Xrcc1-dependent and Ku-dependent DNA double-strand break repair kinetics in Arabidopsis plants.

Abstract : Double-strand breakage (DSB) of DNA involves loss of information on the two strands of the DNA fibre and thus cannot be repaired by simple copying of the complementary strand which is possible with single-strand DNA damage. Homologous recombination (HR) can precisely repair DSB using another copy of the genome as template and non-homologous recombination (NHR) permits repair of DSB with little or no dependence on DNA sequence homology. In addition to the well-characterised Ku-dependent non-homologous end-joining (NHEJ) pathway, much recent attention has been focused on Ku-independent NHR. The complex interrelationships and regulation of NHR pathways remain poorly understood, even more so in the case of plants, and we present here an analysis of Ku-dependent and Ku-independent repair of DSB in Arabidopsis thaliana. We have characterised an Arabidopsis xrcc1 mutant and developed quantitative analysis of the kinetics of appearance and loss of γ-H2AX foci as a tool to measure DSB repair in dividing root tip cells of γ-irradiated plants in vivo. This approach has permitted determination of DSB repair kinetics in planta following a short pulse of γ-irradiation, establishing the existence of a Ku-independent, Xrcc1-dependent DSB repair pathway. Furthermore, our data show a role for Ku80 during the first minutes post-irradiation and that Xrcc1 also plays such a role, but only in the absence of Ku. The importance of Xrcc1 is, however, clearly visible at later times in the presence of Ku, showing that alternative end-joining plays an important role in DSB repair even in the presence of active NHEJ.
Type de document :
Article dans une revue
Plant Journal, Wiley, 2010, 64 (2), pp.280-90. 〈10.1111/j.1365-313X.2010.04331.x〉
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Contributeur : Charles White <>
Soumis le : mercredi 25 mai 2011 - 15:34:56
Dernière modification le : jeudi 11 janvier 2018 - 06:23:14

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Cyril Charbonnel, Maria Gallego, Charles White. Xrcc1-dependent and Ku-dependent DNA double-strand break repair kinetics in Arabidopsis plants.. Plant Journal, Wiley, 2010, 64 (2), pp.280-90. 〈10.1111/j.1365-313X.2010.04331.x〉. 〈inserm-00595784〉



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