哺乳动物5'-caped微RNA前体,产生一个单一的微RNA
Mingyi Xie1, Mingfeng Li2, Anna Vilborg1
1Department of Molecular Biophysics and Biochemistry, Howard Hughes Medical Institute, Boyer Center for Molecular Medicine, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA.
Cell
|December 24, 2013
概括
研究人员发现了微RNA (miRNA) 生物发生的新途径. 这种途径绕过了典型的处理,产生了用于基因沉默应用的特定3p-siRNA.
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RNAs (miRNAs) 是关键的基因调节器,通过涉及微处理器复合体和Dicer.的正规途径进行处理.
- 这一途径产生成熟的5p和3p小RNA复合体.
研究的目的:
- 为了识别和描述一个替代的miRNA生物发生路径.
- 研究微处理器独立的前-miRNA形成和处理的机制.
- 探索这种途径对新型基因沉默工具的潜力.
主要方法:
- 开发一种小型RNA Cap-seq方法,使用eIF4E.的cap-binding蛋白.
- 在小鼠细胞中,全基因组识别7-甲基瓜诺辛 (m(7) G) 封顶的前miRNAs.
- 对前-miRNA核细胞质出口和Dicer处理的分析.
主要成果:
- 发现微处理器独立的,由转录起始和终结部位产生的m(7) G-capped pre-miRNA.
- 确定PHAX-exportin 1作为这些上限前miRNA的出口途径.
- 证明在Dicer裂变后,只有3p-miRNA被有效地加载到Argonaute中,形成一个功能性的microRNP.
结论:
- 一个新的miRNA生物发生路径存在,在miRNA前合成,运输和指导链选择方面是不同的.
- 这种途径允许生成单个3p-siRNAs,与正规miRNAs不同.
- 这一发现使得设计shRNA表达结构能够通过单个3p-siRNA生产来实现向基因沉默.
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