c-Jun/AP-1 (Transcription factor AP-1) forms the AP-1 early response transcription factor in combination with c-Fos. It is activated by double phosphorylation via the JNK pathway, and by PRKDC, but also has a phosphorylation-independent function. c-Jun binds to the enhancer heptamer motif 5'TGA[CG]TCA-3'. It interacts with numerous proteins that may effect its activity including but not limited to FOS, BATF3, HIVEP3, SMAD3/SMAD4, MYBBP1A, SP1, SPIB, TCF20, COPS5, DSIPI, THIF1, ERG, CREB binding protein, Retinoblastoma protein, BRCA1, TATA binding protein, MAPK8, RUNX proteins, STAT1, BCL.