v-fos FBJ murine osteosarcoma viral oncogene homolog Adenovirus

The activator protein-1 (AP-1) transcription factor consists of either Jun homodimers or Fos/Jun heterodimeric complexes, which bind the palindromic TRE sequence TGA(C/G)TCA. The Jun family includes c-Jun, Jun B and Jun D, while the Fos gene family members include c-Fos, Fos B, Fra-1 and Fra-2. In addition, certain ATF/CREB proteins form leucine zipper dimers with Fos and Jun, which exhibit different specificities for AP-1 and CRE DNA motifs. AP-1 transcription factor components are subject to regulation by both phosphorylation and by chemical oxidation of specific cysteine residues mapping within the DNA binding domains of Fos and Jun. Oxidation is reversible by a cellular redox/DNA repair protein designated Ref-1 (redox factor 1). JAB1 (Jun-activation domain-binding protein 1) potentiates transcription by either c-Jun or Jun D.