The silencing domain of GW182 interacts with PABPC1 to promote translational repression and degradation of microRNA targets and is required for target release.

ABSTRACT: GW182 family proteins are essential in animal cells for microRNA (miRNA)-mediated gene silencing, yet the molecular mechanism that allows GW182 to promote translational repression and mRNA decay remains largely unknown. Previous studies showed that while the GW182 N-terminal domain interacts with Argonaute proteins, translational repression and degradation of miRNA targets are promoted by a bipartite silencing domain comprising the GW182 middle and C-terminal regions. Here we show that the GW182 C-terminal region is required for GW182 to release silenced mRNPs; moreover, GW182 dissociates from miRNA targets at a step of silencing downstream of deadenylation, indicating that GW182 is required to initiate but not to maintain silencing. In addition, we show that the GW182 bipartite silencing

SUBMITTER: Zekri L 

PROVIDER: S-EPMC2786699 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature