MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Akyüz, N.
Right arrow Articles by Wiesmüller, L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Akyüz, N.
Right arrow Articles by Wiesmüller, L.
Molecular and Cellular Biology, September 2002, p. 6306-6317, Vol. 22, No. 17
0270-7306/02/$04.00+0     DOI: 10.1128/MCB.22.17.6306-6317.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

DNA Substrate Dependence of p53-Mediated Regulation of Double-Strand Break Repair

Nuray Akyüz,1,2 Gisa S. Boehden,1,2 Silke Süsse,1,2 Andreas Rimek,2 Ute Preuss,3 Karl-Heinz Scheidtmann,3 and Lisa Wiesmüller1,2*

Universitätsfrauenklinik, D-89075 Ulm,1 Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie an der Universität Hamburg, D-20251 Hamburg,2 Abteilung Molekulargenetik, Institut für Genetik, Universität Bonn, D-53117 Bonn, Germany3

Received 24 January 2002/ Returned for modification 27 February 2002/ Accepted 4 June 2002

DNA double-strand breaks (DSBs) arise spontaneously after the conversion of DNA adducts or single-strand breaks by DNA repair or replication and can be introduced experimentally by expression of specific endonucleases. Correct repair of DSBs is central to the maintenance of genomic integrity in mammalian cells, since errors give rise to translocations, deletions, duplications, and expansions, which accelerate the multistep process of tumor progression. For p53 direct regulatory roles in homologous recombination (HR) and in non-homologous end joining (NHEJ) were postulated. To systematically analyze the involvement of p53 in DSB repair, we generated a fluorescence-based assay system with a series of episomal and chromosomally integrated substrates for I-SceI meganuclease-triggered repair. Our data indicate that human wild-type p53, produced either stably or transiently in a p53-negative background, inhibits HR between substrates for conservative HR (cHR) and for gene deletions. NHEJ via microhomologies flanking the I-SceI cleavage site was also downregulated after p53 expression. Interestingly, the p53-dependent downregulation of homology-directed repair was maximal during cHR between sequences with short homologies. Inhibition was minimal during recombination between substrates that support reporter gene reconstitution by HR and NHEJ. p53 with a hotspot mutation at codon 281, 273, 248, 175, or 143 was severely defective in regulating DSB repair (frequencies elevated up to 26-fold). For the transcriptional transactivation-inactive variant p53(138V) a defect became apparent with short homologies only. These results suggest that p53 plays a role in restraining DNA exchange between imperfectly homologous sequences and thereby in suppressing tumorigenic genome rearrangements.


* Corresponding author. Mailing address: Universitätsfrauenklinik, Prittwitzstrasse 43, 89075 Ulm, Germany. Phone: 49-731-50027640. Fax: 49-731-50026674. E-mail: Lisa.Wiesmueller{at}medizin.uni-ulm.de.


Molecular and Cellular Biology, September 2002, p. 6306-6317, Vol. 22, No. 17
0022-538X/02/$04.00+0     DOI: 10.1128/MCB.22.17.6306-6317.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.




This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 2002 by the American Society for Microbiology. All rights reserved.