Bioenergetic consequences of F
| Autor: | Carolina, Hierro-Yap, Karolína, Šubrtová, Ondřej, Gahura, Brian, Panicucci, Caroline, Dewar, Christos, Chinopoulos, Achim, Schnaufer, Alena, Zíková |
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| Rok vydání: | 2020 |
| Předmět: |
WT
wild type Trypanosoma brucei brucei Protozoan Proteins oxidative phosphorylation ACA ε-aminocaproic acid cDKO conditional double knock-out bioenergetics Mdm38 mitochondrial distribution and morphology protein 38 (aka YOL027C) alternative oxidase Adenosine Triphosphate mitochondrial membrane potential ROS reactive oxygen species ΔΨm mitochondrial membrane potential BNE blue native electrophoresis ATPase KCN potassium cyanide pAb polyclonal antibody Tb1 ATPaseTb1 (T. brucei FoF1–ATP synthase subunit 1) Trypanosoma brucei electron transport AAC ADP/ATP carrier mAb monoclonal antibody OSCP oligomycin sensitivity-conferring protein Membrane Potential Mitochondrial Tb2 ATPaseTb2 (T. brucei FoF1–ATP synthase subunit 2) TMRE tetramethylrhodamine ethyl ester Cell Cycle O2⋅− superoxide PCF procyclic form Mitochondria mitochondria AOX alternative oxidase Proton-Translocating ATPases H2DCFHDA dichlorodihydrofluorescein SHAM salicylhydroxamic acid BSF bloodstream form ATP synthase Energy Metabolism DDM dodecylmaltoside respiration Research Article |
| Zdroj: | The Journal of Biological Chemistry |
| ISSN: | 1083-351X |
| Popis: | Mitochondrial ATP synthase is a reversible nanomotor synthesizing or hydrolyzing ATP depending on the potential across the membrane in which it is embedded. In the unicellular parasite Trypanosoma brucei, the direction of the complex depends on the life cycle stage of this digenetic parasite: in the midgut of the tsetse fly vector (procyclic form), the FoF1–ATP synthase generates ATP by oxidative phosphorylation, whereas in the mammalian bloodstream form, this complex hydrolyzes ATP and maintains mitochondrial membrane potential (ΔΨm). The trypanosome FoF1–ATP synthase contains numerous lineage-specific subunits whose roles remain unknown. Here, we seek to elucidate the function of the lineage-specific protein Tb1, the largest membrane-bound subunit. In procyclic form cells, Tb1 silencing resulted in a decrease of FoF1–ATP synthase monomers and dimers, rerouting of mitochondrial electron transfer to the alternative oxidase, reduced growth rate and cellular ATP levels, and elevated ΔΨm and total cellular reactive oxygen species levels. In bloodstream form parasites, RNAi silencing of Tb1 by ∼90% resulted in decreased FoF1–ATPase monomers and dimers, but it had no apparent effect on growth. The same findings were obtained by silencing of the oligomycin sensitivity-conferring protein, a conserved subunit in T. brucei FoF1–ATP synthase. However, as expected, nearly complete Tb1 or oligomycin sensitivity-conferring protein suppression was lethal because of the inability to sustain ΔΨm. The diminishment of FoF1–ATPase complexes was further accompanied by a decreased ADP/ATP ratio and reduced oxygen consumption via the alternative oxidase. Our data illuminate the often diametrically opposed bioenergetic consequences of FoF1–ATP synthase loss in insect versus mammalian forms of the parasite. |
| Databáze: | OpenAIRE |
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