Huang W, Qiao T, Liu Z
Department of Moleculer Biology, Princeton University, USA.
Zhonghua Yi Xue Za Zhi. 1998 Oct;78(10):733-7.
To investigate the influence of adenovirus major late tripartite leader sequence on specific exportation of virus mRNA in the late phase of adenovirus infection.
We constructed a marked, human beta-actin minigene under the control of the glucocorticoid-inducible enhancer and promoter of mouse mammary tumor virus, and inserted it into the left end of the adenovirus type V genome. The promoter gene, designated MA, as well as of a sibling, which differed only in inclusion of a cDNA copy of the adenovirus major late tripartite leader sequence upstream of beta-actin sequences termed MtplA, in recombinant virus-infected cells was strictly dependent on addition of deoxymethesone to the medium. Nuclear and cytoplasmic reporter RNA species were compared by Northern blotting, primer extension and pulse-chase assay.
The high concentrations of newly-synthesized RNA were accumulated in cytoplasm when tripartite leader sequence was present in reporter RNA, despite the equal rates of transcription of the two reporter genes. Nuclear and cytoplasmic reporter RNA species compared by Northern blotting, primer extension, and pulse-chase provided no evidence for altered processing induced by tripartite leader sequence.
The tripartite leader sequence, known to facilitate translation of mRNA during the late phase of adenovirus infection, can also modulate mRNA export from the nucleus.
研究腺病毒主要晚期三联体前导序列对腺病毒感染后期病毒mRNA特异性输出的影响。
我们构建了一个在小鼠乳腺肿瘤病毒糖皮质激素诱导增强子和启动子控制下的标记人β-肌动蛋白小基因，并将其插入V型腺病毒基因组的左端。在重组病毒感染的细胞中，名为MA的启动子基因以及一个仅在β-肌动蛋白序列上游包含腺病毒主要晚期三联体前导序列的cDNA拷贝（称为MtplA）的同胞基因，其表达严格依赖于向培养基中添加地塞米松。通过Northern印迹、引物延伸和脉冲追踪试验比较核和细胞质中的报告RNA种类。
尽管两个报告基因的转录速率相同，但当报告RNA中存在三联体前导序列时，高浓度新合成的RNA在细胞质中积累。通过Northern印迹、引物延伸和脉冲追踪比较核和细胞质中的报告RNA种类，没有证据表明三联体前导序列会诱导加工改变。
已知在腺病毒感染后期促进mRNA翻译的三联体前导序列，也可以调节mRNA从细胞核的输出。
