Linked Life Data

240845

Source:http://linkedlifedata.com/resource/pubmed/id/240845

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1975-12-23
pubmed:abstractText
Purified nuclei of HeLa S3 cells contain two DNA-dependent DNA polymerases that have distinct physical and enzymatic properties. We have investigated the variations in their activity during the cell cycle of a synchronized culture. Cells were synchronized by a double thymidine block, harvested at various phases of the cycle, and the two DNA polymerases were purified partially by DEAE-cellulose and phosphocellulose chromatography. The activity of DNA polymerase I (low molecular weight, N-ethylmaleimide-insensitive) remains essentially constant throughout the cycle. The activity of DNA polymerase II (high molecular weight, N-ethylmaleimide-sensitive), however, increases during G1 to mid-S and declines, 7- to 10-fold between late-S and G2. Addition of cycloheximide (60 mug/ml) to cultures 12 hours after the release from thymidine block abolishes the rise in the activity of DNA polymerase II. Cycloheximide also reduced the activity of DNA polymerase I by 60%. Addition of hydroxyurea (1mM) at 1 hour after release has no effect on the activity of either enzyme. We conclude that in HeLa cells, DNA polymerase I and II are distinct enzymes, that DNA polymerase II probably functions in DNA replication and is probably induced in response to stimuli for DNA biosynthesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
250
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7951-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1975
pubmed:articleTitle
Nuclear DNA polymerases and the HeLa cell cycle.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.