The RNA methyltransferase NSUN5 modulates the lifespans of yeast, worms and flies by re-programming the translation of specific subsets of mRNAs, which are associated with the cellular stress response. Here we show by RNA bisulfite sequencing that Rcm1 specifically methylates C2278 of yeast 25S rRNA and nsun-5 C3381 of C. elegans 28S rRNA. Overall design: In S. cerevisiae RNA was isolated from polysome and monosome fractions of two genotypes (wild-type and rcm1 deletion) and three stress treatments (unstressed, 30 min and 90 min H2O2) in single replicates. In C. elegans total RNA of wild-type (N2) and JGG1 (nsun-5 mutant) were compared in single replicates.