title: RNA interference, growth and differentiation appear normal in African trypanosomes lacking Tudor staphylococcal nuclease.
abstract: Ribonucleases play important roles in the RNA interference (RNAi) pathway. The Dicer endonuclease converts double-stranded (ds)RNA into small interfering (si)RNA and the Slicer endonuclease, as a component of the RNA induced silencing complex (RISC), cleaves mRNA. Tudor staphylococcal nuclease (Tudor-SN) is another component of RISC in humans, flies and nematodes and is therefore implicated in the RNAi pathway. Here, we explore the potential role of African trypanosome Tudor-SN in RNAi. First, we assembled tudor-sn null mutants and showed that the gene is dispensable for normal growth and for differentiation. Next, we developed an inducible RNAi reporter system and demonstrated that Tudor-SN is dispensable for RNAi. The kinetics of mRNA knock-down, protein knock-down and protein recovery following inactivation of dsRNA expression are all unperturbed in the absence of Tudor-SN. We conclude that if this nuclease plays a role in the destruction or processing of dsRNA, mRNA or siRNA in the RNAi pathway, it is likely a minor one.
authors.affiliation: London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
authors.forename: Sam
authors.initials: S
authors.lastname: Alsford
authors.forename: Louise E
authors.initials: LE
authors.lastname: Kemp
authors.forename: Taemi
authors.initials: T
authors.lastname: Kawahara
authors.forename: David
authors.initials: D
authors.lastname: Horn
mesh_terms: D017353:Gene Deletion; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D008836:Micrococcal Nuclease / Q000172:deficiency* / Q000502:physiology*; D015800:Protozoan Proteins / Q000235:genetics / Q000502:physiology; D034622:RNA Interference; D014345:Trypanosoma / Q000201:enzymology* / Q000254:growth & development*
chemical_list: D015800:Protozoan Proteins; D008836:Micrococcal Nuclease