Phosphorylation of TET proteins is regulated via O-GlcNAcylation by the O-linked N-acetylglucosamine transferase (OGT).
Phosphorylation of TET proteins is regulated via O-GlcNAcylation by the O-linked N-acetylglucosamine transferase (OGT).
复制标题
DOI：
10.1074/jbc.m114.605881
复制
发表时间：
2015-02-20
期刊：
影响因子：
--
通讯作者：
Leonhardt H
中科院分区：
文献类型：
--
作者：
Bauer C;Göbel K;Nagaraj N;Colantuoni C;Wang M;Müller U;Kremmer E;Rottach A;Leonhardt H
背景：泰特蛋白氧化5-甲基胞嘧啶并促进活性DNA去甲基化。结果：O-连接GlcNAc转移酶用GlcNAc修饰泰特蛋白，从而减少泰特磷酸化。结论：泰特蛋白质在低复杂性区域受到翻译后修饰的动态相互作用。重要性：这是第一张泰特磷酸化和O-GlcNAc化位点的氨基酸解析图，为今后泰特调控的研究提供了宝贵的资源。泰特蛋白将5-甲基胞嘧啶氧化为5-羟甲基胞嘧啶、5-甲酰基胞嘧啶和5-羧基胞嘧啶，从而为哺乳动物中的主动DNA去甲基化提供了可能的手段。虽然它们的催化机制被很好地表征，并且催化双加氧酶结构域是高度保守的，但调节区（N末端和双加氧酶结构域的两个部分之间的低复杂性插入物）的功能仅知之甚少。在这里，我们证明了泰特蛋白受到各种翻译后修饰，主要发生在这些调控区域。我们绘制了泰特修饰位点的氨基酸分辨率，并首次显示TET 1，TET 2和TET 3高度磷酸化。O-连接的GlcNAc转移酶，我们确定为与所有三种泰特蛋白的强相互作用物，催化将GlcNAc基团添加到泰特蛋白的丝氨酸和苏氨酸残基，从而减少磷酸化位点的数量和位点占用。有趣的是，不同的泰特蛋白显示独特的翻译后修饰模式，并且一些修饰以不同的组合发生。总之，我们的研究结果提供了一种新的潜在机制，泰特蛋白调控的基础上的动态相互作用的磷酸化和O-GlcNAc在N端和低复杂性插入区域。我们的数据表明，由于环境条件的变化以及对外部刺激的响应，修饰位点之间存在强烈的串扰，这可以使泰特蛋白定位、活性或靶向快速适应。
Background: TET proteins oxidize 5-methylcytosine and contribute to active DNA demethylation. Results: O-Linked GlcNAc transferase modifies TET proteins with GlcNAc and thereby reduces TET phosphorylation. Conclusion: TET proteins are subjected to a dynamic interplay of post-translational modifications at low-complexity regions. Significance: This first map of TET phosphorylation and O-GlcNAcylation sites at amino acid resolution provides a valuable resource for future studies of TET regulation. TET proteins oxidize 5-methylcytosine to 5-hydroxymethylcytosine, 5-formylcytosine, and 5-carboxylcytosine and thus provide a possible means for active DNA demethylation in mammals. Although their catalytic mechanism is well characterized and the catalytic dioxygenase domain is highly conserved, the function of the regulatory regions (the N terminus and the low-complexity insert between the two parts of the dioxygenase domains) is only poorly understood. Here, we demonstrate that TET proteins are subject to a variety of post-translational modifications that mostly occur at these regulatory regions. We mapped TET modification sites at amino acid resolution and show for the first time that TET1, TET2, and TET3 are highly phosphorylated. The O-linked GlcNAc transferase, which we identified as a strong interactor with all three TET proteins, catalyzes the addition of a GlcNAc group to serine and threonine residues of TET proteins and thereby decreases both the number of phosphorylation sites and site occupancy. Interestingly, the different TET proteins display unique post-translational modification patterns, and some modifications occur in distinct combinations. In summary, our results provide a novel potential mechanism for TET protein regulation based on a dynamic interplay of phosphorylation and O-GlcNAcylation at the N terminus and the low-complexity insert region. Our data suggest strong cross-talk between the modification sites that could allow rapid adaption of TET protein localization, activity, or targeting due to changing environmental conditions as well as in response to external stimuli.