Taleva 2015 Abstract MiP2015

A new look at the bioenergetics of the bloodstream Trypanosoma brucei mitochondrion.

Link:

Taleva GT, Veselikova M, Panicucci B, Zikova A (2015)

Event: MiP2015

The infective bloodstream stage (BS) of Trypanosoma brucei possesses a single reduced mitochondrion that lacks the proton pumping respiratory complexes III and IV. Interestingly, the essential mitochondrial (mt) membrane potential (∆_ψm) is maintained by a reverse activity of FoF1-ATPase, which translocates H⁺ into the intermembrane space at the expense of ATP. Meanwhile, dyskinetoplastic (Dk) trypanosomes lacking the mt encoded A6, an essential subunit of the F_o proton pore, alternatively maintain their ∆_ψm by combining the hydrolytic activity of the matrix-facing F₁-ATPase and the electrogenic exchange of ATP4- for ADP3- by the ADP/ATP carrier (AAC). While the AAC protein expression levels do not significantly differ between BS and Dk trypanosomes, the sensitivity of these cells to AAC inhibitor carboxyatractyloside was approximately 40-folds higher for Dk cells compared BS trypanosomes. This result would suggest that AAC activity is not as important for BS as for Dk cells and thus the ATP for maintaining the ∆_ψm in BS cells is provided by mt substrate phosphorylation pathway(s). Indeed, RNAi silencing of AAC in BS trypanosomes has neither effect on growth in vitro nor on ∆_ψm. Which of the mt substrate phosphorylation pathway(s) for ATP production are important in BS trypanosomes is being further investigated and the revisited mt energy metabolism map of the infectious stage of the parasite will be presented.

• O2k-Network Lab: CZ Ceske Budejovice Zikova A

Labels: MiParea: mt-Biogenesis;mt-density, mtDNA;mt-genetics, Comparative MiP;environmental MiP 

Organism: Protists 

Event: D1  MiP2015 

Affiliations

Biol Centre ASCR v.v.i., Inst Parasitology Univ South Bohemia, Fac Sc, Ceske Budejovice, Czech Republic. - [email protected]