Transforming p21 Mutants and c-Ets-2 Activate the Cyclin D1 Promoter through Distinguishable Regions

作者：Chris Albanese, Janet Johnson, Genichi Watanabe, Nathan Eklund, Dzuy Vu, Andrew Arnold, Richard G. Pestell · 发表于：Journal of Biological Chemistry · 年份：1995 · DOI：10.1074/jbc.270.40.23589 · 被引用次数：808 · 研究领域：Cancer-related Molecular Pathways、Epigenetics and DNA Methylation、Cancer-related gene regulation

Several different oncogenes and growth factors promote G1 phase progression. Cyclin D1, the regulatory subunit of several cyclin-dependent kinases, is required for, and capable of shortening, the G1 phase of the cell cycle. The present study demonstrates that transforming mutants of p21ras (Ras Val-12, Ras Leu-61) induce the cyclin D1 promoter in human trophoblasts (JEG-3), mink lung epithelial (Mv1.Lu), and in Chinese hamster ovary fibroblast cell lines. Site-directed mutagenesis of AP-1-like sequences at -954 abolished p21ras-dependent activation of cyclin D1 expression. The AP-1-like sequences were also required for activation of the cyclin D1 promoter by c-Jun. In electrophoretic mobility shift assays using nuclear extracts from cultured cells and primary tissues, several AP-1 proteins (c-Jun, JunB, JunD, and c-Fos) bound the cyclin D1 -954 region. Cyclin D1 promoter activity was stimulated by overexpression of mitogen-activated protein kinase (p41MAPK) or c-Ets-2 through the proximal 22 base pairs. Expression of plasmids encoding either dominant negative MAPK (p41MAPKi) or dominant negatives of ETS activation (Ets-LacZ), antagonized MAPK-dependent induction of cyclin D1 promoter activity. Epidermal growth factor induction of cyclin D1 transcription, through the proximal promoter region, was antagonized by either p41MAPKi or Ets-LacZ, suggesting that ETS functions downstream of epidermal growth factor and MAPK in the context of the cyclin D1 promoter. The activation of cy...