Novel functions of Trypanosoma cruzi NDPK on parasite DNA integrity

SAYE, MELISA; DI GIROLAMO, FABIO; REIGADA, CHANTAL; VALERA-VERA, EDWARD; PEREIRA, CA; MIRANDA, MARIANA

Mar del Plata

Congreso; Reunión Anual de Sociedades de Biociencia; 2019

Nucleoside diphosphate kinases (NDPK) are housekeeping enzymes that maintain the intracellular pools of di and tri phosphate nucleotides. These are multifunctional enzymes which are involved in diverse processes, such as signal transduction and DNA repair, among others. TcNDPK1 is a canonical NDPK of Trypanosoma cruzi, the parasite that causes Chagas disease. Several evidences associate TcNDPK1 with DNA-processing mechanisms, for example, the in vitro ability of binding nucleic acids and nuclease activity. In the present work we evaluate the role of TcNDPK1 in DNA-damage responses using heterologous gene expression systems and over-expression in epimastigote cells. We found that different strains of bacteria, WT and ndk- mutants, expressing the enzyme decreased about 5 folds and 18 folds the spontaneous mutation rate, respectively. In addition, yeasts lacking the endogenous gene YNK1 (YNK1-) and expressing TcNDPK1, were significantly more resistant to 10 mM and 25 mM hydrogen peroxide and were less sensible to UV irradiation than controls. Parasites over-expressing TcNDPK1 were able to withstand different genotoxic stresses caused by hydrogen peroxide, phleomycin and hidroxyurea, being statistically more resistant than control at different concentrations. In addition, under oxidative damage, over-expressing parasites presented lesser genomic damage assessed by agarose gel electrophoresis and augmented levels of PARP, an enzyme involved in the DNA repair machinery. Furthermore, TcNDPK1 was found to have nuclear, peri-nuclear and cytosolic localization. These results strongly suggest that TcNDPK1 is involved in the maintenance of parasite genomic-DNA integrity, thus, giving rise to a novel function.