title: DNA polymerases beta and lambda mediate overlapping and independent roles in base excision repair in mouse embryonic fibroblasts.
abstract: Base excision repair (BER) is a DNA repair pathway designed to correct small base lesions in genomic DNA. While DNA polymerase beta (pol beta) is known to be the main polymerase in the BER pathway, various studies have implicated other DNA polymerases in back-up roles. One such polymerase, DNA polymerase lambda (pol lambda), was shown to be important in BER of oxidative DNA damage. To further explore roles of the X-family DNA polymerases lambda and beta in BER, we prepared a mouse embryonic fibroblast cell line with deletions in the genes for both pol beta and pol lambda. Neutral red viability assays demonstrated that pol lambda and pol beta double null cells were hypersensitive to alkylating and oxidizing DNA damaging agents. In vitro BER assays revealed a modest contribution of pol lambda to single-nucleotide BER of base lesions. Additionally, using co-immunoprecipitation experiments with purified enzymes and whole cell extracts, we found that both pol lambda and pol beta interact with the upstream DNA glycosylases for repair of alkylated and oxidized DNA bases. Such interactions could be important in coordinating roles of these polymerases during BER.
authors.affiliation: Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, United States of America.
authors.forename: Elena K
authors.initials: EK
authors.lastname: Braithwaite
authors.forename: Padmini S
authors.initials: PS
authors.lastname: Kedar
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Stumpo
authors.forename: Barbara
authors.initials: B
authors.lastname: Bertocci
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Freedman
authors.forename: Leona D
authors.initials: LD
authors.lastname: Samson
authors.forename: Samuel H
authors.initials: SH
authors.lastname: Wilson
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival; D004249:DNA Damage; D045647:DNA Glycosylases / Q000378:metabolism; D019951:DNA Polymerase beta / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair; D004622:Embryo, Mammalian; D005347:Fibroblasts / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D055786:Gene Knockout Techniques; D006801:Humans; D051379:Mice
chemical_list: C415367:DNA polymerase beta2; D019951:DNA Polymerase beta; C021565:3-methyladenine-DNA glycosylase; D045647:DNA Glycosylases; C485990:Ogg1 protein, mouse
references.citation: J Exp Med. 2003 Aug 18;198(4):635-43
references.pmid: 12925679
references.citation: Mol Cell. 2004 Jul 23;15(2):209-20
references.pmid: 15260972
references.citation: J Biol Chem. 1995 Jul 7;270(27):16402-8
references.pmid: 7608211
references.citation: Genes Cells. 2005 Jul;10(7):705-15
references.pmid: 15966901
references.citation: DNA Repair (Amst). 2007 Jun 1;6(6):869-75
references.pmid: 17363341
references.citation: DNA Repair (Amst). 2007 Jan 4;6(1):3-7
references.pmid: 16979388
references.citation: J Biol Chem. 2002 Aug 23;277(34):31115-23
references.pmid: 12063248
references.citation: J Biol Chem. 2003 Oct 10;278(41):39951-9
references.pmid: 12882965
references.citation: DNA Repair (Amst). 2008 Jun 1;7(6):830-3
references.pmid: 18434259
references.citation: J Biol Chem. 2005 May 6;280(18):18469-75
references.pmid: 15749700
references.citation: Methods Enzymol. 1995;262:98-107
references.pmid: 8594388
references.citation: Nat Protoc. 2008;3(7):1125-31
references.pmid: 18600217
references.citation: J Immunol. 2002 Apr 15;168(8):3702-6
references.pmid: 11937519
references.citation: FEBS J. 2006 Apr;273(8):1620-9
references.pmid: 16623699
references.citation: J Biol Chem. 2000 Sep 15;275(37):28607-17
references.pmid: 10884383
references.citation: DNA Repair (Amst). 2002 Apr 29;1(4):317-33
references.pmid: 12509250
references.citation: Biochemistry. 2003 Oct 28;42(42):12418-29
references.pmid: 14567703
references.citation: J Biol Chem. 2005 Sep 9;280(36):31641-7
references.pmid: 16002405
references.citation: Nucleic Acids Res. 2000 Aug 15;28(16):3040-6
references.pmid: 10931918
references.citation: Nature. 2007 May 31;447(7144):606-8
references.pmid: 17507928
references.citation: Nucleic Acids Res. 2007;35(15):5173-81
references.pmid: 17666409
references.citation: Nature. 1996 Jan 11;379(6561):183-6
references.pmid: 8538772