title: Parkinson's disease-associated mutations in DJ-1 modulate its dimerization in living cells.
abstract: Mutations in the protein DJ-1 cause recessive forms of early onset familial Parkinson's disease (PD). To date, most of the causative mutations studied destabilize formation of DJ-1 homodimers, which appears to be closely linked to its normal function in oxidative stress and other cellular processes. Despite the importance of understanding the dimerization dynamics of this protein, this aspect of DJ-1 biology has not previously been directly studied in living cells. Here, we use bimolecular fluorescence complementation to study DJ-1 dimerization and find not only that DJ-1 forms homodimers in living cells but that most PD causative DJ-1 mutations disrupt this process, including the L166P, M26I, L10P, and P158∆ mutations. Interestingly, the E64D mutant form of DJ-1 retains the ability to form homodimers. However, while wild-type DJ-1 dimers are stabilized under oxidative stress conditions, we find that the E64D mutation blocks this stabilization. Furthermore, our data show that the E64D mutation potentiates the formation of aggresomes containing DJ-1. We also observe that while the widely studied L166P mutation prevents DJ-1 from forming homodimers or heterodimers with wild-type protein, the mutant protein is able to partially disrupt formation of wild-type homodimers. In summary, by investigating DJ-1 dimerization in living cells, we have uncovered several novel properties of PD causative mutations in DJ-1, which may ultimately provide novel insight into PD pathogenesis and possible therapeutic options.
authors.affiliation: Department of Genetics, University of Leicester, Leicester, UK.
authors.forename: Mariaelena
authors.initials: M
authors.lastname: Repici
authors.forename: Kornelis R
authors.initials: KR
authors.lastname: Straatman
authors.forename: Nadia
authors.initials: N
authors.lastname: Balduccio
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Enguita
authors.forename: Tiago F
authors.initials: TF
authors.lastname: Outeiro
authors.forename: Flaviano
authors.initials: F
authors.lastname: Giorgini
mesh_terms: D019943:Amino Acid Substitution; D015870:Gene Expression; D005822:Genetic Vectors; D057809:HEK293 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D008958:Models, Molecular; D009154:Mutation; D015513:Oncogene Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress; D010300:Parkinson Disease / Q000378:metabolism / Q000473:pathology; D000071617:Protein Deglycase DJ-1; D055503:Protein Multimerization / Q000187:drug effects; D055550:Protein Stability; D014162:Transfection
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D015513:Oncogene Proteins; D006861:Hydrogen Peroxide; C105131:PARK7 protein, human; D000071617:Protein Deglycase DJ-1