Pelletier J, Sonenberg N
Department of Biochemistry, McGill University, Montréal, Que., Canada.
Biochem Cell Biol. 1987 Jun;65(6):576-81. doi: 10.1139/o87-074.
Translation initiation in eukaryotes is a complex process involving many factors. A key step in this process is the binding of mRNA to the 43S preinitiation complex. This is generally the rate-limiting step in translation initiation and consequently a major determinant of mRNA translational efficiency. The primary and secondary structure of the mRNA 5' noncoding region have been implicated in modulating translational efficiency. Translational efficiency was shown to be inversely proportional to the degree of secondary structure at the mRNA 5' noncoding region. Furthermore, it was shown that cap-binding proteins that interact with the 5' cap structure (m7GpppN) of eukaryotic mRNAs are involved in the "unwinding" of the mRNA secondary structure, in an ATP hydrolysis mediated event, to facilitate ribosome binding. Thus, cap-binding proteins can potentially regulate mRNA translation. Here, we discuss the available data supporting the notion that eukaryotic 5' mRNA secondary structure plays an important role in translation initiation and the possible regulation of this process.
真核生物中的翻译起始是一个涉及许多因素的复杂过程。这一过程中的关键步骤是mRNA与43S前起始复合物的结合。这通常是翻译起始中的限速步骤，因此也是mRNA翻译效率的主要决定因素。mRNA 5'非编码区的一级和二级结构与调节翻译效率有关。翻译效率与mRNA 5'非编码区的二级结构程度成反比。此外，研究表明，与真核生物mRNA的5'帽结构（m7GpppN）相互作用的帽结合蛋白参与了mRNA二级结构的“解旋”，这是一个由ATP水解介导的过程，以促进核糖体结合。因此，帽结合蛋白可能会调节mRNA翻译。在这里，我们讨论了现有数据，这些数据支持真核生物5' mRNA二级结构在翻译起始中起重要作用以及该过程可能受到调控的观点。
