Splicing factor SRSF1 negatively regulates alternative splicing of MDM2 under damage. Nucleic Acids Res 2015 Apr 30;43(8):4202-18
Date
04/08/2015Pubmed ID
25845590Pubmed Central ID
PMC4417157DOI
10.1093/nar/gkv223Scopus ID
2-s2.0-84930221684 (requires institutional sign-in at Scopus site) 32 CitationsAbstract
Genotoxic stress induces alternative splicing of the oncogene MDM2 generating MDM2-ALT1, an isoform attributed with tumorigenic properties. However, the mechanisms underlying this event remain unclear. Here we explore MDM2 splicing regulation by utilizing a novel minigene that mimics endogenous MDM2 splicing in response to UV and cisplatinum-induced DNA damage. We report that exon 11 is necessary and sufficient for the damage-specific alternative splicing of the MDM2 minigene and that the splicing factor SRSF1 binds exon 11 at evolutionarily conserved sites. Interestingly, mutations disrupting this interaction proved sufficient to abolish the stress-induced alternative splicing of the MDM2 minigene. Furthermore, SRSF1 overexpression promoted exclusion of exon 11, while its siRNA-mediated knockdown prevented the stress-induced alternative splicing of endogenous MDM2. Additionally, we observed elevated SRSF1 levels under stress and in tumors correlating with the expression of MDM2-ALT1. Notably, we demonstrate that MDM2-ALT1 splicing can be blocked by targeting SRSF1 sites on exon 11 using antisense oligonucleotides. These results present conclusive evidence supporting a negative role for SRSF1 in MDM2 alternative splicing. Importantly, we define for the first time, a clear-cut mechanism for the regulation of damage-induced MDM2 splicing and present potential strategies for manipulating MDM2 expression via splicing modulation.
Author List
Comiskey DF Jr, Jacob AG, Singh RK, Tapia-Santos AS, Chandler DSMESH terms used to index this publication - Major topics in bold
Alternative SplicingDNA Damage
Exons
HeLa Cells
Humans
MCF-7 Cells
Nuclear Proteins
Oligodeoxyribonucleotides, Antisense
Proto-Oncogene Proteins c-mdm2
RNA-Binding Proteins
Regulatory Sequences, Ribonucleic Acid
Rhabdomyosarcoma
Serine-Arginine Splicing Factors
Stress, Physiological
