针对小沉默RNA的目标RNA指导的修剪和尾巴
Stefan L Ameres1, Michael D Horwich, Jui-Hung Hung
1Howard Hughes Medical Institute and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
概括
微RNAs (miRNAs) 和目标信使RNAs (mRNAs) 之间广泛的互补性触发了Drosophila中的miRNA尾巴和修剪. 这个过程被2-O-甲基化阻断,这解释了动物miRNA调节中的部分互补性.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 在RNA生物学,RNA生物学.
背景情况:
- 微RNA (miRNA) 和小干扰RNA (siRNA) 是真核生物中基因表达的关键调节者.
- 在Drosophila中,Argonaute1 (Ago1) 结合miRNAs进行信使RNA (mRNA) 抑制,而Argonaute2 (Ago2) 结合siRNAs进行核酸防御.
- 与siRNA不同,miRNAs通常表现出与其mRNA目标的部分互补性.
研究的目的:
- 调查miRNA及其标之间的差异互补性背后的机制.
- 了解阿尔戈诺特蛋白和小RNA修饰在目标识别和调节中的作用.
- 阐明目标互补对小RNA稳定性和处理的影响.
主要方法:
- 对Drosophila中与Argonaute蛋白结合的小RNA种群的分析.
- 生物化学测试以评估小RNA尾部,修剪和2'-O-甲基化.
- 在野生类型和突变中进行的功能研究缺乏关键RNA修饰酶,如Hen1.1.
- 在人体细胞中进行实验,以研究保存机制.
主要成果:
- 在Argonaute1结合的miRNA及其目标mRNA之间存在广泛的互补性,导致miRNA的尾巴和3'-to-5'-trimming.
- 中的Argonaute2结合的小RNA在它们的3'末端有2'-O-甲基化,这种修饰在Argonaute1结合的小RNA中不存在.
- 这种由Hen1酶进行的2'-O-甲基化阻止了Argonaute2-结合的小RNA的目标定向重塑.
- 在没有Hen1的情况下,Argonaute2相关的siRNAs会经历尾巴和修剪,类似于miRNAs.
- 目标互补性影响人体细胞中小RNA的稳定性,这表明保留了调节原则.
结论:
- 广泛的目标互补性触发了与Argonaute1结合的miRNAs的特定处理,包括尾巴和修剪.
- 与Argonaute2结合的小RNA的3'-end 2'-O-甲基化作为阻止这种重塑事件的关键修改.
- 这些发现解释了动物miRNA及其mRNA标之间观察到的特征性的部分互补性,突出了复杂的调节机制.
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