Functional characterization of evolutionarily conserved DNA regions in Forkhead Box f1 gene locus
Functional characterization of evolutionarily conserved DNA regions in Forkhead Box f1 gene locus
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DOI：
10.1074/jbc.m506531200
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发表时间：
2005-11-11
影响因子：
4.8
通讯作者：
Kalinichenko, VV
中科院分区：
文献类型：
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作者：
Kim, IM;Zhou, Y;Kalinichenko, VV
Forkhead Box F1(Foxf1)转录因子(以前称为HfH-8或Freac-1)在横隔和内脏(内脏)中胚层表达，是肠源性器官正常发育所必需的。小鼠和人Foxf1基因的序列比较发现，高度保守的DNA序列位于-5.3kb的Foxf1启动子区域和位于Foxf1基因3‘端的400个核苷酸调控元件(3’RE)。为了检测它们在小鼠胚胎发育过程中的转录活性，我们建立了转基因小鼠，在转基因小鼠中，β-半乳糖苷酶转基因基因的表达受-2.7-kb的Foxf1启动子区域、-5.3-kb的Foxf1启动子区域或-5.3-kb的Foxf1启动子区域融合到3‘RE的控制。-5.3-kb的Foxf1启动子序列在中肠和发育中的肠道诱导了适当的转基因表达，而-2.7-kb的Foxf1启动子区域在转录上是不活跃的。在-5.3-kb的Foxf1启动子中加入3‘RE，恢复了前肠、肝脏和肺间充质中的正确转基因表达，并阻止了在发育中的神经系统中的异位转基因表达。共转染研究表明，FOXA2蛋白结合到3‘RE区(+4506/+4529bp)，并足以抑制-5.3-kb Foxf1启动子的表达。此外，C/EBPβ和HNF-6蛋白结合到3‘RE区(+4647/+4694bp)，并在共转染实验中提供了-5.3-kb Foxf1启动子的协同转录激活。这些研究表明，在小鼠胚胎发育过程中，保守的Foxf1 3‘RE区对Foxf1启动子区域的组织特异性调控是必不可少的。
The Forkhead Box f1 (Foxf1) transcription factor ( previously known as HFH-8 or Freac-1) is expressed in the septum transversum and splanchnic ( visceral) mesoderm and is required for proper development of gut-derived organs. Sequence comparisons of mouse and human Foxf1 genes have revealed highly conserved DNA sequences located within the -5.3-kb Foxf1 promoter region and the 400-nucleotide regulatory element located 1 kb 3' to the Foxf1 gene (3'RE). To examine their transcriptional activity during mouse embryonic development, we generated transgenic mice in which the expression of the beta-galactosidase transgene was controlled by the - 2.7- kb Foxf1 promoter region, the - 5.3-kb Foxf1 promoter region, or the - 5.3-kb Foxf1 promoter region fused to the 3' RE. The - 5.3-kb Foxf1 promoter sequences induced appropriate transgene expression in the midgut and developing intestine, whereas the - 2.7-kb Foxf1 promoter region was transcriptionally inactive. Addition of 3' RE to the - 5.3-kb Foxf1 promoter restored proper transgene expression in the foregut, liver, and lung mesenchyme and prevented ectopic transgene expression in the developing nervous system. Cotransfection studies demonstrated that FoxA2 protein bound to the 3' RE region (+ 4506/+4529 bp) and was sufficient to inhibit expression of the -5.3-kb Foxf1 promoter. Furthermore, C/EBP beta and HNF-6 proteins bound to the 3' RE region (+ 4647/ + 4694 bp) and provided synergistic transcriptional activation of the - 5.3-kb Foxf1 promoter in cotransfection assays. These studies demonstrated that the conserved Foxf1 3' RE region is essential for proper tissue-specific regulation of the Foxf1 promoter region during mouse embryogenesis.