Mitochondrial localization of human frataxin is necessary but processing is not for rescuing frataxin deficiency in Trypanosoma brucei

摘要: Trypanosoma brucei, the agent of human sleeping sickness and ruminant nagana, is most genetically tractable representative domain Excavata. It evolutionarily very distant from humans, with a last common ancestor over 1 billion years ago. Frataxin, highly conserved small protein involved in iron-sulfur cluster synthesis, present both organisms, its deficiency responsible for Friedreich's ataxia humans. We have found that T. brucei growth-inhibition phenotype caused by down-regulated frataxin rescued means frataxin. The rescue fully dependent on being imported into trypanosome mitochondrion. Processing mitochondrial processing peptidase can be blocked mutations signal peptide, as cells. Although cells must processed to execute function, same mitochondrion functional even absence processing. Our results illuminate remarkable conservation mechanisms import