title: Increase in dNTP pool size during the DNA damage response plays a key role in spontaneous and induced-mutagenesis in Escherichia coli.
abstract: Exposure of Escherichia coli to UV light increases expression of NrdAB, the major ribonucleotide reductase leading to a moderate increase in dNTP levels. The role of elevated dNTP levels during translesion synthesis (TLS) across specific replication-blocking lesions was investigated. Here we show that although the specialized DNA polymerase PolV is necessary for replication across UV-lesions, such as cyclobutane pyrimidine dimers or pyrimidine(6-4)pyrimidone photoproduct, Pol V per se is not sufficient. Indeed, efficient TLS additionally requires elevated dNTP levels. Similarly, for the bypass of an N-2-acetylaminofluorene-guanine adduct that requires Pol II instead of PolV, efficient TLS is only observed under conditions of high dNTP levels. We suggest that increased dNTP levels transiently modify the activity balance of Pol III (i.e., increasing the polymerase and reducing the proofreading functions). Indeed, we show that the stimulation of TLS by elevated dNTP levels can be mimicked by genetic inactivation of the proofreading function (mutD5 allele). We also show that spontaneous mutagenesis increases proportionally to dNTP pool levels, thus defining a unique spontaneous mutator phenotype. The so-called "dNTP mutator" phenotype does not depend upon any of the specialized DNA polymerases, and is thus likely to reflect an increase in Pol III's own replication errors because of the modified activity balance of Pol III. As up-regulation of the dNTP pool size represents a common physiological response to DNA damage, the present model is likely to represent a general and unique paradigm for TLS pathways in many organisms.
authors.affiliation: Genome Instability and Carcinogenesis,  Centre National de la Recherche Scientifique, Unité Propre de Recherche 3081, 13402 Marseille,  France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Gon
authors.forename: Rita
authors.initials: R
authors.lastname: Napolitano
authors.forename: Walter
authors.initials: W
authors.lastname: Rocha
authors.forename: Stéphane
authors.initials: S
authors.lastname: Coulon
authors.forename: Robert P
authors.initials: RP
authors.lastname: Fuchs
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004249:DNA Damage / Q000235:genetics*; D004258:DNA Polymerase III / Q000378:metabolism*; D004260:DNA Repair / Q000235:genetics*; D003854:Deoxyribonucleotides / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000528:radiation effects; D005697:Galactosides; D007211:Indoles; D008957:Models, Genetic; D016296:Mutagenesis / Q000235:genetics; D014466:Ultraviolet Rays
chemical_list: D003854:Deoxyribonucleotides; D005697:Galactosides; D007211:Indoles; D004258:DNA Polymerase III; C044888:5-bromo-4-chloro-3-indolyl beta-galactoside
references.citation: J Biol Chem. 2004 Apr 9;279(15):14496-501
references.pmid: 14752109
references.citation: Proc Natl Acad Sci U S A. 1992 Feb 15;89(4):1310-4
references.pmid: 1741385
references.citation: J Biol Chem. 2001 May 25;276(21):18031-7
references.pmid: 11278973
references.citation: J Bacteriol. 1983 Dec;156(3):1192-7
references.pmid: 6196349
references.citation: Proc Natl Acad Sci U S A. 2000 Jun 6;97(12):6640-5
references.pmid: 10829079
references.citation: J Bacteriol. 2002 May;184(10):2674-81
references.pmid: 11976296
references.citation: DNA Repair (Amst). 2008 May 3;7(5):801-10
references.pmid: 18400565
references.citation: Mol Gen Genet. 1990 Feb;220(3):400-8
references.pmid: 2187154
references.citation: Mol Biol Cell. 1992 Oct;3(10):1095-105
references.pmid: 1384814
references.citation: J Mol Biol. 2004 Aug 6;341(2):405-17
references.pmid: 15276832
references.citation: Proc Natl Acad Sci U S A. 1998 Oct 27;95(22):13114-9
references.pmid: 9789050
references.citation: J Biol Chem. 1999 Feb 5;274(6):3705-10
references.pmid: 9920922
references.citation: Proc Natl Acad Sci U S A. 1999 Aug 3;96(16):8919-24
references.pmid: 10430871
references.citation: J Bacteriol. 1997 Dec;179(23):7435-45
references.pmid: 9393709
references.citation: DNA Repair (Amst). 2007 Jul 1;6(7):1032-41
references.pmid: 17403618
references.citation: Antioxid Redox Signal. 2006 May-Jun;8(5-6):773-80
references.pmid: 16771669
references.citation: Oncogene. 2007 Aug 9;26(36):5184-93
references.pmid: 17310982
references.citation: Proc Natl Acad Sci U S A. 1989 Jun;86(11):4147-51
references.pmid: 2657743
references.citation: Genetics. 2002 Sep;162(1):5-13
references.pmid: 12242219
references.citation: EMBO J. 2000 Nov 15;19(22):6259-65
references.pmid: 11080171
references.citation: Proc Natl Acad Sci U S A. 2007 Jan 23;104(4):1183-8
references.pmid: 17227840
references.citation: Genes Dev. 2010 Feb 15;24(4):333-8
references.pmid: 20159953
references.citation: Genes Cells. 2002 Apr;7(4):385-99
references.pmid: 11952835
references.citation: Nucleic Acids Res. 2008 Oct;36(17):5660-7
references.pmid: 18772226
references.citation: J Mol Biol. 2007 Sep 28;372(4):883-893
references.pmid: 17707403
references.citation: Curr Genet. 2007 Apr;51(4):221-31
references.pmid: 17287963
references.citation: J Biol Chem. 2006 Mar 24;281(12):7834-41
references.pmid: 16436374
references.citation: J Biol Chem. 1998 Sep 4;273(36):23575-84
references.pmid: 9722597
references.citation: Genetics. 2001 May;158(1):41-64
references.pmid: 11333217
references.citation: Mutat Res. 1995 Jan;336(1):39-48
references.pmid: 7528894
references.citation: Mol Gen Genet. 1982;185(1):43-50
references.pmid: 6211591
references.citation: EMBO J. 2010 Jun 16;29(12):2048-58
references.pmid: 20453833
references.citation: DNA Repair (Amst). 2002 Feb 28;1(2):159-67
references.pmid: 12509262
references.citation: Proc Natl Acad Sci U S A. 1984 Dec;81(23):7539-43
references.pmid: 6390441
references.citation: Proc Natl Acad Sci U S A. 2001 Jul 17;98(15):8566-71
references.pmid: 11447256
references.citation: Cell. 2003 Feb 7;112(3):391-401
references.pmid: 12581528
references.citation: Mutat Res. 1985 Jun-Jul;150(1-2):133-9
references.pmid: 4000157
references.citation: EMBO J. 2004 Oct 27;23(21):4342-52
references.pmid: 15470496
references.citation: J Mol Biol. 2005 Sep 23;352(3):501-9
references.pmid: 16111701
references.citation: J Mol Biol. 1995 Dec 1;254(3):337-41
references.pmid: 7490752
references.citation: J Biol Chem. 1998 Dec 18;273(51):34098-104
references.pmid: 9852067
references.citation: Adv Protein Chem. 2004;69:229-64
references.pmid: 15588845
references.citation: J Bacteriol. 2006 Nov;188(22):7977-80
references.pmid: 16980447
references.citation: Annu Rev Biochem. 2006;75:681-706
references.pmid: 16756507
references.citation: Nucleic Acids Res. 2011 Mar;39(4):1360-71
references.pmid: 20961955
references.citation: EMBO J. 2006 Mar 8;25(5):1137-47
references.pmid: 16482221
references.citation: Genes Dev. 1990 May;4(5):740-51
references.pmid: 2199320
references.citation: J Biol Chem. 1996 Oct 25;271(43):26582-7
references.pmid: 8900130
references.citation: DNA Repair (Amst). 2005 Dec 8;4(12):1450-6
references.pmid: 16207537
references.citation: DNA Repair (Amst). 2002 Sep 4;1(9):703-8
references.pmid: 12509274
references.citation: Proc Natl Acad Sci U S A. 2009 Sep 1;106(35):14825-30
references.pmid: 19706415
references.citation: Mol Microbiol. 1996 Feb;19(4):777-90
references.pmid: 8820648
references.citation: J Mol Biol. 1999 Nov 26;294(2):299-306
references.pmid: 10610759
references.citation: Proc Natl Acad Sci U S A. 2008 Jul 22;105(29):10197-202
references.pmid: 18621712
references.citation: J Bacteriol. 1985 Aug;163(2):677-87
references.pmid: 3160686
references.citation: Mol Microbiol. 2002 Jan;43(2):487-95
references.pmid: 11985724
references.citation: Proc Natl Acad Sci U S A. 1978 Jul;75(7):3037-41
references.pmid: 356043
references.citation: Mutat Res. 1994 Aug;318(1):1-64
references.pmid: 7519315
references.citation: J Mol Biol. 1999 Apr 23;288(1):191-9
references.pmid: 10329136
references.citation: Nature. 2000 Apr 27;404(6781):1014-8
references.pmid: 10801133