Sisomicin binds and stabilizes the folded structure of CUG RNA repeats, demonstrated by a novel fluorescence-based binding assay consistent with classic UV Tm techniques.
A novel fluorescence-based assay successfully characterizes the binding of sisomicin to CUG RNA repeats, offering a high-throughput screening method for potential therapeutics in myotonic dystrophy.
Pathogenic CUG and CCUG RNA repeats have been associated with myotonic dystrophy type 1 and 2 (DM1 and DM2), respectively. Identifying small molecules that can bind these RNA repeats is of great significance to develop potential therapeutics to treat these neurodegenerative diseases. Some studies have shown that aminoglycosides and their derivatives could work as potential lead compounds targeting these RNA repeats. In this work, sisomicin, previously known to bind HIV-1 TAR, is investigated as a possible ligand for CUG RNA repeats. We designed a novel fluorescence-labeled RNA sequence of r(CUG)10 to mimic cellular RNA repeats and improve the detecting sensitivity. The interaction of sisomicin with CUG RNA repeats is characterized by the change of fluorescent signal, which is initially minimized by covalently incorporating the fluorescein into the RNA bases and later increased upon ligand binding. The results show that sisomicin can bind and stabilize the folded RNA structure. We demonstrate that this new fluorescence-based binding characterization assay is consistent with the classic UV Tm technique, indicating its feasibility for high-throughput screening of ligand-RNA binding interactions and wide applications to measure the thermodynamic parameters in addition to binding constants and kinetics when probing such interactions.
Chang et al. (Sat,) conducted a other in Myotonic dystrophy type 1 and 2. Sisomicin was evaluated on Binding and stabilization of folded RNA structure. Sisomicin binds and stabilizes the folded structure of CUG RNA repeats, demonstrated by a novel fluorescence-based binding assay consistent with classic UV Tm techniques.