Figure 1

Alternative splicing of the CUGBP2 gene. (A) Schematic representation of the CUGBP2 protein and the CUGBP2 R3δ isoform. The upper panel shows CUGBP2 and its domains. RRMs represent the RNA-binding domains. The NLS (line), NES (broken line), and splicing activation domain (gray line) were determined in a previous report [27]. The lower panel shows the alternatively spliced form of CUGBP2, the R3δ isoform. (B) Schematic representation of exon 14 and its adjacent region in the CUGBP2 gene. Exons are indicated as black boxes with the alternatively spliced exons indicated as gray boxes. Introns are indicated by a central narrow line. Arrows show primer sites. (C) Expression analysis of CUGBP2 in adult mouse tissues. Semi-quantitative RT-PCR was performed using primers to detect the alternatively spliced exon of CUGBP2. The right side indicates the positions of exon 14 skipping or inclusion products. β-Actin was used as a control. (D) Expression analysis of CUGBP2 in P19 neural differentiation. The right side indicates the positions of exon 14 skipping or inclusion products. β-Actin was used as a control. Relative amounts of exon 14 skipping and inclusion products were estimated by densitometry. Changes of total expression levels were normalized using brain samples (C) or Day 0 samples (D). The error bars indicate the standard error. The values under the gel images indicate the percentage of the exon 14 skipping in total CUGBP2 transcripts. (E) Western blot analysis of CUGBP2. Whole cell extracts of P19 cells (2 μg) were used to detect the changes in the amount of full-length CUGBP2 in the upper panel. The middle panel shows the R3δ isoform detected using 7 μg of each extract. GAPDH was used as a control and is shown in the lower panel.