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 yku70Δ 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.
Original language | English (US) |
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Pages (from-to) | 293-300 |
Number of pages | 8 |
Journal | Molecular Cell |
Volume | 7 |
Issue number | 2 |
DOIs | |
State | Published - 2001 |
Externally published | Yes |
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology