Protocol to identify E3 ligases amenable to biodegraders using a cell-based screening.

Here, we provide a protocol for the identification of E3 ubiquitin ligases that are functional when implemented as biodegraders using a cell-based screening assay. We describe steps for establishing a stable cell line expressing a GFP-tagged protein of interest (POI), preparing a sub-library of E3 ligases to screen, and performing the cell-based screening. This protocol can be broadly applied to identify any functional E3 ligase in a biodegrader setting.

Discovery of SOCS7 as a versatile E3 ligase for protein-based degraders.

Targeted protein degradation (TPD) strategy harnesses the ubiquitin-proteasome system (UPS) to degrade a protein of interest (POI) by bringing it into proximity with an E3 ubiquitin ligase. However, the limited availability of functional E3 ligases and the emergence of resistance through mutations in UPS components restrict this approach. Therefore, identifying alternative E3 ligases suitable for TPD is important to develop new degraders and overcome potential resistance mechanisms.