The product of a novel growth factor activated gene, fos B, interacts with JUN proteins enhancing their DNA binding activity.

AUTOR(ES)

Zerial, M

RESUMO

We have identified a gene, fos B, encoding a nuclear protein of 338 amino acids presenting a 70% homology with c-fos, whose expression is activated during G0/G1 transition. Growth factor stimulation of quiescent cells leads to a rapid and transient accumulation of fos B mRNA, with kinetics similar to those of c-fos. The induction of fos B mRNA levels is in part due to a dramatic increase in the transcription of the gene. The half-life of fos B mRNA is in the order of 10-15 min. Both transcriptional activation and mRNA stability are substantially increased in the presence of protein synthesis inhibitors. Immunoprecipitation studies showed that fos B as c-fos protein, forms a complex in vitro with c-jun and jun B proteins in the absence of a target binding sequence. Gel retardation assays demonstrated that fos B protein positively influences the binding of c-jun and jun B proteins to an AP-1 binding consensus sequence, suggesting that fos B protein plays a role in control of gene expression.

Documentos Relacionados

• The product of a novel growth factor-activated gene, fic, is a biologically active "C-C"-type cytokine.
• Transformation by the fos or jun oncogene does not increase AP-1 DNA-binding activity.
• The von Hippel-Lindau tumor suppressor gene product interacts with Sp1 to repress vascular endothelial growth factor promoter activity.
• Heparin-binding epidermal growth factor-like growth factor, a v-Jun target gene, induces oncogenic transformation
• The amphiregulin gene encodes a novel epidermal growth factor-related protein with tumor-inhibitory activity.