Cotranscriptional exon skipping in the genotoxic stress response

Area of Science:

• Molecular Biology
• Cellular Stress Response
• Gene Regulation

Background:

• Pre-messenger RNA (pre-mRNA) splicing is intrinsically linked to transcription.
• Genotoxic stresses can influence alternative splicing by affecting RNA polymerase II elongation.
• Ewing's sarcoma proto-oncoprotein (EWS) and YB-1 are key factors in RNA processing.

Purpose of the Study:

• To investigate how genotoxic stress affects the interaction between EWS and YB-1.
• To determine the impact of this interaction on pre-mRNA splicing, specifically exon skipping.
• To elucidate the role of stress-induced splicing alterations in the p53 pathway and cellular response.

Main Methods:

• Utilized genotoxic stress inducers like camptothecin (CPT).
• Assessed the interaction between EWS and YB-1 under stress conditions.
• Employed splicing-sensitive microarrays to identify differentially spliced exons.
• Analyzed MDM2 gene expression and p53 accumulation.

Main Results:

• Genotoxic stress, including CPT treatment, inhibits EWS-YB-1 interaction.
• This inhibition leads to cotranscriptional skipping of specific exons in the MDM2 gene.
• The observed exon skipping is reversible and regulates MDM2 expression.
• Splicing-sensitive microarrays revealed widespread exon skipping in response to CPT and EWS-YB-1 depletion.

Conclusions:

• Genotoxic stress alters communication between transcriptional and splicing machineries.
• Widespread exon skipping is a significant consequence of this altered communication.
• Stress-induced splicing changes play a crucial role in the cellular genotoxic stress response, affecting p53 regulation.