scholarly journals Mrc1 and DNA Polymerase ɛ Function Together in Linking DNA Replication and the S Phase Checkpoint

2008 ◽  
Vol 32 (1) ◽  
pp. 106-117 ◽  
Author(s):  
Huiqiang Lou ◽  
Makiko Komata ◽  
Yuki Katou ◽  
Zhiyun Guan ◽  
Clara C. Reis ◽  
...  
Cell ◽  
1995 ◽  
Vol 80 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Tony A Navas ◽  
Zheng Zhou ◽  
Stephen J Elledge

2005 ◽  
Vol 168 (7) ◽  
pp. 999-1012 ◽  
Author(s):  
Jeff Bachant ◽  
Shannon R. Jessen ◽  
Sarah E. Kavanaugh ◽  
Candida S. Fielding

The budding yeast S phase checkpoint responds to hydroxyurea-induced nucleotide depletion by preventing replication fork collapse and the segregation of unreplicated chromosomes. Although the block to chromosome segregation has been thought to occur by inhibiting anaphase, we show checkpoint-defective rad53 mutants undergo cycles of spindle extension and collapse after hydroxyurea treatment that are distinct from anaphase cells. Furthermore, chromatid cohesion, whose dissolution triggers anaphase, is dispensable for S phase checkpoint arrest. Kinetochore–spindle attachments are required to prevent spindle extension during replication blocks, and chromosomes with two centromeres or an origin of replication juxtaposed to a centromere rescue the rad53 checkpoint defect. These observations suggest that checkpoint signaling is required to generate an inward force involved in maintaining preanaphase spindle integrity during DNA replication distress. We propose that by promoting replication fork integrity under these conditions Rad53 ensures centromere duplication. Replicating chromosomes can then bi-orient in a cohesin-independent manner to restrain untimely spindle extension.


2012 ◽  
Vol 41 (1) ◽  
pp. 229-241 ◽  
Author(s):  
Elisa Zucca ◽  
Federica Bertoletti ◽  
Ursula Wimmer ◽  
Elena Ferrari ◽  
Giuliano Mazzini ◽  
...  

2004 ◽  
Vol 24 (21) ◽  
pp. 9568-9579 ◽  
Author(s):  
Yanjiao Zhou ◽  
Teresa S.-F. Wang

ABSTRACT DNA replication depends critically upon chromatin structure. Little is known about how the replication complex overcomes the nucleosome packages in chromatin during DNA replication. To address this question, we investigate factors that interact in vivo with the principal initiation DNA polymerase, DNA polymerase α (Polα). The catalytic subunit of budding yeast Polα (Pol1p) has been shown to associate in vitro with the Spt16p-Pob3p complex, a component of the nucleosome reorganization system required for both replication and transcription, and with a sister chromatid cohesion factor, Ctf4p. Here, we show that an N-terminal region of Polα (Pol1p) that is evolutionarily conserved among different species interacts with Spt16p-Pob3p and Ctf4p in vivo. A mutation in a glycine residue in this N-terminal region of POL1 compromises the ability of Pol1p to associate with Spt16p and alters the temporal ordered association of Ctf4p with Pol1p. The compromised association between the chromatin-reorganizing factor Spt16p and the initiating DNA polymerase Pol1p delays the Pol1p assembling onto and disassembling from the late-replicating origins and causes a slowdown of S-phase progression. Our results thus suggest that a coordinated temporal and spatial interplay between the conserved N-terminal region of the Polα protein and factors that are involved in reorganization of nucleosomes and promoting establishment of sister chromatin cohesion is required to facilitate S-phase progression.


2009 ◽  
Vol 20 (17) ◽  
pp. 3953-3964 ◽  
Author(s):  
Eric Lau ◽  
Gary G. Chiang ◽  
Robert T. Abraham ◽  
Wei Jiang

The DNA replication machinery plays additional roles in S phase checkpoint control, although the identities of the replication proteins involved in checkpoint activation remain elusive. Here, we report that depletion of the prereplicative complex (pre-RC) protein Cdc6 causes human nontransformed diploid cells to arrest nonlethally in G1-G1/S and S phase, whereas multiple cancer cell lines undergo G1-G1/S arrest and cell death. These divergent phenotypes are dependent on the activation, or lack thereof, of an ataxia telangiectasia and Rad3-related (ATR)-dependent S phase checkpoint that inhibits replication fork progression. Although pre-RC deficiency induces chromatin structural alterations in both nontransformed and cancer cells that normally lead to ATR checkpoint activation, the sensor mechanisms in cancer cells seem to be compromised such that higher levels of DNA replication stress/damage are required to trigger checkpoint response. Our results suggest that therapy-induced disruption of pre-RC function might exert selective cytotoxic effects on tumor cells in human patients.


2013 ◽  
Vol 42 (2) ◽  
pp. 926-940 ◽  
Author(s):  
R. A. Frum ◽  
S. Singh ◽  
C. Vaughan ◽  
N. D. Mukhopadhyay ◽  
S. R. Grossman ◽  
...  

2008 ◽  
Vol 19 (10) ◽  
pp. 4374-4382 ◽  
Author(s):  
Ling Yin ◽  
Alexandra Monica Locovei ◽  
Gennaro D'Urso

In the fission yeast, Schizosaccharomyces pombe, blocks to DNA replication elongation trigger the intra-S phase checkpoint that leads to the activation of the Cds1 kinase. Cds1 is required to both prevent premature entry into mitosis and to stabilize paused replication forks. Interestingly, although Cds1 is essential to maintain the viability of mutants defective in DNA replication elongation, mutants defective in DNA replication initiation require the Chk1 kinase. This suggests that defects in DNA replication initiation can lead to activation of the DNA damage checkpoint independent of the intra-S phase checkpoint. This might result from reduced origin firing that leads to an increase in replication fork stalling or replication fork collapse that activates the G2 DNA damage checkpoint. We refer to the Chk1-dependent, Cds1-independent phenotype as the rid phenotype (for replication initiation defective). Chk1 is active in rid mutants, and rid mutant viability is dependent on the DNA damage checkpoint, and surprisingly Mrc1, a protein required for activation of Cds1. Mutations in Mrc1 that prevent activation of Cds1 have no effect on its ability to support rid mutant viability, suggesting that Mrc1 has a checkpoint-independent role in maintaining the viability of mutants defective in DNA replication initiation.


Sign in / Sign up

Export Citation Format

Share Document