Familial Parkinson's Disease-associated L166P Mutation Disrupts DJ-1 Protein Folding and Function

James A Olzmann,Keith Brown,Keith D Wilkinson,Howard D Rees,Qing Huai,Hengming Ke,Allan I Levey,Lian Li,Lih-Shen Chin

doi:10.1074/jbc.m311017200

James A Olzmann, Keith Brown + Show 7 more

Open Access

https://doi.org/10.1074/jbc.m311017200

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Abstract

Mutations in DJ-1, a protein of unknown function, were recently identified as the cause for an autosomal recessive, early onset form of familial Parkinson's disease. Here we report that DJ-1 is a dimeric protein that exhibits protease activity but no chaperone activity. The protease activity was abolished by mutation of Cys-106 to Ala, suggesting that DJ-1 functions as a cysteine protease. Our studies revealed that the Parkinson's disease-linked L166P mutation impaired the intrinsic folding propensity of DJ-1 protein, resulting in a spontaneously unfolded structure that was incapable of forming a homodimer with itself or a heterodimer with wild-type DJ-1. Correlating with the disruption of DJ-1 structure, the L166P mutation abolished the catalytic function of DJ-1. Furthermore, as a result of protein misfolding, the L166P mutant DJ-1 was selectively polyubiquitinated and rapidly degraded by the proteasome. Together these findings provide insights into the molecular mechanism by which loss-of-function mutations in DJ-1 lead to Parkinson's disease.

Highlights

Parkinson’s disease (PD)1 is an age-related neurodegenerative movement disorder characterized by the degeneration of dopaminergic neurons in the substantia nigra and the presence of intraneuronal inclusions known as Lewy bodies [1, 2]
Proteolysis Inhibitor Treatment of Cells—HeLa or SH-SY5Y cells expressing wild-type or L166P mutant DJ-1 were incubated for 8 h at 37 °C with the proteasome inhibitor MG132 (20 ␮M, Calbiochem), the lysosomal protease inhibitor chloroquine (100 ␮M, Sigma), or vehicle (dimethyl sulfoxide (Me2SO); final concentration, 0.1%)
The lower molecular weight bands in the recombinant DJ-1 lanes are likely to be the proteolytic products of DJ-1 because they varied from blot to blot, and none of these bands were detected when the blots were analyzed with anti-DJ-1 antibodies preabsorbed with DJ-1 immunogens

Summary

Introduction

Parkinson’s disease (PD)1 is an age-related neurodegenerative movement disorder characterized by the degeneration of dopaminergic neurons in the substantia nigra and the presence of intraneuronal inclusions known as Lewy bodies [1, 2]. Our studies revealed that the Parkinson’s disease-linked L166P mutation impaired the intrinsic folding propensity of DJ-1 protein, resulting in a spontaneously unfolded structure that was incapable of forming a homodimer with itself or a heterodimer with wild-type DJ-1.

Results

Conclusion