AP-1 (activating protein-1) is a collective term referring to dimeric transcription factors composed of Jun, Fos or ATF (activating transcription factor) subunits that bind to a common DNA site, the AP-1-binding site.) AP-1 regulates a wide range of cellular processes, including cell proliferation, death, survival and differentiation.
Increased AP-1 levels lead to increased transactivation of target gene expression. Regulation of AP-1 activity is therefore critical for cell function and occurs through specific interactions controlled by dimer-composition, transcriptional and post-translational events, and interaction with accessory proteins. AP-1 functions are heavily dependent on the specific Fos and Jun subunits contributing to AP-1 dimers. The outcome of AP-1 activation is dependent on the complex combinatorial patterns of AP-1 component dimers. The AP-1 complex binds to a palindromic DNA motif (5’-TGA G/C TCA-3’) to regulate gene expression, but specificity is dependent on the dimer composition of the bZIP subunit.
