Scaffolding of Keap1 to the actin cytoskeleton controls the function of Nrf2 as key regulator of cytoprotective phase 2 genes

• DOI: 10.1073/pnas.0308347100
• Publication Date: 2004-02-17T20:32:02Z
• Authors: Moon-Il Kang; Akira Kobayashi; Nobunao Wakabayashi; Sang-Geon Kim; Masayuki Yamamoto
• Keywords: KEAP1; Immunoprecipitation

Transcription factor Nrf2 regulates basal and inducible expression of phase 2 proteins that protect animal cells against the toxic effects electrophiles oxidants. Under conditions, is sequestered in cytoplasm by Keap1, a multidomain, cysteinerich protein bound to actin cytoskeleton. Keap1 acts both as repressor transactivation sensor inducers. Electrophiles oxidants disrupt Keap1–Nrf2 complex, resulting nuclear accumulation Nrf2, where it enhances transcription genes via common upstream regulatory element, antioxidant response element. Reporter cotransfection–transactivation analyses with series deletion mutants revealed absence double glycine repeat domain does not bind Nrf2. In addition, either intervening region or C-terminal also abolished ability sequester indicating all these domains contribute activity Keap1. Immunocytochemical immunoprecipitation demonstrated associates filaments through its domain. Importantly, disruption cytoskeleton promotes entry an reporter protein. The therefore provides scaffolding essential for function which oxidative electrophilic stress.