Summary: Researchers have found that Endophilin A1 — a gene linked to higher Parkinson’s disease risk — interferes with the brain’s ability to clear cellular waste by blocking autophagy, the cell’s recycling process.
Source: University of Queensland
Researchers at the University of Queensland report that a gene associated with increased Parkinson’s disease risk also contributes to the accumulation of cellular debris in the brain, offering a fresh perspective on the disease’s underlying biology.
Dr Adekunle Bademosi of The Queensland Brain Institute led the work and explains that the discovery shifts attention to how neurons handle damaged proteins and organelles.
“Our team found that a Parkinson’s disease–linked mutation in Endophilin A1 blocks the autophagy pathway that cells and neurons normally use to recycle waste,” Dr Bademosi said.
Autophagy is the process by which cells encapsulate and break down damaged or unnecessary components. When autophagy fails, toxic debris accumulates and neurons can degenerate — key features of Parkinson’s disease pathology.
“We already knew that depriving cells of amino acids induces autophagy and that this triggers the EndoA protein to move toward the cell membrane to begin recycling,” Dr Bademosi added. “Now we have evidence that normal synaptic activity — the electrical impulses that cause neurons to release neurotransmitters — also activates EndoA-driven autophagy at synapses.”
When Endophilin A1 is mutated in ways linked to Parkinson’s disease, the EndoA protein no longer responds properly to synaptic triggers. As a result, the debris that should be directed into the cell’s recycling pathway accumulates instead of being cleared, increasing neuronal stress and vulnerability.
Current treatments for Parkinson’s disease primarily address symptoms by replacing lost neurotransmitters or helping to clear aggregates after they form. The new findings suggest an alternative strategy: targeting the autophagy mechanism itself to prevent harmful accumulation before it leads to extensive neuronal loss.
“This research suggests it may be time to explore therapies that restore or modulate autophagy in affected neurons,” Dr Bademosi said. “Investigating compounds that can induce or fine-tune autophagy could point the way to more effective interventions for Parkinson’s disease.”
The University of Queensland study acknowledges collaboration with researchers in Professor Patrik Verstreken’s laboratory at the Flanders Institute for Biotechnology (VIB) in Belgium.
About this Parkinson’s disease and genetics research news
Author: Lisa Clarke ([email protected])
Source: University of Queensland
Contact: Lisa Clarke – University of Queensland
Image: The image is in the public domain
Original Research: Open access. “EndophilinA-dependent coupling between activity-induced calcium influx and synaptic autophagy is disrupted by a Parkinson-risk mutation” by Adekunle Bademosi et al., published in Neuron. DOI: 10.1016/j.neuron.2023.02.001
Abstract
EndophilinA-dependent coupling between activity-induced calcium influx and synaptic autophagy is disrupted by a Parkinson-risk mutation
Highlights
- Pre-synaptic Ca2+ influx induces autophagy at Drosophila synapses.
- Calcium influx alters EndoA rigidity and localization, influencing synaptic autophagy.
- Starvation and calcium influx are independent triggers for autophagosome formation.
- A Parkinson’s disease–linked mutation in EndoA1 blocks synaptic autophagy.
Summary
Neuronal activity causes use-dependent decline in protein function, and understanding how that decline is linked to local quality control has been unclear. This study demonstrates that Endophilin-A (EndoA), an endocytic protein, connects activity-induced calcium influx to synaptic autophagy and supports neuronal survival in ways relevant to Parkinson’s disease.
Using Drosophila models, the researchers show that mutations in a disordered loop of EndoA — including a variant associated with increased Parkinson’s risk — make EndoA insensitive to neuronal stimulation. Those mutations affect the protein’s dynamics: when the loop is more flexible, EndoA moves more readily within membrane nanodomains and becomes available for autophagosome formation. When the loop is more rigid, EndoA mobility is reduced and stimulation-induced autophagy is blocked.
Balanced, stimulation-induced autophagy is essential for dopaminergic neuron survival. The study further reports that a human ENDOA1 variant linked to Parkinson’s disease similarly disrupts nanodomain protein mobility and autophagy both in vivo and in human-induced dopaminergic neurons. Together, these observations reveal a mechanism by which neurons tie activity and calcium signaling to localized autophagy — a process critical for maintaining neuronal health and preventing degeneration.
These insights highlight autophagy as a potential therapeutic target in Parkinson’s disease. By focusing on mechanisms that preserve synaptic quality control, future treatments may be able to slow or prevent the progressive neuronal loss that underlies Parkinson’s symptoms.