Abate C, Patel L, Rauscher F J, Curran T
Department of Molecular Oncology and Virology, Roche Institute of Molecular Biology, Nutley, NJ 07110.
Science. 1990 Sep 7;249(4973):1157-61. doi: 10.1126/science.2118682.
The proto-oncogenes c-fos and c-jun function cooperatively as inducible transcription factors in signal transduction processes. Their protein products, Fos and Jun, form a heterodimeric complex that interacts with the DNA regulatory element known as the activator protein-1 (AP-1) binding site. Dimerization occurs via interaction between leucine zipper domains and serves to bring into proper juxtaposition a region in each protein that is rich in basic amino acids and that forms a DNA-binding domain. DNA binding of the Fos-Jun heterodimer was modulated by reduction-oxidation (redox) of a single conserved cysteine residue in the DNA-binding domains of the two proteins. Furthermore, a nuclear protein was identified that reduced Fos and Jun and stimulated DNA-binding activity in vitro. These results suggest that transcriptional activity mediated by AP-1 binding factors may be regulated by a redox mechanism.
