The DNA replication checkpoint response stabilizes stalled replication forks

Nature ◽  
2001 ◽  
Vol 412 (6846) ◽  
pp. 557-561 ◽  
Author(s):  
Massimo Lopes ◽  
Cecilia Cotta-Ramusino ◽  
Achille Pellicioli ◽  
Giordano Liberi ◽  
Paolo Plevani ◽  
...  
Keyword(s):  
Dna Replication ◽  
Replication Forks ◽  
Replication Checkpoint ◽  
Checkpoint Response ◽  
Dna Replication Checkpoint ◽  
Stalled Replication Forks

Overlapping Roles of the Spindle Assembly and DNA Damage Checkpoints in the Cell-Cycle Response to Altered Chromosomes in Saccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 161 (2) ◽  
pp. 521-534
Author(s):  
Peter M Garber ◽  
Jasper Rine
Keyword(s):  
Dna Damage ◽  
Dna Replication ◽  
Spindle Checkpoint ◽  
Dna Lesions ◽  
Replication Proteins ◽  
Replication Checkpoint ◽  
Dna Damage Checkpoints ◽  
Dna Replication Checkpoint ◽  
Mcm Proteins ◽  
Stalled Replication Forks

Abstract The MAD2-dependent spindle checkpoint blocks anaphase until all chromosomes have achieved successful bipolar attachment to the mitotic spindle. The DNA damage and DNA replication checkpoints block anaphase in response to DNA lesions that may include single-stranded DNA and stalled replication forks. Many of the same conditions that activate the DNA damage and DNA replication checkpoints also activated the spindle checkpoint. The mad2Δ mutation partially relieved the arrest responses of cells to mutations affecting the replication proteins Mcm3p and Pol1p. Thus a previously unrecognized aspect of spindle checkpoint function may be to protect cells from defects in DNA replication. Furthermore, in cells lacking either the DNA damage or the DNA replication checkpoints, the spindle checkpoint contributed to the arrest responses of cells to the DNA-damaging agent methyl methanesulfonate, the replication inhibitor hydroxyurea, and mutations affecting Mcm2p and Orc2p. Thus the spindle checkpoint was sensitive to a wider range of chromosomal perturbations than previously recognized. Finally, the DNA replication checkpoint did not contribute to the arrests of cells in response to mutations affecting ORC, Mcm proteins, or DNA polymerase δ. Thus the specificity of this checkpoint may be more limited than previously recognized.

scholarly journals Colocalization of Mec1 and Mrc1 is sufficient for Rad53 phosphorylation in vivo

2012 ◽  
Vol 23 (6) ◽  
pp. 1058-1067 ◽  
Author(s):  
Theresa J. Berens ◽  
David P. Toczyski
Keyword(s):  
Dna Replication ◽  
Double Strand Breaks ◽  
Sensor Kinase ◽  
Replication Forks ◽  
Checkpoint Activation ◽  
Replication Checkpoint ◽  
Strand Breaks ◽  
Crucial Step ◽  
Stalled Replication Forks

When DNA is damaged or DNA replication goes awry, cells activate checkpoints to allow time for damage to be repaired and replication to complete. In Saccharomyces cerevisiae, the DNA damage checkpoint, which responds to lesions such as double-strand breaks, is activated when the lesion promotes the association of the sensor kinase Mec1 and its targeting subunit Ddc2 with its activators Ddc1 (a member of the 9-1-1 complex) and Dpb11. It has been more difficult to determine what role these Mec1 activators play in the replication checkpoint, which recognizes stalled replication forks, since Dpb11 has a separate role in DNA replication itself. Therefore we constructed an in vivo replication-checkpoint mimic that recapitulates Mec1-dependent phosphorylation of the effector kinase Rad53, a crucial step in checkpoint activation. In the endogenous replication checkpoint, Mec1 phosphorylation of Rad53 requires Mrc1, a replisome component. The replication-checkpoint mimic requires colocalization of Mrc1-LacI and Ddc2-LacI and is independent of both Ddc1 and Dpb11. We show that these activators are also dispensable for Mec1 activity and cell survival in the endogenous replication checkpoint but that Ddc1 is absolutely required in the absence of Mrc1. We propose that colocalization of Mrc1 and Mec1 is the minimal signal required to activate the replication checkpoint.

scholarly journals MDC1 collaborates with TopBP1 in DNA replication checkpoint control

2011 ◽  
Vol 193 (2) ◽  
pp. 267-273 ◽  
Author(s):  
Jiadong Wang ◽  
Zihua Gong ◽  
Junjie Chen
Keyword(s):  
Dna Replication ◽  
Cellular Response ◽  
Checkpoint Control ◽  
Dna Double Strand Breaks ◽  
Replication Checkpoint ◽  
Strand Breaks ◽  
Major Player ◽  
Dna Replication Checkpoint ◽  
Cellular Dna ◽  
Stalled Replication Forks

Human TopBP1 is a major player in the control of the DNA replication checkpoint. In this study, we identified MDC1, a key checkpoint protein involved in the cellular response to DNA double-strand breaks, as a TopBP1-associated protein. The specific TopBP1–MDC1 interaction is mediated by the fifth BRCT domain of TopBP1 and the Ser-Asp-Thr (SDT) repeats of MDC1. In addition, we demonstrated that TopBP1 accumulation at stalled replication forks is promoted by the H2AX/MDC1 signaling cascade. Moreover, MDC1 is important for ATR-dependent Chk1 activation in response to replication stress. Collectively, our data suggest that MDC1 facilitates several important steps in both cellular DNA damage response and the DNA replication checkpoint.

Dpb11/TopBP1 plays distinct roles in DNA replication, checkpoint response and homologous recombination

DNA Repair ◽  
2011 ◽  
Vol 10 (2) ◽  
pp. 210-224 ◽  
Author(s):  
Susanne M. Germann ◽  
Vibe H. Oestergaard ◽  
Caroline Haas ◽  
Pauline Salis ◽  
Akira Motegi ◽  
...  
Keyword(s):  
Dna Replication ◽  
Homologous Recombination ◽  
Replication Checkpoint ◽  
Checkpoint Response ◽  
Dna Replication Checkpoint

scholarly journals The yeast Sgs1p helicase acts upstream of Rad53p in the DNA replication checkpoint and colocalizes with Rad53p in S-phase-specific foci

2000 ◽  
Vol 14 (1) ◽  
pp. 81-96 ◽  
Author(s):  
Christian Frei ◽  
Susan M. Gasser
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Replication Fork ◽  
Dna Helicase ◽  
S Phase ◽  
Replication Checkpoint ◽  
Checkpoint Response ◽  
Replication Fork Progression ◽  
Cycle Arrest ◽  
Dna Replication Checkpoint

We have examined the cellular function of Sgs1p, a nonessential yeast DNA helicase, homologs of which are implicated in two highly debilitating hereditary human diseases (Werner's and Bloom's syndromes). We show that Sgs1p is an integral component of the S-phase checkpoint response in yeast, which arrests cells due to DNA damage or blocked fork progression during DNA replication. DNA polε and Sgs1p are found in the same epistasis group and act upstream of Rad53p to signal cell cycle arrest when DNA replication is perturbed. Sgs1p is tightly regulated through the cell cycle, accumulates in S phase and colocalizes with Rad53p in S-phase-specific foci, even in the absence of fork arrest. The association of Rad53p with a chromatin subfraction is Sgs1p dependent, suggesting an important role for the helicase in the signal-transducing pathway that monitors replication fork progression.

scholarly journals DDK has a primary role in processing stalled replication forks to initiate downstream checkpoint signaling

2017 ◽  
Author(s):  
Nanda Kumar Sasi ◽  
Flavie Coquel ◽  
Yea-Lih Lin ◽  
Jeffrey P MacKeigan ◽  
Philippe Pasero ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Primary Role ◽  
Replication Forks ◽  
M Cell ◽  
Replication Checkpoint ◽  
Checkpoint Signaling ◽  
Checkpoint Response ◽  
Cycle Arrest ◽  
Stalled Replication Forks

AbstractCDC7-DBF4 kinase (DDK) is required to initiate DNA replication in eukaryotes by activating the replicative MCM helicase. DDK has also been reported to have diverse and sometimes conflicting roles in the replication checkpoint response in various organisms but the underlying mechanisms are far from settled. Here we show that human DDK promotes limited resection of newly synthesized DNA at stalled replication forks or sites of DNA damage to initiate replication checkpoint signaling. DDK is also required for efficient fork restart and G2/M cell cycle arrest. DDK exhibits genetic interactions with the ssDNA exonuclease EXO1, and we show that EXO1 is also required for nascent strand degradation following exposure to HU, raising the possibility that DDK regulates EXO1 directly. Thus, DDK has a primary and previously undescribed role in the replication checkpoint to promote ssDNA accumulation at stalled forks, which is required to initiate a robust checkpoint response and cell cycle arrest to maintain genome integrity.

scholarly journals Mcm2-7 Is an Active Player in the DNA Replication Checkpoint Signaling Cascade via Proposed Modulation of Its DNA Gate

2015 ◽  
Vol 35 (12) ◽  
pp. 2131-2143 ◽  
Author(s):  
Feng-Ling Tsai ◽  
Sriram Vijayraghavan ◽  
Joseph Prinz ◽  
Heather K. MacAlpine ◽  
David M. MacAlpine ◽  
...  
Keyword(s):  
Dna Replication ◽  
Conformational Change ◽  
Replication Checkpoint ◽  
Checkpoint Signaling ◽  
Kinase Activation ◽  
Checkpoint Response ◽  
Active Player ◽  
Dna Replication Checkpoint ◽  
Replication Factors

The DNA replication checkpoint (DRC) monitors and responds to stalled replication forks to prevent genomic instability. How core replication factors integrate into this phosphorylation cascade is incompletely understood. Here, through analysis of a uniquemcmallele targeting a specific ATPase active site (mcm2DENQ), we show that the Mcm2-7 replicative helicase has a novel DRC function as part of the signal transduction cascade. This allele exhibits normal downstream mediator (Mrc1) phosphorylation, implying DRC sensor kinase activation. However, the mutant also exhibits defective effector kinase (Rad53) activation and classic DRC phenotypes. Our previousin vitroanalysis showed that themcm2DENQmutation prevents a specific conformational change in the Mcm2-7 hexamer. We infer that this conformational change is required for its DRC role and propose that it allosterically facilitates Rad53 activation to ensure a replication-specific checkpoint response.

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