Authors

E Dueñas¹; N Kraeva¹; V Yurchenko¹;  ¹ Life Science Research Centre, Faculty of Science, University of Ostrava, Czechia

Discussion

Base J is a unique modified DNA base β-D-glucosyl-hydroxymethyluracil) found in the nuclear genomes of trypanosomatids, Euglena, and Diplonema. It replaces around 1% of thymidines. Base J biosynthesis occurs in two steps: first, the J-binding proteins JBP1/JBP2 hydroxylate thymidine residues to form 5-hydroxymethyluracil (hmU); second, hmU is glucosylated by a specific J-glucosyltransferase (J-GT) to generate base J. Base J has been implicated in transcription termination, telomere maintenance, and presumably metacyclogenesis. Previously, we demonstrated that inhibition of JBP1/JBP2 thymidine hydroxylase activity by dimethyloxalylglycine (DMOG) reduces base J levels in Leishmania mexicana genome, leading to the arrest at the metacyclic stage and impaired in vitro differentiation into axenic amastigotes. Ablation of the J-GT gene in Trypanosoma brucei causes a complete loss of base J. In this study, we generated a J-GT null mutant in L. mexicana using CRISPR/Cas9 technology to investigate the effect of the complete loss of the J base on parasite differentiation and infectivity.