Figure 3.

FBI-1 modulates BCL-X splicing in SAM68-dependent manner.

A Schematic representation of BCL-X splice variants (upper panel). Analysis of endogenous BCL-X splicing in HEK293T cells transfected with control (si-CTRL) or FBI-1 (si-FBI-1) siRNAs. Western blot analyses (lower panel) for the indicated proteins and agarose gel of the RT–PCR analysis are shown.

B qRT-PCR analysis of BCL-X variants using exon junction primers performed in HEK293T and PC3 cells transfected with control (si-CTRL) or FBI-1 (si-FBI-1) siRNAs. Fold variation of each sample was calculated by delta-delta C_t method as described in Supporting information.

C, D Analysis of in vivo splicing assay of BCL-X minigene in HEK293T cells transfected with Flag-FBI-1 (FBI-1) or Myc-FBI-1_CT (C), or with control (si-CTRL) or SAM68 (si-SAM68) siRNAs and Flag-FBI-1 (D). In (C), the BCL-X_S/BCL-X_L ratio of the control sample (empty vector) was set to 1.

E, F Analysis of in vivo splicing assay of BCL-X minigene in BPH1 and PC3 cells (E) or in PC3 cells transfected with control (si-CTRL) or FBI-1 (si-FBI) siRNAs (F) in the presence of GFP-SAM68.

Data information: In (D–F): Western blots (upper panel), agarose gels of the RT–PCR analyses (middle panel), and bar graphs (bottom panel) of the BCL-X_S/BCL-X_L ratio. P-values of Student's t-test: *P < 0.05; **P < 0.01; ***P < 0.001; n.s., not significant; mean ± s.d., n = 3.