Seminar

Proximity proteomics for studying ubiquitin-like modifications and rare disease

James D Sutherland

The life and death of proteins underlies the form and function of cells. Understanding how ubiquitin-like modifiers can change the behavior and fate of proteins, and how this can affect organelle function, is challenging. The modifications are often dynamic and form new protein complexes through low-affinity interactions to execute these changes. With over 600 E3 ligases found in the human proteome, targeted protein degradation using these ligases and the ubiquitin-proteasome system is an emerging pharmaceutical strategy, but our knowledge of specific substrates for these ligases is lacking. Targeted in vivo biotinylation techniques allow new possibilities for rapid labeling and robust purification. In this talk, two applications of biotin-based proximity proteomics will be presented. First, we have devised SUMO-ID, a novel technique using proximity biotinylation and proteomics to decipher the consequences of ubiquitin-like modifications. Second, we are developing a new method to identify specific substrates of E3 ligases and to define subcellular ubiquitomes. These methods are powerful and flexible, and should find applications in many different research areas.