UbiquiEnaEon is one of the most common post-translaEonal modificaEons and regulates virtually all aspects of eukaryoEc biology including proteostasis, autophagy, cell signalling, protein trafficking and cell death. It has recently been demonstrated that ubiquiEn can be aXached to non-protein substrates. UbiquiEn may be added to the C6-hydroxyl group of glucose and the 3’- hydroxyl group of single-stranded DNA and RNA in vitro. UbiquiEnaEon of lipids has also been shown in cellulo to play important roles in control of infecEon, xenophagy and endocyEc trafficking. UbiquiEn can be aXached to the outer membrane of invading Salmonella via the lipid A moiety of lipopolysaccharide (LPS) by the E3 ligase, RNF213. Furthermore, aXachment of ubiquiEn to phosphaEdylethanolamine (PE) in endosomes and lysosomes suggests ubiquiEnaEon of lipids is likely far more widespread than currently understood. However, the breadth and significance of this new form of cellular signalling remains limited by a lack of tools to detect it.
The Komander group has developed a sensiEve, mass spectrometry-based approach to idenEfy non-proteinaceous ubiquiEnaEon events within cells and Essues. We are adapEng this workflow to assess lipid ubiquiEnaEon in vitro and in cells. UElising ubiquiEnated phospholipids generated in vitro we could successfully detect ubiquiEnated-PE via this approach. Now, we intend to apply this method to fully grasp the unexplored roles of lipid ubiquiEnaEon in cell intrinsic pathways.