基因素H2A中的谷氨胺甲基化是一种RNA-聚合酶I专用修饰
Peter Tessarz1, Helena Santos-Rosa1, Sam C Robson1
11] Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK [2] Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK.
Nature
|December 20, 2013
概括
研究人员发现了一种新的组素修饰,H2A的谷氨酸甲基化,对于调节核糖体DNA转录至关重要. 这种表观遗传标记特别针对RNA聚合酶I,并影响FACT复合体与核细胞的相互作用.
科学领域:
- 表观遗传学和分子生物学
- 染色体生物学 染色体生物学
- 核细胞功能 核细胞功能
背景情况:
- 核细胞体经历多种多样的翻译后修改,影响DNA过程.
- 基因组蛋白修饰是基因表达和染色质结构的关键调节者.
研究的目的:
- 为了识别和表征一种新型的组织蛋白修饰:谷氨胺甲基化.
- 确定负责这种修饰的酶及其细胞局部.
- 阐明谷氨胺甲基化在调节DNA转录中的功能作用.
主要方法:
- 在酵母和人体细胞中鉴定基因组H2A上的谷氨胺甲基化.
- 使用酵母遗传学 (Nop1) 和人类正义分析 (fibrillarin) 来识别酶.
- 针对特定检测H2A Q105甲基化 (H2AQ105me) 的抗体生成.
- 染色体免疫沉和体外结合试验以研究FACT复杂相互作用.
主要成果:
- 鉴定出一种新的组织蛋白修饰,即谷氨胺甲基化 (酵母H2A中的Q105).
- 诺1和纤维拉林被分别确定为酵母和人类细胞中的甲基转移酶.
- 这种修饰仅在核细胞中,在35S核糖体DNA (rDNA) 位点上得到丰富.
- H2A Q105甲基化调节了基因伴奏组合FACT复合物的结合.
- 在Q105或FACT组件中的突变改变了基因素结合和rDNA转录.
结论:
- 胺甲基化H2A是第一个特定于RNA聚合酶I的基因素标记.
- 这种表观遗传标记调节了与核细胞的FACT复杂相互作用.
- 它在控制核中的核体DNA转录和染色质动力学方面发挥着关键作用.
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