Pan Zhong-Zong, Kronenberg Mark S, Huang Dah-Yeou, Sumoy Lauro, Rogina Blanka, Lichtler Alexander C, Upholt William B
Department of BioStructure and Function, School of Medicine, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, Connecticut 06030, USA.
Biochem Biophys Res Commun. 2002 Jan 25;290(3):955-61. doi: 10.1006/bbrc.2001.6294.
The apical ectodermal ridge (AER) is a specialized ectodermal region essential for limb outgrowth. Msx2 expression patterns in limb development strongly suggest an important role for Msx2 in the AER. Our previous studies identified a 348-bp fragment of the chicken Msx2 gene with AER enhancer activity. In this study, the functions of four potential homeodomain binding TAAT sites in this enhancer were studied using transgenic mice and in vitro protein-DNA interactions. Transgenic studies indicate that the four TAAT sites are not redundant and that only the B-TAAT site is critical for AER enhancer activity. The expression patterns of Msx2 and Dlx5 genes in the AER suggest that they might be involved in the regulation of Msx2. In support of this hypothesis, we found that Msx2 and Dlx5 can bind to the B-TAAT site as well as to a fragment containing the D- and E-TAAT sites in the Msx2 AER enhancer sequences. (c)2002 Elsevier Science (USA).
顶端外胚层嵴（AER）是肢体生长所必需的一个特殊外胚层区域。Msx2在肢体发育中的表达模式强烈表明Msx2在AER中起重要作用。我们之前的研究鉴定出鸡Msx2基因的一个具有AER增强子活性的348 bp片段。在本研究中，利用转基因小鼠和体外蛋白质-DNA相互作用研究了该增强子中四个潜在的同源结构域结合TAAT位点的功能。转基因研究表明这四个TAAT位点并非冗余，且只有B-TAAT位点对AER增强子活性至关重要。Msx2和Dlx5基因在AER中的表达模式表明它们可能参与Msx2的调控。为支持这一假说，我们发现Msx2和Dlx5能够结合到B-TAAT位点以及Msx2 AER增强子序列中包含D-和E-TAAT位点的片段上。（c）2002爱思唯尔科学出版社（美国）
