TU Darmstadt / ULB / TUbiblio

The role of homologous recombination in radiation-induced double-strand break repair.

Jeggo, Penny A. and Geuting, Verena and Löbrich, Markus (2011):
The role of homologous recombination in radiation-induced double-strand break repair.
In: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology, pp. 7-12, 101, (1), ISSN 1879-0887,
[Article]

Abstract

DNA double-strand breaks (DSBs) represent the most biologically significant lesions induced by ionizing radiation (IR). HR is the predominant pathway for repairing one-ended DSBs arising in S-phase when the replication fork encounters single-stranded breaks or base damages. Here, we discuss recent findings that two-ended DSBs directly induced by X- or γ-rays in late S- or G2-phase are repaired predominantly by NHEJ, with HR only repairing a sub-fraction of such DSBs. This sub-fraction represents DSBs which localize to heterochromatic DNA regions and, which in control cells, are repaired with slow kinetics over many hours post irradiation. The observation that defined DSB populations are repaired by either NHEJ or HR suggests an assignment of specific tasks for each of the two processes. Furthermore, heavy ion induced complex DSBs, which are in general more slowly repaired than X- or γ-ray induced breaks, are nearly always repaired by HR independent of chromatin localization suggesting that the speed of repair is an important factor determining the DSB repair pathway usage. Finally, NHEJ and HR can, under certain conditions, also compensate for each other such that DSBs normally repaired by one pathway can undergo repair by the other if genetic failures necessitate the pathway switch.

Item Type: Article
Erschienen: 2011
Creators: Jeggo, Penny A. and Geuting, Verena and Löbrich, Markus
Title: The role of homologous recombination in radiation-induced double-strand break repair.
Language: English
Abstract:

DNA double-strand breaks (DSBs) represent the most biologically significant lesions induced by ionizing radiation (IR). HR is the predominant pathway for repairing one-ended DSBs arising in S-phase when the replication fork encounters single-stranded breaks or base damages. Here, we discuss recent findings that two-ended DSBs directly induced by X- or γ-rays in late S- or G2-phase are repaired predominantly by NHEJ, with HR only repairing a sub-fraction of such DSBs. This sub-fraction represents DSBs which localize to heterochromatic DNA regions and, which in control cells, are repaired with slow kinetics over many hours post irradiation. The observation that defined DSB populations are repaired by either NHEJ or HR suggests an assignment of specific tasks for each of the two processes. Furthermore, heavy ion induced complex DSBs, which are in general more slowly repaired than X- or γ-ray induced breaks, are nearly always repaired by HR independent of chromatin localization suggesting that the speed of repair is an important factor determining the DSB repair pathway usage. Finally, NHEJ and HR can, under certain conditions, also compensate for each other such that DSBs normally repaired by one pathway can undergo repair by the other if genetic failures necessitate the pathway switch.

Journal or Publication Title: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
Volume: 101
Number: 1
Divisions: 10 Department of Biology > Radiation Biology and DNA Repair
?? fb10_zoologie ??
10 Department of Biology
Date Deposited: 12 Jan 2012 13:35
Export:
Suche nach Titel in: TUfind oder in Google

Optionen (nur für Redakteure)

View Item View Item