DNA-bound Fos proteins activate transcription in yeast.
We constructed genes encoding the DNA binding region of the bacterial LexA repressor fused to the v-fos and c-fos oncogene products. The resulting LexA-Fos fusion proteins activated transcription in yeast. Transcription activation by these proteins was as strong as transcription activation by proteins native to yeast. LexA-Fos fusion proteins only activated transcription of genes when they were bound to LexA binding sites inserted upstream of those genes. Transcription was activated less strongly by similar proteins in which the DNA binding region of LexA was fused to vMyc and cMyc. Transcription was not activated by native LexA or by proteins containing the DNA binding domain of LexA fused to bacteriophage 434 repressor or yeast MAT alpha 2 protein. These results demonstrate that Fos proteins activate eukaryotic gene expression when they are bound to promoter DNA, and thus suggest that Fos proteins exert some of their effects because they stimulate transcription of cellular genes. Regulation of transcription by Fos and Myc proteins in yeast provides a phenotype that may facilitate genetic analysis of the function of these proteins in higher organisms.
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000378:metabolism*; D004274:DNA, Recombinant; D004268:DNA-Binding Proteins; D015683:Gene Products, gag; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D016274:Oncogene Protein p55(v-myc); D010957:Plasmids; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos; D016271:Proto-Oncogene Proteins c-myc; D011993:Recombinant Fusion Proteins / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics*; D012097:Repressor Proteins; D012191:Retroviridae Proteins / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D012697:Serine Endopeptidases; D014158:Transcription, Genetic; D000099160:LexA Repressor Protein
D001426:Bacterial Proteins; D004247:DNA; D004274:DNA, Recombinant; D004268:DNA-Binding Proteins; D015683:Gene Products, gag; D016274:Oncogene Protein p55(v-myc); D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D016271:Proto-Oncogene Proteins c-myc; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D012191:Retroviridae Proteins; D012697:Serine Endopeptidases; D000099160:LexA Repressor Protein