Skip to main content
. 2022 Feb 25;119(9):e2117226119. doi: 10.1073/pnas.2117226119

Fig. 1.

Fig. 1.

A schematic representation of the role of eIF1 and eIF5 in regulating stringency of start codon selection in eukaryotes. (Left) mRNA with the mORF AUG start codon in suboptimal context (mAUG*). (Right) mRNA with inhibitory uORF initiated by an AUG codon in suboptimal context (uAUG*). High levels of eIF1 confer high stringency of start codon selection leading to 1) repressed expression of genes initiated by mAUG* codons and 2) increased leaky scanning of uAUG* codons resulting in the derepression of mORF translation. Low stringency of start codon selection in cells with high levels of eIF5 has the opposite effects, stimulating translation of ORFs starting with mAUG* and repressing the translation of the mORF on mRNAs with inhibitory uORFs initiating at uAUG* codons.