STUDYING THE ROLE OF NUCLEOSIDE DIPHOSPHATE KINASE 1 FROM Trypanosoma cruzi IN DNA INVOLVING MECHANISMS

CHANTAL REIGADA; MARIANA R MIRANDA; MELISA M SAYÉ; DI GIROLAMO, FABIO AUGUSTO; CLAUDIO A PEREIRA

CABA

Congreso; Reunión Conjunta de Sociedades de Biociencias (XXIX Reunión de la Sociedad Argentina de Protozoología); 2017

Sociedad Argentina de Protozoología

Nucleoside diphosphate kinases are multifunctional enzymes that participate in many cellular processes besides their housekeeping function of maintaining intracellular pools of di and tri phosphate nucleotides. TcNDPK1 is an isoform of the enzyme present in Trypanosoma cruzi, the parasite that causes Chagas Disease. Among the multiple possible functions, several evidences associate TcNDPK1 with DNA processing, for example, the in vitro ability of binding nucleic acids and its nuclease activity. In the present work we evaluate the role of TcNDPK1 in DNA involving processes such as DNA repair using heterologous gene expression systems and over expression in epimastigote cells. We found that bacterias expressing the enzyme decreased five times the spontaneous mutationrate respect to controls, measured by counting rifampicin resistant colonies. In addition, yeasts lacking the endogenous gene YNK1 (YNK1-) but expressing TcNDPK1, grew more efficiently, tolerated high hydrogen peroxide concentrations (IC50 of 21.2mM and 6.3mM respectively) and were less sensible to UV irradiation than control. All these results support a possible role of TcNDPK1 in DNA repairmechanisms; however parasites over expressing the enzyme had an opposite phenotype. We observed a lower growth rate with higher mortality, reaching parasite densities two to three folds lower than control in the stationary phase. In addition, these parasites had augmented expression levels of activated PARP, an enzyme involved in DNA repair machinery, and twofold increased content of ATP. Such observations are in accordance with the generation of DNA damage,what was observed by gel electrophoresis of the genomic DNA. The non-protective behavior in parasites could be caused possibly by the over expression and deregulation of TcNDPK1. Altogether, these results exhibit the complexity of TcNDPK1 operation and strongly suggest its participation in DNA involving processes, giving rise to novel functions.