TcNDPK2, a Trypanosoma cruzi microtubule-associated nucleoside diphosphate kinase.

Nucleoside diphosphate kinases (NDPKs) are enzymes required to preserve the intracellular nucleoside phosphate equilibrium. Trypanosoma cruzi has four putative nucleoside diphosphate kinases with unidentified biological roles and subcellular localization. TcNDPK2 has an N-terminal domain (DM10) with unknown function, which defines a subgroup of NDPKs distributed in a wide variety of organisms. Digitonin extraction demonstrated that this isoform is distributed in detergent soluble and insoluble fractions. Fluorescence microscopy showed that TcNDPK2 alone or fused to GFP was localized in cytoskeleton and flagella. TcNDPK2 was also detected by Western blot in purified polymerized tubulin and flagellar samples. In parasites expressing DM10 fused with GFP, the fluorescence was localized in cytoskeleton and flagellum with an identical pattern to TcNDPK2. This constitutes the first report that could give insights on the role of DM10 domains in NDPKs and also the identification of the first T. cruzi peptide that contains a microtubule association domain.