Two special organelles found in Trypanosoma cruzi

Souza, Wanderley de; Porto, Isabel Carreiro; Miranda, Kildare; e, Narcisa L. Silva Cunha

doi:10.1590/s0001-37652000000300016

Cited by 17 publications

(12 citation statements)

References 48 publications

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“…In contrast to what has been described for acidocalcisomes of other parasites [20,45,46], the acidification of the lumen of the organelle was exerted only by a H + -PPase. There was no evidence of an ATP-driven H + transport (Fig.…”

Section: Discussioncontrasting

confidence: 89%

“…The size, distribution and elemental composition of the electron dense organelles was the first indication that they corresponded to acidocalcisomes [18][19][20]. V-H + -PPases have been shown to localize in vacuoles of higher plants cells [34,41], and in acidocalcisomes [11,25,31] and plasma membrane of trypanosomatids [23].…”

Section: Immunolocalization Of the H + -Ppasementioning

confidence: 99%

“…These acidic organelles are electron dense, posses a surrounding membrane, have variable size, ranging from 200 ± S.E. 90 nm of diameter, and contain very high amounts of Mg, Ca, Na, Zn and short and long chain polyphosphates and low amounts of Cl, K and sulfur [for reviews see [18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

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A proton pumping pyrophosphatase in acidocalcisomes of Herpetomonas sp.

Medeiros

Moreira

Miranda

et al. 2005

Molecular and Biochemical Parasitology

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Acidocalcisomes are acidic calcium storage organelles found in several microorganisms. They are characterized by their acidic nature, high electron density, high content of polyphosphates and several cations. Electron microscopy contrast tuned images of Herpetomonas sp. showed the presence of several electron dense organelles ranging from 100 to 300 nm in size. In addition, X-ray element mapping associated with energy-filtering transmission electron microscopy showed that most of the cations, namely Na, Mg, P, K, Fe and Zn, are located in their matrix. Using acridine orange as an indicator dye, a pyrophosphate-driven H + uptake was measured in cells permeabilized by digitonin. This uptake has an optimal pH of 6.5-6.7 and was inhibited by sodium fluoride (NaF) and imidodiphosphate (IDP), two H + -pyrophosphatase inhibitors. H + uptake was not promoted by ATP. Addition of 50 M Ca 2+ induced the release of H + , suggesting the presence of a Ca 2+ /H + countertransport system in the membranes of the acidic compartments. Na + was unable to release protons from the organelles. The pyrophosphate-dependent H + uptake was dependent of ion K + and inhibited by Na + Herpetomonas sp. immunolabeled with monoclonal antibodies raised against a Trypanosoma cruzi V-H + -pyrophosphatase shows intense fluorescence in cytoplasmatic organelles of size and distribution similar to the electron-dense vacuoles.Together, these results suggest that the electron dense organelles found in Herpetomonas sp. are homologous to the acidocalcisomes described in other trypanosomatids. They possess a vacuolar H + -pyrophosphatase and a Ca 2+ /H + antiport. However, in contrast to the other trypanosomatids so far studied, we were not able to measure any ATP promoted H + transport in the acidocalcisomes of this parasite.

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Section: Discussioncontrasting

confidence: 89%

Section: Immunolocalization Of the H + -Ppasementioning

confidence: 99%

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A proton pumping pyrophosphatase in acidocalcisomes of Herpetomonas sp.

Medeiros

Moreira

Miranda

et al. 2005

Molecular and Biochemical Parasitology

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“…These were first described in Trypanosoma brucei (Vercesi et al 1994) and Trypanosoma cruzi (Docampo et al 1995) and then shown to be present in different members of the Trypanosomatidae family, in apicomplexan parasites (reviewed in Moreno 1999, 2001;De Souza et al 2000), in other unicellular eukaryotes such as the slime mold Dictyostelium discoideum (Marchesini et al 2002) and the green algae Chlamydomonas rheinardtii (Ruiz et al 2001a), and more recently in the bacterium Agrobacterium tumefaciens (Seufferheld et al 2003). Acidocalcisomes of some of these cells are characterized by possessing a vacuolartype H + -ATPase and/or a vacuolar H + -pyrophosphatase for proton uptake, a Ca 2+ /H + countertransporting ATPase for Ca 2+ uptake, and a Ca 2+ /nH + antiporter for Ca 2+ release (Vercesi et al 1994;Docampo et al 1995;Lu et al 1997, Scott andRodrigues et al 1999a, b).…”

Section: Introductionmentioning

confidence: 99%

“…Several functions have been attributed to the acidocalcisomes, such as storage of high energy compounds, calcium and other cations, and regulation of intracellular pH and cellular osmolarity (reviewed in Moreno 1999, 2001;De Souza et al 2000, LeFurgey et al 2001. Acidocalcisomes have also been shown to have a dynamic distribution during human foreskin fibroblast invasion by Toxoplasma gondii and adopt a collar-like appearance upon initiation of infection (Drozdowicz et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Dynamics of polymorphism of acidocalcisomes in Leishmania parasites

Miranda

Docampo

Grillo

et al. 2004

Histochemistry and Cell Biology

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Growth of Leishmania mexicana amazonensis promastigotes in different culture media resulted in structurally and chemically different acidocalcisomes. When grown in SDM-79 medium, the promastigotes showed large spherical acidocalcisomes of up to 1.2 mm diameter distributed throughout the cell. X-ray microanalysis and elemental mapping of the organelles showed large amounts of oxygen, phosphorus, sodium, potassium, magnesium, calcium, and zinc. Immunofluorescence microscopy using antisera raised against a peptide sequence of the vacuolar-type proton pyrophosphatase of Arabidopsis thaliana that is conserved in the Leishmania enzyme, indicated localization in acidocalcisomes. When cells were transferred to Warren's medium, the acidocalcisomes transformed from spherical into branched tubular organelles. The labeling pattern of the vacuolar proton-pyrophosphatase, considered as a marker for the organelle, changed accompanying the structural changes of the acidocalcisomes, and the enzyme showed an apparently lower proton-transporting activity when measured in digitonin-permeabilized promastigotes. X-ray microanalysis and elemental mapping of these structures revealed the additional presence of iron. Together, the results reveal that the morphology and composition of acidocalcisomes are greatly influenced by the culture con-ditions.

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Elemental composition of acidocalcisomes of Trypanosoma cruzi bloodstream trypomastigote forms

Corrêa

Andrade²,

Soares

2002

Parasitology Research

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The elemental composition of acidocalcisomes present in Trypanosoma cruzi bloodstream trypomastigotes was analyzed by X-ray microanalysis. Acidocalcisomes appear as electron-dense vesicles dispersed throughout the cytoplasm. X-ray microanalysis of whole cells adhered to Formvar-coated grids showed that they contained C, O, Na, Mg, P, S, Ca and Zn, although in some acidocalcisomes iron was also detected. However, in ultra-thin sections of parasites processed according to routine procedures, most elements were lost. Living parasites were incubated with gold-labeled holo-transferrin to test if the iron was taken up by receptor-mediated endocytosis. After incubation at 4 degrees C, labeling was observed only in the flagellar pocket membrane, showing that receptors to this protein are already present in bloodstream trypomastigotes. In parasites incubated at 28 degrees C no intracellular tracer was observed, despite the labeling in the flagellar pocket membrane. Our data show that some acidocalcisomes of T. cruzi bloodstream trypomastigotes contain iron and that this element was not taken up by receptor-mediated endocytosis.

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Two special organelles found in Trypanosoma cruzi

Cited by 17 publications

References 48 publications

A proton pumping pyrophosphatase in acidocalcisomes of Herpetomonas sp.

A proton pumping pyrophosphatase in acidocalcisomes of Herpetomonas sp.

Dynamics of polymorphism of acidocalcisomes in Leishmania parasites

Elemental composition of acidocalcisomes of Trypanosoma cruzi bloodstream trypomastigote forms

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