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Brosson S, Fontaine F, Vermeersch M, Perez-Morga D, Pays E, Bousbata S, Salmon D. Specific Endocytosis Blockade of Trypanosoma cruzi Exposed to a Poly-LAcNAc Binding Lectin Suggests that Lectin-Sugar Interactions Participate to Receptor-Mediated Endocytosis. PLoS One 2016; 11:e0163302. [PMID: 27685262 PMCID: PMC5042520 DOI: 10.1371/journal.pone.0163302] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 09/07/2016] [Indexed: 12/25/2022] Open
Abstract
Trypanosoma cruzi is a protozoan parasite transmitted by a triatomine insect, and causing human Chagas disease in South America. This parasite undergoes a complex life cycle alternating between non-proliferative and dividing forms. Owing to their high energy requirement, replicative epimastigotes of the insect midgut display high endocytic activity. This activity is mainly restricted to the cytostome, by which the cargo is taken up and sorted through the endosomal vesicular network to be delivered to reservosomes, the final lysosomal-like compartments. In African trypanosomes tomato lectin (TL) and ricin, respectively specific to poly-N-acetyllactosamine (poly-LacNAc) and β-D-galactose, allowed the identification of giant chains of poly-LacNAc in N-glycoproteins of the endocytic pathway. We show that in T. cruzi epimastigote forms also, glycoproteins of the endocytic pathway are characterized by the presence of N-linked glycans binding to both ricin and TL. Affinity chromatography using both TL and Griffonia simplicifolia lectin II (GSLII), specific to non-reducing terminal residue of N-acetylglucosamine (GlcNAc), led to an enrichment of glycoproteins of the trypanosomal endocytic pathway. Incubation of live parasites with TL, which selectively bound to the cytostome/cytopharynx, specifically inhibited endocytosis of transferrin (Tf) but not dextran, a marker of fluid endocytosis. Taken together, our data suggest that N-glycan modification of endocytic components plays a crucial role in receptor-mediated endocytosis of T. cruzi.
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Affiliation(s)
- Sébastien Brosson
- Laboratory of Molecular Parasitology, Institute of Molecular Biology and Medicine, Université Libre de Bruxelles, 12 rue des Professeurs Jeener et Brachet, B-6041 Gosselies, Belgium
| | - Frédéric Fontaine
- Laboratory of Molecular Parasitology, Institute of Molecular Biology and Medicine, Université Libre de Bruxelles, 12 rue des Professeurs Jeener et Brachet, B-6041 Gosselies, Belgium
| | - Marjorie Vermeersch
- Center for Microscopy and Molecular Imaging-CMMI, Université Libre de Bruxelles, 8 rue Adrienne Bolland, B-6041 Gosselies, Belgium
| | - David Perez-Morga
- Laboratory of Molecular Parasitology, Institute of Molecular Biology and Medicine, Université Libre de Bruxelles, 12 rue des Professeurs Jeener et Brachet, B-6041 Gosselies, Belgium
- Center for Microscopy and Molecular Imaging-CMMI, Université Libre de Bruxelles, 8 rue Adrienne Bolland, B-6041 Gosselies, Belgium
| | - Etienne Pays
- Laboratory of Molecular Parasitology, Institute of Molecular Biology and Medicine, Université Libre de Bruxelles, 12 rue des Professeurs Jeener et Brachet, B-6041 Gosselies, Belgium
| | - Sabrina Bousbata
- Laboratory of Molecular Parasitology, Institute of Molecular Biology and Medicine, Université Libre de Bruxelles, 12 rue des Professeurs Jeener et Brachet, B-6041 Gosselies, Belgium
- * E-mail: (DS); (SB)
| | - Didier Salmon
- Laboratory of Molecular Parasitology, Institute of Molecular Biology and Medicine, Université Libre de Bruxelles, 12 rue des Professeurs Jeener et Brachet, B-6041 Gosselies, Belgium
- Institute of Medical Biochemistry Leopoldo de Meis, Centro de Ciências e da Saúde, Federal University of Rio de Janeiro, Av. Brigadeiro Trompowsky, Rio de Janeiro, 21941-590, Brazil
- * E-mail: (DS); (SB)
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Gimenez AM, Gesumaría MC, Schoijet AC, Alonso GD, Flawiá MM, Racagni GE, Machado EE. Phosphatidylinositol kinase activities in Trypanosoma cruzi epimastigotes. Mol Biochem Parasitol 2015; 203:14-24. [DOI: 10.1016/j.molbiopara.2015.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 10/09/2015] [Accepted: 10/13/2015] [Indexed: 12/28/2022]
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Reyes-López M, Piña-Vázquez C, Serrano-Luna J. Transferrin: Endocytosis and Cell Signaling in Parasitic Protozoa. Biomed Res Int 2015; 2015:641392. [PMID: 26090431 DOI: 10.1155/2015/641392] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 12/18/2014] [Indexed: 12/31/2022]
Abstract
Iron is the fourth most abundant element on Earth and the most abundant metal in the human body. This element is crucial for life because almost all organisms need iron for several biological activities. This is the case with pathogenic organisms, which are at the vanguard in the battle with the human host for iron. The latest regulates Fe concentration through several iron-containing proteins, such as transferrin. The transferrin receptor transports iron to each cell that needs it and maintains it away from pathogens. Parasites have developed several strategies to obtain iron as the expression of specific transferrin receptors localized on plasma membrane, internalized through endocytosis. Signal transduction pathways related to the activation of the receptor have functional importance in proliferation. The study of transferrin receptors and other proteins with action in the signaling networks is important because these proteins could be used as therapeutic targets due to their specificity or to differences with the human counterpart. In this work, we describe proteins that participate in signal transduction processes, especially those that involve transferrin endocytosis, and we compare these processes with those found in T. brucei, T. cruzi, Leishmania spp., and E. histolytica parasites.
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Bayer-Santos E, Cunha-e-Silva NL, Yoshida N, Franco da Silveira J. Expression and cellular trafficking of GP82 and GP90 glycoproteins during Trypanosoma cruzi metacyclogenesis. Parasit Vectors 2013; 6:127. [PMID: 23634710 PMCID: PMC3652755 DOI: 10.1186/1756-3305-6-127] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 04/23/2013] [Indexed: 11/25/2022] Open
Abstract
Background The transformation of noninfective epimastigotes into infective metacyclic trypomastigotes (metacyclogenesis) is a fundamental step in the life cycle of Trypanosoma cruzi, comprising several morphological and biochemical changes. GP82 and GP90 are glycoproteins expressed at the surface of metacyclic trypomastigote, with opposite roles in mammalian cell invasion. GP82 is an adhesin that promotes cell invasion, while GP90 acts as a negative regulator of parasite internalization. Our understanding of the synthesis and intracellular trafficking of GP82 and GP90 during metacyclogenesis is still limited. Therefore, we decided to determine whether GP82 and GP90 are expressed only in fully differentiated metacyclic forms or they start to be expressed in intermediate forms undergoing differentiation. Methods Parasite populations enriched in intermediate forms undergoing differentiation were analyzed by quantitative real-time PCR, Western blot, flow cytometry and immunofluorescence to assess GP82 and GP90 expression. Results We found that GP82 and GP90 mRNAs and proteins are expressed in intermediate forms and reach higher levels in fully differentiated metacyclic forms. Surprisingly, GP82 and GP90 presented distinct cellular localizations in intermediate forms compared to metacyclic trypomastigotes. In intermediate forms, GP82 is localized in organelles at the posterior region and colocalizes with cruzipain, while GP90 is localized at the flagellar pocket region. Conclusions This study discloses new aspects of protein expression and trafficking during T. cruzi differentiation by showing that the machinery involved in GP82 and GP90 gene expression starts to operate early in the differentiation process and that different secretion pathways are responsible for delivering these glycoproteins toward the cell surface.
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Affiliation(s)
- Ethel Bayer-Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, São Paulo, SP 04023-062, Brazil
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Ambit A, Woods KL, Cull B, Coombs GH, Mottram JC. Morphological events during the cell cycle of Leishmania major. Eukaryot Cell 2011; 10:1429-38. [PMID: 21926331 DOI: 10.1128/EC.05118-11] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The morphological events involved in the Leishmania major promastigote cell cycle have been investigated in order to provide a detailed description of the chronological processes by which the parasite replicates its set of single-copy organelles and generates a daughter cell. Immunofluorescence labeling of β-tubulin was used to follow the dynamics of the subcellular cytoskeleton and to monitor the division of the nucleus via visualization of the mitotic spindle, while RAB11 was found to be a useful marker to track flagellar pocket division and to follow mitochondrial DNA (kinetoplast) segregation. Classification and quantification of these morphological events were used to determine the durations of phases of the cell cycle. Our results demonstrate that in L. major promastigotes, the extrusion of the daughter flagellum precedes the onset of mitosis, which in turn ends after kinetoplast segregation, and that significant remodelling of cell shape accompanies mitosis and cytokinesis. These findings contribute to a more complete foundation for future studies of cell cycle control in Leishmania.
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Ulrich PN, Jimenez V, Park M, Martins VP, Atwood J, Moles K, Collins D, Rohloff P, Tarleton R, Moreno SNJ, Orlando R, Docampo R. Identification of contractile vacuole proteins in Trypanosoma cruzi. PLoS One 2011; 6:e18013. [PMID: 21437209 PMCID: PMC3060929 DOI: 10.1371/journal.pone.0018013] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Accepted: 02/22/2011] [Indexed: 11/19/2022] Open
Abstract
Contractile vacuole complexes are critical components of cell volume regulation
and have been shown to have other functional roles in several free-living
protists. However, very little is known about the functions of the contractile
vacuole complex of the parasite Trypanosoma cruzi, the
etiologic agent of Chagas disease, other than a role in osmoregulation.
Identification of the protein composition of these organelles is important for
understanding their physiological roles. We applied a combined proteomic and
bioinfomatic approach to identify proteins localized to the contractile vacuole.
Proteomic analysis of a T. cruzi fraction enriched for
contractile vacuoles and analyzed by one-dimensional gel electrophoresis and
LC-MS/MS resulted in the addition of 109 newly detected proteins to the group of
expressed proteins of epimastigotes. We also identified different peptides that
map to at least 39 members of the dispersed gene family 1 (DGF-1) providing
evidence that many members of this family are simultaneously expressed in
epimastigotes. Of the proteins present in the fraction we selected several
homologues with known localizations in contractile vacuoles of other organisms
and others that we expected to be present in these vacuoles on the basis of
their potential roles. We determined the localization of each by expression as
GFP-fusion proteins or with specific antibodies. Six of these putative proteins
(Rab11, Rab32, AP180, ATPase subunit B, VAMP1, and phosphate transporter)
predominantly localized to the vacuole bladder. TcSNARE2.1, TcSNARE2.2, and
calmodulin localized to the spongiome. Calmodulin was also cytosolic. Our
results demonstrate the utility of combining subcellular fractionation,
proteomic analysis, and bioinformatic approaches for localization of organellar
proteins that are difficult to detect with whole cell methodologies. The CV
localization of the proteins investigated revealed potential novel roles of
these organelles in phosphate metabolism and provided information on the
potential participation of adaptor protein complexes in their biogenesis.
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Affiliation(s)
- Paul N. Ulrich
- Center for Tropical and Emerging Global
Diseases and Department of Cellular Biology, University of Georgia, Athens,
Georgia, United States of America
| | - Veronica Jimenez
- Center for Tropical and Emerging Global
Diseases and Department of Cellular Biology, University of Georgia, Athens,
Georgia, United States of America
| | - Miyoung Park
- Center for Tropical and Emerging Global
Diseases and Department of Cellular Biology, University of Georgia, Athens,
Georgia, United States of America
| | - Vicente P. Martins
- Center for Tropical and Emerging Global
Diseases and Department of Cellular Biology, University of Georgia, Athens,
Georgia, United States of America
| | - James Atwood
- Complex Carbohydrate Research Center,
University of Georgia, Athens, Georgia, United States of America
| | - Kristen Moles
- Center for Tropical and Emerging Global
Diseases and Department of Cellular Biology, University of Georgia, Athens,
Georgia, United States of America
| | - Dalis Collins
- Center for Tropical and Emerging Global
Diseases and Department of Cellular Biology, University of Georgia, Athens,
Georgia, United States of America
| | - Peter Rohloff
- Center for Tropical and Emerging Global
Diseases and Department of Cellular Biology, University of Georgia, Athens,
Georgia, United States of America
| | - Rick Tarleton
- Center for Tropical and Emerging Global
Diseases and Department of Cellular Biology, University of Georgia, Athens,
Georgia, United States of America
| | - Silvia N. J. Moreno
- Center for Tropical and Emerging Global
Diseases and Department of Cellular Biology, University of Georgia, Athens,
Georgia, United States of America
| | - Ron Orlando
- Complex Carbohydrate Research Center,
University of Georgia, Athens, Georgia, United States of America
| | - Roberto Docampo
- Center for Tropical and Emerging Global
Diseases and Department of Cellular Biology, University of Georgia, Athens,
Georgia, United States of America
- * E-mail:
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Sant'Anna C, Nakayasu ES, Pereira MG, Lourenço D, de Souza W, Almeida IC, Cunha-E-Silva NL. Subcellular proteomics of Trypanosoma cruzi reservosomes. Proteomics 2009; 9:1782-94. [PMID: 19288526 DOI: 10.1002/pmic.200800730] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Reservosomes are the endpoint of the endocytic pathway in Trypanosoma cruzi epimastigotes. These organelles have the particular ability to concentrate proteins and lipids obtained from medium together with the main proteolytic enzymes originated from the secretory pathway, being at the same time a storage organelle and the main site of protein degradation. Subcellular proteomics have been extensively used for profiling organelles in different cell types. Here, we combine cell fractionation and LC-MS/MS analysis to identify reservosome-resident proteins. Starting from a purified reservosome fraction, we established a protocol to isolate reservosome membranes. Transmission electron microscopy was applied to confirm the purity of the fractions. To achieve a better coverage of identified proteins we analyzed the fractions separately and combined the results. LC-MS/MS analysis identified in total 709 T. cruzi-specific proteins; of these, 456 had predicted function and 253 were classified as hypothetical proteins. We could confirm the presence of most of the proteins validated by previous work and identify new proteins from different classes such as enzymes, proton pumps, transport proteins, and others. The definition of the reservosome protein profile is a good tool to assess their molecular signature, identify molecular markers, and understand their relationship with different organelles.
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Affiliation(s)
- Celso Sant'Anna
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil
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de Souza W, Sant'Anna C, Cunha-e-Silva NL. Electron microscopy and cytochemistry analysis of the endocytic pathway of pathogenic protozoa. ACTA ACUST UNITED AC 2009; 44:67-124. [PMID: 19410686 DOI: 10.1016/j.proghi.2009.01.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Endocytosis is essential for eukaryotic cell survival and has been well characterized in mammal and yeast cells. Among protozoa it is also important for evading from host immune defenses and to support intense proliferation characteristic of some life cycle stages. Here we focused on the contribution of morphological and cytochemical studies to the understanding of endocytosis in Trichomonas, Giardia, Entamoeba, Plasmodium, and trypanosomatids, mainly Trypanosoma cruzi, and also Trypanosoma brucei and Leishmania.
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Affiliation(s)
- Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Cidade Universitária, Ilha do Fundão, Rio de Janeiro 21941-902, Brazil.
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Cunha-e-Silva N, Sant'Anna C, Pereira MG, Porto-Carreiro I, Jeovanio AL, de Souza W. Reservosomes: multipurpose organelles? Parasitol Res 2006; 99:325-7. [PMID: 16794853 DOI: 10.1007/s00436-006-0190-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Accepted: 03/09/2006] [Indexed: 12/31/2022]
Abstract
Reservosomes are endocytic organelles from Trypanosoma cruzi epimastigotes that store proteins and lipids for future use. The lack of molecular markers for the compartments of this parasite makes it difficult to clarify all reservosome functions, as they present characteristics of pre-lysosomes, lysosomes and recycling compartments.
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Affiliation(s)
- Narcisa Cunha-e-Silva
- Instituto de Biofisica Carlos Chagas Filho, CCS, Bloco G, subsolo, Universidade Federal do Rio de Janeiro, Cidade Universitaria, Rio de Janeiro, RJ, CEP 21949-900, Brazil.
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De Melo LDB, Eisele N, Nepomuceno-Silva JL, Lopes UG. TcRho1, the Trypanosoma cruzi Rho homologue, regulates cell-adhesion properties: Evidence for a conserved function. Biochem Biophys Res Commun 2006; 345:617-22. [PMID: 16690023 DOI: 10.1016/j.bbrc.2006.04.075] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2006] [Accepted: 04/17/2006] [Indexed: 10/24/2022]
Abstract
Rho proteins are members of the Ras superfamily of small GTPases. In higher eukaryotes these proteins play pivotal role in cell movement, phagocytosis, intracellular transport, cell-adhesion, and maintenance of cell morphology, mainly through the regulation of actin microfilaments. The GTPase TcRho1 is the only member of the Rho family described in human protozoan parasite Trypanosoma cruzi. We previously demonstrated that TcRho1 is actually required for differentiation of epimastigote to trypomastigote forms during the parasite cell cycle. In the present work, we describe cellular phenotypes induced by TcRho1 heterologous expression in NIH 3T3 fibroblasts. The NIH-3T3 lineages expressing the TcRho1-G15V and TcRho1-Q76L mutants displayed decreased levels of migration compared to the control lineage NIH-3T3 pcDNA3.1, a phenotype probably due to distinct cell-substrate adhesion properties expressed by the mutant cell lines. Accordingly, cell-substrate adhesion assays revealed that the mutant cell lines of NIH-3T3 expressing TcRho1-positive dominants constructions present enhanced substrate-adhesion phenotype. Furthermore, similar experiments with T. cruzi expressing TcRho1 mutants also revealed an enhancement of cell attachment. These results suggest that TcRho1 plays a conserved regulatory role in cell-substrate adhesion in both NIH-3T3 fibroblasts and T. cruzi epimastigotes. Taken together, our data corroborate the notion that TcRho1 may regulate the substrate-adhesion in T. cruzi, a critical step for successful progression of the parasite life cycle.
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Affiliation(s)
- Luiz Dione Barbosa De Melo
- Laboratório de Parasitologia Molecular, Instituto de Biofísica Carlos Chagas Filho, CCS, UFRJ, Rio de Janeiro, Brazil
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Souto-Padrón T, Lima AP, Ribeiro RDO. Effects of dibucaine on the endocytic/exocytic pathways in Trypanosoma cruzi. Parasitol Res 2006; 99:317-20. [PMID: 16612626 DOI: 10.1007/s00436-006-0192-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Accepted: 03/09/2006] [Indexed: 11/28/2022]
Abstract
Although local anesthetics (LA) are considered primarily Na+-channel blockers in the past decade, an alternative action of LA as inhibitors of fusion among compartments of the endocytic/exocytic pathways was described. In epimastigote forms of Trypanosoma cruzi, we observed that 50 mM dibucaine reduced the rates of uptake of bovine serum albumin (BSA) and immunoglobulin to 60% of control values in addition to the delay of exocytosis of cysteine proteases. Fusion among endocytic compartments was not inhibited in the presence of dibucaine because previously labeled reservosomes was loaded with a second label in sequential pulse-chase experiments. However, dibucaine reduced the degradation of BSA-gold complex in the reservosomes, which was not caused either by an inhibition of the whole proteolytic activity of the parasite or by a reduction on the expression levels of cruzipain. The immunocytochemical analysis suggested that the inhibition of the degradation of gold-labeled BSA in reservosomes could be due to a subversion of the regular traffic of proteases toward the reservosomes in dibucaine-treated cells.
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Affiliation(s)
- Thaïs Souto-Padrón
- Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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Oli MW, Cotlin LF, Shiflett AM, Hajduk SL. Serum resistance-associated protein blocks lysosomal targeting of trypanosome lytic factor in Trypanosoma brucei. Eukaryot Cell 2006; 5:132-9. [PMID: 16400175 PMCID: PMC1360256 DOI: 10.1128/ec.5.1.132-139.2006] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Trypanosoma brucei brucei is the causative agent of nagana in cattle and can infect a wide range of mammals but is unable to infect humans because it is susceptible to the innate cytotoxic activity of normal human serum. A minor subfraction of human high-density lipoprotein (HDL) containing apolipoprotein A-I (apoA-I), apolipoprotein L-I (apoL-I), and haptoglobin-related protein (Hpr) provides this innate protection against T. b. brucei infection. This HDL subfraction, called trypanosome lytic factor (TLF), kills T. b. brucei following receptor binding, endocytosis, and lysosomal localization. Trypanosoma brucei rhodesiense, which is morphologically and physiologically indistinguishable from T. b. brucei, is resistant to TLF-mediated killing and causes human African sleeping sickness. Human infectivity by T. b. rhodesiense correlates with the evolution of a resistance-associated protein (SRA) that is able to ablate TLF killing. To examine the mechanism of TLF resistance, we transfected T. b. brucei with an epitope-tagged SRA gene. Transfected T. b. brucei expressed SRA mRNA at levels comparable to those in T. b. rhodesiense and was highly resistant to TLF. In the SRA-transfected cells, intracellular trafficking of TLF was altered, with TLF being mainly localized to a subset of SRA-containing cytoplasmic vesicles but not to the lysosome. These results indicate that the cellular distribution of TLF is influenced by SRA expression and may directly determine the organism's susceptibility to TLF.
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Affiliation(s)
- Monika W Oli
- Global Infectious Disease Program, Josephine Bay Paul Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, Massachusetts 02543, USA
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Ramos FP, Araripe JR, Urményi TP, Silva R, Cunha e Silva NL, Leite Fontes CF, da Silveira JF, Rondinelli E. Characterization of RAB-like4, the first identified RAB-like protein from Trypanosoma cruzi with GTPase activity. Biochem Biophys Res Commun 2005; 333:808-17. [PMID: 15975556 DOI: 10.1016/j.bbrc.2005.05.183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2005] [Accepted: 05/26/2005] [Indexed: 11/25/2022]
Abstract
RAB proteins, which belong to the RAS superfamily, regulate exocytic and endocytic pathways of eukaryotic cells, controlling vesicle docking and fusion. Few RAB proteins have been identified in parasites. Molecular markers for cellular compartments are important to studies concerning about the protein traffic in Trypanosoma cruzi, the causal agent of Chagas disease. In this work, we describe the characterization of TcRABL4, the first RAB-like gene identified in T. cruzi (GenBank Accession No.: ), present as a single-copy gene. TcRABL4 contains all five consensus RAB motifs but lacks cysteine residues at the C terminus, which are essential to isoprenylation, an absolute prerequisite for membrane association of these proteins. TcRABL4 is a functional GTPase that is able to bind and hydrolyze GTP, and its gene is transcribed as a single 1.2 kb mRNA in epimastigotes. TcRABL4 appears to be differentially regulated in the three cell forms of the parasite, and the protein is not associated to membranes, unlike other RAB proteins. It is possible that TcRABL4 may be a member of a novel family of small GTPases.
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Affiliation(s)
- Fabiane Pereira Ramos
- Laboratório de Metabolismo Macromolecular Firmino Torres de Castro, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, Rio de Janeiro 21949-900, Brazil
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Araripe JR, Ramos FP, Cunha e Silva NL, Urményi TP, Silva R, Leite Fontes CF, da Silveira JF, Rondinelli E. Characterization of a RAB5 homologue in Trypanosoma cruzi. Biochem Biophys Res Commun 2005; 329:638-45. [PMID: 15737633 DOI: 10.1016/j.bbrc.2005.02.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2005] [Indexed: 11/30/2022]
Abstract
RAB proteins are small GTPases involved in exocytic and endocytic pathways of eukaryotic cells, controlling vesicle docking and fusion. RABs show a remarkable specificity in subcellular localization, so they can be used as molecular markers for studying protein trafficking in Trypanosoma cruzi, the causal agent of Chagas' disease. RAB5 is a component of early endosomes. It has been identified in kinetoplastids such as Trypanosoma brucei and Leishmania donovani. In this work, we describe the characterization of the complete coding sequence of a RAB5 gene homologue in T. cruzi (TcRAB5, GenBank Accession No. AY730667). It is present as a single copy gene, located at chromosomal bands XIII and XIV. TcRAB5 shares the highest degrees of similarity (71%) and identity (63%) with Trypanosoma brucei rhodesiense RAB5a and contains all five characteristic RAB motifs. TcRAB5 is transcribed as a single 1.5kb mRNA in epimastigotes. Its transcript was also detected in the other two forms of the parasite, metacyclic trypomastigotes and spheromastigotes. The recombinant TcRAB5 protein was able to bind and hydrolyze GTP. The identification of proteins involved in T. cruzi endo- and exocytic pathways may generate cellular compartment markers, an invaluable tool to better understand the vesicular transport in this parasite.
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Affiliation(s)
- Júlia Rolão Araripe
- Laboratório de Metabolismo Macromolecular Firmino Torres de Castro, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCS, Cidade Universitária, Rio de Janeiro 21949-900, Brazil
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15
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Araripe JR, Cunha e Silva NL, Leal ST, de Souza W, Rondinelli E. Trypanosoma cruzi: TcRAB7 protein is localized at the Golgi apparatus in epimastigotes. Biochem Biophys Res Commun 2004; 321:397-402. [PMID: 15358190 DOI: 10.1016/j.bbrc.2004.06.159] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2004] [Indexed: 11/15/2022]
Abstract
In mammalian cells, the Rab7 protein is a key element of late endocytic membrane traffic. Several results suggest that it is involved in the transport from early to late endosome or from late endosome to lysosome. We have previously characterized a Rab7 gene homologue (TcRAB7) in Trypanosoma cruzi. Now, using an affinity-purified antibody specific to TcRAB7 protein we have determined that it is localized at the Golgi apparatus of the parasite. Our results indicate that the T. cruzi Rab7 homologue may function in a different route than its counterparts in mammalian cells.
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Affiliation(s)
- Júlia R Araripe
- Lab. Metabolismo Macromolecular Firmino Torres de Castro, Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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16
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de Melo LDB, Nepomuceno-Silva JL, Sant'Anna C, Eisele N, Ferraro RB, Meyer-Fernandes JR, de Souza W, Cunha-e-Silva NL, Lopes UG. TcRho1 of Trypanosoma cruzi: role in metacyclogenesis and cellular localization. Biochem Biophys Res Commun 2004; 323:1009-16. [PMID: 15381100 DOI: 10.1016/j.bbrc.2004.08.197] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Indexed: 11/23/2022]
Abstract
Here we have investigated the function of TcRho1, a Rho family orthologue from the parasite Trypanosoma cruzi. We have selected parasites overexpressing wild-type TcRho1 and a truncated form of TcRho1 (TcRho1-DeltaCaaX) which is unable to undergo farnesylation and supposed to interfere with recruitment of Rho effectors to membranes. TcRho1 protein was localized at the anterior region of wild-type and TcRho1 overexpressing epimastigotes, suggesting association with the Golgi apparatus. Accordingly, parasites overexpressing TcRho1-DeltaCaaX presented cytoplasmic fluorescence. To address the function of TcRho1 during differentiation, from epimastigotes to trypomastigotes, we submitted parasites overexpressing the above-cited lineages to metacyclogenesis assays. Parasites overexpressing TcRho1-DeltaCaaX generated a discrete number of metacyclic trypomastigotes when compared with other lineages. Strikingly, TcRho1-DeltaCaaX cells died synchronously during the process of metacyclogenesis.
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Affiliation(s)
- Luiz Dione B de Melo
- Laboratório de Parasitologia Molecular, Instituto de Biofísica Carlos Chagas Filho, CCS, UFRJ, Rio de Janeiro, Brazil
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17
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Abstract
Reservosomes are endocytic compartments found in the posterior region of epimastigotes of Trypanosoma cruzi. In the differentiation from trypomastigotes to epimastigotes (reverse metacyclogenesis in vitro), one has the rare opportunity of following the biogenesis of an endocytic compartment. Metacyclic trypomastigotes incubated in LIT medium highly enriched with fetal calf serum differentiated directly to epimastigotes. In recently differentiated epimastigotes, acidic organelles were found in round compartments spread along the cell body, whereas in control epimastigotes they were found in reservosomes located in the posterior region. Ultrastructural analysis of intermediate forms showed that the cytostome and reservosomes appeared before differentiation to epimastigotes was completed. Many polymorphic reservosomes, with or without lipid inclusions, were observed from the anterior portion of the cell body, in close relationship with the Golgi complex, to the posterior region. Endocytic tracers were observed in the cytostome, flagellar pocket, vesicles, and newly formed reservosomes. Cruzipain, the main protease of T. cruzi, was localized in newly formed reservosomes and in vesicles budding from the trans-Golgi network that seem to fuse with reservosomes. Ingested gold-labeled albumin and cruzipain colocalized in recently formed reservosomes. Endocytosis and immunocytochemical analysis suggested that the endocytic and the secretory pathways may contribute to reservosome formation.
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Affiliation(s)
- Celso Sant'Anna
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janiero, Rio de Janeiro, Brazil
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18
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Torres C, Pérez-Victoria FJ, Parodi-Talice A, Castanys S, Gamarro F. Characterization of an ABCA-like transporter involved in vesicular trafficking in the protozoan parasite Trypanosoma cruzi. Mol Microbiol 2004; 54:632-46. [PMID: 15491356 DOI: 10.1111/j.1365-2958.2004.04304.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protozoan parasites are responsible of important healthy problems, among others malaria, leishmaniasis and trypanosomiasis. The present work reports the characterization of the first mammalian ATP-binding cassette transporter, subfamily A (ABCA)-like in Trypanosoma cruzi. TcABC1 is a single copy gene differentially expressed along the life cycle of the parasite, being absent in its infective form. TcABC1 localizes to the plasma membrane, flagellar pocket and intracellular vesicles. Functional studies of TcABC1 in transfected parasites suggest that the protein is implicated in intracellular trafficking, as determined by the analysis of endocytosis and exocytosis events. The accumulation of the endocytic markers FM4-64 and NBD-SM is increased in transfected parasites. Similarly, ectophosphatase and ectoATPase activities are increased in TcABC1 overproducers. Indeed, transmission electronic microscopy analysis showed a higher number of intracellular vesicles in TcABC1 transfectants. Taken together, these results suggest that the protein is involved in the endocytic and exocytic pathways of T. cruzi.
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Affiliation(s)
- Cristina Torres
- Instituto de Parasitología y Biomedicina López-Neyra, Consejo Superior de Investigaciones Científicas, Granada, Spain
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19
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Abstract
Cell fractionation, a methodological strategy for obtaining purified organelle preparations, has been applied successfully to parasitic protozoa by a number of investigators. Here we present and discuss the work of several groups that have obtained highly purified subcellular fractions from trypanosomatids, Apicomplexa and trichomonads, and whose work have added substantially to our knowledge of the cell biology of these parasites.
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Affiliation(s)
- Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-900, Brasil.
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20
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Abstract
Endocytic systems within eukaryotic cells are a diverse set of intracellular transport pathways responsible for uptake, recycling, interaction with the exocytic system and degradation of molecules. Each of these pathways requires the interaction of distinct protein components that function in macromolecule sorting, control of transport rates and in membrane biogenesis. In the second of two articles on kinetoplastida endocytosis, the endocytic system in Trypanosoma brucei is considered as a model, and the molecules that control this system and the protein components of the endocytic pathway are discussed. We also consider novel mechanisms for sorting that have been proposed to operate in trypanosomes.
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Affiliation(s)
- Gareth W Morgan
- Wellcome Trust Laboratories for Molecular Parasitology, Dept of Biological Sciences, Imperial College of Science, Technology and Medicine, London, UK
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21
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Buckner FS, Kateete DP, Lubega GW, Van Voorhis WC, Yokoyama K. Trypanosoma brucei prenylated-protein carboxyl methyltransferase prefers farnesylated substrates. Biochem J 2002; 367:809-16. [PMID: 12141948 PMCID: PMC1222931 DOI: 10.1042/bj20020277] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2002] [Revised: 07/24/2002] [Accepted: 07/25/2002] [Indexed: 11/17/2022]
Abstract
Carboxyl methylation of the C-terminal prenylated cysteine, which occurs in most farnesylated and geranylgeranylated proteins, is a reversible step and is implicated in the regulation of membrane binding and cellular functions of prenylated proteins such as GTPases. The gene coding for prenylated-protein carboxyl methyltransferase (PPMT) of the protozoan parasite Trypanosoma brucei has been cloned and expressed in the baculovirus/Sf9 cell system. The protein of 245 amino acids has 24-28% sequence identity to the orthologues from other species including human and Saccharomyces cerevisiae. Methyltransferase activity was detected in the membrane fraction from Sf9 cells infected with the recombinant baculovirus using N -acetyl- S -farnesylcysteine (AFC) and S -adenosyl[ methyl -(3)H]methionine ([(3)H]AdoMet) as substrates. Recombinant T. brucei PPMT prefers AFC to N -acetyl- S -geranylgeranylcysteine (AGGC) by 10-50-fold based on the V (max)/ K (m) values. Native PPMT activity detected in the membrane fraction from T. brucei procyclics displays similar substrate specificity ( approximately 40-fold preference for AFC over AGGC). In contrast, mouse liver PPMT utilizes both AFC and AGGC as substrates with similar catalytic efficiencies. Several cellular proteins of the T. brucei bloodstream form were shown to be carboxyl methylated in a cell-free system. Incorporation of [(3)H]methyl group from [(3)H]AdoMet into most of the proteins was significantly inhibited by AFC but not AGGC at 20 microM, suggesting that T. brucei PPMT acts on farnesylated proteins in the cell. Cells of the T. brucei bloodstream form show higher sensitivity to AFC and AGGC (EC(50)=70-80 microM) compared with mouse 3T3 cells (EC(50)>150 microM).
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22
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Morgan GW, Hall BS, Denny PW, Carrington M, Field MC. The kinetoplastida endocytic apparatus. Part I: a dynamic system for nutrition and evasion of host defences. Trends Parasitol 2002; 18:491-6. [PMID: 12473365 DOI: 10.1016/s1471-4922(02)02391-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The endocytic system of kinetoplastid parasites is a highly polarized membrane network focused on the flagellar pocket localized at one end of the cell. When first characterized, the endosomal network was envisioned as a simple system for uptake of extracellular material by fluid-phase or receptor-mediated mechanisms. Subsequently, it has become clear that the kinetoplastid endosomal system has an active and vital role in avoiding the host immune system and virulence, as well as providing the basic functions to fulfil cellular nutritional requirements. In two reviews, recent advances in the definition and comprehension of kinetoplastida endocytosis are discussed and, in Trypanosoma brucei in particular as the more developed experimental system. In Part 1, the endocytic system is considered in context of the surface molecules and their potential roles in virulence.
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Affiliation(s)
- Gareth W Morgan
- Wellcome Trust Laboratories for Molecular Parasitology, Dept of Biological Sciences, Imperial College of Science, Technology and Medicine, Exhibition Road, London, UK
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23
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Cunha-e-Silva NL, Atella GC, Porto-Carreiro IA, Morgado-Diaz JA, Pereira MG, De Souza W. Isolation and characterization of a reservosome fraction from Trypanosoma cruzi. FEMS Microbiol Lett 2002; 214:7-12. [PMID: 12204365 DOI: 10.1111/j.1574-6968.2002.tb11317.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Reservosomes are acidic compartments present at the posterior region of epimastigote forms of Trypanosoma cruzi that store proteins and lipids. During metacyclogenesis, they consume their contents and disappear. Reservosomes are rich in cruzipain, the main proteolytic enzyme of this parasite. By centrifugation in a sucrose gradient, we have obtained a highly purified subcellular fraction containing reservosomes from 5-day-old Y strain epimastigotes. Transmission electron microscopy showed that the fraction contained well-preserved organelles. The protein profile of the organelle analyzed by SDS-PAGE depicted a wide range of protein bands, predominating those corresponding to a triplet of 60-51 kDa and a doublet of 25-23 kDa. Protease activity in substrate-containing gels, in the presence or absence of protease inhibitors, showed that cysteine proteinase is enriched and very active in the purified fraction. Enzymatic assays demonstrated the absence of pyrophosphatase, an acidocalcisome marker, and succinate cytochrome c reductase, a mitochondrial marker, although these enzymes were active in other regions of the purification sucrose gradient. Thin layer chromatographic neutral lipid analysis of purified reservosomes demonstrated that the organelle stores large amounts of ergosterol and esterified cholesterol. Phospholipid analysis indicated phosphatidylcholine and phosphatidylethanolamine as the major constituents of reservosome membranes.
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Affiliation(s)
- Narcisa L Cunha-e-Silva
- Lab. Ultraestrutura Celular Hertha Meyer, Inst. Biofísica Carlos Chagas Filho, UFRJ, CCS Bloco G, Rio de Janeiro 21949-900, Brazil.
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24
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Nepomuceno-Silva JL, Yokoyama K, de Mello LD, Mendonca SM, Paixão JC, Baron R, Faye JC, Buckner FS, Van Voorhis WC, Gelb MH, Lopes UG. TcRho1, a farnesylated Rho family homologue from Trypanosoma cruzi: cloning, trans-splicing, and prenylation studies. J Biol Chem 2001; 276:29711-8. [PMID: 11359782 DOI: 10.1074/jbc.m102920200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Rho GTPases are members of the Ras superfamily and are involved in signal transduction pathways, including maintenance of cell morphology and motility, cell cycle progression, and transcription activation. We report the molecular identification in trypanosomatids (Trypanosoma cruzi) of the first member of the Rho family. The cloned Rho protein, TcRho1, shares approximately 40% homology with other members of the Rho family. Southern blot analysis revealed that TcRHO1 is a single copy gene per haploid genome, and Northern blot assays showed a transcript of 1200 nucleotides in length. Mapping the 5'-untranslated region of TcRHO1 transcripts revealed at least five different transcripts derived from differential trans-splicing. Three of the five transcripts contain the trans-splicing site within the coding region of the TcRHO1 gene. TcRho1 also contains the C-terminal sequence CQLF (CAAX motif), which is predicted to direct post-translation prenylation of the cysteine residue. A synthetic peptide containing this C-terminal motif, when tested against Q-Sepharose chromatography fractions from T. cruzi cytosol, was shown to be efficiently farnesylated, but not geranylgeranylated, despite the fact that the CAAX motif with X = Phe specifies geranylgeranylation by mammalian protein geranylgeranyltransferase I. Furthermore, immunoblot analyses of epimastigote protein with anti-S-farnesylcysteine methyl ester and anti-TcRho1 antisera strongly suggested that TcRho1 is farnesylated in vivo. The farnesylation of proteins such as Rho GTPases could be the basis for the selective cytotoxic action of protein farnesyltransferase inhibitors on trypanosomatids versus mammalian cells.
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MESH Headings
- 5' Untranslated Regions
- Amino Acid Motifs
- Amino Acid Sequence
- Animals
- Base Sequence
- Blotting, Northern
- Blotting, Southern
- Blotting, Western
- Chromatography, Agarose
- Chromosome Mapping
- Cloning, Molecular
- Cysteine/chemistry
- Electrophoresis, Polyacrylamide Gel
- Gene Library
- Immunoblotting
- Molecular Sequence Data
- Peptides/chemistry
- Phylogeny
- Protein Prenylation
- Protein Processing, Post-Translational
- Protozoan Proteins
- RNA Splicing
- RNA, Messenger/metabolism
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Transfection
- Trypanosoma cruzi/chemistry
- rho GTP-Binding Proteins/chemistry
- rho GTP-Binding Proteins/genetics
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Affiliation(s)
- J L Nepomuceno-Silva
- Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21949, Brazil
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25
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Porto-Carreiro I, Attias M, Miranda K, De Souza W, Cunha-e-Silva N. Trypanosoma cruzi epimastigote endocytic pathway: cargo enters the cytostome and passes through an early endosomal network before storage in reservosomes. Eur J Cell Biol 2000; 79:858-69. [PMID: 11139150 DOI: 10.1078/0171-9335-00112] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It has been known for many years that trypanosomatids require exogenous essential growth factors in order to divide. Two surface domains are involved in starting nutrient endocytosis: the flagellar pocket and the cytostome. Although the flagellar pocket plays a fundamental role in the endocytic process occurring in several trypanosomatids, we have shown the cytostome as the main structure involved in this process in epimastigote forms of T. cruzi. After one minute of endocytosis, cargo is still found at the cytostome entry as well as along the cytopharynx. After two, five and fifteen minutes of endocytosis, cargo was seen inside vesicles and tubules, prior to fusing with reservosomes. Three-dimensional reconstruction of these tubules and vesicles showed they are interconnected, forming an intricate and branched network, distributed from the perinuclear region to the posterior end of the cell. Whole unfixed parasites that had taken up gold-protein conjugates for fifteen minutes were washed and dried on electron microscope grids. Observation with an energy-filtering transmission electron microscope revealed long gold-filled tubules at the posterior end of the cell. Parasites treated with ammonium chloride had their intracellular traffic slowed down, which allowed us to observe many events of vesicle fusion. The acidic nature of this network was evidenced using acridine orange. Based on pH and protein uptake kinetics we propose that the vesicular-tubular network is the early endosome of Trypanosoma cruzi epimastigotes.
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Affiliation(s)
- I Porto-Carreiro
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, UFRJ, Rio de Janeiro, Brasil
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