Pseudouridine RNA modifications on small non-coding RNAs in the human pathogen Trypanosoma brucei: Identification and functional implications

Trypanosoma brucei is the causative agent of sleeping sickness and this parasite cycles between an insect and a mammalian host. Here, two genome-wide approaches were applied for mapping pseudouridinylation sites (Psi) on small nucleolar RNA (snoRNA), 7SL RNA, vtRNA and tRNAs. Psi of C/D snoRNA guiding 2-O-methylation were shown to increase the efficiency of the guided modification on its target. Differential levels of Psis on these ncRNAs were found in the two life stages of the parasite. tRNA isoform abundance and Psi modifications were characterized in the two life stages. The differential Psi modification identified here may contribute to regulating gene expression by modulating the function of non-coding (nc)RNA involved in rRNA processing, rRNA modification, protein synthesis and protein translocation during cycling of the parasite between its two hosts.