Activation of a microRNA response in trans reveals a new role for poly(A) in translational repression.

ABSTRACT: Here, we report that the untreated rabbit reticulocyte lysate contains over 300 different endogenous microRNAs together with the major components of the RNA-induced silencing complex and thus can be used as a model in vitro system to study the effects of microRNAs on gene expression. By using this system, we were able to show that microRNA hybridization to its target resulted in a very rapid and strong inhibition of expression that was exerted exclusively at the level of translation initiation with no involvement of transcript degradation or deadenylation. Moreover, we demonstrate that the magnitude of microRNA-induced repression can only be recapitulated in the context of a competitive translating environment. By using a wide spectrum of competitor cellular and viral RNAs, we could furthe

SUBMITTER: Ricci EP 

PROVIDER: S-EPMC3130266 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature