We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Characterization of the role of a trimeric protein phosphatase complex in recovery from cisplatin-induced versus noncrosslinking DNA damage.
- Authors
Vásquez-Martin, Cristina; Rouse, John; Cohen, Patricia T. W.
- Abstract
Cisplatin ( cis-diamminedichloroplatinum) and related chemotherapeutic DNA-crosslinking agents are widely used to treat human cancers. Saccharomyces cerevisiae with separate deletions of the genes encoding the trimeric protein serine/threonine phosphatase (Pph)3p–platinum sensitivity (Psy)4p–Psy2p complex, are more sensitive than the isogenic wild-type (WT) strain to cisplatin. We show here that cisplatin causes an enhanced intra-S-phase cell cycle delay in these three deletion mutants. The C-terminal tail of histone 2AX (H2AX) is hyperphosphorylated in the same mutants, and Pph3p is found to interact with phosphorylated H2AX (γH2AX). After cisplatin treatment is terminated, pph3Δ, psy4Δ and psy2Δ mutants are delayed as compared with the WT strain in the dephosphorylation of Rad53p. In contrast, only pph3Δ and psy2Δ cells are more sensitive than WT cells to methylmethanesulfonate, a noncrosslinking DNA-alkylating agent that is known to cause a Rad53p-dependent intra-S-phase cell cycle delay. Dephosphorylation of Rad53p and the recovery of chromosome replication are delayed in the same mutants, but not in psy4Δ cells. By comparison with their mammalian orthologues, the regulatory subunit Psy4p is likely to inhibit Pph3p catalytic activity. The presence of a weak but active Pph3p–Psy2p complex may allow psy4Δ cells to escape from the Rad53p-mediated cell cycle arrest. Overall, our data suggest that the trimeric Pph3p–Psy4p–Psy2p complex may dephosphorylate both γH2AX and Rad53p, the differences lying in the more stable interaction of the Pph3 phosphatase with γH2AX as opposed to a transient interaction with Rad53p.
- Publication
FEBS Journal, 2008, Vol 275, Issue 16, p4211
- ISSN
1742-464X
- Publication type
Academic Journal
- DOI
10.1111/j.1742-4658.2008.06568.x