Molecular mechanisms of Nrf2-mediated antioxidant response.
Nrf2 is the key transcription factor regulating the antioxidant response. Nrf2 signaling is repressed by Keap1 at basal condition and induced by oxidative stress. Keap1 is recently identified as a Cullin 3-dependent substrate adaptor protein. A two-sites binding "hinge & latch" model vividly depicts how Keap1 can efficiently present Nrf2 as substrate for ubiquitination. Oxidative perturbation can impede Keap1-mediated Nrf2 ubiquitination but fail to disrupt Nrf2/Keap1 binding. Nrf2 per se is a redox-sensitive transcription factor. A new Nrf2-mediated redox signaling model is proposed based on these new discoveries. Free floating Nrf2 protein functions as a redox-sensitive probe. Keap1 instead functions as a gate keeper to control the availability of Nrf2 probes and thus regulates the overall sensitivity of the redox signaling.
Li
Wenge
W
Department of Pharmaceutics, Ernest-Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA.
Kong
Ah-Ng
AN
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism / Q000502:physiology; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2 / Q000378:metabolism / Q000502:physiology*; D018384:Oxidative Stress; D011485:Protein Binding; D015398:Signal Transduction
D000975:Antioxidants; D047908:Intracellular Signaling Peptides and Proteins; C431364:KEAP1 protein, human; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human