Center for Gene Regulation in Health and Disease, Department of Biological, Geological and Environmental Sciences, Cleveland State University, Cleveland, OH 44115, USA.
Gene. 2012 Jul 10;502(2):75-86. doi: 10.1016/j.gene.2012.04.039. Epub 2012 Apr 24.
Studies over the past 5 or so years have indicated that the traditional clustering of mechanisms for translation initiation in eukaryotes into cap-dependent and cap-independent (or IRES-mediated) is far too narrow. From individual studies of a number of mRNAs encoding proteins that are regulatory in nature (i.e. likely to be needed in small amounts such as transcription factors, protein kinases, etc.), it is now evident that mRNAs exist that blur these boundaries. This review seeks to set the basic ground rules for the analysis of different initiation pathways that are associated with these new mRNAs as well as related to the more traditional mechanisms, especially the cap-dependent translational process that is the major route of initiation of mRNAs for housekeeping proteins and thus, the bulk of protein synthesis in most cells. It will become apparent that a mixture of descriptions is likely to become the norm in the near future (i.e. m(7)G-assisted internal initiation).
过去 5 年左右的研究表明，真核生物中传统的翻译起始机制聚类为帽依赖性和帽非依赖性（或 IRES 介导）过于狭隘。从对许多编码具有调节性质的蛋白质的 mRNA（即可能需要少量的转录因子、蛋白激酶等）的个别研究中，现在显然存在模糊这些界限的 mRNA。本综述旨在为与这些新 mRNA 相关的不同起始途径的分析设定基本规则，以及与更传统的机制（特别是帽依赖性翻译过程）相关的规则，该过程是管家蛋白 mRNA 起始的主要途径，因此也是大多数细胞中蛋白质合成的大部分。很明显，在不久的将来，可能会出现混合描述的情况（即 m(7)G 辅助的内部起始）。
