A local ATR-dependent checkpoint pathway is activated by a site-specific replication fork block in human cells.
Sana Ahmed-SeghirManisha JalanHelen E GrimsleyAman SharmaShyam TwayanaSettapong T KosiyatrakulChristopher ThompsonCarl L SchildkrautSimon N PowellPublished in: eLife (2023)
When replication forks encounter DNA lesions that cause polymerase stalling, a checkpoint pathway is activated. The ATR-dependent intra-S checkpoint pathway mediates detection and processing of sites of replication fork stalling to maintain genomic integrity. Several factors involved in the global checkpoint pathway have been identified, but the response to a single replication fork barrier (RFB) is poorly understood. We utilized the Escherichia coli -based Tus- Ter system in human MCF7 cells and showed that the Tus protein binding to TerB sequences creates an efficient site-specific RFB. The single fork RFB was sufficient to activate a local, but not global, ATR-dependent checkpoint response that leads to phosphorylation and accumulation of DNA damage sensor protein γH2AX, confined locally to within a kilobase of the site of stalling. These data support a model of local management of fork stalling, which allows global replication at sites other than the RFB to continue to progress without delay.
Keyphrases
- dna damage
- cell cycle
- dna repair
- escherichia coli
- oxidative stress
- dna damage response
- endothelial cells
- induced apoptosis
- protein protein
- amino acid
- cell proliferation
- cell cycle arrest
- small molecule
- dna methylation
- pseudomonas aeruginosa
- copy number
- binding protein
- cell death
- cystic fibrosis
- pi k akt
- deep learning
- klebsiella pneumoniae
- induced pluripotent stem cells