DNA polymerase κ-dependent DNA synthesis at stalled replication forks is important for CHK1 activation.
EMBO J 2013;
32:2172-85. [PMID:
23799366 PMCID:
PMC3730229 DOI:
10.1038/emboj.2013.148]
[Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 06/04/2013] [Indexed: 02/04/2023] Open
Abstract
Formation of primed single-stranded DNA at stalled replication forks triggers activation of the replication checkpoint signalling cascade resulting in the ATR-mediated phosphorylation of the Chk1 protein kinase, thus preventing genomic instability. By using siRNA-mediated depletion in human cells and immunodepletion and reconstitution experiments in Xenopus egg extracts, we report that the Y-family translesion (TLS) DNA polymerase kappa (Pol κ) contributes to the replication checkpoint response and is required for recovery after replication stress. We found that Pol κ is implicated in the synthesis of short DNA intermediates at stalled forks, facilitating the recruitment of the 9-1-1 checkpoint clamp. Furthermore, we show that Pol κ interacts with the Rad9 subunit of the 9-1-1 complex. Finally, we show that this novel checkpoint function of Pol κ is required for the maintenance of genomic stability and cell proliferation in unstressed human cells.
A vertebrate translesion synthesis DNA polymerase broadly contributes to checkpoint-activating primer synthesis at stalled replication forks, a role previously ascribed only to replicative polymerases.
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