A Link Between mRNA Turnover and RNA Interference in Arabidopsis
2004; American Association for the Advancement of Science; Volume: 306; Issue: 5698 Linguagem: Inglês
10.1126/science.1101092
ISSN1095-9203
AutoresSilvia Eleonora Gazzani, Tom Lawrenson, Claire Woodward, Denis J. Headon, Robert Sablowski,
Tópico(s)RNA Research and Splicing
ResumoIn RNA interference (RNAi), double-stranded RNA (dsRNA) triggers degradation of homologous messenger RNA. In many organisms, RNA-dependent RNA polymerase (RdRp) is required to initiate or amplify RNAi, but the substrate for dsRNA synthesis in vivo is not known. Here, we show that RdRp-dependent transgene silencing in Arabidopsis was caused by mutation of XRN4, which is a ribonuclease (RNase) implicated in mRNA turnover by means of decapping and 5'-3' exonucleolysis. When both XRN4 and the RdRp were mutated, the plants accumulated decapped transgene mRNA. We propose that mRNAs lacking a cap structure become exposed to RdRp to initiate or maintain RNAi.
Referência(s)