Two-polymerase mechanisms dictate error-free and error-prone translesion DNA synthesis in mammals

EMBO J. 2009 Feb 18;28(4):383-93. doi: 10.1038/emboj.2008.281. Epub 2009 Jan 15.

Abstract

DNA replication across blocking lesions occurs by translesion DNA synthesis (TLS), involving a multitude of mutagenic DNA polymerases that operate to protect the mammalian genome. Using a quantitative TLS assay, we identified three main classes of TLS in human cells: two rapid and error-free, and the third slow and error-prone. A single gene, REV3L, encoding the catalytic subunit of DNA polymerase zeta (pol zeta), was found to have a pivotal role in TLS, being involved in TLS across all lesions examined, except for a TT cyclobutane dimer. Genetic epistasis siRNA analysis indicated that discrete two-polymerase combinations with pol zeta dictate error-prone or error-free TLS across the same lesion. These results highlight the central role of pol zeta in both error-prone and error-free TLS in mammalian cells, and show that bypass of a single lesion may involve at least three different DNA polymerases, operating in different two-polymerase combinations.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line, Tumor
  • DNA / chemistry*
  • DNA / metabolism*
  • DNA Damage*
  • DNA Replication*
  • DNA-Directed DNA Polymerase / chemistry
  • DNA-Directed DNA Polymerase / metabolism*
  • Dimerization
  • Epistasis, Genetic
  • Humans
  • Kinetics
  • Mice
  • Mutagenesis
  • Pyrimidine Dimers / chemistry
  • RNA, Small Interfering / metabolism
  • Xeroderma Pigmentosum Group A Protein / metabolism

Substances

  • Pyrimidine Dimers
  • RNA, Small Interfering
  • XPA protein, human
  • Xeroderma Pigmentosum Group A Protein
  • DNA
  • DNA-Directed DNA Polymerase