Interactions of NF-kappaB with chromatin: the art of being at the right place at the right time.

Transcription factors of the NF-kappaB family are essential regulators of the inflammatory and immune responses. The main 'switch' in NF-kappaB activation is cytoplasmic and leads to the release of NF-kappaB proteins from IkappaB molecules, specific inhibitors that prevent their nuclear accumulation. However, it is becoming increasingly apparent that in addition to this required activation step, both recruitment of NF-kappaB to target genes and NF-kappaB-induced transcriptional events after recruitment are actively controlled. Regulated recruitment of NF-kappaB to chromatin generates kinetic complexity in NF-kappaB-dependent gene induction and 'wires' NF-kappaB-regulated gene activity to simultaneously activated pathways and transcription factors.