title: Site-to-site interdomain communication may mediate different loss-of-function mechanisms in a cancer-associated NQO1 polymorphism.
abstract: Disease associated genetic variations often cause intracellular enzyme inactivation, dysregulation and instability. However, allosteric communication of mutational effects to distant functional sites leading to loss-of-function remains poorly understood. We characterize here interdomain site-to-site communication by which a common cancer-associated single nucleotide polymorphism (c.C609T/p.P187S) reduces the activity and stability in vivo of NAD(P)H:quinone oxidoreductase 1 (NQO1). NQO1 is a FAD-dependent, two-domain multifunctional stress protein acting as a Phase II enzyme, activating cancer pro-drugs and stabilizing p53 and p73α oncosuppressors. We show that p.P187S causes structural and dynamic changes communicated to functional sites far from the mutated site, affecting the FAD binding site located at the N-terminal domain (NTD) and accelerating proteasomal degradation through dynamic effects on the C-terminal domain (CTD). Structural protein:protein interaction studies reveal that the cancer-associated polymorphism does not abolish the interaction with p73α, indicating that oncosuppressor destabilization largely mirrors the low intracellular stability of p.P187S. In conclusion, we show how a single disease associated amino acid change may allosterically perturb several functional sites in an oligomeric and multidomain protein. These results have important implications for the understanding of loss-of-function genetic diseases and the identification of novel structural hot spots as targets for pharmacological intervention.
authors.affiliation: Department of Physical Chemistry, Faculty of Sciences, University of Granada, Av. Fuentenueva s/n, 18071, Granada, Spain.
authors.forename: Encarnación
authors.initials: E
authors.lastname: Medina-Carmona
authors.affiliation: Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Avda. del Ferrocarril s/n, 03202, Elche, Alicante, Spain.|Instituto de Biocomputación y Física de los Sistemas Complejos (BIFI), 50009, Zaragoza, Spain.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Neira
authors.affiliation: Hospital Universitario de Canarias, Centre for Biomedical Research on Rare Diseases (CIBERER), Tenerife, Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Salido
authors.affiliation: Institute of General, Inorganic and Theoretical Chemistry, Faculty of Chemistry and Pharmacy, University of Innsbruck, Innsbruck, Austria.
authors.forename: Julian E
authors.initials: JE
authors.lastname: Fuchs
authors.affiliation: Department of Biochemistry and Molecular Biology I, Faculty of Sciences, University of Granada, Av. Fuentenueva s/n, 18071, Granada, Spain.
authors.forename: Rogelio
authors.initials: R
authors.lastname: Palomino-Morales
authors.affiliation: School of Pharmacy and Biomolecular Sciences, The University of Brighton, Brighton, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Timson
authors.affiliation: Department of Physical Chemistry, Faculty of Sciences, University of Granada, Av. Fuentenueva s/n, 18071, Granada, Spain.
authors.forename: Angel L
authors.initials: AL
authors.lastname: Pey
mesh_terms: D000494:Allosteric Regulation / Q000235:genetics; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006801:Humans; D009154:Mutation; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000737:chemistry / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics* / Q000473:pathology; D020641:Polymorphism, Single Nucleotide; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry / Q000235:genetics; D011485:Protein Binding; D011487:Protein Conformation; D000072417:Protein Domains / Q000235:genetics; D054730:Protein Interaction Domains and Motifs / Q000235:genetics; D000072160:Tumor Protein p73 / Q000737:chemistry / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000235:genetics
chemical_list: D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53; D005182:Flavin-Adenine Dinucleotide; D016660:NAD(P)H Dehydrogenase (Quinone); C447479:NQO1 protein, human; D046988:Proteasome Endopeptidase Complex