Recruitment of Drosophila Polycomb group proteins to chromatin by DSP1
Recruitment of Drosophila Polycomb group proteins to chromatin by DSP1
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DOI：
10.1038/nature03386
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发表时间：
2005-03-24
期刊：
影响因子：
64.8
通讯作者：
Cavalli, G
中科院分区：
文献类型：
--
作者：
Déjardin, J;Rappailles, A;Cavalli, G
Polycomb 和 trithorax 组（PcG 和 trxG）蛋白在整个发育过程中分别保持沉默和活跃转录状态 (1)。在果蝇中，PcG 和 trxG 蛋白与名为 Polycomb 和 trithorax 反应元件（PRE 和 TRE）的 DNA 区域相关，但募集机制尚不清楚。我们之前描述了 Abdominal-B 基因调控区的一个最小元件，称为 Ab-Fab。 Ab-Fab 包含 PRE 和 TRE，能够在发育过程中维持抑制或活跃染色质状态 (2)。在这里，我们展示了背开关蛋白 1 (DSP1)（果蝇 HMGB2 同源物）与 Ab-Fab 和其他特征性 PRE 中存在的序列结合。将此基序添加到包含多同质异型和 GAGA 因子共有位点的人工序列中足以在体内招募 PcG 蛋白。废除 DSP1 与 Ab-Fab 和来自 engrailed 位点的 PRE 结合的突变会导致 PcG 蛋白结合丧失、沉默丧失以及这些 PRE 转变为组成型 TRE。因此，DSP1 与 PRE 的结合对于 PcG 蛋白的募集非常重要。
Polycomb and trithorax group (PcG and trxG) proteins maintain silent and active transcriptional states, respectively, throughout development(1). In Drosophila, PcG and trxG proteins associate with DNA regions named Polycomb and trithorax response elements (PRE and TRE), but the mechanisms of recruitment are unknown. We previously characterized a minimal element from the regulatory region of the Abdominal-B gene, termed Ab-Fab. Ab-Fab contains a PRE and a TRE and is able to maintain repressed or active chromatin states during development(2). Here we show that the Dorsal switch protein 1 (DSP1), a Drosophila HMGB2 homologue, binds to a sequence present within Ab-Fab and in other characterized PREs. Addition of this motif to an artificial sequence containing Pleiohomeotic and GAGA factor consensus sites is sufficient for PcG protein recruitment in vivo. Mutations that abolish DSP1 binding to Ab-Fab and to a PRE from the engrailed locus lead to loss of PcG protein binding, loss of silencing, and switching of these PREs into constitutive TREs. The binding of DSP1 to PREs is therefore important for the recruitment of PcG proteins.