Trypanosoma cruzi trans-sialidase gene lacking C-terminal repeats and expressed in epimastigote forms

Briones, Marcelo R. S.; Egima, Claudia M.; Schenkman, Sérgio

doi:10.1016/0166-6851(95)00004-k

Cited by 37 publications

(31 citation statements)

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“…This repeat is not present in T. rangeli sialidase sequences, and no T. rangeli proteins were detected in western blot assays using an anti-SAPA monoclonal antibody (unpublished results). In T. cruzi , TSs containing SAPA repeats are present only in infective trypomastigotes [80], while the TSs purified from epimastigotes lack the SAPA domain [81]. In addition to genes encoding the catalytic TS (subgroup Tc I), the trans-sialidase/sialidase superfamily in T. cruzi comprises eight subgroups, designated TcS I to VIII [82].…”

Section: Resultsmentioning

confidence: 99%

Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

et al. 2014

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Background Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.Methodology/Principal FindingsThe T. rangeli haploid genome is ∼24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heat-shock proteins.Conclusions/SignificancePhylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets.

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Section: Resultsmentioning

confidence: 99%

Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

et al. 2014

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“…Interestingly, Triatoma and Rhodnius are definitive hosts of the protozoan parasite Trypanosoma cruzi that cause Chagas' disease in humans, and this parasite, as well as other Trypanosoma species, have sialidase activity, which is unusual among protozoa (9 -12). Trypanosoma sialidases contain the structural motives found in bacterial sialidases (11,13), suggesting that these enzymes could have a common ancestor. In addition, parsimony analysis of the conserved motifs of several Trypanosoma sialidases suggests that a common ancestor might have appeared in a protozoan living in the insect vector (14).…”

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confidence: 99%

Identification and Characterization of a Sialidase Released by the Salivary Gland of the Hematophagous Insect Triatoma infestans

Amino¹,

Porto²,

Chammas³

et al. 1998

Journal of Biological Chemistry

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Sialidases (EC 3.2.1.18) are commonly found in viruses, bacteria, fungi, protozoa, and vertebrates, but not in invertebrates. We have previously reported the presence of a new sialidase activity in the gut of exclusively hematophagous insects of the Triatoma genus, which transmit Chagas' disease (Amino, R., Acosta, A., Morita, O. M., Chioccola, V. L. P., and Schenkman, S. (1995) Glycobiology 5, 625-631). Here we show that this sialidase is present in the salivary gland of Triatoma infestans, and it is released with the saliva during the insect bite. The sialidase was purified to homogeneity (>5000 times) to a specific activity of more than 20 units/mg. It elutes from a gel filtration column with a volume corresponding to the size of 33 kDa, and it migrates as a single 26-kDa band in SDS-polyacrylamide gel electrophoresis, which is unusually smaller when compared with other known sialidases. T. infestans sialidase hydrolyzes preferentially ␣233-linked sialic acids at pH 4 -8, with maximal activity between pH 5.5 and 6.5, which is compatible with the optimal pH of secreted sialidases. The sialidase is competitively inhibited by 2-deoxy-2,3-dehydro-Nacetyl-neuraminic acid (K i ‫؍‬ 0.075 mM) and differently from many sialidases, with exception of Salmonella typhimurium sialidase, it is inhibited competitively by HEPES (K i ‫؍‬ 15 mM). The fact that T. infestans sialidase is released with the saliva and can hydrolyze sialylLewis X blood groups, which are the ligands for selectins, suggests that it might have a role in the blood feeding.

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“…It is not present in intracellular, dividing amastigotes [59], but starts to be detected when T. cruzi transforms into trypomastigotes. Sequence studies showed strong homology with the shed acute phase antigen (SAPA) [60].…”

Section: Trans-sialidasesmentioning

confidence: 99%

Glycoinositolphospholipids, Free and as Anchors of Proteins, in Trypanosoma cruzi

Lederkremer¹,

Bertello²

2001

CPD

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The most important glycoproteins of trypanosomatids are anchored by glycoinositolphospholipids (GIPLs) to their plasma membrane. In addition, free GIPLs have been described, for instance the lipopeptidophosphoglycan (LPPG) which is a major component of the surface of T. cruzi epimastigotes. An inositolphosphoceramide (IPC) is part of the LPPG and of glycoproteins present in different stages of T. cruzi. Ceramide was not found in mammal GIPL-anchors. The lipid moieties in T. cruzi anchors can be quite variable. However, no diacylglycerol (DAG) was found in contrast with the African trypanosomes. In GIPLs of epimastigotes collected at the logarithmic phase of growth both, 1-O-hexadecyl-2-O-palmitoylglycerol and ceramide were identified. Lignoceroylsphinganine is the major ceramide, however, no lignoceric acid was detected when analysing the candidate precursors IPCs, in any of the stages of T. cruzi. An alkylglycerol has been found either as a lyso species in the Tc85 glycoprotein of trypomastigotes or acylated as in the 1G7 anchor of metacyclic forms and in the mucins of epimastigote forms. The lipid in the mucins is replaced by ceramide when the parasite differentiates to metacyclic forms. Also, in the Ssp-4 glycoprotein characteristic of amastigotes, a ceramide was identified as the anchor lipid. These variations suggest that a remodelling mechanism is working in T. cruzi. On the other hand, the oligosaccharide core in the GIPLs of T. cruzi is substituted with galactofuranose. This monosaccharide is found only in the pyranose configuration in mammalian glycoproteins and glycolipids. Thus, the biosynthetic steps for the introduction of galactofuranose and ceramide in the anchors of T. cruzi are good targets for the development of therapeutic agents.

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Trypanosoma cruzi trans-sialidase gene lacking C-terminal repeats and expressed in epimastigote forms

Cited by 37 publications

References 30 publications

Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

Identification and Characterization of a Sialidase Released by the Salivary Gland of the Hematophagous Insect Triatoma infestans

Glycoinositolphospholipids, Free and as Anchors of Proteins, in Trypanosoma cruzi

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