异体化基H4的半合成揭示了染色体对分子衰老的强度和脆弱性
Tianze Zhang1, Luis F Guerra1, Yana Berlina2
1Department of Chemistry, King's College London, Britannia House, 7 Trinity Street, London SE1 1DB, U.K.
Journal of the American Chemical Society
|February 3, 2025
概括
蛋白质老化可能导致酸 (Asp) 形成异酸 (isoAsp). 在位置24 (H4isoD24) 的Histon H4进行了研究. H4isoD24会影响组织蛋白甲基化,但不会影响染色体的紧缩或重塑.
科学领域:
- 生物化学
- 分子生物学
- 表观遗传学
背景情况:
- 蛋白质通过自发的,非酶的翻译后修饰 (PTM) 进行衰老.
- 从酸 (Asp) 或氨酸残留物中形成异酸 (isoAsp) 是长寿命蛋白中常见的PTM.
- 具有较长半衰期的基因组容易产生异,从而影响染色体的结构和功能.
研究的目的:
- 在基因素H4中研究异酸 (isoAsp) 的分子后果.
- 使用蛋白质半合成生成和表征24位 (H4isoD24) 的全长基因组H4变体.
- 评估H4isoD24对染色体紧缩,核细胞重塑和基因组甲基化的影响.
主要方法:
- 用蛋白质半合成制造H4isoD24变体.
- 组装了含有H4isoD24的染色体模板.
- 使用体外测试来评估Mg2+介导的染色体自我关联,Chd1的核细胞重塑和Set8和Suv4-20h1的H4K20甲基化.
主要成果:
- H4isoD24没有显著地破坏Mg2+介导的染色体自我关联.
- 通过重塑剂Chd1的核细胞重定位在很大程度上不受H4isoD24的存在的影响.
- 在H4K20中,H4isoD24显著抑制了由Set8和Suv4-20h1催化的甲基化.
结论:
- 基因组H4中的异酸修饰导致染色体功能格局的复杂重组.
- 像压缩和重塑这样的宏观色素过程对H4isoD24具有强度.
- 局部机制,特别是H4K20甲基化,对组织蛋白中异酸修饰的存在很脆弱.
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