Role of mRNA competition in regulating translation: further characterization of mRNA discriminatory initiation factors.
Role of mRNA competition in regulating translation: further characterization of mRNA discriminatory initiation factors.
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mRNA 竞争在调节翻译中的作用：mRNA 歧视起始因素的进一步表征。
DOI：
10.1073/pnas.80.3.663
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发表时间：
1983
影响因子：
11.1
通讯作者：
Thach,RE
中科院分区：
文献类型：
--
作者：
Ray,BK;Brendler,TG;Adya,S;Daniels-McQueen,S;Miller,JK;Hershey,JW;Grifo,JA;Merrick,WC;Thach,RE
宿主和呼肠孤病毒 mRNA 在受感染细胞中相互竞争翻译。动力学分析表明，竞争位点是一个信息歧视起始因子，必须先与 mRNA 结合，然后才能与 40S 核糖体亚基相互作用。本通报描述了一种可以检测消息歧视活动的体外测定。通过使用呼肠孤病毒和珠蛋白 mRNA 建立竞争情况，然后测量通过添加成分缓解这种竞争的特异性。在用该测定调查的各种起始因子中，有两个具有 mRNA 区分因子的预期特性。它们是真核起始因子 4A 和“帽结合蛋白”复合物。由于帽结合蛋白复合物含有与起始因子eIF-4A相似或相同的亚基，因此后一种因子似乎只有一种形式可能在体内有活性。在体外，这两个因素根据相似的层次结构缓解了加帽和未加帽呼肠孤病毒 mRNA 之间的竞争。这些结果表明，除了m7G帽之外的一些特征，例如核苷酸序列或二级结构，可以被区分因素识别。
Host and reovirus mRNAs compete with one another for translation in infected cells. Kinetic analysis has suggested that the site of competition is a message discriminatory initiation factor which must bind to the mRNA before it can interact with the 40S ribosomal subunit. The present communication describes an in vitro assay which can detect message discriminatory activities. A competitive situation is established by using reovirus and globin mRNAs, and then the specificity with which this competition is relieved by added components is measured. Among the various initiation factors surveyed with this assay, two have the properties expected of the mRNA discriminatory factor. These are eukaryotic initiation factor 4A and a "cap binding protein" complex. Inasmuch as the cap binding protein complex contains a subunit similar or identical to the initiation factor eIF-4A, it seems likely that only one form of the latter factor may be active in vivo. In vitro, both factors relieve competition among both capped and uncapped reovirus mRNAs according to similar hierarchies. These results suggest that some feature other than the m7G cap, such as nucleotide sequence or secondary structure, is recognized by the discriminatory factor.