Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, People's Republic of China.
Center for Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, People's Republic of China.
Philos Trans R Soc Lond B Biol Sci. 2023 Nov 20;378(1890):20220248. doi: 10.1098/rstb.2022.0248. Epub 2023 Oct 2.
Citrullination is a post-translational modification catalysed by peptidyl arginine deiminase (PAD) enzymes, and dysregulation of protein citrullination is involved in various pathological disorders. During the past decade, a panel of citrullination inhibitors has been developed, while small molecules activating citrullination have rarely been reported so far. In this study, we screened citrullination activator using an antibody against citrullinated histone H3 (cit-H3), and a natural compound demethoxycurcumin (DMC) significantly activated citrullination. The requirement of PAD2 for DMC-activated citrullination was confirmed by a loss of function assay. Notably, DMC directly engaged with PAD2, and showed binding selectivity among PAD family enzymes. Point mutation assay indicated that residue E352 is essential for DMC targeting PAD2. Consistently, DMC induced typical phenotypes of cells with dysregulation of PAD2 activity, including citrullination-associated cell apoptosis and DNA damage. Overall, our study not only presents a strategy for rationally screening citrullination activators, but also provides a chemical approach for activating protein citrullination. This article is part of the Theo Murphy meeting issue 'The virtues and vices of protein citrullination'.
瓜氨酸化是由肽基精氨酸脱亚氨酶（PAD）酶催化的翻译后修饰，蛋白质瓜氨酸化的失调与各种病理紊乱有关。在过去的十年中，已经开发出了一系列瓜氨酸化抑制剂，而迄今为止，很少有报道小分子激活瓜氨酸化的报道。在这项研究中，我们使用抗瓜氨酸化组蛋白 H3（cit-H3）抗体筛选瓜氨酸化激活剂，天然化合物脱甲氧基姜黄素（DMC）显著激活了瓜氨酸化。通过功能丧失测定证实了 PAD2 对 DMC 激活的瓜氨酸化的要求。值得注意的是，DMC 直接与 PAD2 结合，并在 PAD 家族酶中表现出结合选择性。点突变试验表明残基 E352 对于 DMC 靶向 PAD2 是必不可少的。一致地，DMC 诱导了 PAD2 活性失调的细胞的典型表型，包括瓜氨酸化相关的细胞凋亡和 DNA 损伤。总的来说，我们的研究不仅提出了一种合理筛选瓜氨酸化激活剂的策略，而且还提供了一种激活蛋白质瓜氨酸化的化学方法。本文是主题为“蛋白质瓜氨酸化的优缺点”的 Theo Murphy 会议特刊的一部分。
