Architectural and Functional Diversity of Polycomb Group Response Elements in Drosophila
Architectural and Functional Diversity of Polycomb Group Response Elements in Drosophila
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DOI：
10.1534/genetics.113.153247
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发表时间：
2013-10-01
期刊：
影响因子：
3.3
通讯作者：
Kassis, Judith A.
中科院分区：
文献类型：
--
作者：
Brown, J. Lesley;Kassis, Judith A.
果蝇多梳组反应元件（PREs）在多梳组（PcG）阻遏蛋白的基因调控中起着重要作用。PRE是PcG蛋白募集和维持阻遏所必需的。PRE由多种DNA结合蛋白的结合位点组成，但目前尚不清楚PRE活性所需的结合位点组合。在这里，我们比较的结合位点和活动的两个紧密相连，但可分离的果蝇enrailed（en）基因，PRE 1和PRE 2的前。PRE 1和PRE 2都含有多个PRE-DNA结合蛋白的结合位点，但这两个PREs之间的位点的数量、排列和间隔不同。PRE 1和PRE 2都介导配对敏感的沉默mini-white，PcG抑制的功能测定;然而，PRE 1需要两个结合位点的Pleiohameotic（Pho），而PRE 2只需要一个Pho结合位点的活动。此外，对于完整的配对敏感性沉默活性，PRE 1需要在PRE 2中未发现的富含AT的区域。这两种PRE在PRE胚胎和幼虫报告基因构建体中的不同表现，所述报告基因构建体插入基因组中的相同位置。我们的数据说明了PRE的结构和功能的多样性。
Polycomb group response elements (PREs) play an essential role in gene regulation by the Polycomb group (PcG) repressor proteins in Drosophila. PREs are required for the recruitment and maintenance of repression by the PcG proteins. PREs are made up of binding sites for multiple DNA-binding proteins, but it is still unclear what combination(s) of binding sites is required for PRE activity. Here we compare the binding sites and activities of two closely linked yet separable PREs of the Drosophila engrailed (en) gene, PRE1 and PRE2. Both PRE1 and PRE2 contain binding sites for multiple PRE-DNA-binding proteins, but the number, arrangement, and spacing of the sites differs between the two PREs. These differences have functional consequences. Both PRE1 and PRE2 mediate pairing-sensitive silencing of mini-white, a functional assay for PcG repression; however, PRE1 requires two binding sites for Pleiohomeotic (Pho), whereas PRE2 requires only one Pho-binding site for this activity. Furthermore, for full pairing-sensitive silencing activity, PRE1 requires an AT-rich region not found in PRE2. These two PREs behave differently in a PRE embryonic and larval reporter construct inserted at an identical location in the genome. Our data illustrate the diversity of architecture and function of PREs.