Efficient and Accurate Translation Initiation Directed by TISU Involves RPS3 and RPS10e Binding and Differential Eukaryotic Initiation Factor 1A Regulation.

ABSTRACT: Canonical translation initiation involves ribosomal scanning, but short 5' untranslated region (5'UTR) mRNAs are translated in a scanning-independent manner. The extent and mechanism of scanning-independent translation are not fully understood. Here we report that short 5'UTR mRNAs constitute a substantial fraction of the translatome. Short 5'UTR mRNAs are enriched with TISU (translation initiator of short 5'UTR), a 12-nucleotide element directing efficient scanning-independent translation. Comprehensive mutagenesis revealed that each AUG codon-flanking nucleotide of TISU contributes to translational strength, but only a few are important for accuracy. Using site-specific UV cross-linking of ribosomal complexes assembled on TISU mRNA, we demonstrate specific binding of TISU to ribosomal pr

SUBMITTER: Haimov O 

PROVIDER: S-EPMC5514451 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature