马铃薯X病毒外壳蛋白的表达水平与变偶密码子使用频率的相关性  

Relativity Betweeen Expression Level of Potato Virus X Coat Protein and the Codon Usage of Wobble Codon

作　　者：冯德江[1] 蔡华雅[1] 刘翔[1] 徐军望[1] 朱祯[1] 

机构地区：[1]中国科学院遗传与发育生物学研究所,北京100101

出　　处：《微生物学报》2003年第5期569-576,共8页Acta Microbiologica Sinica

基　　金：国家"973项目"(G2 0 0 0 0 162 0 5 );国家自然科学基金重点资助项目 (3 99890 0 1)~~

摘　　要：把经密码子修饰的马铃薯X病毒 (PotatoVirusX ,PVX)外壳蛋白 (CoatProtein,CP)基因和未修饰的野生型外壳蛋白基因与CaMV 3 5S启动子融合后 ,构建成相应的植物表达载体 ,利用农杆菌介导转化烟草。分别对修饰CP和野生CP的转基因烟草进行Westernblot和ELISA分析 ,结果表明经密码子修饰的PVX外壳蛋白的表达量是野生型蛋白表达量的 1 3～1 5。Northernblot结果表明修饰和未修饰的外壳蛋白在转录水平上是一致的。以上结果暗示外源基因中稀有密码子的数量可能是限制外源基因表达的一个因素。The relationship between the quantities of rare codons and the expression levels of foreign genes is very important in gene engineering. But up to now, there is few experiment on it in multicellular eukaryotes, especially in plants. To stud y the effect of rare codons on the expression level of potato virus X(PVX) coat protein(CP) in transgenic tobacco, some preferred codons in PVX coat protein gen e were substituted with synonymous rare codons without changing the encoded amin o acid sequence using site-specific mutation. The modified coat protein gene( cpm) and non-modified coat protein gene(cpw) were inserted into binary ve ctor under the control of CaMV35S promoter, and these two plant expression const ructs were transferred into tobacco(Nicotiana tabacum cv. Xanthi) genomes via Agrobacterium mediated method and transgenic plants were generated. Wester n blot and ELISA of these transgenic tobaccos showed that the expression level o f modified CP is about one third to one sixth of that of non-modified CP. North ern blot analysis of RNAs from some transfor- mants indicated that the tra nscripti onal levels of cpm are the same as that of cpw, which implicated that t he quantity of rare codons in foreign gene was a possible limited factor in fore ign gene expre- ssion process. Changing the quantity of rare codons maybe an effective method for organism to control gene expression.ctorunderthecontrolofCaMV35Spromoter,and thesetwoplantexpressionconstructsweretransferredintotobacco(Nicot

关 键 词：马铃薯X病毒 外壳蛋白 表达水平 变偶密码子 基因修饰 基因表达 

分 类 号：S432.41[农业科学—植物病理学] S435.32[农业科学—农业昆虫与害虫防治]