Linked Life Data

2569465

Source:http://linkedlifedata.com/resource/pubmed/id/2569465

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
23
pubmed:dateCreated
1989-9-11
pubmed:abstractText
The proliferating cell nuclear antigen (PCNA), also known as cyclin and DNA polymerase delta auxiliary factor, is present in reduced amounts in nongrowing cells and is synthesized at a greater rate in the S phase of growing cells. The recently discovered involvement of PCNA in DNA replication suggested that this pattern of expression functions to regulate DNA synthesis. We have investigated this possibility further by examining the synthesis, stability, and accumulation of PCNA in HeLa cells fractionated by centrifugal elutriation into nearly synchronous populations of cells at various positions in the cell cycle. In these fractionated cells we found that there is an increase in the rate of PCNA synthesis with a peak in early S phase of the cell cycle, but the magnitude of the increase is only 2-3-fold. This change reflects similar changes in the amount of PCNA mRNA. The fluctuating synthesis of PCNA maintains this protein at a roughly constant proportion of the total cell protein, although the amount doubles/cell in the cell cycle. Consistent with this observation, the stability of PCNA does not differ significantly from that of total cellular protein in synchronized HeLa cells. We also observed that a maximum of one-third of the total PCNA is tightly associated with the nucleus, presumably in replication complexes, at the peak of S phase. We conclude that the cyclic synthesis of PCNA in cycling HeLa cells maintains PCNA in excess of the amount involved directly in DNA replication and the amount of the protein neither fluctuates significantly with the cell cycle nor is limiting for DNA synthesis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
264
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13856-64
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Regulation of proliferating cell nuclear antigen during the cell cycle.
pubmed:affiliation
Cold Spring Harbor Laboratory, New York 11724.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.