A Rad3-Rad26 complex responds to DNA damage independently of other checkpoint proteins.
The conserved PIK-related kinase Rad3 is required for all DNA-integrity-checkpoint responses in fission yeast. Here we report a stable association between Rad3 and Rad26 in soluble protein extracts. Rad26 shows Rad3-dependent phosphorylation after DNA damage. Unlike phosphorylation of Hus1, Crb2/Rhp9, Cds1 and Chk1, phosphorylation of Rad26 does not require other known checkpoint proteins. Rad26 phosphorylation is the first biochemical marker of Rad3 function, indicating that Rad3-related checkpoint kinases may have a direct role in DNA-damage recognition.
Edwards
R J
RJ
MRC Cell Mutation Unit, Sussex University, Falmer BN1 9RR, UK.
Bentley
N J
NJ
Carr
A M
AM
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000502:physiology*; D004249:DNA Damage; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005720:Gamma Rays; D006918:Hydroxyurea / Q000494:pharmacology; D046911:Macromolecular Substances; D008954:Models, Biological; D010766:Phosphorylation; D029701:Saccharomyces cerevisiae Proteins; D012568:Schizosaccharomyces / Q000166:cytology* / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D029702:Schizosaccharomyces pombe Proteins; D014466:Ultraviolet Rays
D018797:Cell Cycle Proteins; D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D046911:Macromolecular Substances; D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; C088086:rad26 protein, S pombe; D000251:Adenosine Triphosphatases; C061897:Rad3 protein, S cerevisiae; D004265:DNA Helicases; D006918:Hydroxyurea