Gap-filling and bypass at the replication fork are both active mechanisms for tolerance of low-dose ultraviolet-induced DNA damage in the human genome

AbstractTranslesion synthesis (TLS) is a highly conserved mutagenic DNA lesion tolerance pathway, which employs specialized, low-fidelity DNA polymerases to synthesize across lesions. Current models suggest that activity of these polymerases is predominantly associated with ongoing replication, functioning either at or behind the replication fork. Here we provide evidence for DNA damage-dependent function of a specialized polymerase, DnaE2, in replication-independent conditions. We develop an assay to follow lesion repair in non-replicating Caulobacter and observe that components of the replication machinery localize on DNA in response to damage. These localizations persist in the absence of DnaE2 or if catalytic activity of the polymerase is mutated. Single-stranded DNA gaps for SSB binding and low-fidelity polymerase-mediated synthesis are generated by nucleotide excision repair, as replisome components fail to localize in its absence. This mechanism of gap-filling facilitates cell cycle restoration when cells are released into replication-permissive conditions. Thus, such cross-talk (between activity of NER and specialized polymerases in subsequent gap-filling) helps preserve genome integrity and enhances survival in a replication-independent manner.

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Coordination between nucleotide excision repair and specialized polymerase DnaE2 action enables DNA damage survival in non-replicating bacteria

eLife ◽

10.7554/elife.67552 ◽

2021 ◽

Vol 10 ◽

Author(s):

Asha Mary Joseph ◽

Saheli Daw ◽

Ismath Sadhir ◽

Anjana Badrinarayanan

Keyword(s):

Dna Damage ◽

Nucleotide Excision Repair ◽

Replication Fork ◽

Excision Repair ◽

Genome Integrity ◽

Replication Machinery ◽

Gap Filling ◽

Independent Manner ◽

Dna Lesion ◽

Nucleotide Excision

Translesion synthesis (TLS) is a highly conserved mutagenic DNA lesion tolerance pathway, which employs specialized, low-fidelity DNA polymerases to synthesize across lesions. Current models suggest that activity of these polymerases is predominantly associated with ongoing replication, functioning either at or behind the replication fork. Here we provide evidence for DNA damage-dependent function of a specialized polymerase, DnaE2, in replication-independent conditions. We develop an assay to follow lesion repair in non-replicating Caulobacter and observe that components of the replication machinery localize on DNA in response to damage. These localizations persist in the absence of DnaE2 or if catalytic activity of this polymerase is mutated. Single-stranded DNA gaps for SSB binding and low-fidelity polymerase-mediated synthesis are generated by nucleotide excision repair, as replisome components fail to localize in the absence of NER. This mechanism of gap-filling facilitates cell cycle restoration when cells are released into replication-permissive conditions. Thus, such cross-talk (between activity of NER and specialized polymerases in subsequent gap-filling) helps preserve genome integrity and enhances survival in a replication-independent manner.

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Faculty Opinions recommendation of DNA damage-induced replication fork regression and processing in Escherichia coli.

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

10.3410/f.1011878.186471 ◽

2003 ◽

Author(s):

Martin Marinus

Keyword(s):

Escherichia Coli ◽

Dna Damage ◽

Replication Fork ◽

Fork Regression

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Faculty Opinions recommendation of The RecQ helicase WRN is required for normal replication fork progression after DNA damage or replication fork arrest.

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

10.3410/f.1103219.559217 ◽

2008 ◽

Author(s):

Philippe Pasero

Keyword(s):

Dna Damage ◽

Replication Fork ◽

Recq Helicase ◽

Replication Fork Progression ◽

Replication Fork Arrest

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DNA damage signaling guards against perturbation of cyclin D1 expression triggered by low-dose long-term fractionated radiation

Oncogenesis ◽

10.1038/oncsis.2014.48 ◽

2014 ◽

Vol 3 (12) ◽

pp. e132-e132 ◽

Cited By ~ 10

Author(s):

T Shimura ◽

J Kobayashi ◽

K Komatsu ◽

N Kunugita

Keyword(s):

Dna Damage ◽

Cyclin D1 ◽

Low Dose ◽

Dna Damage Signaling ◽

Fractionated Radiation

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A transcription-based mechanism for oncogenic β-catenin-induced lethality in BRCA1/2-deficient cells

Nature Communications ◽

10.1038/s41467-021-25215-0 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Rebecca A. Dagg ◽

Gijs Zonderland ◽

Emilia Puig Lombardi ◽

Giacomo G. Rossetti ◽

Florian J. Groelly ◽

...

Keyword(s):

Dna Damage ◽

Replication Fork ◽

High Throughput Sequencing ◽

Germline Mutations ◽

Cdk Inhibitor ◽

Rna Seq ◽

Gene Encoding ◽

Origin Firing ◽

Replication Fork Progression ◽

Transcriptional Alterations

AbstractBRCA1 or BRCA2 germline mutations predispose to breast, ovarian and other cancers. High-throughput sequencing of tumour genomes revealed that oncogene amplification and BRCA1/2 mutations are mutually exclusive in cancer, however the molecular mechanism underlying this incompatibility remains unknown. Here, we report that activation of β-catenin, an oncogene of the WNT signalling pathway, inhibits proliferation of BRCA1/2-deficient cells. RNA-seq analyses revealed β-catenin-induced discrete transcriptome alterations in BRCA2-deficient cells, including suppression of CDKN1A gene encoding the CDK inhibitor p21. This accelerates G1/S transition, triggering illegitimate origin firing and DNA damage. In addition, β-catenin activation accelerates replication fork progression in BRCA2-deficient cells, which is critically dependent on p21 downregulation. Importantly, we find that upregulated p21 expression is essential for the survival of BRCA2-deficient cells and tumours. Thus, our work demonstrates that β-catenin toxicity in cancer cells with compromised BRCA1/2 function is driven by transcriptional alterations that cause aberrant replication and inflict DNA damage.

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