title: Molecular effects of cancer-associated somatic mutations on the structural and target recognition properties of Keap1.
abstract: Kelch-like ECH-associated protein 1 (Keap1) plays an important regulatory role in the nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent oxidative stress response pathway. It functions as a repressor of Nrf2, a key transcription factor that initiates the expression of cytoprotective enzymes during oxidative stress to protect cells from damage caused by reactive oxygen species. Recent studies show that mutations of Keap1 can lead to aberrant activation of the antioxidant pathway, which is associated with different types of cancers. To gain a mechanistic understanding of the links between Keap1 mutations and cancer pathogenesis, we have investigated the molecular effects of a series of mutations (G333C, G350S, G364C, G379D, R413L, R415G, A427V, G430C and G476R) on the structural and target recognition properties of Keap1 by using nuclear magnetic resonance (NMR) spectroscopy, circular dichroism (CD) and isothermal titration calorimetry (ITC). Depending on their locations in the protein, these mutations are found to exert differential effects on the protein stability and target binding. Together with the proposed hinge-and-latch mechanism of Nrf2-Keap1 binding in the literature, our results provide important insight into the molecular affect of different somatic mutations on Keap1's function as an Nrf2 repressor.
authors.affiliation: *Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada, N6A 5C1.
authors.forename: Halema
authors.initials: H
authors.lastname: Khan
authors.affiliation: *Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada, N6A 5C1.
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Killoran
authors.affiliation: *Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada, N6A 5C1.
authors.forename: Anne
authors.initials: A
authors.lastname: Brickenden
authors.affiliation: †Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543, Singapore.
authors.forename: Jingsong
authors.initials: J
authors.lastname: Fan
authors.affiliation: †Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543, Singapore.
authors.forename: Daiwen
authors.initials: D
authors.lastname: Yang
authors.affiliation: *Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada, N6A 5C1.
authors.forename: Wing-Yiu
authors.initials: WY
authors.lastname: Choy
mesh_terms: D019943:Amino Acid Substitution; D002942:Circular Dichroism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000072019:Kelch-Like ECH-Associated Protein 1; D007700:Kinetics; D008024:Ligands; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism; D008958:Models, Molecular; D051267:NF-E2-Related Factor 2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017354:Point Mutation; D011487:Protein Conformation; D017510:Protein Folding; D054730:Protein Interaction Domains and Motifs; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D055550:Protein Stability; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017384:Sequence Deletion; D013947:Thymosin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C431364:KEAP1 protein, human; D000072019:Kelch-Like ECH-Associated Protein 1; D008024:Ligands; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D009363:Neoplasm Proteins; D010446:Peptide Fragments; D011498:Protein Precursors; D011994:Recombinant Proteins; C040782:prothymosin alpha; D013947:Thymosin