C- fos gene expression in cell revertants from a transformed to a pseudonormal phenotype

Abstract

c- fos gene expression in two types of mouse sarcoma cells of spontaneous origin and in revertants to pseudonormal phenotype has been investigated. In the latter cells the content of c- fos mRNA is similar to that in normal fibroblasts. Activity of transcription factors interacting with the regulatory elements, SRE, DSE and TRE, in the c- fos promoter do not correlate with the c- fos mRNA concentration. However, experiments with cells transformed with the indicator plasmid, fos-CAT, showed that the 600 bp c-fos promoter region provides the chloramphenicol acetyltransferase activity correlating with c- fos mRNA expression in cell revertants to a pseudonormal phenotype.