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p53 binding protein 1 (53BP1) is an early participant in the cellular response to DNA doublestrand breaks (2000)
| Venue: | J Cell Biol |
| Citations: | 85 - 2 self |
BibTeX
@ARTICLE{Schultz00p53binding,
author = {Linda B. Schultz and Nabil H. Chehab and Asra Malikzay and Thanos D. Halazonetis},
title = {p53 binding protein 1 (53BP1) is an early participant in the cellular response to DNA doublestrand breaks},
journal = {J Cell Biol},
year = {2000},
pages = {151--1381}
}
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Abstract
Abstract. p53 binding protein 1 (53BP1), a protein proposed to function as a transcriptional coactivator of the p53 tumor suppressor, has BRCT domains with high homology to the Saccharomyces cerevisiae Rad9p DNA damage checkpoint protein. To examine whether 53BP1 has a role in the cellular response to DNA damage, we probed its intracellular localization by immunofluorescence. In untreated primary cells and U2OS osteosarcoma cells, 53BP1 exhibited diffuse nuclear staining; whereas, within 5–15 min after exposure to ionizing radiation (IR), 53BP1 localized at discreet nuclear foci. We propose that these foci represent sites of processing of DNA double-strand breaks (DSBs), because they were induced by IR and chemicals that cause DSBs, but not by ultraviolet light; their peak number approximated the number of DSBs induced by IR and decreased over time with kinetics that parallel the rate of DNA repair; and they colocalized with IRinduced Mre11/NBS and �-H2AX foci, which have been previously shown to localize at sites of DSBs. Formation of 53BP1 foci after irradiation was not dependent on ataxia-telangiectasia mutated (ATM), Nijmegen breakage syndrome (NBS1), or wild-type p53. Thus, the fast kinetics of 53BP1 focus formation after irradiation and the lack of dependency on ATM and NBS1 suggest that 53BP1 functions early in the cellular response to DNA DSBs. Key words: 53BP1 • p53 • DNA damage • ionizing radiation • cancer
Keyphrases
cellular response early participant dna doublestrand break diffuse nuclear staining radiation cancer dna repair focus formation key word transcriptional coactivator untreated primary cell p53 dna damage dna dsbs wild-type p53 dna double-strand break discreet nuclear focus u2os osteosarcoma cell fast kinetics focus represent site dna damage peak number h2ax focus high homology nijmegen breakage syndrome brct domain p53 tumor suppressor ultraviolet light intracellular localization irinduced mre11 nb
