BONCAT-iTRAQ Labelling Reveals Molecular Markers of Adaptive Responses in Toxoplasma gondii to Pyrimethamine Treatment

We employed a BONCAT-iTRAQ labelling approach to investigate newly synthesised proteins (NSPs) in <i>Toxoplasma gondii</i> subjected to varying concentrations of the antifolate drug pyrimethamine. Our results reveal that numerous NSPs exhibited altered expression levels in response to the drug, with significant upregulation observed at higher concentrations. Key proteins involved in protein synthesis, stress responses, energy metabolism, and cytoskeletal dynamics were identified, indicating that <i>T. gondii</i> undergoes complex adaptive responses to pyrimethamine treatment. While some of the identified pathways reflect a generic stress response, this study provides important molecular markers and mechanistic insights specific to the parasite's adaptation strategies. These findings contribute to understanding how <i>T. gondii</i> modulates its proteome in response to drug-induced stress and lay the groundwork for further investigations into potential therapeutic targets.