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

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.

Printor, a Novel TorsinA-interacting Protein Implicated in Dystonia Pathogenesis

“…Immunofluorescence Confocal Microscopy-Cells were fixed in 4% paraformaldehyde, stained with appropriate primary and secondary antibodies, and processed for indirect immunofluorescence microscopy as described previously (16,35,(41)(42)(43). Analysis and acquisition were performed using a Zeiss LSM 510 confocal laser-scanning microscope.…”

“…Cell lysates were prepared from transfected cells and immunoprecipitations were carried out as described previously (16,35,(41)(42)(43) using the indicated antibodies, followed by the recovery of immunocomplexes with protein G-Sepharose beads (Upstate). For co-immunoprecipitations of endogenous proteins, the Seize Primary Mammalian Immunoprecipitation Kit (Pierce) was used according to the manufacturer's instructions.…”

DJ-1 inhibits TRAIL-induced apoptosis by blocking pro-caspase-8 recruitment to FADD

“…DJ-1, a conserved protein with 189 amino acids, is ubiquitously expressed but is found at particularly high levels in the testis, brain and kidney (Olzmann et al, 2004). DJ-1 was originally identified as a novel oncogene product in conjunction with the small G-protein Ras in NIH3T3 cells (Nagakubo et al, 1997).…”

Dopamine-derived Quinones Affect the Structure of the Redox Sensor DJ-1 through Modifications at Cys-106 and Cys-53

“…Overexpression of DJ-1 has a neuronal cytoprotective effect against oxidative stress (14,15), whereas DJ-1 deficiency leads to increased oxidative stress-induced cell death, both in culture and in animal models (16,17). It has also been shown that the pathogenic L166P mutation impairs the neuronal cytoprotective function of DJ-1 by jeopardizing dimer formation and protein stability (18).…”