Characterization of BIN1 isoforms in primary and CTCL cells. (A) Schematic diagram of protein domains and exon organization of BIN1 and the specific primers sets generated to detect exons 10, 12A-D, and 13: BIN1 9/10, BIN1 9/11, and BIN1 11/14. BAR indicates BIN1/Amphiphysin/RVS167-related; U, unique; NTS, neural tissue specific; MBD, MYC-binding domain; and SH3, Src homology 3. (B) Yield of both BIN1 9/10 and BIN1 9/11 PCR products by RT-PCR indicates differential splicing of exon 10. Lane 1 indicates Hut 78; lane 2, Hut 78 RPG; lane 3, Hut 78/sh4 bulk; lane 4, Hut 78/sh4 clone 1. (C) Quantitative RT-PCR using the BIN1 9/10 primer set demonstrated up-regulation of BIN1 transcripts containing exon 10 in AHI-1–suppressed cells compared with the control Hut 78 cells. (D) Four distinct RT-PCR products were identified and cloned in Hut 78 cell lines using BIN1 11/14 primers. Lane 1 indicates Hut 78; lane 2, Hut 78 RPG; lane 3, Hut 78/sh4 bulk; lane 4, Hut 78/sh4 clone 1; lane 5, negative control (no RNA); lane 6, positive control (Hut 78 RPG with GAPDH primer set). (E) RT-PCR revealed that the 4 BIN1 11/14 RT-PCR products identified in the Hut 78-transduced cells were also present in both CD4⁺CD7⁻ SS patients samples and in normal controls. (F) Schematic diagram of the differential splicing of exons 12A and 13 characterized in both the Hut 78 cell lines and primary samples. (G) Quantitative RT-PCR using a BIN1 12A primer set demonstrated up-regulation of BIN1 transcripts containing exon 12A in AHI-1–suppressed cells compared with the control Hut 78 cells. Values shown are the mean plus or minus SEM. The P values presented are the result of 2-sample t tests comparing the AHI-1–suppressed expression data to that of Hut 78 controls.