DNA polymerase ?-dependent DNA synthesis at stalled replication forks is important for CHK1 activation.

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 ?) contributes to the replication checkpoint response and is required for recovery after replication stress. We found that Pol ? 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 ? interacts with the Rad9 subunit of the 9-1-1 complex. Finally, we show that this novel checkpoint function of Pol ? is required for the maintenance of genomic stability and cell proliferation in unstressed human cells.

SUBMITTER: Betous R 

PROVIDER: S-EPMC3730229 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature