通过HUSH介导的无内部移动元件的沉默来监测基因组
Marta Seczynska1, Stuart Bloor1, Sergio Martinez Cuesta2
1Cambridge Institute for Therapeutic Immunology and Infectious Disease, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, UK.
Nature
|November 18, 2021
概括
人类沉默枢纽 (HUSH) 复合体通过准内无基因元素来识别和沉默入侵的DNA,如逆转录病毒. 这种机制可以保护基因组免受外来DNA的影响.
科学领域:
- 遗传学
- 分子生物学
- 表观遗传学
背景情况:
- 细胞拥有对入侵DNA的防御机制,使用压制性染色质修饰来限制转录.
- 人类沉默枢纽 (HUSH) 综合体已知可以通过H3K9me3通过转录抑制长间隔的元素-1逆转子 (L1s) 和逆转病毒.
- 通过HUSH识别和启动这些外来遗传元素的确切机制尚不清楚.
研究的目的:
- 阐明HUSH复合体如何识别和启动入侵基因元素的转录抑制.
- 调查内核在HUSH中介抑制中的作用.
- 了解HUSH复合体的基因组监控系统及其区分外来DNA与宿主基因的能力.
主要方法:
- 使用一系列长,无内基的转基因来测试HUSH识别和抑制能力.
- 研究了内部插入对HUSH中介抑制的影响,即使没有拼接.
- 使用H3K9me3沉积分析和基因组数据来绘制HUSH结合和抑制目标.
主要成果:
- HUSH识别并通过转录抑制各种长,无内基因的转基因.
- 在独立于拼接的情况下,Intron插入会对抗HUSH抑制.
- 在H3K9me3沉积之前,HUSH结合了目标转录,目标转录对H3K9me3的启动和传播至关重要.
- HUSH抑制来自细胞逆转移mRNA的内源性无基因子集.
结论:
- 无中子cDNA是HUSH的关键特征,可以从宿主基因中区分入侵的反元素.
- HUSH作为一种依赖转录的基因组监控系统,可立即对新型外来DNA提供保护.
- 这种系统有效地保护基因组免受"非自我"DNA的影响,同时防止内源基因的不适当抑制.
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