The tissue-specific RNA binding protein T-STAR controls regional splicing patterns of neurexin pre-mRNAs in the brain.
The tissue-specific RNA binding protein T-STAR controls regional splicing patterns of neurexin pre-mRNAs in the brain.
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DOI：
10.1371/journal.pgen.1003474
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发表时间：
2013-04
期刊：
影响因子：
4.5
通讯作者：
Elliott DJ
中科院分区：
文献类型：
--
作者：
Ehrmann I;Dalgliesh C;Liu Y;Danilenko M;Crosier M;Overman L;Arthur HM;Lindsay S;Clowry GJ;Venables JP;Fort P;Elliott DJ
RNA结合蛋白T-STAR是在5.2亿至6.1亿年前的基因三重化后产生的，这也产生了它的两个同源物Sam 68和SLM-1。在这里，我们已经创建了一个T-STAR无效小鼠，以确定这种RNA结合蛋白的内源性功能。考虑到T-STAR在睾丸和脑中的高表达，以及已知的Sam 68缺失小鼠的不育和多效性缺陷，T-STAR缺失小鼠发育正常并且是可生育的，这是令人惊讶的。使用转录组范围内搜索成人大脑中的剪接靶点，我们确定T-STAR蛋白作为来自每个Neurexin 1 -3基因的选择性剪接片段4（AS 4）外显子和Stxbp 5l基因的外显子23的有效剪接阻遏物。T-STAR蛋白在前脑衍生的结构如海马中高度集中，其也显示出最大的Neurexin 1 -3 AS 4剪接抑制。在缺乏内源性T-STAR蛋白的情况下，Nrxn 1 -3 AS 4剪接抑制显著降低，尽管有Sam 68的生理共表达。在转染细胞中，Neurexin 3 AS 4选择性剪接受T-STAR或Sam 68蛋白的调节。相比之下，Neurexin 2 AS 4剪接仅受T-STAR调节，通过紧接着自骨脊椎动物辐射以来保守的受调节外显子下游的富含UWAA的反应元件。Nrxn 1和Nrxn 3基因中的AS 4外显子也与不同的保守UWAA重复模式相关。与古老的剪接控制机制一致，人类T-STAR蛋白能够抑制斑马鱼Nrxn 3 AS 4外显子的剪接包含。尽管Neurexin 1 -3和Stxbp 5l编码关键的突触蛋白，但T-STAR敲除小鼠没有可检测到的空间记忆缺陷，尽管海马中几乎完全没有AS 4剪接抑制。我们的工作确定T-STAR是一种古老而有效的组织特异性剪接调节因子，它使用浓度依赖性机制来协调调节小鼠大脑中Neurexin 1 -3 AS 4外显子的区域剪接模式。选择性剪接在动物发育中起着关键作用，并且在很大程度上受RNA结合蛋白的表达控制。大多数RNA结合蛋白作为称为旁系同源物的姐妹蛋白家族存在，其由基因扩增产生，包括与Sam 68和SLM-1密切相关的T-STAR。T-STAR、Sam 68和SLM-1在转染细胞中的剪接控制中通常表现相同。在这里，我们报告的T-STAR蛋白的生理功能，通过敲除其亲本基因在小鼠中。令人惊讶的是，我们观察到没有T-STAR蛋白的生殖细胞成熟没有缺陷，这是一个意想不到的结果，因为T-STAR蛋白主要在睾丸中表达，并且它的副产物Sam 68对男性生育力是必需的。相反，我们发现T-STAR控制着一组编码重要突触蛋白的剪接靶点。T-STAR作为一种有效的剪接阻遏物，在大脑中建立这些靶外显子的区域剪接模式。前脑衍生的结构如海马强烈表达T-STAR蛋白来抑制这些靶外显子。一些T-STAR调节的剪接靶点与Sam 68重叠，但T-STAR也调节自己不同的靶点。比较基因组分析与T-STAR剪接控制的古老机制一致，该机制自骨脊椎动物辐射以来一直保守。
The RNA binding protein T-STAR was created following a gene triplication 520–610 million years ago, which also produced its two parologs Sam68 and SLM-1. Here we have created a T-STAR null mouse to identify the endogenous functions of this RNA binding protein. Mice null for T-STAR developed normally and were fertile, surprisingly, given the high expression of T-STAR in the testis and the brain, and the known infertility and pleiotropic defects of Sam68 null mice. Using a transcriptome-wide search for splicing targets in the adult brain, we identified T-STAR protein as a potent splicing repressor of the alternatively spliced segment 4 (AS4) exons from each of the Neurexin1-3 genes, and exon 23 of the Stxbp5l gene. T-STAR protein was most highly concentrated in forebrain-derived structures like the hippocampus, which also showed maximal Neurexin1-3 AS4 splicing repression. In the absence of endogenous T-STAR protein, Nrxn1-3 AS4 splicing repression dramatically decreased, despite physiological co-expression of Sam68. In transfected cells Neurexin3 AS4 alternative splicing was regulated by either T-STAR or Sam68 proteins. In contrast, Neurexin2 AS4 splicing was only regulated by T-STAR, through a UWAA-rich response element immediately downstream of the regulated exon conserved since the radiation of bony vertebrates. The AS4 exons in the Nrxn1 and Nrxn3 genes were also associated with distinct patterns of conserved UWAA repeats. Consistent with an ancient mechanism of splicing control, human T-STAR protein was able to repress splicing inclusion of the zebrafish Nrxn3 AS4 exon. Although Neurexin1-3 and Stxbp5l encode critical synaptic proteins, T-STAR null mice had no detectable spatial memory deficits, despite an almost complete absence of AS4 splicing repression in the hippocampus. Our work identifies T-STAR as an ancient and potent tissue-specific splicing regulator that uses a concentration-dependent mechanism to co-ordinately regulate regional splicing patterns of the Neurexin1-3 AS4 exons in the mouse brain. Alternative splicing plays a key role in animal development and is largely controlled by the expression of RNA binding proteins. Most RNA binding proteins exist as families of sister proteins called paralogs, which result from gene amplification, including T-STAR, which is closely related to Sam68 and SLM-1. T-STAR, Sam68, and SLM-1 usually behave identically in splicing control in transfected cells. Here we report the physiological functions of T-STAR protein by knocking its parent gene out in the mouse. Surprisingly we observed no defects in germ cell maturation without T-STAR protein, an unexpected result given T-STAR protein is mainly expressed in the testis and its paralog Sam68 is essential for male fertility. Instead, we find T-STAR controls a panel of splicing targets that encode important synaptic proteins. T-STAR acts as a potent splicing repressor to establish regional splicing patterns of these target exons in the brain. Forebrain-derived structures like the hippocampus strongly express T-STAR protein to repress these target exons. Some T-STAR regulated splicing targets overlap with Sam68, but T-STAR also regulates its own distinct targets. Comparative genomic analyses are consistent with an ancient mechanism of splicing control by T-STAR that has been conserved since the radiation of bony vertebrates.
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影响因子：
3.9
作者：
Elliott DJ;Best A;Dalgliesh C;Ehrmann I;Grellscheid S
通讯作者：
Grellscheid S
影响因子：
2.7
作者：
Deindl, E
通讯作者：
Deindl, E
影响因子：
5.3
作者：
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通讯作者：
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鉴定进化保守的外显子是发育中剪接激活剂TRA2β的调节靶标。
影响因子：
4.5
作者：
Grellscheid S;Dalgliesh C;Storbeck M;Best A;Liu Y;Jakubik M;Mende Y;Ehrmann I;Curk T;Rossbach K;Bourgeois CF;Stévenin J;Grellscheid D;Jackson MS;Wirth B;Elliott DJ
通讯作者：
Elliott DJ
影响因子：
14.9
作者：
Fujita PA;Rhead B;Zweig AS;Hinrichs AS;Karolchik D;Cline MS;Goldman M;Barber GP;Clawson H;Coelho A;Diekhans M;Dreszer TR;Giardine BM;Harte RA;Hillman-Jackson J;Hsu F;Kirkup V;Kuhn RM;Learned K;Li CH;Meyer LR;Pohl A;Raney BJ;Rosenbloom KR;Smith KE;Haussler D;Kent WJ
通讯作者：
Kent WJ