Linked Life Data

1406704

Source:http://linkedlifedata.com/resource/pubmed/id/1406704

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1992-11-6
pubmed:abstractText
Previous observations that extracellular calcium (Ca2+) enhanced PRL mRNA levels posttranscriptionally in GH3 rat pituitary tumor cells were made using double-stranded transcription probes. The effects of Ca2+ and the Ca2+ ionophore, ionomycin, on PRL gene expression in GH3 and 235-1 cells were investigated using site- and strand-specific probes. Treatment of GH3 and 235-1 cells with 0.5 mM Ca2+ in serum-free medium specifically increased PRL mRNA levels by severalfold. In 235-1 but not GH3 cells PRL gene transcription was comparably induced by Ca2+. Use of single-stranded 5' and 3' probes revealed no antisense transcription, nor any Ca2+ effect on transcriptional elongation. Treatment with Ca2+ plus ionomycin inhibited PRL mRNA levels and gene transcription in both cell lines. Although their PRL gene transcription rates are similar, several basic differences were noted between the cell lines. The 235-1 cells exhibit a different profile of nuclear PRL pre-RNAs than GH3 cells. Also, mRNA levels for a Ca(2+)-regulated gene (GRP78) did not change in Ca(2+)-treated GH3 cells but decreased in Ca(2+)-treated 235-1 cells. Ionomycin treatment increased GRP78 mRNA levels in both cell lines. Thus, addition of extracellular Ca2+ appears to affect [Ca2+]i in 235-1 but not GH3 cells, while ionomycin affects [Ca2+]i in both cell lines. These data suggest that changing [Ca2+]i modulates PRL gene transcription. The comparative data suggest that posttranscriptional PRL regulation is Ca(2+)-regulated in GH3 cells, but is constitutive in 235-1 cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0888-8809
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1268-76
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Effects of calcium and calcium ionophores on prolactin gene expression in GH3 and 235-1 rat pituitary tumor cells.
pubmed:affiliation
Department of Anatomy, University of Connecticut Health Center, Farmington 06030.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.