
The multivesicular body (MVB) is a specialized Rab7+ late endosome (LE) containing multiple intralumenal vesicles that function in targeting ubiquitinylated cell surface proteins to the lysosome for degradation. African trypanosomes lack a morphologically well-defined MVB, but contain orthologs of the ESCRT (Endosomal Sorting Complex Required for Transport) machinery that mediates MVB formation. We investigate the role of TbVps23, an early ESCRT component, and TbVps4, the terminal ESCRT ATPase, in lysosomal trafficking in bloodstream form trypanosomes. Both localize to the TbRab7+ LE and RNAi silencing of each rapidly blocks growth. TbVps4 silencing results in approximately threefold accumulation of TbVps23 at the LE, consistent with blocking terminal ESCRT disassembly. Trafficking of endocytic and biosynthetic cargo, but not default lysosomal reporters, is also negatively affected. Others reported that TbVps23 mediates ubiquitin-dependent lysosomal degradation of invariant surface glycoproteins (ISG65) (Leung et al., Traffic 2008;9:1698-1716). In contrast, we find that TbVps23 ablation does not affect ISG65 turnover, while TbVps4 silencing markedly enhances lysosomal degradation. We propose several models to accommodate these results, including that the ESCRT machinery actually retrieves ISG65 from the LE to earlier endocytic compartments, and in its absence ISG65 traffics more efficiently to the lysosome. Overall, these results confirm that the ESCRT machinery is essential in Trypanosoma brucei and plays important and novel role(s) in LE function in trypanosomes.
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Affiliation(s)
- Jason S Silverman
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo (SUNY), 138 Farber Hall, 3435 Main Street, Buffalo, NY, 14214, USA; Current address: Monsanto Company, Mailstop LS2A, 800 N Lindbergh Blvd, Saint Louis, MO 63167, USA
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Intracellular trafficking and glycobiology of TbPDI2, a stage-specific protein disulfide isomerase in Trypanosoma brucei. EUKARYOTIC CELL 2012; 12:132-41. [PMID: 23159520 DOI: 10.1128/ec.00293-12] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Trypanosoma brucei protein disulfide isomerase 2 (TbPDI2) is a bloodstream stage-specific lumenal endoplasmic reticulum (ER) glycoprotein. ER localization is dependent on the TbPDI2 C-terminal tetrapeptide (KQDL) and is mediated by TbERD2, an orthologue of the yeast ER retrieval receptor. Consistent with this function, TbERD2 localizes prominently to ER exit sites, and RNA interference (RNAi) knockdown results in specific secretion of a surrogate ER retention reporter, BiPN:KQDL. TbPDI2 is highly N-glycosylated and is reactive with tomato lectin, suggesting the presence of poly-N-acetyllactosamine modifications, which are common on lyso/endosomal proteins in trypanosomes but are inconsistent with ER localization. However, TbPDI2 is reactive with tomato lectin immediately following biosynthesis-far too rapidly for transport to the Golgi compartment, the site of poly-N-acetyllactosamine addition. TbPDI2 also fails to react with Erythrina cristagalli lectin, confirming the absence of terminal N-acetyllactosamine units. We propose that tomato lectin binds the Manβ1-4GlcNAcβ1-4GlcNAc trisaccharide core of paucimannose glycans on both newly synthesized and mature TbPDI2. Consistent with this proposal, α-mannosidase treatment renders oligomannose N-glycans on the T. brucei cathepsin L orthologue TbCatL reactive with tomato lectin. These findings resolve contradictory evidence on the location and glycobiology of TbPDI2 and provide a cautionary note on the use of tomato lectin as a poly-N-acetyllactosamine-specific reagent.
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