RRC ID 12527
Author Díaz-Cuervo H, Bueno A.
Title Cds1 controls the release of Cdc14-like phosphatase Flp1 from the nucleolus to drive full activation of the checkpoint response to replication stress in fission yeast.
Journal Mol. Biol. Cell
Abstract The Cdc14p-like phosphatase Flp1p (also known as Clp1p) is regulated by cell cycle-dependent changes in its subcellular localization. Flp1p is restricted to the nucleolus and spindle pole body until prophase, when it is dispersed throughout the nucleus, mitotic spindle, and medial ring. Once released, Flp1p antagonizes Cdc2p/cyclin activity by reverting Cdc2p-phosphorylation sites on Cdc25p. On replication stress, ataxia-telangiectasia mutated/ATM/Rad3-related kinase Rad3p activates Cds1p, which phosphorylates key proteins ensuring the stability of stalled DNA replication forks. Here, we show that replication stress induces changes in the subcellular localization of Flp1p in a checkpoint-dependent manner. Active Cds1p checkpoint kinase is required to release Flp1p into the nucleus. Consistently, a Flp1p mutant (flp1-9A) lacking all potential Cds1p phosphorylation sites fails to relocate in response to replication blocks and, similarly to cells lacking flp1 (Deltaflp1), presents defects in checkpoint response to replication stress. Deltaflp1 cells accumulate reduced levels of a less active Cds1p kinase in hydroxyurea (HU), indicating that nuclear Flp1p regulates Cds1p full activation. Consistently, Deltaflp1 and flp1-9A have an increased percentage of Rad22p-recombination foci during HU treatment. Together, our data show that by releasing Flp1p into the nucleus Cds1p checkpoint kinase modulates its own full activation during replication stress.
Volume 19(6)
Pages 2488-99
Published 2008-6
DOI 10.1091/mbc.e07-08-0737
PII E07-08-0737
PMID 18385517
PMC PMC2397296
MeSH 14-3-3 Proteins / metabolism CDC2 Protein Kinase / metabolism Cell Cycle Proteins / metabolism* Cell Nucleolus / drug effects Cell Nucleolus / enzymology* Checkpoint Kinase 2 DNA Replication* / drug effects DNA-Binding Proteins / metabolism Green Fluorescent Proteins / metabolism Hydroxyurea / pharmacology Intracellular Signaling Peptides and Proteins / metabolism Kinetics Mutation / genetics Phosphoprotein Phosphatases / metabolism* Phosphorylation / drug effects Protein Binding / drug effects Protein Tyrosine Phosphatases / metabolism* Protein-Serine-Threonine Kinases / metabolism* Recombinant Fusion Proteins / metabolism Recombination, Genetic / genetics S Phase / drug effects Schizosaccharomyces / cytology* Schizosaccharomyces / drug effects Schizosaccharomyces / enzymology* Schizosaccharomyces pombe Proteins / metabolism*
IF 3.905
Times Cited 13
Yeast FY13580