12th International Conference of Pharmaceutical Sciences

Actin-depolymerizing factor (ADF) and cofilin belong to a family (ADF/cofilins) of actin-binding proteins that have their activity regulated by oxidation. In mammalian cells, ADF/cofilins were shown to modulate oxidation-induced programmed cell death. In protozoans, including the apicomplexan parasite Neospora caninum, the regulation of ADF/cofilins by oxidation has not been studied so far and may unveil important mechanisms related to cell proliferation and survival. Based on that, our goal was to investigate if recombinant ADF of N. caninum (NcADF) is oxidized by N-chlorotaurine. NcADF has 3 methionines and 4 cysteines (cys). The recombinant NcADF was treated with N-chlorotaurine and H2O2, forming dimers at higher concentrations of the oxidants. The oxidation of NcADF cys was detected by iodoacetamide-biotin western blotting and confirmed by Ellman’s reagent. After treatment with H2O2, the localization of NcADF was changed, compared to control. As conclusion, NcADF may act as a reduction-oxidation sensor in N. caninum tachyzoites.