AP-1: One Switch for Many Signals

Transcription factors control invasion: AP-1 the first among equals

“…Many human tumor cells carry activated oncogenes that function in the growth factor oncogene signal transduction pathway that require AP-1 activity for transformation and, as a consequence, AP-1 activity is high in a large variety of human tumor cells (Wisdom, 1999;Ozanne et al, 2000;Milde-Langosch, 2005). This, along with the AP-1-mediated invasion program seen in fibroblast model systems, suggests that …”

“…It is possible that the transactivation activity is supplied by other transcription factors that cooperate with AP-1 to regulate gene expression. AP-1 dimers can synergize with a variety of other transcription factors (Nolan, 1994;Wisdom, 1999). This can be achieved by direct physical interaction of these transcription factors with c-Jun via a small region upstream of the DNA binding domain (Bassunk and Leiden, 1995).…”

Distinct roles of Jun : Fos and Jun : ATF dimers in oncogenesis

“…c-Fos and Fra-1 can heterodimerize with ATF4, but not with ATF2 and ATF3 (Ivashkiv et al, 1990;Benbrook and Jones, 1990;Chatton et al, 1994;Hai and Curran, 1991). Both ATF2 homodimers McCarthy et al (1995) and Wisdom (1999) and c-Jun : ATF2 heterodimers bind with high a nity to degenerated ATF sites with the consensus motif T G / T A CN TCA (Figure 1). However, c-Jun : ATF2 and ATF2 : ATF2 show di erences in their relatively a nities for more degenerated 8 bp ATF-like motifs Jones, 1990, 1994).…”

“…Here, we will review the di erences between the Jun : Jun, Jun : Fos and Jun : ATF classes of AP-1 dimers with emphasis on their roles in oncogenic transformation in avian model systems. Previous reviews on AP-1 and cell transformation include references: (Angel and Karin, 1991;Wisdom, 1999;Vogt, 1994;Karin et al, 1997;van Dam and van der Eb, 1994;Hagmeyer et al, 1995).…”

Recent insights into the mechanism of glucocorticosteroid-induced apoptosis

“…Since the AP-1 transcription factor regulates expression of genes involved in cell growth, differentiation and transformation, 3,4 their findings suggested that interference with transcription factors required for cell survival, such as AP-1 (activating protein-1), may contribute to apoptosis induction. 2 This interpretation is consistent with earlier findings indicating that in cytokine (IL-2)-dependent CTLL cells there is a correlation between the presence of AP-1 DNA binding activity and repression of corticosteroid-induced apoptosis.…”