The exon junction core complex is locked onto RNA by inhibition of eIF4AIII ATPase activity
The exon junction core complex is locked onto RNA by inhibition of eIF4AIII ATPase activity
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DOI：
10.1038/nsmb990
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发表时间：
2005-10-01
影响因子：
16.8
通讯作者：
Le Hir, H
中科院分区：
文献类型：
--
作者：
Ballut, L;Marchadier, B;Le Hir, H
多蛋白外显子连接复合物（EJC）作为剪接的结果组装在mRNA上。EJC核心组分保持对mRNA的稳定控制，即使在mRNA行进到细胞质时整个EJC蛋白质组成演变。在这里，我们表明，重组EJC亚基MLN 51，MAGOH和Y14，连同DEAD盒蛋白eIF 4AIII绑定到ATP，是必要的，足以形成一个高度稳定的复合物的单链RNA。交联和RNA酶保护研究表明，这种重组复合物概括了EJC核心。重组EJC核心与RNA的稳定结合通过MAGOH-Y14抑制eIF 4AIII ATP酶活性来维持。我们阐明了EJC与RNA结合的方式，并提供了细胞机器如何使用RNA解旋酶以稳定和不依赖于序列的方式将几种蛋白质夹在RNA上的第一个例子。
The multiprotein exon junction complex (EJC) is assembled on mRNAs as a consequence of splicing. EJC core components maintain a stable grip on mRNAs even as the overall EJC protein composition evolves while mRNAs travel to the cytoplasm. Here we show that recombinant EJC subunits MLN51, MAGOH and Y14, together with the DEAD-box protein eIF4AIII bound to ATP, are necessary and sufficient to form a highly stable complex on single-stranded RNA. Cross-linking and RNase protection studies indicate that this recombinant complex recapitulates the EJC core. The stable association of the recombinant EJC core with RNA is maintained by inhibition of eIF4AIII ATPase activity by MAGOH-Y14. We elucidate the modalities of EJC binding to RNA and provide the first example of how cellular machineries may use RNA helicases to clamp several proteins onto RNA in stable and sequence-independent manners.