A novel Sp1-related cis element involved in intestinal alkaline phosphatase gene transcription.
A novel Sp1-related cis element involved in intestinal alkaline phosphatase gene transcription.
复制标题
一种参与肠道碱性磷酸酶基因转录的新型 Sp1 相关顺式元件。
DOI：
10.1152/ajpgi.1999.276.4.g800
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Hodin,RA
中科院分区：
文献类型：
--
作者：
Kim,JH;Meng,S;Shei,A;Hodin,RA
我们利用丁酸钠处理的HT-29细胞作为体外模型系统，研究肠道碱性磷酸酶（IAP）基因激活的分子机制。利用人内联cat报告基因和dna酶I足迹进行瞬时转染，定位了序列5 ‘ -GACTGGGCGGGGTCAAGATGGA-3 ’对应的关键元件（IF-III）。IF-III元件的缺失导致报告基因活性的显著降低，并且IF-III被证明在异源（SV40）启动子中以细胞类型特异性的方式起作用，进一步支持其在IAP转激活中的功能作用。电泳迁移率转移分析显示，IF-III结合Sp1和Sp3，但这些因素只占总核结合的一部分，似乎只介导其转录活性的一小部分。IF-III不对应于任何先前表征的来自其他肠道特异性基因的调节区域。因此，我们在人类IAP基因中发现了一个新的sp1相关调控元件，该元件在体外分化过程中似乎在其转录激活中发挥作用。
We have used sodium butyrate-treated HT-29 cells as an in vitro model system to study the molecular mechanisms underlying intestinal alkaline phosphatase (IAP) gene activation. Transient transfection assays using human IAP-CAT reporter genes along with DNase I footprinting were used to localize a criticalciselement (IF-III) corresponding to the sequence 5′-GACTGGGCGGGGTCAAGATGGA-3′. Deletion of the IF-III element resulted in a dramatic reduction in reporter gene activity, and IF-III was shown to function in the context of a heterologous (SV40) promoter in a cell type-specific manner, further supporting its functional role in IAP transactivation. Electrophoretic mobility shift assays revealed that IF-III binds Sp1 and Sp3, but these factors comprise only a portion of the total nuclear binding and appear to mediate only a small portion of its transcriptional activity. IF-III does not correspond to any previously characterized regulatory region from other intestine-specific genes. We have thus identified a novel, Sp1-relatedcis-regulatory element in the human IAP gene that appears to play a role in its transcriptional activation during differentiation in vitro.