FIGURE 4.

Effect of proteasome inhibition on UCE degradation. TREx-HeLa cells stably expressing F513SfsX113 (A) or WT, R328C, or H84Q UCEs (B) were treated with 120 μg/ml CHX for either 30 or 60 min (A) or 6 or 24 h (B) in the presence or absence of 10 μm MG132. Cell lysates were prepared and subjected to immunoblotting with monoclonal anti-HA Ab. Either 50 μg (A) or 5 μg (B) of cell lysates was used for the immunoblots. In C, aliquots of cell lysates from the 24-h CHX samples were incubated with or without 1,000 units of PNGase F overnight at 37 °C, followed by SDS-PAGE and Western blot analysis.