Linked Life Data

16935576

Source:http://linkedlifedata.com/resource/pubmed/id/16935576

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
2006-9-18
pubmed:abstractText
DNA polymerase alpha (pol-alpha) is a heterotetrameric enzyme (p180-p68-p58-p48 in mouse) that is essential for the initiation of chain elongation during DNA replication. The catalytic (p180) and p68 subunits of pol-alpha are phosphorylated by Cdk-cyclin complexes, with p68 being hyperphosphorylated by cyclin-dependent kinases in G(2) phase of the cell cycle. The activity of Cdk2-cyclin A increases during late S phase and peaks in G(2) phase. We have now examined the role of p68 in the interaction between the catalytic subunit of pol-alpha and hyperphosphorylated retinoblastoma protein (ppRb) and in the stimulation of the polymerase activity of pol-alpha by ppRb. With the use of recombinant proteins, we found that nonphosphorylated p68 inhibited the stimulation of pol-alpha activity by ppRb, suggesting that p68 might impede the association of ppRb with p180. Phosphorylation of p68 by Cdk2-cyclin A greatly reduced its inhibitory effect. Immunofluorescence analysis also revealed that ppRb localized at sites of DNA replication specifically in late S phase. These results suggest that Cdk-cyclin A can phosphorylate pol-alpha which may result in a conformational change in pol-alpha facilitating its interaction with and activation by ppRb.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:volume
1764
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1447-53
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Role of the second-largest subunit of DNA polymerase alpha in the interaction between the catalytic subunit and hyperphosphorylated retinoblastoma protein in late S phase.
pubmed:affiliation
Department of Biology, Faculty of Science, Tokyo University of Science, RIKADAI, Kagurazaka 1-3, Tokyo 162-8601, Japan. takemura@rs.kagu.tus.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't