tRNA modification reprogramming contributes to artemisinin resistance in Plasmodium falciparum.

Plasmodium falciparum artemisinin (ART) resistance is driven by mutations in kelch-like protein 13 (PfK13). Quiescence, a key aspect of resistance, may also be regulated by a yet unidentified epigenetic pathway. Transfer RNA modification reprogramming and codon bias translation is a conserved epitranscriptomic translational control mechanism that allows cells to rapidly respond to stress. We report a role for this mechanism in ART-resistant parasites by combining tRNA modification, proteomic and codon usage analyses in ring-stage ART-sensitive and ART-resistant parasites in response to drug. Post-drug, ART-resistant parasites differentially hypomodify mcm5s2U on tRNA and possess a subset of proteins, including PfK13, that are regulated by Lys codon-biased translation. Conditional knockdown of the terminal s2U thiouridylase, PfMnmA, in an ART-sensitive parasite background led to increased ART survival, suggesting that hypomodification can alter the parasite ART response. This study describes an epitranscriptomic pathway via tRNA s2U reprogramming that ART-resistant parasites may employ to survive ART-induced stress.