Linked Life Data

7593254

Source:http://linkedlifedata.com/resource/pubmed/id/7593254

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-11-29
pubmed:abstractText
Organ culture of 19-day-old chick embryo duodena was utilized to evaluate the mechanism of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3)-dependent calbindin-D28k (CaBP) expression. Duodenal CaBP and 1,25(OH)2D3 receptor (VDR) expression were assessed by Western blot analysis, while CaBP and VDR mRNA levels were determined by Northern blot analysis. In untreated duodena, both VDR protein and mRNA were present, while CaBP protein and mRNA were undetectable. Treatment of cultured duodena with 25 nM 1,25(OH)2D3 resulted in detectable CaBP mRNA after 4 h which continued to increase during a 24 h time period. Under these conditions, localization of [3H-1 beta]1 alpha,25(OH)2D3 in duodenal chromatin is rapid (< or = 30 min). Thus, the delayed accumulation of detectable CaBP mRNA cannot be explained by slow nuclear binding of 1,25(OH)2D3. The inclusion of 1.6 microM actinomycin D in the organ culture partially inhibited the 1,25(OH)2D3-regulated increase in CaBP mRNA, which implies that there is a transcriptional component involved in the increased CaBP mRNA levels. Similarly, quantitative polymerase chain reaction studies allowed the detection of CaBP pre-mRNA and mRNA sequences 1 h after hormone treatment, suggesting that CaBP gene transcription is initiated rapidly. Treatment of cultures with 36 microM cycloheximide 1 h prior to 1,25(OH)2D3 addition resulted in superinduction of VDR mRNA levels but sharply reduced CaBP steady-state mRNA levels. This dramatic reduction in CaBP mRNA reveals that 1,25(OH)2D3-mediated CaBP expression is dependent on ongoing protein synthesis. Thus, we propose that a labile auxiliary protein or other cofactor, which may or may not be 1,25(OH)2D3-dependent, is necessary for 1,25(OH)2D3-mediated CaBP gene transcription in chick duodena.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0730-2312
pubmed:author
pubmed:issnType
Print
pubmed:volume
58
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
315-27
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
1,25(OH)2D3-dependent regulation of calbindin-D28k mRNA requires ongoing protein synthesis in chick duodenal organ culture.
pubmed:affiliation
Department of Biochemistry, University of Arizona, Tucson 85724, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.