FIGURE 7.

Effect of siRNA-mediated CPSF1 knockdown on exon 6 inclusion of minigenes sub(36–40) and sub(36–40)pAmut. (A) CPSF1 was depleted by three different siRNAs. A nonsilencing (Qiagen AllStars) siRNA served as control. siRNAs were transfected into HeLa cells, followed by minigene transfection 48 h later. Minigene sub(36–40)pAmut contained a substitution mutation to the polyadenylation signal AAUAAA in intron 6 (for mutation sequence, see Fig. 4A). Exon 6 inclusion was measured by semiquantitative RT-PCR, and fold change between control siRNA-treated and CPSF1 siRNA-treated cells was calculated for each minigene. Fold changes and corresponding P-values are shown. (B) Levels of CPSF1 knockdown by siRNAs Hs_CPSF1_4 and Hs_CPSF1_6 were determined by Western blotting. CPSF1 knockdown by siRNA Hs_CPSF1_7 resulted in similar levels of CPSF1 depletion (data not shown).