Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2004-4-15
pubmed:abstractText
The ATM kinase is a tumour suppressor and a key activator of genome integrity checkpoints in mammalian cells exposed to ionizing radiation (IR) and other insults that elicit DNA double-strand breaks (DSBs). In response to IR, autophosphorylation on serine 1981 causes dissociation of ATM dimers and initiates cellular ATM kinase activity. Here, we show that the kinetics and magnitude of ATM Ser1981 phosphorylation after exposure of human fibroblasts to low doses (2 Gy) of IR are altered in cells deficient in Nbs1, a substrate of ATM and a component of the MRN (Mre11-Rad50-Nbs1) complex involved in processing/repair of DSBs and ATM-dependent cell cycle checkpoints. Timely phosphorylation of both ATM Ser1981 and the ATM substrate Smc1 after IR were rescued via retrovirally mediated reconstitution of Nbs1-deficient cells by wild-type Nbs1 or mutants of Nbs1 defective in the FHA domain or nonphosphorylatable by ATM, but not by Nbs1 lacking the Mre11-interaction domain. Our data indicate that apart from its role downstream of ATM in the DNA damage checkpoint network, the MRN complex serves also as a modulator/amplifier of ATM activity. Although not absolutely required for ATM activation, the MRN nuclease complex may help reach the threshold activity of ATM necessary for optimal genome maintenance and prevention of cancer.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0950-9232
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3122-7
pubmed:dateRevised
2011-11-2
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Distinct functional domains of Nbs1 modulate the timing and magnitude of ATM activation after low doses of ionizing radiation.
pubmed:affiliation
Danish Cancer Society, Institute of Cancer Biology, Strandboulevarden 49, Copenhagen DK-2100 Denmark.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't