Modulation of the composition of AP-1 complex and its impact on transcriptional activity

AP-1 transcription factor known to play a role in cell proliferation and ne uronal activation, it is also involved in apoptosis of cells in response to stress, DNA damaging agents or lack of survival signals. AP-1 DNA binding complex is not a single transcritpion factor but a dimer consisting of memb ers of Fos and Jun families. Ln this review, we discuss evidence that compo sition of the AP-1 complex is different under various physiological and pat hophysiological conditions. Furthermore, we describe biochemical properties of Fos and Jun proteins that may explain the ability of this transcription factor to activate different sets of genes in response to different stimul i. We propose a hypothesis that AP-1 might contribute to distinct biologica l processes because an activation of specific signaling pathways results in changes of AP-1 composition and/or phosphorylation status and modulates it s transactivating potential towards different promoters.