Hox transcription factor Antp regulates sericin-1 gene expression in the terminal differentiated silk gland of Bombyx mori
Hox transcription factor Antp regulates sericin-1 gene expression in the terminal differentiated silk gland of Bombyx mori
复制标题
DOI：
10.1016/j.ydbio.2013.12.002
复制
发表时间：
2014-02-01
影响因子：
2.7
通讯作者：
Takiya, Shigeharu
中科院分区：
文献类型：
--
作者：
Kimoto, Mai;Tsubota, Takuya;Takiya, Shigeharu
Hox基因是动物发育形态发生沿着前后轴的主要调控基因。然而，Hox蛋白调节其靶基因并决定细胞命运的分子机制尚未完全了解。家蚕丝腺是一个沿丝腺前后轴沿着分为若干亚区的管状组织，丝素基因表达具有特定的模式。丝氨酸蛋白酶1基因（ser 1）在中部丝腺（MSG）中表达，具有亚局部特异性。在这里，我们表明，Hox蛋白Antp是一个组成部分的中间丝腺特异性复合物，MIC（味精-intermolt-特异性复合物），结合到ser 1的基本启动子元件，并激活其表达。Antp在转基因家蚕中的异位表达诱导了ser 1在后部丝腺（PSG）中的表达，而在前部丝腺（MSG-A）中不表达。相应地，通过在PSG提取物中加入重组Antp及其辅因子Exd和Hth形成MIC样复合物，但在MSG-A提取物中不形成。在PSG中，由Antp的异位表达诱导的ser 1 mRNA的剪接模式几乎与MSG中的那些在5龄时相同，并且根据Antp的诱导时间而改变。其他Hox基因在丝腺中以亚局部特异性表达。Hox丝腺可能为理解Hox蛋白如何选择和调节其靶基因提供了一个有用的系统。(C)2013 Elsevier Inc. All rights reserved.
Hox genes are well-known master regulators in developmental morphogenesis along the anteroposterior axis of animals. However, the molecular mechanisms by which Hox proteins regulate their target genes and determine cell fates are not fully understood. The silk gland of Bombyx mori is a tubular tissue divided into several subparts along the anteroposterior axis, and the silk genes are expressed with specific patterns. The sericin-1 gene (ser1) is expressed in the middle silk gland (MSG) with sublocal specificity. Here we show that the Hox protein Antp is a component of the middle silk gland-specific complex, MIC (MSG-intermolt-specific complex), binds to the essential promoter element of ser1, and activates its expression. Ectopic expression of Antp in transgenic silkworms induced the expression of ser1 in the posterior silk gland (PSG), but not in the anterior part of MSG (MSG-A). Correspondingly, a MIC-like complex was formed by the addition of recombinant Antp in extracts from PSG with its cofactors Exd and Hth, but not in extracts from MSG-A. Splicing patterns of ser1 mRNA induced by the ectopic expression of Antp in PSG were almost the same as those in MSG at the fifth instar and altered depending on the induction timing of Antp. Other Hox genes were expressed with sublocal specificity in the silk gland. The Bombyx silk gland might provide a useful system for understanding how Hox proteins select and regulate their target genes. (C) 2013 Elsevier Inc. All rights reserved.