The yeast nuclear cap binding complex can interact with translation factor elF4G and mediate translation initiation
The yeast nuclear cap binding complex can interact with translation factor elF4G and mediate translation initiation
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DOI：
10.1016/s1097-2765(00)00020-4
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发表时间：
2000-07-01
期刊：
影响因子：
16
通讯作者：
Sachs, AB
中科院分区：
文献类型：
--
作者：
Fortes, P;Inada, T;Sachs, AB
MRNA帽结构由核(CBC)或细胞质(EIF4F)帽结合复合体结合。在信使核糖核酸输出后，CBC必须在细胞质中被交换成eIF4F。目前尚不清楚这种交换是如何发生的，也不知道这种RNP重塑事件是如何与mRNA功能整合的。在这里，我们报告了遗传和生化证据，表明酵母翻译起始因子eIF4G与CBC相关，而结合CAP和eIF4G的eIF4F成分eIF4E拮抗这种相互作用。此外，我们发现CBC可以刺激含有eIF4G蛋白的提取物中的翻译，该蛋白缺乏eIF4E结合。这些数据表明，eIF4E与新输出的mRNA上的eIF4G-CBC复合体结合取代了CBC，并且第一轮对mRNA的翻译可能通过一种不同于随后几轮的机制发生。
The mRNA cap structure is bound by either the nuclear (CBC) or the cytoplasmic (eIF4F) cap binding complex. Following mRNA export, CBC must be exchanged for eIF4F in the cytoplasm. It is not known how this exchange occurs or how this RNP remodeling event is integrated with mRNA function. Here we report genetic and biochemical evidence that the yeast translation initiation factor eIF4G associates with CBC, and that eIF4E, the eIF4F component that binds both the cap and eIF4G, antagonizes this interaction. Furthermore, we find that CBC can stimulate translation in extracts containing an eIF4G protein deficient for eIF4E binding. These data suggest that eIF4E binding to the eIF4G-CBC complex on newly exported mRNA displaces CBC, and that the first round of translation on mRNA may occur via a different mechanism than subsequent rounds.