Abstract
Saccharomyces cells with one unrepaired double-strand break (DSB) adapt after checkpoint-mediated G2/M arrest. Adaptation is accompanied by loss of Rad53p checkpoint kinase activity and Chk1p phosphorylation. Rad53p kinase remains elevated in yku70delta and cdc5-ad cells that fail to adapt. Permanent G2/M arrest in cells with increased single-stranded DNA is suppressed by the rfa1-t11 mutation, but this RPA mutation does not suppress permanent arrest in cdc5-ad cells. Checkpoint kinase activation and inactivation can be followed in G2-arrested cells, but there is no kinase activation in G1-arrested cells. We conclude that activation of the checkpoint kinases in response to a single DNA break is cell cycle regulated and that adaptation is an active process by which these kinases are inactivated.
MeSH Terms
Adaptation, Biological/genetics
Anaphase
Antigens, Nuclear
Cell Cycle
Cell Cycle Proteins/genetics,metabolism
Checkpoint Kinase 1
Checkpoint Kinase 2
DNA Damage/genetics
DNA Helicases
DNA, Fungal/metabolism
DNA-Binding Proteins/genetics,metabolism
Enzyme Activation
Fungal Proteins/metabolism
G2 Phase
Gene Expression
Intracellular Signaling Peptides and Proteins
Kinetics
Ku Autoantigen
Mitosis
Mutation
Nuclear Proteins/genetics,metabolism
Phosphorylation
Protein Kinases/metabolism
Protein Serine-Threonine Kinases
RNA-Binding Proteins
Recombination, Genetic
Replication Protein A
Saccharomyces cerevisiae/cytology,enzymology,genetics,metabolism
Saccharomyces cerevisiae Proteins
Sequence Homology, Nucleic Acid
Chemicals
Antigens, Nuclear
CEF1 protein, S cerevisiae
Cell Cycle Proteins
DNA, Fungal
DNA-Binding Proteins
Fungal Proteins
Intracellular Signaling Peptides and Proteins
Nuclear Proteins
RNA-Binding Proteins
Replication Protein A
Saccharomyces cerevisiae Proteins
high affinity DNA-binding factor, S cerevisiae
Protein Kinases
Checkpoint Kinase 2
Checkpoint Kinase 1
MEC1 protein, S cerevisiae
Protein Serine-Threonine Kinases
RAD53 protein, S cerevisiae
DNA Helicases
XRCC5 protein, human
Xrcc6 protein, human
Ku Autoantigen
Authors & Affiliations
5 authors, click to expand affiliations / ORCID
Pellicioli A
Istituto F.I.R.C. di Oncologia Molecolare and, Dipartimento di Genetica e di Biologia dei, Microrganismi, Universita' degli Studi di Milano, 20133, Milan, Italy.
Lee S E
Lucca C
Foiani M
Haber J E