The bHLH factors Xath5 and XNeuroD can upregulate the expression of XBrn3d, a POU-homeodomain transcription factor
The bHLH factors Xath5 and XNeuroD can upregulate the expression of XBrn3d, a POU-homeodomain transcription factor
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DOI：
10.1006/dbio.2001.0178
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发表时间：
2001-04-15
影响因子：
2.7
通讯作者：
Vetter, ML
中科院分区：
文献类型：
--
作者：
Hutcheson, DA;Vetter, ML
碱性螺旋-环-螺旋（bHLH）因子Xath 5在过表达时促进视网膜神经节细胞分化，并且可以通过调节参与这些细胞分化的因子的表达来实现。潜在的候选者包括Brn 3 POU-同源域转录因子，其已经涉及视网膜神经节细胞发育。在这里，我们已经确定了一个新成员的Brn 3基因亚家族在非洲爪蟾，XBrn 3d。原位杂交分析显示XBrn 3d在视网膜的发育中的感觉神经元和发育中的神经节细胞中表达。使用激素诱导的Xath 5融合蛋白，我们已经证明在动物帽中Xath 5可以直接调节XBrn 3d的表达。由于XBrn 3d也在不表达Xath 5的感觉群体中表达，我们研究了bHLH因子XNeuroD对XBrn 3d表达的调节。XNeuroD-hGR融合蛋白类似地能够直接诱导动物帽中XBrn 3d的表达。此外，通过RNA注射过表达XBrn 3d促进了外侧外胚层中异位感觉神经元标记物的表达，表明其在调节神经元发育中的作用。因此，Xath 5和XNeuroD可以直接调节神经元亚型特异性因子的表达，提供神经元分化和细胞命运特化之间的联系。(C)北京：科学出版社.
The basic helix-loop-helix (bHLH) factor Xath5 promotes retinal ganglion cell differentiation when overexpressed and may do so by regulating the expression of factors involved in the differentiation of these cells. Potential candidates include the Brn3 POU-homeodomain transcription factors, which have been implicated in retinal ganglion cell development. Here we have identified a new member of the Brn3 gene subfamily in Xenopus, XBrn3d. In situ hybridization analysis shows XBrn3d expression in developing sensory neurons and developing ganglion cells of the retina. Using a hormone-inducible Xath5 fusion protein, we have shown that in animal caps Xath5 can directly regulate the expression of XBrn3d. Since XBrn3d is also expressed in sensory populations where Xath5 is not expressed, we examined the regulation of XBrn3d expression by the bHLH factor XNeuroD. A XNeuroD-hGR fusion protein is similarly able to directly induce the expression of XBrn3d in animal caps. In addition, overexpression of XBrn3d by RNA injection promotes the expression of ectopic sensory neuronal markers in the lateral ectoderm, suggesting a role in regulating neuronal development. Therefore, Xath5 and XNeuroD can directly regulate the expression of a neuronal subtype-specific factor, providing a link between neuronal differentiation and cell fate specification. (C) 2001 Academic Press.