Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
1999-4-27
pubmed:abstractText
Transforming growth factor beta (TGFbeta) activates transcription of the plasminogen activator inhibitor type-1 (PAI-1) gene through a major TGFbeta-responsive region (-740 and -647) in the PAI-1 promoter. This process requires the Smad family of signaling molecules. Upon phosphorylation by the TGFbeta receptors, Smad2 and Smad3 homoligomerize and heteroligomerize with Smad4, translocate to the nucleus and activate transcription of TGFbeta responsive genes. Smad3 and Smad4 have been shown to bind to various sites in the PAI-1 promoter. To determine the number of Smad-binding sites within the 94-base pair major TGFbeta-responsive region and the mechanism of Smad-mediated transactivation, we systematically mapped the Smad-binding sites and show that Smad4 and Smad3 bind cooperatively to two adjacent DNA elements in this region. Both elements were required for TGFbeta-induced, Smad3- and Smad4-dependent activation of PAI-1 transcription. Contrary to previous reports, transactivation of the PAI-1 promoter was mediated by the amino- but not carboxyl-terminal domains of the Smads. Furthermore, oligomerization of Smad3 markedly enhanced its binding to the two binding sites. Finally, a Smad4 mutation identified in a human pancreatic carcinoma that inactivates Smad4 signaling abolished Smad4 DNA binding activity, hence preventing transactivation of TGFbeta-responsive genes. These results underscore the importance of the Smad4 DNA binding activity in controlling cell growth and carcinogenesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9431-41
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Cooperative binding of Smad proteins to two adjacent DNA elements in the plasminogen activator inhibitor-1 promoter mediates transforming growth factor beta-induced smad-dependent transcriptional activation.
pubmed:affiliation
Life Sciences Division, Lawrence Berkeley National Laboratory and Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.