Mitochondrial respiration and genomic analysis provide insight into the influence of the symbiotic bacterium on host trypanosomatid oxygen consumption

作者：Azevedo Martins A C; Machado A C L; Klein C C; Ciapina L; Gonzaga L; Vasconcelos A T R; Sagot M F; De Souza W; Einicker Lamas M; Galina A^*; Motta M C M

来源：Parasitology, 2015, 142(2): 352-362.

DOI：10.1017/S0031182014001139

• Symbiosis
• trypanosomatids
• bioenergetics
• electron transfer complex
• evolution

Certain trypanosomatids co-evolve with an endosymbiotic bacterium in a mutualistic relationship that is characterized by intense metabolic exchanges. Symbionts were able to respire for up to 4 h after isolation from Angomonas deanei. FCCP (carbonyl cyanide-4-(trifluoromethoxy) phenylhydrazone) similarly increased respiration in wild-type and aposymbiotic protozoa, though a higher maximal O-2 consumption capacity was observed in the symbiont-containing cells. Rotenone, a complex I inhibitor, did not affect A. deanei respiration, whereas TTFA (thenoyltrifluoroacetone), a complex II activity inhibitor, completely blocked respiration in both strains. Antimycin A and cyanide, inhibitors of complexes III and IV, respectively, abolished O-2 consumption, but the aposymbiotic protozoa were more sensitive to both compounds. Oligomycin did not affect cell respiration, whereas carboxyatractyloside (CAT), an inhibitor of the ADP-ATP translocator, slightly reduced O-2 consumption. In the A. deanei genome, sequences encoding most proteins of the respiratory chain are present. The symbiont genome lost part of the electron transport system (ETS), but complex I, a cytochrome d oxidase, and FoF1-ATP synthase remain. In conclusion, this work suggests that the symbiont influences the mitochondrial respiration of the host protozoan.

• 出版日期2015-2
• 单位INRIA