TGF-beta attenuates the transactivation activity of Ets-1 despite its induction via the inhibition of DNA binding.
We examined whether TGF-fl affects the transactivation activity of Ets-1. TGF-beta augmented ets-1 mRNA expression and Ets-1 protein synthesis in ECV304 cells to the level equivalent to bFGF. When the DNA binding activity of Ets-1 protein was examined, bFGF was found to enhance DNA-Ets complex formation, whereas TGF-beta attenuated basal as well as bFGF-enhanced DNA-Ets complex formation. As a result, TGF-beta attenuated the promoter activity driven by Ets-1. The DNA binding of Ets-1 protein was enhanced by the initial 4-hour bFGF treatment and the subsequent 8-hour cycloheximide treatment. When TGF-beta replaced cycloheximide in the subsequent 8-hour treatment, TGF-beta inhibited this bFGF-enhanced DNA-Ets complex formation. When TGF-beta and cycloheximide were simultaneously added in the subsequent 8-hour treatment, the inhibitory effect of TGF-beta on bFGF-enhanced DNA-Ets complex formation was completely abolished. These results suggest the possibility that TGF-beta attenuates the transactivation activity of Ets-1 by inducing a protein that interferes with the binding of Ets-1 to the DNA binding site.
Iwasaka-Yagi
C
C
Department of Vascular Biology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
Abe
M
M
Sato
Y
Y
D002461:Cell Line, Transformed; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000378:metabolism*; D003864:Depression, Chemical; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D017930:Genes, Reporter; D006801:Humans; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D020781:Matrix Metalloproteinase 1 / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D050784:Proto-Oncogene Protein c-ets-1; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D014157:Transcription Factors / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects*; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D016895:Culture Media, Serum-Free; C494041:ETS1 protein, human; D011500:Protein Synthesis Inhibitors; D050784:Proto-Oncogene Protein c-ets-1; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D016222:Fibroblast Growth Factor 2; D004247:DNA; D003513:Cycloheximide; D008156:Luciferases; D020781:Matrix Metalloproteinase 1