Determination of α-Synuclein Protein Interactions by μMap Photoproximity Labeling.

Area of Science:

• Neuroscience
• Biochemistry
• Molecular Biology

Background:

• Fibrillar aggregates of alpha-synuclein (αS) are key pathological markers in synucleinopathies, including Parkinson's disease.
• Understanding αS interactions is crucial for elucidating both loss-of-function and toxic gain-of-function mechanisms in these disorders.

Purpose of the Study:

• To determine the interactomes of αS monomers and fibrils using micromap (μMap) photoproximity labeling.
• To compare these interactomes to understand disease-specific molecular changes.

Main Methods:

• Synthesis and characterization of αS variants with a minimally perturbing Ir catalyst for photoproximity labeling.
• Application of micromap (μMap) labeling to mouse brain lysate to identify αS-interacting proteins.
• Comparative analysis of monomer and fibril interactomes with existing proximity labeling data.

Main Results:

• Identification of distinct protein interaction networks for αS monomers versus fibrils.
• Validation of the μMap technique for its ability to resolve regional interactome differences due to its narrow labeling radius.
• Demonstration of downstream applications including Western blotting, microscopy, and primary neuron studies.

Conclusions:

• Micromap (μMap) photoproximity labeling is an effective tool for dissecting αS interactomes in the context of synucleinopathies.
• The identified interactomes provide insights into the molecular basis of αS-related neurodegeneration.
• This approach facilitates further investigation into the pathobiology of Parkinson's disease and related disorders.