The DJ-1L166P mutant protein associated with early onset Parkinson's disease is unstable and forms higher-order protein complexes.
Parkinson's disease (PD) is a common neurodegenerative disorder that involves the selective degeneration of midbrain dopaminergic neurons. Recently DJ-1 mutations have been linked to autosomal-recessive early-onset Parkinsonism in two European families. By using gel filtration assays under physiological conditions we demonstrate that DJ-1 protein forms a dimeric structure. Conversely, the DJ-1L166P mutant protein shows a different elution profile as compared with DJ-1WT both in overexpression cellular systems or in lymphoblasts cells, suggesting that it might form higher order protein structures. Furthermore we observed that the level of DJ-1L166P mutant protein in the patient's lymphoblasts was very low as compared with the wild-type protein. We excluded a potential transcriptional impairment by performing quantitative RT-PCR on the patient's material. Pulse-chase experiments in transfected COS-1 cells and cycloheximide treatment in control and patient lymphoblasts indicated that the mutant protein was rapidly degraded. This rapid turnover and the structural changes of DJ-1L166P mutant protein might be crucial in the disease pathogenesis.
Macedo
Maria G
MG
Department of Human Genetics, Section Medical Genomics, VU University Medical Center, 1081 BT Amsterdam, The Netherlands.
Anar
Burcu
B
Bronner
Iraad F
IF
Cannella
Milena
M
Squitieri
Ferdinando
F
Bonifati
Vincenzo
V
Hoogeveen
André
A
Heutink
Peter
P
Rizzu
Patrizia
P
D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D003513:Cycloheximide / Q000494:pharmacology; D019281:Dimerization; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008214:Lymphocytes / Q000378:metabolism*; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D015513:Oncogene Proteins / Q000235:genetics* / Q000378:metabolism; D010300:Parkinson Disease / Q000235:genetics* / Q000378:metabolism; D000071617:Protein Deglycase DJ-1; D011489:Protein Denaturation; D050828:Protein Inhibitors of Activated STAT; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D051843:Synucleins
D047908:Intracellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D015513:Oncogene Proteins; C501001:PIAS2 protein, human; D050828:Protein Inhibitors of Activated STAT; D011500:Protein Synthesis Inhibitors; D051843:Synucleins; D003513:Cycloheximide; C105131:PARK7 protein, human; D000071617:Protein Deglycase DJ-1