Human, Drosophila, and C-elegans TDP43:: Nucleic acid binding properties and splicing regulatory function
Human, Drosophila, and C-elegans TDP43:: Nucleic acid binding properties and splicing regulatory function
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DOI：
10.1016/j.jmb.2005.02.038
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发表时间：
2005-05-06
影响因子：
5.6
通讯作者：
Baralle, FE
中科院分区：
文献类型：
--
作者：
Ayala, YM;Pantano, S;Baralle, FE
TAR DNA结合蛋白（TDP43）是一种高度保守的异质核核糖核蛋白，通过特异性结合3'剪接位点上游一个富含ugg的多态性区域，下调9外显子囊性纤维化跨膜传导调节因子（CFTR）的剪接。尽管关于该蛋白的核定位和剪接调节活性的新信息出现，但TDP43在细胞中的作用仍然难以捉摸。为了研究人类TDP43及其同源物的功能，我们克隆了黑腹果蝇和秀丽隐杆线虫的TDP43蛋白并对其进行了鉴定。来自人类、苍蝇和蠕虫的蛋白质在其核酸结合特异性上表现出惊人的相似性。我们发现两个不同位置的残基在TDP43家族成员中表现出很强的保守性，这与目标序列的紧密识别有关。我们的三维模型预测了TDP43配合物的（UG）(m)序列，这些残基使氨基酸侧链与碱基接触。此外，我们的研究结果表明，果蝇TDP43在调节外显子剪接方面与人类TDP43相当。另一方面，秀丽隐杆线虫TDP43对外显子识别没有影响。秀丽隐杆线虫的TDP43缺乏在其他两个同源物的羧基端发现的富含甘氨酸的结构域。人类和果蝇TDP43缺乏c端结构域的突变体同样不能影响剪接。我们的研究表明，富含甘氨酸的结构域对人类和果蝇TDP43的剪接调节至关重要。(c) 2005 Elsevier Ltd版权所有。
TAR DNA binding protein (TDP43), a highly conserved heterogeneous nuclear ribonucleoprotein, was found to down-regulate splicing of the exon 9 cystic fibrosis transmembrane conductance regulator (CFTR) through specific binding to a UG-rich polymorphic region upstream of the 3' splice site. Despite the emergence of new information regarding the protein's nuclear localization and splicing regulatory activity, TDP43's role in cells remains elusive. To investigate the function of human TDP43 and its homologues, we cloned and characterized the proteins from Drosophila melanogaster and Caenorhabditis elegans. The proteins from human, fly, and worm show striking similarities in their nucleic acid binding specificity. We found that residues at two different positions, which show a strong conservation among TDP43 family members, are linked to the tight recognition of the target sequence. Our three-dimensional model of TDP43 in complex with a (UG)(m) sequence predicts that these residues make amino acid side-chain to base contacts. Moreover, our results suggest that Drosophila TDP43 is comparable to human TDP43 in regulating exon splicing. On the other hand, C. elegans TDP43 has no effect on exon recognition. TDP43 from C. elegans lacks the glycine-rich domain found at the carboxy terminus of the other two homologues. Mutants of human and fly TDP43 devoid of the C-terminal domain are likewise unable to affect splicing. Our studies suggest that the glycine-rich domain is essential for splicing regulation by human and fly TDP43. (c) 2005 Elsevier Ltd. All rights reserved.