RT Journal Article
SR Electronic
T1 Site-specific K63 ubiquitinomics reveals post-initiation regulation of ribosomes under oxidative stress
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 392076
DO 10.1101/392076
A1 Songhee Back
A1 Christine Vogel
A1 Gustavo M. Silva
YR 2018
UL http://biorxiv.org/content/early/2018/08/14/392076.abstract
AB During oxidative stress, K63-linked polyubiquitin chains accumulate in the cell and modify a variety of proteins including ribosomes. Knowledge of the precise sites of K63 ubiquitin is key to understanding its function during the response to stress. To identify the sites of K63 ubiquitin, we developed a new mass-spectrometry based method that quantified >1,100 K63 ubiquitination sites in yeast responding to oxidative stress induced by H2O2. We determined that under stress, K63 ubiquitin modified proteins involved in several cellular functions including ion transport, protein trafficking, and translation. The most abundant ubiquitination sites localized to the head of the 40S subunit of the ribosome, modified assembled polysomes, and affected the binding of translation factors. The results suggested a new pathway of post-initiation control of translation during oxidative stress and illustrated the importance of high-resolution mapping of noncanonical ubiquitination events.