title: Mitochondrial localization of the Parkinson's disease related protein DJ-1: implications for pathogenesis.
abstract: Both homozygous (L166P, M26I, deletion) and heterozygous mutations (D149A, A104T) in the DJ-1 gene have been identified in Parkinson's disease (PD) patients. The biochemical function and subcellular localization of DJ-1 protein have not been clarified. To date the localization of DJ-1 protein has largely been described in studies over-expressing tagged DJ-1 protein in vitro. It is not known whether the subcellular localization of over-expressed DJ-1 protein is identical to that of endogenously expressed DJ-1 protein both in vitro and in vivo. To clarify the subcellular localization and function of DJ-1, we generated three highly specific antibodies to DJ-1 protein and investigated the subcellular localization of endogenous DJ-1 protein in both mouse brain tissues and human neuroblastoma cells. We have found that DJ-1 is widely distributed and is highly expressed in the brain. By cell fractionation and immunogold electron microscopy, we have identified an endogenous pool of DJ-1 in mitochondrial matrix and inter-membrane space. To further investigate whether pathogenic mutations might prevent the distribution of DJ-1 to mitochondria, we generated human neuroblastoma cells stably transfected with wild-type (WT) or mutant (M26I, L166P, A104T, D149A) DJ-1 and performed mitochondrial fractionation and confocal co-localization imaging studies. When compared with WT and other mutants, L166P mutant exhibits largely reduced protein level. However, the pathogenic mutations do not alter the distribution of DJ-1 to mitochondria. Thus, DJ-1 is an integral mitochondrial protein that may have important functions in regulating mitochondrial physiology. Our findings of DJ-1's mitochondrial localization may have important implications for understanding the pathogenesis of PD.
authors.affiliation: Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Mika
authors.initials: M
authors.lastname: Shimoji
authors.forename: Bobby
authors.initials: B
authors.lastname: Thomas
authors.forename: Darren J
authors.initials: DJ
authors.lastname: Moore
authors.forename: Seong-Woon
authors.initials: SW
authors.lastname: Yu
authors.forename: Neena I
authors.initials: NI
authors.lastname: Marupudi
authors.forename: Reidun
authors.initials: R
authors.lastname: Torp
authors.forename: Ingeborg A
authors.initials: IA
authors.lastname: Torgner
authors.forename: Ole P
authors.initials: OP
authors.lastname: Ottersen
authors.forename: Ted M
authors.initials: TM
authors.lastname: Dawson
authors.forename: Valina L
authors.initials: VL
authors.lastname: Dawson
mesh_terms: D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006579:Heterozygote; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins; D008854:Microscopy, Electron; D008928:Mitochondria / Q000378:metabolism; D009154:Mutation; D015513:Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D010300:Parkinson Disease / Q000378:metabolism*; D000071617:Protein Deglycase DJ-1; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D015513:Oncogene Proteins; C105131:PARK7 protein, human; D000071617:Protein Deglycase DJ-1