Viral and cellular fos proteins: a comparative analysis.

Publication Type:

Journal Article


Cell, Volume 36, Issue 2, p.259-68 (1984)


362, Amnion, Animals, Cell Line, Cricetinae, Cricetulus, DNA Restriction Enzymes, DNA, Recombinant, Female, GENE AMPLIFICATION, GENES, Genes, Viral, MICE, Oncogenes, Ovary, Plasmids, PREGNANCY, Tetrahydrofolate Dehydrogenase, Transfection, Viral Proteins


The FBJ murine osteosarcoma virus (FBJ-MuSV) induces osteosarcomas in mice and transforms fibroblasts in vitro. It contains an oncogene termed v-fos derived from a normal cellular gene by recombination with an associated helper virus. The product of the v-fos gene is a 55,000 dalton protein, p55v-fos. This protein was found in the nuclei of cells containing amplified levels of the v-fos gene, and also in the nuclei of virus-transformed cells. The c-fos protein was localized in the nuclei of normal mouse amnion cells and in the nuclei of cells transformed by a recombinant plasmid that expresses the c-fos gene product. However, p55c-fos undergoes more extensive post-translational modification in the nucleus than p55v-fos. Immunofluorescence data indicate that the level of p55c-fos in normal mouse amnion cells is similar to that found in fibroblasts transformed by the v-fos or c-fos proteins.