The alternative splicing program of differentiated smooth muscle cells involves concerted non-productive splicing of post-transcriptional regulators.
The alternative splicing program of differentiated smooth muscle cells involves concerted non-productive splicing of post-transcriptional regulators.
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DOI：
10.1093/nar/gkw560
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发表时间：
2016-10-14
影响因子：
14.9
通讯作者：
Smith CW
中科院分区：
文献类型：
--
作者：
Llorian M;Gooding C;Bellora N;Hallegger M;Buckroyd A;Wang X;Rajgor D;Kayikci M;Feltham J;Ule J;Eyras E;Smith CW
选择性剪接 (AS) 是驱动细胞分化的基因表达程序的关键组成部分。平滑肌细胞 (SMC) 在许多生理系统的功能中发挥着重要作用；然而，对 SMC AS 的调查仅限于少数事件。我们分析了小鼠去分化 SMC 中转录组的变化，并观察了数百个 AS 事件的变化。分化细胞中包含的外显子的特征是特别弱的剪接位点和聚嘧啶束结合蛋白（PTBP1）的上游结合位点。与此一致的是，敲低实验表明 PTBP1 抑制许多平滑肌特异性外显子。我们还观察到协调剪接变化预计会下调分化细胞中 U1 和 U2 snRNP 核心成分、剪接调节因子和其他转录后因子的表达。与未分化细胞相比，分化细胞的同源蛋白水平较低或相似。然而，snRNA 的水平并不跟随剪接蛋白的表达，在 U1 snRNP 的情况下，我们看到 U1 snRNA 和 U1 snRNP 蛋白水平的相互变化。我们的结果表明，分化的 SMC 中的 AS 程序是通过辅助 RNA 结合蛋白（例如 PTBP1）的综合影响以及核心剪接机制的活性和化学计量的改变而精心策划的。
Alternative splicing (AS) is a key component of gene expression programs that drive cellular differentiation. Smooth muscle cells (SMCs) are important in the function of a number of physiological systems; however, investigation of SMC AS has been restricted to a handful of events. We profiled transcriptome changes in mouse de-differentiating SMCs and observed changes in hundreds of AS events. Exons included in differentiated cells were characterized by particularly weak splice sites and by upstream binding sites for Polypyrimidine Tract Binding protein (PTBP1). Consistent with this, knockdown experiments showed that that PTBP1 represses many smooth muscle specific exons. We also observed coordinated splicing changes predicted to downregulate the expression of core components of U1 and U2 snRNPs, splicing regulators and other post-transcriptional factors in differentiated cells. The levels of cognate proteins were lower or similar in differentiated compared to undifferentiated cells. However, levels of snRNAs did not follow the expression of splicing proteins, and in the case of U1 snRNP we saw reciprocal changes in the levels of U1 snRNA and U1 snRNP proteins. Our results suggest that the AS program in differentiated SMCs is orchestrated by the combined influence of auxiliary RNA binding proteins, such as PTBP1, along with altered activity and stoichiometry of the core splicing machinery.
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影响因子：
4.3
作者：
Corvelo A;Hallegger M;Smith CW;Eyras E
通讯作者：
Eyras E
影响因子：
10.5
作者：
Boutz PL;Bhutkar A;Sharp PA
通讯作者：
Sharp PA
影响因子：
7
作者：
Braunschweig U;Barbosa-Morais NL;Pan Q;Nachman EN;Alipanahi B;Gonatopoulos-Pournatzis T;Frey B;Irimia M;Blencowe BJ
通讯作者：
Blencowe BJ
影响因子：
14.9
作者：
Gooding C;Edge C;Lorenz M;Coelho MB;Winters M;Kaminski CF;Cherny D;Eperon IC;Smith CW
通讯作者：
Smith CW
影响因子：
64.5
作者：
Braunschweig U;Gueroussov S;Plocik AM;Graveley BR;Blencowe BJ
通讯作者：
Blencowe BJ