A Ribonuclease Coordinates siRNA Amplification and mRNA Cleavage during RNAi

ABSTRACT: Effective silencing by RNA-interference (RNAi) depends on mechanisms that amplify and propagate the silencing signal. In some organisms, small-interfering (si) RNAs are amplified from target mRNAs by RNA-dependent RNA polymerase (RdRP). Both RdRP recruitment and mRNA silencing require Argonaute proteins, which are generally thought to degrade RNAi targets by directly cleaving them. However in C. elegans, the enzymatic activity of the primary Argonaute, RDE-1, is not required for silencing activity. We show that RDE-1 can instead recruit an endoribonuclease, RDE-8, to target RNA. RDE-8 can cleave RNA in vitro and is needed for the production of 3′ uridylated fragments of target mRNA in vivo. We also find that RDE-8 promotes RdRP activity, thereby ensuring amplification of siRNAs. Togeth

ORGANISM(S): Caenorhabditis elegans

SUBMITTER: Hsin-yue Tsai 

PROVIDER: E-GEOD-59300 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress