Quantitative analysis of MDCK cells after siRNA treatment. (A) Quantification of Kapβ1 silencing in MDCK cells after treatment with Kapβ1-specific siRNA1 or siRNA2 at the amounts shown. The dashed line indicates the removal of unrelated sample lanes that were probed on the same membrane. (B) Proteomic analysis of Kapβ1, CRM1, and Imp5 cellular abundance before and after Kapβ1 silencing. Only Kapβ1 was significantly reduced in MDCK cells, whereas CRM1 and Imp5 levels were not affected. All data points were normalized to the mean value of Kapβ1 abundance in control siRNA cells (n = 4). (C) Analysis of CRM1 silencing efficiency in MDCK cells after treatment with CRM1-specific siRNA. See Materials and methods for details. Note: In all cases, the chemiluminescent signal was recorded using different exposure times to optimally visualize GAPDH or a given Kap. CRM1 and Kapβ1 signals were normalized to the corresponding GAPDH signal from the same lane. MW, molecular weight; M, marker. Source data are available for this figure: SourceData FS4.