A systems approach to mapping DNA damage response pathways.

Area of Science:

• Molecular Biology
• Genetics
• Systems Biology

Background:

• Cellular response to DNA damage is crucial for preventing mutagenesis and mitigating environmental toxicity.
• Understanding the transcriptional network governing DNA damage response is essential for comprehending cellular defense mechanisms.

Purpose of the Study:

• To map the genomewide transcriptional network controlling the DNA damage response in yeast.
• To identify transcription factor (TF)-target interactions and binding motifs involved in response to methyl-methanesulfonate (MMS).
• To construct causal pathway models integrating signaling, transcription, and phenotype after DNA damage.

Main Methods:

• Genomewide binding locations of 30 damage-related transcription factors (TFs) were measured in yeast exposed to methyl-methanesulfonate (MMS).
• TF-target interactions were identified, and functional validation was performed by assessing target gene expression changes in wild-type versus TF-deficient yeast.
• Validated interactions were used to build causal pathway models.

Main Results:

• A total of 5272 TF-target interactions were identified, showing extensive changes in promoter binding patterns upon MMS exposure.
• Damage-specific binding motifs were discovered, providing insights into the regulatory mechanisms of DNA damage response.
• Functional validation confirmed numerous TF-target interactions critical for the transcriptional response to MMS.

Conclusions:

• The study reveals a complex transcriptional network governing the DNA damage response in yeast.
• The identified TF-target interactions and pathways offer a global view of how cells integrate signaling, transcription, and phenotypic outcomes following DNA damage.
• This provides a foundation for understanding mutagenesis and environmental toxicity at a molecular level.