Endosymbiosis in trypanosomatids: the bacterium regulates the intermediate and oxidative metabolism of the host cell.

Endosymbiosis in trypanosomatids involves a mutualistic association between a symbiotic bacterium and a host protozoan and represents an excellent model for studying metabolic coevolution and the origin of organelles. This work investigated the influence of the symbiont on the metabolism of IMPORTANCE: This work provides groundbreaking insights into the metabolic and evolutionary dynamics of endosymbiosis, a topic of central importance to cellular evolution. Angomonas deanei, a trypanosomatid species, has become a paradigm for investigating the evolution of eukaryotic cells and the origin of organelles through endosymbiosis. Harbored in the cytoplasm of this protozoan, the symbiont engages in intricate metabolic exchanges, offering a time window to analyze the processes and evolutionary history that underlie the establishment of permanent endosymbiotic relationships. By employing a multidisciplinary approach, we have uncovered how the symbiotic bacterium regulates the oxidative metabolism of the trypanosomatid, integrating glucose catabolism and optimizing energy production. Our discoveries have broad implications for understanding the metabolic integration of organelles, such as mitochondria and glycosomes, with the bacterial endosymbiont. Beyond unravelling the complexities of metabolic adaptations during symbiosis, our work may contribute to the general understanding of the evolutionary dynamics of parasitism within the Trypanosomatidae family.