BioProject

and is the causative agent of sleeping sickness. More...

and is the causative agent of sleeping sickness. Here we performed the first genome-

wide mapping of pseudouridines (Ψs) on the small RNome. The analysis revealed the

presence of 85 Ψs on small nuclear RNAs (snRNA), the highest number reported thus

far. The Ψs were found at sites of RNA-RNA interactions, but strikingly also on RNA-

protein interaction domains. The modifications on the snRNAs are guided by small

nuclear or nucleolar RNAs (sn(o)RNAs) that are localized both within and outside the

nucleolus. A trypanosome protein homologue to WDR79, the binding protein of Cajal-

body RNA (scaRNA), is essential for guiding Ψ on snRNAs, using flexible guiding rules. Silencing of a single sn(o)RNA eliminated the Ψs on both rRNA and snRNA. The

dual functionality enables simultaneous regulation of both the spliceosome and

ribosome while the parasite cycles between the insect and mammalian hosts. The

study proposes that functional flexibility of H/ACA RNA maybe general to guide novel

targets under ambient conditions. Less...