Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2002-1-9
pubmed:abstractText
cdc2 is inactivated before mitosis by phosphorylation at its inhibitory sites, Thr-14 and Tyr-15. Irradiation prevents HeLa cells from completing the G(2)-M transition, and they arrest in G(2). Whereas phosphorylation at both of these sites occurs during the G(2) arrest, the individual role of each site in the G(2) delay has not previously been investigated. We have shown that the radiation-induced G(2) delay is preserved in wild-type or cdc2-AY-transfected cells (which retain Tyr-15); this delay is abolished in cdc2-TF- or cdc2-AF-transfected cells (which lack Tyr-15). Thus Tyr-15, but not Thr-14, appears to be essential for development of a G(2) delay after radiation. Abolishment of the G(2) delay by mutation at Tyr-15 resulted in the accumulation of cells with condensed chromatin and disrupted lamin B, suggesting that these cells may be blocked at a second G(2)-M checkpoint in early mitosis (i.e., prophase). These data suggest (a) that the two inhibitory phosphorylation sites have distinct functions and that Tyr-15 phosphorylation, in particular, has a key role in the radiation-induced G(2) delay, and (b) that a second G(2)-M checkpoint exists in early mitosis and that activation of this checkpoint by radiation prevents cells that enter mitosis from progressing further.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
62
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
241-50
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Abolishment of the Tyr-15 inhibitory phosphorylation site on cdc2 reduces the radiation-induced G(2) delay, revealing a potential checkpoint in early mitosis.
pubmed:affiliation
Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.