Identification and characterization of the minimal promoter of Mipu1: the role of GC boxes in the regulation of basal transcription
Identification and characterization of the minimal promoter of Mipu1: the role of GC boxes in the regulation of basal transcription
复制标题
Mipu1最小启动子的鉴定和表征：GC盒在基础转录调控中的作用
DOI：
10.1093/abbs/gmp019
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发表时间：
2009-04-01
影响因子：
3.7
通讯作者：
Xiao, Xianzhong
中科院分区：
文献类型：
--
作者：
Lv, Ben;Tang, Yiting;Xiao, Xianzhong
Mipu1是一个编码KRAB/C2H2锌指蛋白的新基因，首次被报道在心肌缺血再灌注损伤中上调，起到保护细胞免受氧化应激的作用。为了定位该基因的启动子区域并了解其调控，我们确定了该基因的转录起始点，发现位于该转录起始点上游的1366-bp片段具有启动子活性。Mipu1 5‘侧翼区的缺失结构导致了一个最小启动子的鉴定，其中既没有检测到TATA盒，也没有检测到CAAT盒。发现了两个GC盒，但它们是Sp1家族转录因子的特异性结合部位。这些GC盒的突变导致Mipu1最小启动子活性的完全丧失。最后，Sp1家族特异性抑制剂WP631以剂量依赖的方式降低启动子活性，表明GC盒对于Mipu1最低启动子活性是必不可少的。
Mipu1, a novel gene encoding a KRAB/C2H2 zinc-finger protein, was first reported to be up-regulated in myocardial ischemia-reperfusion injury, functioning to protect cells against oxidative stress. To map the promoter region of the gene and to understand its regulation, we identified the transcription start site and revealed that the 1366-bp fragment upstream of the transcription start site possesses promoter activity. Deletion constructs of the 5 '-flanking region of Mipu1 lead to the identification of a minimal promoter, in which neither a TATA box nor a CAAT box was detected. Two GC boxes were found; however, they are the specific binding sites for Sp1-family transcription factors. Mutations in these GC boxes resulted in the total loss of Mipu1 minimal promoter activity. Finally, WP631, an Sp1-family-specific inhibitor, was found to decrease the promoter activity in a dose-dependent manner, indicating that the GC boxes are essential for the activity of the Mipu1 minimal promoter activity.