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Schizosaccharomyces pombe checkpoint response to DNA interstrand cross-links
- Publication Year :
- 2016
-
Abstract
- Drugs that produce covalent interstrand cross-links (ICLs) in DNA remain central to the treatment of cancer, but the cell cycle checkpoints activated by ICLs have received little attention. We have used the fission yeast, Schizosaccharomyces pombe, to elucidate the checkpoint responses to the ICL-inducing anticancer drugs nitrogen mustard and mitomycin C. First we confirmed that the repair pathways acting on ICLs in this yeast are similar to those in the main organisms studied to date (Escherichia coli, budding yeast, and mammalian cells), principally nucleotide excision repair and homologous recombination. We also identified and disrupted the S. pombe homologue of the Saccharomyces cerevisiae SNM1/PSO2 ICL repair gene and found that this activity is required for normal resistance to cross-linking agents, but not other forms of DNA damage. Survival and biochemical analysis indicated a key role for the "checkpoint Rad" family acting through the chk1-dependent DNA damage checkpoint in the ICL response. Rhp9-dependent phosphorylation of Chk1 correlates with G(2) arrest following ICL induction. In cells able to bypass the G(2) block, a second-cycle (S-phase) arrest was observed. Only a transient activation of the Cds1 DNA replication checkpoint factor occurs following ICL formation in wild-type cells, but this is increased and persists in G(2) arrest-deficient mutants. This likely reflects the fraction of cells escaping the G(2) damage checkpoint and arresting in the subsequent S phase due to ICL replication blocks. Disruption of cds1 confers increased resistance to ICLs, suggesting that this second-cycle S-phase arrest might be a lethal event.
- Subjects :
- G2 Phase
Radiation-Sensitizing Agents
Cell cycle checkpoint
Time Factors
DNA Repair
DNA repair
Cell Survival
Mitomycin
Biology
Protein Serine-Threonine Kinases
S Phase
Schizosaccharomyces
Hydroxyurea
CHEK1
Enzyme Inhibitors
Phosphorylation
Molecular Biology
Nucleic Acid Synthesis Inhibitors
Recombination, Genetic
Dose-Response Relationship, Drug
Temperature
Dose-Response Relationship, Radiation
Cell Biology
DNA
G2-M DNA damage checkpoint
biology.organism_classification
Molecular biology
DNA Dynamics and Chromosome Structure
DNA replication checkpoint
Checkpoint Kinase 2
Cross-Linking Reagents
Schizosaccharomyces pombe
Camptothecin
Schizosaccharomyces pombe Proteins
Cisplatin
Protein Kinases
Nucleotide excision repair
DNA Damage
Subjects
Details
- Language :
- English
- ISSN :
- 10985549
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....1278b4f5e37adb440084da9c034dbc7e