ABSTRACT
Splicing modifiers promoting SMN2 exon 7 inclusion have the potential to treat spinal muscular atrophy, the leading genetic cause of infantile death. These small molecules are SMN2 exon 7 selective and act during the early stages of spliceosome assembly. Here, we show at atomic resolution how the drug selectively promotes the recognition of the weak 5' splice site of SMN2 exon 7 by U1 snRNP. The solution structure of the RNA duplex formed following 5' splice site recognition in the presence of the splicing modifier revealed that the drug specifically stabilizes a bulged adenine at this exon-intron junction and converts the weak 5' splice site of SMN2 exon 7 into a stronger one. The small molecule acts as a specific splicing enhancer cooperatively with the splicing regulatory network. Our investigations uncovered a novel concept for gene-specific alternative splicing correction that we coined 5' splice site bulge repair.
Subject(s)
RNA Splicing , RNA/chemistry , Molecular Conformation , Muscular Atrophy, Spinal/metabolism , Ribonucleoprotein, U1 Small Nuclear/chemistryABSTRACT
Protein-RNA complex formation is at the center of RNA metabolism and leads to the modulation of protein and RNA functions. We propose here a step-by-step guide to investigate these interactions including the identification of the protein and RNA parts involved in complex formation, the determination of the affinity of the complex and the characterization of the protein-RNA interface at amino acid and nucleotide level. Moreover, we briefly review the methods that are the most often used to obtain this information using primarily examples from our lab and finally mention what we perceive as the next challenges in the field.
