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Alencar 2022 BEC

From Bioblast


Bioenergetics Communications        
Gnaiger 2020 BEC MitoPathways
       
Gnaiger Erich et al ― MitoEAGLE Task Group (2020) Mitochondrial physiology. Bioenerg Commun 2020.1.
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Bioenergetics Communications
Publications in the MiPMap
Alencar MB, Ramos EV, Silber AM, Zíková A, Oliveira MF (2022) The extraordinary energy metabolism of the bloodstream Trypanosoma brucei forms: a critical review and hypothesis. Bioenerg Commun 2022.17. https://doi.org/10.26124/bec:2022-0017

» Bioenerg Commun 2022.17. Open Access pdf
published online 2022-12-05

Alencar Mayke Bezerra, Ramos Emily V, Silber Ariel M, Zikova Alena, Oliveira Marcus F (2022) Bioenerg Commun

Abstract: BEC.png https://doi.org/10.26124/bec:2022-0017
The parasite Trypanosoma brucei is the causative agent of sleeping sickness and involves an insect vector and a mammalian host through its complex life cycle. T. brucei mammalian bloodstream forms (BSF) exhibits unique metabolic features including: (1) reduced expression and activity of mitochondrial enzymes; (2) respiration mediated by the glycerol phosphate shuttle (GPSh) and the Trypanosome alternative oxidase (TAO) that is intrinsically uncoupled from generation of mitochondrial protonmotive force; (3) maintenance of mitochondrial membrane potential by ATP hydrolysis through the reversal of F1FO-ATP synthase activity; (4) strong reliance on glycolysis to meet their energy demands; (5) high susceptibility to oxidants. Here, we critically review the main metabolic features of BSF and provide a hypothesis to explain the unusual metabolic network and its biological significance for this parasite form. We postulate that intrinsically uncoupled respiration provided by the GPSh-TAO system acts as a preventive antioxidant defense by limiting mitochondrial superoxide production and complementing the NADPH-dependent scavenging antioxidant defenses to maintain redox balance. Given the uncoupled nature of the GPSh-TAO system, BSF avoids cell death processes by maintaining mitochondrial protonmotive force through the reversal of ATP synthase activity using the ATP generated by glycolysis. This unique “metabolic design” in BSF has no biological parallel outside of trypanosomatids and highlights the enormous diversity of the parasite mitochondrial processes to adapt to distinct environments.
Keywords: Alternative oxidase; glycerol phosphate; reactive oxygen species; cell death; Trypanosoma brucei; mitophagy; antioxidant Bioblast editor: Tindle-Solomon L O2k-Network Lab: BR Sao Paulo Silber AM, BR Rio de Janeiro Oliveira MF

ORCID: ORCID.png Alencar MB, ORCID.png Silber Ariel M, ORCID.png Zikova Alena, ORCID.png Oliveira Marcus F

MitoFit Preprint

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Labels:


Organism: Protists 



Pathway: Gp 


AOX, Trypanosoma brucei, glycerophosphate shuttle, BEC