The supply of substrates to the flight muscle of tsetse flies

Bursell, E.; Billing, K.J.C.; Hargrove, John W.; McCabe, Casey; Slack, Ella

doi:10.1016/0035-9203(73)90222-8

Cited by 11 publications

(10 citation statements)

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“…After differentiation into the procyclic form, the parasite resides in an environment that probably lacks glucose, as this is consumed rapidly (to virtual absence within 15 min) in the tsetse midgut subsequent to its taking the blood meal (9). The digestive contents of the gut are considered to be rich in amino acids, as is the tsetse hemolymph, which provides proline, the principal energy source used during flight of the tsetse fly (11). Procyclic trypanosomes have been adapted to in vitro axenic culture, usually in glucose-rich media exemplified by the commonly used SDM79 medium, which contains this sugar at 6 mM.…”

Section: Discussionmentioning

confidence: 99%

“…In the tsetse midgut, glucose is scarce but may become transiently abundant following insect blood meals. Proline is a key energy source within the tsetse fly (10,11), and it has been speculated that this is a main energy source for the procyclic form trypanosomes too (12)(13)(14). However, procyclics make efficient use of glucose, which is the preferred carbon source in the glucose-rich medium commonly used to grow these parasites (15,16).…”

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confidence: 99%

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Proline Metabolism in Procyclic Trypanosoma brucei Is Down-regulated in the Presence of Glucose

Lamour

Rivière

Coustou

et al. 2005

Journal of Biological Chemistry

202

265

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Proline metabolism has been studied in procyclic form Trypanosoma brucei. These parasites consume six times more proline from the medium when glucose is in limiting supply than when this carbohydrate is present as an abundant energy source. The sensitivity of procyclic T. brucei to oligomycin increases by three orders of magnitude when the parasites are obliged to catabolize proline in medium depleted in glucose. This indicates that oxidative phosphorylation is far more important to energy metabolism in this latter case than when glucose is available and the energy needs of the parasite can be fulfilled by substrate level phosphorylation alone. A gene encoding proline dehydrogenase, the first enzyme of the proline catabolic pathway, was cloned. RNA interference studies revealed the loss of this activity to be conditionally lethal. Proline dehydrogenase defective parasites grew as wild-type when glucose was available, but, unlike wild-type cells, they failed to proliferate using proline. In parasites grown in the presence of glucose, proline dehydrogenase activity was markedly lower than when glucose was absent from the medium. Proline uptake too was shown to be diminished when glucose was abundant in the growth medium. Wild-type cells were sensitive to 2-deoxy-D-glucose if grown using proline as the principal carbon source, but not in glucose-rich medium, indicating that this non-catabolizable glucose analogue might also stimulate repression of proline utilization. These results indicate that the ability of trypanosomes to use proline as an energy source can be regulated depending upon the availability of glucose.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Proline Metabolism in Procyclic Trypanosoma brucei Is Down-regulated in the Presence of Glucose

Lamour

Rivière

Coustou

et al. 2005

Journal of Biological Chemistry

202

265

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“…The PCF mitochondrion is well developed and has a respiratory chain, while the BSF mitochondrion is more rudimentary, does not possess a functional respiratory chain or oxidative phosphorylation, and relies on the reverse action of the ATP synthase to maintain the mitochondrial membrane potential 1-4 . Proline is the key energy source within the tse tse fly 5,6 and probably the main energy source of the PCF 7-9 through the mitochondrial generation of ATP by oxidative phosphorylation 10,11 . In contrast, glucose is abundant in the blood of the mammalian host and the parasite has adapted to the availability of this substrate by using glycolysis as the main source of ATP, with generation of pyruvate, which is mostly excreted to maintain its intracellular pH 12 .…”

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confidence: 99%

Essential regulation of cell bioenergetics in Trypanosoma brucei by the mitochondrial calcium uniporter

2013

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Mechanisms of regulation of mitochondrial metabolism in trypanosomes are not completely understood. Here we present evidence that the Trypanosoma brucei mitochondrial calcium uniporter (TbMCU) is essential for regulation of mitochondrial bioenergetics, autophagy, and cell death, even in the bloodstream forms that are devoid of a functional respiratory chain and oxidative phosphorylation. Localization studies reveal its co-localization with MitoTracker staining. TbMCU overexpression increases mitochondrial Ca2+ accumulation in intact and permeabilized trypanosomes, generates excessive mitochondrial reactive oxygen species (ROS), and sensitizes them to apoptotic stimuli. Ablation of TbMCU in RNAi or conditional knockout trypanosomes reduces mitochondrial Ca2+ uptake without affecting their membrane potential, increases the AMP/ATP ratio, stimulates autophagosome formation, and produces marked defects in growth in vitro and infectivity in mice, revealing its essentiality in these parasites. The requirement of TbMCU for proline and pyruvate metabolism in procyclic and bloodstream forms, respectively, reveals its role in regulation of mitochondrial bioenergetics.

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“…Outro exemplo é o observado na mosca tsé-tsé (G. morsitans), e na maioria dos insetos da ordem díptera, onde a L-prolina é o principal combustível para o processo de voo (BURSELL et al, 1973;LEHANE;AKSOY;LEVASHINA, 2004). As concentrações desse aminoácido dentro do inseto são suficientes para que as formas procíclicas do T. brucei apresentem um metabolismo energético prolina-dependente (NJAGI; OLEMBO; PEARSON, 1992;WALSHE et al, 2009 No caso específico do metabolismo de prolina em T. cruzi se sabe que a sua presença em um meio condicionado, que mimetiza a urina do barbeiro (TAU), promove o processo de metaciclogênese (CONTRERAS et al, 1985).…”

Section: O Papel Da Prolina Na Relação Parasita -Hospedeirounclassified

“…Dessa forma se garante a disponibilidade de prolina de forma constante (BURSELL et al, 1973). Neste ciclo, a prolina é oxidada na mitocôndria do músculo de voo e, depois regenerada no abdômen a partir de alanina (HARGROVE, 1976), sendo então transportada, de volta, através da hemolinfa (BURSELL, 1963).…”

Section: Correlação Da Atividade Tcp5cdh E a Bioenergética Do T Cruziunclassified

Caracterização funcional e papel fisiológico da D1-pirrolina-5-carboxilato desidrogenase de Trypanosoma cruzi: uma enzima do metabolismo de prolina.

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AGRADECIMENTOSAo Ariel, chefe e amigo, pela oportunidade dada na formação do seu grupo e, sobretudo, por haver me ensinado a fazer ciência; À Beth pela sua enorme disposição para o bom funcionamento do laboratório e sua grata amizade;A minha colega e amiga, Lisvane Paes com que compartilhamos muitas experiências dentro e fora da bancada; À Juli Barisón pela sua amizade e coleguismo;Aos que passaram pelo lab. 024: Robert, Josué, Anahí, Jean, Inga, Denise, Julia C., André H. e aqueles que ainda fazem deste um lugar agradável para trabalhar: Lets, Roxi, Lud, Flá, Marcell, Raissa, Higo, Thales, Carolina. Aos nossos colegas Alemães com quem agora conformamos o UDD, Carsten, Kamila, Jasmin e Frank.Ao Prof. Erick Bastos (IQ/USP) pela amizade e as suas grandes contribuições na parte química;

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The supply of substrates to the flight muscle of tsetse flies

Cited by 11 publications

References 0 publications

Proline Metabolism in Procyclic Trypanosoma brucei Is Down-regulated in the Presence of Glucose

Proline Metabolism in Procyclic Trypanosoma brucei Is Down-regulated in the Presence of Glucose

Essential regulation of cell bioenergetics in Trypanosoma brucei by the mitochondrial calcium uniporter

Caracterização funcional e papel fisiológico da D1-pirrolina-5-carboxilato desidrogenase de Trypanosoma cruzi: uma enzima do metabolismo de prolina.

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