Linked Life Data

18635963

Source:http://linkedlifedata.com/resource/pubmed/id/18635963

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
2008-7-25
pubmed:abstractText
Progression through the mammalian cell division cycle is regulated by the sequential activation of cyclin-dependent kinases, CDKs, at specific phases of the cell cycle. Cyclin A-CDK2 and cyclin A-CDK1 phosphorylate nuclear substrates during S and G(2) phases, respectfully. However, the DNA helicase complex, MCM2-7, is loaded onto the origin of replications in G(1), prior to the normally scheduled induction of cyclin A. It has previously been shown that cyclin A-CDKs phosphorylate MCM2 and MCM4 in vitro, thereby diminishing helicase activity. Thus, in this study we hypothesize that, in vivo, cyclin A-CDK activity during G(1) would result in an inhibition of progression into the S phase. To test this, we establish an in vivo method of inducing cyclin A-CDK activity in G(1) phase and observe that activation of cyclin A-CDK, but not cyclin E-CDK complexes, inhibit DNA synthesis without affecting other G(1) events such as cyclin D synthesis, E2F activation and cdc6 loading onto chromatin. We further report that the mechanism of this S phase inhibition occurs, at least in part, through impaired loading of MCM onto chromatin, presumably due to decreased levels of cdt1 and premature phosphorylation of MCM by cyclin A-CDK. In addition to providing in vivo confirmation of in vitro predictions regarding cyclin A-CDK phosphorylation of the MCM complex, our results provide insight into the cellular effects of unscheduled cyclin A-CDK activity in mammalian cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1551-4005
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2179-88
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Cyclin A-CDK activity during G1 phase impairs MCM chromatin loading and inhibits DNA synthesis in mammalian cells.
pubmed:affiliation
Department of Pharmacological Sciences at Saint Louis University, St. Louis, Missouri 63104, USA.
pubmed:publicationType
Journal Article