A Targeted Oligonucleotide Enhancer of SMN2 Exon 7 Splicing Forms Competing Quadruplex and Protein Complexes in Functional Conditions

Abstract

The use of oligonucleotides to activate the splicing of selected exons is limited by a poor understanding of the mechanisms affected. A targeted bifunctional oligonucleotide enhancer of splicing (TOES) anneals to SMN2 exon 7 and carries an exonic splicing enhancer (ESE) sequence. We show that it stimulates splicing specifically of intron 6 in the presence of repressing sequences in intron 7. Complementarity to the 5? end of exon 7 increases U2AF65 binding, but the ESE sequence is required for efficient recruitment of U2 snRNP. The ESE forms at least three coexisting discrete states: a quadruplex, a complex containing only hnRNP F/H, and a complex enriched in the activator SRSF1. Neither hnRNP H nor quadruplex formation contributes to ESE activity. The results suggest that splicing limited by weak signals can be rescued by rapid exchange of TOES oligonucleotides in various complexes and raise the possibility that SR proteins associate transiently with ESEs.

Citation

Smith, L., Dickinson, R., Lucas, C., Cousins, A., Malygin, A., Weldon, C., …Eperon, I. (2014). A Targeted Oligonucleotide Enhancer of SMN2 Exon 7 Splicing Forms Competing Quadruplex and Protein Complexes in Functional Conditions. Cell Reports, 9(1), 193-205. https://doi.org/10.1016/j.celrep.2014.08.051

• Journal Article Type: Article
• Acceptance Date: Aug 21, 2014
• Online Publication Date: Sep 25, 2014
• Publication Date: Oct 9, 2014
• Deposit Date: Dec 4, 2018
• Publicly Available Date: Apr 11, 2019
• Journal: Cell Reports
• Print ISSN: 2211-1247
• Publisher: Elsevier (Cell Press)
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 1
• Pages: 193-205
• DOI: https://doi.org/10.1016/j.celrep.2014.08.051
• Keywords: General Biochemistry, Genetics and Molecular Biology
• Public URL: https://nottingham-repository.worktribe.com/output/1362833
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S221112471400727X
• Additional Information: This article is maintained by: Elsevier; Article Title: A Targeted Oligonucleotide Enhancer of SMN2 Exon 7 Splicing Forms Competing Quadruplex and Protein Complexes in Functional Conditions; Journal Title: Cell Reports; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.celrep.2014.08.051; Content Type: article; Copyright: Copyright © 2014 The Authors. Published by Elsevier Inc.