在聚合酶中活动切换的结构基础决定了let-7前miRNAs的命运
Gangshun Yi1,2, Mingda Ye3, Loic Carrique1
1Division of Structural Biology, Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
Nature structural & molecular biology
|July 25, 2024
概括
终端尿基转移酶TUT7和TUT4调节了let-7微RNA (miRNA) 的成熟或降解. 多能因子LIN28A指导TUT7/4添加多个尿素,影响细胞命运和癌症.
科学领域:
- 分子生物学分子生物学
- 在RNA生物学,RNA生物学.
- 结构生物学 结构生物学
背景情况:
- 瘤抑制者let-7前微RNAs (miRNAs) 是基因表达的关键调节者.
- 终端尿基转移酶TUT7和TUT4通过尿化控制小RNA处理.
- 作为一种RNA结合的多能性因子,LIN28A会影响TUT7/4活动和miRNA前尿解.
研究的目的:
- 为了阐明TUT7/4介导的前-miRNA尿化背后的结构机制.
- 了解LIN28A在指导单体与小体uridylation中的作用.
- 揭示这些过程如何调节细胞命运并导致癌症.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定高分辨率结构.
- 对单独的TUT7的活性形式,带有前-miRNA的TUT7和带有前-miRNA和LIN28A的TUT7/4捕获了结构.
- 分析的重点在于在LIN28A.的存在和缺席下,预微RNA的独特结合方式.
主要成果:
- 高分辨率的冷EM结构揭示了TUT7/4,前miRNA和LIN28A之间的分子相互作用.
- 预微RNA与TUT7/4的结合基本上是基于LIN28A的存在而有所不同.
- LIN28A充当紧剂,通过 TUT7/4.4 实现过程性橄-尿基化.
结论:
- 这项研究揭示了由LIN28A.指定的TUT7/4对差异性尿化 (单相反的Oligo-) 的分子基础.
- LIN28A与TUT和前-miRNAs的相互作用是调节let-7 miRNA处理的关键.
- 这些发现提供了关于细胞命运调节和癌症发展的机制的见解,其中涉及let-7/LIN28A/TUT通路.
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