title: Evolutionary conserved N-terminal domain of Nrf2 is essential for the Keap1-mediated degradation of the protein by proteasome.
abstract: Under homeostatic conditions, Nrf2 activity is constitutively repressed. This process is dependent on Keap1, to which Nrf2 binds through the Neh2 domain. Since the N-terminal subdomain of Neh2 (Neh2-NT) contains evolutionarily conserved motifs, we examined the roles they play in the degradation of Nrf2. In Neh2-NT, we defined a novel motif that is distinct from the previously characterized DIDLID motif and designated it DLG motif. Deletion of Neh2-NT or mutation of the DLG motif largely abolished the Keap1-mediated degradation of Nrf2. These mutations were found to enfeeble the binding affinity of Nrf2 to Keap1. The Neh2-NT subdomain directed DLG-dependent, Keap1-independent, degradation of a reporter protein in the nucleus. By contrast, mutation of DLG did not affect the half-life of native Nrf2 protein in the nucleus under oxidative stress conditions. These results thus demonstrate that DLG motif plays essential roles in the Keap1-mediated proteasomal degradation of Nrf2 in the cytoplasm.
authors.affiliation: Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8577, Japan.
authors.forename: Yasutake
authors.initials: Y
authors.lastname: Katoh
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Iida
authors.forename: Moon-Il
authors.initials: MI
authors.lastname: Kang
authors.forename: Akira
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Mio
authors.initials: M
authors.lastname: Mizukami
authors.forename: Kit I
authors.initials: KI
authors.lastname: Tong
authors.forename: Michael
authors.initials: M
authors.lastname: McMahon
authors.forename: John D
authors.initials: JD
authors.lastname: Hayes
authors.forename: Ken
authors.initials: K
authors.lastname: Itoh
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamamoto
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D020816:Amino Acid Motifs; D000818:Animals; D019556:COS Cells; D002467:Cell Nucleus / Q000378:metabolism; D002522:Chlorocebus aethiops; D017124:Conserved Sequence; D003593:Cytoplasm / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019143:Evolution, Molecular; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006207:Half-Life; D006801:Humans; D000072019:Kelch-Like ECH-Associated Protein 1; D007930:Leucine / Q000737:chemistry; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D008969:Molecular Sequence Data; D051267:NF-E2-Related Factor 2; D041681:NIH 3T3 Cells; D018384:Oxidative Stress; D010957:Plasmids; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014452:Ubiquitins / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; C117301:Keap1 protein, mouse; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; C495636:Nfe2l2 protein, mouse; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; D014452:Ubiquitins; D049452:Green Fluorescent Proteins; D008156:Luciferases; D046988:Proteasome Endopeptidase Complex; D007930:Leucine