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Abrahams L, Savisaar R, Mordstein C, Young B, Kudla G, Hurst LD. Evidence in disease and non-disease contexts that nonsense mutations cause altered splicing via motif disruption. Nucleic Acids Res 2021; 49:9665-9685. [PMID: 34469537 PMCID: PMC8464065 DOI: 10.1093/nar/gkab750] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 08/17/2021] [Accepted: 08/19/2021] [Indexed: 12/21/2022] Open
Abstract
Transcripts containing premature termination codons (PTCs) can be subject to nonsense-associated alternative splicing (NAS). Two models have been evoked to explain this, scanning and splice motif disruption. The latter postulates that exonic cis motifs, such as exonic splice enhancers (ESEs), are disrupted by nonsense mutations. We employ genome-wide transcriptomic and k-mer enrichment methods to scrutinize this model. First, we show that ESEs are prone to disruptive nonsense mutations owing to their purine richness and paucity of TGA, TAA and TAG. The motif model correctly predicts that NAS rates should be low (we estimate 5–30%) and approximately in line with estimates for the rate at which random point mutations disrupt splicing (8–20%). Further, we find that, as expected, NAS-associated PTCs are predictable from nucleotide-based machine learning approaches to predict splice disruption and, at least for pathogenic variants, are enriched in ESEs. Finally, we find that both in and out of frame mutations to TAA, TGA or TAG are associated with exon skipping. While a higher relative frequency of such skip-inducing mutations in-frame than out of frame lends some credence to the scanning model, these results reinforce the importance of considering splice motif modulation to understand the etiology of PTC-associated disease.
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Affiliation(s)
- Liam Abrahams
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK
| | - Rosina Savisaar
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK.,Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Christine Mordstein
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK.,MRC Human Genetics Unit, The University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK.,Aarhus University, Department of Molecular Biology and Genetics, C F Møllers Allé 3, 8000 Aarhus, Denmark
| | - Bethan Young
- MRC Human Genetics Unit, The University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Grzegorz Kudla
- MRC Human Genetics Unit, The University of Edinburgh, Crewe Road, Edinburgh EH4 2XU, UK
| | - Laurence D Hurst
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK
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