Pseudouridine profiling reveals widespread regulated mRNA pseudouridylation in yeast and human cells

We report the development of Pseudo-Seq, a sequencing based technique for identification of pseuoduridine (Ψ) modifications within RNA. We performed Pseudo-Seq on S. cerevisiae and HeLa cells and find the first evidence for pseusouridylation of endogenous mRNAs. RNA was treated with CMC to modify Ψ residues, which cause RT stops. The sites of CMC-dependent RT stops were used to identify sites of pseudouridyation.