Division of Chemistry and Chemical Engineering, 1200 E. California Blvd., MC 210-41, California Institute of Technology, Pasadena, CA 91125, USA.
Nucleic Acids Res. 2011 Apr;39(7):2981-94. doi: 10.1093/nar/gkq954. Epub 2010 Dec 11.
MicroRNAs (miRNAs) are prevalent regulatory RNAs that mediate gene silencing and play key roles in diverse cellular processes. While synthetic RNA-based regulatory systems that integrate regulatory and sensing functions have been demonstrated, the lack of detail on miRNA structure-function relationships has limited the development of integrated control systems based on miRNA silencing. Using an elucidated relationship between Drosha processing and the single-stranded nature of the miRNA basal segments, we developed a strategy for designing ligand-responsive miRNAs. We demonstrate that ligand binding to an aptamer integrated into the miRNA basal segments inhibits Drosha processing, resulting in titratable control over gene silencing. The generality of this control strategy was shown for three aptamer-small molecule ligand pairs. The platform can be extended to the design of synthetic miRNAs clusters, cis-acting miRNAs and self-targeting miRNAs that act both in cis and trans, enabling fine-tuning of the regulatory strength and dynamics. The ability of our ligand-responsive miRNA platform to respond to user-defined inputs, undergo regulatory performance tuning and display scalable combinatorial control schemes will help advance applications in biological research and applied medicine.
微小 RNA（miRNA）是普遍存在的调节 RNA，可介导基因沉默，并在多种细胞过程中发挥关键作用。虽然已经证明了整合调节和感应功能的合成 RNA 基调控系统的存在，但由于 miRNA 结构-功能关系的细节有限，基于 miRNA 沉默的集成控制系统的发展受到了限制。我们利用 Drosha 加工与 miRNA 基本片段单链性质之间已阐明的关系，开发了一种设计配体响应 miRNA 的策略。我们证明，配体与整合到 miRNA 基本片段中的适体结合会抑制 Drosha 加工，从而实现对基因沉默的可滴定控制。该控制策略的通用性已在三个适体-小分子配体对中得到证明。该平台可扩展到合成 miRNA 簇、顺式作用 miRNA 和自我靶向 miRNA 的设计，这些 miRNA 既能在顺式作用又能在反式作用，从而可以精细调节调节强度和动力学。我们的配体响应 miRNA 平台能够响应用户定义的输入、进行调节性能调整并显示可扩展的组合控制方案的能力将有助于推进生物研究和应用医学中的应用。
