Activating transcription factor 2 (ATF-2) is a transcriptional activator, probably constitutive, which binds to the cAMP-responsive element (CRE) consensus sequence: 5-GTGACGT[AC][AG]-3, a sequence present in many viral and cellular promoters.ATF-2 binds DNA as a dimer and can form a homodimer in the absence of DNA. ATF-2 can form a heterodimer with JUN, and interacts with SMAD3 and SMAD4.