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-ras(val12) 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-ras(val12) cDNA still stimulated the c-fos gene enhancer to the same extent as induced in the control cells. Transfection of the c-Ha-ras(val12) 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-ras(va112) 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-ras(va112) protein to the c-fos serum-response element is independent of protein kinase C and cAMP-dependent protein kinase.
|Number of pages||7|
|Journal||Journal of Biological Chemistry|
|Publication status||Published - 1990|
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology