title: A broad requirement for TLS polymerases η and κ, and interacting sumoylation and nuclear pore proteins, in lesion bypass during C. elegans embryogenesis.
abstract: Translesion synthesis (TLS) polymerases are specialized DNA polymerases capable of inserting nucleotides opposite DNA lesions that escape removal by dedicated DNA repair pathways. TLS polymerases allow cells to complete DNA replication in the presence of damage, thereby preventing checkpoint activation, genome instability, and cell death. Here, we characterize functional knockouts for polh-1 and polk-1, encoding the Caenorhabditis elegans homologs of the Y-family TLS polymerases η and κ. POLH-1 acts at many different DNA lesions as it protects cells against a wide range of DNA damaging agents, including UV, γ-irradiation, cisplatin, and methyl methane sulphonate (MMS). POLK-1 acts specifically but redundantly with POLH-1 in protection against methylation damage. Importantly, both polymerases play a prominent role early in embryonic development to allow fast replication of damaged genomes. Contrary to observations in mammalian cells, we show that neither POLH-1 nor POLK-1 is required for homologous recombination (HR) repair of DNA double-strand breaks. A genome-wide RNAi screen for genes that protect the C. elegans genome against MMS-induced DNA damage identified novel components in DNA damage bypass in the early embryo. Our data suggest SUMO-mediated regulation of both POLH-1 and POLK-1, and point towards a previously unrecognized role of the nuclear pore in regulating TLS.
authors: Department of Toxicogenetics, Leiden University Medical Center, Leiden, The Netherlands.
authors: Sophie F
authors: SF
authors: Roerink
authors: Wouter
authors: W
authors: Koole
authors: L Carine
authors: LC
authors: Stapel
authors: Ron J
authors: RJ
authors: Romeijn
authors: Marcel
authors: M
authors: Tijsterman
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism; D002945:Cisplatin / Q000494:pharmacology; D004249:DNA Damage / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D004260:DNA Repair / Q000235:genetics*; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism; D047108:Embryonic Development / Q000235:genetics; D005720:Gamma Rays; D055786:Gene Knockout Techniques; D059765:Homologous Recombination / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D022022:Nuclear Pore / Q000235:genetics; D018272:Porins / Q000235:genetics / Q000378:metabolism; D011837:Radiation-Protective Agents / Q000378:metabolism; D025841:Small Ubiquitin-Related Modifier Proteins / Q000235:genetics / Q000378:metabolism; D058207:Sumoylation / Q000235:genetics; D014466:Ultraviolet Rays; D000099270:Y-Family DNA Polymerases
chemical_list: D029742:Caenorhabditis elegans Proteins; D002945:Cisplatin; D004259:DNA-Directed DNA Polymerase; D008741:Methyl Methanesulfonate; D018272:Porins; D011837:Radiation-Protective Agents; D025841:Small Ubiquitin-Related Modifier Proteins; C575162:POLH-1 protein, C elegans; D000099270:Y-Family DNA Polymerases; C575163:POLK-1 protein, C elegans