Linked Life Data

6328534

Source:http://linkedlifedata.com/resource/pubmed/id/6328534

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1984-7-20
pubmed:abstractText
Polyamines are known to have a role in cell proliferation, differentiation, and protein synthesis. During pregnancy, major changes in polyamine levels occur in maternal serum, amniotic fluid, and placental tissue. Polyamine-activated phosphorylation has recently been proposed as a mechanism by which polyamines may regulate metabolic processes in target tissues. Polyamine-activated protein phosphorylation has not been studied in placenta. Homogenate membrane and cytosol fractions from human placenta were subjected to an endogenous protein phosphorylation assay using [gamma-32P]ATP in the presence and absence of the polyamines, spermine and spermidine, and the diamine, putrescine. Protein phosphorylation was assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. When compared to basal levels, spermine (10(-3) M) significantly (P less than 0.001) stimulated 32P incorporation into phosphoproteins having molecular weights of 55,000 and 105,000. At this concentration spermidine and putrescine failed to stimulate phosphorylation. Half-maximal 32P incorporation was observed with 3.7 +/- 1.25 X 10(-4) M spermine. Polylysine enhanced the phosphorylation of phosphoproteins of the same molecular weight as those enhanced by spermine. Heparin and high Mg2+ inhibited spermine-induced phosphorylation. cAMP and Ca2+ did not stimulate phosphorylation of the spermine-dependent phosphoproteins. Spermine, however, acted as an antagonist for cAMP-dependent phosphorylation of a Mr 45,000 phosphoprotein.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0037-9727
pubmed:author
pubmed:issnType
Print
pubmed:volume
176
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
313-21
pubmed:dateRevised
2007-11-2
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Spermine-enhanced protein phosphorylation in human placenta.
pubmed:publicationType
Journal Article, Comparative Study