Brule Christina E, Grayhack Elizabeth J
Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA; Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA.
Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14642, USA; Center for RNA Biology, University of Rochester, Rochester, NY 14642, USA.
Trends Genet. 2017 Apr;33(4):283-297. doi: 10.1016/j.tig.2017.02.001. Epub 2017 Mar 12.
The genetic code, which defines the amino acid sequence of a protein, also contains information that influences the rate and efficiency of translation. Neither the mechanisms nor functions of codon-mediated regulation were well understood. The prevailing model was that the slow translation of codons decoded by rare tRNAs reduces efficiency. Recent genome-wide analyses have clarified several issues. Specific codons and codon combinations modulate ribosome speed and facilitate protein folding. However, tRNA availability is not the sole determinant of rate; rather, interactions between adjacent codons and wobble base pairing are key. One mechanism linking translation efficiency and codon use is that slower decoding is coupled to reduced mRNA stability. Changes in tRNA supply mediate biological regulationfor instance,, changes in tRNA amounts facilitate cancer metastasis.
遗传密码定义了蛋白质的氨基酸序列，同时也包含影响翻译速率和效率的信息。密码子介导的调控机制和功能都尚未得到很好的理解。普遍的模型是，由稀有tRNA解码的密码子的缓慢翻译会降低效率。最近的全基因组分析已经阐明了几个问题。特定的密码子和密码子组合会调节核糖体速度并促进蛋白质折叠。然而，tRNA的可用性并不是速率的唯一决定因素；相反，相邻密码子之间的相互作用和摆动碱基配对才是关键。一种将翻译效率与密码子使用联系起来的机制是，较慢的解码与降低的mRNA稳定性相关联。tRNA供应的变化介导生物调控，例如，tRNA数量的变化促进癌症转移。
