Characterisation of TcFUT1, a mitochondrial fucosyltransferase from Trypanosoma cruzi

Previous work has shown that the TbFUT1 and LmjFUT1 genes encode essential fucosyltransferases located inside the single mitochondria of the protozoan parasites Trypanosoma brucei and Leishmania major, respectively. However, nothing was known about the orthologous gene TcFUT1 or its gene product in Trypanosoma cruzi, aetiological agent of Chagas disease. In this study, we describe the overexpression of TcFUT1 with a C-terminal 6xMyc epitope tag in T. cruzi epimastigote cells. Overexpressed and immunoprecipitated TcFUT1-6xMyc was used to demonstrate enzymatic activity and to explore substrate specificity. This defined TcFUT1 as a GDP-Fuc : βGal α1-2 fucosyltransferase with a strict requirement for acceptor glycans with non-reducing terminal Galβ1-3GlcNAc structures. This differs from the specificity of the T. brucei orthologue TbFUT1, which can also tolerate non-reducing terminal Galβ1-4GlcNAc and Galβ1-4Glc acceptor sites. Immunofluorescence microscopy using α-Myc tag antibodies also showed a mitochondrial location for TcFUT1 in T. cruzi epimastigote cells. Collectively, these results are like those described for TbFUT1 and LmjFUT1 from T. brucei and L. major, suggesting that FUT1 gene products have conserved function for across the trypanosomatids and may share therapeutic target potential.