Farberov Luba, Weissglas-Volkov Daphna, Shapira Guy, Zoabi Yazeed, Schiff Chen, Kloeckener-Gruissem Barbara, Neidhardt John, Shomron Noam
Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Edmond J. Safra Center for Bioinformatics, Tel Aviv University, Tel Aviv, Israel.
iScience. 2023 Aug 28;26(10):107723. doi: 10.1016/j.isci.2023.107723. eCollection 2023 Oct 20.
Splicing of transcripts is catalyzed by the spliceosome, a mega-complex consisting of hundreds of proteins and five snRNAs, which employs direct interactions. When U1 snRNA forms high-affinity binding, namely more than eight base pairs, with the 5'SS, the result is usually a suppressing effect on the splicing activity. This likely occurs due to the inefficient unwinding of U1/5'SS base-pairing or other regulatory obstructions. Here, we show and in patient-derived cell lines that pre-microRNAs can modulate the splicing reaction by interacting with U1 snRNA. This leads to reduced binding affinity to the 5'SS, and hence promotes the inclusion of exons containing 5'SS, despite sequence-based high affinity to U1. Application of the mechanism resulted in correction of the splicing defect in the disease-causing VCAN gene from an individual with Wagner syndrome. This pre-miRNA/U1 interaction can regulate the expression of alternatively spliced exons, thus extending the scope of mechanisms regulating splicing.
转录本的剪接由剪接体催化，剪接体是一种由数百种蛋白质和五种小核RNA组成的超大复合体，其通过直接相互作用发挥作用。当U1小核RNA与5'剪接位点（5'SS）形成高亲和力结合，即超过八个碱基对时，通常会对剪接活性产生抑制作用。这可能是由于U1/5'SS碱基配对解旋效率低下或其他调控障碍所致。在此，我们在患者来源的细胞系中证明，前体微小RNA可以通过与U1小核RNA相互作用来调节剪接反应。这导致其与5'SS的结合亲和力降低，因此尽管基于序列对U1具有高亲和力，但仍能促进包含5'SS的外显子的包含。应用该机制可纠正患有瓦格纳综合征个体的致病基因VCAN中的剪接缺陷。这种前体微小RNA/U1相互作用可以调节可变剪接外显子的表达，从而扩展了调控剪接的机制范围。
