Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology
| Autor: | Carlos A. Buscaglia, Andrés B. Lantos, Pablo Ruiz Diaz, Hai Yu, Beatriz Araoz, Juan Mucci, Carolyn R. Bertozzi, Mariano L. Bossi, Xi Chen, Giannina Carlevaro, Oscar Campetella, María de los Milagros Camara |
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| Přispěvatelé: | McConville, Malcolm J |
| Rok vydání: | 2016 |
| Předmět: |
Protozoology
Molting Pathology and Laboratory Medicine Biochemistry Mass Spectrometry Mice TRANS-SIALIDASE Cell-Derived Microparticles 2.2 Factors relating to the physical environment Aetiology lcsh:QH301-705.5 Inbred BALB C Protozoans chemistry.chemical_classification Organic Compounds Glycobiology Lipids 3. Good health Medical Microbiology Physical Sciences Protozoan Life Cycles Cellular Structures and Organelles Infection Pathogen Motility Virulence Factors Immunology Carbohydrates Microbiology Fluorescence Ciencias Biológicas 03 medical and health sciences Genetics Molecular Biology Glycoproteins Animal Mucin Organisms Chemical Compounds Mucins Biology and Life Sciences Proteins Sialic acid Vector-Borne Diseases carbohydrates (lipids) 030104 developmental biology Microscopy Fluorescence chemistry Parasitology Physiological Processes lcsh:RC581-607 Glycoprotein Developmental Biology 0301 basic medicine Life Cycles Physiology Glycoconjugate MUCIN Image Processing purl.org/becyt/ford/1 [https] chemistry.chemical_compound Computer-Assisted Medicine and Health Sciences Image Processing Computer-Assisted Trypanosoma Cruzi Mice Inbred BALB C Microscopy biology Virulence Monosaccharides Chemistry Infectious Diseases Flagella Pathogens CIENCIAS NATURALES Y EXACTAS Research Article lcsh:Immunologic diseases. Allergy Trypanosoma Otras Ciencias Biológicas Trypanosoma cruzi Neuraminidase Host-Parasite Interactions Rare Diseases Virology Parasitic Diseases Animals Chagas Disease purl.org/becyt/ford/1.6 [https] MEMBRANE PROTEINS 030102 biochemistry & molecular biology Organic Chemistry Cell Biology Trypomastigotes biology.organism_classification Parasitic Protozoans N-Acetylneuraminic Acid Disease Models Animal Good Health and Well Being lcsh:Biology (General) Membrane protein Disease Models Sialic Acids N-Acetylneuraminic acid |
| Zdroj: | PLoS pathogens, vol 12, iss 4 CONICET Digital (CONICET) Consejo Nacional de Investigaciones Científicas y Técnicas instacron:CONICET PLoS Pathogens, Vol 12, Iss 4, p e1005559 (2016) PLoS Pathogens |
| Popis: | Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS) are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3)Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully soluble form. Author Summary Trypanosoma cruzi is a flagellated protozoan parasite whose life cycle includes stages alternating between insect and mammal hosts. The membrane of the infective trypomastigote is equipped to allow survival in blood and to invade cells where it proliferates. Here we provide a novel description of the localization in separate microdomains of the trans-sialidase and mucins, enzyme and substrate, respectively, that play the main role in the crucial scavenging of sialic acids from the host, which allows parasite survival and infection. Even though these proteins, key in the parasite biology, share similar anchoring to the membrane, their puzzling segregation evidences the complexity of the trypanosome virulence mechanisms and protein trafficking. Instead of as soluble proteins, they are shed in microvesicles, a finding relevant to their known role in the pathogenesis of T. cruzi infection. This work provides an integrated view that explores these phenomena at the nanoscale and allows to build a model for the trypomastigote membrane physiology. |
| Databáze: | OpenAIRE |
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