Characterization of the 5'-flanking region of the murine polymeric IgA receptor gene.
Characterization of the 5'-flanking region of the murine polymeric IgA receptor gene.
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鼠聚合 IgA 受体基因 5 侧翼区域的表征。
DOI：
10.1152/ajpgi.1998.275.4.g778
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Tsai,AH
中科院分区：
文献类型：
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作者：
Martín,MG;Wang,J;Li,TW;Lam,JT;Gutierrez,EM;Solorzano-Vargas,RS;Tsai,AH
控制多聚伊加受体基因（pIgR）的基础和激活转录表达的调控元件尚未确定。在这项研究中，我们进行了功能分析的murinepIgR 5 ′-上游区。瞬时转染研究确定该基因的最小启动子位于转录起始上游110个核苷酸内。该区域的置换突变鉴定出一个假定的激活因子（−78至−70）和一个阻遏因子（−66至−52）。DNA酶I足迹分析证实了从-85到-62核苷酸的保护区域。假定区域的迁移率变化分析证实了上游刺激因子1（USF 1）与E盒元件在−75和−70位置的结合，代表了假定的增强子。使用各种形式的USF的过表达研究表明USF 1和USF 2都增强pIgR最小启动子的活性。我们报告的murinepIgRminimal启动子的鉴定和表征，以及USF在提高其在Caco-2细胞中的基础转录水平中的关键作用。
The regulatory elements that control basal and activated transcriptional expression of the polymeric IgA receptor gene (pIgR) have not been defined. In this study, we performed functional analysis of the murinepIgR5′-upstream region. Transient transfection studies identified the gene’s minimal promoter to reside within 110 nucleotides upstream from the start of transcription. Substitution mutations of this region identified both a putative activator (−78 to −70) and a repressor (−66 to −52) element. DNase I footprint analysis confirmed an area of protection that spans from nucleotides −85 to −62. Mobility shift assays of the putative region confirmed binding of upstream stimulatory factor 1 (USF1) to an E box element at positions −75 and −70, representing the putative enhancer. Overexpression studies using various forms of USF suggest that both USF1 and USF2 enhance activity of thepIgRminimal promoter. We report the identification and characterization of the murinepIgRminimal promoter, as well as the critical role of USF in enhancing its basal level of transcription in Caco-2 cells.