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ID 14204
file
creator
Tomita, Kazunori
Matsuura, Akira
Caspari, Thomas
Carr, Antony M.
Akamatsu, Yufuko
Iwasaki, Hiroshi
Mizuno, Ken-ichi
Ohta, Kunihiro
Uritani, Masahiro
Ushimaru, Takashi
Yoshinaga, Koichi
NDC
Biology
abstract
The Mre11-Rad50-Nbs1(Xrs2) complex and the Ku70-Ku80 heterodimer are thought to compete with each other for binding to DNA ends. To investigate the mechanism underlying this competition, we analyzed both DNA damage sensitivity and telomere overhangs in Schizosaccharomyces pombe rad50-d, rad50-d pku70-d, rad50-d exo1-d, and pku70-d rad50-d exo1-d cells. We found that rad50 exo1 double mutants are more methyl methanesulfonate (MMS) sensitive than the respective single mutants. The MMS sensitivity of rad50-d cells was suppressed by concomitant deletion of pku70+. However, the MMS sensitivity of the rad50 exo1 double mutant was not suppressed by the deletion of pku70+. The G-rich overhang at telomere ends in taz1-d cells disappeared upon deletion of rad50+, but the overhang reappeared following concomitant deletion of pku70+. Our data suggest that the Rad50 complex can process DSB ends and telomere ends in the presence of the Ku heterodimer. However, the Ku heterodimer inhibits processing of DSB ends and telomere ends by alternative nucleases in the absence of the Rad50-Rad32 protein complex. While we have identified Exo1 as the alternative nuclease targeting DNA break sites, the identity of the nuclease acting on the telomere ends remains elusive.
journal title
Molecular and cellular biology
volume
Volume 23
start page
5186
end page
5197
date of issued
2003-08
publisher
American Society for Microbiology
issn
0270-7306
publisher doi
pubmed id
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
author
rights
Copyright (c) American Society for Microbiology
relation is version of URL
http://dx.doi.org/10.1128/MCB.23.15.5186-5197.2003
department
Graduate School of Advanced Sciences of Matter