Effect of proteasome inhibitor – bortezomib on ATB0,+ level. (A) HEK293 cells were transfected for 48 h with p3xFLAG-CMV14/B0,+ vector (B0,+) and, where indicated with 9-fold excess of SEC24C-VN and an indicated concentration of bortezomib. (B) Cells were stably transfected either with p3xFLAG-CMV14 (V) or with p3xFLAG-CMV14/B0,+ (B0,+) and SEC24C-VN and bortezomib were added where indicated for the last 48 h. (C) MCF7 cells were incubated for 48 h with indicated concentration of bortezomib. In (A) and (B) ATB0,+ was detected with anti-FLAG antibodies, in (C) with anti-ATB0,+ antibodies. GAPDH was detected, as loading control.