Translation and Cancer Laboratory, Unit of Biomedical Research on Cancer, National Institute of Cancer (Instituto Nacional de Cancerología, INCan), 22 San Fernando Ave., Tlalpan, 14080 Mexico City, Mexico.
Translation and Cancer Laboratory, Unit of Biomedical Research on Cancer, National Institute of Cancer (Instituto Nacional de Cancerología, INCan), 22 San Fernando Ave., Tlalpan, 14080 Mexico City, Mexico.
J Mol Biol. 2020 Dec 4;432(24):166702. doi: 10.1016/j.jmb.2020.10.035. Epub 2020 Nov 7.
Translation in eukaryotes is dependent on the activity of translation initiation factor (eIF) 4G family of proteins, a scaffold protein that, during the initiation step, coordinates the activity of other eIFs to recruit the 40S ribosomal subunit to the mRNA. Three decades of research on protein synthesis and its regulation has provided a wealth of evidence supporting the crucial role of cap-dependent translation initiation, which involves eIF4G. However, the recent discovery of a surprising variety of alternative mechanisms to initiate translation in the absence of eIF4G has stirred the orthodox view of how protein synthesis is performed. These mechanisms involve novel interactions among known eIFs, or between known eIFs and other proteins not previously linked to translation. Thus, a new picture is emerging in which the unorthodox translation initiation complexes contribute to the diversity of mechanisms that regulate gene expression in eukaryotes.
真核生物的翻译依赖于翻译起始因子 (eIF) 4G 家族蛋白的活性，该家族蛋白作为支架蛋白，在起始步骤中协调其他 eIF 的活性，以将 40S 核糖体亚基募集到 mRNA 上。三十年来对蛋白质合成及其调控的研究提供了大量证据，支持了帽依赖性翻译起始的关键作用，其中涉及 eIF4G。然而，最近发现的在没有 eIF4G 的情况下启动翻译的各种令人惊讶的替代机制，动摇了人们对蛋白质合成如何进行的传统观点。这些机制涉及已知 eIF 之间的新相互作用，或者已知 eIF 与以前与翻译无关的其他蛋白质之间的新相互作用。因此，一幅新的画面正在出现，其中非常规的翻译起始复合物有助于调节真核生物基因表达的多种机制的多样性。
