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为研究白细胞介素2受体α亚基（IL-2Rα）基因中与负调控元件NRE（-391/-381bp）呈反向重复的序列NIRS（-153/-143bp）在该基因表达中的作用,通过检测Jurkat细胞及HeLa细胞中荧光素酶报告基因活性,发现NIRS与NRE不仅共同阻遏IL-2Rα基因的组成性表达,还共同参与介导PHA对该基因启动子的诱导活性.EMSA检测显示,激活前后的Jurkat细胞及HeLa细胞中均含有双链NIRS和双链NRE的结合蛋白;HeLa细胞中还含有与这两个序列结合的单链结合蛋白;但是,激活前后的Jurkat细胞抽提物分别加入HeLa细胞抽提物与单链DNA的结合体系中均能产生超迁移现象,其中活化细胞抽提物呈现较强的迁移结合带.紫外交联实验检测发现,在激活前后的Jurkat细胞和HeLa细胞中均存在双链DNA结合蛋白p83.结果显示,不同细胞中,反式作用因子能通过NRE和/或NIRS元件以及单、双链DNA的选择性对IL-2Rα基因启动子活性起关键调控作用.
In order to investigate the role of NIRS (-153 / -143bp), an inverted repeat of the negative regulatory element NRE (-391 / -381bp), in the gene of the interleukin 2 receptor alpha subunit (IL-2Rα) By detecting the luciferase reporter gene activity in Jurkat cells and HeLa cells, we found that NIRS and NRE not only constrain the constitutive expression of IL-2Rα gene, but also participate in the mediation of PHA inducing activity of this gene promoter. Showed that both Jurkat cells and HeLa cells before and after activation contained binding proteins of double-stranded NIRS and double-stranded NRE; HeLa cells also contained a single-stranded binding protein binding to both sequences; however, Jurkat cells before and after activation were extracted Were added to HeLa cell extracts and single-stranded DNA binding system can produce super-migration phenomenon, in which the activated cell extract showed a strong migration of binding bands.Ultraviolet crosslinking experiments showed that before and after activation of Jurkat cells And double-stranded DNA binding protein p83 in HeLa cells.The results showed that trans-acting factors in different cells could activate IL-2Rα gene promoter activity through NRE and / or NIRS elements and single and double-stranded DNA selectivity The essential Control role.