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Parkin occurs in a stable, non‐covalent, ∼110‐kDa complex in brain
Author(s) -
Van Humbeeck Cindy,
Waelkens Etienne,
Corti Olga,
Brice Alexis,
Vandenberghe Wim
Publication year - 2008
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2007.06000.x
Subject(s) - parkin , ubiquitin , ubiquitin ligase , chemistry , tetramer , biochemistry , in vivo , in vitro , microbiology and biotechnology , biophysics , biology , parkinson's disease , genetics , enzyme , gene , medicine , disease
Mutations in the gene for parkin, a 52‐kDa E3 ubiquitin ligase, are a major cause of hereditary Parkinson's disease (PD). In vitro studies have identified a large number of parkin‐interacting proteins. Whether parkin exists as a monomer or as part of a stable protein complex in vivo is uncertain. Here we demonstrate that endogenous parkin occurs in a stable, non‐covalent, ∼110‐kDa complex in native extracts from mouse brain, heart and skeletal muscle, while monomeric parkin is undetectable. Partial denaturation experiments indicate that this complex is at least a tetramer. Reported parkin‐binding partners do not show detectable association with the parkin complex on native gels. Upon overexpression in COS1, SH‐SY5Y or CHO cells, parkin accumulates predominantly as a monomer, suggesting that the interactors required for complex formation are available in limiting amounts in these cells. Importantly, PD‐linked parkin mutations significantly impair parkin complex formation. These data demonstrate that parkin oligomerizes into a stable, non‐covalent, heteromeric complex in vivo , and suggest that parkin may have as yet unidentified stable binding partners.