E46K-like α-synuclein mutants increase lipid interactions and disrupt membrane selectivity.

Area of Science:

• Neuroscience
• Biochemistry
• Molecular Biology

Background:

• Parkinson's disease (PD) is a common neurodegenerative disorder linked to alpha-synuclein (αSyn) aggregation.
• Mutations in αSyn, like E46K, exacerbate PD pathogenesis by affecting its membrane interactions.
• E46K-like mutants cause dopaminergic neuron loss and motor deficits in preclinical models.

Purpose of the Study:

• To investigate the molecular pathology of E46K-like αSyn mutants.
• To characterize their structure, membrane-binding, and remodeling properties.
• To determine the mechanism underlying their detrimental effects in synucleinopathies.

Main Methods:

• Biophysical techniques were employed to study αSyn mutant structure and function.
• Membrane-binding avidity and curvature selectivity were assessed.
• Subcellular localization and effects on neuronal models were analyzed.

Main Results:

• E46K-like αSyn mutants show a slight increase in avidity for synaptic vesicle membranes.
• The primary defect is a complete loss of αSyn's curvature selectivity.
• Mutants exhibit indiscriminate binding, leading to altered subcellular localization and cellular stress.

Conclusions:

• Loss of αSyn curvature selectivity, not increased membrane affinity, is critical in synucleinopathies.
• Altered αSyn localization disrupts normal synaptic function and contributes to neurodegeneration.
• These findings offer insights into PD pathogenesis and potential therapeutic targets.