Kuchino Y, Muramatsu T
Biophysics Division of National Cancer Center Research Institute, Tokyo, Japan.
Biochimie. 1996;78(11-12):1007-15. doi: 10.1016/s0300-9084(97)86724-7.
Mammalian cells contain suppressor tRNAs that can translate nonsense codons such as UAG and UGA localized at a specific site of natural mRNAs. For translation of these nonsense codons, a specific secondary or tertiary structure of mRNAs located in the region surrounding the translatable nonsense codon is required. In mammalian cells, transcriptional expression of the tRNA gene encoding UAG suppressor glutamine tRNA is repressed by the binding of a nuclear protein to a specific site in the 5'-flanking region of the gene. Based on these findings, we discuss the translational regulation of nonsense codons in mammalian mRNAs.
哺乳动物细胞含有抑制性tRNA，其能够翻译位于天然mRNA特定位点的无义密码子，如UAG和UGA。为了翻译这些无义密码子，需要位于可翻译无义密码子周围区域的mRNA具有特定的二级或三级结构。在哺乳动物细胞中，编码UAG抑制性谷氨酰胺tRNA的tRNA基因的转录表达通过一种核蛋白与该基因5'-侧翼区域中特定位点的结合而受到抑制。基于这些发现，我们讨论了哺乳动物mRNA中无义密码子的翻译调控。
