A broad requirement for TLS polymerases η and κ, and interacting sumoylation and nuclear pore proteins, in lesion bypass during C. elegans embryogenesis

PLoS Genet. 2012 Jun;8(6):e1002800. doi: 10.1371/journal.pgen.1002800. Epub 2012 Jun 28.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans Proteins / metabolism
  • Caenorhabditis elegans* / embryology
  • Caenorhabditis elegans* / genetics
  • Cisplatin / pharmacology
  • DNA Damage* / drug effects
  • DNA Damage* / genetics
  • DNA Damage* / radiation effects
  • DNA Repair / genetics*
  • DNA-Directed DNA Polymerase* / genetics
  • DNA-Directed DNA Polymerase* / metabolism
  • Embryonic Development / genetics
  • Gamma Rays
  • Gene Knockout Techniques
  • Homologous Recombination / drug effects
  • Homologous Recombination / genetics
  • Homologous Recombination / radiation effects
  • Methyl Methanesulfonate / pharmacology
  • Nuclear Pore / genetics
  • Porins / genetics
  • Porins / metabolism
  • Radiation-Protective Agents / metabolism
  • Small Ubiquitin-Related Modifier Proteins / genetics
  • Small Ubiquitin-Related Modifier Proteins / metabolism
  • Sumoylation / genetics
  • Ultraviolet Rays


  • Caenorhabditis elegans Proteins
  • Porins
  • Radiation-Protective Agents
  • Small Ubiquitin-Related Modifier Proteins
  • Methyl Methanesulfonate
  • DNA-Directed DNA Polymerase
  • POLH-1 protein, C elegans
  • POLK-1 protein, C elegans
  • Cisplatin