Linked Life Data

10375689

Source:http://linkedlifedata.com/resource/pubmed/id/10375689

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-8-13
pubmed:abstractText
The effect of external Ca2+ ([Ca2+]e) on the incorporation of [32P] into total protein, cytoskeletal proteins and the heat shock protein HSP27, was studied in primary cultures of astrocytes from the rat hippocampus. Zero [Ca2+]e increased total 32P-incorporation into astrocyte protein and when this was normalized to 100%, incorporation was significantly increased into glial fibrillary acidic protein (GFAP), vimentin (VIM) and HSP27. The difference in total 32P-incorporation between zero [Ca2+]e and 1 mM [Ca2+]e was reversed by incubation of the cells with the protein phosphatase inhibitor okadaic acid in the range 1-10 nM; higher concentrations of okadaic acid (50-100 nM) further increased total 32P-incorporation. In zero [Ca2+]e the non-specific channel blocker Co2+ (1 mM) decreased total 32P-incorporation by approximately 30%. The results were compared with a previous study [S.T. Wofchuk, R. Rodnight, Age-dependent changes in the regulation by external calcium ions of the phosphorylation of glial fibrillary acidic protein in slices of rat hippocampus, Dev. Brain Res. 85 (1995) 181-186] in which it was shown that in immature hippocampal slices zero [Ca2+]e compared with 1 mM [Ca2+]e increased 32P-incorporation into GFAP without changing total incorporation. The difference between the results for total 32P-incorporation obtained in cultured astrocytes and immature brain tissue was found to be related to the concentration of [Ca2+]e in the medium since in slices concentrations of [Ca2+]e higher than 1 mM progressively decreased total incorporation. The difference may reflect a higher Ca2+-permeability of the plasma membrane in cultured astrocytes and/or to the complex structure of the slice tissue. In two-dimensional electrophoresis HSP27, in contrast to GFAP and VIM, was separated into 3 immunodetectable isoforms only two of which were normally phosphorylated. After labelling in the presence of okadaic acid both immunodetectable and phosphorylated HSP27 focussed as a single polypeptide. Phorbol dibutyrate (1 microM) and zero [Ca2+]e stimulated the phosphorylation of both isoforms, but in the case of zero [Ca2+]e the effect on the more acidic isoform was proportionally greater.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-8993
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Published by Elsevier Science B.V.
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
833
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
142-9
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:10375689-Age Factors, pubmed-meshheading:10375689-Animals, pubmed-meshheading:10375689-Animals, Newborn, pubmed-meshheading:10375689-Astrocytes, pubmed-meshheading:10375689-Biological Transport, pubmed-meshheading:10375689-Calcium, pubmed-meshheading:10375689-Cells, Cultured, pubmed-meshheading:10375689-Cobalt, pubmed-meshheading:10375689-Cytoskeleton, pubmed-meshheading:10375689-Enzyme Inhibitors, pubmed-meshheading:10375689-Glial Fibrillary Acidic Protein, pubmed-meshheading:10375689-Heat-Shock Proteins, pubmed-meshheading:10375689-Hippocampus, pubmed-meshheading:10375689-Okadaic Acid, pubmed-meshheading:10375689-Organ Culture Techniques, pubmed-meshheading:10375689-Phosphates, pubmed-meshheading:10375689-Phosphoprotein Phosphatases, pubmed-meshheading:10375689-Phosphorus Radioisotopes, pubmed-meshheading:10375689-Phosphorylation, pubmed-meshheading:10375689-Rats, pubmed-meshheading:10375689-Rats, Wistar, pubmed-meshheading:10375689-Vimentin
pubmed:year
1999
pubmed:articleTitle
Regulation of protein phosphorylation in astrocyte cultures by external calcium ions: specific effects on the phosphorylation of glial fibrillary acidic protein (GFAP), vimentin and heat shock protein 27 (HSP27).
pubmed:affiliation
Departamento de Bioquímica, UFRGS, Instituto de Ciências Básicas da Saúde, Rua Ramiro Barcelos 2600-Anexo, 90.035.003, Porto Alegre, RS, Brazil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't