在DNA复制应激过程中,FMRP和DHX9之间的复杂相互作用
Arijita Chakraborty1, Arijit Dutta2, Leonardo G Dettori1
1Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, USA.
The Journal of biological chemistry
|December 18, 2023
概括
脆弱的X信使核糖蛋白 (FMRP) 缺乏导致通过阻止R循环的分辨率导致DNA双链断裂. 在FMRP中使用FMRP.
科学领域:
- 分子生物学分子生物学
- 遗传学 遗传学是一种遗传学.
- 细胞生物学 细胞生物学
背景情况:
- 脆弱X综合征 (FXS) 与FMRP缺乏有关,导致智力障碍.
- 目前尚不完全了解FMRP的核功能,特别是DNA修复和R循环调节方面的功能.
- FXS细胞在R循环易发生的部位呈现增加的DNA双链断裂 (DSB),特别是在复制应激下.
研究的目的:
- 调查FMRP和DHX9.9之间的相互作用.
- 阐明FMRP在调节DHX9活动和R循环分辨率中的作用.
- 了解FMRP突变如何影响蛋白质定位和DNA损伤.
主要方法:
- 同免疫沉以评估FMRP-DHX9相互作用.
- 试验室中螺旋酶测定测量FMRP的DHX9活性抑制.
- 染色素免疫沉以分析蛋白质在染色素上的持久性.
- 在具有和没有FMRP的细胞中分析R环相关的DSB.
主要成果:
- FMRP通过其氨基末端域直接与RNA基酶DHX9相互作用.
- FMRP在RNA:DNA混合体上抑制DHX9基酶活性,这种影响取决于氨基末端.
- 与FXS相关的FMRP I304N突变降低了FMRP-DHX9的相互作用,并在复制应激期间导致长期的FMRP和DHX9在染色质上.
- FMRP的缺失或功能障碍导致未解决的R循环和增加的DSBs.
结论:
- FMRP和DHX9在染色质上具有对抗性关系,这对于解决R循环至关重要.
- 适当的FMRP-DHX9相互作用有助于它们从已解决的R循环中解离.
- FMRP 缺陷或突变会破坏这种平衡,导致 R 循环积累和 DNA 损伤,从而导致 FXS 发病.
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