Signaling pathways activated by the phytochemical nordihydroguaiaretic acid contribute to a Keap1-independent regulation of Nrf2 stability: Role of glycogen synthase kinase-3

► Transcription factor Nrf2 controls cell response to oxidant stress ► Nrf2 stability depends on two E3 ubiquitin ligase adaptors: Keap1 and β-TrCP ► Cancer chemopreventive compound NDGA inhibits both Keap1 and GSK-3/β-TrCP ► GSK-3 is an integrator of signaling kinases connecting xenobiotics to Nrf2 ► The Nrf2/HO-1 axis induced by NDGA protects against hydrogen peroxide