干扰素诱导RIG-G基因表达调控机制研究  

Study on mechanisms of the expression regulation of interferon-induced gene

作　　者：李冬[1,2] 肖澍[1] 潘晓蓉[1] 楼叶江[1] 贾培敏[1] 童建华[1] 

机构地区：[1]上海交通大学医学院附属瑞金医院上海血液学研究所,200025 [2]同济大学附属同济医院检验科

出　　处：《中华医学遗传学杂志》2007年第6期625-628,共4页Chinese Journal of Medical Genetics

基　　金：国家自然科学基金（30570778,30670882）;国家973计划（2002cB512805）;国家863计划（2006AA02219A）;上海市教委曙光计划（2003年）;上海交通大学医学院骨干师资计划（2003年）

摘　　要：目的探讨α干扰素（interferon α,IFNα）调控维甲酸诱导基因（retinoic acid-inducedgene G,RIG-G）表达的分子机制。方法应用http：//www.gene-regulation.com网站提供的AliBaba2.1软件对RIG-G基因的启动子区域进行分析,并采用荧光素酶报告基因转染实验和凝胶电泳迁移实验检测RIG-G基因启动子的功能活性及其对IFNα的反应性。结果发现在RIG-G基因的启动子序列中包含2个保守的干扰素刺激反应元件（IFN-stimulated response elements,ISREs）。转录因子STAT1蛋白（signal transducer and activator of tran-scription1）能够与这两个反应元件ISREⅠ和ISREⅡ相互结合。此外,在HT1080细胞中,与空载pXP2报告基因相比,含有ISREⅠ和ISREⅡ的pXP2-A报告基因表现出很强的基础活性（1741.2±517.5）,且这种活性还可被IFNα增强3～4倍（5338.7±1226.9,P〈0.05）。而在STAT1缺陷的U3A细胞中,pXP2-A报告基因的活性则被明显消弱（从1741.2±517.5降到406.1±103.2,P〈0.05）,加入IFNα也不能使其加强,表明STAT1蛋白是ISREⅠ和ISREⅡ发挥活性所必需的。结论RIG-G基因启动子所包含的ISREs是IFNα诱导RIG-G基因表达的分子基础,RIG-G是一个受STAT1蛋白直接调控的靶基因,在IFNα的信号转导途径中发挥着重要的作用。Objective To investigate the molecular mechanisms of the expression regulation of retinoic acidinduced gene G （R/G-G） by interferon α （IFNα）. Methods R/G-G promoter region was analysed by bioinformatics. The functional activities of R/G-G promoter with or without IFNα were detected by luciferase reporter assay and electrophoretic mobility shift assay （EMSA）. Results R/G-G promoter region contained two well-conserved IFN-stimulated response elements （ISREs）. Both ISRE Ⅰ and ISRE Ⅱ showed their effective binding abilities with signal transducer and activator of transcription 1 （STAT1）. In HT1080 cells, in contrast with the empty plasmidp XP2, pP2-A reporter construct containing intact ISRE Ⅰ and ISRE Ⅱ showed a significant higher baseline expression （1741.2 ± 517.5） which could be further enhanced up to three-four folds by IFNα （5338.7 ± 1226.9, P 〈 0.05）. However, the luciferase activity of pXP2-A as well as its IFNα inducibility could be abrogated in STATl-deficient U3A cells （from 1741.2 ± 517. 5 to 406.1 ± 103.2, P 〈 0.05）, indicating that the STAT1 protein was a prerequisite for the activities of ISRE I and ISRE 11 . Conclusion ISREs present in R/G-G promoter region are molecular basis of IFNα-induced R/G-G expres- sion. R/G-G is a target gene directly regulated by STAT1 protein and should play a key role in IFN α signaling pathways.

关 键 词：维甲酸诱导基因 Α干扰素 表达调控 STAT1蛋白 干扰素刺激反应元件 

分 类 号：R686[医药卫生—骨科学]