Figure 2.

Regulation of Nrf2 transcriptional activity by Keap1. Nrf2 activity and hence the expression of its target genes is maintained at low levels by Keap1 under normal homeostatic conditions, but increases rapidly in response to redox and electrophilic stressors as well as by stimulation by growth factors. Cys151 is required for triggering Nrf2 signaling by activating agents, and Cys273 and Cys288 are functionally important for the sensing of inducers [56]. The biological effects of Nrf2 are exerted through its ability to mediate the induction of genes containing an antioxidant response element (ARE) in their promoter region upon exposure to a broad spectrum of oxidants and eletrophiles.