Babesia microti Aldo-keto Reductase-Like Protein Involved in Antioxidant and Anti-parasite Response

The intraerythrocytic apicomplexan is the primary causative agent of human babesiosis, which is an infectious disease that occurs in various regions around the world. Although the aldo-keto reductases (AKRs) of this parasite have been sequenced and annotated, their biological properties remain unknown. AKRs are a superfamily of enzymes with diverse functions in the reduction of aldehydes and ketones. In the present study, we cloned the full-length cDNA of a aldo-keto reductase-like protein (BmAKR) and analyzed the deduced amino acid sequence of the BmAKR protein. This protein has a conserved AKR domain with an N-terminal signal sequence. was upregulated on the 8th day after infection, whereas it was downregulated during the later stages. The recombinant protein of BmAKR was expressed in a glutathione -transferase-fused soluble form in Western blot analysis showed that the mouse anti-BmAKR antibody recognized native BmAKR from a parasite lysate. Immunofluorescence microscopy localized BmAKR to the cytoplasm of merozoites in mouse RBCs in this study. expression was significantly upregulated in the presence of oxidant stress. Atovaquone, a known anti-babesiosis drug, and robenidine, a known anti-coccidiosis drug, induced upregulation of mRNA, thereby suggesting that may be involved in anti-parasite drug response.