TRANSCRIPTIONAL REGULATION IN THE IMMUNE-SYSTEM - ALL ROADS LEAD TO AP-1

The mechanisms regulating the development and function of the immune s ystem are diverse and complicated. The signaling pathways and target g enes that become activated upon cell-surface stimulation are currently being defined, and transcription factor activator protein 1 (AP-1) is proving to be an important regulator of nuclear gene expression in le ukocytes. In vitro and in vivo studies have demonstrated that AP-1 exp ression is induced after a diverse range of stimuli and that AP-I cont ributes to the regulation of a large number of genes. In this review w e will examine the role of AP-1 during leukocyte activation and differ entiation in the immune system.