Trypanosoma brucei RNA editing: coupled cycles of U deletion reveal processive activity of the editing complex. Academic Article uri icon


  • RNA editing in Trypanosoma brucei is posttranscriptional uridylate removal/addition, generally at vast numbers of pre-mRNA sites, but to date, only single editing cycles have been examined in vitro. We here demonstrate achieving sequential cycles of U deletion in vitro, with editing products confirmed by sequence analysis. Notably, the subsequent editing cycle is much more efficient and occurs far more rapidly than single editing cycles; plus, it has different recognition requirements. This indicates that the editing complex acts in a concerted manner and does not dissociate from the RNA substrate between these cycles. Furthermore, the multicycle substrate exhibits editing that is unexpected from a strictly 3'-to-5' progression, reminiscent of the unexpected editing that has been shown to occur frequently in T. brucei mRNAs edited in vivo. This unexpected editing is most likely due to alternate mRNA:guide RNA (gRNA) alignment forming a hyphenated anchor; its having only a 2-bp proximal duplex helps explain the prevalence of unexpected editing in vivo. Such unexpected editing was not previously reported in vitro, presumably because the common use of artificially tight mRNA:gRNA base pairing precludes alternate alignments. The multicycle editing and unexpected editing presented in this paper bring in vitro reactions closer to reproducing the in vivo editing process.

published proceedings

  • Mol Cell Biol

author list (cited authors)

  • Alatortsev, V. S., Cruz-Reyes, J., Zhelonkina, A. G., & Sollner-Webb, B.

citation count

  • 18

complete list of authors

  • Alatortsev, Vadim S||Cruz-Reyes, Jorge||Zhelonkina, Alevtina G||Sollner-Webb, Barbara

publication date

  • April 2008