Unexpected mitochondrial matrix localization of Parkinson's disease-related DJ-1 mutants but not wild-type DJ-1.
DJ-1 has been identified as a gene responsible for recessive familial Parkinson's disease (familial Parkinsonism), which is caused by a mutation in the PARK7 locus. Consistent with the inferred correlation between Parkinson's disease and mitochondrial impairment, mitochondrial localization of DJ-1 and its implied role in mitochondrial quality control have been reported. However, the mechanism by which DJ-1 affects mitochondrial function remains poorly defined, and the mitochondrial localization of DJ-1 is still controversial. Here, we show the mitochondrial matrix localization of various pathogenic and artificial DJ-1 mutants by multiple independent experimental approaches including cellular fractionation, proteinase K protection assays, and specific immunocytochemistry. Localization of various DJ-1 mutants to the matrix is dependent on the membrane potential and translocase activity in both the outer and the inner membranes. Nevertheless, DJ-1 possesses neither an amino-terminal alpha-helix nor a predictable matrix-targeting signal, and a post-translocation processing-derived molecular weight change is not observed. In fact, wild-type DJ-1 does not show any evidence of mitochondrial localization at all. Such a mode of matrix localization of DJ-1 is difficult to explain by conventional mechanisms and implies a unique matrix import mechanism for DJ-1 mutants.
Ubiquitin Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.|Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan.
Waka
W
Kojima
Ubiquitin Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.|Tachikawa Hospital, 4-2-22 Nishikimachi, Tachikawa, Tokyo, 190-8531, Japan.|Department of Neurology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo, 160-8582, Japan.
Yuki
Y
Kujuro
Ubiquitin Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.|Structural Biology Laboratory, Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo, 113-0032, Japan.
Kei
K
Okatsu
Ubiquitin Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.|Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.
Queliconi
Q
Bruno
Ubiquitin Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.
Fumika
F
Koyano
Ubiquitin Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.|Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.
Mayumi
M
Kimura
Ubiquitin Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.
Koji
K
Yamano
Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan.|Laboratory of Protein Metabolism, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.
Keiji
K
Tanaka
Ubiquitin Project, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya, Tokyo, 156-8506, Japan.|PRESTO, JST, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
Noriyuki
N
Matsuda
D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000235:genetics*; D008928:Mitochondria / Q000235:genetics; D051336:Mitochondrial Membranes / Q000737:chemistry; D050505:Mutant Proteins / Q000235:genetics* / Q000302:isolation & purification; D009154:Mutation; D010300:Parkinson Disease / Q000235:genetics* / Q000473:pathology; D000071617:Protein Deglycase DJ-1 / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification
D050505:Mutant Proteins; C105131:PARK7 protein, human; D000071617:Protein Deglycase DJ-1