title: Temporally distinct translesion synthesis pathways for ultraviolet light-induced photoproducts in the mammalian genome.
abstract: Replicative polymerases (Pols) arrest at damaged DNA nucleotides, which induces ubiquitination of the DNA sliding clamp PCNA (PCNA-Ub) and DNA damage signaling. PCNA-Ub is associated with the recruitment or activation of translesion synthesis (TLS) DNA polymerases of the Y family that can bypass the lesions, thereby rescuing replication and preventing replication fork collapse and consequent formation of double-strand DNA breaks. Here, we have used gene-targeted mouse embryonic fibroblasts to perform a comprehensive study of the in vivo roles of PCNA-Ub and of the Y family TLS Pols η, ι, κ, Rev1 and the B family TLS Polζ in TLS and in the suppression of DNA damage signaling and genome instability after exposure to UV light. Our data indicate that TLS Pols ι and κ and the N-terminal BRCT domain of Rev1, that previously was implicated in the regulation of TLS, play minor roles in TLS of DNA photoproducts. PCNA-Ub is critical for an early TLS pathway that replicates both strongly helix-distorting (6-4) pyrimidine-pyrimidone ((6-4)PP) and mildly distorting cyclobutane pyrimidine dimer (CPD) photoproducts. The role of Polη is mainly restricted to early TLS of CPD photoproducts, whereas Rev1 and, in particular, Polζ are essential for the bypass of (6-4)PP photoproducts, both early and late after exposure. Thus, structurally distinct photoproducts at the mammalian genome are bypassed by different TLS Pols in temporally different, PCNA-Ub-dependent and independent fashions.
authors.affiliation: Department of Toxicogenetics, Leiden University Medical Center-LUMC, PO Box 9600, 2300 RC Leiden, The Netherlands. p.temviriyanukul@lumc.nl
authors.forename: Piya
authors.initials: P
authors.lastname: Temviriyanukul
authors.forename: Sandrine
authors.initials: S
authors.lastname: van Hees-Stuivenberg
authors.forename: Frédéric
authors.initials: F
authors.lastname: Delbos
authors.forename: Heinz
authors.initials: H
authors.lastname: Jacobs
authors.forename: Niels
authors.initials: N
authors.lastname: de Wind
authors.forename: Jacob G
authors.initials: JG
authors.lastname: Jansen
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000235:genetics / Q000528:radiation effects; D002460:Cell Line; D049109:Cell Proliferation / Q000528:radiation effects; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects*; D004260:DNA Repair; D004261:DNA Replication / Q000235:genetics / Q000528:radiation effects; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D016678:Genome / Q000235:genetics / Q000528:radiation effects*; D006657:Histones / Q000378:metabolism; D015151:Immunoblotting; D008322:Mammals / Q000235:genetics; D051379:Mice; D009154:Mutation; D010766:Phosphorylation; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics*; D025801:Ubiquitin / Q000235:genetics / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D004259:DNA-Directed DNA Polymerase; D006657:Histones; D018809:Proliferating Cell Nuclear Antigen; D025801:Ubiquitin; C425929:DNA polymerase zeta; C475961:gamma-H2AX protein, mouse