Skip to main content
. Author manuscript; available in PMC: 2015 May 1.
Published in final edited form as: Curr Opin Hematol. 2014 May;21(3):172–178. doi: 10.1097/MOH.0000000000000030

Fig. 2. Up-regulation of the translation of ATF4 mRNA by eIF2αP upon stress.

Fig. 2

In the 5’UTR of ATF4 mRNA, there are two uORFs that are preferentially translated under non-stressed conditions and prevent the downstream translational initiation at the coding sequence of ATF4 mRNA. As initiating 40S ribosomal subunits scan from the cap structure, translation starts at the uORF1. After termination of translation, the 40S subunit remains associated with mRNA and reinitiates efficiently at uORF2 under non-stressed conditions. Upon stress, elevated eIF2αP impairs the reinitiation of 40S at uORF2 due to limiting functional eIF2. Thus, 40S continues to scan downstream and initiates at the AUG codon of coding sequence of ATF4 mRNA permitting the synthesis of ATF4 protein.