Human U4/U6 snRNP recycling factor p110:: Mutational analysis reveals the function of the tetratricopeptide repeat domain in recycling
Human U4/U6 snRNP recycling factor p110:: Mutational analysis reveals the function of the tetratricopeptide repeat domain in recycling
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DOI：
10.1128/mcb.24.17.7392-7401.2004
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发表时间：
2004-09-01
影响因子：
5.3
通讯作者：
Bindereif, A
中科院分区：
文献类型：
--
作者：
Medenbach, J;Schreiner, S;Bindereif, A
在每个剪接体周期后，U4和U6 snRNAs分别被释放，并被循环到功能性的U4/U6 snRNP中，在哺乳动物系统中需要U6特异性RNA结合蛋白p110 （SART3）。其结构域结构由至少包含7个四肽重复（TPR）基序的宽n端结构域、2个RNA识别基序（RRMs）和一个包含10个氨基酸的高度保守的c端序列组成。在体外循环条件下，我们证明了U6-p110是一个必不可少的剪接因子。再循环活动需要RRMs和TPR结构域，但不需要高度保守的c端序列。对于u6特异性RNA的结合，两个带有一些侧翼区域的RRMs就足够了。酵母双杂交实验表明，p110通过其TPR结构域与U4/ u6特异性90K蛋白相互作用，表明TPR结构域在剪接体循环中的特殊作用。在90K蛋白上，一个短的内部区域（氨基酸416至550）足以与p110相互作用。总之，这些数据表明p110通过rna -蛋白和蛋白-蛋白相互作用将U4和U6 snrna聚集在一起的模型。
After each spliceosome cycle, the U4 and U6 snRNAs are released separately and are recycled to the functional U4/U6 snRNP, requiring in the mammalian system the U6-specific RNA binding protein p110 (SART3). Its domain structure is made up of an extensive N-terminal domain with at least seven tetratricopeptide repeat (TPR) motifs, followed by two RNA recognition motifs (RRMs) and a highly conserved C-terminal sequence of 10 amino acids. Here we demonstrate under in vitro recycling conditions that U6-p110 is an essential splicing factor. Recycling activity requires both the RRMs and the TPR domain but not the highly conserved C-terminal sequence. For U6-specific RNA binding, the two RRMs with some flanking regions are sufficient. Yeast two-hybrid assays reveal that p110 interacts through its TPR domain with the U4/U6-specific 90K protein, indicating a specific role of the TPR domain in spliceosome recycling. On the 90K protein, a short internal region (amino acids 416 to 550) suffices for the interaction with p110. Together, these data suggest a model whereby p110 brings together U4 and U6 snRNAs through both RNA-protein and protein-protein interactions.