Difference in transcriptional regulatory function between c-Fos and Fra-2.
AUTOR(ES)
Suzuki, T
RESUMO
Fra-2, one of the Fos-related antigens, is promptly expressed after the growth stimulation of fibroblasts, but its induction peak is later than that of c-Fos. In this report, we examined biochemical properties of Fra-2 and compared them with those of two other Fos family proteins, c-Fos and Fra-1. Like c-Fos and Fra-1, Fra-2 formed stable heterodimers with c-Jun, JunB or JunD in vitro and all these complexes had specific DNA-binding activity to AP-1-binding sites (AP-1 sites) or related sequences. When transiently introduced into a mouse embryonic carcinoma cell line, F9, with reporter genes containing the AP-1 site from the collagenase gene, fra-2 plus c-jun suppressed the transactivation by c-jun alone. This property of Fra-2 is in clear contrast to that of c-Fos, which stimulates the transcriptional activity of c-Jun by forming a stable heterodimer. Analysis of chimeric proteins between c-Fos and Fra-2 indicated that this difference is mainly attributable to their C terminal-half regions. Interestingly, this suppressive effect of Fra-2 was not observed in the combination with JunD: fra-2 plus junD, like c-fos plus junD, had higher transcriptional activity than junD alone. Fra-1 showed essentially the same transcriptional regulatory properties as Fra-2. These differential properties greatly expand the potential range of regulatory functions of the Fos family proteins.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=328954Documentos Relacionados
- Calcium and growth factor pathways of c-fos transcriptional activation require distinct upstream regulatory sequences.
- Serum stimulation of the c-fos enhancer induces reversible changes in c-fos chromatin structure.
- Transcriptional and posttranscriptional control of c-fos gene expression in human monocytes.
- Inducible binding of a factor to the c-fos regulatory region.
- c-fos transcriptional activation and repression correlate temporally with the phosphorylation status of TCF.