Schizosaccharomyces pombe Hsk1p Is a Potential Cds1p Target Required for Genome Integrity
AUTOR(ES)
Snaith, Hilary A.
FONTE
American Society for Microbiology
RESUMO
The fission yeast Hsk1p kinase is an essential activator of DNA replication. Here we report the isolation and characterization of a novel mutant allele of the gene. Consistent with its role in the initiation of DNA synthesis, hsk1ts genetically interacts with several S-phase mutants. At the restrictive temperature, hsk1ts cells suffer abnormal S phase and loss of nuclear integrity and are sensitive to both DNA-damaging agents and replication arrest. Interestingly, hsk1ts mutants released to the restrictive temperature after early S-phase arrest in hydroxyurea (HU) are able to complete bulk DNA synthesis but they nevertheless undergo an abnormal mitosis. These findings indicate a second role for hsk1 subsequent to HU arrest. Consistent with a later S-phase role, hsk1ts is synthetically lethal with Δrqh1 (RecQ helicase) or rad21ts (cohesin) mutants and suppressed by Δcds1 (RAD53 kinase) mutants. We demonstrate that Hsk1p undergoes Cds1p-dependent phosphorylation in response to HU and that it is a direct substrate of purified Cds1p kinase in vitro. These results indicate that the Hsk1p kinase is a potential target of Cds1p regulation and that its activity is required after replication initiation for normal mitosis.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=86403Documentos Relacionados
- hsk1+, a Schizosaccharomyces pombe gene related to Saccharomyces cerevisiae CDC7, is required for chromosomal replication.
- Schizosaccharomyces pombe Pmr1p Is Essential for Cell Wall Integrity and Is Required for Polarized Cell Growth and Cytokinesis
- Schizosaccharomyces pombe Git7p, a Member of the Saccharomyces cerevisiae Sgt1p Family, Is Required for Glucose and Cyclic AMP Signaling, Cell Wall Integrity, and Septation
- Phosphorylation at Thr167 is required for Schizosaccharomyces pombe p34cdc2 function.
- Bgs3p, a Putative 1,3-β-Glucan Synthase Subunit, Is Required for Cell Wall Assembly in Schizosaccharomyces pombe