Rad5 dysregulation drives hyperactive recombination at replication forks resulting in cisplatin sensitivity and...

Area of Science:

• Molecular Biology
• Genetics
• Cancer Research

Background:

• The postreplication repair gene HLTF is amplified and overexpressed in cancer.
• HLTF plays a crucial role in DNA repair and genome stability.

Purpose of the Study:

• To model HLTF dysregulation using its conserved yeast ortholog, RAD5.
• To investigate the genetic requirements and molecular mechanisms underlying RAD5 overexpression (RAD5OE).

Main Methods:

• Genetic interaction profiling and landscape enrichment analysis in Saccharomyces cerevisiae.
• Analysis of DNA replication intermediates and recombination assays.
• Investigating the role of specific protein domains and post-translational modifications.

Main Results:

• RAD5OE requires genes involved in recombination, crossover resolution, and DNA replication.
• RAD5OE causes cisplatin sensitivity and drives recombination in repetitive DNA regions.
• The RAD5OE phenotype depends on a DNA-binding domain and affects replication forks, independent of other postreplication repair pathways.

Conclusions:

• Dysregulated RAD5 leads to aberrant template switching at replication forks, increased recombination, and sensitivity to DNA damaging agents.
• These findings predict similar consequences for dysregulated HLTF in cancer.
• HLTF's role in cancer may involve direct effects on replication fork dynamics and genome instability.