Linked Life Data

6185479

Source:http://linkedlifedata.com/resource/pubmed/id/6185479

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1983-3-11
pubmed:abstractText
Friend erythroleukemic cells contain both type I and type II cAMP-dependent protein kinases. The amounts of type I and type II regulatory subunits (R I and R II) were established by a combination of the equilibrium binding of cyclic [3H]AMP and specific immunoprecipitation. In control cells the total specific cAMP-binding activity was 9.8 pmol/mg of cytosolic protein and the ratio of R II to R I was 1.2. After the induction of differentiation by growth in 2% dimethyl sulfoxide, the total cAMP-binding capacity doubled, but larger and opposing changes in R II and R I levels were observed. The concentration of R II tripled (to 16.6 pmol/mg) while R I content (1.5 pmol/mg) declined to one-third of the control cell level, resulting in an R II:R I value of 11.1. Treatment of Friend cells with 0.5 mM 8-bromoadenosine 3':5'-monophosphate (8-Br-cAMP) and 0.2 mM methylisobutyl xanthine for 2 days did not stimulate cell differentiation. however, the cAMP-binding capacity nearly doubled and the cells accumulated a high level of R II while R I declined. This resulted in a distribution of R subunits closely resembling that of differentiated cells. Cyclic AMP-stimulated histone kinase activity increased in proportion to cAMP-binding activity during differentiation; no such increase was seen following 8-Br-cAMP treatment. Fractionation of cytosolic extracts by DEAE-cellulose chromatography revealed that both R I and R II were fully associated with the catalytic subunit (C) of protein kinase before and after differentiation. In extracts of 8-Br-cAMP-treated cells all of R I and 40 to 60% of R II were not associated with C. Free R II isolated from these cells was indistinguishable from RII present in holoenzyme. Thus, erythroid differentiation of Friend cells results in a coordinate accumulation of R II and C subunits as well as a decline in R I content. In contrast, chronic exposure to 8-Br-cAMP elicits similar changes in R subunit levels but disrupts the coordinate regulation of R and C content.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
258
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
777-84
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Regulation of cAMP-dependent protein kinase subunit levels in Friend erythroleukemic cells. Effects of differentiation and treatment with 8-Br-cAMP and methylisobutyl xanthine.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.