EIF4A2 drives repression of translation at initiation by Ccr4-Not through purine-rich motifs in the 5’UTR.

ABSTRACT: Regulation of the mRNA life-cycle is central to gene expression control and determination of cell fate. miRNAs represent a critical mRNA regulatory mechanism, but despite decades of research, their mode of action is still not fully understood. Here we show eIF4A2 is a major effector of the repressive miRNA pathway functioning via the Ccr4-Not complex. We demonstrate that while DDX6 interacts with Ccr4-Not, its effects in the mechanism are not as pronounced. Through its interaction with the Ccr4-Not complex eIF4A2 represses mRNAs at translation initiation. We show evidence that native eIF4A2 has similar properties to chemically inhibited eIF4A1. We demonstrate that eIF4A2 exerts it repressive effect by binding purine-rich motifs which are enriched in the 5’UTR directly upstream of the AUG start codon. The data supports a model whereby purine motifs towards the 3’ end of the 5’UTR are associated with increased ribosome occupancy and possible uORF activation similar to that observed for mRNAs affected by inhibited eIF4A1.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Permanent Cell Line Cell

DISEASE(S): Disease Free

SUBMITTER: Kelly Hodge  

LAB HEAD: Sara Rossana Zanivan

PROVIDER: PXD014764 | Pride | 2019-10-08

REPOSITORIES: Pride