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Berhe H, Kumar Cinthakunta Sridhar M, Zerihun M, Qvit N. The Potential Use of Peptides in the Fight against Chagas Disease and Leishmaniasis. Pharmaceutics 2024; 16:227. [PMID: 38399281 PMCID: PMC10892537 DOI: 10.3390/pharmaceutics16020227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 12/28/2023] [Accepted: 01/30/2024] [Indexed: 02/25/2024] Open
Abstract
Chagas disease and leishmaniasis are both neglected tropical diseases that affect millions of people around the world. Leishmaniasis is currently the second most widespread vector-borne parasitic disease after malaria. The World Health Organization records approximately 0.7-1 million newly diagnosed leishmaniasis cases each year, resulting in approximately 20,000-30,000 deaths. Also, 25 million people worldwide are at risk of Chagas disease and an estimated 6 million people are infected with Trypanosoma cruzi. Pentavalent antimonials, amphotericin B, miltefosine, paromomycin, and pentamidine are currently used to treat leishmaniasis. Also, nifurtimox and benznidazole are two drugs currently used to treat Chagas disease. These drugs are associated with toxicity problems such as nephrotoxicity and cardiotoxicity, in addition to resistance problems. As a result, the discovery of novel therapeutic agents has emerged as a top priority and a promising alternative. Overall, there is a need for new and effective treatments for Chagas disease and leishmaniasis, as the current drugs have significant limitations. Peptide-based drugs are attractive due to their high selectiveness, effectiveness, low toxicity, and ease of production. This paper reviews the potential use of peptides in the treatment of Chagas disease and leishmaniasis. Several studies have demonstrated that peptides are effective against Chagas disease and leishmaniasis, suggesting their use in drug therapy for these diseases. Overall, peptides have the potential to be effective therapeutic agents against Chagas disease and leishmaniasis, but more research is needed to fully investigate their potential.
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Affiliation(s)
| | | | | | - Nir Qvit
- The Azrieli Faculty of Medicine in the Galilee, Bar-Ilan University, Safed 1311502, Israel; (H.B.); (M.K.C.S.); (M.Z.)
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Al-Khalaifah HS. Major Molecular Factors Related to Leishmania Pathogenicity. Front Immunol 2022; 13:847797. [PMID: 35769465 PMCID: PMC9236557 DOI: 10.3389/fimmu.2022.847797] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 04/05/2022] [Indexed: 11/13/2022] Open
Abstract
Leishmaniasis is a major health problem with 600k - 1M new cases worldwide and 1 billion at risk. It involves a wide range of clinical forms ranging from self-healing cutaneous lesions to systemic diseases that are fatal if not treated, depending on the species of Leishmania. Leishmania sp. are digenetic parasites that have two different morphological stages. Leishmania parasites possess a number of invasive/evasive and pathoantigenic determinants that seem to have critical roles in Leishmania infection of macrophages which leads to successful intracellular parasitism in the parasitophorous vacuoles. These determinants are traditionally known as “virulence factors”, and are considered to be good targets for developing specific inhibitors to attenuate virulence of Leishmania by gene deletions or modifications, thus causing infective, but non-pathogenic mutants for vaccination. Pathway of biosynthesis is critical for keeping the parasite viable and is important for drug designing against these parasites. These drugs are aimed to target enzymes that control these pathways. Accordingly, maintaining low level of parasitic infection and in some cases as a weapon to eradicate infection completely. The current paper focuses on several virulence factors as determinants of Leishmania pathogenicity, as well as the metabolites produced by Leishmania to secure its survival in the host.
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Dong G, Wagner V, Minguez-Menendez A, Fernandez-Prada C, Olivier M. Extracellular vesicles and leishmaniasis: Current knowledge and promising avenues for future development. Mol Immunol 2021; 135:73-83. [PMID: 33873096 DOI: 10.1016/j.molimm.2021.04.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/23/2021] [Accepted: 04/01/2021] [Indexed: 02/09/2023]
Abstract
Extracellular vesicles (EVs) are small, membrane-bound "delivery trucks" that are present in the extracellular environment, including biological fluids. EVs are capable of inducing changes in the physiological status of neighboring cells through the transfer of key macromolecules, and are thought to play a role in a number of pathological processes. Leishmaniasis, caused by the protozoan parasite Leishmania, is an important example. The biology of Leishmania EVs has been studied in detail, and findings point to their role in exacerbation of disease and potential involvement in the perpetuation of drug resistance. Furthermore, the use of EVs for development of vaccines has been explored, as well as their potential use in a number of fields as biomarkers of disease and drug resistance. Here we discuss the latest findings on EVs, with a particular focus on Leishmania, as well as potential avenues for their future development and clinical applications.
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Affiliation(s)
- George Dong
- Infectious Diseases and Immunology in Global Health Program (IDIGH), The Research Institute of the McGill University Health Centre, Montréal, QC, Canada
| | - Victoria Wagner
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, QC, Canada; The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculty of Veterinary Medicine, Université de Montréal, QC, Canada
| | | | - Christopher Fernandez-Prada
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Université de Montréal, QC, Canada; The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculty of Veterinary Medicine, Université de Montréal, QC, Canada.
| | - Martin Olivier
- Infectious Diseases and Immunology in Global Health Program (IDIGH), The Research Institute of the McGill University Health Centre, Montréal, QC, Canada; Departments of Medicine, Microbiology and Immunology, Faculty of Medicine, McGill University, Montréal, QC, Canada.
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Desnoyer N, Howard G, Jong E, Palanivelu R. AtPIG-S, a predicted Glycosylphosphatidylinositol Transamidase subunit, is critical for pollen tube growth in Arabidopsis. BMC PLANT BIOLOGY 2020; 20:380. [PMID: 32811442 PMCID: PMC7437025 DOI: 10.1186/s12870-020-02587-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 08/03/2020] [Indexed: 05/23/2023]
Abstract
BACKGROUND Glycosylphosphatidylinositol (GPI) addition is one of the several post-translational modifications to proteins that increase their affinity for membranes. In eukaryotes, the GPI transamidase complex (GPI-T) catalyzes the attachment of pre-assembled GPI anchors to GPI-anchored proteins (GAPs) through a transamidation reaction. A mutation in AtGPI8 (gpi8-2), the putative catalytic subunit of GPI-T in Arabidopsis, is transmitted normally through the female gametophyte (FG), indicating the FG tolerates loss of GPI transamidation. In contrast, gpi8-2 almost completely abolishes male gametophyte (MG) function. Still, the unexpected finding that gpi8-2 FGs function normally requires further investigation. Additionally, specific developmental defects in the MG caused by loss of GPI transamidation remain poorly characterized. RESULTS Here we investigated the effect of loss of AtPIG-S, another GPI-T subunit, in both gametophytes. Like gpi8-2, we showed that a mutation in AtPIG-S (pigs-1) disrupted synergid localization of LORELEI (LRE), a putative GAP critical for pollen tube reception by the FG. Still, pigs-1 is transmitted normally through the FG. Conversely, pigs-1 severely impaired male gametophyte (MG) function during pollen tube emergence and growth in the pistil. A pPIGS:GFP-PIGS transgene complemented these MG defects and enabled generation of pigs-1/pigs-1 seedlings. However, the pPIGS:GFP-PIGS transgene seemingly failed to rescue the function of AtPIG-S in the sporophyte, as pigs-1/pigs-1, pPIGS:GFP-PIGS seedlings died soon after germination. CONCLUSIONS Characterization of pigs-1 provided further evidence that the FG tolerates loss of GPI transamidation more than the MG and that the MG compared to the FG may be a better haploid system to study the role of GPI-anchoring. Pigs-1 pollen develops normally and thus represent a tool in which GPI anchor biosynthesis and transamidation of GAPs have been uncoupled, offering a potential way to study free GPI in plant development. While previously reported male fertility defects of GPI biosynthesis mutants could have been due either to loss of GPI or GAPs lacking the GPI anchor, our results clarified that the loss of mature GAPs underlie male fertility defects of GPI-deficient pollen grains, as pigs-1 is defective only in the downstream transamidation step.
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Affiliation(s)
- Nicholas Desnoyer
- School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
- Present Address: Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, CH-8008, Zurich, Switzerland
| | - Gregory Howard
- School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Emma Jong
- School of Plant Sciences, University of Arizona, Tucson, AZ, 85721, USA
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Mule SN, Saad JS, Fernandes LR, Stolf BS, Cortez M, Palmisano G. Protein glycosylation inLeishmaniaspp. Mol Omics 2020; 16:407-424. [DOI: 10.1039/d0mo00043d] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Protein glycosylation is a co- and post-translational modification that, inLeishmaniaparasites, plays key roles in vector–parasite–vertebrate host interaction.
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Affiliation(s)
- Simon Ngao Mule
- GlycoProteomics Laboratory
- Department of Parasitology
- Institute of Biomedical Sciences
- University of Sao Paulo
- Sao Paulo - 05508-000
| | - Joyce Silva Saad
- GlycoProteomics Laboratory
- Department of Parasitology
- Institute of Biomedical Sciences
- University of Sao Paulo
- Sao Paulo - 05508-000
| | - Livia Rosa Fernandes
- GlycoProteomics Laboratory
- Department of Parasitology
- Institute of Biomedical Sciences
- University of Sao Paulo
- Sao Paulo - 05508-000
| | - Beatriz S. Stolf
- Department of Parasitology
- Institute of Biomedical Sciences
- University of Sao Paulo
- Sao Paulo
- Brazil
| | - Mauro Cortez
- Department of Parasitology
- Institute of Biomedical Sciences
- University of Sao Paulo
- Sao Paulo
- Brazil
| | - Giuseppe Palmisano
- GlycoProteomics Laboratory
- Department of Parasitology
- Institute of Biomedical Sciences
- University of Sao Paulo
- Sao Paulo - 05508-000
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Morotti ALM, Martins-Teixeira MB, Carvalho I. Protozoan Parasites Glycosylphosphatidylinositol Anchors: Structures, Functions and Trends for Drug Discovery. Curr Med Chem 2019; 26:4301-4322. [PMID: 28748758 DOI: 10.2174/0929867324666170727110801] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/12/2017] [Accepted: 07/12/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND Glycosylphosphatidylinositol (GPI) anchors are molecules located on cell membranes of all eukaryotic organisms. Proteins, enzymes, and other macromolecules which are anchored by GPIs are essential elements for interaction between cells, and are widely used by protozoan parasites when compared to higher eukaryotes. METHODS More than one hundred references were collected to obtain broad information about mammalian and protozoan parasites' GPI structures, biosynthetic pathways, functions and attempts to use these molecules as drug targets against parasitic diseases. Differences between GPI among species were compared and highlighted. Strategies for drug discovery and development against protozoan GPI anchors were discussed based on what has been reported on literature. RESULTS There are many evidences that GPI anchors are crucial for parasite's survival and interaction with hosts' cells. Despite all GPI anchors contain a conserved glycan core, they present variations regarding structural features and biosynthetic pathways between organisms, which could offer adequate selectivity to validate GPI anchors as drug targets. Discussion was developed with focus on the following parasites: Trypanosoma brucei, Trypanosoma cruzi, Leishmania, Plasmodium falciparum and Toxoplasma gondii, causative agents of tropical neglected diseases. CONCLUSION This review debates the main variances between parasitic and mammalian GPI anchor biosynthesis and structures, as well as clues for strategic development for new anti-parasitic therapies based on GPI anchors.
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Affiliation(s)
- Ana Luísa Malaco Morotti
- School of Pharmaceutical Sciences of Ribeirao Preto - University of Sao Paulo, Sao Paulo, Brazil
| | | | - Ivone Carvalho
- School of Pharmaceutical Sciences of Ribeirao Preto - University of Sao Paulo, Sao Paulo, Brazil
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Abbasnia T, Asoodeh A, Habibi G, Haghparast A. Isolation and purification of glycosylphosphatidylinositols (GPIs) in the schizont stage of Theileria annulata and determination of antibody response to GPI anchors in vaccinated and infected animals. Parasit Vectors 2018; 11:82. [PMID: 29409517 PMCID: PMC5802100 DOI: 10.1186/s13071-018-2651-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 01/16/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tropical theileriosis is widely distributed from North Africa to East Asia. It is a tick-borne disease caused by Theileria annulata, an obligate two-host intracellular protozoan parasite of cattle. Theileria annulata use leukocytes and red blood cells for completion of the life-cycle in mammalian hosts. The stage of Theileria annulata in monocytes and B lymphocytes of cattle is an important step in pathogenicity and diagnosis of the disease. Glycosylphosphatidylinositols (GPIs) are a distinct class of glycolipid structures found in eukaryotic cells and are implicated in several biological functions. GPIs are particularly abundant in protozoan parasites, where they are found as free glycolipids or attached to proteins in the plasma membrane. RESULTS In this study we first isolated and purified schizonts of Theileria annulata from infected leukocytes in Theileria annulata vaccine cell line (S15) by aerolysin-percoll technique. Then, the free GPIs of schizont stage and isolated GPI from cell membrane glycoproteins were purified by high performance liquid chromatography (HPLC) and confirmed by gas chromatography-mass spectrometry (GC-MS). Furthermore, enzyme linked immunosorbent assay (ELISA) on the serum samples obtained from naturally infected, as well as Theileria annulata-vaccinated animals, confirmed a significant (P < 0.01) high level of anti-GPI antibody in their serum. CONCLUSIONS The results presented in this study show, to our knowledge for the first time, the isolation of GPI from the schizont stage of Theileria annulata and demonstrate the presence of anti-GPI antibody in the serum of naturally infected as well as vaccinated animals. This finding is likely to be valuable in studies aimed at the evaluation of chemically structures of GPIs in the schizont stage of Theileria annulata and also for pathogenicity and immunogenicity studies with the aim to develop GPI-based therapies or vaccines.
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Affiliation(s)
- Toktam Abbasnia
- Division of Biotechnology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, P.O. Box: 91775-1793, Mashhad, Iran
| | - Ahmad Asoodeh
- Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Gholamreza Habibi
- Department of Parasite Vaccine Research and Production, Razi Vaccine and Serum Research Institute, Karaj, Iran
| | - Alireza Haghparast
- Division of Biotechnology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, P.O. Box: 91775-1793, Mashhad, Iran. .,Immunology Section, Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran.
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Khan AH, Bayat H, Rajabibazl M, Sabri S, Rahimpour A. Humanizing glycosylation pathways in eukaryotic expression systems. World J Microbiol Biotechnol 2016; 33:4. [DOI: 10.1007/s11274-016-2172-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 11/04/2016] [Indexed: 01/27/2023]
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Atayde VD, Hassani K, da Silva Lira Filho A, Borges AR, Adhikari A, Martel C, Olivier M. Leishmania exosomes and other virulence factors: Impact on innate immune response and macrophage functions. Cell Immunol 2016; 309:7-18. [PMID: 27499212 DOI: 10.1016/j.cellimm.2016.07.013] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/14/2016] [Accepted: 07/25/2016] [Indexed: 12/23/2022]
Abstract
Leishmania parasites are the causative agents of the leishmaniases, a collection of vector-borne diseases that range from simple cutaneous to fatal visceral forms. Employing potent immune modulation mechanisms, Leishmania is able to render the host macrophage inactive and persist inside its phagolysosome. In the last few years, the role of exosomes in Leishmania-host interactions has been increasingly investigated. For instance, it was reported that Leishmania exosome release is augmented following temperature shift, a condition mimicking parasite's entry into its mammalian host. Leishmania exosomes were found to strongly affect macrophage cell signaling and functions, similarly to whole parasites. Importantly, these vesicles were shown to be pro-inflammatory, capable to recruit neutrophils at their inoculation site exacerbating the pathology. In this review, we provide the most recent insights on the role of exosomes and other virulence factors, especially the surface protease GP63, in Leishmania-host interactions, deepening our knowledge on leishmaniasis and paving the way for the development of new therapeutics.
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Affiliation(s)
- Vanessa Diniz Atayde
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada
| | - Kasra Hassani
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada
| | - Alonso da Silva Lira Filho
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada
| | - Andrezza Raposo Borges
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada
| | - Anupam Adhikari
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada
| | - Caroline Martel
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada
| | - Martin Olivier
- Departments of Medicine, Microbiology and Immunology, McGill University, 3775 University Street, Montréal, QC H3A 2B4, Canada; Infectious Diseases and Immunity in Global Heath Program, The Research Institute of the McGill University Health Centre, 1001 Boulevard Décarie, Montréal, QC H4A 3J1, Canada.
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Cabezas Y, Legentil L, Robert-Gangneux F, Daligault F, Belaz S, Nugier-Chauvin C, Tranchimand S, Tellier C, Gangneux JP, Ferrières V. Leishmania cell wall as a potent target for antiparasitic drugs. A focus on the glycoconjugates. Org Biomol Chem 2016; 13:8393-404. [PMID: 26130402 DOI: 10.1039/c5ob00563a] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Although leishmaniasis has been studied for over a century, the fight against cutaneous, mucocutaneous and visceral forms of the disease remains a hot topic. This review refers to the parasitic cell wall and more particularly to the constitutive glycoconjugates. The structures of the main glycolipids and glycoproteins, which are species-dependent, are described. The focus is on the disturbance of the lipid membrane by existing drugs and possible new ones, in order to develop future therapeutic agents.
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Affiliation(s)
- Yari Cabezas
- Ecole Nationale Supérieure de Chimie de Rennes, CNRS, UMR 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France.
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Juchimiuk M, Kruszewska J, Palamarczyk G. Dolichol phosphate mannose synthase from the pathogenic yeast Candida albicans is a multimeric enzyme. Biochim Biophys Acta Gen Subj 2015; 1850:2265-75. [DOI: 10.1016/j.bbagen.2015.08.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Accepted: 08/12/2015] [Indexed: 11/29/2022]
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Forestier CL, Gao Q, Boons GJ. Leishmania lipophosphoglycan: how to establish structure-activity relationships for this highly complex and multifunctional glycoconjugate? Front Cell Infect Microbiol 2015; 4:193. [PMID: 25653924 PMCID: PMC4301024 DOI: 10.3389/fcimb.2014.00193] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 12/22/2014] [Indexed: 01/09/2023] Open
Abstract
A key feature of many pathogenic microorganisms is the presence of a dense glycocalyx at their surface, composed of lipid-anchored glycoproteins and non-protein-bound polysaccharides. These surface glycolipids are important virulence factors for bacterial, fungal and protozoan pathogens. The highly complex glycoconjugate lipophosphoglycan (LPG) is one of the dominant surface macromolecules of the promastigote stage of all Leishmania parasitic species. LPG plays critical pleiotropic roles in parasite survival and infectivity in both the sandfly vector and the mammalian host. Here, we review the composition of the Leishmania glycocalyx, the chemical structure of LPG and what is currently known about its effects in the mammalian host, specifically. We will then discuss the current approaches employed to elucidate LPG functions. Finally, we will provide a viewpoint on future directions that this area of investigation could take to unravel in detail the biological activity of the specific molecular elements composing the structurally complex LPG.
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Affiliation(s)
| | - Qi Gao
- Complex Carbohydrate Research Center, Department of Chemistry, University of Georgia Athens, GA, USA
| | - Geert-Jan Boons
- Complex Carbohydrate Research Center, Department of Chemistry, University of Georgia Athens, GA, USA
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Ghosh D, Stumhofer JS. Do you see what I see: Recognition of protozoan parasites by Toll-like receptors. ACTA ACUST UNITED AC 2014; 9:129-140. [PMID: 25383072 DOI: 10.2174/1573395509666131203225929] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Toll-like receptors (TLRs) are important for recognizing a variety of pathogens, including protozoan parasites, and initiating innate immune responses against them. TLRs are localized on the cell surface as well as in the endosome, and are implicated in innate sensing of these parasites. In this review, we will discuss recent findings on the identification of parasite-derived pathogen associated molecular patterns and the TLRs that bind them. The role of these TLRs in initiating the immune response against protozoan parasitic infections in vivo will be presented in the context of murine models of infection utilizing TLR-deficient mice. Additionally, we will explore evidence that TLRs and genetic variants of TLRs may impact the outcome of these parasitic infections in humans.
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Affiliation(s)
- Debopam Ghosh
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205
| | - Jason S Stumhofer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205
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Identification and functional analysis of Trypanosoma cruzi genes that encode proteins of the glycosylphosphatidylinositol biosynthetic pathway. PLoS Negl Trop Dis 2013; 7:e2369. [PMID: 23951384 PMCID: PMC3738449 DOI: 10.1371/journal.pntd.0002369] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 07/01/2013] [Indexed: 12/03/2022] Open
Abstract
Background Trypanosoma cruzi is a protist parasite that causes Chagas disease. Several proteins that are essential for parasite virulence and involved in host immune responses are anchored to the membrane through glycosylphosphatidylinositol (GPI) molecules. In addition, T. cruzi GPI anchors have immunostimulatory activities, including the ability to stimulate the synthesis of cytokines by innate immune cells. Therefore, T. cruzi genes related to GPI anchor biosynthesis constitute potential new targets for the development of better therapies against Chagas disease. Methodology/Principal Findings In silico analysis of the T. cruzi genome resulted in the identification of 18 genes encoding proteins of the GPI biosynthetic pathway as well as the inositolphosphorylceramide (IPC) synthase gene. Expression of GFP fusions of some of these proteins in T. cruzi epimastigotes showed that they localize in the endoplasmic reticulum (ER). Expression analyses of two genes indicated that they are constitutively expressed in all stages of the parasite life cycle. T. cruzi genes TcDPM1, TcGPI10 and TcGPI12 complement conditional yeast mutants in GPI biosynthesis. Attempts to generate T. cruzi knockouts for three genes were unsuccessful, suggesting that GPI may be an essential component of the parasite. Regarding TcGPI8, which encodes the catalytic subunit of the transamidase complex, although we were able to generate single allele knockout mutants, attempts to disrupt both alleles failed, resulting instead in parasites that have undergone genomic recombination and maintained at least one active copy of the gene. Conclusions/Significance Analyses of T. cruzi sequences encoding components of the GPI biosynthetic pathway indicated that they are essential genes involved in key aspects of host-parasite interactions. Complementation assays of yeast mutants with these T. cruzi genes resulted in yeast cell lines that can now be employed in high throughput screenings of drugs against this parasite. Chagas disease, considered one of the most neglected tropical diseases, is caused by the blood-borne parasite Trypanosoma cruzi and currently affects about 8 million people in Latin America. T. cruzi can be transmitted by insect vectors, blood transfusion, organ transplantation and mother-to-baby as well as through ingestion of contaminated food. Although T. cruzi causes life-long infections that can result in serious damage to the heart, the two drugs currently available to treat Chagas disease, benznidazole and nifurtimox, which have been used for more than 40 years, have proven efficacy only during the acute phase of the disease. Thus, there is an urgent need to develop new drugs that are more targeted, less toxic, and more effective against this parasite. Here we described the characterization of T. cruzi genes involved in the biosynthesis of GPI anchors, a molecule responsible for holding different types of glycoproteins on the parasite membrane. Since GPI anchored proteins are essential molecules T. cruzi uses during infection, besides helping understand how this parasite interacts with its host, this work may contribute to the development of better therapies against Chagas disease.
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Banerjee DK. N-glycans in cell survival and death: cross-talk between glycosyltransferases. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1820:1338-46. [PMID: 22326428 PMCID: PMC3499948 DOI: 10.1016/j.bbagen.2012.01.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Revised: 01/12/2012] [Accepted: 01/27/2012] [Indexed: 11/25/2022]
Abstract
Asparagine-linked (N-linked) protein glycosylation is one of the most important protein modifications. N-glycans with "high mannose", "hybrid", or "complex" type sugar chains participate in a multitude of cellular processes. These include cell-cell/cell-matrix/receptor-ligand interaction, cell signaling/growth and differentiation, to name a few. Many diseases such as disorders of blood clotting, congenital disorder of glycosylation, diseases of blood vessels, cancer, neo-vascularization, i.e., angiogenesis essential for breast and other solid tumor progression and metastasis are associated with N-glycan expression. Biosynthesis of N-glycans requires multiple steps and multiple cellular compartments. Following transcription and translation the proteins migrate to the endoplasmic reticulum (ER) lumen to acquire glycan chain(s) with a defined glycoform, i.e., a tetradecasaccharide. These are further modified, i.e., edited in ER lumen and in Golgi prior to moving to their respective destinations. The tetradecasaccharide is pre-assembled on a poly-isoprenoid lipid called dolichol, and becomes an essential component of the supply chain. Therefore, dolichol cycle synthesizing the lipid-linked oligosaccharide (LLO) is a hallmark for all N-linked glycoproteins. It is expected that there is a great deal of cross-talk between the participating glycosyltransferases and any missed step would express defective N-glycans that could have fatal consequences. The positive impact of the structurally altered N-glycans could lead to discovery of an N-glycan signature for a disease and/or help developing glycotherapeutic treating cancer or other human diseases. The purpose of this review is to identify the gaps of N-glycan biology and help developing appropriate technology for biomedical applications. This article is part of a Special Issue entitled Glycoproteomics.
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Affiliation(s)
- Dipak K Banerjee
- Department of Biochemistry, School of Medicine, University of Puerto Rico, Medical Sciences Campus, San Juan, PR 00936-5067.
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16
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de Assis RR, Ibraim IC, Nogueira PM, Soares RP, Turco SJ. Glycoconjugates in New World species of Leishmania: polymorphisms in lipophosphoglycan and glycoinositolphospholipids and interaction with hosts. Biochim Biophys Acta Gen Subj 2011; 1820:1354-65. [PMID: 22093608 DOI: 10.1016/j.bbagen.2011.11.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 10/31/2011] [Accepted: 11/01/2011] [Indexed: 11/29/2022]
Abstract
BACKGROUND Protozoan parasites of the genus Leishmania cause a number of important diseases in humans and undergo a complex life cycle, alternating between a sand fly vector and vertebrate hosts. The parasites have a remarkable capacity to avoid destruction in which surface molecules are determinant for survival. Amongst the many surface molecules of Leishmania, the glycoconjugates are known to play a central role in host-parasite interactions and are the focus of this review. SCOPE OF THE REVIEW The most abundant and best studied glycoconjugates are the Lipophosphoglycans (LPGs) and glycoinositolphospholipids (GIPLs). This review summarizes the main studies on structure and biological functions of these molecules in New World Leishmania species. MAJOR CONCLUSIONS LPG and GIPLs are complex molecules that display inter- and intraspecies polymorphisms. They are key elements for survival inside the vector and to modulate the vertebrate immune response during infection. GENERAL SIGNIFICANCE Most of the studies on glycoconjugates focused on Old World Leishmania species. Here, it is reported some of the studies involving New World species and their biological significance on host-parasite interaction. This article is part of a Special Issue entitled Glycoproteomics.
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Affiliation(s)
- Rafael Ramiro de Assis
- Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, FIOCRUZ, Av. Augusto de Lima, 1715, Belo Horizonte, MG 30190-002, Brazil
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Novozhilova NM, Bovin NV. Structure, functions, and biosynthesis of glycoconjugates of Leishmania spp. cell surface. BIOCHEMISTRY (MOSCOW) 2010; 75:686-94. [DOI: 10.1134/s0006297910060027] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Mora-Montes HM, Ponce-Noyola P, Villagómez-Castro JC, Gow NA, Flores-Carreón A, López-Romero E. Protein glycosylation in Candida. Future Microbiol 2010; 4:1167-83. [PMID: 19895219 DOI: 10.2217/fmb.09.88] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Candidiasis is a significant cause of invasive human mycosis with associated mortality rates that are equivalent to, or worse than, those cited for most cases of bacterial septicemia. As a result, considerable efforts are being made to understand how the fungus invades host cells and to identify new targets for fungal chemotherapy. This has led to an increasing interest in Candida glycobiology, with an emphasis on the identification of enzymes essential for glycoprotein and adhesion metabolism, and the role of N- and O-linked glycans in host recognition and virulence. Here, we refer to studies dealing with the identification and characterization of enzymes such as dolichol phosphate mannose synthase, dolichol phosphate glucose synthase and processing glycosidases and synthesis, structure and recognition of mannans and discuss recent findings in the context of Candida albicans pathogenesis.
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Novozhilova N, Bovin N. D-Arabinose Methabolism: Characterization of Bifunctional Arabinokinase/Pyrophosphorylase of Leishmania major. Acta Naturae 2009; 1:81-3. [PMID: 22649617 PMCID: PMC3347535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
In this work we describe an unusual enzyme from Leishmania major (Arabinokinase/Pyrophosphorylase) that catalyzes the synthesis of GDP-D-arabinopyranose (GDP-D-Arap) via a D-arabinose-1-phosphate intermediate in the presence of ATP and GTP. Our data indicate GDP-D-Arap transport in vivo by the LPG2 multispecific nucleotide sugar transporter into the Leishmania Golgi apparatus, in which it can be used by glycosyltransferases as a donor substrate for glycosylation.
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Affiliation(s)
- N.M. Novozhilova
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, RAS
| | - N.V. Bovin
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, RAS
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20
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Rodríguez AE, Couto A, Echaide I, Schnittger L, Florin-Christensen M. Babesia bovis contains an abundant parasite-specific protein-free glycerophosphatidylinositol and the genes predicted for its assembly. Vet Parasitol 2009; 167:227-35. [PMID: 19833438 DOI: 10.1016/j.vetpar.2009.09.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Autonomous glycosylphosphatidylinositol (GPI) molecules (also protein-free GPIs or free GPIs) have been reported to be particularly abundant in some parasitic protozoa and mediate strong immunomodulatory effects on the host immune system. In the work at hand we have investigated the existence of free GPIs in Babesia bovis. Comparative thin layer chromatographic analysis of the protein-free glycolipid fraction of in vitro cultured B. bovis merozoites and erythrocyte membranes demonstrated the presence of an abundant parasite-specific band. Its chemical analysis revealed a GPI species containing a chain of two mannose residues, N-glucosamine and non-acylated inositol. The lipid moiety linked to inositol was diacylglycerol. The total fatty acid composition showed predominantly long-carbon chain molecules (12% of C(22:0) and 45% of C(24:0)). The potential of B. bovis to assemble the presented free GPI species was verified by the existence of seven genes in its genome that putatively encode the following GPI biosynthetic enzymes: PI N-acetyl-GlcN-transferase (PIG-A and GPI-1), N-acetyl-GlcN-PI-de-N-acetylase (PIG-L), acyltransferase (PIG-W), dolichyl-phosphate mannosyl transferase (DPM-1), GPI mannosyltransferase I (PIG-M), and GPI mannosyltransferase II (PIG-V). GPI biosynthesis is vital for the intraerythrocytic parasite stage as mannosamine, an inhibitor of GPI biosynthesis, impaired in vitro growth of B. bovis merozoites. Absence of the vast majority of N-glycan metabolism encoding genes in the B. bovis genome underscores that the growth inhibitory effect of mannosamine is attributable to its interference with GPI biosynthesis and not with assembly of N-linked oligosaccharides, as has been described for higher eukaryotes. Elucidation of the structure and biosynthesis of GPI may allow to facilitate the development of future immune interventions against bovine babesiosis.
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Murta SMF, Vickers TJ, Scott DA, Beverley SM. Methylene tetrahydrofolate dehydrogenase/cyclohydrolase and the synthesis of 10-CHO-THF are essential in Leishmania major. Mol Microbiol 2009; 71:1386-401. [PMID: 19183277 PMCID: PMC2692627 DOI: 10.1111/j.1365-2958.2009.06610.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
10-Formyl tetrahydrofolate (10-CHO-THF) is a key metabolite in C1 carbon metabolism, arising through the action of formate-tetrahydrofolate ligase (FTL) and/or 5,10-methenyltetrahydrofolate cyclohydrolase/5,10-methylene tetrahydrofolate dehydrogenase (DHCH). Leishmania major possesses single DHCH1 and FTL genes encoding exclusively cytosolic proteins, unlike other organisms where isoforms occur in the mitochondrion as well. Recombinant DHCH1 showed typical NADP(+)-dependent methylene tetrahydrofolate DH and 5,10-methenyltetrahydrofolate CH activities, and the DH activity was potently inhibited by a substrate analogue 5,10-CO-THF (K(i) 105 nM), as was Leishmania growth (EC(50) 1.1 microM). Previous studies showed null ftl(-) mutants were normal, raising the possibility that loss of the purine synthetic pathway had rendered 10-CHO-THF dispensable in evolution. We were unable to generate dhch1(-) null mutants by gene replacement, despite using a wide spectrum of nutritional supplements expected to bypass DHCH function. We applied an improved method for testing essential genes in Leishmania, based on segregational loss of episomal complementing genes rather than transfection; analysis of approximately 1400 events without successful loss of DHCH1 again established its requirement. Lastly, we employed 'genetic metabolite complementation' using ectopically expressed FTL as an alternative source of 10-CHO-THF; now dhch1(-) null parasites were readily obtained. These data establish a requirement for 10-CHO-THF metabolism in L. major, and provide genetic and pharmacological validation of DHCH as a target for chemotherapy, in this and potentially other protozoan parasites.
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Affiliation(s)
| | | | | | - Stephen M. Beverley
- Department of Molecular Microbiology, Box 8230, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
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22
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Baksi K, Zhang Z, Banerjee A, Banerjee DK. Cloning and expression of mannosylphospho dolichol synthase from bovine adrenal medullary capillary endothelial cells. Glycoconj J 2009; 26:635-45. [PMID: 19214747 DOI: 10.1007/s10719-008-9214-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Revised: 10/21/2008] [Accepted: 10/28/2008] [Indexed: 10/21/2022]
Abstract
Mannosylphospho dolichol synthase (DPMS) is a critical enzyme in the biosynthesis of lipid-linked oligosaccharide (LLO; Glc(3)Man(9)GlcNAc(2)-PP-Dol), a pre-requisite for asparagine-linked (N-linked) protein glycosylation. We have shown earlier that DPMS is important for angiogenesis, i.e., endothelial cell proliferation. This is true when cAMP is used for intracellular signaling. During cAMP signaling, DPMS is activated and ER stress is reduced. To understand the activation of DPMS at the molecular level we have isolated a cDNA clone for the DPMS gene (bDPMS) from the capillary endothelial cells of bovine adrenal medulla. DNA sequencing and the deduced amino acid sequence have established that bDPMS has a motif to be phosphorylated by cAMP-dependent protein kinase (PKA). Based on the sequence information Serine 165 has been found to be the phosphorylation target in bDPMS. Hydropathy Index when plotted against amino acid number indicates the presence of a hydrophobic region around the amino acid residues 120-160, supporting that bDPMS has one membrane spanning region. The recombinant bDPMS has now been purified as His-tag protein with an apparent molecular weight of M (r) 33 kDa. Additionally, we show here that overexpression of DPMS is indeed angiogenic. The capillary endothelial cells proliferate at a higher rate carrying the DPMS overexpression plasmid over the parental cells or the vector.
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Affiliation(s)
- Krishna Baksi
- Department of Anatomy and Cell Biology, School of Medicine, Universidad Central del Caribe, Bayamón, PR 00930-3100, USA
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23
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Naderer T, Wee E, McConville MJ. Role of hexosamine biosynthesis inLeishmaniagrowth and virulence. Mol Microbiol 2008; 69:858-69. [DOI: 10.1111/j.1365-2958.2008.06314.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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24
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Urushibata Y, Ebisu S, Matsui I. A thermostable dolichol phosphoryl mannose synthase responsible for glycoconjugate synthesis of the hyperthermophilic archaeon Pyrococcus horikoshii. Extremophiles 2008; 12:665-76. [PMID: 18563288 DOI: 10.1007/s00792-008-0173-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2008] [Accepted: 05/08/2008] [Indexed: 11/28/2022]
Abstract
Dolichol phosphoryl mannose synthase (DPM synthase) is an essential enzyme in the synthesis of N- and O-linked glycoproteins and the glycosylphosphatidyl-inositol anchor. An open reading frame, PH0051, from the hyperthermophilic archaeon Pyrococcus horikoshii encodes a DPM synthase ortholog, PH0051p. A full-length version of PH0051p was produced using an E. coli in vitro translation system and its thermostable activity was confirmed with a DPM synthesis assay, although the in vitro productivity was not sufficient for further characterization. Then, a yeast expression vector coding for the N-terminal catalytic domain of PH0051p was constructed. The N-terminal domain, named DPM(1-237), was successfully expressed, and turned out to be a membrane-bound form in Saccharomyces cerevisiae cells, even without its hydrophobic C-terminal domain. The membrane-bound DPM(1-237) was solubilized with a detergent and purified to homogeneity. The purified DPM(1-237) showed thermostability at up to 75 degrees C and an optimum temperature of 60 degrees C. The truncated mutant DPM(1-237) required Mg(2+) and Mn(2+) ions as cofactors the same as eukaryotic DPM synthases. By site-directed mutagenesis, Asp(89) and Asp(91) located at the most conserved motif, DXD, were confirmed as the catalytic residues, the latter probably bound to a cofactor, Mg(2+). DPM(1-237) was able to utilize both acceptor lipids, dolichol phosphate and the prokaryotic carrier lipid C(55)-undecaprenyl phosphate, with Km values of 1.17 and 0.59 microM, respectively. The DPM synthase PH0051p seems to be a key component of the pathway supplying various lipid-linked phosphate sugars, since P. horikoshii could synthesize glycoproteins as well as the membrane-associated PH0051p in vivo.
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Affiliation(s)
- Yuji Urushibata
- Biological Information Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8566, Japan
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25
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Maeda Y, Kinoshita T. Dolichol-phosphate mannose synthase: Structure, function and regulation. Biochim Biophys Acta Gen Subj 2008; 1780:861-8. [DOI: 10.1016/j.bbagen.2008.03.005] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Revised: 02/11/2008] [Accepted: 03/06/2008] [Indexed: 11/30/2022]
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26
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Leishmania adaptor protein-1 subunits are required for normal lysosome traffic, flagellum biogenesis, lipid homeostasis, and adaptation to temperatures encountered in the mammalian host. EUKARYOTIC CELL 2008; 7:1256-67. [PMID: 18515754 DOI: 10.1128/ec.00090-08] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The adaptor protein-1 (AP-1) complex is involved in membrane transport between the Golgi apparatus and endosomes. In the protozoan parasite Leishmania mexicana mexicana, the AP-1 mu1 and sigma1 subunits are not required for growth at 27 degrees C but are essential for infectivity in the mammalian host. In this study, we have investigated the function of these AP-1 subunits in order to understand the molecular basis for this loss of virulence. The mu1 and sigma1 subunits were localized to late Golgi and endosome membranes of the major parasite stages. Parasite mutants lacking either AP-1 subunit lacked obvious defects in Golgi structure, endocytosis, or exocytic transport. However, these mutants displayed reduced rates of endosome-to-lysosome transport and accumulated fragmented, sterol-rich lysosomes. Defects in flagellum biogenesis were also evident in nondividing promastigote stages, and this phenotype was exacerbated by inhibitors of sterol and sphingolipid biosynthesis. Furthermore, both AP-1 mutants were hypersensitive to elevated temperature and perturbations in membrane lipid composition. The pleiotropic requirements for AP-1 in membrane trafficking and temperature stress responses explain the loss of virulence of these mutants in the mammalian host.
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27
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Sahin A, Espiau B, Tetaud E, Cuvillier A, Lartigue L, Ambit A, Robinson DR, Merlin G. The leishmania ARL-1 and Golgi traffic. PLoS One 2008; 3:e1620. [PMID: 18286177 PMCID: PMC2237903 DOI: 10.1371/journal.pone.0001620] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Accepted: 01/19/2008] [Indexed: 12/20/2022] Open
Abstract
We present here the characterisation of the Leishmania small G protein ADP-Ribosylation Factor-Like protein 1 (ARL-1). The ARL-1 gene is present in one copy per haploid genome and conserved among trypanosomatids. It encodes a protein of 20 kDa, which is equally expressed in the insect promastigote and mammalian amastigote forms of the parasite. ARL-1 localises to the Trans-Golgi Network (TGN); N-terminal myristoylation is essential for TGN localisation. In vivo expression of the LdARL-1/Q74L and LdARL-1/T51N mutants (GTP- and GDP-bound blocked forms respectively) shows that GDP/GTP cycling occurs entirely within the TGN. This is contrary to previous reports in yeast and mammals, where the mutant empty form devoid of nucleotide has been considered as the GDP-blocked form. The dominant-negative empty form mutant LdARL-1/T34N inhibits endocytosis and intracellular trafficking from the TGN to the Lysosome/Multivesicular Tubule and to the acidocalcisomes; these defects are probably related to a mislocalisation of the GRIP domain-containing vesicle tethering factors which cannot be recruited to the TGN by the cytoplasmic LdARL-1/T34N. Thus, besides the functional characterization of a new mutant and a better understanding of ARL-1 GDP/GTP cycling, this work shows that Leishmania ARL-1 is a key component of an essential pathway worth future study.
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Affiliation(s)
- Annelise Sahin
- Laboratoire de Microbiologie Cellulaire et Moléculaire et Pathogénicité, UMR CNRS 5234, Université Bordeaux 2, Bordeaux, France
| | - Benoît Espiau
- Laboratoire de Microbiologie Cellulaire et Moléculaire et Pathogénicité, UMR CNRS 5234, Université Bordeaux 2, Bordeaux, France
| | - Emmanuel Tetaud
- Laboratoire de Microbiologie Cellulaire et Moléculaire et Pathogénicité, UMR CNRS 5234, Université Bordeaux 2, Bordeaux, France
| | - Armelle Cuvillier
- Laboratoire de Microbiologie Cellulaire et Moléculaire et Pathogénicité, UMR CNRS 5234, Université Bordeaux 2, Bordeaux, France
| | - Lydia Lartigue
- Laboratoire de Microbiologie Cellulaire et Moléculaire et Pathogénicité, UMR CNRS 5234, Université Bordeaux 2, Bordeaux, France
| | - Audrey Ambit
- Laboratoire de Microbiologie Cellulaire et Moléculaire et Pathogénicité, UMR CNRS 5234, Université Bordeaux 2, Bordeaux, France
| | - Derrick R. Robinson
- Laboratoire de Microbiologie Cellulaire et Moléculaire et Pathogénicité, UMR CNRS 5234, Université Bordeaux 2, Bordeaux, France
| | - Gilles Merlin
- Laboratoire de Microbiologie Cellulaire et Moléculaire et Pathogénicité, UMR CNRS 5234, Université Bordeaux 2, Bordeaux, France
- *E-mail:
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McConville MJ, de Souza D, Saunders E, Likic VA, Naderer T. Living in a phagolysosome; metabolism of Leishmania amastigotes. Trends Parasitol 2007; 23:368-75. [PMID: 17606406 DOI: 10.1016/j.pt.2007.06.009] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 04/26/2007] [Accepted: 06/13/2007] [Indexed: 12/11/2022]
Abstract
Leishmania amastigotes primarily proliferate within macrophages in the mammalian host. Genome-based metabolic reconstructions, combined with biochemical, reverse genetic and mRNA or protein profiling studies are providing new insights into the metabolism of this intracellular stage. We propose that the complex nutritional requirements of amastigotes have contributed to the tropism of these parasites for the amino acid-rich phagolysosome of macrophages. Amastigote metabolism in this compartment is robust because many metabolic mutants are capable of either growing normally or persisting long term in susceptible animals. New approaches for measuring amastigote metabolism in vivo are discussed.
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Affiliation(s)
- Malcolm J McConville
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
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Kleczka B, Lamerz AC, van Zandbergen G, Wenzel A, Gerardy-Schahn R, Wiese M, Routier FH. Targeted gene deletion of Leishmania major UDP-galactopyranose mutase leads to attenuated virulence. J Biol Chem 2007; 282:10498-505. [PMID: 17284446 DOI: 10.1074/jbc.m700023200] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Considering the high incidence of galactofuranose (Gal(f)) in pathogens and its absence from higher eukaryotes, the enzymes involved in the biosynthesis of this unusual monosaccharide appear as attractive drug targets. However, although the importance of Gal(f) in bacterial survival or pathogenesis is established, its role in eukaryotic pathogens is still undefined. Recently, we reported the identification and characterization of the first eukaryotic UDP-galactopyranose mutases. This enzyme holds a central role in Gal(f) metabolism by providing UDP-Gal(f) to all galactofuranosyltransferases. In this work, the therapeutical potential of Gal(f) metabolism in Leishmania major was hence evaluated by targeted replacement of the GLF gene encoding UDP-galactopyranose mutase. In L. major, Gal(f) is present in the membrane anchor of the lipophosphoglycan (LPG) and in glycoinositolphospholipids. Accordingly, the generated glf(-) mutant is deficient in LPG backbone and expresses truncated glycoinositolphospholipids. These structural changes do not influence the in vitro growth of the parasite but lead to an attenuation of virulence comparable with that observed with a mutant exclusively deficient in LPG.
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Affiliation(s)
- Barbara Kleczka
- Medizinische Hochschule Hannover, Carl-Neuberg Strasse 1, 30625 Hannover, Germany
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Zacks MA, Garg N. Recent developments in the molecular, biochemical and functional characterization of GPI8 and the GPI-anchoring mechanism [review]. Mol Membr Biol 2006; 23:209-25. [PMID: 16785205 DOI: 10.1080/09687860600601494] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Glycoconjugates are utilized by eukaryotic organisms ranging from yeast to humans for the cell surface expression of a wide variety of proteins and lipids. These glycoconjugates are expressed as enzymes or receptors and serve a diversity of functions, including cell signaling and cell survival. In parasitic protozoans, glycoconjugates play roles in infectivity, survival, virulence and immune evasion. Among the alternate glycoconjugate structures that have been identified, glycosylphosphatidylinositols (GPIs) represent a universal structure for the anchorage of proteins, lipids, and phosphosaccharides to cellular membranes. Biosynthesis of the GPI is a multi-step process that culminates in the attachment of the assembled GPI to a precursor protein. This final step in the transfer of the GPI to a protein is catalyzed by GPI8 of the putative transamidase complex (TAM). GPI8 functions dually to perform the proteolytic cleavage of the C-terminal signal sequence of the precursor protein, followed by the formation of an amide bond between the protein and the ethanolamine phosphate of the GPI. This review summarizes the current aggregate of biochemical, gene-disruption and active site mutagenesis studies, which provide evidence that GPI8 is responsible for the protein-GPI anchoring reaction. We describe recently published studies that have identified other potential components of the TAM complex and that have elucidated their likely role in protein-GPI attachment. Further, we discuss the biochemical, molecular and functional differences between protozoan and mammalian GPI8 and the protein-GPI anchoring machinery. Finally, we will present the implications of these studies for the development of anti-parasite drug therapies.
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Affiliation(s)
- Michele A Zacks
- Department of Pathology, Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, Texas 77555-1070, USA
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Lamani E, Mewbourne RB, Fletcher DS, Maltsev SD, Danilov LL, Veselovsky VV, Lozanova AV, Grigorieva NY, Pinsker OA, Xing J, Forsee WT, Cheung HC, Schutzbach JS, Shibaev VN, Jedrzejas MJ. Structural studies and mechanism of Saccharomyces cerevisiae dolichyl-phosphate-mannose synthase: insights into the initial step of synthesis of dolichyl-phosphate-linked oligosaccharide chains in membranes of endoplasmic reticulum. Glycobiology 2006; 16:666-78. [PMID: 16549409 DOI: 10.1093/glycob/cwj104] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Dolichyl-phosphate-mannose (Dol-P-Man) synthase catalyzes the reversible formation of a key intermediate that is involved as a mannosyl donor in at least three different pathways for the synthesis of glycoconjugates important for eukaryotic development and viability. The enzyme is found associated with membranes of the endoplasmic reticulum (ER), where it transfers mannose from the water soluble cytoplasmic donor, guanosine 5'-diphosphate (GDP)-Man, to the membrane-bound, extremely hydrophobic, and long-chain polyisoprenoid acceptor, dolichyl-phosphate (Dol-P). The enzyme from Saccharomyces cerevisiae has been utilized to investigate the structure and activity of the protein and interactions of the enzyme with Dol-P and synthetic Dol-P analogs containing fluorescent probes. These interactions have been explored utilizing fluorescence resonance energy transfer (FRET) to establish intramolecular distances within the protein molecule as well as intermolecular distances to determine the localization of the active site and the hydrophobic substrate on the enzyme's surface. A three-dimensional (3D) model of the enzyme was produced with bound substrates, Dol-P, GDP-Man, and divalent cations to delineate the binding sites for these substrates as well as the catalytic site. The FRET analysis was used to characterize the functional properties of the enzyme and to evaluate its modeled structure. The data allowed for proposing a molecular mechanism of catalysis as an inverting mechanism of mannosyl residue transfer.
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Affiliation(s)
- Ejvis Lamani
- Children's Hospital Oakland Research Institute, CA 94609, USA
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Azzouz N, Shams-Eldin H, Niehus S, Debierre-Grockiego F, Bieker U, Schmidt J, Mercier C, Delauw MF, Dubremetz JF, Smith TK, Schwarz RT. Toxoplasma gondii grown in human cells uses GalNAc-containing glycosylphosphatidylinositol precursors to anchor surface antigens while the immunogenic Glc–GalNAc-containing precursors remain free at the parasite cell surface. Int J Biochem Cell Biol 2006; 38:1914-25. [PMID: 16822699 DOI: 10.1016/j.biocel.2006.05.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2006] [Revised: 05/10/2006] [Accepted: 05/15/2006] [Indexed: 10/24/2022]
Abstract
Toxoplasma gondii is a ubiquitous parasite that infects nearly all warm-blooded animals. Developmental switching in T. gondii, from the virulent tachyzoite to the relatively quiescent bradyzoite stage, is responsible for the disease propagation after alteration of the immune status of the carrier. The redifferentiation event is characterized by an over expression of a tachyzoite specific set of glycosylphosphatidylinositol anchored surface antigens and free GPIs. T. gondii grown in animal cells uses two glycosylphosphatidylinositol precursors to anchor the parasite surface proteins. The first form has an N-acetylgalactosamine residue bound to a conserved three-mannosyl core glycan, while the second structure contains an additional terminal glucose linked to the N-acetylgalactosamine side branch. Sera from persons infected with T. gondii reacted only with the glucose-N-acetylgalactosamine-containing structure. Here we report that T. gondii cultured in human cells uses predominantly the N-acetylgalactosamine-containing structure to anchor the parasite surface antigens. On the other hand, glycosylphosphatidylinositol structures having an additional terminal glucose are found exclusively on the parasite cell surface as free glycolipids participating in the production of cytokines that are implicated in the pathogenesis of T. gondii. We also provide evidence that such free glycosylphosphatidylinositols are restricted mainly to the lipid microdomains in the parasite cell surface membrane and mostly associated with proteins involved in the parasite motility as well as invasion of the host cell.
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Affiliation(s)
- Nahid Azzouz
- Laboratory for Organic Chemistry, Swiss Federal Institute of Technology, ETH Zurich, HCI E328, Wolfgang-Pauli-Strasse 10, 8093 Zurich, Switzerland.
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Vishwakarma RA, Anand MT, Arya R, Vats D, Bhattacharya A. Glycosylated inositol phospholipid from Entamoeba histolytica: identification and structural characterization. Mol Biochem Parasitol 2005; 145:121-4. [PMID: 16242191 DOI: 10.1016/j.molbiopara.2005.09.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 09/15/2005] [Accepted: 09/21/2005] [Indexed: 10/25/2022]
Affiliation(s)
- Ram A Vishwakarma
- Bio-organic Chemistry Lab, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India
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Salgado M, Villagómez-Castro JC, Rocha-Rodríguez R, Sabanero-López M, Ramos MA, Alagón A, López-Romero E, Sánchez-López R. Entamoeba histolytica: biochemical and molecular insights into the activities within microsomal fractions. Exp Parasitol 2005; 110:363-73. [PMID: 15913610 DOI: 10.1016/j.exppara.2005.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2004] [Revised: 03/30/2005] [Accepted: 04/02/2005] [Indexed: 11/22/2022]
Abstract
One of the most fascinating aspects of the Entamoeba histolytica trophozoite ultrastructure is the lack of a typical secretory pathway, particularly of rough endoplasmic reticulum and Golgi system, in a cell with such a high secretory activity. Here, we describe the isolation of amoeba cell structures containing ER-typical activities. Following isopycnic centrifugation of plasma membrane-free extracts, microsomes enriched in enzymatic activities such as dolichol-P-mannose synthase (DPMS; EC 2.4.1.83), UDP-GlcNAc:dolichol-P GlcNAc-1-P transferase (NAGPT; EC 2.7.8.15), and UDP-D-GlcNAc:dolichol-PP GlcNAc (NAGT; EC 2.4.1.141) were resolved from phagolysosomal fractions. Sec61alpha-subunit, an ER-marker involved in the translocation of nascent proteins to the ER, was found to co-fractionate with DPMS activity indicating that they are contained in microsomes with a similar density. Further, we optimized conditions for trophozoite homogenization and differential centrifugation that resulted in the separation of a 57,000 g-sedimenting microsomal fraction containing EhSec61alpha-subunit, EhDPMS, and EhPDI (protein disulfide isomerase, a soluble marker of the lumen of the ER). A relevant observation was the lack of ER markers associated to the nuclear fraction. Large macromolecular structures such as Ehproteasome were sedimented at a higher speed. Our knowledge of the molecular machinery involved in the biosynthesis of dolichol-linked oligosaccharide was enriched with the identification of putative genes related to the stepwise assembly of the dolichol-PP-GlcNAc(2)Man(5) core. No evidence of genes supporting further assembly steps was obtained at this time.
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Affiliation(s)
- Milena Salgado
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología (UNAM), Cuernavaca, Morelos, Mexico
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Fabre AL, Orlean P, Taron CH. Saccharomyces cerevisiae Ybr004c and its human homologue are required for addition of the second mannose during glycosylphosphatidylinositol precursor assembly. FEBS J 2005; 272:1160-8. [PMID: 15720390 DOI: 10.1111/j.1742-4658.2005.04551.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Addition of the second mannose is the only obvious step in glycosylphosphatidylinositol (GPI) precursor assembly for which a responsible gene has not been discovered. A bioinformatics-based strategy identified the essential Saccharomyces cerevisiae Ybr004c protein as a candidate for the second GPI alpha-mannosyltransferase (GPI-MT-II). S. cerevisiae cells depleted of Ybr004cp have weakened cell walls and abnormal morphology, are unable to incorporate [3H]inositol into proteins, and accumulate a GPI intermediate having a single mannose that is likely modified with ethanolamine phosphate. These data indicate that Ybr004cp-depleted yeast cells are defective in second mannose addition to GPIs, and suggest that Ybr004cp is GPI-MT-II or an essential subunit of that enzyme. Ybr004cp homologues are encoded in all sequenced eukaryotic genomes, and are predicted to have 8 transmembrane domains, but show no obvious resemblance to members of established glycosyltransferase families. The human Ybr004cp homologue can substitute for its S. cerevisiae counterpart in vivo.
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Banerjee DK, Carrasquillo EA, Hughey P, Schutzbach JS, Martínez JA, Baksi K. In vitro phosphorylation by cAMP-dependent protein kinase up-regulates recombinant Saccharomyces cerevisiae mannosylphosphodolichol synthase. J Biol Chem 2004; 280:4174-81. [PMID: 15548536 DOI: 10.1074/jbc.m406962200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
DPM1 is the structural gene for mannosylphosphodolichol synthase (i.e. Dol-P-Man synthase, DPMS) in Saccharomyces cerevisiae. Earlier studies with cDNA cloning and sequence analysis have established that 31-kDa DPMS of S. cerevisiae contains a consensus sequence (YRRVIS141) that can be phosphorylated by cAMP-dependent protein kinase (PKA). We have been studying the up-regulation of DPMS activity by protein kinase A-mediated phosphorylation in higher eukaryotes, and used the recombinant DPMS from S. cerevisiae in this study to advance our knowledge further. DPMS catalytic activity was indeed enhanced severalfold when the recombinant protein was phosphorylated in vitro. The rate as well as the magnitude of catalysis was higher with the phosphorylated enzyme. A similar increase in the catalytic activity was also observed when the in vitro phosphorylated recombinant DPMS was assayed as a function of increasing concentrations of exogenous dolichylmonophosphate (Dol-P). Kinetic studies indicated that there was no change in the Km for GDP-mannose between the in vitro phosphorylated and control recombinant DPMS, but the Vmax was increased by 6-fold with the phosphorylated enzyme. In vitro phosphorylated recombinant DPMS also exhibited higher enzyme turnover (kcat) and enzyme efficiency (kcat/Km). SDS-PAGE followed by autoradiography of the 32P-labeled DPMS detected a 31-kDa phosphoprotein, and immunoblotting with anti-phosphoserine antibody established the presence of a phosphoserine residue in in vitro phosphorylated recombinant DPMS. To confirm the phosphorylation activation of recombinant DPMS, serine 141 in the consensus sequence was replaced with alanine by PCR site-directed mutagenesis. The S141A DPMS mutant exhibited more than half-a-fold reduction in catalytic activity compared with the wild type when both were analyzed after in vitro phosphorylation. Thus, confirming that S. cerevisiae DPMS activity is indeed regulated by the cAMP-dependent protein phosphorylation signal, and the phosphorylation target is serine 141.
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Affiliation(s)
- Dipak K Banerjee
- Department of Biochemistry, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico 00936-5067.
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37
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Abstract
Summary relatively large rafts are a feature of activated mammalian cells. These studies allow us to consider the functional role of lipid rafts in kinetoplastid parasites, which are particularly rich in lipid-anchored surface molecules. Morphological, biochemical and genetic studies indicate that lipid rafts (and sphingolipid biosythesis) are important in the differentiation of extracellular Leishmania to mammalian-infective metacyclic promastigotes, perhaps orchestrating the clearly observable reorganization of the plasma membrane during this process that leads to an activated metacyclic primed for invasion. However, the first step in the sphingolipid biosynthetic pathway (mediated by serine palmitoyltransferase), and at least regulated, de novo sphingoid base and ceramide synthesis, are not essential for the pathogenesis of intramacrophage Leishmania amastigotes.
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Affiliation(s)
- Paul W Denny
- Wellcome Trust Laboratories for Molecular Parasitology, Centre for Molecular Microbiology and Infection, Department of Biological Sciences, Imperial College London, SW7 2AZ, UK
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Zhang K, Barron T, Turco SJ, Beverley SM. The LPG1 gene family of Leishmania major. Mol Biochem Parasitol 2004; 136:11-23. [PMID: 15138063 PMCID: PMC3791616 DOI: 10.1016/j.molbiopara.2004.02.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2003] [Accepted: 02/23/2004] [Indexed: 11/28/2022]
Abstract
In Leishmania major, the core of the abundant surface lipophosphoglycan (LPG) is structurally related to that of the smaller glycosylinositolphospholipids (GIPLs) in containing galactosylfuranose (Gal(f)) residues in a Gal(f) (beta1, 3)Man motif. However, deletion of the putative Gal(f)-transferase (Gal(f)T) LPG1 affected Gal(f) incorporation in LPG but not GIPLs. We hypothesized that the presumptive GIPL Gal(f)-transferases could be homologous to LPG1, and identified three related genes in the L. major genome. These were termed LPG1L, LPG1R, and LPG1G, the latter of which was found in three identical copies located at the telomeres of chromosomes 5, 19, and 32 based on Leishmania genome project data. Neither LPG1 nor its homologues LPG1L and LPG1R were involved in the biosynthesis of GIPLs, as an lpg1(-)/lpg1l(-)/lpg1r(-) triple knockout (the first such in Leishmania) grew normally and made wild-type levels of Gal(f) -containing GIPLs. In contrast, overexpression of these three led to elevated galactose incorporation in glycoproteins. Gal(f)-containing glycoproteins had not been described in Leishmania but occur at high levels in other closely related trypanosomatids including Trypanosoma cruzi, Crithidia, Leptomonas, and Endotrypanum, and LPG1L and LPG1R homologs were detected in these species. These data suggest that the glyco-synthetic capabilities of Leishmania and perhaps other trypanosomatids may be larger than previously thought, with some activities being 'cryptic' in different lineages and potentially serving as reservoirs for glycoconjugate variation during evolution. Future tests will address whether the LPG1G family encodes the hypothesized GIPL-specific Gal(f)T.
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Affiliation(s)
- Kai Zhang
- Department of Molecular Microbiology, Washington University School of Medicine, Box 8230, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - Tamara Barron
- Department of Biochemistry, University of Kentucky Medical Center, Lexington, KY 40536, USA
| | - Salvatore J. Turco
- Department of Biochemistry, University of Kentucky Medical Center, Lexington, KY 40536, USA
| | - Stephen M. Beverley
- Department of Molecular Microbiology, Washington University School of Medicine, Box 8230, 660 South Euclid Avenue, St. Louis, MO 63110, USA
- Corresponding author: Tel.: +1-314-747-2630; fax: +1-314-747-2634. (S.M. Beverley)
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Wichroski MJ, Ward GE. Biosynthesis of glycosylphosphatidylinositol is essential to the survival of the protozoan parasite Toxoplasma gondii. EUKARYOTIC CELL 2004; 2:1132-6. [PMID: 14555496 PMCID: PMC219362 DOI: 10.1128/ec.2.5.1132-1136.2003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The PIGA gene from Toxoplasma gondii has been cloned and characterized. Like mammalian PIGA, the transmembrane and C-terminal domains are sufficient to direct localization to the parasite endoplasmic reticulum. A functional copy of PIGA is required for tachyzoite viability, demonstrating that glycosylphosphatidylinositol biosynthesis is an essential process in T. gondii.
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Affiliation(s)
- Michael J Wichroski
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont 05405, USA
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Lalanne E, Honys D, Johnson A, Borner GHH, Lilley KS, Dupree P, Grossniklaus U, Twell D. SETH1 and SETH2, two components of the glycosylphosphatidylinositol anchor biosynthetic pathway, are required for pollen germination and tube growth in Arabidopsis. THE PLANT CELL 2004; 16:229-40. [PMID: 14671020 PMCID: PMC301407 DOI: 10.1105/tpc.014407] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2003] [Accepted: 10/23/2003] [Indexed: 05/17/2023]
Abstract
Glycosylphosphatidylinositol (GPI) anchoring provides an alternative to transmembrane domains for anchoring proteins to the cell surface in eukaryotes. GPI anchors are synthesized in the endoplasmic reticulum via the sequential addition of monosaccharides, fatty acids, and phosphoethanolamines to phosphatidylinositol. Deficiencies in GPI biosynthesis lead to embryonic lethality in animals and to conditional lethality in eukaryotic microbes by blocking cell growth, cell division, or morphogenesis. We report the genetic and phenotypic analysis of insertional mutations disrupting SETH1 and SETH2, which encode Arabidopsis homologs of two conserved proteins involved in the first step of the GPI biosynthetic pathway. seth1 and seth2 mutations specifically block male transmission and pollen function. This results from reduced pollen germination and tube growth, which are associated with abnormal callose deposition. This finding suggests an essential role for GPI anchor biosynthesis in pollen tube wall deposition or metabolism. Using transcriptomic and proteomic approaches, we identified 47 genes that encode potential GPI-anchored proteins that are expressed in pollen and demonstrated that at least 11 of these proteins are associated with pollen membranes by GPI anchoring. Many of the identified candidate proteins are homologous with proteins involved in cell wall synthesis and remodeling or intercellular signaling and adhesion, and they likely play important roles in the establishment and maintenance of polarized pollen tube growth.
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Affiliation(s)
- Eric Lalanne
- Department of Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
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41
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Zufferey R, Allen S, Barron T, Sullivan DR, Denny PW, Almeida IC, Smith DF, Turco SJ, Ferguson MAJ, Beverley SM. Ether phospholipids and glycosylinositolphospholipids are not required for amastigote virulence or for inhibition of macrophage activation by Leishmania major. J Biol Chem 2003; 278:44708-18. [PMID: 12944391 DOI: 10.1074/jbc.m308063200] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ether phospholipids are major components of the membranes of humans and Leishmania. In protozoan parasites they occur separately or as part of the glycosylphosphatidylinositol (GPI) anchor of molecules implicated in virulence, such as lipophosphoglycan (LPG), smaller glycosylinositolphospholipids (GIPLs), and GPI-anchored proteins. We generated null mutants of the Leishmania major alkyldihydroxyacetonephosphate synthase (ADS), the first committed step of ether lipid synthesis. Enzymatic analysis and comprehensive mass spectrometric analysis showed that ads1- knock-outs lacked all ether phospholipids, including plasmalogens, LPG, and GIPLs. Leishmania ads1- thus represents the first ether lipid-synthesizing eukaryote for which a completely null mutant could be obtained. Remarkably ads1- grew well and maintained lipid rafts (detergent-resistant membranes). In virulence tests it closely resembled LPG-deficient L. major, including sensitivity to complement and an inability to survive the initial phase of macrophage infection. Likewise it retained the ability to inhibit host cell signaling and to form infectious amastigotes from the few parasites surviving the establishment defect. These findings counter current proposals that GIPLs are required for amastigote survival in the mammalian host or that parasite lyso-alkyl or alkylacyl-GPI anchors are solely responsible for inhibition of macrophage activation.
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Affiliation(s)
- Rachel Zufferey
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Eisenhaber B, Maurer-Stroh S, Novatchkova M, Schneider G, Eisenhaber F. Enzymes and auxiliary factors for GPI lipid anchor biosynthesis and post-translational transfer to proteins. Bioessays 2003; 25:367-85. [PMID: 12655644 DOI: 10.1002/bies.10254] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
GPI lipid anchoring is an important post-translational modification of eukaryote proteins in the endoplasmic reticulum. In total, 19 genes have been directly implicated in the anchor synthesis and the substrate protein modification pathway. Here, the molecular functions of the respective proteins and their evolution are analyzed in the context of reported literature data and sequence analysis studies for the complete pathway (http://mendel.imp.univie.ac.at/SEQUENCES/gpi-biosynthesis/) and questions for future experimental investigation are discussed. Studies of two of these proteins have provided new mechanistic insights. The cytosolic part of PIG-A/GPI3 has a two-domain alpha/beta/alpha-layered structure; it is suggested that its C-terminal subsegment binds UDP-GlcNAc whereas the N-terminal domain interacts with the phosphatidylinositol moiety. The lumenal part of PIG-T/GPI16 apparently consists of a beta-propeller with a central hole that regulates the access of substrate protein C termini to the active site of the cysteine protease PIG-K/GPI8 (gating mechanism) as well as of a polypeptide hook that embraces PIG-K/GPI8. This structural proposal would explain the paradoxical properties of the GPI lipid anchor signal motif and of PIG-K/GPI8 orthologs without membrane insertion regions in some species.
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Affiliation(s)
- Birgit Eisenhaber
- Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, A-1030 Vienna, Republic Austria
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Naderer T, McConville MJ. Characterization of a Leishmania mexicana mutant defective in synthesis of free and protein-linked GPI glycolipids. Mol Biochem Parasitol 2002; 125:147-61. [PMID: 12467982 DOI: 10.1016/s0166-6851(02)00236-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The cell surface of the promastigote stage of the protozoan parasite, Leishmania mexicana is coated by a number of glycosylphosphatidylinositol (GPI)-anchored proteins, a GPI-anchored lipophosphoglycan (LPG) and an abundant class of free GPIs, termed glycoinositolphospholipids (GIPLs). We have developed a new screen for isolating L. mexicana mutants that are defective in GPI biosynthesis, involving concanavalin A selection of a parental strain with a modified surface coat. One mutant was isolated that lacked the major GIPL species and mature GPI-protein anchor precursors, but synthesized normal levels of LPG anchor precursors. Based on analysis of apolar GIPLs that accumulate in this mutant and in vivo and in vitro synthesized GPIs, this mutant was found to have a defect in the addition of an alpha1-6 linked mannose to the common precursor, Man(1)GlcN-PI. The apolar GIPLs were transported to the cell surface with the same kinetics as mature GIPLs. However, non-anchored isoforms of the major GPI-anchored protein, gp63, were either slowly secreted (with a t(1/2) of 2 h) or retained within the endoplasmic reticulum, respectively. These findings suggest that common enzymes are involved in the synthesis of GIPLs and protein anchors and have implications for understanding how the biosynthesis of the major surface components of these parasites is regulated.
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Affiliation(s)
- Thomas Naderer
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Vic. 3010, Australia
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44
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Ralton JE, Mullin KA, McConville MJ. Intracellular trafficking of glycosylphosphatidylinositol (GPI)-anchored proteins and free GPIs in Leishmania mexicana. Biochem J 2002; 363:365-75. [PMID: 11931667 PMCID: PMC1222488 DOI: 10.1042/0264-6021:3630365] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Free glycosylphosphatidylinositols (GPIs) are an important class of membrane lipids in many pathogenic protozoa. In this study, we have investigated the subcellular distribution and intracellular trafficking of an abundant class of free GPIs [termed glycosylinositolphospholipids (GIPLs)] in Leishmania mexicana promastigotes. The intracellular transport of the GIPLs and the major GPI-anchored glycoprotein gp63 was measured by following the incorporation of these molecules into sphingolipid-rich, detergent-resistant membranes (DRMs) in the plasma membrane. In metabolic-labelling experiments, mature GIPLs and gp63 were transported to DRMs in the plasma membrane with a t(1/2) of 70 and 40 min, respectively. Probably, GIPL transport to the DRMs involves a vesicular mechanism, as transport of both the GIPLs and gp63 was inhibited similarly at 10 degrees C. All GIPL intermediates were quantitatively recovered in Triton X-100-soluble membranes and were largely orientated on the cytoplasmic face of the endoplasmic reticulum, as shown by their sensitivity to exogenous phosphatidylinositol-specific phospho-lipase C. On the contrary, a significant proportion of the mature GIPLs ( approximately 50% of iM4) were accessible to membrane-impermeable probes on the surface of live promastigotes. These results suggest that the GIPLs are flipped across intracellular or plasma membranes during surface transport and that a significant fraction may populate the cytoplasmic leaflet of the plasma membrane. Finally, treatment of L. mexicana promastigotes with myriocin, an inhibitor of sphingolipid biosynthesis, demonstrated that ongoing sphingolipid biosynthesis is not required for the plasma-membrane transport of either gp63 or the GIPLs and that DRMs persist even when cellular levels of the major sphingolipid are depleted by 70%.
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Affiliation(s)
- Julie E Ralton
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010, Australia
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McConville MJ, Mullin KA, Ilgoutz SC, Teasdale RD. Secretory pathway of trypanosomatid parasites. Microbiol Mol Biol Rev 2002; 66:122-54; table of contents. [PMID: 11875130 PMCID: PMC120783 DOI: 10.1128/mmbr.66.1.122-154.2002] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The Trypanosomatidae comprise a large group of parasitic protozoa, some of which cause important diseases in humans. These include Trypanosoma brucei (the causative agent of African sleeping sickness and nagana in cattle), Trypanosoma cruzi (the causative agent of Chagas' disease in Central and South America), and Leishmania spp. (the causative agent of visceral and [muco]cutaneous leishmaniasis throughout the tropics and subtropics). The cell surfaces of these parasites are covered in complex protein- or carbohydrate-rich coats that are required for parasite survival and infectivity in their respective insect vectors and mammalian hosts. These molecules are assembled in the secretory pathway. Recent advances in the genetic manipulation of these parasites as well as progress with the parasite genome projects has greatly advanced our understanding of processes that underlie secretory transport in trypanosomatids. This article provides an overview of the organization of the trypanosomatid secretory pathway and connections that exist with endocytic organelles and multiple lytic and storage vacuoles. A number of the molecular components that are required for vesicular transport have been identified, as have some of the sorting signals that direct proteins to the cell surface or organelles in the endosome-vacuole system. Finally, the subcellular organization of the major glycosylation pathways in these parasites is reviewed. Studies on these highly divergent eukaryotes provide important insights into the molecular processes underlying secretory transport that arose very early in eukaryotic evolution. They also reveal unusual or novel aspects of secretory transport and protein glycosylation that may be exploited in developing new antiparasite drugs.
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Affiliation(s)
- Malcolm J McConville
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
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Bütikofer P, Vassella E, Boschung M, Renggli CK, Brun R, Pearson TW, Roditi I. Glycosylphosphatidylinositol-anchored surface molecules of Trypanosoma congolense insect forms are developmentally regulated in the tsetse fly. Mol Biochem Parasitol 2002; 119:7-16. [PMID: 11755181 DOI: 10.1016/s0166-6851(01)00382-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Procyclic culture forms of Trypanosoma congolense have been shown to express a glutamic acid/alanine-rich protein (GARP) on their surface. By labelling T. congolense procyclic culture forms with glycosylphosphatidylinositol (GPI) precursors, we show that GARP is bound to the membrane by a GPI anchor and demonstrate the presence of two additional GPI-anchored surface molecules of 24-34 and 58 kDa that are abundantly expressed. The 24-34 kDa molecule, which is recognised by monoclonal antibodies that bind to the surface of living trypanosomes, is resistant to proteolysis, suggesting that it consists (predominantly) of non-proteinaceous material. We have therefore named it protease-resistant surface molecule (PRS). In common with the EP and GPEET procyclins of Trypanosoma brucei, the relative expression of the T. congolense GPI-anchored molecules changes during parasite development in the tsetse fly. PRS is abundantly expressed by procyclic trypanosomes in the midgut shortly after infection, but is downregulated in established midgut forms and completely absent from the epimastigote form in the proboscis. In contrast, GARP is downregulated in parasites in the tsetse fly midgut, but upregulated in the epimastigote form. Unexpectedly, 14 days post-infection, procyclic forms frequently are negative for both PRS and GARP, suggesting that they might be expressing another stage-specific surface antigen at this point in the life cycle.
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Affiliation(s)
- Peter Bütikofer
- Institute of Biochemistry and Molecular Biology, University of Bern, Bühlstrasse 28, 3012, Bern, Switzerland.
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47
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Garami A, Mehlert A, Ilg T. Glycosylation defects and virulence phenotypes of Leishmania mexicana phosphomannomutase and dolicholphosphate-mannose synthase gene deletion mutants. Mol Cell Biol 2001; 21:8168-83. [PMID: 11689705 PMCID: PMC99981 DOI: 10.1128/mcb.21.23.8168-8183.2001] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Leishmania parasites synthesize an abundance of mannose (Man)-containing glycoconjugates thought to be essential for virulence to the mammalian host and for viability. These glycoconjugates include lipophosphoglycan (LPG), proteophosphoglycans (PPGs), glycosylphosphatidylinositol (GPI)-anchored proteins, glycoinositolphospholipids (GIPLs), and N-glycans. A prerequisite for their biosynthesis is an ample supply of the Man donors GDP-Man and dolicholphosphate-Man. We have cloned from Leishmania mexicana the gene encoding the enzyme phosphomannomutase (PMM) and the previously described dolicholphosphate-Man synthase gene (DPMS) that are involved in Man activation. Surprisingly, gene deletion experiments resulted in viable parasite lines lacking the respective open reading frames (DeltaPMM and DeltaDPMS), a result against expectation and in contrast to the lethal phenotype observed in gene deletion experiments with fungi. L. mexicana DeltaDPMS exhibits a selective defect in LPG, protein GPI anchor, and GIPL biosynthesis, but despite the absence of these structures, which have been implicated in parasite virulence and viability, the mutant remains infectious to macrophages and mice. By contrast, L. mexicana DeltaPMM are largely devoid of all known Man-containing glycoconjugates and are unable to establish an infection in mouse macrophages or the living animal. Our results define Man activation leading to GDP-Man as a virulence pathway in Leishmania.
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Affiliation(s)
- A Garami
- Max-Planck-Institut für Biologie, Abteilung Membranbiochemie, 72076 Tübingen, Federal Republic of Germany
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48
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Abstract
Leishmania have a digenetic life cycle, involving a motile, extracellular stage (promastigote) which parasitises the alimentary tract of a sandfly vector. Bloodfeeding activity by an infected sandfly can result in transmission of infective (metacyclic) promastigotes to mammalian hosts, including humans. Leishmania promastigotes are rapidly phagocytosed but may survive and transform into non-motile amastigote forms which can persist as intracellular parasites. Leishmania amastigotes multiply in an acidic intracellular compartment, the parasitophorous vacuole. pH plays a central role in the developmental switch between promastigote and amastigote stages, and amastigotes are metabolically most active when their environment is acidic, although the cytoplasm of the amastigote is regulated at near-neutral pH by an active process of proton extrusion. A steep proton gradient is thus maintained across the amastigote surface and all membrane processes must be adapted to function under these conditions. Amastigote uptake systems for glucose, amino acids, nucleosides and polyamines are optimally active at acidic pH. Promastigote uptake systems are kinetically distinct and function optimally at more neutral environmental pH, indicating that membrane transport activity is developmentally regulated. The nutrient environment encountered by amastigotes is not well understood but the parasitophorous vacuole can fuse with endosomes, phagosomes and autophagosomes, suggesting that a diverse range of macromolecules will be present. The parasitophorous vacuole is a hydrolytic compartment in which such material will be rapidly degraded to low molecular weight components which are typical substrates for membrane transporters. Amastigote surface transporters must compete for these substrates with equivalent host transporters in the membrane of the parasitophorous vacuole. The elaboration of accumulative transporters with high affinity will be beneficial to amastigotes in this environment. The influence of environmental pH on membrane transporter function is discussed, with emphasis on the potential role of a transmembrane proton gradient in active, high affinity transport.
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Affiliation(s)
- R J Burchmore
- Institute of Biomedical and Life Sciences, Division of Infection and Immunity, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, UK.
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49
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El Alaoui H, Bata J, Peyret P, Vivarès CP. Encephalitozoon cuniculi (Microspora): characterization of a phospholipid metabolic pathway potentially linked to therapeutics. Exp Parasitol 2001; 98:171-9. [PMID: 11560410 DOI: 10.1006/expr.2001.4635] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Phospholipid metabolism of the microsporidian Encephalitozoon cuniculi, an obligate intracellular parasite, has been investigated. Labeled precursor incorporation experiments have shown that phosphatidylserine decarboxylase and phosphatidylethanolamine N-methyltransferase are more active in cells infected by E. cuniculi than in uninfected cells. In contrast, no difference was observed in the activity of Kennedy pathway's enzymes, the mammalian pathway. This suggests the occurrence in microsporidia of a bacteria- and fungi-typical pathway for phospholipid synthesis, which is supported by the identification of two genes implicated in this pathway, the cds gene encoding the key enzyme CDP-diacylglycerol synthase (E.C. 2.7.7.41) and the pss gene for CDP-alcohol phosphatidyltransferase. The pss gene could encode phosphatidylserine synthase (E.C. 2.7.8.8.), which catalyses the de novo synthesis of phosphatidylserine in bacteria and fungi. The complete CDP-diacylglycerol synthase messenger has been isolated and shows very short 5' and 3' untranslated regions. This is strong evidence for the functionality of a metabolic pathway which could be a potential target against microsporidia which infect humans.
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Affiliation(s)
- H El Alaoui
- Laboratoire de Parasitologie Moléculaire et Cellulaire, LBP, UMR CNRS 6023, Biologie A, 63177 Aubière Cedex, France
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50
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McKean PG, Denny PW, Knuepfer E, Keen JK, Smith DF. Phenotypic changes associated with deletion and overexpression of a stage-regulated gene family in Leishmania. Cell Microbiol 2001; 3:511-23. [PMID: 11488813 DOI: 10.1046/j.1462-5822.2001.00135.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The LmcDNA16 locus of Leishmania major contains three highly related genes HASPA1, HASPA2 and HASPB, encoding hydrophilic, acylated surface proteins and a tandem pair of unrelated sequences, SHERP1 and SHERP2, coding for a small, hydrophilic protein that localizes to the endoplasmic reticulum and outer mitochondrial membrane. Differential regulation of these genes results in expression of a subset of the HASP proteins and SHERP only in infective stage parasites. To assess the contribution of these molecules to parasite virulence, the diploid LmcDNA16 gene locus has been removed by targeted gene deletion. Homozygous null mutants have precise deletions of both alleles and exhibit no HASP or SHERP expression. They are at least as virulent as wild-type parasites in macrophage invasion and intracellular survival assays, both in vitro and in vivo. Conversely, null mutants engineered to overexpress the entire LmcDNA16 gene locus are unable to survive within the intramacrophage environment despite their differentiation into infective metacyclic parasites. Both null and overexpressing null parasites show increased sensitivity to complement-mediated lysis, suggesting perturbation of their surface architecture. Avirulence in overexpressing parasites correlates with selective depletion of a specific lipid species, decreased expression of the major surface glycoprotein GP63, but no significant downregulation of the glycoconjugate lipophosphoglycan.
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Affiliation(s)
- P G McKean
- Wellcome Trust Laboratories for Molecular Parasitology, Department of Biochemistry, Imperial College of Science, Technology and Medicine, South Kensington, London SW7 2AY, UK
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