Recombinant Human Keap1 protein (GST tag N-Terminus)

Specifications

Form

Liquid

Additional notes

Glutathione Sepharose 4 Fast Flow

General info

Function

Substrate-specific adapter of a BCR (BTB-CUL3-RBX1) E3 ubiquitin ligase complex that regulates the response to oxidative stress by targeting NFE2L2/NRF2 for ubiquitination (PubMed : 14585973, PubMed : 15379550, PubMed : 15572695, PubMed : 15601839, PubMed : 15983046, PubMed : 37339955). KEAP1 acts as a key sensor of oxidative and electrophilic stress : in normal conditions, the BCR(KEAP1) complex mediates ubiquitination and degradation of NFE2L2/NRF2, a transcription factor regulating expression of many cytoprotective genes (PubMed : 15601839, PubMed : 16006525). In response to oxidative stress, different electrophile metabolites trigger non-enzymatic covalent modifications of highly reactive cysteine residues in KEAP1, leading to inactivate the ubiquitin ligase activity of the BCR(KEAP1) complex, promoting NFE2L2/NRF2 nuclear accumulation and expression of phase II detoxifying enzymes (PubMed : 16006525, PubMed : 17127771, PubMed : 18251510, PubMed : 19489739, PubMed : 29590092). In response to selective autophagy, KEAP1 is sequestered in inclusion bodies following its interaction with SQSTM1/p62, leading to inactivation of the BCR(KEAP1) complex and activation of NFE2L2/NRF2 (PubMed : 20452972). The BCR(KEAP1) complex also mediates ubiquitination of SQSTM1/p62, increasing SQSTM1/p62 sequestering activity and degradation (PubMed : 28380357). The BCR(KEAP1) complex also targets BPTF and PGAM5 for ubiquitination and degradation by the proteasome (PubMed : 15379550, PubMed : 17046835).

Sequence similarities

Belongs to the KEAP1 family.

Post-translational modifications

Non-enzymatic covalent modifications of reactive cysteines by electrophile metabolites inactivate the BCR(KEAP1) complex (PubMed:17127771, PubMed:18251510, PubMed:29590092, PubMed:30323285). Accumulation of fumarate promotes the formation of cysteine S-succination (S-(2-succinyl)cysteine), leading to inactivate the BCR(KEAP1) complex and promote NFE2L2/NRF2 nuclear accumulation and activation (By similarity). Nitric oxide-dependent 8-Nitro-cGMP formation promotes cysteine guanylation (S-cGMP-cysteine), leading to NFE2L2/NRF2 nuclear accumulation and activation (By similarity). Itaconate, an anti-inflammatory metabolite generated in response to lipopolysaccharide, alkylates cysteines, activating NFE2L2/NRF2 (PubMed:29590092). Methylglyoxal, a reactive metabolite that accumulates when the glycolytic enzyme PGK1 is inhibited, promotes formation of a methylimidazole cross-link between proximal Cys-151 and Arg-135 on another KEAP1 molecule, resulting in an inactive dimer that inactivates the BCR(KEAP1) complex (PubMed:30323285).. Degraded via a proteasomal-independent process during selective autophagy: interaction with phosphorylated SQSTM1/p62 sequesters KEAP1 in inclusion bodies, leading to its degradation.. Auto-ubiquitinated by the BCR(KEAP1) complex (PubMed:15572695, PubMed:15983046). Quinone-induced oxidative stress, but not sulforaphane, increases its ubiquitination (PubMed:15572695, PubMed:15983046). Ubiquitination and subsequent degradation is most pronounced following prolonged exposure of cells to oxidative stress, particularly in glutathione-deficient cells that are highly susceptible to oxidative stress (PubMed:15572695, PubMed:15983046). Deubiquitinated by USP25; leading to stabilization (PubMed:37339955).

Subcellular localisation

Nucleus