Regulation of photoreceptor gene expression by the retinal homeobox (Rx) gene product
Regulation of photoreceptor gene expression by the retinal homeobox (Rx) gene product
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DOI：
10.1016/j.ydbio.2009.12.032
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发表时间：
2010-03-15
影响因子：
2.7
通讯作者：
El-Hodiri, Heithem M.
中科院分区：
文献类型：
--
作者：
Pan, Yi;Martinez-De Luna, Reyna I.;El-Hodiri, Heithem M.
视网膜同源盒（Rx）基因产物对眼睛发育至关重要。然而，对其分子功能知之甚少。已经证明Rx结合到光感受器保守元件（PCE-1），其是在光感受器特异性基因（例如视紫红质和红锥视蛋白）的启动子区中发现的高度保守元件。我们验证了Rx与成熟的光感受器中的视紫红质和红锥视蛋白共表达，并证明Rx在体内与视紫红质和红锥视蛋白启动子结合。我们还发现，Rx可以与非洲爪蟾类似物的Crx和Nrl，otx 5 b和XLMaf（分别），激活非洲爪蟾视蛋白启动子依赖性报告。最后，我们表明，减少Rx在蝌蚪中的表达的结果在几个PCE-1含有感光基因的表达减少，感光细胞形态异常，视力受损。我们的数据表明，Rx，与其他转录因子相结合，是必要的正常感光基因的表达，维护和功能。这确立了Rx在调节分化细胞类型中表达的基因中的直接作用。(C)2009 Elsevier Inc. All rights reserved.
The retinal homeobox (Rx) gene product is essential for eye development. However little is known about its molecular function. It has been demonstrated that Rx binds to photoreceptor conserved element (PCE-1), a highly conserved element found in the promoter region of photoreceptor-specific genes such as rhodopsin and red cone opsin. We verify that Rx is co-expressed with rhodopsin and red cone opsin in maturing photoreceptors and demonstrate that Rx binds to the rhodopsin and red cone opsin promoters in vivo. We also find that Rx can cooperate with the Xenopus analogs of Crx and Nrl, otx5b and XLMaf (respectively), to activate a Xenopus opsin promoter-dependent reporter. Finally, we demonstrate that reduction of Rx expression in tadpoles results in decreases in expression of several PCE-1 containing photoreceptor genes, abnormal photoreceptor morphology, and impaired vision. Our data suggests that Rx, in combination with other transcription factors, is necessary for normal photoreceptor gene expression, maintenance, and function. This establishes a direct role for Rx in regulation of genes expressed in a differentiated cell type. (C) 2009 Elsevier Inc. All rights reserved.