Specific transcripts are elevated in Saccharomyces cerevisiae in response to DNA damage

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• DNA damage response pathways are crucial for maintaining genomic integrity in eukaryotic cells.
• Understanding gene regulation under DNA-damaging conditions is essential for comprehending cellular repair mechanisms.

Purpose of the Study:

• To identify and characterize genes in Saccharomyces cerevisiae that are upregulated in response to DNA damage.
• To investigate the transcriptional regulation of these damage-inducible genes.

Main Methods:

• Differential hybridization was employed to screen approximately 9,000 yeast genomic clones.
• Southern hybridization analysis was used to characterize repetitive elements and transcript sizes.
• Kinetic analysis and Northern hybridization were performed to quantify transcript levels.

Main Results:

• Four DNA damage-responsive genes were isolated and characterized.
• Two genes (lambda 78A and pBR178C) contained repetitive elements and hybridized to 5-kilobase transcripts.
• Two other genes (pBRA2 and pBR3016B) were single-copy and hybridized to 0.5- and 3.2-kilobase transcripts, respectively.
• The transcript for pBRA2 showed a >15-fold increase within 20 minutes after 4-nitroquinoline-1-oxide (NQO) exposure and was elevated in rad52-1 mutant cells.

Conclusions:

• Specific genes in eukaryotic cells are transcriptionally activated by DNA damage.
• The rad52-1 mutation, involved in DNA repair, affects the induction of specific damage-responsive transcripts.
• This study provides foundational evidence for DNA damage-induced gene transcription in eukaryotes.