Transcriptional activation encoded by the v-fos gene.
We present evidence that the fos oncogene encodes a transcriptional trans-activation function. trans-activation was assayed by cotransfection into NIH 3T3 mouse fibroblasts of v-fos DNA containing plasmids together with a plasmid containing a test promoter. Three v-fos DNAs were used: (i) pFBR-1, a plasmid containing the FBR proviral sequences; (ii) pFBJ-2, a plasmid harboring the FBJ proviral sequences; (iii) pMF-J, a plasmid containing the FBJ fos sequences linked to a mouse metallothionein promoter. Each of the three v-fos DNA plasmids stimulated the expression of a cotransfected chimeric gene consisting of a promoter segment of the mouse alpha 1(III) collagen gene linked to the gene for chloramphenicol transacetylase. In similar experiments the v-fos gene also stimulated the long terminal repeat promoter of Rous sarcoma virus (RSV) but neither the early promoter of simian virus 40 nor the beta-actin promoter. Evidence that the trans-activation function is specified by the v-fos coding sequences comes from the fact that a frameshift mutation in the v-fos coding sequence inhibits the trans-activation. Two mutations that map around nucleotide -100 in the RSV promoter do not respond to cotransfection with v-fos, whereas other mutations respond like the wild-type RSV promoter. These experiments suggest that the v-fos gene either encodes or induces an activator of transcription that recognizes specific sequences in promoters.
D000818:Animals; D001358:Avian Sarcoma Viruses / Q000235:genetics*; D002460:Cell Line; D003001:Cloning, Molecular; D003094:Collagen / Q000235:genetics*; D005786:Gene Expression Regulation; D051379:Mice; D009856:Oncogene Proteins, Viral / Q000235:genetics; D009857:Oncogenes; D011401:Promoter Regions, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
D009856:Oncogene Proteins, Viral; D014157:Transcription Factors; D003094:Collagen