人SCF基因5′旁侧-1190～- 853 AT富集区功能研究

Characterization of the AT Rich Region from -1190 to -853 of 5′ Flanking Sequence of Human Stem Cell Factor Gene

已有的报告基因和EMSA实验研究表明 ,人干细胞生长因子 (SCF)基因 5′旁侧AT富集区- 1 1 90～ - 853在HeLa和MCF 7细胞中均能增强下游基因转录 ,可能为一个核基质结合区(MAR) ,对人SCF基因的转录发挥调控作用 .为进一步研究该AT富集区的功能 ,将人SCF基因 5′旁侧 - 1 1 90～ - 853AT富集区分别克隆入SV40或CMV启动子前后紧接着CAT报告基因 ,瞬时转染Jurkat,HepG2和 3T3细胞 ,检测CAT报告基因的瞬时表达活性 .结果表明 :人SCF基因 5′旁侧- 1 1 90～ - 853AT富集区在Jurkat和HepG2细胞中 ,对分别由SV40和CMV启动子引导的CAT基因表达均有抑制作用 ;但在 3T3细胞中对SV40启动子的转录活性表现出增强作用 ,对CMV启动子的转录活性无明显影响 .这些结果提示 ,人SCF基因 5′旁侧 - 1 1 90～ - 853AT富集区转录调控具有组织细胞特异性 。

It was shown that the AT rich region from -1190 to -853 of 5′ flanking sequence of human stem cell factor (SCF)gene could enhance the transcription in both HeLa and MCF 7 cells by reporter gene and EMSA studies,as it might be a matrix associated region(MAR).The AT rich region from -1 190 to -853 of 5′ flanking sequence of human SCF gene was cloned upstream to SV40 or CMV promoter linked to a CAT reporter gene.Transient transfection experiments were performed to detect the expressional activites of CAT reporter gene in Jurkat,HepG2 and 3T3 cells.The results showed that the AT rich region from -1 190 to -853 of 5′ flanking sequence of the human SCF could significantly inhibit the activities of both promoters in Jurkat and HepG2;while it could improve the activity of SV40 promoter,and had little effect on the activity of CMV promoter in 3T3 cell.The results indicated that the AT rich region from -1190 to -853 of 5′ flanking sequence of the human SCF had a tissue specific regulatory function,it might suppress or improve the transcriptional activities of promoters in different cells.