title: Centrosome amplification induced by DNA damage occurs during a prolonged G2 phase and involves ATM.
abstract: Centrosomes are the principal microtubule organising centres in somatic cells. Abnormal centrosome number is common in tumours and occurs after gamma-irradiation and in cells with mutations in DNA repair genes. To investigate how DNA damage causes centrosome amplification, we examined cells that conditionally lack the Rad51 recombinase and thereby incur high levels of spontaneous DNA damage. Rad51-deficient cells arrested in G2 phase and formed supernumerary functional centrosomes, as assessed by light and serial section electron microscopy. This centrosome amplification occurred without an additional DNA replication round and was not the result of cytokinesis failure. G2-to-M checkpoint over-ride by caffeine or wortmannin treatment strongly reduced DNA damage-induced centrosome amplification. Radiation-induced centrosome amplification was potentiated by Rad54 disruption. Gene targeting of ATM reduced, but did not abrogate, centrosome amplification induced by DNA damage in both the Rad51 and Rad54 knockout models, demonstrating ATM-dependent and -independent components of DNA damage-inducible G2-phase centrosome amplification. Our data suggest DNA damage-induced centrosome amplification as a mechanism for ensuring death of cells that evade the DNA damage or spindle assembly checkpoints.
authors.affiliation: Department of Biochemistry and NCBES, National University of Ireland-Galway, Galway, Ireland.
authors.forename: Helen
authors.initials: H
authors.lastname: Dodson
authors.forename: Emer
authors.initials: E
authors.lastname: Bourke
authors.forename: Liam J
authors.initials: LJ
authors.lastname: Jeffers
authors.forename: Paola
authors.initials: P
authors.lastname: Vagnarelli
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Sonoda
authors.forename: Shunichi
authors.initials: S
authors.lastname: Takeda
authors.forename: William C
authors.initials: WC
authors.lastname: Earnshaw
authors.forename: Andreas
authors.initials: A
authors.lastname: Merdes
authors.forename: Ciaran
authors.initials: C
authors.lastname: Morrison
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D030161:Avian Proteins; D002110:Caffeine / Q000494:pharmacology; D018797:Cell Cycle Proteins / Q000235:genetics / Q000502:physiology*; D002455:Cell Division; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D018385:Centrosome / Q000502:physiology*; D002645:Chickens; D043171:Chromosomal Instability; D048749:Cytokinesis; D004249:DNA Damage; D004265:DNA Helicases; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D016195:G2 Phase; D005784:Gene Amplification; D018390:Gene Targeting; D006801:Humans; D047569:Laser Scanning Cytometry; D051379:Mice; D008938:Mitosis; D009183:Mycotoxins / Q000494:pharmacology; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000502:physiology*; D051135:Rad51 Recombinase; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000502:physiology*; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D030161:Avian Proteins; D018797:Cell Cycle Proteins; D000697:Central Nervous System Stimulants; D004268:DNA-Binding Proteins; D009183:Mycotoxins; D009687:Nuclear Proteins; D047428:Protein Kinase Inhibitors; D025521:Tumor Suppressor Proteins; D002110:Caffeine; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C576325:Atm protein, mouse; D017346:Protein Serine-Threonine Kinases; C495150:RAD51 protein, Gallus gallus; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; C495154:Rad51 protein, mouse; D004265:DNA Helicases; C103532:RAD54L protein, human; D000077191:Wortmannin