title: The cardiotonic steroid digitoxin regulates alternative splicing through depletion of the splicing factors SRSF3 and TRA2B.
abstract: Modulation of alternative pre-mRNA splicing is a potential approach to therapeutic targeting for a variety of human diseases. We investigated the mechanism by which digitoxin, a member of the cardiotonic steroid class of drugs, regulates alternative splicing. Transcriptome-wide analysis identified a large set of alternative splicing events that change after digitoxin treatment. Within and adjacent to these regulated exons, we identified enrichment of potential binding sites for the splicing factors SRp20 (SRSF3/SFRS3) and Tra2-β (SFRS10/TRA2B). We further find that both of these proteins are depleted from cells by digitoxin treatment. Characterization of SRp20 and Tra2-β splicing targets revealed that many, but not all, digitoxin-induced splicing changes can be attributed to the depletion of one or both of these factors. Re-expression of SRp20 or Tra2-β after digitoxin treatment restores normal splicing of their targets, indicating that the digitoxin effect is directly due to these factors. These results demonstrate that cardiotonic steroids, long prescribed in the clinical treatment of heart failure, have broad effects on the cellular transcriptome through these and likely other RNA binding proteins. The approach described here can be used to identify targets of other potential therapeutics that act as alternative splicing modulators.
authors.affiliation: Molecular Biology Interdepartmental Graduate Program, University of California, Los Angeles, California 90095, USA.
authors.forename: Erik S
authors.initials: ES
authors.lastname: Anderson
authors.forename: Chia-Ho
authors.initials: CH
authors.lastname: Lin
authors.forename: Xinshu
authors.initials: X
authors.lastname: Xiao
authors.forename: Peter
authors.initials: P
authors.lastname: Stoilov
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Burge
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Black
mesh_terms: D017398:Alternative Splicing / Q000187:drug effects*; D001665:Binding Sites; D002316:Cardiotonic Agents / Q000494:pharmacology*; D002460:Cell Line; D004074:Digitoxin / Q000494:pharmacology*; D005091:Exons; D015870:Gene Expression; D006801:Humans; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D055550:Protein Stability / Q000187:drug effects; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000068103:Serine-Arginine Splicing Factors
chemical_list: D002316:Cardiotonic Agents; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; C491388:SRSF3 protein, human; C097083:TRA2B protein, human; D000068103:Serine-Arginine Splicing Factors; D004074:Digitoxin