Yeast ubiquitinomics -- cellular signaling during oxidative stress

Protein ubiquitination is an important modification with a variety of cellular functions. These functions are determined by the lysine through which polyubiquitin chains are linked. While K48 polyubiquitination is most abundant and well-studied, much less is known about K63 chains that occur frequently in the cell. Ongoing studies in our lab investigate the roles of both K48 and K63 polyubiquitination. Using a combination of large-scale methods and targeted screens we identified a new role for K63 polyubiquitination under peroxide stress. We identified both the ubiquitinating and deubiquitinating enzymes, as well as a set of target proteins which suggest a role of K63 polyubiquitination in translation regulation.