Plays important functions in early cell signaling. Binds the cAMP response element (CRE) (consensus: 5-GTGACGT[AG][AG]-3), a sequence present in many viral and cellular promoters. Activator of the NF-ELAM1/delta-A site of the E-selectin promoter. Has no intrinsic transcriptional activity, but activates transcription on formation of JUN or FOS heterodimers.