Activation of the AP-1 family of transcription factors Activator protein-1 (AP-1) is a collective term referring to a group of transcription factors that bind to promoters of target genes in a sequence-specific manner. AP-1 family consists of hetero- and homodimers of bZIP (basic region leucine zipper) proteins, mainly of Jun-Jun, Jun-Fos or Jun-ATF. <p>AP-1 members are involved in the regulation of a number of cellular processes including cell growth, proliferation, survival, apoptosis, differentiation, cell migration. The ability of a single transcription factor to determine a cell fate critically depends on the relative abundance of AP-1 subunits, the composition of AP-1 dimers, the quality of stimulus, the cell type, the co-factor assembly. </p><p>AP-1 activity is regulated on multiple levels; transcriptional, translational and post-translational control mechanisms contribute to the balanced production of AP-1 proteins and their functions. Briefly, regulation occurs through:<ol><li>effects on jun, fos, atf gene transcription and mRNA turnover.<li> AP-1 protein members turnover. <li>post-translational modifications of AP-1 proteins that modulate their transactivation potential (effect of protein kinases or phosphatases).<li>interactions with other transcription factors that can either induce or interfere with AP-1 activity.</ol> Authored: Shamovsky, V, 2009-12-16 Edited: Shamovsky, V, 2010-02-27 GENE ONTOLOGYGO:0051090 Pubmed15564374 Pubmed19167516 Pubmed7622446 Pubmed9069263 Reactome Database ID Release 43450341 Reactome, http://www.reactome.org ReactomeREACT_21326 Reviewed: Gillespie, ME, 2010-02-27 PathwayStep3482 PathwayStep3480 PathwayStep3481 PathwayStep3479 PathwayStep3478 Phosphorylated MAPKs phosphorylate ATF-2 Activated JNKs phosphorylate c-JUN c-FOS activation by phospho ERK1/2 Formation of Activated Protein 1 (AP-1) complex. ATF2/c-JUN heterodimer. Formation of Activated Protein 1 (AP-1) complex. cFOS/c-JUN heterodimer.