Activation of the c-fos serum-response element by the activated c-Ha-ras protein in a manner independent of protein kinase C and cAMP-dependent protein kinase.
12-O-Tetradecanoylphorbol-13-acetate (TPA) activated the c-fos gene enhancer linked to the chloramphenicol acetyltransferase or luciferase reporter gene in the wild type PC-12 cells but not in the variant PC-12 cells that originated from the wild type cells. Transfection of the c-Ha-rasval12 complementary DNA (cDNA) or addition of dibutyryl cAMP to the wild type PC-12 cells as well as to the variant PC-12 cells activated the c-fos gene enhancer. Prolonged treatment of the wild type PC-12 cells with phorbol-12,13-dibutyrate caused down-regulation of protein kinase C. In these cells, TPA did not stimulate the c-fos gene enhancer any more, but transfection of the c-Ha-rasval12 cDNA still stimulated the c-fos gene enhancer to the same extent as induced in the control cells. Transfection of the c-Ha-rasval12 cDNA or addition of TPA to the wild type PC-12 cells stimulated the serum-response element but not the cAMP-response element. Dibutyryl cAMP stimulated both the serum-response element and the cAMP-response element in the wild type PC-12 cells. These results indicate that the c-Ha-rasval12 protein activates the serum-response element, but not the cAMP-response element in the c-fos gene enhancer, and that the signal pathway from the c-Ha-rasval12 protein to the c-fos serum-response element is independent of protein kinase C and cAMP-dependent protein kinase.
Department of Biochemistry, Kobe University School of Medicine, Japan.
Y
Y
Fukumoto
K
K
Kaibuchi
N
N
Oku
Y
Y
Hori
Y
Y
Takai
D015153:Blotting, Western; D002478:Cells, Cultured; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000235:genetics; D015536:Down-Regulation; D004591:Electrophoresis, Polyacrylamide Gel; D015971:Gene Expression Regulation, Enzymologic; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D010957:Plasmids; D011493:Protein Kinase C / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras); D011519:Proto-Oncogenes; D026362:Serum Response Factor; D014162:Transfection
D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D026362:Serum Response Factor; D015240:Phorbol 12,13-Dibutyrate; D004247:DNA; D008156:Luciferases; D015500:Chloramphenicol O-Acetyltransferase; D011493:Protein Kinase C; D016283:Proto-Oncogene Proteins p21(ras)