The ubiquitin conjugase Rad6 mediates ribosome pausing during oxidative stress

• Published in: Cell reports (Cambridge) Vol. 42; no. 11; p. 113359
• Main Authors: Meydan, Sezen, Barros, Géssica C., Simões, Vanessa, Harley, Lana, Cizubu, Blanche K., Guydosh, Nicholas R., Silva, Gustavo M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 28.11.2023; Elsevier
• Subjects: CP: Molecular biology; gamma-Glutamyl Hydrolase - metabolism; Oxidative Stress; Rad6; ribosome pause; ribosome ubiquitination; Ribosomes - metabolism; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - metabolism; stress response; translation control; Ubiquitin - metabolism; ribosome pause; stress response; Rad6; CP: Molecular biology; translation control; oxidative stress; ribosome ubiquitination
• DOI: 10.1016/j.celrep.2023.113359
• ISSN: 2211-1247

Oxidative stress causes K63-linked ubiquitination of ribosomes by the E2 ubiquitin conjugase Rad6. How Rad6-mediated ubiquitination of ribosomes affects translation, however, is unclear. We therefore perform Ribo-seq and Disome-seq in Saccharomyces cerevisiae and show that oxidative stress causes ribosome pausing at specific amino acid motifs, which also leads to ribosome collisions. However, these redox-pausing signatures are lost in the absence of Rad6 and do not depend on the ribosome-associated quality control (RQC) pathway. We also show that Rad6 is needed to inhibit overall translation in response to oxidative stress and that its deletion leads to increased expression of antioxidant genes. Finally, we observe that the lack of Rad6 leads to changes during translation that affect activation of the integrated stress response (ISR) pathway. Our results provide a high-resolution picture of the gene expression changes during oxidative stress and unravel an additional stress response pathway affecting translation elongation. [Display omitted] •Rad6 is required for sequence-specific ribosome pausing under oxidative stress•Rad6 affects translation independently of the ribosome-associated quality-control pathway•Cells lacking Rad6 show dysregulated translational repression upon oxidative stress•Loss of Rad6 leads to altered activation of the integrated stress response pathway Meydan et al. find a mechanism of translation control mediated by the ubiquitin conjugase Rad6. During oxidative stress, elongating ribosomes pause while making Ile-Pro peptide bonds, and the absence of Rad6 leads to non-canonical reprogramming of translation, implicating Rad6 as a regulator of the stress response.