Fig. 4.
Degradation of the ER by PROTACs is proteasome-dependent and E3 ligase recognition residue-dependent. A. PROTAC-mediated ER degradation is inhibited in a dose-dependent manner by the general proteasome inhibitor, epoxomicin. B. The hydroxyproline residue is critical for pVHL recognition of the PROTAC, as a mutant containing norleucine (17) is unable to degrade the ER. C. Immunofluorescence data supporting the western blotting results of A and B. Epoxomicin causes the accumulation of the ER (green), while 17 does not cause ER degradation when compared to controls. Blue staining (DAPI) indicates the nucleus.
