Toxoplasma gondii devoid of an apicoplast

Several medically relevant Apicomplexa critically rely on the apicoplast, a remnant plastid organelle derived from secondary endosymbiosis. The apicoplast has lost its photosynthetic function but harbors essential metabolic pathways. Here, we characterize the four output-generating pathways in the Toxoplasma gondii apicoplast as well as an accessory pathway and identify conditions that bypass these. While the organelle was considered indispensable for T. gondii, bypassing all pathways renders the apicoplast obsolete. We demonstrate here that T. gondii devoid of an apicoplast (T. gondii–Apico) can be maintained indefinitely in culture and be exploited to probe the organelle’s functions. Apicoplast loss was achieved through treatment with actinonin which targets the metalloprotease FtsH1 required for apicoplast maintenance and function. Quantitative proteomic analyses of T. gondii–Apico provide unprecedented insights into adaptation mechanisms following loss of the organelle and uncover ~100 putative apicoplast proteins, revealed by their reduced abundance in parasites lacking the organelle. Additionally, T. gondii–Apico display reduced sensitivity to compounds that act on the organelle, facilitating the identification of compounds that target the apicoplast. The continuous culture of T. gondii lacking its plastid organelle opens new avenues to dissect the apicoplast and device new strategies to target the apicomplexans. This study characterized the metabolism and proteome of T. gondii lacking an apicoplast. Proteomic data was collected at the Proteomics Facility of the Centre Medical Universitaire of the University of Geneva. Fatty acids and polar metabolites were analysed by GC-MS in the laboratory of Prof. Dominique Soldati-Favre, experiments conducted by Joachim Kloehn. Information regarding the samples, harvest, derivatization, analysis can be found in the associated text files.

Organizational unit

DSF Lab

Type

Dataset

DOI

10.26037/yareta:kc446nwxifbvtb5z7l2f6tayga

License

Creative Commons Public Domain Dedication

Keywords

Toxoplasma gondii, Apicoplast, Metabolism, Proteomics, GC-MS, Fatty acids