Linked Life Data

1650726

Source:http://linkedlifedata.com/resource/pubmed/id/1650726

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-9-9
pubmed:abstractText
We have investigated the increase of phosphorylated proteins upon activation of surf clam (Spisula solidissima) oocytes, by measuring the cumulative incorporation of 32P in proteins and by performing an SDS-PAGE and autoradiographic analysis of 32P-labeled proteins, from oocytes initially radiolabeled with 32P-orthophosphate. The phosphorylation inhibitor 6-dimethylaminopurine (6-DMAP) inhibits both germinal vesicle breakdown (GVBD) and the normal increase in phosphorylated proteins observed upon activation by KCl, in a reversible and dose-dependent manner. Using different artificial seawaters (normal, Ca(2+)-free, Na(+)-free), we observed that the increase of phosphorylated proteins, upon K+ stimulation, occurs only when GVBD is allowed to proceed along with an increased Ca2+ influx, in normal or Na(+)-free seawater. Stimulation of oocytes by ammonia, which directly raises intracellular pH (pHi) but does not trigger GVBD, is without effect on the level or pattern of phosphorylated proteins. The link between the Ca2+ influx and the level of phosphorylated proteins was further investigated using conditions altering the duration or the level of Ca2+ influx upon K+ stimulation. In all conditions tested, both GVBD and the level of phosphorylated proteins were similarly affected by alterations of the Ca2+ influx, indicating that these processes are tightly coupled one with another. Upon activation of oocytes, six major proteins of estimated molecular weights of 31, 41, 48, 56, 80 and 86 kDa undergo an increased phosphorylation that is reversibly sensitive to 6-DMAP. Our results suggest that increased protein phosphorylation, sensitive to 6-DMAP, is necessary for GVBD and that it is indirectly linked to the increased Ca2+ influx that stands as an upstream trigger for activation, while an elevated pHi alone has no effect on these processes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0012-1606
pubmed:author
pubmed:issnType
Print
pubmed:volume
146
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
473-82
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Protein phosphorylation during activation of surf clam oocytes.
pubmed:affiliation
Département d'Océanographie, Université du Québec à Rimouski, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't