INTERNAL INITIATION OF TRANSLATION MEDIATED BY THE 5' LEADER OF A CELLULAR MESSENGER-RNA
INTERNAL INITIATION OF TRANSLATION MEDIATED BY THE 5' LEADER OF A CELLULAR MESSENGER-RNA
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DOI：
10.1038/353090a0
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发表时间：
1991-09-05
期刊：
影响因子：
64.8
通讯作者：
SARNOW, P
中科院分区：
文献类型：
--
作者：
MACEJAK, DG;SARNOW, P
核糖体扫描模型已被提出来解释真核信使 RNA 1 的起始，其中 mRNA 末端的甲基化帽结构与帽结合蛋白复合物 eIF-4F 之间的相互作用促进了 43S 三元核糖体亚基靠近或位于 mRNA 5' 端的结合（参考文献 2、3）。但小核糖核酸病毒 mRNA 不具有 5' 末端帽结构，并通过内部核糖体结合 4-7 进行翻译。 当宿主细胞 mRNA 的帽子依赖性翻译受到抑制时，编码免疫球蛋白重链结合蛋白的细胞 mRNA 可以在脊髓灰质炎病毒感染的细胞中进行翻译 8。我们在此报告，结合蛋白 mRNA 的 5' 前导序列可以直接赋予哺乳动物细胞中 mRNA 的内部核糖体结合能力，表明真核 mRNA 使用内部核糖体结合机制启动翻译。
A RIBOSOME-SCANNING model has been proposed to explain the initiation of eukaryotic messenger RNAs 1 in which binding of the 43S ternary ribosomal subunit near or at the 5' end of the mRNA is facilitated by an interaction between the methylated cap-structure at the end of the mRNA and the cap-binding protein complex eIF-4F (refs 2, 3). But picornaviral mRNAs do not have a 5' terminal cap structure and are translated by internal ribosome binding 4-7. A cellular mRNA, encoding the immunoglobulin heavy-chain binding protein, can be translated in poliovirus-infected cells at a time when cap-dependent translation of host cell mRNAs is inhibited 8. We report here that the 5' leader of the binding protein mRNA can directly confer internal ribosome binding to an mRNA in mammalian cells, indicating that translation initiation by an internal ribosome-binding mechanism is used by eukaryotic mRNAs.