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乙甲基在活跃转录起点上标记染色体
William J Lu-Culligan1,2, Leah J Connor1,2, Yixuan Xie3
1Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, USA.
Nature
|September 21, 2023
概括
研究人员发现了一种新的蛋白质修饰,Nε-乙-Nε-甲基 (Kacme),其中氨酸残留物既甲基化又乙基化. 这种在基因素H4上发现的双重修饰与活性染色体和基因表达有关.
科学领域:
- 分子生物学
- 表观遗传学
- 翻译后的修改
背景情况:
- 蛋白质上的氨酸残留物经历了转化后的修饰 (PTM),如乙化和甲基化,这对于调节染色素和基因表达至关重要.
- 这些PTM是治疗各种人类疾病的关键目标.
- 人们普遍认为氨酸甲基化和乙化在同一残留物中是相互排斥的.
研究的目的:
- 识别和表征一种新的细胞 lysine 残留物修饰,其中包括同时乙化和甲基化.
- 研究这种双重修饰在染色体生物学中的发生,调节和功能影响.
主要方法:
- 在细胞蛋白中识别Nε-乙-Nε-甲基氨酸 (Kacme),特别是基因素H4 (H4Kacme).
- 在物种和哺乳动物组织中分析H4Kacme的存在.
- 测试以确定H4Kacme与活性染色体标记和转录活动的关联.
- 在H4Kacme形成和对脱乙的稳定性的体外酶研究.
- 使用与H4Kacme结合的BRD2蛋白的X射线晶体分析.
主要成果:
- 在各种物种和组织中发现Nε-乙-Nε-甲基 (Kacme),该残留物同时甲基化和乙化.
- H4Kacme与活性染色体标记相关,增强转录启动,对生物信号有反应.
- 可以通过酶形成H4Kacme并对某些脱乙酶表现出耐药性;其结构显示了像BRD2这样的乙素识别蛋白质的结合.
结论:
- Kacme是一种新型的翻译后修饰,有可能传递与分离甲基化或乙化不同的监管信息.
- 这些发现确立了Kacme在染色体生物学中的重要PTM,对理解基因调节有着根本性的影响.
- 这一发现为探索细胞过程和疾病中的素PTM复杂相互作用开辟了新的途径.
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