Potent modulators of RNA function can be assembled in cellulo by using the cell as a reaction vessel and a disease-causing RNA as a catalyst. When designing small molecule effectors of function, a balance between permeability and potency must be struck. Low molecular weight compounds are more permeable while higher molecular weight compounds are more potent. The advantages of both types of compounds could be synergized if low molecular weight molecules could be transformed into potent, multivalent ligands via a reaction catalyzed by binding to a target in cells expressing a genetic defect. We demonstrate that this approach is indeed viable in cellulo. Small molecule modules with precisely positioned alkyne and azide moieties bind adjacent internal loops in r(CCUG)exp, the causative agent of myotonic dystrophy type 2 (DM2), and are transformed into oligomeric, potent inhibitors of DM2 RNA dysfunction via a 1,3 Huisgen dipolar cycloaddition reaction, a variant of click chemistry. Additionally, we show that this approach is applicable to the r(CUG) repeating RNA that causes myotonic dystrophy type 1 (DM1). The click chemistry approach also allows for FRET sensors to be synthesized on-site by using r(CUG) repeats as a catalyst. Furthermore it is shown that small molecule binding sites in patient-derived cells can be identified by using reactive approaches termed Chem-CLIP and Chem-CLIP-Map. Lastly, it is shown that small molecules that target r(CUG) expansions can be designed to cleave this RNA by appending a small molecule with a nucleic acid cleaving module.
RNA功能的有效调节剂可以在细胞内组装,通过将细胞作为反应容器,以疾病引起的RNA作为催化剂。在设计小分子功能调节剂时,必须在渗透性和效力之间取得平衡。低分子量化合物更易渗透,而高分子量化合物更有效。如果可以通过在表达
基因缺陷的细胞中与靶标结合催化的反应将低分子量分子转化为有效的、多价
配体,那么这两种化合物的优势就可以协同作用。我们证明这种方法在细胞内确实是可行的。具有精确定位炔基和
叠氮基团的小分子模块与(rCCUG)exp中相邻的内部环结合,这是肌无力型肌萎缩症2型(
DM2)的致病因子,并通过1,3 Huisgen偶极环加成反应,点击
化学的一种变体,转化为多聚体、有效的
DM2 RNA功能
抑制剂。此外,我们还展示了这种方法适用于导致肌无力型肌萎缩症1型(
DM1)的r(CUG)重复RNA。点击
化学方法还允许通过使用r(CUG)重复作为催化剂在现场合成FRET传感器。此外,通过使用称为Chem-CLIP和Chem-CLIP-Map的反应性方法,还可以识别患者来源细胞中的小分子结合位点。最后,还展示了可以设计针对r(CUG)扩增的小分子,通过附加具有核酸切割模块的小分子来切割这种RNA。