目的:鉴定ezrin基因在HeLa细胞中的主要转录调控区,初步研究ezrin基因的转录调控机制。方法:采用嵌套缺失技术构建一系列以ezrin基因翻译起始位点上游不同长度DNA序列作为报告基因启动子的重组pGLB质粒,利用双荧光素酶报告基因分析系统检测启动子的转录活力,并利用在线分析程序预测ezrin基因主要转录调控区的潜在转录因子结合位点。结果:获得一系列含不同长度ezrin基因5′侧翼区序列的重组pGLB质粒;当ezrin基因5′侧翼区序列从-1324截短到-890时,转录活力降低约80%,从-146截短到-32时,转录活力几乎完全丧失;在-1324/-890和-146/-32区,存在大量的Sp1转录因子结合位点。结论:在HeLa细胞中,ezrin基因的-1324/-890和-146/-32区是主要的转录调控区。Sp1可能是调控基因转录的重要转录因子。
Objective:To identify key transcriptional regulatory regions of ezrin gene in HeLa cells, thus this work maked a preliminary study for revealing its transcriptional regulatory mechanism. Methods: The recombinant pGLB plasmids containing different lengths of DNA fragments upstream of translation initiation site of ezrin gene as reporter promoters were constructed using nested-deletion method, and the promoter activities were detected using dual-luciferase reporter assay system. The potential transcription factor binding sites at key transcriptional regulatory region of ezrin gene were predicted using on-line analyzing programme. Results: The recombinant pGLB plasmids containing different lengths of 5'-flanking region of ezrin gene were obtained. When the lengths of ezrin 5'-flanking region were reduced from -1 324 to -890, the transcriptional activity decreased by about 80%. If the length of 5'-flanking region were deleted from -146 to -32, the transcriptional activities were nearly abolished. Sp 1 transcriptional factor binding sites were ubiquitous at the -1 324/-890 and -146/-32 regions. Conclusion: The -1 324/-890 and -146/-32 regions were two key transcriptional regulatory regions of ezrin gene in HeLa cells. Sp 1 may be an important factor for regulating the transcription of ezrin gene.