title: Interference with ubiquitination causes oxidative damage and increased protein nitration: implications for neurodegenerative diseases.
abstract: Inhibition of the proteasomal pathway for degrading abnormal proteins leads to protein aggregation, increased oxidative damage and increased protein nitration. We now show that interference with polyubiquitination has similar consequences. Expression of a dominant-negative mutant form of ubiquitin (K48R) in NT-2 and SK-N-MC cells caused decreased cell growth rates and increased oxidative damage (protein carbonyls and lipid peroxidation), nitric oxide production and elevated protein nitration. It also rendered cells highly sensitive to 4-hydroxy-2,3-trans-nonenal, a neurotoxic end-product of lipid peroxidation, hydrogen peroxide and deprivation of growth factors. Overexpression of wild-type ubiquitin did not produce these effects. Our data show that interference with the ubiquitin-proteasome pathway at a different point and by a different mechanism can produce many of the common features of human neurodegenerative diseases, such as increased lipid peroxidation, protein oxidation and protein nitration. We suggest that defects in this pathway at multiple points could produce the common features of neurodegenerative diseases, and that more such defects remain to be discovered.
authors.affiliation: Neurodegenerative Disease Research Centre, GKT School of Biomedical Sciences, King's College, London, UK.
authors.forename: Dong-Hoon
authors.initials: DH
authors.lastname: Hyun
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Gray
authors.forename: Barry
authors.initials: B
authors.lastname: Halliwell
authors.forename: Peter
authors.initials: P
authors.lastname: Jenner
mesh_terms: D000447:Aldehydes / Q000494:pharmacology; D000975:Antioxidants / Q000378:metabolism; D002455:Cell Division / Q000235:genetics; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D002999:Clone Cells; D003546:Cysteine Endopeptidases / Q000187:drug effects / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005799:Genes, Dominant; D005978:Glutathione / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics; D009097:Multienzyme Complexes / Q000187:drug effects / Q000378:metabolism; D009154:Mutation; D009447:Neuroblastoma / Q000188:drug therapy / Q000378:metabolism; D019636:Neurodegenerative Diseases / Q000209:etiology / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress / Q000502:physiology*; D046988:Proteasome Endopeptidase Complex; D011506:Proteins / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D018243:Teratocarcinoma / Q000188:drug therapy / Q000378:metabolism; D014162:Transfection; D014452:Ubiquitins / Q000235:genetics / Q000378:metabolism*
chemical_list: D000447:Aldehydes; D000975:Antioxidants; D004791:Enzyme Inhibitors; D008164:Luminescent Proteins; D009097:Multienzyme Complexes; D009566:Nitrates; D009573:Nitrites; D016877:Oxidants; D011506:Proteins; D011993:Recombinant Fusion Proteins; D014452:Ubiquitins; D049452:Green Fluorescent Proteins; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; D005978:Glutathione; C027576:4-hydroxy-2-nonenal