人类TREX-2和mRNP重塑中的相关复合体对DDX39B调节的结构机制
Bradley P Clarke1, Shengyan Gao2, Menghan Mei1
1Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, USA.
Nature communications
|July 2, 2025
概括
一个新的核复合体,TREX-2.1,从信使核糖核蛋白粒子 (mRNP) 中释放DDX39B (UAP56). 这一发现澄清了DDX39B在mRNP加工和核出口中的功能周期.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 基因表达规范 基因表达规范
背景情况:
- 核出口信使核糖核蛋白颗粒 (mRNP) 对于真核生物的基因表达至关重要.
- 死亡盒ATPaseDDX39B (UAP56) 是核mRNP的关键调节者,但其在mRNP组装和出口控制中的确切作用尚未完全理解.
研究的目的:
- 阐明DDX39B调解mRNP组装和出口的机制.
- 确定在mRNP处理过程中参与DDX39B活动调节的新因素.
主要方法:
- 低温电子显微镜 (Cryo-EM) 用于确定TREX-2.1/DDX39B和TREX-2/DDX39B复合物的结构.
- 用RNA测序来分析LENG8淘汰对mRNA种群的影响.
- 新型TREX-2.1复合物的生物化学特征.
主要成果:
- 一个新型核复合物的识别,TREX-2.1,由LENG8,PCID2和DSS1.1组成.
- 冷-EM结构揭示了对DDX39B调节至关重要的LENG8 (TREX-2.1) 和GANP (TREX-2) 中的保存触发循环.
- LENG8 knockdown 影响高GC含量mRNAs的一个子集的核细胞质比,表明其在mRNA出口调节中的作用.
结论:
- 这些发现为DDX39B的功能循环提供了机械的理解.
- TREX-2.1和TREX-2复合体调节DDX39B活动,控制mRNP处理和核出口.
- LENG8是TREX-2.1的关键组成部分,影响特定mRNA的出口.
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