Glycosomal ABC transporter 3 (GAT3) deletion enhances the oxidative stress responses and reduces the infectivity of Trypanosoma cruzi.

Glycosomes, peroxisome-like organelles in Trypanosoma cruzi, contain enzymes involved in various metabolic processes, including glycolysis. Glycosomal ABC transporters (GATs) play a vital role in maintaining metabolic homeostasis by facilitating metabolite exchange between glycosomes and the cytoplasm. GAT3 is a member of the GAT family, which also includes GAT1 and GAT2. GAT3 transcript levels are downregulated in benznidazole-resistant T. cruzi populations; however, its specific functions remain unknown. Therefore, in this study, we generated GAT3 single-knockout and null mutant lines of the T. cruzi Dm28c strain using the CRISPR/Cas9 system to investigate GAT3 roles in parasite biology. RT-qPCR revealed increased GAT2 transcript levels in the GAT3 null mutant line, without any changes in GAT1 levels. Our findings suggest that GAT3 is not essential for T. cruzi survival, as null mutant parasites showed no growth difference compared to the Cas9-expressing controls. Moreover, the GAT3 single-knockout line exhibited increased resistance to benznidazole, whereas the null mutant line exhibited benznidazole susceptibility similar to the control. Furthermore, both GAT3 single-knockout and null mutant lines showed increased tolerance to hydrogen peroxide-induced oxidative stress. In vitro infection assay of L929 murine fibroblasts revealed that the GAT3 null parasites exhibited a significantly lower infection rate and fewer intracellular amastigotes than the controls. Overall, GAT3 is crucial for T. cruzi infectivity and the regulation of oxidative stress responses, playing key roles in the metabolic regulation and pathogenicity of this parasite.