title: PrimPol-deficient cells exhibit a pronounced G2 checkpoint response following UV damage.
abstract: PrimPol is a recently identified member of the archaeo-eukaryote primase (AEP) family of primase-polymerases. It has been shown that this mitochondrial and nuclear localized enzyme plays roles in the maintenance of both unperturbed replication fork progression and in the bypass of lesions after DNA damage. Here, we utilized an avian (DT40) knockout cell line to further study the consequences of loss of PrimPol (PrimPol(-/-)) on the downstream maintenance of cells after UV damage. We report that PrimPol(-/-) cells are more sensitive to UV-C irradiation in colony survival assays than Pol η-deficient cells. Although this increased UV sensitivity is not evident in cell viability assays, we show that this discrepancy is due to an enhanced checkpoint arrest after UV-C damage in the absence of PrimPol. PrimPol(-/-) arrested cells become stalled in G2, where they are protected from UV-induced cell death. Despite lacking an enzyme required for the bypass and maintenance of replication fork progression in the presence of UV damage, we show that PrimPol(-/-) cells actually have an advantage in the presence of a Chk1 inhibitor due to their slow progression through S-phase.
authors.affiliation: a Genome Damage and Stability Centre, School of Life Sciences, University of Sussex , Brighton , UK.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Bailey
authors.affiliation: a Genome Damage and Stability Centre, School of Life Sciences, University of Sussex , Brighton , UK.|b Present address: Department of Oncology-Pathology, Cancer Center Karolinska, Karolinska Institutet , Stockholm , Sweden.
authors.forename: Julie
authors.initials: J
authors.lastname: Bianchi
authors.affiliation: a Genome Damage and Stability Centre, School of Life Sciences, University of Sussex , Brighton , UK.
authors.forename: Nadia
authors.initials: N
authors.lastname: Hégarat
authors.affiliation: a Genome Damage and Stability Centre, School of Life Sciences, University of Sussex , Brighton , UK.
authors.forename: Helfrid
authors.initials: H
authors.lastname: Hochegger
authors.affiliation: a Genome Damage and Stability Centre, School of Life Sciences, University of Sussex , Brighton , UK.
authors.forename: Aidan J
authors.initials: AJ
authors.lastname: Doherty
mesh_terms: D000818:Animals; D016923:Cell Death; D002460:Cell Line; D049109:Cell Proliferation; D002470:Cell Survival / Q000528:radiation effects; D000071877:Checkpoint Kinase 1; D002645:Chickens; D004249:DNA Damage; D019915:DNA Primase / Q000235:genetics / Q000502:physiology*; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000502:physiology*; D016195:G2 Phase / Q000528:radiation effects; D059565:G2 Phase Cell Cycle Checkpoints; D055786:Gene Knockout Techniques; D008938:Mitosis / Q000528:radiation effects; D014466:Ultraviolet Rays; D048051:p38 Mitogen-Activated Protein Kinases / Q000502:physiology
chemical_list: D000071877:Checkpoint Kinase 1; D048051:p38 Mitogen-Activated Protein Kinases; D019915:DNA Primase; D004259:DNA-Directed DNA Polymerase
keywords: Chk1; DT40; PrimPol; TLS; UV; cell cycle; checkpoint; polymerase; primase; replication