AI Article Synopsis
- Ribosome movement during protein synthesis can encounter pauses, and several questions remain about their locations, triggers, and significance.
- This study examines ribosome collisions (disomes) in humans and zebrafish and identifies specific motifs and regions where these pauses occur.
- Findings reveal that certain sequences can lead to ribosome collisions, with implications for protein quality control and the role of ribosomes in managing ER stress response factors like XBP1u.
Article Abstract
Ribosome movement is not always smooth and is rather often impeded. For ribosome pauses, fundamental issues remain to be addressed, including where ribosomes pause on mRNAs, what kind of RNA/amino acid sequence causes this pause, and the physiological significance of this attenuation of protein synthesis. Here, we survey the positions of ribosome collisions caused by ribosome pauses in humans and zebrafish using modified ribosome profiling. Collided ribosomes, i.e., disomes, emerge at various sites: Pro-Pro/Gly/Asp motifs; Arg-X-Lys motifs; stop codons; and 3' untranslated regions. The electrostatic interaction between the charged nascent chain and the ribosome exit tunnel determines the eIF5A-mediated disome rescue at the Pro-Pro sites. In particular, XBP1u, a precursor of endoplasmic reticulum (ER)-stress-responsive transcription factor, shows striking queues of collided ribosomes and thus acts as a degradation substrate by ribosome-associated quality control. Our results provide insight into the causes and consequences of ribosome pause by dissecting collided ribosomes.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7746506 | PMC |
| http://dx.doi.org/10.1016/j.celrep.2020.107610 | DOI Listing |
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