Translation Efficiency in Upstream Region of microRNA Targets in Arabidopsis thaliana.
Translation Efficiency in Upstream Region of microRNA Targets in Arabidopsis thaliana.
复制标题
拟南芥中 microRNA 靶标上游区域的翻译效率
DOI：
10.4137/ebo.s10362
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Zhou T
中科院分区：
文献类型：
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作者：
Gu W;Zhai C;Wang X;Xie X;Parinandi G;Zhou T
对于位于蛋白质编码序列的microRNA （miRNA）靶位上游区域，实验研究表明，罕见密码子而非频繁密码子对miRNA功能更重要，因为它们减缓了局部翻译过程。但是，miRNA靶点附近是否存在翻译效率降低的趋势尚不清楚。利用拟南芥，我们对miRNA靶点上游区域的同义密码子使用进行了全基因组分析。在全基因组水平上，我们没有发现翻译效率降低的显著选择信号。然而，相同的基因组分析确实显示了miRNA靶点之间翻译效率降低的实质性变化。我们发现miRNA的保护水平、基因密码子的使用偏差以及miRNA的作用机制可以解释翻译效率的差异。而基因GC含量、基因表达水平、miRNA靶点保存水平对miRNA靶点的局部翻译效率没有影响。尽管拟南芥miRNA靶点上游区域的局部翻译效率与miRNA功能有关，但该区域稀有密码子使用的选择信号较弱。我们认为，当miRNA靶点位于蛋白质编码序列中时，其他一些生物学因素在miRNA的作用中比局部翻译效率更重要。
With respect to upstream regions of microRNA (miRNA) target sites located in protein coding sequences, experimental studies have suggested rare codons, rather than frequent codons, are important for miRNA function, because they slow down the local translational process. But, whether there is a trend of reduced translation efficiency near miRNA targets is still unknown. Using Arabidopsis thaliana, we perform genome-wide analysis of synonymous codon usage in upstream regions of miRNA target sites. At the whole genome level, we find no significant selection signals for decreased translational efficiency. However, the same genome analyses do show substantial variations of translation efficiency reduction among miRNA targets. We find that miRNA conservation level, gene codon usage bias, and the mechanism of miRNA action can account for the differences in translation efficiency. But gene's GC content, gene expression level, and miRNA target's conservation level have no effect on local translation efficiency of miRNA targets. Although local translation efficiency in the upstream region of miRNA targets is related to miRNA function in A. thaliana, the selection signal of rare codon usage in that region is weak. We propose some other biological factors are more important than local translation efficiency in miRNA action when miRNA targets are located in protein coding sequences.