确定成熟的微RNA/小干扰RNA和微RNA之间的定义长度
GeunYoung Sim1,2, Audrey C Kehling3, Mi Seul Park3
1Center for RNA Biology, The Ohio State University, Columbus, OH, 43210, USA.
Scientific reports
|November 13, 2023
概括
阿尔戈纳特 (AGO) 蛋白质将微RNA (miRNA) 和小干扰RNA (siRNA) 加载到RNA诱导的沉默复合体 (RISC). 导向长度会影响RISC构造,因为tinyRNAs (tyRNAs) 可能会因未定3'端而与目标发生不同的相互作用.
科学领域:
- 分子生物学分子生物学
- 在RNA生物学,RNA生物学.
- 生物化学 生物化学
背景情况:
- 微RNAs (miRNAs) 和小干扰RNAs (siRNAs) 与Argonaute (AGO) 蛋白质组合在一起,形成RNA诱导的沉默复合体 (RISC).
- RISC组装涉及向导细分为种子,中心,3'补充和尾部区域,这些区域对于目标识别至关重要.
- 导向RNA的3'端与AGO PAZ域结,但由于模两可的miRNA处理,这种构造所需的最小长度尚不清楚.
研究的目的:
- 为了确定维持RISC结构所需的最小指导RNA长度.
- 调查导向RNA序列是否影响PAZ域固的最小长度要求.
- 探索较短的导向RNAs的功能影响,称为tinyRNAs (tyRNAs).
主要方法:
- 使用3'到5'外核酶,ISG20,精确地缩短与AGO相关的miR-20a和let-7a.
- 测量了指导RNA的长度,其3'端不再到达PAZ域.
- 将miR-20a和let-7a所需的长度进行比较,以保持RISC的符合性.
主要成果:
- miR-20a 需要 19 个核酸 (nt),let-7a 需要 20 nt 才能保持 RISC 形状.
- 不同的长度表明了序列特异性相互作用,特别是PAZ域对于let-7a中的第19位置上的腺的低亲和力.
- 确定了17-nt指南足够短,可以作为tyRNAs发挥作用,具有未定的3'端.
结论:
- 对于RISC形状的最小导向长度是依赖于序列的,受导向的尾部区域和PAZ域亲和力的影响.
- 与未定3'端的TinyRNAs (tyRNAs) 缺乏标准指导细分,与miRNAs和siRNAs相比,可以通过不同的机制识别目标.
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