Serine 298 Phosphorylation in Linker 2 of UHRF1 Regulates Ligand-Binding Property of Its Tandem Tudor Domain
Serine 298 Phosphorylation in Linker 2 of UHRF1 Regulates Ligand-Binding Property of Its Tandem Tudor Domain
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DOI：
10.1016/j.jmb.2020.05.006
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发表时间：
2020-06-26
影响因子：
5.6
通讯作者：
Arita, Kyohei
中科院分区：
文献类型：
--
作者：
Kori, Satomi;Jimenji, Tomohiro;Arita, Kyohei
带有PhD和RING指域的泛素样蛋白1(Uhrf1)是维持哺乳动物DNA甲基化的一个重要因素，并含有几个识别表观遗传标记的阅读器模块。Uhrf1的串联Tudor结构域(TTD)具有多肽结合槽，可作为分子内或分子间相互作用的结合平台。除了与uhrf1的非磷酸化连接物2和间隔区相互作用外，它还在Lys9处与二三甲基化组蛋白H3相互作用，在Lys126处与DNA连接酶1(LIG1)相互作用。在这里，我们重点研究连接子2中Ser298的磷酸化，这意味着调节TTD的配体结合特性。虽然uhrf1的蛋白表达水平在整个细胞周期中没有变化，但Ser298磷酸化形式的uhrf1在G2/M期显著增加，免疫沉淀和Western blotting显示这一点。在分子上，当未磷酸化的连接体2覆盖多肽结合槽以阻止其他相互作用体进入时，小角X射线散射、热稳定性分析和分子动力学模拟表明Ser298的磷酸基团将连接体2从TTD的多肽结合槽中解离出来，从而允许其他相互作用体进入连接槽。我们的数据揭示了连接物2中Ser298的磷酸化触发TTD结构改变的机制，并可能通过促进DNA复制位点的LIG1和异色素区的组蛋白H3K9me2/ME3的结合来影响uhrf1的多种功能。(C)2020爱思唯尔有限公司。保留所有权利。
Ubiquitin-like with PHD and RING finger domains 1 (UHRF1) is an essential factor for the maintenance of mammalian DNA methylation and harbors several reader modules for recognizing epigenetic marks. The tandem Tudor domain (TTD) of UHRF1 has a peptide-binding groove that functions as a binding platform for intra- or intermolecular interactions. Besides the groove interacting with unphosphorylated linker 2 and spacer of UHRF1, it also interacts with di/tri-methylated histone H3 at Lys9 and DNA ligase 1 (LIG1) at Lys126. Here we focus on the phosphorylation of Ser298 in linker 2, which was implied to regulate the ligand-binding property of the TTD. Although the protein expression level of UHRF1 is unchanged throughout the cell cycle, Ser298 phosphorylated form of UHRF1 is notably increased in the G2/M phase, which is revealed by immunoprecipitation followed by Western blotting. Molecularly, while unphosphorylated linker 2 covers the peptide-binding groove to prevent access of other interactors, small-angle X-ray scattering, thermal stability assay and molecular dynamics simulation revealed that the phosphate group of Ser298 dissociates linker 2 from the peptide-binding groove of the TTD to permit the other interactors to access to the groove. Our data reveal a mechanism in which Ser298 phosphorylation in linker 2 triggers a change of the TTD's structure and may affect multiple functions of UHRF1 by facilitating associations with LIG1 at DNA replication sites and histone H3K9me2/me3 at heterochromatic regions. (C) 2020 Elsevier Ltd. All rights reserved.