Figure 3.

ATR is a degradation substrate of E3 ubiquitin ligase FBXO32. (A) Western blot analysis of whole cell lysates of PANC-1 cells transfected with the indicated constructs. Cells were treated with or without 20 µM of MG132 for 8 h before harvest. (B) Quantification of protein levels of ATR in PANC-1 cells. (C) PANC-1 cells were transfected with indicated plasmids for 48 h followed by treatment with 20 µM MG132 for 8 h. Immunoprecipitated Flag-ATR proteins were analyzed by western blot analysis for ubiquitination. FBXO32, F-Box protein 32; DMSO, dimethyl sulfoxide; HA, hemagglutinin; Ub, ubiquitin; IB, immunoblot; IP, immunoprecipitation.