Oxidation of the cysteine-rich regions of parkin perturbs its E3 ligase activity and contributes to protein aggregation
Year: 2011
Type: article
Abstract: BACKGROUND: Accumulation of aberrant proteins to form Lewy bodies (LBs) is a hallmark of Parkinson's disease (PD). Ubiquitination-mediated degradation of aberrant, misfolded proteins is critical for maintaining normal cell function. Emerging evidence suggests that oxidative/nitrosative stress compromises the precisely-regulated network of ubiquitination in PD, particularly affecting parkin E3 ligase activity, and contributes to the accumulation of toxic proteins and neuronal cell death. RESULTS: To gain insight into the mechanism whereby cell stress alters parkin-mediated ubiquitination and LB formation, we investigated the effect of oxidative stress. We found significant increases in oxidation (sulfonation) and subsequent aggregation of parkin in SH-SY5Y cells exposed to the mitochondrial complex I inhibitor 1-methyl-4-phenlypyridinium (MPP+), representing an in vitro cell-based PD model. Exposure of these cells to direct oxidation via pathological doses of H2O2 induced a vicious cycle of increased followed by decreased parkin E3 ligase activity, similar to that previously reported following S-nitrosylation of parkin. Pre-incubation with catalase attenuated H2O2 accumulation, parkin sulfonation, and parkin aggregation. Mass spectrometry (MS) analysis revealed that H2O2 reacted with specific cysteine residues of parkin, resulting in sulfination/sulfonation in regions of the protein similar to those affected by parkin mutations in hereditary forms of PD. Immunohistochemistry or gel electrophoresis revealed an increase in aggregated parkin in rats and primates exposed to mitochondrial complex I inhibitors, as well as in postmortem human brain from patients with PD with LBs. CONCLUSION: These findings show that oxidative stress alters parkin E3 ligase activity, leading to dysfunction of the ubiquitin-proteasome system and potentially contributing to LB formation.
Source: Molecular Neurodegeneration
Authors: Fanjun Meng, Dongdong Yao, Yang Shi, Jonathan Kabakoff, Wei Wu, Joshua Reicher, Yuliang Ma, Bernd Moosmann, Eliezer Masliah, Stuart A Lipton, Zezong Gu
Language: English
Subfield: Clinical Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,090
Funders: American Heart Association, Dana Foundation, National Institutes of Health, National Eye Institute, National Institute of Neurological Disorders and Stroke, National Institute of Environmental Health Sciences, National Center for Complementary and Integrative Health, Eunice Kennedy Shriver National Institute of Child Health and Human Development
Awards: La Jolla Interdisciplinary Neuroscience Center Cores, Cellular/Molecular Pathophysiology of Intellectual and Developmental Disabilities, La Jolla-Parkinson's Disease Center Grant, Mu Center for Botanical Interaction Studies, AIDS-Related Neurotoxicity and Novel NMDAR Antagonists, RETINAL GANGLION CELLS: ION CHANNELS & TRANSMITTERS
OpenAlex ID: W2162305076