Cotranscriptional exon skipping in the genotoxic stress response

Abstract

Pre-mRNA splicing is functionally coupled to transcription, and genotoxic stresses can enhance alternative exon inclusion by affecting elongating RNA polymerase II. We report here that various genotoxic stress inducers, including camptothecin (CPT), inhibit the interaction between Ewing's sarcoma proto-oncoprotein (EWS), an RNA polymerase II-associated factor, and YB-1, a spliceosome-associated factor. This results in the cotranscriptional skipping of several exons of the MDM2 gene, which encodes the main p53 ubiquitin ligase. This reversible exon skipping participates in the regulation of MDM2 expression that may contribute to the accumulation of p53 during stress exposure and its rapid shut-off when stress is removed. Finally, a splicing-sensitive microarray identified numerous exons that are skipped in response to CPT and EWS-YB-1 depletion. These data demonstrate genotoxic stress-induced alteration of the communication between the transcriptional and splicing machineries, which results in widespread exon skipping and plays a central role in the genotoxic stress response.

Four parameters increase the sensitivity and specificity of the exon array analysis and disclose 25 novel aberrantly spliced exons in myotonic dystrophy

“…To prove this, we analyzed four human exon arrays of GSE21795, 23 GSE28672, 24 GSE24581 25 and GSE21840 26 in the Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo/). Each data set was comprised of a pair of three to five samples, and aberrant and alternative splicing events of a total of 23 exons were validated by RT-PCR in the original papers.…”

GDNF Signaling Regulates YBX1/mRNA Interactions in Mouse Spermatogonia.

“…YBX1 also has splicing related defects that are synergistically decreased when co-depleted along with EWSR1 [11]. This suggests that YBX1 works with other SSC-associated RNA binding proteins to regulate RNA in a variety of ways in the male germline.…”

“…It is widely expressed across a broad range of tissues, but in vivo data on the biological function of YBX1 is limited because the Ybx1 null mouse is embryonic lethal [192,193]. YBX1 is as broad in its cellular function as in its expression, involved in transcription, translational control and splicing depending on the cell type expressing it and post-translational modifications [11,24,36,39,41,42,[48][49][50][51][193][194][195][196]. Perhaps because of its myriad cellular roles, there is little consistency about when developmentally it is expressed across tissues, or where inside the cell it is located, with it being reported in the nucleus, cytoplasm, or shuttling between the two based on posttranscriptional modifications [41,188,194,[196][197][198].…”

“…YBX1 has a broad range of reported functions including transcriptional regulation and splicing depending on the cell type expressing it and post-translational modifications [11,49,51,[193][194][195][196][197][198][199]212]. The other major function of YBX1 is in RNA translational control, generally through mRNA sequestration and prevention of transcript degradation, although some studies suggest that it can positively regulate translation as well [24, 36, 39-42, 45-48, 50, 52, 53].…”

Régulation cinétique de l’épissage alternatif des pré-ARN messagers : attention au ralentissement

“…Par ailleurs, des molécules connues pour inhiber globalement l'élongation de la transcription, comme le DRB ou la camptothécine, ont été utilisées pour réaliser des études à haut débit de l'épissage alternatif [11]. Il a ainsi été montré qu'une majorité des exons alternatifs répondaient au modèle ciné-tique, mais également qu'une partie non négligeable d'exons se comportaient de manière opposée, l'usage de ces molécules induisant une augmentation de leur exclusion.…”