Figure EV5. Model for the nutrient‐dependent control of Acc1p levels mediated by the uORF .

1. Top: In rich media with high ribosome content, the uORF does not significantly inhibit the number of scanning ribosomes that initiate from the main ACC1 ORF. Bottom: In poor media with lower ribosome content, the uORF reduces the number of scanning ribosomes that are able to reach the main, downstream AUG, thereby disproportionately reducing Acc1p synthesis.
2. The expected translational efficiency of the wild‐type ACC1 mRNA (shown in black) and the mutant lacking the uORF (shown in red) is depicted as a function of the concentration of active initiating ribosomes, R*, in the cell, adapted from the standard theoretical calculations of Lodish (1974).