Abstract
Multiple lines of evidence indicate that mitochondrial dysfunction is central to Parkinson's disease. Here we investigate the mechanism by which parkin, an E3 ubiquitin ligase, and USP30, a mitochondrion-localized deubiquitylase, regulate mitophagy. We find that mitochondrial damage stimulates parkin to assemble Lys 6, Lys 11 and Lys 63 chains on mitochondria, and that USP30 is a ubiquitin-specific deubiquitylase with a strong preference for cleaving Lys 6- and Lys 11-linked multimers. Using mass spectrometry, we show that recombinant USP30 preferentially removes these linkage types from intact ubiquitylated mitochondria and counteracts parkin-mediated ubiquitin chain formation in cells. These results, combined with a series of chimaera and localization studies, afford insights into the mechanism by which a balance of ubiquitylation and deubiquitylation regulates mitochondrial homeostasis, and suggest a general mechanism for organelle autophagy.
MeSH terms
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Carbonyl Cyanide m-Chlorophenyl Hydrazone / pharmacology
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Catalytic Domain
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Cell Extracts
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Gene Knockdown Techniques
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Green Fluorescent Proteins / metabolism
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HEK293 Cells
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HeLa Cells
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Homeostasis* / drug effects
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Humans
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Hydrogen-Ion Concentration / drug effects
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Lysine / metabolism
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Mass Spectrometry
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Membrane Potential, Mitochondrial / drug effects
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Mitochondria / drug effects
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Mitochondria / metabolism*
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Mitochondrial Proteins / chemistry
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Mitochondrial Proteins / metabolism*
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Mitophagy / drug effects
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Models, Biological
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Peroxisomes / drug effects
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Peroxisomes / metabolism
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Substrate Specificity / drug effects
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Thiolester Hydrolases / chemistry
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Thiolester Hydrolases / metabolism*
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Ubiquitin / metabolism*
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Ubiquitin-Protein Ligases / metabolism*
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Ubiquitin-Specific Proteases / metabolism
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Ubiquitination / drug effects
Substances
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Cell Extracts
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Mitochondrial Proteins
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Ubiquitin
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Usp30 protein, human
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Green Fluorescent Proteins
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Carbonyl Cyanide m-Chlorophenyl Hydrazone
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Ubiquitin-Protein Ligases
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parkin protein
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Thiolester Hydrolases
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Ubiquitin-Specific Proteases
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Lysine