Fig. 4. CPX I expression is efficiently silenced by plasmids directing the synthesis of small interfering RNAs (siRNA). Oligonucleotides were synthesized to specifically target CPX I and were cloned into pSUPER vector (see Material and Methods). The efficiency of siRNA was assessed by cotransfection of GFP-CPX I in the presence or in the absence of siRNA CPX I in INS1 cells. CPX I expression was detected using anti-GFP antibody. The western blot shows ectopic expression of CPX I, in the absence of siRNA CPX I (–) and in the presence of empty vector pSUPER (control) compared to untransfected cells (NT). However, CPX I expression is suppressed by adding siRNA CPX I.