Heterochromatin formation in mammalian cells: Interaction between histones and HP1 proteins
Heterochromatin formation in mammalian cells: Interaction between histones and HP1 proteins
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DOI：
10.1016/s1097-2765(01)00218-0
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发表时间：
2001-04-01
期刊：
影响因子：
16
通讯作者：
Losson, R
中科院分区：
文献类型：
--
作者：
Nielsen, AL;Oulad-Abdelghani, M;Losson, R
异染色质蛋白1（HP 1）家族的成员是沉默非组蛋白蛋白。在这里，我们表明，在P-19胚胎癌（EC）细胞核，HP 1 α，β和γ形式同源和异源聚体与核小体核心组蛋白。在体外，所有三个HP 1结合到有尾和无尾核小体，并与组蛋白H3的组蛋白折叠特异性相互作用。此外，HP 1 α与连接体组蛋白H1相互作用。HP 1 α分别通过其染色体结构域（CD）和铰链区与H3和H1结合。有趣的是，Polycomb（Pc 1/M33）CD也与H3相互作用，并且已知在果蝇中消除HP 1和Polycomb沉默的CD突变严重损害了HP 1 α和Pc 1/M33与H3的结合。这些结果定义了一个新的功能，保守的CD，并建议，HP 1的自我协会和组蛋白结合可能发挥至关重要的作用，在HP 1介导的异染色质组装。
Members of the heterochromatin protein 1 (HP1) family are silencing nonhistone proteins. Here, we show that in P-19 embryonal carcinoma (EC) nuclei, HP1 alpha, beta, and gamma form homo- and heteromers associated with nucleosomal core histones. In vitro, all three HP1s bind to tailed and tailless nucleosomes and specifically interact with the histone-fold of histone H3. Furthermore, HP1 alpha interacts with the linker histone H1. HP1 alpha binds to H3 and H1 through its chromodomain (CD) and hinge region, respectively. Interestingly, the Polycomb (Pc1/M33) CD also interacts with H3, and HP1 alpha and Pc1/M33 binding to H3 is severely impaired by CD mutations known to abrogate HP1 and Polycomb silencing in Drosophila. These results define a novel function for the conserved CD and suggest that HP1 self-association and histone binding may play a crucial role in HP1-mediated heterochromatin assembly.