» Articles » PMID: 21173116

Chk1 Inhibits Replication Factory Activation but Allows Dormant Origin Firing in Existing Factories

Overview
Journal J Cell Biol
Specialty Cell Biology
Date 2010 Dec 22
PMID 21173116
Citations 124
Authors
Affiliations
Soon will be listed here.
Abstract

Replication origins are licensed by loading MCM2-7 hexamers before entry into S phase. However, only ∼10% of licensed origins are normally used in S phase, with the others remaining dormant. When fork progression is inhibited, dormant origins initiate nearby to ensure that all of the DNA is eventually replicated. In apparent contrast, replicative stress activates ataxia telangiectasia and rad-3-related (ATR) and Chk1 checkpoint kinases that inhibit origin firing. In this study, we show that at low levels of replication stress, ATR/Chk1 predominantly suppresses origin initiation by inhibiting the activation of new replication factories, thereby reducing the number of active factories. At the same time, inhibition of replication fork progression allows dormant origins to initiate within existing replication factories. The inhibition of new factory activation by ATR/Chk1 therefore redirects replication toward active factories where forks are inhibited and away from regions that have yet to start replication. This minimizes the deleterious consequences of fork stalling and prevents similar problems from arising in unreplicated regions of the genome.

Citing Articles

Mechanisms of tandem duplication in the cancer genome.

Scully R, Glodzik D, Menghi F, Liu E, Zhang C DNA Repair (Amst). 2025; 145:103802.

PMID: 39742573 PMC: 11843477. DOI: 10.1016/j.dnarep.2024.103802.


Telomere maintenance and the DNA damage response: a paradoxical alliance.

Harman A, Bryan T Front Cell Dev Biol. 2024; 12:1472906.

PMID: 39483338 PMC: 11524846. DOI: 10.3389/fcell.2024.1472906.


A TRilogy of ATR's Non-Canonical Roles Throughout the Cell Cycle and Its Relation to Cancer.

Joo Y, Ramirez C, Kabeche L Cancers (Basel). 2024; 16(20).

PMID: 39456630 PMC: 11506335. DOI: 10.3390/cancers16203536.


A PRMT5-ZNF326 axis mediates innate immune activation upon replication stress.

Hoang P, Torre D, Jaynes P, Ho J, Mohammed K, Alvstad E Sci Adv. 2024; 10(23):eadm9589.

PMID: 38838142 PMC: 11804791. DOI: 10.1126/sciadv.adm9589.


Quantity and quality of minichromosome maintenance protein complexes couple replication licensing to genome integrity.

Yadav A, Polasek-Sedlackova H Commun Biol. 2024; 7(1):167.

PMID: 38336851 PMC: 10858283. DOI: 10.1038/s42003-024-05855-w.


References
1.
Ibarra A, Schwob E, Mendez J . Excess MCM proteins protect human cells from replicative stress by licensing backup origins of replication. Proc Natl Acad Sci U S A. 2008; 105(26):8956-61. PMC: 2449346. DOI: 10.1073/pnas.0803978105. View

2.
Lambert S, Carr A . Checkpoint responses to replication fork barriers. Biochimie. 2005; 87(7):591-602. DOI: 10.1016/j.biochi.2004.10.020. View

3.
Tercero J, Diffley J . Regulation of DNA replication fork progression through damaged DNA by the Mec1/Rad53 checkpoint. Nature. 2001; 412(6846):553-7. DOI: 10.1038/35087607. View

4.
Blow J, Dutta A . Preventing re-replication of chromosomal DNA. Nat Rev Mol Cell Biol. 2005; 6(6):476-86. PMC: 2688777. DOI: 10.1038/nrm1663. View

5.
Dimitrova D, Gilbert D . Temporally coordinated assembly and disassembly of replication factories in the absence of DNA synthesis. Nat Cell Biol. 2000; 2(10):686-94. PMC: 1255923. DOI: 10.1038/35036309. View