Chemistry Research Laboratory, Department of Chemistry, University of Oxford , Oxford, UK.
Tri-Service General Hospital, National Defense Medical Center , Taipei, Taiwan.
Epigenetics. 2021 Jan;16(1):14-27. doi: 10.1080/15592294.2020.1786305. Epub 2020 Jul 1.
Post-translational modifications (PTMs) to the tails of the core histone proteins are critically involved in epigenetic regulation. Hypoxia affects histone modifications by altering the activities of histone-modifying enzymes and the levels of hypoxia-inducible factor (HIF) isoforms. Synthetic hypoxia mimetics promote a similar response, but how accurately the hypoxia mimetics replicate the effects of limited oxygen availability on the levels of histone PTMs is uncertain. Here we report studies on the profiling of the global changes to PTMs on intact histones in response to hypoxia/hypoxia-related stresses using liquid chromatography-mass spectrometry (LC-MS). We demonstrate that intact protein LC-MS profiling is a relatively simple and robust method for investigating potential effects of drugs on histone modifications. The results provide insights into the profiles of PTMs associated with hypoxia and inform on the extent to which hypoxia and hypoxia mimetics cause similar changes to histones. These findings imply chemically-induced hypoxia does not completely replicate the substantial effects of physiological hypoxia on histone PTMs, highlighting that caution should be used in interpreting data from their use.
核心组蛋白尾部的翻译后修饰（PTM）在表观遗传调控中起着关键作用。缺氧通过改变组蛋白修饰酶的活性和缺氧诱导因子（HIF）亚型的水平来影响组蛋白修饰。合成缺氧模拟物可促进类似的反应，但这些缺氧模拟物在多大程度上能准确复制有限氧供应对组蛋白PTM水平的影响尚不确定。在此，我们报告了利用液相色谱 - 质谱联用（LC - MS）技术对完整组蛋白上PTM的全局变化进行分析，以研究缺氧/缺氧相关应激的研究。我们证明完整蛋白质LC - MS分析是一种相对简单且稳健的方法，用于研究药物对组蛋白修饰的潜在影响。这些结果为与缺氧相关的PTM谱提供了见解，并说明了缺氧和缺氧模拟物对组蛋白产生相似变化的程度。这些发现表明化学诱导的缺氧并不能完全复制生理缺氧对组蛋白PTM的显著影响，强调在解释使用它们的数据时应谨慎。
