Linked Life Data

6329288

Source:http://linkedlifedata.com/resource/pubmed/id/6329288

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1984-8-3
pubmed:abstractText
The activities of nuclear envelope-associated protein phosphokinase and protein phosphatase were determined in nuclear ghosts from liver and oviduct of quails. The protein kinase was found to be inhibited by poly(A) by 75%. During the kinase reaction proteins with molecular weights of 106 000 and 64 000 were phosphorylated. The phosphoprotein phosphatase from liver was stimulated to 190% by poly(A), whereas only a slight enhancing effect by this polymer was determined with the oviduct enzyme (to 125%). Comparative determinations of the nuclear ghost-associated enzyme activities revealed the following values (in nmol Pi/min per 10(8) ghosts); oviduct: phosphokinase, 0.015; phosphatase, 0.004 and nucleoside triphosphatase, 39.4; and liver: phosphokinase, 0.044; phosphatase, 0.012 and nucleoside triphosphatase, 11.7. These data indicate that phosphorylation/dephosphorylation proceeds independently of the nucleoside triphosphatase cycle. This assumption is supported by analytical results revealing that no marked dephosphorylation occurs after poly(A) binding to the nuclear envelope. Moreover, stoichiometrical data showed a nearly 1:1 molar ratio between ATP-binding and phosphorylation of nuclear envelope protein. From these findings a new model for the nucleoside triphosphatase-mediated poly(A)(+)mRNA efflux from nuclei is deducted, proposing phosphokinase and phosphatase only to modulate the affinity of the 'carrier structure' for poly(A) (+)mRNA, but not to constitute the nucleoside triphosphatase.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
773
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
308-16
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
The role of protein phosphokinase and protein phosphatase during the nuclear envelope nucleoside triphosphatase reaction.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't