L166P mutant DJ-1, causative for recessive Parkinson's disease, is degraded through the ubiquitin-proteasome system
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Updated: Sep 23, 2026
Gait Analysis of Age-dependent Motor Impairments in Mice with Neurodegeneration
Published on: June 18, 2018
David W Miller1, Rili Ahmad, Stephen Hague
1Laboratory of Neurogenetics, NIA, National Institutes of Health, Bethesda, Maryland 20892-1589, USA.
Abstract:
Mutations in a gene on chromosome 1, DJ-1, have been reported recently to be associated with recessive, earlyonset Parkinson's disease. While one mutation is a large deletion that is predicted to produce an effective knockout of the gene, the second is a point mutation, L166P, whose precise effects on protein function are unclear. In the present study, we show that L166P destabilizes DJ-1 protein and promotes its degradation through the ubiquitin-proteasome system. A double mutant (K130R, L166P) was more stable than L166P, suggesting that this lysine residue contributes to stability of the protein. Subcellular localization was broadly similar for both wild type and L166P forms of the protein, indicating that the effect of the mutation is predominantly on protein stability. These observations are reminiscent of other recessive gene mutations that produce an effective loss of function. The L166P mutation has the simple effect of promoting DJ-1 degradation, thereby reducing net DJ-1 protein within the cell.
Insights
The L166P mutation destabilizes DJ-1 protein, leading to its degradation and reduced levels in cells. This finding clarifies the impact of DJ-1 mutations in early-onset Parkinson's disease.
Area of Science:
- Neuroscience
- Genetics
- Molecular Biology
Background:
- Mutations in the DJ-1 gene on chromosome 1 are linked to recessive, early-onset Parkinson's disease.
- A large deletion causes DJ-1 knockout, but the functional impact of the L166P point mutation remains unclear.
Purpose of the Study:
- To investigate the precise effects of the L166P mutation on DJ-1 protein function and stability.
- To elucidate the mechanism by which the L166P mutation contributes to Parkinson's disease pathogenesis.
Main Methods:
- Protein stability assays were performed on wild-type and mutant DJ-1 proteins.
- Ubiquitin-proteasome system involvement was assessed.
- Subcellular localization studies were conducted for wild-type and L166P DJ-1.
Main Results:
- The L166P mutation significantly destabilizes DJ-1 protein, promoting its degradation via the ubiquitin-proteasome system.
- A double mutant (K130R, L166P) exhibited increased stability compared to L166P, indicating a role for lysine at position 130 in protein stability.
- Subcellular localization of L166P DJ-1 was similar to wild-type, suggesting the primary effect is on protein stability rather than cellular distribution.
Conclusions:
- The L166P mutation primarily affects DJ-1 protein stability, leading to increased degradation and reduced cellular DJ-1 levels.
- This loss-of-function mechanism is consistent with other recessive DJ-1 mutations associated with Parkinson's disease.
- Understanding the impact of L166P on DJ-1 stability provides insights into the molecular basis of early-onset Parkinson's disease.
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