Chemical Approaches to Control the Function of Regulatory RNAs

近几十年来，我们对RNA的看法发生了戏剧性的变化。而RNA最初被认为几乎不是 作为遗传信息从DNA转移到蛋白质的被动信使，现在很清楚的是，RNA是 一种令人兴奋和未被探索的调控分子，将继续带来生物学上的新发现 还有医学。我们的研究计划努力利用这些令人兴奋的未来发现，通过使用 通过化学修饰来调节结构和功能的调控RNA。长期目标是 1)为基础研究和生物医学应用开发新的RNA化学修饰，以及 2)探索序列特异性识别双链RNA的新模式。我们的研究 该计划包括两个不同但相互关联的项目：1)酰胺作为新的主干修饰，用于 调控RNA，以及2)修饰的肽核酸(PNA)对dsRNA的序列特异性识别。 项目1用酰胺键取代短干扰RNA和RNA中的核苷酸间磷酸 与成簇的规则间隔的短回文重复(CRISPR)相关。我们的目标是 改善这些RNA的细胞摄取、递送和序列特异性。前提是阿米德 可以模拟磷酸盐与蛋白质的结构和氢键相互作用，在某些位置，可以 能够重塑和改善这些互动。项目2探索化学修饰的PNA作为配体 用于对生物医学上重要的dsRNA进行序列特异性识别。我们的目标是改善蜂窝 PNA的摄取和以microRNAs为初始的三链形成的生物学效应 模型系统。前提是M-修饰的三链形成的PNA唯一适合于序列- 特异性识别dsRNA，并将使识别具有生物重要性的非编码dsRNA成为可能。 未来的研究将集中在CRISPR RNA的化学修饰和使用三螺旋来控制 复杂的非编码RNA的构象。这些项目涉及与结构生物化学家的合作。 (Martin Egli)、生物化学家(Naoki Sugimoto)和一家制药公司(Alnylam)。两个人 项目有一个共同的主题，那就是设计利用电荷的化学修饰 RNA靶标与与RNA相互作用的配体和蛋白质之间的互补性。这个 过分的想法是开发RNA化学修饰和RNA结合配体，以避免 非生产性静电排斥和利用生产性静电吸引的同时 增强分子相互作用的序列特异性。这一推力源于我们最近的发现 这种核糖核酸不同寻常地容易接受中和磷酸盐负电荷的化学修饰。 骨架，在RNA本身和RNA结合的寡核苷酸类似物中都是如此。如果成功，我们的研究将 有助于解决RNA干扰、CRISPR、治疗相关性识别方面的关键差距 RNAs，并将为开发独特的研究工具和新的治疗策略打开大门。

Recent decades have dramatically changed our view of RNA. While RNA was initially believed to be barely a passive messenger in the transfer of genetic information from DNA to proteins, it is now clear that RNA is an exciting and underexplored regulatory molecule that will continue to deliver new discoveries in biology and medicine. Our research program strives to capitalize on these exciting future discoveries by using chemical modifications to modulate the structure and function regulatory RNAs. The long-term goals are to 1) develop novel RNA chemical modifications for fundamental studies and biomedical applications, and 2) explore new modes of sequence-specific recognition of double-stranded RNA (dsRNA). Our research program comprises two distinct but interrelated projects: 1) amides as novel backbone modifications for regulatory RNAs, and 2) sequence-specific recognition of dsRNA by modified peptide nucleic acids (PNA). Project 1 replaces internucleotide phosphates with amide linkages in short interfering RNAs and RNAs associated with clustered regularly interspaced short palindromic repeats (CRISPR). The goals are to improve the cellular uptake, delivery and sequence specificity of these RNAs. The premise is that amides can mimic structure and H-bonding interactions of phosphates with proteins and, at certain positions, may be able to remodel and improve these interactions. Project 2 explores chemically modified PNA as a ligand for sequence-specific recognition of biomedically important dsRNA. The goals are to improve the cellular uptake of PNA and to demonstrate the biological effect of triplex formation using microRNAs as the initial model system. The premise is that M-modified triplex-forming PNAs are uniquely suited for sequence- specific recognition of dsRNA and will enable recognition of biologically important non-coding dsRNA. Future research will focus on chemical modifications of CRISPR RNAs and using the triple helix to control conformations of complex non-coding RNAs. The projects involve collaborations with structural biochemists (Martin Egli), biological chemists (Naoki Sugimoto), and a pharmaceutical company (Alnylam). The two projects share a common theme of designing chemical modifications that take advantage of charge complementarity between the RNA target and the ligands and proteins interacting with RNA. The overreaching idea is to develop RNA chemical modifications and RNA binding ligands that avoid unproductive electrostatic repulsion and capitalize on productive electrostatic attraction while concurrently enhancing sequence specificity of molecular interactions. This thrust grows out of our recent discoveries that RNA is unusually receptive to chemical modifications that neutralize the negative charge of phosphate backbone, both in RNA itself and in RNA binding oligonucleotide analogues. If successful, our research will contribute to addressing key gaps in RNA interference, CRISPR, recognition of therapeutically relevant RNAs, and will open doors for development of unique research tools and new therapeutic strategies.