PrimPol is required for the maintenance of efficient nuclear and mitochondrial DNA replication in human cells

Bailey, Laura J, Bianchi, Julie and Doherty, Aidan J (2019) PrimPol is required for the maintenance of efficient nuclear and mitochondrial DNA replication in human cells. Nucleic Acids Research. ISSN 0305-1048 (Accepted)

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Abstract

Eukaryotic Primase-Polymerase (PrimPol) is an enzyme that maintains efficient DNA duplication by repriming replication restart downstream of replicase stalling lesions and structures. To elucidate the cellular requirements for PrimPol in human cells, we generated PrimPol-deleted cell lines and show that it plays key roles in maintaining active replication in both the nucleus and mitochondrion, even in the absence of exogenous damage. Human cells lacking PrimPol exhibit delayed recovery after UV-C damage and increased mutation rates, micronuclei and sister chromatin exchanges but are not sensitive to genotoxins. PrimPol is also required during mitochondrial replication, with PrimPol-deficient cells having increased mtDNA copy number but displaying a significant decrease in replication. Deletion of PrimPol in XPV cells, lacking functional polymerase Eta, causes an increase in DNA damage sensitivity and pronounced fork stalling after UV-C treatment. We show that, unlike canonical TLS polymerases, PrimPol is important for allowing active replication to proceed, even in the absence of exogenous damage, thus preventing the accumulation of excessive fork stalling and genetic mutations. Together, these findings highlight the importance of PrimPol for maintaining efficient DNA replication in unperturbed cells and its complementary roles, with Pol Eta, in damage tolerance in human cells.

Item Type: Article
Keywords: Replication; Stalling; PrimPol; Pol Eta; damage tolerance; TLS; repriming
Schools and Departments: School of Life Sciences > Sussex Centre for Genome Damage and Stability
Research Centres and Groups: Genome Damage and Stability Centre
Depositing User: Aidan Doherty
Date Deposited: 29 Jan 2019 11:56
Last Modified: 29 Jan 2019 11:56
URI: http://srodev.sussex.ac.uk/id/eprint/81543

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Project NameSussex Project NumberFunderFunder Ref
The role of a novel family of eukaryotic DNA polymerases in mitochondrial DNA replicationG0207BBSRC-BIOTECHNOLOGY & BIOLOGICAL SCIENCES RESEARCH COUNCILBB/H019723/1
Understanding the role of PrimPol in damage tolerance during genome replication in eukaryotic cellsG1621BBSRC-BIOTECHNOLOGY & BIOLOGICAL SCIENCES RESEARCH COUNCILBB/M008800/1