Related Experiment Video
Updated: Jul 23, 2025

Toeprinting Analysis of Translation Initiation Complex Formation on Mammalian mRNAs
Published on: May 10, 2018
Translational regulation by uORFs and start codon selection stringency
Thomas E Dever1, Ivaylo P Ivanov1, Alan G Hinnebusch1
1Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA thomas.dever@nih.gov ivaylo.ivanov@nih.gov ahinnebusch@nih.gov.
Abstract:
In addition to the main, protein-coding, open reading frame (mORF), many eukaryotic mRNAs contain upstream ORFs (uORFs) initiated at AUG or near-cognate codons residing 5' of the mORF start site. Whereas translation of uORFs generally represses translation of the mORFs, a subset of uORFs serves as a nexus for regulating translation of the mORF. In this review, we summarize the mechanisms by which uORFs can repress or stimulate mRNA translation, highlight uORF-mediated translational repression involving ribosome queuing, and critically evaluate recently described alternatives to the delayed reinitiation model for uORF-mediated regulation of the GCN4/ATF4 mRNAs.
Related Concept Videos
Leaky Scanning
Translational Regulation
Improving Translational Accuracy
Initiation of Translation
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Regulation of Expression at Multiple Steps
Transcriptional Regulation: Riboswitches

