1. Academic Validation
  2. The POLD3 subunit of DNA polymerase δ can promote translesion synthesis independently of DNA polymerase ζ

The POLD3 subunit of DNA polymerase δ can promote translesion synthesis independently of DNA polymerase ζ

  • Nucleic Acids Res. 2015 Feb 18;43(3):1671-83. doi: 10.1093/nar/gkv023.
Kouji Hirota 1 Kazunori Yoshikiyo 2 Guillaume Guilbaud 3 Toshiki Tsurimoto 4 Junko Murai 5 Masataka Tsuda 2 Lara G Phillips 3 Takeo Narita 2 Kana Nishihara 2 Kaori Kobayashi 6 Kouich Yamada 7 Jun Nakamura 8 Yves Pommier 4 Alan Lehmann 9 Julian E Sale 10 Shunichi Takeda 11
Affiliations

Affiliations

  • 1 Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto 606-8501, Japan Department of Chemistry, GraduateSchool of Science and Engineering, Tokyo Metropolitan University, Minami-Osawa, Hachioji- shi, Tokyo 192-0397, Japan.
  • 2 Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto 606-8501, Japan.
  • 3 Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK.
  • 4 Department of Biology, School of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
  • 5 Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto 606-8501, Japan Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
  • 6 Department of Chemistry, GraduateSchool of Science and Engineering, Tokyo Metropolitan University, Minami-Osawa, Hachioji- shi, Tokyo 192-0397, Japan.
  • 7 Division of Genetic Biochemistry, National Institute of Health and Nutrition, Tokyo 162-8636, Japan.
  • 8 Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC 27599, USA.
  • 9 Genome Damage and Stability Centre, University of Sussex, Falmer, Brighton BN1 9RQ, UK.
  • 10 Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK jes@mrc-lmb.cam.ac.uk.
  • 11 Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshidakonoe, Sakyo-ku, Kyoto 606-8501, Japan stakeda@rg.med.kyoto-u.ac.jp.
Abstract

The replicative DNA Polymerase Polδ consists of a catalytic subunit POLD1/p125 and three regulatory subunits POLD2/p50, POLD3/p66 and POLD4/p12. The ortholog of POLD3 in Saccharomyces cerevisiae, Pol32, is required for a significant proportion of spontaneous and UV-induced mutagenesis through its additional role in translesion synthesis (TLS) as a subunit of DNA Polymerase ζ. Remarkably, chicken DT40 B lymphocytes deficient in POLD3 are viable and able to replicate undamaged genomic DNA with normal kinetics. Like its counterpart in yeast, POLD3 is required for fully effective TLS, its loss resulting in hypersensitivity to a variety of DNA damaging agents, a diminished ability to maintain replication fork progression after UV irradiation and a significant decrease in abasic site-induced mutagenesis in the immunoglobulin loci. However, these defects appear to be largely independent of Polζ, suggesting that POLD3 makes a significant contribution to TLS independently of Polζ in DT40 cells. Indeed, combining polη, polζ and pold3 mutations results in synthetic lethality. Additionally, we show in vitro that POLD3 promotes extension beyond an abasic by the Polδ holoenzyme suggesting that while POLD3 is not required for normal replication, it may help Polδ to complete abasic site bypass independently of canonical TLS polymerases.

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