Kelly Lisa E, Carrel Tessa L, Herman Gail E, El-Hodiri Heithem M
Center for Molecular and Human Genetics, Columbus Children's Research Institute, The Ohio State University, Columbus, OH 43205, USA.
Biochem Biophys Res Commun. 2006 Jun 9;344(3):1031-7. doi: 10.1016/j.bbrc.2006.03.235. Epub 2006 Apr 19.
Xenopus Zic3 (zinc finger in the cerebellum-3) is expressed in the dorsal neural tube of tailbud embryos and tadpoles. We have isolated a 3.1kb DNA fragment from the Xenopus laevis Zic3 locus that drives proper expression of a GFP reporter in transgenic frog tailbud embryos and tadpoles. This fragment contains regions that are highly similar among frogs, mice, and humans. One extremely conserved region contains a predicted Pbx binding site. We found that the transcription factors Pbx1b and Meis1 can bind this site and synergistically transactivate expression of a reporter containing the conserved region. Finally, we found that an intact Pbx site is essential for normal Zic3 promoter activity in transgenic frog embryos. Our data strongly suggest that a highly conserved region of the Zic3 promoter functions by direct interaction with Pbx1b and Meis1.
非洲爪蟾的Zic3（小脑锌指蛋白3）在尾芽胚胎和蝌蚪的背神经管中表达。我们从非洲爪蟾Zic3基因座分离出一个3.1kb的DNA片段，该片段可驱动绿色荧光蛋白（GFP）报告基因在转基因青蛙尾芽胚胎和蝌蚪中正常表达。这个片段包含在青蛙、小鼠和人类中高度相似的区域。一个高度保守的区域含有一个预测的Pbx结合位点。我们发现转录因子Pbx1b和Meis1可以结合该位点，并协同反式激活含有保守区域的报告基因的表达。最后，我们发现完整的Pbx位点对于转基因青蛙胚胎中正常的Zic3启动子活性至关重要。我们的数据强烈表明，Zic3启动子的一个高度保守区域通过与Pbx1b和Meis1直接相互作用发挥功能。
