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Genome-wide identification of circRNAs translated by eIF4A3

ABSTRACT: Exon junction complexes (EJCs) deposited on spliced mRNAs play multifunctional roles in the regulation of gene expression. Whereas the formation and components of EJCs are well characterized, the underlying molecular mechanisms for gene regulation remain poorly understood. Here we find that a eukaryotic translation initiation factor (eIF) 4A3, a core component of EJC directly interacts with eIF3g, a subunit of eIF3 complex. This interaction serves as a linker between the EJC and eIF3 complex, consequently driving an internal ribosomal recruitment. Accordingly, artificially tethered EJC component or cellular EJC deposited on mRNA after splicing promotes internal initiation of translation in a way that is resistant to cellular stress induced by serum starvation. We also demonstrate that translatable endogenous or reporter circular RNAs depend on EJC for their association with polysomes. Our results uncover an internal initiation driven by EJC, expanding the protein-coding potential of human transcriptome including circular RNAs.

ORGANISM(S): Homo sapiens

PROVIDER: GSE131563 | GEO | 2023/08/31

REPOSITORIES: GEO

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