title: ATR kinase activation in G1 phase facilitates the repair of ionizing radiation-induced DNA damage.
abstract: The kinase ATR is activated by RPA-coated single-stranded DNA generated at aberrant replicative structures and resected double strand breaks. While many hundred candidate ATR substrates have been identified, the essential role of ATR in the replicative stress response has impeded the study of ATR kinase-dependent signalling. Using recently developed selective drugs, we show that ATR inhibition has a significantly more potent effect than ATM inhibition on ionizing radiation (IR)-mediated cell killing. Transient ATR inhibition for a short interval after IR has long-term consequences that include an accumulation of RPA foci and a total abrogation of Chk1 S345 phosphorylation. We show that ATR kinase activity in G1 phase cells is important for survival after IR and that ATR colocalizes with RPA in the absence of detectable RPA S4/8 phosphorylation. Our data reveal that, unexpectedly, ATR kinase inhibitors may be more potent cellular radiosensitizers than ATM kinase inhibitors, and that this is associated with a novel role for ATR in G1 phase cells.
authors.affiliation: Department of Radiation Oncology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA, Department of Cell Biology and Physiology, Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA, Department of Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, PA, USA and Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
authors.forename: Armin M
authors.initials: AM
authors.lastname: Gamper
authors.forename: Reza
authors.initials: R
authors.lastname: Rofougaran
authors.forename: Simon C
authors.initials: SC
authors.lastname: Watkins
authors.forename: Joel S
authors.initials: JS
authors.lastname: Greenberger
authors.forename: Jan H
authors.initials: JH
authors.lastname: Beumer
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Bakkenist
mesh_terms: D064007:Ataxia Telangiectasia Mutated Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D002460:Cell Line; D000071877:Checkpoint Kinase 1; D004249:DNA Damage; D004260:DNA Repair; D016193:G1 Phase / Q000235:genetics* / Q000528:radiation effects; D006801:Humans; D011494:Protein Kinases / Q000378:metabolism; D011836:Radiation Tolerance; D011839:Radiation, Ionizing; D051716:Replication Protein A / Q000032:analysis; D015398:Signal Transduction
chemical_list: D051716:Replication Protein A; D011494:Protein Kinases; C576597:ATR protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1
references.citation: J Clin Invest. 2010 Jul;120(7):2528-36
references.pmid: 20577054
references.citation: Cancer Res. 2004 Dec 15;64(24):9152-9
references.pmid: 15604286
references.citation: Oncogene. 2012 Mar 1;31(9):1086-94
references.pmid: 21765472
references.citation: Nat Cell Biol. 2006 Jan;8(1):37-45
references.pmid: 16327781
references.citation: Pulm Pharmacol Ther. 1999;12(5):291-302
references.pmid: 10545285
references.citation: Genes Dev. 2000 Jun 15;14(12):1439-47
references.pmid: 10859163
references.citation: Mol Biol Cell. 2010 Mar 15;21(6):926-35
references.pmid: 20110345
references.citation: J Biol Chem. 2006 Sep 22;281(38):27855-61
references.pmid: 16864589
references.citation: EMBO J. 1998 Jan 2;17(1):159-69
references.pmid: 9427750
references.citation: J Proteome Res. 2012 Oct 5;11(10):4983-91
references.pmid: 22909323
references.citation: Proc Natl Acad Sci U S A. 1980 Dec;77(12):7315-7
references.pmid: 6938978
references.citation: J Biol Chem. 2000 Feb 25;275(8):5600-5
references.pmid: 10681541
references.citation: Sci Signal. 2010 Jun 01;3(124):ra44
references.pmid: 20516478
references.citation: Nucleic Acids Res. 2012 Jan;40(2):477-86
references.pmid: 21937510
references.citation: Biochemistry. 2012 Aug 7;51(31):6246-59
references.pmid: 22788932
references.citation: Trends Cell Biol. 2010 Jul;20(7):402-9
references.pmid: 20444606
references.citation: Genes Dev. 2000 Feb 15;14(4):397-402
references.pmid: 10691732
references.citation: Science. 2000 Dec 22;290(5500):2309-12
references.pmid: 11125146
references.citation: Curr Biol. 2003 Jun 17;13(12):1047-51
references.pmid: 12814551
references.citation: Science. 2003 Jun 6;300(5625):1542-8
references.pmid: 12791985
references.citation: EMBO J. 2010 Nov 3;29(21):3723-32
references.pmid: 20871591
references.citation: Nat Struct Mol Biol. 2011 Jun;18(6):721-7
references.pmid: 21552262
references.citation: Genes Dev. 2000 Jun 15;14(12):1448-59
references.pmid: 10859164
references.citation: Cell. 2006 Mar 10;124(5):943-55
references.pmid: 16530042
references.citation: Adv Cancer Res. 2010;108:73-112
references.pmid: 21034966
references.citation: PLoS Biol. 2003 Nov;1(2):E33
references.pmid: 14624239
references.citation: Genes Dev. 2008 Jun 1;22(11):1478-89
references.pmid: 18519640
references.citation: J Med Chem. 2011 Apr 14;54(7):2320-30
references.pmid: 21413798
references.citation: Cell Cycle. 2008 May 1;7(9):1277-84
references.pmid: 18418045
references.citation: Oncogene. 1994 Mar;9(3):707-18
references.pmid: 8108113
references.citation: Genes Dev. 2007 Jun 15;21(12):1472-7
references.pmid: 17575048
references.citation: Mol Cell. 2010 Oct 22;40(2):179-204
references.pmid: 20965415
references.citation: EMBO J. 2006 Mar 8;25(5):1126-36
references.pmid: 16482215
references.citation: Cell Cycle. 2010 Oct 15;9(20):4052-7
references.pmid: 20953138
references.citation: J Biol Chem. 2009 Apr 3;284(14):9558-65
references.pmid: 19202191
references.citation: Science. 2001 Nov 23;294(5547):1713-6
references.pmid: 11721054
references.citation: Proc Natl Acad Sci U S A. 1998 Jun 23;95(13):7445-50
references.pmid: 9636169
references.citation: J Cell Biol. 2012 Jun 25;197(7):869-76
references.pmid: 22733999
references.citation: Radiother Oncol. 2013 Feb;106(2):260-5
references.pmid: 23199651
references.citation: Curr Biol. 2000 Apr 20;10(8):479-82
references.pmid: 10801416
references.citation: Cell. 2010 Apr 16;141(2):243-54
references.pmid: 20362325