title: Complementation of defective translesion synthesis and UV light sensitivity in xeroderma pigmentosum variant cells by human and mouse DNA polymerase eta.
abstract: 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.
authors.affiliation: Institute for Molecular and Cellular Biology, Osaka University and CREST, Japan Science and Technology Corporation, Yamada-oka, Japan,
authors.forename: A
authors.initials: A
authors.lastname: Yamada
authors.forename: C
authors.initials: C
authors.lastname: Masutani
authors.forename: S
authors.initials: S
authors.lastname: Iwai
authors.forename: F
authors.initials: F
authors.lastname: Hanaoka
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002455:Cell Division; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D003001:Cloning, Molecular; D004261:DNA Replication / Q000235:genetics; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic / Q000528:radiation effects; D005816:Genetic Complementation Test; D014644:Genetic Variation / Q000235:genetics; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D011740:Pyrimidine Dimers / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011836:Radiation Tolerance / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014162:Transfection; D014466:Ultraviolet Rays; D014983:Xeroderma Pigmentosum / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D000094769:DNA Polymerase iota; D000099270:Y-Family DNA Polymerases
chemical_list: D004259:DNA-Directed DNA Polymerase; D011740:Pyrimidine Dimers; D012333:RNA, Messenger; D000094769:DNA Polymerase iota; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases