Linked Life Data

8753804

Source:http://linkedlifedata.com/resource/pubmed/id/8753804

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-10-10
pubmed:abstractText
The activity of the rat CYP7A/luciferase reporter gene was increased five-fold by all-trans retinoic acid (atRA) or 9-cis retinoic acid (9cRA) in transient transfection assay in HepG2 cells. Cotransfection with retinoid X receptor (RXR) stimulated the promoter activity in the absence of ligand, however, addition of atRA inhibited the transcriptional activity. Cotransfection with retinoic acid receptor (RAR) did not have much effect on CYP7A promoter activity. The CYP7A promoter, when linked upstream to the SV40/ luciferase reporter gene, strongly repressed the phorbol 12-myristate 13-acetate (PMA)-stimulated SV40/ luciferase reporter gene activity. The regions conferring the effects of RA and PMA were mapped to nt-176/ -117 and nt-148/-129, respectively. Several direct repeats of hormone response element (AGTTCA) in this region are required for RA response. AP-1 like sequences are located within the region responding to both RA and PMA. Site-directed mutagenesis of the AP-1 site abolished the effects of both RA and phorbol esters. Retinoic acid effect was antagonized by PMA. Moreover, cotransfection of Fos and Jun expression vectors blunted the stimulatory effect of retinoic acid on the CYP7A/luciferase gene activity. Therefore, effects of two different signal transduction pathways converge to a common response element. This regulatory cross-talk may be involved in bile acid repression and regulates CYP7 gene transcription in the liver.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-291X
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
225
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
585-92
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
The opposing effects of retinoic acid and phorbol esters converge to a common response element in the promoter of the rat cholesterol 7 alpha-hydroxylase gene (CYP7A).
pubmed:affiliation
Department of Biochemistry and Molecular Pathology, Northeastern Ohio Universities College of Medicine, Rootstown 44272-0095, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't