ISSN:
1040-452X
Keywords:
Embryonal carcinoma cells
;
Differentiation
;
Transcription
;
Transforming growth factor-beta
;
Activating transcription factor
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Previous studies demonstrated that differentiation of embryonal carcinoma (EC) cells increases the expression of the TGF-β2 gene and identified a CRE/ATF-like motif in the TGF-β2 promoter that is necessary for its activity. This suggested that differentiation may increase the transcription of this gene by differential binding of transcription factors to the CRE/ATF-like motif. To test this possibility, we performed gel mobility shift analysis using double-stranded oligodeoxynucleotides containing the TGF-β2 CRE/ATF-like motif and nuclear extracts prepared from F9 EC cells and F9-differentiated cells. We determined that the DNA/protein complexes formed by the EC nuclear extracts, but not the complexes formed by differentiated cell nuclear extracts, are recognized and supershifted by an ATF-1 specific antibody. This observation is consistent with our Western immunoblot analysis that detects ATF-1 in the EC cells, but not in their differentiated counterparts. In addition, we provide evidence that protein phosphorylation influences the formation of complexes between F9 nuclear proteins and the CRE/ATF-like motif. Together, our studies identify a likely role for the CRE/ATF-like motif in the regulation of TGF-β2 and suggest that this site binds one set of nuclear proteins in EC cells, where the gene is not expressed, and a different set of nuclear proteins in the differentiated cells, where the gene is expressed. © 1995 Wiley-Liss, Inc.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrd.1080400202
