Trypanosoma cruzi glycosomal glyceraldehyde-3-phosphate dehydrogenase does not conform to the ‘hotspot’ topogenic signal model.

Kendall, G M; Wilderspin, Andrew F.; Ashall, Frank; Miles, Michael A.; Kelly, John M.

doi:10.1002/j.1460-2075.1990.tb07462.x

Cited by 128 publications

(80 citation statements)

References 46 publications

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“…In order to circumvent this difficulty, an attempt has been made to determine stable isoenzyme and DNA marker of these clones, such as polymorphisms of DNA sequences encoding the glycolytic enzymes piruvate kynase 2 , fructose bi-phosphate aldolase 19 , glucose phosphate isomerase 18 and glyceraldehyde-3-phosphate dehydrogenase 16 for each parasite population 17 . In conclusion, we believe that additional behavioral and molecular markers are required for further characterization of the various T. cruzi clones present in the parasite stocks derived from Chagas disease patients.…”

Section: Discussionmentioning

confidence: 99%

Diversity of Trypanosoma cruzi stocks and clones derived from Chagas disease patients: I-Behavioral characterization in vitro

Lauria-Pires

Santana

Tavares

et al. 1997

Rev. Soc. Bras. Med. Trop.

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In this study, we isolated Trypanosoma cruzi from chronic Chagas heart disease and from megaesophagus patients. The parasite stock hSLU239 (heart disease) yielded clones h1 and h2, whereas stock mSLU142 (megaesophagus) yielded clones m1, m2, m3 and m4. The parasite growth kinetics, doubling time and differentiation in axenic liquid medium showed broad behavioral diversity. It was shown that a particular pattern of behavior for a parental stock could not necessarily be assigned for subsequent clones. This study indicates that i) each Chagas disease patient is infected with several T. cruzi populations; ii) clonal lines derived from patient samples may have different biological characteristics from the original isolate; and that iii) additional behavioral and/or molecular markers are required for further characterization of Trypanosoma cruzi stocks and clones derived from Chagas disease patients in order to identify correlations with pathology.
Neste estudo, foram obtidos estoques de Trypanosoma cruzi de pacientes chagásicos com a doença cardíaca ou com megaesôfago. O estoque hSLU239 (doença cardíaca) forneceu os clones h1 e h2, enquanto o estoque mSLU142 (megaesôfago) forneceu os clones m1, m2, m3 e m4. A cinética de crescimento do parasito, tempo de duplicação e diferenciação em meio líquido axênico mostraram ampla diversidade comportamental. Observou-se que um padrão particular de comportamento de um estoque parental podia não ser necessariamente encontrado na linhagem subclonal subseqüente. Este estudo indica que i) cada paciente chagásico é infectado com várias subpopulações de T. cruzi; ii) linhagens clonais derivadas de cada estoque do parasito podem ter características biológicas diferentes do isolado original de paciente chagásico; e que iii) marcadores comportamentais e/ou moleculares adicionais são necessários para melhor caracterização de estoques de T. cruzi e seus clones derivados de pacientes com doença de Chagas, a fim de identificar as possíveis correlações com a patologia

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Section: Discussionmentioning

confidence: 99%

Diversity of Trypanosoma cruzi stocks and clones derived from Chagas disease patients: I-Behavioral characterization in vitro

Lauria-Pires

Santana

Tavares

et al. 1997

Rev. Soc. Bras. Med. Trop.

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“…This was accomplished by cloning 511 bp of the glyceraldehyde-3-phosphate dehydrogenase intergenic region (GAP) (18) into the HindIII site separating the 5Ј-TcPI-PLC and Neo r marker. T. cruzi genomic DNA was used as template and PCR was performed using forward primer 5Ј-CCAAGCTTAGGCGTGGCGATGACTTCAG-3Ј and reverse primer 5Ј-CCAAGCTTAAATTCTGTTCAATGTAATT-3Ј, which both attached HindIII sites to the PCR product.…”

Section: Methodsmentioning

confidence: 99%

A Lipid-modified Phosphoinositide-specific Phospholipase C (TcPI-PLC) Is Involved in Differentiation of Trypomastigotes to Amastigotes of Trypanosoma cruzi

Okura

Fang

Salto

et al. 2005

Journal of Biological Chemistry

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The phosphoinositide-specific phospholipase C (PI-PLC) is an important component of the inositol phosphate/diacylglycerol signaling pathway. A newly discovered Trypanosoma cruzi PI-PLC (TcPI-PLC) is lipid modified in its N terminus, targeted to its plasma membrane, and believed to play a role in differentiation of the parasite because its expression increases during the differentiation of trypomastigote to amastigote stages. To determine whether TcPI-PLC is involved in this differentiation step, antisense inhibition using phosphorothioate-modified oligonucleotides, and overexpression of the gene were performed. Antisense oligonucleotidetreated parasites showed a reduced rate of differentiation in comparison to controls, as well as accumulation of intermediate forms. Overexpression of TcPI-PLC led to a faster differentiation rate. In contrast, overexpression of a mutant TcPI-PLC that lacked the lipid modification at its N terminus did not affect the differentiation rate. Therefore, TcPI-PLC is involved, when expressed in the plasma membrane, in the differentiation of trypomastigotes to amastigotes, an essential step for the intracellular replication of these parasites.Phosphatidylinositol-specific phospholipase C (PI-PLC) 1 catalyzes the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP 2 ) to the second messengers diacylglycerol and inositol 1,4,5-trisphosphate (IP 3 ) (1). Diacylglycerol is the physiological activator of protein kinase C (2), and IP 3 induces the release of Ca 2ϩ from internal stores (3). Together, these second messengers cause an increase in phosphorylation of proteins that result in a cellular response. This pathway, also known as the inositol phosphate/diacylglycerol pathway, is known to regulate a large array of cellular processes, including metabolism, secretion, contraction, neural activity, and proliferation (1).Previous research has indicated that some of the signaling components of the inositol phosphate/diacylglycerol signal pathway are present in Trypanosoma cruzi, the etiologic agent of Chagas disease, and seem to be associated with cell differentiation. T. cruzi has three main developmental stages, the epimastigote that is found in the insect vector and can be grown in axenic culture, the amastigote or intracellular form, which lives in the cytosol of nucleated cells, and the trypomastigote, which is the terminal differentiation stage in the vector (metacyclic form) or is found in the bloodstream of mammalian hosts (bloodstream form). Ca 2ϩ stimulated IP 3 and diacylglycerol formation in digitonin-permeabilized epimastigotes of T. cruzi, thus suggesting the presence of a PI-PLC (4). Protein kinase C activities were characterized in T. cruzi epimastigotes (5, 6) and could be resolved into three subtypes in hydroxylapatite columns (6). The enzyme isoforms require phosphatidylserine and Ca 2ϩ for activity and are stimulated by diacylglycerol (5, 6). The presence of significant amounts of inositol phosphates in amastigotes (7) and much lower amounts in trypomastigotes (8) was al...

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“…T. cruzi epimastigotes were grown as described (17). Transformed T. cruzi were maintained in the same medium with 200 g ml Ϫ1 of G418.…”

Section: Methodsmentioning

confidence: 99%

Trypanosoma cruzi expresses a plant-like ascorbate-dependent hemoperoxidase localized to the endoplasmic reticulum

Wilkinson

Obado

Maurício

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

133

116

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In most aerobic organisms hemoperoxidases play a major role in H 2O2-detoxification, but trypanosomatids have been reported to lack this activity. Here we describe the properties of an ascorbate-dependent hemoperoxidase (TcAPX) from the American trypanosome Trypanosoma cruzi. The activity of this plant-like enzyme can be linked to the reduction of the parasite-specific thiol trypanothione by ascorbate in a process that involves nonenzymatic interaction. The role of heme in peroxidase activity was demonstrated by spectral and inhibition studies. Ascorbate could saturate TcAPX activity indicating that the enzyme obeys Michaelis-Menten kinetics. Parasites that overexpressed TcAPX activity were found to have increased resistance to exogenous H 2O2. To determine subcellular location an epitope-tagged form of TcAPX was expressed in T. cruzi, which was observed to colocalize with endoplasmic reticulum resident chaperone protein BiP. These findings identify an arm of the oxidative defense system of this medically important parasite. The absence of this redox pathway in the human host may be therapeutically exploitable.

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Trypanosoma cruzi glycosomal glyceraldehyde-3-phosphate dehydrogenase does not conform to the ‘hotspot’ topogenic signal model.

Cited by 128 publications

References 46 publications

Diversity of Trypanosoma cruzi stocks and clones derived from Chagas disease patients: I-Behavioral characterization in vitro

Diversity of Trypanosoma cruzi stocks and clones derived from Chagas disease patients: I-Behavioral characterization in vitro

A Lipid-modified Phosphoinositide-specific Phospholipase C (TcPI-PLC) Is Involved in Differentiation of Trypomastigotes to Amastigotes of Trypanosoma cruzi

Trypanosoma cruzi expresses a plant-like ascorbate-dependent hemoperoxidase localized to the endoplasmic reticulum

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