Activator protein-1 contributes to high NaCl-induced increase in tonicity-responsive enhancer/osmotic response element-binding protein transactivating activity.

Tonicity-responsive enhancer/osmotic response element-binding protein (TonEBP/OREBP) is a Rel protein that activates transcription of osmoprotective genes at high extracellular NaCl. Other Rel proteins NFAT1-4 and NF-kappaB complex with activator protein-1 (AP-1) to transactivate target genes through interaction at composite NFAT/NF-kappaB.AP-1 sites.