ATR and ATM play both distinct and additive roles in response to ionizing radiation
Article first published online: 17 NOV 2006
The Plant Journal
Volume 48, Issue 6, pages 947–961, December 2006
How to Cite
Culligan, K. M., Robertson, C. E., Foreman, J., Doerner, P. and Britt, A. B. (2006), ATR and ATM play both distinct and additive roles in response to ionizing radiation. The Plant Journal, 48: 947–961. doi: 10.1111/j.1365-313X.2006.02931.x
- Issue published online: 21 NOV 2006
- Article first published online: 17 NOV 2006
- Received 29 June 2006; revised 22 August 2006; accepted 24 August 2006.
- double-strand break;
- cell-cycle arrest;
The ATR and ATM protein kinases are known to be involved in a wide variety of responses to DNA damage. The Arabidopsis thaliana genome includes both ATR and ATM orthologs, and plants with null alleles of these genes are viable. Arabidopsis atr and atm mutants display hypersensitivity to γ-irradiation. To further characterize the roles of ATM and ATR in response to ionizing radiation, we performed a short-term global transcription analysis in wild-type and mutant lines. We found that hundreds of genes are upregulated in response to γ-irradiation, and that the induction of virtually all of these genes is dependent on ATM, but not ATR. The transcript of CYCB1;1 is unique among the cyclin transcripts in being rapidly and powerfully upregulated in response to ionizing radiation, while other G2-associated transcripts are suppressed. We found that both ATM and ATR contribute to the induction of a CYCB1;1:GUS fusion by IR, but only ATR is required for the persistence of this response. We propose that this upregulation of CYCB1;1 does not reflect the accumulation of cells in G2, but instead reflects a still unknown role for this cyclin in DNA damage response.