Human tra2-beta1 autoregulates its protein concentration by influencing alternative splicing of its pre-mRNA
Human tra2-beta1 autoregulates its protein concentration by influencing alternative splicing of its pre-mRNA
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DOI：
10.1093/hmg/ddh051
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发表时间：
2004-03-01
影响因子：
3.5
通讯作者：
Stamm, S
中科院分区：
文献类型：
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作者：
Stoilov, P;Daoud, R;Stamm, S
HTRA 2-BETA1是一种SR样蛋白，以浓度依赖性方式调节可变剪接位点选择。其适当浓度是重要的，因为几种病理状态与其变化有关。我们研究了控制细胞HTRA 2-BETA1浓度的机制，发现它利用负反馈环来调节其外显子2的剪接。TRA 2-BETA1与外显子2中存在的四个增强子结合，从而激活其包含。包含外显子2产生不翻译成蛋白质的mRNA。外显子2增强子的突变表明TRA 2-BETA1结合简并序列GHVVGANR，其在外显子中比在内含子中更常见。TRA 2-BETA1的过度磷酸化强烈降低了其与RNA的结合。CLK 2激酶的存在阻止外显子2和3的使用，产生htra 2-β 3 mRNA。所得的HTRA 2-BETA3蛋白缺乏HTRA 2-BETA1的第一个RS结构域，在几种组织中表达，并且对tra 2-β剪接位点选择没有影响。HTRA 2-BETA1相互作用蛋白通过螯合外显子2促进外显子2跳跃，这上调HTRA 2-BETA1蛋白合成。我们认为，tra 2-beta前mRNA选择性剪接的调节提供了一个强大而灵敏的分子传感器，可以测量HTRA 2-BETA1及其相互作用蛋白之间的比例。
HTRA2-BETA1 is an SR-like protein that regulates alternative splice site selection in a concentration-dependent manner. Its proper concentration is important as several pathological states are associated with its change. We investigated the mechanism that controls the cellular HTRA2-BETA1 concentration and found it utilizes a negative feedback loop to regulate the splicing of its exon 2. TRA2-BETA1 binds to four enhancers present in exon 2, which activates its inclusion. Inclusion of exon 2 generates mRNAs that are not translated into proteins. Mutations of exon 2 enhancers demonstrate that TRA2-BETA1 binds a degenerate sequence GHVVGANR, which is found more frequently in exons than in introns. Hyperphosphorylation of TRA2-BETA1 strongly reduces its binding to RNA. Presence of the CLK2 kinase prevents the usage of exons 2 and 3, generating the htra2-beta3 mRNA. The resulting HTRA2-BETA3 protein lacks the first RS domain of HTRA2-BETA1, is expressed in several tissues and has no influence on tra2-beta splice site selection. HTRA2-BETA1 interacting proteins promote exon 2 skipping by sequestering it, which upregulates the HTRA2-BETA1 protein synthesis. We propose that the regulation of the tra2-beta pre-mRNA alternative splicing provides a robust and sensitive molecular sensor that measures the ratio between HTRA2-BETA1 and its interacting proteins.