The mechanism of replication stalling and recovery within repetitive DNA.
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ICR Authors
Authors
Casas-Delucchi, CS
Daza-Martin, M
Williams, SL
Coster, G
Daza-Martin, M
Williams, SL
Coster, G
Document Type
Journal Article
Date
2022-07-19
Date Accepted
2022-06-27
Abstract
Accurate chromosomal DNA replication is essential to maintain genomic stability. Genetic evidence suggests that certain repetitive sequences impair replication, yet the underlying mechanism is poorly defined. Replication could be directly inhibited by the DNA template or indirectly, for example by DNA-bound proteins. Here, we reconstitute replication of mono-, di- and trinucleotide repeats in vitro using eukaryotic replisomes assembled from purified proteins. We find that structure-prone repeats are sufficient to impair replication. Whilst template unwinding is unaffected, leading strand synthesis is inhibited, leading to fork uncoupling. Synthesis through hairpin-forming repeats is rescued by replisome-intrinsic mechanisms, whereas synthesis of quadruplex-forming repeats requires an extrinsic accessory helicase. DNA-induced fork stalling is mechanistically similar to that induced by leading strand DNA lesions, highlighting structure-prone repeats as an important potential source of replication stress. Thus, we propose that our understanding of the cellular response to replication stress may also be applied to DNA-induced replication stalling.
Citation
Nature Communications, 2022, 13 (1), pp. 3953 -
Source Title
Nature Communications
Publisher
NATURE PORTFOLIO
ISSN
2041-1723
eISSN
2041-1723
2041-1723
2041-1723
Collections
Research Team
Genome Replication