Trypanosoma cruzi modulates its histone post-translational modifications under nutritional stress

Introduction Histone post-translational modifications (hPTMs) constitute one of the main regulatory mechanisms of chromatin state in eukaryotes. The presence of different hPTMs has been described in Trypanosoma cruzi ; however, their roles in parasite biology and adaptation to environmental changes remain poorly understood. The nutritional stress faced by the parasite in the intestine of the invertebrate host triggers differentiation of non-infective epimastigotes into infective metacyclic trypomastigotes. Methods The modulation of hPTMs in epimastigotes subjected to short- and long-term nutritional stress was analyzed using a bottom-up proteomic workflow based on propionic anhydride derivatization and a combination of complementary mass spectrometry-based proteomic approaches (LC-MS/MS and GeLC-MS/MS) with label-free quantification. Results A total of 172 hPTMs were identified. Monomethylation and acetylation were the most abundant hPTM classes in all conditions, whereas dimethylation, trimethylation, and crotonylation showed significant changes under more prolonged nutritional stress. Among the identified modifications, 20 hPTM marks distributed across 16 histone peptides were differentially modulated across conditions, with most changes observed during prolonged nutritional stress. Notably, N-terminal acetylation of H2A.Z (K42–K58) increased significantly as nutrient availability decreased over time. Discussion These results show that T. cruzi dynamically modulates its hPTM landscape in response to nutrient limitation.