Authors

Discussion

DYRKs comprise a family of pro-survival eukaryotic protein kinases against stress and differentiation stimuli. For combating leishmaniasis, a serious disease caused by the protozoan parasite Leishmania, it is essential to increase the validated drug target repertoire. To this end we have selected a member of the Leishmania DYRK family, L. infantum (Lin) DYRK1, for probing its druggability potential. We employed a facilitated null mutant analysis in promastigotes that ectopically express DYRK1 from a plasmid that carries a negative selection marker, and a GFP reporter. Episomal persistence in logarithmic promastigotes after 15 passages under negative selection was used as a readout of essentiality. Our results showed that episome loss was tolerated in logarithmic parasites, suggesting that LinDYRK1 deletion could be compensated. However, early stationary phase LinDYRK1-/- promastigotes displayed a round morphology, mitotic arrest, and subsequent parasite death. Moreover, LinDYRK1-/- parasites showed both reduced thermotolerance to heat-shock, a signal required for stage differentiation, and reduced intracellular survival. Over-expression of LinDYRK1 resulted in G1 cell-cycle phase prolongation. Overall our results suggest that LinDYRK1 is an important pro-survival kinase in stationary growth phase and parasite differentiation, and thus a potential drug target for the prophylaxis against leishmaniasis.