Understanding the splicing code can be challenging as several splicing factors bind to many splicing‐regulatory elements. The SMN1 and SMN2 silencer element ISS‐N1 is the target of the antisense oligonucleotide drug, Spinraza, which is the treatment against spinal muscular atrophy. However, limited knowledge about the nature of the splicing factors that bind to ISS‐N1 and inhibit splicing exists. It is likely that the effect of Spinraza comes from blocking binding of these factors, but so far, an unbiased characterization has not been performed and only members of the hnRNP A1/A2 family have been identified by Western blot analysis and nuclear magnetic resonance to bind to this silencer. Employing an MS/MS‐based approach and surface plasmon resonance imaging, we show for the first time that splicing factor SRSF10 binds to ISS‐N1. Furthermore, using splice‐switching oligonucleotides we modulated the splicing of the SRSF10 isoforms generating either the long or the short protein isoform of SRSF10 to regulate endogenous SMN2 exon 7 inclusion. We demonstrate that the isoforms of SRSF10 regulate SMN1 and SMN2 splicing with different strength correlating with the length of their RS domain. Our results suggest that the ratio between the SRSF10 isoforms is important for splicing regulation.

中文翻译：

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将 SRSF10 鉴定为 SMN2 ISS-N1 的调节剂

理解拼接代码可能具有挑战性，因为几个拼接因素与许多拼接监管元素结合在一起。SMN1和SMN2 _消音元件 ISS-N1 是反义寡核苷酸药物 Spiraza 的靶标，该药物是治疗脊髓性肌萎缩症的药物。然而，关于与 ISS-N1 结合并抑制剪接的剪接因子的性质知之甚少。Spiraza 的作用很可能来自阻断这些因子的结合，但到目前为止，尚未进行公正的表征，并且通过蛋白质印迹分析和核磁共振仅鉴定了 hnRNP A1/A2 家族的成员以结合到这个消音器。采用基于 MS/MS 的方法和表面等离子共振成像，我们首次显示剪接因子 SRSF10 与 ISS-N1 结合。此外，我们使用剪接转换寡核苷酸调节了SRSF10的剪接产生 SRSF10 的长或短蛋白亚型以调节内源性SMN2外显子 7 包含的亚型。我们证明了 SRSF10 的亚型调节SMN1和SMN2剪接，其强度与其 RS 结构域的长度相关。我们的结果表明，SRSF10 亚型之间的比率对于剪接调节很重要。