Activation of NRF2 by Nitrosative Agents and H2O2 Involves KEAP1 Disulfide Formation

摘要: The NRF2 transcription factor regulates a major environmental and oxidative stress response. is itself negatively regulated by KEAP1, the adaptor of Cul3-ubiquitin ligase complex that marks for proteasomal degradation ubiquitination. Electrophilic compounds activate primarily inhibiting KEAP1-dependent degradation, through alkylation specific cysteines. We have examined impact on KEAP1 reactive oxygen nitrogen species, which are also inducers. found in untreated cells, fraction carried long range disulfide linking Cys226 Cys613. Exposing cells to hydrogen peroxide, nitric oxide donor spermine NONOate, hypochlorous acid, or S-nitrosocysteine further increased this promoted formation two molecules via Cys151. None these oxidants, except S-nitrocysteine, caused S-nitrosylation. A cysteine mutant preventing intermolecular prevented stabilization response whereas those intramolecular were functionally silent. Further, simultaneously inactivating thioredoxin glutathione pathways led both constitutive oxidation stabilization. propose Cys151 underlies activation species.