Linked Life Data

6267077

Source:http://linkedlifedata.com/resource/pubmed/id/6267077

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1981-10-25
pubmed:abstractText
Three procedures were used to induced dihydrofolate reductase synthesis in quiescent cultures of methotrexate resistant mouse fibroblasts: 1) lytic infection with polyoma virus, 2) growth stimulation by replating cells at lower density in fresh cell culture medium, and 3) the addition of fresh medium to confluent cells. Following polyoma infection, an increase in the percentage of S-phase cells began at approximately 20 hours; dihydrofolate reductase synthesis also increased following a lag of 20 hours or more, and continued to increase throughout the late phase of lytic infection, reaching values nearly fivefold greater than that originally present in the quiescent cells. When quiescent cells received fresh medium (with or without replating), the percentage of cells in S phage began to increase by 10 hours and was accompanied by an increase in dihydrofolate reductase synthesis which reached a maximum by approximately 25 hours. These observations show that the initial entry of cells into S phase following mitogenic stimulation is associated with an induction of dihydrofolate reductase synthesis. Dibutyryl cyclic AMP blocked the stimulation of dihydrofolate reductase synthesis and the increase in the percentage of S-phase cells that resulted from the addition of fresh medium to confluent cells. When dibutyryl cyclic AMP was added at various times following the addition of fresh medium, the block in the induction of dihydrofolate reductase synthesis was correlated with a corresponding block in the increase in S-phase cells. These results suggest that dibutyryl cyclic AMP blocks cells at a point in G1 prior to either the induction of dihydrofolate reductase synthesis of the beginning of S phase. The relationship between the control of dihydrofolate reductase synthesis and entry into S phase suggests some form of coordinate control over these two parameters.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9541
pubmed:author
pubmed:issnType
Print
pubmed:volume
108
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
The effect of polyoma virus, serum factors, and dibutyryl cyclic AMP on dihydrofolate reductase synthesis, and the entry of quiescent cells into S phase.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't