Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
2001-7-16
pubmed:abstractText
Activating transcription factor 3 (ATF3) is an early response gene that is induced rapidly during in vivo situations of cellular growth such as liver regeneration. However, neither the physiological function nor the potential target genes of this transcription factor related to cellular proliferation have been identified in the liver or other tissues. We demonstrate here that endogenous ATF3 mRNA expression is rapidly induced up to 4-fold upon mitogenic stimulation of quiescent Hepa 1-6 mouse hepatoma cells. Overexpression of exogenous ATF3 results in a significant, dose-dependent increase in DNA synthesis of up to 140% over control cells. ATF3-transfected cells also display significantly higher rates of [(3)H]thymidine incorporation in comparison with nontransfected controls in the presence of serum. Northern blot analysis and co-transfection experiments demonstrate that overexpression of ATF3 enhances cyclin D1 mRNA expression and activates the cyclin D1 promoter 2.5-fold when activating protein-1 (AP-1) and cyclic AMP response element (CRE) sites within the promoter are intact. ATF3-mediated promoter activation is reduced to 1.3-fold and 1.6-fold respectively when the AP-1 or CRE sites are mutated, and mutation of both sites simultaneously leads to the complete abrogation of promoter activation. Furthermore, DNA-binding studies demonstrate that ATF3 binds directly to the AP-1 site within the cyclin D1 promoter. These results indicate that ATF3 expression stimulates hepatocellular proliferation, suggesting that this effect is mediated, at least in part, by the ATF3-dependent activation of cyclin D1 transcription.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
27272-80
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Activating transcription factor 3 induces DNA synthesis and expression of cyclin D1 in hepatocytes.
pubmed:affiliation
Department of Biomedical Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.