Acidocalcisomes of Trypanosomatids have Species-Specific Elemental Composition

Miranda, Kildare; Docampo, Roberto; Grillo, Orlando Nelson; Souza, Wanderley de

doi:10.1078/1434461042650361

Cited by 36 publications

(31 citation statements)

References 28 publications

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“…Using X-ray mapping, it has been shown that that acidocalcisomes contain calcium, phosphorous, sodium, potassium and zinc. In some trypanosomatids, iron has also been found (Miranda et al 2004).…”

Section: The Acidocalcisomementioning

confidence: 99%

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Structural organization of Trypanosoma cruzi

Souza

2009

Mem. Inst. Oswaldo Cruz

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Section: The Acidocalcisomementioning

confidence: 99%

“…When conventional methods of processing of samples for electron microscopy are used part of the dense material is released and the structure appears as partially empty. Bars = 1.0 µm and 100 nm, respectively (Miranda et al 2004). …”

Section: Lipid Inclusionsmentioning

confidence: 99%

Structural organization of Trypanosoma cruzi

Souza

2009

Mem. Inst. Oswaldo Cruz

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“…In a previous work, we reported the structural properties and the elemental composition of acidocalcisomes in L. wallacei [17]. In the present work, a pyrophosphate-driven proton uptake in acidocalcisomes of promastigote forms of L. wallacei was characterized.…”

Section: Introductionmentioning

confidence: 94%

“…As shown before [17], X-ray microanalysis of the dense vacuoles showed a considerable amount of sodium, magnesium, phosphorus, potassium, calcium, iron, zinc, and oxygen (Fig. 1).…”

Section: Electron Microscopy Characterization Of Acidocalcisomesmentioning

confidence: 99%

“…Acidocalcisomes are calcium-rich acidic organelles first described in Trypanosoma brucei [6] and Trypanosoma cruzi [12], and then in several other trypanosomatids such as Leishmania [10,13,14], Phytomonas [11,15], Herpetomonas [16], Crithidia, Blastocrithidia, and Leptomonas [17], in apicomplexan parasites such as Plasmodium [18,19] and Toxoplasma [20][21][22], in other unicellular organisms such as Chlamydomonas reinhardtii [23], Dictyostelium discoideum [24], and in the bacteria Agrobacterium tumefaciens [25] and Rhodospirillum rubrum [26]. Acidification of acidocalcisomes is promoted by a V-type proton ATPase (V-H + -ATPase) [27,28] and a V-type pyrophosphatase (V-H + -PPase) [8,10].…”

Section: Introductionmentioning

confidence: 99%

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Kinetics of pyrophosphate-driven proton uptake by acidocalcisomes of Leptomonas wallacei

Moreira

Medeiros

Miranda

et al. 2005

Biochemical and Biophysical Research Communications

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In this work, we show the kinetics of pyrophosphate-driven H + uptake by acidocalcisomes in digitonin-permeabilized promastigotes of Leptomonas wallacei. The vacuolar proton pyrophosphatase activity was optimal in the pH range of 7.5-8.0, was inhibited by imidiodiphosphate, and was completely dependent on K + and PPi. H + was released with the addition of Ca 2+ , suggesting the presence of a Ca 2+ /H + antiport. In addition, X-ray elemental mapping associated with energy-filtering transmission electron microscopy showed that most of the Ca, Na, Mg, P, K, Fe, and Zn were located in acidocalcisomes. L. wallacei immunolabeled with antibodies against Trypanosoma cruzi pyrophosphatase show intense fluorescence in cytoplasmatic organelles of size and distribution similar to the acidocalcisomes. Altogether, the results show that L. wallacei acidocalcisomes possess a H + -pyrophosphatase with characteristics of type I V-H + -PPase. However, we did not find any evidence, either for the presence of H + -ATPases or for Na + /H + exchangers in these acidocalcisomes. Ó 2005 Elsevier Inc. All rights reserved. The trypanosomatidae family comprises unicellular eukaryotes that are able to infect a broad range of organisms such as mammalians, fishes, plants, and insects causing a wide spectrum of diseases of social, economical, and medical importance. Leptomonas wallacei is a trypanosomatid parasite that was first isolated by Romeiro et al. [1] from the intestinal tract of the phytophagous hemipteran Oncopeltus fasciatus and since then has been used as a model for studies of the interaction between trypanosomatids and the midgut of the insect vector [2,3]. A remarkable characteristic of these parasites is their ability to form cysts. They occur mainly as promastigotes but can differentiate into cystic forms, which suggests that they represent latent forms of the parasite, protecting it from extreme environmental conditions [1], which include variations on the concentration of ionic species, osmotic pressure, and pH, faced by the parasite in the different portions of the insect gut during the course of infection.Control of intracellular pH in trypanosomatids occurs through the action of proton uptake/release mechanisms located either in the plasma membrane or in intracellular compartments. These include electrogenic proton pumps, proton/ion exchangers, and HCO 3 À and chloride channels [4]. The electrogenic proton pumps comprise the P-type proton ATPase (P-ATPase) 0006-291X/$ -see front matter Ó

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Polyphosphate Storage and Function in Acidocalcisomes

Docampo

2016

Inorganic Polyphosphates in Eukaryotic Cells

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Acidocalcisomes of Trypanosomatids have Species-Specific Elemental Composition

Cited by 36 publications

References 28 publications

Structural organization of Trypanosoma cruzi

Structural organization of Trypanosoma cruzi

Kinetics of pyrophosphate-driven proton uptake by acidocalcisomes of Leptomonas wallacei

Polyphosphate Storage and Function in Acidocalcisomes

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