Identification of a ras-Activated Enhancer in the Mouse Osteopontin Promoter and Its Interaction with a Putative ETS-Related Transcription Factor Whose Activity Correlates with the Metastatic Potential of the Cell
Open Access
- 1 January 1995
- journal article
- research article
- Published by Taylor & Francis in Molecular and Cellular Biology
- Vol. 15 (1), 476-487
- https://doi.org/10.1128/mcb.15.1.476
Abstract
The role of RAS in transducing signals from an activated receptor into altered gene expression is becoming clear, though some links in the chain are still missing. Cells possessing activated RAS express higher levels of osteopontin (OPN), an alpha v beta 3 integrin-binding secreted phosphoprotein implicated in a number of developmental, physiological, and pathological processes. We report that in T24 H-ras-transformed NIH 3T3 cells enhanced transcription contributes to the increased expression of OPN. Transient transfection studies, DNA-protein binding assays, and methylation protection experiments have identified a novel ras-activated enhancer, distinct from known ras response elements, that appears responsible for part of the increase in OPN transcription in cells with an activated RAS. In electrophoretic mobility shift assays, the protein-binding motif GGAGGCAGG was found to be essential for the formation of several complexes, one of which (complex A) was generated at elevated levels by cell lines that are metastatic. Southwestern blotting and UV light cross-linking studies indicated the presence of several proteins able to interact with this sequence. The proteins that form these complexes have molecular masses estimated at approximately 16, 28, 32, 45, 80, and 100 kDa. Because the approximately 16-kDa protein was responsible for complex A formation, we have designated it MATF for metastasis-associated transcription factor. The GGANNNAGG motif is also found in some other promoters, suggesting that they may be similarly controlled by MATF.Keywords
This publication has 47 references indexed in Scilit:
- How receptors turn Ras onNature, 1993
- Tumor progression and metastasis in murine D2 hyperplastic alveolar nodule mammary tumor cell linesClinical & Experimental Metastasis, 1993
- Serum-, TPA-, and Ras-induced expression from Ap-1/Ets-driven promoters requires Raf-1 kinase.Genes & Development, 1992
- Secreted phosphoprotein mrna is induced during multi‐stage carcinogenesis in mouse skin and correlates with the metastatic potential of murine fibroblastsInternational Journal of Cancer, 1990
- A T Cell-Specific Transcriptional Enhancer within the Human T Cell Receptor δ LocusScience, 1990
- Clonal Heterogeneity, Experimental Metastatic Ability, and p21 Expression in H-ras-Transformed NIH 3T3 CellsJNCI Journal of the National Cancer Institute, 1988
- A small-scale procedure for preparation of nuclear extracts that support efficient transcription and pre-mRNA splicingGene Analysis Techniques, 1988
- A Harvey-ras responsive transcription element is also responsive to a tumour-promoter and to serumNature, 1988
- Gene regulation by steroid hormonesJournal of Steroid Biochemistry, 1987
- Inducible cellular transformation by a metallothionein-ras hybrid oncogene leads to natural killer cell susceptibilityNature, 1986