Cullin-RING ligase BioE3 reveals molecular-glue-induced neosubstrates and rewiring of the endogenous Cereblon ubiquitome.

Background: The specificity of the ubiquitination process is mediated by the E3 ligases. Discriminating genuine substrates of E3s from mere interacting proteins is one of the major challenges in the field. We previously developed BioE3, a biotin-based approach that uses BirA-E3 fusions together with ubiquitin fused to a low-affinity AviTag to obtain a site-specific and proximity-dependent biotinylation of the substrates.