A centrosome-autonomous signal that involves centriole disengagement permits centrosome duplication in G2 phase after DNA damage.
dc.contributor.author | Inanç, Burcu | |
dc.contributor.author | Dodson, Helen | |
dc.contributor.author | Morrison, Ciaran G | |
dc.date.accessioned | 2011-03-21T16:21:57Z | |
dc.date.available | 2011-03-21T16:21:57Z | |
dc.date.issued | 2010-11-15 | |
dc.identifier.citation | A centrosome-autonomous signal that involves centriole disengagement permits centrosome duplication in G2 phase after DNA damage. 2010, 21 (22):3866-77 Mol. Biol. Cell | en |
dc.identifier.issn | 1939-4586 | |
dc.identifier.pmid | 20861312 | |
dc.identifier.doi | 10.1091/mbc.E10-02-0124 | |
dc.identifier.uri | http://hdl.handle.net/10147/125266 | |
dc.description.abstract | DNA damage can induce centrosome overduplication in a manner that requires G2-to-M checkpoint function, suggesting that genotoxic stress can decouple the centrosome and chromosome cycles. How this happens is unclear. Using live-cell imaging of cells that express fluorescently tagged NEDD1/GCP-WD and proliferating cell nuclear antigen, we found that ionizing radiation (IR)-induced centrosome amplification can occur outside S phase. Analysis of synchronized populations showed that significantly more centrosome amplification occurred after irradiation of G2-enriched populations compared with G1-enriched or asynchronous cells, consistent with G2 phase centrosome amplification. Irradiated and control populations of G2 cells were then fused to test whether centrosome overduplication is allowed through a diffusible stimulatory signal, or the loss of a duplication-inhibiting signal. Irradiated G2/irradiated G2 cell fusions showed significantly higher centrosome amplification levels than irradiated G2/unirradiated G2 fusions. Chicken-human cell fusions demonstrated that centrosome amplification was limited to the irradiated partner. Our finding that only the irradiated centrosome can duplicate supports a model where a centrosome-autonomous inhibitory signal is lost upon irradiation of G2 cells. We observed centriole disengagement after irradiation. Although overexpression of dominant-negative securin did not affect IR-induced centrosome amplification, Plk1 inhibition reduced radiation-induced amplification. Together, our data support centriole disengagement as a licensing signal for DNA damage-induced centrosome amplification. | |
dc.language.iso | en | en |
dc.subject.mesh | Animals | |
dc.subject.mesh | Calcium-Binding Proteins | |
dc.subject.mesh | Cell Cycle | |
dc.subject.mesh | Cell Cycle Proteins | |
dc.subject.mesh | Cell Line, Tumor | |
dc.subject.mesh | Centrioles | |
dc.subject.mesh | Centrosome | |
dc.subject.mesh | DNA Damage | |
dc.subject.mesh | G2 Phase | |
dc.subject.mesh | Humans | |
dc.subject.mesh | Immunoblotting | |
dc.subject.mesh | Luminescent Proteins | |
dc.subject.mesh | Microscopy, Fluorescence | |
dc.subject.mesh | Microtubule-Associated Proteins | |
dc.subject.mesh | Proliferating Cell Nuclear Antigen | |
dc.subject.mesh | S Phase | |
dc.subject.mesh | Signal Transduction | |
dc.subject.mesh | Time Factors | |
dc.title | A centrosome-autonomous signal that involves centriole disengagement permits centrosome duplication in G2 phase after DNA damage. | en |
dc.type | Article | en |
dc.contributor.department | Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland. | en |
dc.identifier.journal | Molecular biology of the cell | en |
html.description.abstract | DNA damage can induce centrosome overduplication in a manner that requires G2-to-M checkpoint function, suggesting that genotoxic stress can decouple the centrosome and chromosome cycles. How this happens is unclear. Using live-cell imaging of cells that express fluorescently tagged NEDD1/GCP-WD and proliferating cell nuclear antigen, we found that ionizing radiation (IR)-induced centrosome amplification can occur outside S phase. Analysis of synchronized populations showed that significantly more centrosome amplification occurred after irradiation of G2-enriched populations compared with G1-enriched or asynchronous cells, consistent with G2 phase centrosome amplification. Irradiated and control populations of G2 cells were then fused to test whether centrosome overduplication is allowed through a diffusible stimulatory signal, or the loss of a duplication-inhibiting signal. Irradiated G2/irradiated G2 cell fusions showed significantly higher centrosome amplification levels than irradiated G2/unirradiated G2 fusions. Chicken-human cell fusions demonstrated that centrosome amplification was limited to the irradiated partner. Our finding that only the irradiated centrosome can duplicate supports a model where a centrosome-autonomous inhibitory signal is lost upon irradiation of G2 cells. We observed centriole disengagement after irradiation. Although overexpression of dominant-negative securin did not affect IR-induced centrosome amplification, Plk1 inhibition reduced radiation-induced amplification. Together, our data support centriole disengagement as a licensing signal for DNA damage-induced centrosome amplification. |