Inducing Ubiquitylation and Protein Degradation as a Drug Development Strategy.

A new drug discovery strategy by inducing the degradation of oncoproteins through ubiquitin-proteasome system (UPS) has gained a lot of traction in the last decade (Verma et al. Mol Cell 77(3):446-460, 2020; Huang, Dixit. Cell Res 26:484, 2016). Multiple degrader platforms, such as IMiDs (Kronke et al. Science 343:301-305, 2014; Lu et al. Science 343:305-309; 2014), PROTAC (proteolysis targeting chimera) (Winter et al. Science 348:1376-1381, 2015), and molecular glues (Tan et al. Nature 446:640-645, 2007), have been approved or currently being developed in clinical trials. Compared to conventional drug inhibitors, degraders have a lot of advantages, such as catalytic mechanisms of action (MOA), no requirement of high-affinity ligands with targets, and potentially more sustained efficacy (Verma et al. Mol Cell 77(3):446-460, 2020; Huang, Dixit. Cell Res 26:484, 2016; Bondeson et al. Nat Chem Biol 11:611-617). Here, we describe protocols that measure intrinsic protein ubiquitination, degrader-induced target protein degradation, and cancer cell proliferation evaluation, as these protocols can help evaluate the potential of a drug target using a degrader platform.