ATF2 encodes a transcription factor(activating transcription factor 2) that is a member of the leucine zipper family of DNA binding proteins. Activating transcription factor 2 has been identified as a moonlighting protein based on its ability to perform mechanistically distinct functions. Activating transcription factor 2 binds to the cAMP-responsive element (CRE), an octameric palindrome. It forms a homodimer or a heterodimer with c-Jun and stimulates CRE-dependent transcription. This protein is also a histone acetyltransferase (HAT) that specifically acetylates histones H2B and H4 in vitro; thus it may represent a class of sequence-specific factors that activate transcription by direct effects on chromatin components. Activating transcription factor 2 may also be involved in cell's DNA damage response independent of its role in transcriptional regulation. Several alternatively spliced transcript variants have been found for this ATF2.