DNA replication checkpoint control of Wee1 stability by vertebrate Hsl7

G2/M checkpoints prevent mitotic entry upon DNA damage or replication inhibition by targeting the Cdc2 regulators Cdc25 and Wee1. Although Wee1 protein stability is regulated by DNA-responsive checkpoints, the vertebrate pathways controlling Wee1 degradation have not been elucidated. In budding yeast, stability of the Wee1 homologue, Swe1, is controlled by a regulatory module consisting of the proteins Hsl1 and Hsl7 (histone synthetic lethal 1 and 7), which are targeted by the morphogenesis checkpoint to prevent Swe1 degradation when budding is inhibited. We report here the identification of Xenopus Hsl7 as a positive regulator of mitosis that is controlled, instead, by an entirely distinct checkpoint, the DNA replication checkpoint. Although inhibiting Hsl7 delayed mitosis, Hsl7 overexpression overrode the replication checkpoint, accelerating Wee1 destruction. Replication checkpoint activation disrupted Hsl7–Wee1 interactions, but binding was restored by active polo-like kinase. These data establish Hsl7 as a component of the replication checkpoint and reveal that similar cell cycle control modules can be co-opted for use by distinct checkpoints in different organsims.

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The Direct Binding of Mrc1, a Checkpoint Mediator, to Mcm6, a Replication Helicase, Is Essential for the Replication Checkpoint against Methyl Methanesulfonate-Induced Stress

Molecular and Cellular Biology ◽

10.1128/mcb.01934-08 ◽

2009 ◽

Vol 29 (18) ◽

pp. 5008-5019 ◽

Cited By ~ 43

Author(s):

Makiko Komata ◽

Masashige Bando ◽

Hiroyuki Araki ◽

Katsuhiko Shirahige

Keyword(s):

Amino Acid ◽

Dna Replication ◽

Terminal Region ◽

Methyl Methanesulfonate ◽

Checkpoint Activation ◽

Replication Checkpoint ◽

Hydroxyurea Treatment ◽

Dna Replication Checkpoint ◽

Direct Binding

ABSTRACT Mrc1 plays a role in mediating the DNA replication checkpoint. We surveyed replication elongation proteins that interact directly with Mrc1 and identified a replicative helicase, Mcm6, as a specific Mrc1-binding protein. The central portion of Mrc1, containing a conserved coiled-coil region, was found to be essential for interaction with the 168-amino-acid C-terminal region of Mcm6, and introduction of two amino acid substitutions in this C-terminal region abolished the interaction with Mrc1 in vivo. An mcm6 mutant bearing these substitutions showed a severe defect in DNA replication checkpoint activation in response to stress caused by methyl methanesulfonate. Interestingly, the mutant did not show any defect in DNA replication checkpoint activation in response to hydroxyurea treatment. The phenotype of the mcm6 mutant was suppressed when the mutant protein was physically fused with Mrc1. These results strongly suggest for the first time that an Mcm helicase acts as a checkpoint sensor for methyl methanesulfonate-induced DNA damage through direct binding to the replication checkpoint mediator Mrc1.

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DNA Replication Checkpoint Control Mediated by the Spindle Checkpoint Protein Mad2p in Fission Yeast

Journal of Biological Chemistry ◽

10.1074/jbc.m403231200 ◽

2004 ◽

Vol 279 (45) ◽

pp. 47372-47378 ◽

Cited By ~ 22

Author(s):

Izumi Sugimoto ◽

Hiroshi Murakami ◽

Yuko Tonami ◽

Akihiko Moriyama ◽

Makoto Nakanishi

Keyword(s):

Dna Replication ◽

Fission Yeast ◽

Spindle Checkpoint ◽

Checkpoint Control ◽

Replication Checkpoint ◽

Checkpoint Protein ◽

Dna Replication Checkpoint

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Cdc18p can block mitosis by two independent mechanisms

Journal of Cell Science ◽

10.1242/jcs.111.20.3101 ◽

1998 ◽

Vol 111 (20) ◽

pp. 3101-3108 ◽

Cited By ~ 2

Author(s):

E. Greenwood ◽

H. Nishitani ◽

P. Nurse

Keyword(s):

Dna Replication ◽

S Phase ◽

Checkpoint Control ◽

Replication Checkpoint ◽

Mitotic Kinase ◽

C Terminus ◽

N Terminus ◽

Dna Replication Checkpoint ◽

Checkpoint Genes

The DNA replication checkpoint is required to maintain the integrity of the genome, inhibiting mitosis until S phase has been successfully completed. The checkpoint preventing premature mitosis in Schizosaccharomyces pombe relies on phosphorylation of the tyrosine-15 residue on cdc2p to prevent its activation and hence mitosis. The cdc18 gene is essential for both generating the DNA replication checkpoint and the initiation of S phase, thus providing a key role for the overall control and coordination of the cell cycle. We show that the C terminus of the protein is capable of both initiating DNA replication and the checkpoint function of cdc18p. The C terminus of cdc18p acts upstream of the DNA replication checkpoint genes rad1, rad3, rad9, rad17, hus1 and cut5 and requires the wee1p/mik1p tyrosine kinases to block mitosis. The N terminus of cdc18p can also block mitosis but does so in the absence of the DNA replication checkpoint genes and the wee1p/mik1p kinases therefore acting downstream of these genes. Because the N terminus of cdc18p associates with cdc2p in vivo, we suggest that by binding the cdc2p/cdc13p mitotic kinase directly, it exerts an effect independently of the normal checkpoint control, probably in an unphysiological manner.

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MDC1 collaborates with TopBP1 in DNA replication checkpoint control

The Journal of Cell Biology ◽

10.1083/jcb.201010026 ◽

2011 ◽

Vol 193 (2) ◽

pp. 267-273 ◽

Cited By ~ 66

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.

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Structural Insights into Recognition of MDC1 by TopBP1 in DNA Replication Checkpoint Control

Structure ◽

10.1016/j.str.2013.06.015 ◽

2013 ◽

Vol 21 (8) ◽

pp. 1450-1459 ◽

Cited By ~ 17

Author(s):

Charles Chung Yun Leung ◽

Luxin Sun ◽

Zihua Gong ◽

Michael Burkat ◽

Ross Edwards ◽

...

Keyword(s):

Dna Replication ◽

Checkpoint Control ◽

Replication Checkpoint ◽

Dna Replication Checkpoint ◽

Structural Insights

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Separable functions of Tof1/Timeless in intra-S-checkpoint signalling, replisome stability and DNA topological stress

Nucleic Acids Research ◽

10.1093/nar/gkaa963 ◽

2020 ◽

Vol 48 (21) ◽

pp. 12169-12187

Author(s):

Rose Westhorpe ◽

Andrea Keszthelyi ◽

Nicola E Minchell ◽

David Jones ◽

Jonathan Baxter

Keyword(s):

Saccharomyces Cerevisiae ◽

Dna Replication ◽

Replication Stress ◽

Dna Helicase ◽

The Other ◽

Checkpoint Activation ◽

Replication Checkpoint ◽

Binding Partner ◽

Dna Replication Checkpoint

Abstract The highly conserved Tof1/Timeless proteins minimise replication stress and promote normal DNA replication. They are required to mediate the DNA replication checkpoint (DRC), the stable pausing of forks at protein fork blocks, the coupling of DNA helicase and polymerase functions during replication stress (RS) and the preferential resolution of DNA topological stress ahead of the fork. Here we demonstrate that the roles of the Saccharomyces cerevisiae Timeless protein Tof1 in DRC signalling and resolution of DNA topological stress require distinct N and C terminal regions of the protein, whereas the other functions of Tof1 are closely linked to the stable interaction between Tof1 and its constitutive binding partner Csm3/Tipin. By separating the role of Tof1 in DRC from fork stabilisation and coupling, we show that Tof1 has distinct activities in checkpoint activation and replisome stability to ensure the viable completion of DNA replication following replication stress.

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Faculty Opinions recommendation of DNA replication checkpoint control of Wee1 stability by vertebrate Hsl7.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1023057.265694 ◽

2004 ◽

Author(s):

Jonathon Pines

Keyword(s):

Dna Replication ◽

Checkpoint Control ◽

Replication Checkpoint ◽

Dna Replication Checkpoint

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The Spd1p S phase inhibitor can activate the DNA replication checkpoint pathway in fission yeast

Journal of Cell Science ◽

10.1242/jcs.113.23.4341 ◽

2000 ◽

Vol 113 (23) ◽

pp. 4341-4350 ◽

Cited By ~ 2

Author(s):

A. Borgne ◽

P. Nurse

Keyword(s):

Cell Cycle ◽

Dna Replication ◽

Cell Cycle Progression ◽

S Phase ◽

Checkpoint Control ◽

Replication Checkpoint ◽

Checkpoint Pathway ◽

Dna Replication Checkpoint ◽

A Cell ◽

Checkpoint Genes

Spd1p (for S phase delayed) is a cell cycle inhibitor in Schizosaccharomyces pombe. Spd1p overexpression blocks the onset of both S phase and mitosis. In this study, we have investigated the mechanisms by which Spd1p overexpression blocks cell cycle progression, focussing on the block over mitotic onset. High levels of Spd1p lead to an increase in Y15 phosphorylation of Cdc2p and we show that the block over G(2) requires the Wee1p kinase and is dependent on the rad and chk1/cds1 checkpoint genes. We propose that high levels of Spd1p in G(2) cells activate the DNA replication checkpoint control, which leads to a Wee1p-dependent increase of Cdc2p Y15 phosphorylation blocking onset of mitosis. The Spd1p block at S phase onset may act by interfering directly with DNA replication, and also activates the G(2)rad/hus checkpoint pathway to block mitosis.

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