Isoform E is a PKA-dependent transcriptional activator. Isoform J is a direct antagonist of activation by isoform E in cell culture. Binds the cAMP response element (CRE) (consensus: 5'-GTGACGT[AC][AG]-3'), a sequence present in many viral and cellular promoters (PubMed:7651429, PubMed:15219829). Has a role in long-term memory (PubMed:29473541). Homodimer. Most cells of the adult brain; cell bodies, but not neuropil. Throughout development with lowest levels in first larval instar and late pupae. RNAi-mediated knockdown in the mushroom bodies results in a reduction in long-term memory performance, but does not affect anesthesia-resistant memory (ARM) or learning ability. Isolated from Schneider 2 cells. Belongs to the bZIP family. ATF subfamily.