Zhang Jianming, Long Manyuan, Li Liming
Department of Ecology and Evolution, The University of Chicago, Chicago, IL 60637, USA.
Biochim Biophys Acta. 2005 May 1;1728(3):135-42. doi: 10.1016/j.bbaexp.2005.02.004. Epub 2005 Mar 2.
Evolved codon usages often pose a technical challenge over the expressing of eukaryotic genes in microbial systems because of changed translational machinery. In the present study, we investigated the translational effects of intragenic differential codon usage on the expression of the new Drosophila gene, jingwei (jgw), a chimera derived from two unrelated parental genes: Ymp and Adh. We found that jgw possesses a strong intragenic differential usage of synonymous codons, i.e. the Adh-derived C-domain has a significantly higher codon bias than that of the Ymp-derived N-domain (P=0.0023 by t-test). Additional evolutionary analysis revealed the heterogeneous distribution of rare codons, implicating its role in gene regulation and protein translation. The in vitro expression of jgw further demonstrated that the heterogeneous distribution of rare codons has played a role in regulating gene expression, particularly, affecting the quality of protein translation.
由于翻译机制的改变，进化后的密码子使用情况常常给在微生物系统中表达真核基因带来技术挑战。在本研究中，我们调查了基因内密码子差异使用对新的果蝇基因“经纬”（jgw）表达的翻译影响，“经纬”是一个源自两个不相关亲本基因Ymp和Adh的嵌合体。我们发现jgw在基因内同义密码子使用上存在强烈差异，即源自Adh的C结构域的密码子偏好性显著高于源自Ymp的N结构域（t检验P = 0.0023）。进一步的进化分析揭示了稀有密码子的异质分布，暗示了其在基因调控和蛋白质翻译中的作用。jgw的体外表达进一步证明，稀有密码子的异质分布在调节基因表达中发挥了作用，特别是影响了蛋白质翻译的质量。
