Replication fork stalling caused by deoxynucleotide depletion triggers Rad53 phosphorylation and subsequent checkpoint activation, which in turn plays a crucial role in maintaining functional DNA replication forks. How cells regulate checkpoint deactivation after inhibition of DNA replication is poorly understood. Here, we show that the budding yeast protein phosphatase Glc7/PP1 promotes disappearance of phosphorylated Rad53 and recovery from replication fork stalling caused by the dNTP synthesis inhibitor hydroxyurea (HU). Glc7 is also required for recovery from a DSB-induced checkpoint, while it is dispensable for checkpoint inactivation during MMS exposure, which instead requires the protein phosphatases Pph3, Ptc2 and Ptc3. Furthermore, Glc7 counteracts in vivo histone H2A phosphorylation on serine 129 (gammaH2A) and dephosphorylates gammaH2A in vitro. Finally, the replication recovery defects of HU-treated glc7 mutants are partially rescued by Rad53 inactivation or lack of gammaH2A formation, and the latter also counteracts hyperphosphorylated Rad53 accumulation. We therefore propose that Glc7 activity promotes recovery from replication fork stalling caused by dNTP depletion, and that gammaH2A dephosphorylation is a critical Glc7 function in this process.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Annotation Extension||Reference|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Assay||Construct||Conditions||Strain Background||Reference|