Quality control and signaling pathways at stalled ribosomes

Aberrant mRNAs can arise from errors in RNA processing or from various physicochemical insults. Ribosomes translating such faulty mRNAs may stall, producing incomplete and potentially toxic polypeptides. These aberrant translation products are eliminated by the ribosome-associated quality control pathway. Ribosome stalling also leads to ribosome collisions, which can activate signaling pathways that enable cells to adapt to stress or determine cell fate. Here, in this Review, we summarize the molecular mechanisms of ribosome stalling and the associated quality control and signaling pathways, and discuss their implications in disease and therapeutics.