Transcriptional regulator, potentially with dual roles in transcription initiation and termination. Binds DNA and functions as a transcriptional activator (PubMed:12270922). Binds to two G/A-rich sites, ME1a1 and ME1a2, within the MYC promoter having greater affinity for the former (PubMed:1502157). Also binds to multiple G/C-rich sites within the promoter of the Sp1 family of transcription factors (PubMed:1502157). Binds DNA and functions as a transcriptional activator (PubMed:12270922). Inhibits MAZ isoform 1-mediated transcription (PubMed:12270922). Binds DNA and functions as a transcriptional activator. Interacts with BPTF. Forms a heterodimer with MAZ isoform 2; the interaction inhibits MAZ isoform 1-mediated transcription activation. Forms a heterodimer with MAZ isoform 1; the interaction inhibits MAZ isoform 1-mediated transcription activation. In brains of Alzheimer disease patients, present in a plaque-like structures. Present in kidney, liver and brain. In the brain, highest levels are found in motor cortex and midfrontal cortex (at protein level). Expressed in the heart, brain, placenta, lung, liver, skeletal muscle and weakly expressed in the kidney (PubMed:1502157). Expressed in the joint synovium (PubMed:19583771). Induced by cytokine and growth factor stimulation. May act as a dominant negative of isoform 1. Reduced expression during inflammatory conditions. The transactivation potential of isoform 3 is much greater than that of the predominantly expressed isoform 1.