1. Spinal muscular atrophy: SMN2 pre-mRNA splicing corrected by a U7 snRNA derivative carrying a splicing enhancer sequence.
- Author
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Marquis J, Meyer K, Angehrn L, Kämpfer SS, Rothen-Rutishauser B, and Schümperli D
- Subjects
- Base Sequence, Cell Line, Cyclic AMP Response Element-Binding Protein genetics, DNA, Antisense genetics, Exons genetics, Fibroblasts, Humans, Molecular Sequence Data, Muscular Atrophy, Spinal pathology, Nerve Tissue Proteins genetics, RNA, Messenger genetics, RNA-Binding Proteins genetics, SMN Complex Proteins, Survival of Motor Neuron 1 Protein, Survival of Motor Neuron 2 Protein, Time Factors, Cyclic AMP Response Element-Binding Protein metabolism, Muscular Atrophy, Spinal genetics, Muscular Atrophy, Spinal metabolism, Nerve Tissue Proteins metabolism, RNA Splicing genetics, RNA, Small Nuclear genetics, RNA-Binding Proteins metabolism
- Abstract
Spinal muscular atrophy (SMA) is a lethal hereditary disease caused by homozygous deletion/inactivation of the survival of motoneuron 1 (SMN1) gene. The nearby SMN2 gene, despite its identical coding capacity, is only an incomplete substitute, because a single nucleotide difference impairs the inclusion of its seventh exon in the messenger RNA (mRNA). This splicing defect can be corrected (transiently) by specially designed oligonucleotides. Here we have developed a more permanent correction strategy based on bifunctional U7 small nuclear RNAs (snRNAs). These carry both an antisense sequence that allows specific binding to exon 7 and a splicing enhancer sequence that will improve the recognition of the targeted exon. When expression cassettes for these RNAs are stably introduced into cells, the U7 snRNAs become incorporated into small nuclear ribonucleoprotein (snRNP) particles that will induce a durable splicing correction. We have optimized this strategy to the point that virtually all SMN2 pre-mRNA becomes correctly spliced. In fibroblasts from an SMA patient, this approach induces a prolonged restoration of SMN protein and ensures its correct localization to discrete nuclear foci (gems).
- Published
- 2007
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