Complementation of defective translesion synthesis and UV light sensitivity in xeroderma pigmentosum variant cells by human and mouse DNA polymerase eta

Nucleic Acids Res. 2000 Jul 1;28(13):2473-80. doi: 10.1093/nar/28.13.2473.


Defects in the human gene XPV result in the variant form of the genetic disease xeroderma pigmentosum (XP-V). XPV encodes DNA polymerase eta, a novel DNA polymerase that belongs to the UmuC/DinB/Rad30 superfamily. This polymerase catalyzes the efficient and accurate translesion synthesis of DNA past cis-syn cyclobutane di-thymine lesions. In this report we present the cDNA sequence and expression profiles of the mouse XPV gene and demonstrate its ability to complement defective DNA synthesis in XP-V cells. The mouse XPV protein shares 80.3% amino acid identity and 86.9% similarity with the human XPV protein. The recombinant mouse XPV protein corrected the inability of XP-V cell extracts to carry out DNA replication, by bypassing thymine dimers on template DNA. Transfection of the mouse or human XPV cDNA into human XP-V cells corrected UV sensitivity. Northern blot analysis revealed that the mouse XPV gene is expressed ubiquitously, but at a higher level in testis, liver, skin and thymus compared to other tissues. Although the mouse XPV gene was not induced by UV irradiation, its expression was elevated approximately 4-fold during cell proliferation. These results suggest that DNA polymerase eta plays a role in DNA replication, though the enzyme is not essential for viability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Division
  • Cell Line
  • Cell Survival / radiation effects
  • Cloning, Molecular
  • DNA Polymerase iota
  • DNA Replication / genetics
  • DNA-Directed DNA Polymerase / chemistry
  • DNA-Directed DNA Polymerase / genetics*
  • DNA-Directed DNA Polymerase / metabolism*
  • Gene Expression Profiling
  • Gene Expression Regulation, Enzymologic / radiation effects
  • Genetic Complementation Test*
  • Genetic Variation / genetics
  • Humans
  • Mice
  • Molecular Sequence Data
  • Mutation / genetics*
  • Pyrimidine Dimers / genetics
  • Pyrimidine Dimers / metabolism
  • Pyrimidine Dimers / radiation effects
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Radiation Tolerance* / genetics
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transfection
  • Ultraviolet Rays
  • Xeroderma Pigmentosum / enzymology*
  • Xeroderma Pigmentosum / genetics
  • Xeroderma Pigmentosum / metabolism
  • Xeroderma Pigmentosum / pathology


  • Pyrimidine Dimers
  • RNA, Messenger
  • DNA-Directed DNA Polymerase
  • Rad30 protein
  • DNA Polymerase iota

Associated data

  • GENBANK/AB027218
  • GENBANK/AB037184