NRF2 signaling in cytoprotection and metabolism

The KEAP1-NRF2 system plays a central role in cytoprotection and defense mechanisms against oxidative stress. Because KEAP1 serves as a biosensor for electrophiles by using its reactive thiols and because NRF2 is a transcriptional factor regulating genes involved in the sulfur-mediated redox reactions, the KEAP1-NRF2 system has been regarded as a sulfur-utilizing cytoprotective mechanism. NRF2 is a key regulator of cytoprotective genes, such as antioxidant and detoxification genes, and also to possess potent anti-inflammatory activity. NRF2 has been recently focused as a great modifier/regulator for the cellular metabolism and mitochondrial function. Particularly, the NRF2-mediated regulatory mechanisms of metabolites and mitochondria has been considered diverse, but has not been fully-clarified yet. This review article provides an overview of the molecular mechanisms that regulate NRF2 signaling and its cytoprotective roles, and also highlights NRF2 contribution to the cellular metabolism, particularly in the context of mitochondrial function and newly found sulfur metabolism.