人粒细胞集落刺激因子（hG－CSF）cDNA3′－UTR对其表达的影响

Effects of 3’-UTR on the Expression of hG-CSF cDNA

利用人粒细胞集落刺激因子（ｈＧ－ＣＳＦ）ｃＤＮＡ３′端非翻译区（３′－ＵＴＲ）中存在的ＤｒａⅠ酶切位点，通过部分酶切与完全酶切，删除３′－ＵＴＲ不同长度，构建了四种ｈＧ－ＣＳＦｃＤＮＡ瞬时重组表达质粒。转染ＣＯＳ－７细胞后，生物活性测定结果提示，ｈＧ－ＣＳＦｃＤＮＡ３′－ＵＴＲ对其表达起负调控作用，其关键性序列位于紧接终止密码子ＴＧＡ下游的６５ｂｐ范围内，３′－ＵＴＲ对ｈＧ－ＣＳＦｃＤＮＡ表达的影响与转录水平的差别有一定关系。

Four hG-CSF cDNA with different lengths of 3’-UTR recombinant transient expression plasmids were constructed through DraⅠcomplete and uncomplete digestion. After these expression plasmids were transfected into COS-7 cell line. Bioactivity assay indicated that 3’-UTR had an inhibitor effect on the expression of hG-CSF cDNA. The key codon responsible for that effect just located at 65bp sequence region downstream of the stop codon TGA. This effect may have some relations with the differences of transcriptional efficiency.