Cell cycle-regulated centers of DNA double-strand break repair.
In eukaryotes, homologous recombination is an important pathway for the repair of DNA double-strand breaks. We have studied this process in living cells in the yeast Saccharomyces cerevisiae using Rad52 as a cell biological marker. In response to DNA damage, Rad52 redistributes itself and forms foci specifically during S phase. We have shown previously that Rad52 foci are centers of DNA repair where multiple DNA double-strand breaks colocalize. Here we report a correlation between the timing of Rad52 focus formation and modification of the Rad52 protein. In addition, we show that the two ends of a double-strand break are held tightly together in the majority of cells. Interestingly, in a small but significant fraction of the S phase cells, the two ends of a break separate suggesting that mechanisms exist to reassociate and align these ends for proper DNA repair.
Lisby
Michael
M
Department of Genetics and Development, Columbia University, College of Physicians and Surgeons, New York, New York 10032-2704, USA.
Antúnez de Mayolo
Adriana
A
Mortensen
Uffe H
UH
Rothstein
Rodney
R
D002453:Cell Cycle / Q000235:genetics / Q000502:physiology*; D004249:DNA Damage / Q000235:genetics / Q000502:physiology*; D004260:DNA Repair / Q000235:genetics / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D051721:Rad52 DNA Repair and Recombination Protein; D011995:Recombination, Genetic / Q000502:physiology*; D016196:S Phase / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins
D004268:DNA-Binding Proteins; C497197:RAD52 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins